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2022

A paper on the densification of tungsten by laser AM and the mechanism of crystal orientation control was published as an OA paper in Scripta Materialia (IF=5.6).

Tsubasa Todo, Takuya Ishimoto, Ozkan Gokcekaya, Jongyeong Oh, Takayoshi Nakano*:
Single crystalline-like crystallographic texture formation of pure tungsten through laser powder bed fusion,
Scripta Materialia, 206, (2022), 114252; 1-6.
https://doi.org/10.1016/j.scriptamat.2021.114252

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Abstract We successfully formed the first prominent crystallographic texture of tungsten using laser powder bed fusion (LPBF). It is difficult even to manufacture highly dense tungsten products using LPBF because of its extremely high melting point and high thermal conductivity. By tuning the laser process parameters, we succeeded in fabricating almost fully dense pure tungsten parts with a relative density of 99.1%, which is the highest value yet to be reported. More importantly, a single crystalline-like prominent crystallographic texture evolved, in which <011> preferentially oriented in the scanning direction. This texture was formed to reduce the crystal misorientation at the melt pool center, at which the solidification fronts from the right and left halves of the melt pool encounter. This texture formation mechanism is similar to that of conventional alloys with ordinary thermal properties; however, the crystal growth directionality that governs the crystallographic orientation differs according to the melt pool morphology.

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2021

We succeeded in forming high-melting-point W with reduced crack formation by changing the powder preparation method using laser metal 3D printing (L-PBF), and the paper proving it in cyber-physical space was published as an OA paper in AM Letters.

Ozkan Gokcekaya, Takuya Ishimoto, Tsubasa Todo, Pan Wang, Nakano Takayoshi*:
Influence of powder characteristics on densification via crystallographic texture formation: Pure tungsten prepared by laser powder bed fusion,
Additive Manufacturing Letters, 1, (2021), 100016; 1-8.
https://doi.org/10.1016/j.addlet.2021.100016

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Abstract
The laser powder bed fusion (LPBF) of pure tungsten for the fabrication of near-fully dense components is challenging owing to the intrinsic properties of tungsten. In this study, routine, gas-atomized, and plasma-processed tungsten powder samples were characterized for their powder shape, size distribution, tapped density, and flowability, and then used to fabricate parts using identical LPBF process parameters to evaluate the influence of the powder characteristics on the metal densification and microstructure. The plasma-processed W powder showed a relative density of 98.7%, the highest value yet to be reported, at a baseplate temperature of 80°C owing to the higher tapped density and improved flowability of the powder, which result in high-quality powder bed formation. In addition, numerical simulations were conducted to estimate the effect of the powder quality on laser energy absorption and, thus, melt pool formation. The results reveal that enhanced powder characteristics result in an increased density and prevent lack of fusion while tuning the grain boundary characteristics and strengthening the crystallographic texture, which resulted in decreased cracking owing to less crack-sensitive grain boundaries and increased hardness of the as-built W components.

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【 paper 】We succeeded in forming high-melting-point W with reduced crack formation by changing the powder preparation method using laser metal 3D printing (L-PBF), and the paper proving it in cyber-physical space was published as an OA paper in Additive M

Ozkan Gokcekaya, Takuya Ishimoto, Tsubasa Todo, Pan Wang, Nakano Takayoshi*:
Influence of powder characteristics on densification via crystallographic texture formation: Pure tungsten prepared by laser powder bed fusion,
Additive Manufacturing Letters, 1, (2021), 100016; 1-8.
https://doi.org/10.1016/j.addlet.2021.100016

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Abstract
The laser powder bed fusion (LPBF) of pure tungsten for the fabrication of near-fully dense components is challenging owing to the intrinsic properties of tungsten. In this study, routine, gas-atomized, and plasma-processed tungsten powder samples were characterized for their powder shape, size distribution, tapped density, and flowability, and then used to fabricate parts using identical LPBF process parameters to evaluate the influence of the powder characteristics on the metal densification and microstructure. The plasma-processed W powder showed a relative density of 98.7%, the highest value yet to be reported, at a baseplate temperature of 80°C owing to the higher tapped density and improved flowability of the powder, which result in high-quality powder bed formation. In addition, numerical simulations were conducted to estimate the effect of the powder quality on laser energy absorption and, thus, melt pool formation. The results reveal that enhanced powder characteristics result in an increased density and prevent lack of fusion while tuning the grain boundary characteristics and strengthening the crystallographic texture, which resulted in decreased cracking owing to less crack-sensitive grain boundaries and increased hardness of the as-built W components.

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A paper on the difference of powder bed fusion by using electron beam and laser beam as heat sources has been published as an open access paper in Additive Manufacturing (IF=11).

Shi-Hai Sun, Koji Hagihara, Takuya Ishimoto, Ryoya Suganuma, Yun-Fei Xue, Takayoshi Nakano:
Comparison of microstructure, crystallographic texture, and mechanical properties in Ti–15Mo–5Zr–3Al alloys fabricated via electron and laser beam powder bed fusion technologies
Additive Manufacturing, 47, (2021), 102329; 1-17.
https://doi.org/10.1016/j.addma.2021.102329

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Abstract
Depending on the application, establishing a strategy for selecting the type of powder bed fusion technology from electron beam (EB-PBF) or laser powder bed fusion (L-PBF)—is important. In this study, we focused on the β-type Ti–15Mo–5Zr–3Al alloy (expected for hard-tissue implant applications) as a model material, and we examined the variations in the microstructure, crystallographic texture, and resultant mechanical properties of specimens fabricated by L-PBF and EB-PBF. Because the melting mode transforms from the conduction mode to the keyhole mode with an increase in the energy density in L-PBF, the relative density of the L-PBF-built specimen decreases at higher energy densities, unlike that of the EB-PBF-built specimen. Although both EB-PBF and LPBF can obtain cubic crystallographic textures via bidirectional scanning with a 90° rotation in each layer, the formation mechanisms of the textures were found to be different. The <100> texture in the build direction is mainly derived from the vertically grown columnar cells in EB-PBF, whereas it is derived from the vertically and horizontally grown columnar cells in L-PBF. Consequently, different textures were developed via bidirectional scanning without rotation in each layer: the <110>and <100>aligned textures along the build direction in LPBF and EB-PBF, respectively. The L-PBF-built specimen exhibited considerably better ductility, but slightly lower strength than the EB-PBF-built specimen, under the conditions of the same crystallographic texture and relative density. We attributed this to the variation in the microstructures of the specimens; the formation of the α-phase was completely absent in the L-PBF-built specimen. The results demonstrate the importance of properly selecting the two technologies according to the material and its application.

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A paper on kink strengthening of Mg-Zn-Y alloys containing LPSO layers as nanoplates has been published as an open access paper in Materials Research Letters.

Koji Hagihara*, Ryohei Ueyama, Toko Tokunaga, Michiaki Yamasaki, Yoshihito Kawamura, Takayoshi Nakano
Quantitative estimation of kink-band strengthening in an Mg–Zn–Y single crystal with LPSO nanoplates
Materials Research Letters, 9 (2021) 467-474.
https://doi.org/10.1080/21663831.2021.1974593

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Abstract
Kink-band strengthening was first quantitatively evaluated using an Mg–Zn–Y single crystal containing long-period stacking ordered (LPSO) nanoplates. The ability of a kink-band boundary to act as a barrier that hinders the motion of dislocations is high and comparable to that of a general random grain boundary. Nevertheless, a kink-band boundary is regarded as a simple tilt boundary in the dislocation model. One reason for the anomalous ability of kink-band boundary acting as barriers is related to its peculiar hierarchical structure, in which many small kink bands with high crystal rotation angles accumulate in a localized region. By the quantitative estimation using the single crystal, the origin of the anomalous ability of kink bands acting as barriers that hinder the motion of dislocation was elucidated.

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A paper on deformation behavior of powder/solid composites with a honeycomb structure has been published in Crystals (MDPI: IF=2.6) as an open access article. The results on the control of crystallographic microstructure and mechanical properties of nick

Naoko Ikeo*, Tatsuya Matsumi, Takuya Ishimoto, Ryosuke Ozasa, Aira Matsugaki, Tadaaki Matsuzaka, Ozkan Gokcekaya, Yorinobu Takigawa, Takayoshi Nakano*:
Fabrication of Ti-Alloy Powder/Solid Composite with Uniaxial Anisotropy by Introducing Unidirectional Honeycomb Structure via Electron Beam Powder Bed Fusion,
Crystals, 11 [9], (2021), 1074;1-11.
https://doi.org/10.3390/cryst11091074

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Abstract:
In this study, a Ti–6Al–4V alloy composite with uniaxial anisotropy and a hierarchical structure is fabricated using electron beam powder bed fusion, one of the additive manufacturing techniques that enable arbitrary fabrication, and subsequent heat treatment. The uniaxial anisotropic deformation behavior and mechanical properties such as Young’s modulus are obtained by introducing a unidirectional honeycomb structure. The main feature of this structure is that the unmelted powder retained in the pores of the honeycomb structure. After appropriate heat treatment at 1020 °C, necks are formed between the powder particles and between the powder particles and the honeycomb wall, enabling a stress transmission through the necks when the composite is loaded. This means that the powder part has been mechanically functionalized by the neck formation. As a result, a plateau region appears in the stress–strain curve. The stress transfer among the powder particles leads to the cooperative deformation of the composites, contributing to the excellent energy absorption capacity. Therefore, it is expected that the composite can be applied to bone plates on uniaxially oriented microstructures such as long bones owing to its excellent energy absorption capacity and low elasticity to unidirectionally suppress stress shielding.

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The results on the control of crystallographic microstructure and mechanical properties of nickel-based superalloy (Hastelloy-X) by the LPBF method have been published as an open access article in Crystals (MDPI, IF=2.6).

Shinya Hibino*, Tsubasa Todo, Takuya Ishimoto, Ozkan Gokcekaya, Yuichiro Koizumi, Kenichiroh Igashira, Takayoshi Nakano*:
Control of Crystallographic Texture and Mechanical Properties of Hastelloy-X via Laser Powder Bed Fusion,
Crystals, 11(9), (2021), 1064;
https://doi.org/10.3390/cryst11091064
*: Corresponding author

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Abstract
The influence of various laser powder bed fusion (LPBF) process parameters on the crystallographic textures and mechanical properties of a typical Ni-based solid-solution strengthened alloy, Hastelloy-X, was examined. Samples were classified into four groups based on the type of crystallographic texture: single crystalline-like microstructure with <100>//build direction (BD) (<100>-SCM), single crystalline-like microstructure with <110>//BD (<110>-SCM), crystallographic lamellar microstructure (CLM), or polycrystalline microstructure (PCM). These four crystallographic textures were realized in Hastelloy-X for the first time here to the best of our knowledge. The mechanical properties of the samples varied depending on their texture. The tensile properties were affected not only by the Schmid factor but also by the grain size and the presence of lamellar boundaries (grain boundaries). The lamellar boundaries at the interface between the <110>//BD oriented main layers and the <100>//BD-oriented sub-layers of CLM contributed to the resistance to slip transmission and the increased proof stress. It was possible to control a wide range of crystallographic microstructures via the LPBF process parameters, which determines the melt pool morphology and solidification behavior.

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A joint research paper with Tokyo Dental College was published in the International Journal of Implant Dentistry.

Yuto Otsu*, Satoru Matsunaga, Takehiro Furukawa, Kei Kitamura, Masaaki Kasahara, Shinichi Abe, Takayoshi Nakano, Takuya Ishimoto, Yasutomo Yajima
Structural characteristics of the bone surrounding dental implants placed into the tail-suspended mice
International Journal of Implant Dentistry, 7, (2021), 89;1-10.
https://doi.org/10.1186/s40729-021-00374-3

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Abstract
[ Background ] There are many unclear points regarding local structural characteristics of the bone surrounding the implant reflecting the mechanical environment.
Purpose: The purpose of this study is to quantitatively evaluate bone quality surrounding implants placed into the femurs of mice in an unloading model, and to determine the influence of the mechanical environment on bone quality.
[ Methods ]: Twenty 12-week-old male C57BL6/NcL mice (n = 5/group) were used as experimental animals. The mice were divided into two groups: the experimental group (n = 10) which were reared by tail suspension, and the control group (n = 10) which were reared normally. An implant was placed into the femur of a tail-suspended mouse, and after the healing period, they were sacrificed and the femur was removed. After micro-CT imaging, Villanueva osteochrome bone stain was performed. It was embedded in unsaturated polyester resin. The
polymerized block was sliced passing through the center of the implant body. Next, 100-μm-thick polished specimens were prepared with water-resistant abrasive paper. In addition to histological observation, morphometric evaluation of cancellous bone was performed, and the anisotropy of collagen fibers and biological apatite (BAp) crystals was analyzed.
[ Results ]: As a result, the femoral cortical bone thickness and new peri-implant bone mass showed low values in the tail suspension group. The uniaxial preferential orientation of BAp c-axis in the femoral long axis direction in the non-implant groups, but biaxial preferential orientation of BAp c-axis along the long axis of implant and femoral long axis direction were confirmed in new bone reconstructed by implant placement. Collagen fiber running anisotropy and orientation of BAp c-axis in the bone surrounding the implant were not significantly different due to tail suspension.
[ Conclusions ]: From the above results, it was clarified that bone formation occurs surrounding the implant even under extremely low load conditions, and bone microstructure and bone quality adapted to the new mechanical environment are acquired.
Keywords: Tail suspension, Femur, Bone quality, Biological apatite orientation, Collagen fiber, Dental implant

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A paper on the difference of surface residual stress and phase stability between laser beam and electron beam in β-type titanium alloy was published as an open access article in Additive Manufacturing (IF=11).

Aya Takase*, Takuya Ishimoto, Ryoya Suganuma, Takayoshi Nakano*:
Surface residual stress and phase stability in unstable β-type Ti-15Mo-5Zr-3Al alloy manufactured by laser and electron beam powder bed fusion technologies,
Additive Manufacturing, 47, (2021), 102257; 1-14.
https://doi.org/10.1016/j.addma.2021.102257

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Abstract

The differences between the physicochemical properties of the laser and electron beam powder bed fusion (L- and EB-PBF) methods are yet to be explored further. In particular, the differences in the residual stress and phase stability of alloys with unstable phases remain unexplored. The present work is the first to systematically investigate how the heat source type and process parameters affect the surface residual stress and phase stability of an unstable β-type titanium alloy, Ti-15Mo-5Zr-3Al. The surface residual stress and β-phase behavior were studied using high-precision X-ray diffraction (HP-XRD). Significant differences were observed between the two methods. The L-PBF-made specimens exhibited tensile residual stresses of up to 400 MPa in the surface area. HP-XRD analysis revealed a stress-induced lattice distortion, interpreted as a transitional state between the β-phase and α”-phase. In contrast, the EB-PBF-made specimens showed no significant residual stress and had an undistorted β-phase coexisting with the hexagonal α-phase caused by elemental partitioning. This study provides new insights into the previously neglected effects of L-PBF and EB-PBF in unstable β-type titanium alloys.

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A paper on the expression of anisotropic/isotropic mechanical functions by site-dependent control of shape using laser additive manufacturing has been published in "Crystals" as an open access article.

Naoko Ikeo#, *, Hidetsugu Fukuda#, Aira Matsugaki*, Toru Inoue, Ai Serizawa, Tadaaki Matsuzaka, Takuya Ishimoto, Ryosuke Ozasa, Ozkan Gokcekaya, Takayoshi Nakano*:
3D puzzle in cube pattern for anisotropic/isotropic mechanical control of structure fabricated by metal additive manufacturing,
Crystals, 11(8), (2021), 11(8), 959; 1-10.
https://doi.org/10.3390/cryst11080959.
#: These authors contributed equally to this work.
*: Corresponding author

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Abstract
Metal additive manufacturing is a powerful tool for providing the desired functional performance through a three-dimensional (3D) structural design. Among the material functions, anisotropic mechanical properties are indispensable for enabling the capabilities of structural materials for living tissues. For biomedical materials to replace bone function, it is necessary to provide an anisotropic mechanical property that mimics that of bones. For desired control of the mechanical performance of the materials, we propose a novel 3D puzzle structure with cube-shaped parts comprising 27 (3 × 3 × 3) unit compartments. We designed and fabricated a Co–Cr–Mo composite structure through spatial control of the positional arrangement of powder/solid parts using the laser powder bed fusion (L-PBF) method. The mechanical function of the fabricated structure can be predicted using the rule of mixtures based on the arrangement pattern of each part. The solid parts in the cubic structure were obtained by melting and solidifying the metal powder with a laser, while the powder parts were obtained through the remaining nonmelted powders inside the structure. This is the first report to achieve an innovative material design that can provide an anisotropic Young’s modulus by arranging the powder and solid parts using additive manufacturing technology.

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Our findings on the effect of gas atmosphere on sputtering during metal AM was published as an open access article in Materials Transactions.

Hiroki Amano, Yusuke Yamaguchi, Takuya Ishimoto, Takayoshi Nakano*:
Reduction of Spatter Generation Using Atmospheric Gas in Laser Powder Bed Fusion of Ti–6Al–4V,
Materials Transactions, 62, (2021), 1225-1230.
https://doi.org/10.2320/matertrans.MT-M2021059

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Abstract
Laser powder bed fusion (LPBF), a typical additive manufacturing (AM) process, is a promising approach that enables high-accuracy manufacturing of arbitrary structures; therefore, it has been utilized in the aerospace and medical fields. However, several unexplained phenomena significantly affect the quality of fabricated components. In particular, it has been reported that the generation of spatters adversely affects the stability of fabrication process and degrades the performance of the fabricated components. To realize high-quality components, it is essential to suppress the generation of spatters. Thus far, the suppression of spatter generation has been attempted based on the process parameters; however, this has not been adequately discussed in terms of the fabrication atmosphere. Therefore, in this study, we focused on the fabrication atmosphere and investigated spatter generation using gas with different physical properties rather than conventionally used argon. It was observed that the spatter generation during the fabrication of the Ti–6Al–4V alloy could be significantly suppressed by changing the atmospheric gas, even under constant LPBF process parameters. We proved that the fabrication atmosphere is an important factor to be considered, apart from the process parameters, in AM technology.

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A study on microstructure control of stainless steel by electron beam additive manufacturing was published in Crystals as open access.

Yuichiro Miyata, Masayuki Okugawa*, Yuichiro Koizumi*, Takayoshi Nakano:
Inverse columnar-equiaxed transition in 304 and 316L stainless steels melt by electron-beam for additive manufacturing,
Crystals, 11 (8), (2021), 856: 1-13.
https://doi.org/10.3390/cryst11080856

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Abstract

According to Hunt’s columnar-to-equiaxed transition (CET) criterion, which is generally accepted, a high-temperature gradient (G) in the solidification front is preferable to a low G for forming columnar grains. Here, we report the opposite tendency found in the solidification microstructure of stainless steels partially melted by scanning electron beam for powder bed fusion (PBF)-type additive manufacturing. Equiaxed grains were observed more frequently in the region of high G rather than in the region of low G, contrary to the trend of the CET criterion. Computational thermal-fluid dynamics (CtFD) simulation has revealed that the fluid velocity is significantly higher in the case of smaller melt regions. The G on the solidification front of a small melt pool tends to be high, but at the same, the temperature gradient along the melt pool surface also tends to be high. The high melt surface temperature gradient can enhance Marangoni flow, which can apparently reverse the trend of equiaxed grain formation.

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A paper on the improvement of tensile properties of TiAl alloy containing β-phase by cell precipitation using electron beam plastic forming (EBPBF) has been published in "Crystals" as an open access paper.

Ken Cho, Hirotaka Odo, Keisuke Okamoto, Hiroyuki Y. Yasuda*, Hirotoyo Nakashima, Masao Takeyama, Takayoshi Nakano:
Improving the tensile properties of additively manufactured β-containing TiAl alloys via microstructure control focusing on cellular precipitation reaction,
Crystals, 11 (7), (2021), 809; 1-13.
https://doi.org/10.3390/cryst11070809 

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Abstract
The effect of a two-step heat treatment on the microstructure and high-temperature tensile properties of β-containing Ti-44Al-4Cr (at%) alloys fabricated by electron beam powder bed fusion were examined by focusing on the morphology of α2/γ lamellar grains and β/γ cells precipitated at the lamellar grain boundaries by a cellular precipitation reaction. The alloys subjected to the first heat treatment step at 1573 K in the α + β two-phase region exhibit a non-equilibrium microstructure consisting of the α2/γ lamellar grains with a fine lamellar spacing and a β/γ duplex structure located at the grain boundaries. In the second step of heat treatment, i.e., aging at 1273 K in the β + γ two-phase region, the β/γ cells are discontinuously precipitated from the lamellar grain boundaries due to excess Cr supersaturation in the lamellae. The volume fraction of the cells and lamellar spacing increase with increasing aging time and affect the tensile properties of the alloys. The aged alloys exhibit higher strength and comparable elongation at 1023 K when compared to the as-built alloys. The strength of these alloys is strongly dependent on the volume fraction and lamellar spacing of the α2/γ lamellae. In addition, the morphology of the β/γ cells. is also an important factor controlling the fracture mode and ductility of these alloys.

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A study on quantitative comparison of crystallographic features and residual stresses of Ti-6Al-4V fabricated by metal 3D printing (L-PBF and EB-PBF) was published as an open access article in Crystals.

Aya Takase*, Takuya Ishimoto, Naotaka Morita, Naoko Ikeo, Takayoshi Nakano*
Comparison of phase characteristics and residual stresses in Ti-6Al-4V alloy manufactured by laser powder bed fusion (L-PBF) and electron beam powder bed fusion (EB-PBF) techniques.
Crystals, 11(7), (2021), 796; 1-17.
https://doi.org/10.3390/cryst11070796
*: Corresponding author

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Abstract
Ti-6Al-4V alloy fabricated by laser powder bed fusion (L-PBF) and electron beam powder bed fusion (EB-PBF) techniques have been studied for applications ranging from medicine to aviation. The fabrication technique is often selected based on the part size and fabrication speed, while less attention is paid to the differences in the physicochemical properties. Especially, the relationship between the evolution of α, α’, and β phases in as-grown parts and the fabrication techniques is unclear. This work systematically and quantitatively investigates how L-PBF and EB-PBF and their process parameters affect the phase evolution of Ti-6Al-4V and residual stresses in the final parts. This is the first report demonstrating the correlations among measured parameters, indicating the lattice strain reduces, and c/a increases, shifting from an α’ to α+β or α structure as the crystallite size of the α or α’ phase increases. The experimental results combined with heat-transfer simulation indicate the cooling rate near the β transus temperature dictates the resulting phase characteristics, whereas the residual stress depends on the cooling rate immediately below the solidification temperature. This study provides new insights into the previously unknown differences in the α, α’, and β phase evolution between L-PBF and EB-PBF and their process parameters.

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Our joint research with Narushima Lab. of Tohoku University on the improvement of properties of CO-Cr-W-Ni stent alloys by adding Mn has been published in Metallurgical and Materials Transactions A as an open access article.

Soh Yanagihara*, Kosuke Ueki, Kyosuke Ueda , Masaaki Nakai, Takayoshi Nakano, Takayuki Narushima:
Development of low-yield stress Co-Cr-W-Ni alloy by adding 6mass% Mn for balloon-expandable stents,
Metallurgical and Materials Transactions A, (2021), in press.
https://doi.org/10.1007/s11661-021-06374-7

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Abstract
This is the first report presenting the development of a Co–Cr–W–Ni–Mn alloy by adding 6 mass pct Mn to ASTM F90 Co–20Cr–15W–10Ni (CCWN, mass pct) alloy for use as balloon-expandable stents with an excellent balance of mechanical properties and corrosion resistance. The effects of Mn addition on the microstructures as well as the mechanical and corrosion properties were investigated after hot forging, solution treatment, swaging, and static recrystallization. The Mn-added alloy with a grain size of ~ 20 µm (recrystallization condition: 1523 K, 150 seconds) exhibited an ultimate tensile strength of 1131 MPa, 0.2 pct proof stress of 535 MPa, and plastic elongation of 66 pct. Additionally, it exhibited higher ductility and lower yield stress while maintaining high strength compared to the ASTM F90 CCWN alloy. The formation of intersecting stacking faults was suppressed by increasing the stacking fault energy (SFE) with Mn addition, resulting in a lower yield stress. The low-yield stress is effective in suppressing stent recoil. In addition, strain-induced martensitic transformation during plastic deformation was suppressed by increasing the SFE, thereby improving the ductility. The Mn-added alloys also exhibited good corrosion resistance, similar to the ASTM F90 CCWN alloy. Mn-added Co–Cr–W–Ni alloys are suitable for use as balloon-expandable stents.

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A study of new insights into the correlation between crystallographic symmetry and crystal orientation formed by metal 3D printing has been published as an open access paper in Scripta Materialia.

Koji Hagihara#, Takuya Ishimoto#, Masahiro Suzuki, Ryosuke Ozasa, Aira Matsugaki, Pan Wang, Takayoshi Nakano∗
Factor which governs the feature of texture developed during additive manufacturing; clarified from the study on hexagonal C40-NbSi2, Scripta Materialia, 203, (2021), 114111; 1-6.
https://doi.org/10.1016/j.scriptamat.2021.114111
#: The authors equally contributed to this study.
*: Corresponding author

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Abstract
C40-NbSi2 with a hexagonal unit cell is focused as a high-temperature structural material. We first at- tempted the fabrication of the bulk C40-NbSi2 products via selective laser melting (SLM) in additive manufacturing (AM) process. Strong crystallographic texture control wherein <0001> was parallel to the building direction, i.e. development of the so-called basal fiber texture, was achieved in this study. The texture developed in products does not largely vary by changing the scanning strategy, unlike the textures of C11b -MoSi2 with a tetragonal unit cell and a β-Ti alloy with a cubic unit cell. A comparison of these results led us to the conclusion that crystal symmetry, i.e., the multiplicity of the preferential crystal growth direction, is one of the primary factors that governs the features of the textures developed in AM-built materials.

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A paper on the antimicrobial effect of Ti alloy using Cu was published in Materials Transactions.

Qiang Li, Jinshuai Yang, Junjie Li, Ran Zhang, Masaaki Nakai, Mitsuo Niinomi, Takayoshi Nakano:
Antibacterial Cu-doped calcium phosphate coating on pure titanium,
Materials Transactions, 62 [7], (2021), 1052-1055.
http://doi.org/10.2320/matertrans.MT-M2021005

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Abstract
Cu-doped amorphous calcium phosphate (ACP) coatings were fabricated on the surface of pure titanium (Ti) by electrochemical deposition at initial electrolyte temperatures of 35, 45, and 55 °C. The antibacterial activities of the coatings were then evaluated by the plate counting method using Escherichia coli as the indicator. The Cu concentrations on the surfaces of samples are increased from 6.90 to 15.05 mass% as initial electrolyte temperature is increased from 35 to 55 °C. The Cu-doped ACP coatings show that they can fully inhibit the growth of E. coli.

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A study on the peculiar microstructure and mechanical study of γ-TiAl intermetallic compound with β-phase formed by electron beam metal 3D printing has been published in Additive Manufacturing in open access.

Ken Cho, Hajime Kawabata, Tatsuhiro Hayashi, Hiroyuki Y. Yasuda*, Hirotoyo Nakashima, Masao Takeyama, Takayoshi Nakano:
Peculiar microstructural evolution and tensile properties of β-containing γ-TiAl alloys fabricated by electron beam melting,
Additive Manufacturing, (2021), 102091.
https://doi.org/10.1016/j.addma.2021.102091

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ABSTRACT
The microstructure and tensile properties of β-containing Ti-44Al-4Cr alloy rods additively manufactured by electron beam melting (EBM) process were examined as a function of input energy density determined by the processing parameters. To the best of our knowledge, this is the first report to demonstrate that two types of fine microstructures have been obtained in the β-containing γ-TiAl alloys by varying the energy density during the EBM process. A uniform α2/β/γ mixed structure containing an α2/γ lamellar region and a β/γ dual-phase region is formed at high energy density conditions. On the other hand, a lower energy density leads to the formation of a peculiar layered microstructure perpendicular to the building direction, consisting of a ultrafine α2/γ lamellar grain layer and a α2/β/γ mixed structure layer. The difference in the microstructures originates from the difference in the solidification microstructure and the temperature distribution from the melt pool, which are dependent on the energy density. Furthermore, it was found that the strength of the alloys is closely related to the volume fractions of the β phase and the ultrafine α2/γ lamellar grains which originates from the massive α grains formed by rapid cooling under low energy density conditions. The alloys with high amounts of these peculiar microstructures exhibit high strength comparable to and higher than the conventional β-containing γ-TiAl at room temperature and 1023 K, respectively.

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A study on the peculiar microstructure and mechanical study of γ-TiAl intermetallic compound with β-phase formed by electron beam metal 3D printing has been published in Additive Manufacturing in open access.

Ken Cho, Hajime Kawabata, Tatsuhiro Hayashi, Hiroyuki Y. Yasuda*, Hirotoyo Nakashima, Masao Takeyama, Takayoshi Nakano:
Peculiar microstructural evolution and tensile properties of β-containing γ-TiAl alloys fabricated by electron beam melting,
Additive Manufacturing, 46, (2021), 102091; 1-12.
https://doi.org/10.1016/j.addma.2021.102091

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ABSTRACT
The microstructure and tensile properties of β-containing Ti-44Al-4Cr alloy rods additively manufactured by electron beam melting (EBM) process were examined as a function of input energy density determined by the processing parameters. To the best of our knowledge, this is the first report to demonstrate that two types of fine microstructures have been obtained in the β-containing γ-TiAl alloys by varying the energy density during the EBM process. A uniform α2/β/γ mixed structure containing an α2/γ lamellar region and a β/γ dual-phase region is formed at high energy density conditions. On the other hand, a lower energy density leads to the formation of a peculiar layered microstructure perpendicular to the building direction, consisting of a ultrafine α2/γ lamellar grain layer and a α2/β/γ mixed structure layer. The difference in the microstructures originates from the difference in the solidification microstructure and the temperature distribution from the melt pool, which are dependent on the energy density. Furthermore, it was found that the strength of the alloys is closely related to the volume fractions of the β phase and the ultrafine α2/γ lamellar grains which originates from the massive α grains formed by rapid cooling under low energy density conditions. The alloys with high amounts of these peculiar microstructures exhibit high strength comparable to and higher than the conventional β-containing γ-TiAl at room temperature and 1023 K, respectively.

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A paper reported the phenomenon that the orientation of human iPSC-osteoblasts is strongly oriented through the adhesion group by an oriented collagen scaffold material has been published in the International Journal of Molecular Sciences as an openaccess

Ryosuke Ozasa#, Aira Matsugaki#, Tadaaki Matsuzaka, Takuya Ishimoto, Yun Hui-suk, Takayoshi Nakano*:
Superior alignment of human iPSC-osteoblasts associated with focal adhesion formation stimulated by oriented collagen scaffold,
International Journal of Molecular Sciences, 22, (2021), 6232; 1-11.
https://doi.org/10.3390/ijms22126232
#These authors contributed equally to this work.
*Corresponding author

Click here for this paper.

Abstract:
Human-induced pluripotent stem cells (hiPSCs) can be applied in patient-specific cell therapy to regenerate lost tissue or organ function. Anisotropic control of the structural organization in the newly generated bone matrix is pivotal for functional reconstruction during bone tissue regeneration. Recently, we revealed that hiPSC-derived osteoblasts (hiPSC-Obs) exhibit preferential alignment and organize in highly ordered bone matrices along a bone-mimetic collagen scaffold, indicating their critical role in regulating the unidirectional cellular arrangement, as well as the structural organization of regenerated bone tissue. However, it remains unclear how hiPSCs exhibit the cell properties required for oriented tissue construction. The present study aimed to characterize the properties of hiPSCs-Obs and those of their focal adhesions (FAs), which mediate the structural relationship between cells and the matrix. Our in vitro anisotropic cell culture system revealed the superior adhesion behavior of hiPSC-Obs, which exhibited accelerated cell proliferation and better cell alignment along the collagen axis compared to normal human osteoblasts. Notably, the oriented collagen scaffold stimulated FA formation along the scaffold collagen orientation. This is the first report of the superior cell adhesion behavior of hiPSC-Obs associated with the promotion of FA assembly along an anisotropic scaffold. These findings suggest a promising role for hiPSCs in enabling anisotropic bone microstructural regeneration.

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The winners of the Japan Institute of Metals Fall Awards were unofficially announced, and Nakano Lab received three awards.

〇Aira Matsugaki et al: The 18th Murakami Encouragement Award,
The Japan Institute of Metals and Materials, September 14, 2021

〇Taketsugu Nagase, Mitsuhiro Toshiro, Takayoshi Nakano: 69th Best Paper Award, Development of Co-Cr-Mo-Fe-Mn-W and Co-Cr-Mo-Fe
For : Development of Co-Cr-Mo-Fe-Mn-W and Co-Cr-Mo-Fe-Mn-W-Ag High-Entropy Alloys Based on Co-Cr-Mo Alloys.
The Japan Institute of Metals and Materials, September 14, 2021

〇Aira Matsugaki and T. Nakano: The 11th Matelia Award, for the
For : Induction of Bone Functionalization Based on the Mechanism of Cell and Bone Matrix Orientation
The Japan Institute of Metals and Materials, September 14, 2021

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A paper on antibacterial properties and osteoblast adhesion of Ag-doped defective apatite was published as open access in Crystals (MDPI).

Ozkan Gokcekaya, Celaletdin Ergun*, Thomas J. Webster, Abdurrahman Bahadir, Kyosuke Ueda, Takayuki Narushima, Takayoshi Nakano:
Effect of precursor deficiency induced Ca/P ratio on antibacterial and osteoblast adhesion properties of Ag-incorporated hydroxyapatite: Reducing Ag toxicity,
Materials, 14, (2021), 3158; 1-18.
https://doi.org/10.3390/ma14123158
*: Corresponding author

Click here for this paper.

Abstract: Ag-containing hydroxyapatite (HA) can reduce risks associated with bacterial infections which may eventually require additional surgical operations to retrieve a failed implant. The biological properties of HA in such applications are strongly affected by its composition in terms of dopants as well as Ca/P stoichiometry, which can be easily controlled by altering processing parameters, such as precursor concentrations. The objective of this in vitro study was to understand the effect of variations in HA precursor solutions on antibacterial properties against Escherichia coli (E. coli) and for promoting osteoblast (bone-forming cell) adhesion on Ag incorporated HA (AgHA) which has not yet been investigated. For this, two groups of AgHAs were synthesized via a precipitation method by adjusting precursor reactants with a stoichiometric value of 1.67, being either (Ca + Ag)/P (Ca-deficient) or Ca/(P + Ag) (P-deficient), and were characterized by XRD, FTIR, and SEM1EDS. Results showed that Ag+ incorporated into the Ca2+ sites was associated with a corresponding OH− vacancy. Additional incorporation of CO32− into PO43− sites occurred specifically for the P-deficient AgHAs. While antibacterial properties increased, osteoblast adhesion decreased with increasing Ag content for the Ca-deficient AgHAs, as anticipated. In contrast, significant antibacterial properties with good osteoblast behavior were observed on the P-deficient AgHAs even with a lower Ag content, owing to carbonated HA. Thus, this showed that by synthesizing AgHA using P-deficient precursors with carbonate substitution, one can keep the antibacterial properties of Ag in HA while reducing its toxic effect on osteoblasts.

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The journal Additive Manufacturing (Elsevier) has published an open access paper showing that the improvement in corrosion resistance of stainless steel (SUS316L) by metal 3D printing is not affected by microstructure and the associated dislocation densit

Yusuke Tsutumi*, Takuya Ishimoto, Tastuya Oishi, Tomoyo Manaka, Peng Chen, Maki Ashida, Kotaro Doi, Hideki Katayama, Takao Hanawa, Takayoshi Nakano*:
Crystallographic texture- and grain boundary density-independent improvement of corrosion resistance in austenitic 316L stainless steel fabricated via laser powder bed fusion,
Additive manufacturing, (2021), 102066; 1-9.
https://doi.org/10.1016/j.addma.2021.102066
*: Corresponding author

Click here for this paper.

Abstract
Improvement of corrosion resistance of austenitic 316 L stainless steel via laser powder bed fusion (LPBF) is currently a prominent research topic; however, the effects of crystallographic texture and the related grain boundary density on the corrosion resistance of LPBF-fabricated parts have not been elucidated. For biomedical applications, crystallographic texture control from a single crystalline-like to randomly oriented polycrystalline microstructure is highly attractive for optimizing the mechanical properties (particularly the Young’s modulus) of implants. An investigation of the impacts of crystallographic planes and grain boundaries exposed to the biological environment on corrosion behavior is necessary. 316 L stainless steels with different crystallographic textures and grain boundary densities were successfully fabricated via LPBF. The corrosion resistances of the LPBF-fabricated specimens were comprehensively assessed by anodic polarization, dissolution, and crevice corrosion repassivation tests. The LPBF-fabricated specimens showed extremely high pitting potentials in the physiological saline compared with the commercially available counterparts, and importantly, excellent pitting corrosion resistance was observed irrespective of the crystallographic planes and grain boundary density exposed. Moreover, the LPBF-fabricated specimens did not show metastable pitting corrosion even in an accelerated test using an acid solution. The repassivation behavior of the specimens was not affected by LPBF. Such a drastic improvement in the corrosion resistances of the LPBF-fabricated specimens might be attributed to suppression of inclusion coarsening owing to the rapid cooling rate during solidification in LPBF. By using LPBF, the desired crystallographic texture can be introduced based on the desired mechanical properties without concern for corrosiveness.

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The results of a joint research with Professor Mikako Hayashi at Osaka University Graduate School of Dentistry have been published as an open access article in Dental Materials Journal.

Kyoko Yagi, Reo Uemura, Hiroko Yamamoto, Takuya Ishimoto, Katsuaki Naito, Shousaku Itoh, Yasuhiro Matsuda, Katsushi Okuyama, Takayoshi Nakano, Mikako Hayashi:
In-air micro-proton-induced X-ray/gamma-ray emission analysis of the acid resistance of root dentin after applying fluoride-containing materials incorporating calcium,
Dental Materials Journal, (2021), online.
https://doi.org/10.4012/dmj.2020-273

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Abstract
This study employed an in-air micro-proton-induced X-ray/gamma-ray emission system to assess the effectiveness of fluoride-containing materials (FCMs) incorporating calcium in preventing root caries. Dentin surfaces of human third molars were coated with one of three FCMs: fluoride-releasing glass-ionomer cement (F7) and experimental materials in which half (P1) or all (P2) of the strontium in F7 was replaced with calcium. Dentin without FCM coating served as the control. Specimens were immersed in saline at 37°C for 1 month, sectioned, and then demineralized. Calcium loss after demineralization was lower in the Ca-substituted groups than in the Ca-unsubstituted groups (p<0.05). Calcium loss was negatively correlated with fluoride uptake (p<0.01). In the F7, P1, and P2 groups, the retraction of the dentin surface was significantly suppressed as compared with the control group. FCMs incorporating calcium improved the acid resistance of root dentin and could help prevent root caries.

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A paper quantitatively demonstrating that the shape and arrangement of osteocyte lacunae are determinants of bone orientation has been published as an open access article in Calcified Tissue International. This is a joint research with Prof. Ueoka of Okay

Takuya Ishimoto, Keita Kawahara, Aira Matsugaki, Hiroshi Kamioka, Takayoshi Nakano*:
Quantitative Evaluation of Osteocyte Morphology and Bone Anisotropic Extracellular Matrix in Rat Femur,
Calcified Tissue International, (2021), online.
https://doi.org/10.1007/s00223-021-00852-1

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Abstract
Osteocytes are believed to play a crucial role in mechanosensation and mechanotransduction which are important for maintenance of mechanical integrity of bone. Recent investigations have revealed that the preferential orientation of bone extracellular matrix (ECM) mainly composed of collagen fibers and apatite crystallites is one of the important determinants of bone mechanical integrity. However, the relationship between osteocytes and ECM orientation remains unclear. In this study, the association between ECM orientation and anisotropy in the osteocyte lacuno-canalicular system, which is thought to be optimized along with the mechanical stimuli, was investigated using male rat femur. The degree of ECM orientation along the femur longitudinal axis was significantly and positively correlated with the anisotropic features of the osteocyte lacunae and canaliculi. At the femur middiaphysis, there are the osteocytes with lacunae that highly aligned along the bone long axis (principal stress direction) and canaliculi that preferentially extended perpendicular to the bone long axis, and the highest degree of apatite c-axis orientation along the bone long axis was shown. Based on these data, we propose a model in which osteocytes can change their lacuno-canalicular architecture depending on the mechanical environment so that they can become more susceptible to mechanical stim

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Acta Materialia has published an open access article on unique tissues freely formed with Inconel718 by laser metal 3D printing.

Ozkan Gokcekaya#, Takuya Ishimoto#, Shinya Hibino, Jumpei Yasutomi, Takayuki Narushima, Takayoshi Nakano*:
Unique crystallographic texture formation in Inconel 718 by laser powder bed fusion and its effect on mechanical anisotropy,
Acta Materialia, 212, (2021), 116876; 1-12..
https://doi.org/10.1016/j.actamat.2021.116876
#: The authors equally contribute to this article.

Click here for this paper.

Abstract

Additive manufacturing offers an exclusive way of anisotropic microstructure control with a high degree of freedom regarding variation in process parameters. This study demonstrates a unique texture formation in Inconel 718 (IN718) using a bidirectional laser scan in a laser powder bed fusion (LPBF) process for tailoring the mechanical properties. We developed three distinctive textures in IN718 using LPBF: a single-crystal-like microstructure (SCM) with a <110> orientation in the build direction (BD), crystallographic lamellar microstructure (CLM) with a <110>-oriented main layer and <100>-oriented sub-layer in the BD, and polycrystalline with a weak orientation. The microstructure observations and finite element simulations showed that the texture evolution of the SCM and CLM was dominated by the melt-pool shape and related heat-flow direction. The specimen with CLM exhibited a simultaneous improvement in strength and ductility owing to the stress-transfer coefficient between the <110>-oriented main and <100>-oriented sub-grains, showing superior mechanical properties compared to cast-IN718. This behavior is largely attributed to the presence of the boundary between the main and sub-layers (crystallographic grain boundary) lying parallel to the BD uniquely formed under the LPBF process. Furthermore, the strength–ductility balance of the part with the CLM can be controlled by changing the stress-transfer coefficient and the Schmidt factor through an alteration of the loading axis. Control of the crystallographic texture, including the CLM formation, is beneficial for tailoring and improving the mechanical performance of the structural materials, which can be a promising methodology

Keywords
Laser powder bed fusion, Inconel 718, Crystallographic texture, Lamellae, Mechanical anisotropy

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Our research on the mechanism and stability of crystallographic orientation relationships formed by metal AM, as well as the possibility of seeding single crystals, has been published as an open access paper in Additive Manufacturing.

Takuya Ishimotoǂ, Koji Hagiharaǂ, Kenta Hisamoto, Takayoshi Nakano*:
Stability of crystallographic texture in laser powder bed fusion: Understanding the competition of crystal growth using a single crystalline seed,
Additive Manufacturing, 43, (2021), 102004; 1-11.
https://doi.org/10.1016/j.addma.2021.102004
ǂ These authors contributed equally to this work.

Click here for this paper.

Abstract
In metal additive manufacturing, crystallographic orientation control is a promising method for tailoring the functions of metallic parts. However, despite its importance in the fabrication of texture-controlled functional parts, the stability of the crystallographic texture is not widely discussed. Herein, the crystallographic texture stability under laser powder bed fusion was investigated. Two methodologies were employed. One is that a laser scanning strategy was alternately changed for a specific number of layers. The other is a “seeding” experiment in which single-crystalline substrates with controlled crystallographic orientations in the building (z-) direction and the xy-plane (perpendicular to the building direction) were used as the starting substrate. The transient zone width, where the crystallographic orientation was inherited from the layer beneath, was analyzed to evaluate the texture stability. The crystallographic direction of the seed within the xy-plane, rather than the building direction, determined the transient zone width, i.e., the texture stability. In particular, the texture in the newly deposited portion was stable when the laser scanning direction matched the <100> orientation in the underneath layer, otherwise the crystal orientation switched rapidly, such that the <100> orientation was parallel to the scanning direction. Interestingly, the crystallographic orientation along the building direction in the underneath layer hardly impacted the stability of the texture. Therefore, for the first time, it has been clarified that the <100> orientation in the scanning direction, rather than the building direction, was preferentially stabilized, whereas the orientation in the other directions secondary stabilized.

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Our paper on the discovery of lattice deformation due to residual strain in AM-formed β-type titanium alloy has been published as an open access paper in Scripta Materialia.

Aya Takase*, Takuya Ishimoto, Ryoya Suganuma, Takayoshi Nakano*:
Lattice distortion in selective laser melting (SLM)-manufactured unstable β-type Ti-15Mo-5Zr-3Al alloy analyzed by high-precision X-ray diffractometry,
Scripta Materialia, 201, (2021), 113953; 1-6.
https://doi.org/10.1016/j.scriptamat.2021.113953

Abstract
A peculiar lattice distortion in a selective laser melting (SLM)-manufactured unstable β-type Ti-15Mo-5Zr-3Al was observed for the first time, through high-precision X-ray diffraction (XRD) analyses. After SLM, Ti-15Mo-5Zr-3Al exhibited a body-centered-tetragonal structure instead of a body-centered-cubic structure; the c-axis was 0.63% shorter than the a-axis. The XRD analyses also revealed tensile residual stresses of 210 ± 12 MPa at the specimen surface. A numerical simulation indicated rapid cooling during the SLM, which could have caused the residual stresses. A comparison of the partially stress-released SLM specimen and an electron beam melting-manufactured specimen with negligible residual stress suggested that the residual stress caused by the rapid cooling in SLM induced the lattice distortion. This finding is not consistent with the previous understanding that residual stress changes the lattice parameter without lattice distortion. This study provides new insight into lattice distortion generated by a combination of SLM-specific ultrarapid cooling and unstable phases.

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A joint research paper with Keio University School of Medicine and others on the discovery of auditory osteoblasts and their functionalization through bone density and apatite orientation was published as an open access paper in Journal of Bone and Minera

Yukiko Kuroda, Katsuhiro Kawaai, Naoya Hatano, Yanlin Wu, Hidekazu Takano, Atsushi Momose, Takuya Ishimoto, Takayoshi Nakano, Paul Roschger, Stéphane Blouin, Koichi Matsuo*:
Hypermineralization of hearing-related bones by a specific osteoblast subtype,
Journal of Bone and Mineral Research, (2021)
https://doi.org/10.1002/jbmr.4320

Click here for this paper.

Abstract
Auditory ossicles in the middle ear and bony labyrinth of the inner ear are highly mineralized in adult mammals. Cellular mechanisms underlying formation of dense bone during development are unknown. Here, we found that osteoblast‐like cells synthesizing highly mineralized hearing‐related bones produce both type I and type II collagens as the bone matrix, while conventional osteoblasts and chondrocytes primarily produce type I and type II collagens, respectively. Furthermore, these osteoblast‐like cells were not labeled in a “conventional osteoblast”‐specific green fluorescent protein (GFP) mouse line. Type II collagen‐producing osteoblast‐like cells were not chondrocytes as they express osteocalcin, localize along alizarin‐labeled osteoid, and form osteocyte lacunae and canaliculi, as do conventional osteoblasts. Auditory ossicles and the bony labyrinth exhibit not only higher bone matrix mineralization but a higher degree of apatite orientation than do long bones. Therefore, we conclude that these type II collagen‐producing hypermineralizing osteoblasts (termed here auditory osteoblasts) represent a new osteoblast subtype.

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Dr. Nakano has been appointed as the 70th President of the Japan Institute of Metals and Materials. His term of office is for two years.

Dr. Nakano has been appointed as the 70th President of the Japan Institute of Metals and Materials. His term of office is for two years.

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Our paper on the discovery of lattice deformation due to residual strain in AM-formed β-titanium alloys has been accepted by Scripta Materialia. The paper will be published as an open access article.

Aya Takase*, Takuya Ishimoto, Ryoya Suganuma, Takayoshi Nakano*:
Lattice distortion in selective laser melting (SLM)-manufactured unstable β-type Ti-15Mo-5Zr-3Al alloy analyzed by high-precision X-ray diffractometry,
Scripta Materialia, (2021), in press.

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In collaboration with Tokyo Dental University, our paper on botulinum-induced changes in bone quality was published in the Journal of Hard Tissue Biology as open access.

Gaku Kusaba, Satoru Matsunaga, Kei Kitamura, Masaaki Kasahara, Yoshiaki Shimoo, Shinichi Abe, Takayoshi Nakano, Takuya Ishimoto, Atsuhiko Hikita, Kunihiko Nojima, Yasushi Nishii:
Micro/nanostructural Characteristic Changes in the Mandibles of Rats after Injection of Botulinum Neurotoxin, Journal of Hard Tissue Biology, 30(2), (2021), 183-192.
DOI: 10.2485/jhtb.30.183

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Abstract
Our objective was to perform a quantitative evaluation of changes in the micro/nanostructural characteristics of entheses in rats with reduced masticatory muscle functional pressure, with the aim of elucidating the mechanism whereby masticatory muscle functional pressure contributes to growth and development of the mandible from a biomechanical perspective. Male Wister rats aged 4, 11, 18 and 25 weeks were divided into a Botox group injected with a botulinum toxin serotype A formulation to reduce muscle function (BTX) and a control group (CTRL). They were euthanized 6 weeks later and bone quality at the masseter insertion at the mandibular was analyzed. In the BTX group, the number of fibrous chondrocytes at entheses was significantly lower than in the CTRL group at all ages. The diameter of collagen fiber bundles in rats in the BTX group injected with BoNT/A during their growth phase was significantly smaller than that of rats in the CTRL group. In the mandibles of rats in the CTRL group the preferential alignment was consistent with the orientations of the muscle and tendon, but in growing rats treated with BTX, it was less closely aligned with the orientations of the muscle and tendon.

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A paper on tissue control simulation in AM was published as open access in Materials Transactions.

Jun Kubo, Yuichiro Koizumi, Takuya Ishimoto and Takayoshi Nakano:
Modified Cellular Automaton Simulation of Metal Additive Manufacturing,
Materials Transactions, (2021) 103–109.

Click here for this paper

Abstract
Metal additive manufacturing (AM) technologies are attracting attentions not only as a fabrication process of complicated three-dimensional parts but also as microstructure controlling processes. In powder bed fusion (PBF)-type AM, crystallographic texture can be controlled by scanning strategies of energy beam. To optimize microstructures, computer simulations for predicting microstructures play very important roles. In this work, we have developed simulation programs to explain the mechanism of the crystal orientation control. First, we simulated the shape of melt pool by analyzing the heat transfer using apparent heat conductivity when the penetration of laser beam through keyholes was taken into consideration because of the evaporation and accompanying convections. It was assumed that the primary crystal growth direction can be determined by the temperature gradient, and the crystals grow keeping the growth direction as generally recognized. The shapes of simulated melt pools agree well with experimental observations. The modified cellular automaton simulations successfully reproduced two typical textures with different preferential orientations along the building directions of 〈100〉 and 〈110〉 when the bidirectional scanning with and without a rotation of 90°, respectively, was accomplished between the layers.

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A new mechanism for the strengthening of LPSO layers by Mg alloys has been published in Acta Materialia as an open access article.

Koji Hagihara*, Ryohei Ueyama, Michiaki Yamasaki, Yoshihito Kawamura, Takayoshi Nakano:
Surprising increase in yield stress of Mg single crystal using long-period stacking ordered nanoplates,
Acta Materialia, (2021), 116797.
https://doi.org/10.1016/j.actamat.2021.116797

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Abstract
Mg–Zn–Y ternary alloys containing the long-period stacking ordered (LPSO) phase exhibit superior mechanical properties. This is believed to be originating from the LPSO phase acting as the strengthening phase. However, we first clarify that the mechanical properties of the matrix Mg solid solution in the Mg/LPSO two-phase alloy are significantly different from those of pure Mg. The yield stress of a Mg99.2Zn0.2Y0.6 single crystal (matrix Mg solid solution) is almost the same as that of an LPSO single-phase alloy. This is ascribed to the formation of thin stacking-fault-like defects, named “LPSO nanoplate”. In Mg99.2Zn0.2Y0.6, kink-band formation is induced in the same manner as that in the LPSO phase in deformation, resulting in high strength accompanied with increased ductility. Our results suggest that the strengthening mechanism of the Mg/LPSO two-phase alloy must be reconsidered depending on the microstructure. Furthermore, the results suggest that new ultrahigh-strength Mg alloys, which have much lower Zn and Y contents but the mechanical properties are comparable or superior than the present Mg/LPSO two-phase alloys, are expected to be developed via the appropriate control of LPSO nanoplate microstructures.

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A study on the mechanism of improved wear properties of biological Co-Cr-Mo alloy single crystals was published as an open access paper in Wear magazine (Elsevier).

Takayoshi Nakano*, Koji Hagihara, Ana R. Ribeiro, Yusuke Fujiia, Tsubasa Todo, Ryo Fukushima, Luís Augusto Rocha:Orientation dependence of the wear resistance in the Co–Cr–Mo single crystal, Wear 478–479 (2021) 203758.
https://doi.org/10.1016/j.wear.2021.203758

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Abstract
This is the report clarifying the orientation dependence of the wear behavior of Co–Cr–Mo alloy. The wear resistance of the Co–Cr–Mo alloy with face-centered cubic (fcc) structure was found to be higher on the planes in order of {110}, {001} and {111}. Quantitatively, the wear resistance on {110} is 1.5 times larger than that on {111}. The tendency showed in coincident with the orientation dependence of the surface hardness, as empirically suggested. However, we additionally found in the observation of the worn surface in the fcc-single crystals that the volume fraction of the hexagonal close-packed (hcp)-phase, which was formed as the strain-induced martensite during the wear test, was larger in the same order of the wear resistance. The variation in formation frequency of the hcp-phase during the wear test can be explained by focusing on the Schmid factor along the resultant direction of the applied stress and the friction stress. On the {111} surface where the Schmid factor for the strain-induced ε-martensite formation is small, homogeneous deformation microstructure covered by it was not developed even after long-time wear, resulting in lower wear resistance. The results strongly suggest that not only the hardness, but the distribution of the ε-martensite is important to control the wear behavior of the Co–Cr alloys with the extremely low stacking fault energy, and it can be achieved by the crystal orientation control in the γ-phase.

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Our paper on CaO-SrO-P2O5-TiO2 bioglass has been published as an open access article in Materials (MDPI).

Sungho Lee*, Fukue Nagata, Katsuya Kato, Takayoshi Nakano, Toshihiro Kasuga:
Structures and dissolution behaviors of quaternary CaO-SrO-P2O5-TiO2 glasses,
Materials, 14 [7], (2021), 1736; 1-13.
https://doi.org/10.3390/ma14071736

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Abstract
Calcium phosphate glasses have a high potential for use as biomaterials because their composition is similar to that of the mineral phase of bone. Phosphate glasses can dissolve completely in aqueous solution and can contain various elements owing to their acidity. Thus, the glass can be a candidate for therapeutic ion carriers. Recently, we focused on the effect of strontium ions for bone formation, which exhibited dual effects of stimulating bone formation and inhibiting bone resorption. However, large amounts of strontium ions may induce a cytotoxic effect, and there is a need to control their releasing amount. This work reports fundamental data for designing quaternary CaO-SrO-P2O5-TiO2 glasses with pyro- and meta-phosphate compositions to control strontium ion-releasing behavior. The glasses were prepared by substituting CaO by SrO using the melt-quenching method. The SrO/CaO mixed composition exhibited a mixed cation effect on the glassification degree and ion-releasing behavior, which showed non-linear properties with mixed cation compositions of the glasses. Sr2+ ions have smaller field strength than Ca2+ ions, and the glass network structure may be weakened by the substitution of CaO by SrO. However, glassification degree and chemical durability of pyro- and meta-phosphate glasses increased with substituted all CaO by SrO. This is because titanium groups in the glasses are closely related to their glass network structure by SrO substitution. The P-O-Ti bonds in pyrophosphate glass series and TiO4 tetrahedra in metaphosphate glass series increased with substitution by SrO. The titanium groups in the glasses were crosslink and/or coordinate phosphate groups to improve glassification degree and chemical durability. Sr2+ ion releasing amount of pyrophosphate glasses with >83% SrO substitution was larger than 0.1 mM at day seven, an amount that reported enhanced bone formation by stimulation of osteogenic markers.

Keywords: bioactive glass; phosphate glass; structure; dissolution behavior; strontium

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Nakano Lab's paper has been published in the Journal of Japanese Society For Bone Morphometry as an open access journal.

T. Matsuzaka, A. Matsugaki, and T. Nakano:
Construction of an anisotropic co-culture model under stress loading to elucidate the mechanism of micro-orientation structure formation in bone,
Journal of the Japanese Society For Bone Morphometry, (2021), 31, 45-51.

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Dr. Nakano was informally selected to receive JSPM Award for Distinguished Achievements in Research from Japan Society of Powder and Powder Metallurgy on June 3, 2021.

Takayoshi Nakano:
Research and Development on Anisotropic Microstructure Control Based on Powder Metallurgy including Three-Dimensional Laminated Metal Fabrication,
JSPM Award for Distinguished Achievements in Research, June 3, 2021, Japan Society of Powder and Powder Metallurgy

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Dr. Matsugaki will receive the Research Encouragement Award of the Biomedical Materials Division, The Society of Materials Sciences, Japan, 2020.

Aira Matsugaki:
Elucidation of the Biological Mechanism of Bone Functionalization and Development of Bone Orientation Inducing Materials Based on the Mechanism,
The Society of Materials Sciences, Japan, the Research Encouragement Award of the Biomedical Materials Division, 2020.

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Dr. Nakano was awarded The 27th Japan Institute of Metals and Materials Masumoto Hakaru Award.

Takayoshi Nakano:
Elucidation of the Mechanism of Bone Microstructure Orientation as a Functional Material and Research on Bone Metal Implants Based on the Mechanism,
The 27th Japan Institute of Metals and Materials Masumoto Hakaru Award, March 16, 2021, The Japan Institute of Metals and Materials.

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A new mechanism for the strengthening of LPSO layers by Mg alloys has been published in Acta Materialia as an open access article.

Koji Hagihara*, Ryohei Ueyama, Michiaki Yamasaki, Yoshihito Kawamura, Takayoshi Nakano:
Surprising increase in yield stress of Mg single crystal using long-period stacking ordered nanoplates,
Acta Materialia, (2021), 116797.
https://doi.org/10.1016/j.actamat.2021.116797

Click here dor this paper.
Click here for this PDF.

Abstract
Mg–Zn–Y ternary alloys containing the long-period stacking ordered (LPSO) phase exhibit superior mechanical properties. This is believed to be originating from the LPSO phase acting as the strengthening phase. However, we first clarify that the mechanical properties of the matrix Mg solid solution in the Mg/LPSO two-phase alloy are significantly different from those of pure Mg. The yield stress of a Mg99.2Zn0.2Y0.6 single crystal (matrix Mg solid solution) is almost the same as that of an LPSO single-phase alloy. This is ascribed to the formation of thin stacking-fault-like defects, named “LPSO nanoplate”. In Mg99.2Zn0.2Y0.6, kink-band formation is induced in the same manner as that in the LPSO phase in deformation, resulting in high strength accompanied with increased ductility. Our results suggest that the strengthening mechanism of the Mg/LPSO two-phase alloy must be reconsidered depending on the microstructure. Furthermore, the results suggest that new ultrahigh-strength Mg alloys, which have much lower Zn and Y contents but the mechanical properties are comparable or superior than the present Mg/LPSO two-phase alloys, are expected to be developed via the appropriate control of LPSO nanoplate microstructures.

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Our paper has been published in The Journal of The Society of Inorganic Materials in Open Access.

Seong-Ho Lee, Okue Nagata, Katsuya Kato, Takayoshi Nakano, Toshihiro Kasuga:
Improving chemical durability of calcium phosphate invert glasses by Al2O3 addition,
The Journal of The Society of Inorganic Materials, (2021), 28, 67-73.

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The results of a collaorate research project with the Department of Orthopaedic Surgery, Osaka University on bone control using magnetic fields have been published in the journal "Bone Reports" as open access.

Rintaro Okada, Kai Yamato, Minoru Kawakami, Joe Kodama, Junichi Kushioka, Daisuke Tateiwa , Yuichiro Ukon , Bal Zeynep, Takuya Ishimoto, Takayoshi Nakano, Hideki Yoshikawa, Takashi Kaito*:
Low magnetic field promotes recombinant human BMP-2-induced bone formation and influences orientation of trabeculae and bone marrow-derived stromal cells,
Bone Reports, (2021), 100757; 1-.
https://doi.org/10.1016/j.bonr.2021.100757

Click here for this paper.
Click here for this PDF.

Abstract
Effects of high magnetic fields [MFs, ≥ 1 T (T)] on osteoblastic differentiation and the orientation of cells or matrix proteins have been reported. However, the effect of low MFs (< 1 T) on the orientation of bone formation is not well known. This study was performed to verify the effects of low MFs on osteoblastic differentiation, bone formation, and orientation of both cells and newly formed bone. An apparatus was prepared with two magnets (190 mT) aligned in parallel to generate a parallel MF. In vitro, bone marrow-derived stromal cells of rats were used to assess the effects of low MFs on cell orientation, osteoblastic differentiation, and mineralization. A bone morphogenetic protein (BMP)-2-induced ectopic bone model was used to elucidate the effect of low MFs on microstructural indices, trabecula orientation, and the apatite c-axis orientation of newly formed bone. Low MFs resulted in an increased ratio of cells oriented perpendicular to the direction of the MF and promoted osteoblastic differentiation in vitro. Moreover, in vivo analysis demonstrated that low MFs promoted bone formation and changed the orientation of trabeculae and apatite crystal in a direction perpendicular to the MF. These changes led to an increase in the mechanical strength of rhBMP-2-induced bone. These results suggest that the application of low MFs has potential to facilitate the regeneration of bone with sufficient mechanical strength by controlling the orientation of newly formed bone.

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Our laboratory's commentary was published in Precision Medicine's "Utilization of Personal Health Records" (March issue).

Aira Matsugaki, Takuya Ishimoto, Ryosuke Ozasa, Naoko Ikeo, Takayoshi Nakano:
Evaluation and control of bone collagen/apatite orientation for the realization of personal bone quality medicine,
Precision Medicine "Utilization of personal health record", Vol. 4, March, (2021),pp.59-68 (245-254).
Click here for this commentary.
Click here for this PDF.

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Our laboratory's commentary will appear in the March issue of Precision Medicine's "Utilization of Personal Health Records".

Aira Matsugaki, Takuya Ishimoto, Ryosuke Kozasa, Naoko Igeo, and Takayoshi Nakano:
Evaluation of bone collagen/apatite orientation and its control for the realization of personal bone quality medicine,
Precision Medicine "Utilization of personal health record", March, (2021), in press.

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The results of a collaborative study with the Department of Orthopaedic Surgery of Osaka University on bone control using magnetic fields have been accepted for publication in Bone Reports and will be open access.

Rintaro Okada, Kai Yamato, Minoru Kawakami, Joe Kodama, Junichi Kushioka, Daisuke Tateiwa , Yuichiro Ukon , Bal Zeynep, Takuya Ishimoto, Takayoshi Nakano, Hideki Yoshikawa, Takashi Kaito*:
Low magnetic field promotes recombinant human BMP-2-induced bone formation and influences orientation of trabeculae and bone marrow-derived stromal cells,
Bone Reports, (2021), in press.

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Our article on the early ossification process has been published in Tissue Engineering as an open access article.

Emilio Satoshi Hara, Masahiko Okada, Noriyuki Nagaoka, Takayoshi Nakano, Takuya Matsumoto*:
Re-evaluation of initial bone mineralization from an engineering perspective,
Tissue Engineering, Review Article-Part B, (2021), online.
https://doi.org/10.1089/ten.TEB.2020.0352

Click here for this paper.
Click here for this PDF.

Abstract
Bone regeneration was one of the earliest fields to develop in the context of tissue regeneration, and currently, repair of small-sized bone defects has reached a high success rate. Future researches are expected to incorporate more advanced techniques towards achieving rapid bone repair and modulation of the regenerated bone quality. For these purposes, it is important to have a more integrative understanding of the mechanisms of bone formation and maturation from multiple perspectives and to incorporate these new concepts into the development and designing of novel materials and techniques for bone regeneration. This review focuses on the analysis of the earliest stages of bone tissue development from the biology, material science, and engineering perspectives for a more integrative understanding of bone formation and maturation, and for the development of novel biology-based engineering approaches for tissue synthesis in vitro. More specifically, the authors describe the systematic methodology that allowed the understanding of the different nucleation sites in intramembranous and endochondral ossification, the space-making process for mineral formation and growth, as well as the process of apatite crystal cluster growth in vivo in the presence of suppressing biomolecules.

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Mr. Ryo Fukushima (M1) was awarded the Best Presentation Award at The Iron and Steel Institute of Japan, The Japan Institute of Metals and Materials Kansai Branch, The 2nd Conference on Materials Science and Engineering (Student Conference) held on Februa

Ryo Fukushima:
Elucidation of the mechanism of bone mechanics control originating from trace metal elements,
Best Presentation Award, The Iron and Steel Institute of Japan and The Japan Institute of Metals and Materials Kansai Branch, (2021), Feb. 4, 2021 (WEB)

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A novel BioHEA capable of tensile deformation was successfully fabricated and published in Materials & Design as open access. It is expected to be developed into new practical applications.

Yuuka Iijima, Takeshi Nagase, Aira Matsugaki, Pan Wang, Kei Ameyama, Takayoshi Nakano*:
Design and development of Ti-Zr-Hf-Nb-Ta-Mo high-entropy Alloys for metallic biomaterials,
Materials & Design, (2021), in press.
https://doi.org/10.1016/j.matdes.2021.109548

Click here for this paper.
Click here for this PDF.

Abstract
Applying empirical alloy parameters (including Mo equivalent), the predicted ground state diagram, and thermodynamic calculations, noble nonequiatomic Ti–Zr–Hf–Nb–Ta–Mo high-entropy alloys for metallic biomaterials (BioHEAs) were designed and newly developed. It is found that the Moeq and valence electron concentration (VEC) parameters are useful for alloy design involving BCC structure formation in bio medium-entropy alloys and BioHEAs. Finally, we find a Ti28.33Zr28.33Hf28.33Nb6.74Ta6.74Mo1.55 (at.%) BioHEA that exhibits biocompatibility comparable to that of CP–Ti, higher mechanical strength than CP–Ti, and an appreciable room-temperature tensile ductility. The current findings pave the way for new Ti–Zr–Hf–Nb–Ta–Mo BioHEAs development and are applicable for another BioHEA alloys system.

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Our paper on microstructure control to improve mechanical properties of Co-Cr-W-Ni for biomedical applications has been published in Materials Transactions.

Kosuke Ueki, Soh Yanagihara, Kyosuke Ueda, Masaaki Nakai, Takayoshi Nakano, Takayuki Narushima:
Improvement of Mechanical Properties by Microstructural Evolution of Biomedical Co-Cr-W-Ni Alloys with the Addition of Mn and Si,
Materials Transactions, 62 [2], (2021), 229-238.

Click here for this paper.
Click here for this PDF.

Abstract
We investigated changes in the microstructure and mechanical properties of biomedical Co-20Cr-15W-10Ni alloys (mass%) containing 8 mass% Mn and 0-3 mass% Si due to hot forging, solution treatment, cold swaging, and static recrystallization. The η-phase (M6X-M12X type cubic structure, M: metallic elements, X: C and/or N, space group: Fd-3m (227)) and CoWSi type Laves phase (C14 MgZn2 type hexagonal structure, space group: P63/mmc (194)) were confirmed as precipitates in the as-cast and as-forged alloys. To the best of our knowledge, this is the first report that reveals the formation of CoWSi type Laves phase precipitates in Co-Cr-W-Ni-based alloys. The addition of Si promoted the formation of precipitates of both η-phase and CoWSi type Laves phase. The solution-treated 8Mn+(0, 1)Si-added alloys exhibited TWIP-like plastic deformation behavior with an increasing work-hardening rate during the early to middle stages of plastic deformation. This plastic deformation behavior is effective in achieving both the low yield stress and high strength required to develop a high-performance balloon-expandable stent. The 8Mn+2Si-added alloy retained the CoWSi type Laves phase even after solution treatment, such that the ductility decreased but the strength improved. Additions of Mn and Si are effective in improving the ductility and strength of the Co-Cr-W-Ni alloy, respectively.

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An open-access paper was published in MDPI's "Biomolecules" (IF=4.082) on osteoblast disruption, which is closely related to the formation of bone matrix in cancer (melanoma) bone metastases.

Aira Matsugaki*, Yumi Kimura, Ryota Watanabe, Fumihito Nakamura, Ryo Takehana, Takayoshi Nakano*:
Impaired alignment of bone matrix microstructure associated with disorganized osteoblast arrangement in malignant melanoma metastasis,
Biomolecules, 11(2), (2021), 131: 1-9.
https://doi.org/10.3390/biom11020131

Click here for this paper.
Click here for this PDF.

Abstract
Malignant melanoma favors spreading to bone, resulting in a weakened bone with a high fracture risk. Here, we revealed the disorganized alignment of apatite crystals in the bone matrix associated with the homing of cancer cells by developing an artificially controlled ex vivo melanoma bone metastasis model. The ex vivo metastasis model reflects the progressive melanoma cell activation in vivo, resulting in decreased bone mineral density and expression of MMP1-positive cells. Moreover, less organized intercellular connections were observed in the neighboring osteoblasts in metastasized bone, indicating the abnormal and randomized organization of bone matrix secreted by disconnected osteoblasts. Our study revealed that the deteriorated microstructure associated with disorganized osteoblast arrangement was a determinant of malignant melanoma-related bone dysfunction.
Keywords: malignant melanoma; ex vivo metastasis model; bone tissue microstructure; osteoblast

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Dr. Nakano's column article appeared in today's Nikkan Kogyo Shimbun.

Thank you for your filial piety,
Nikkan Kogyo Shimbun, January 19, 2021, Morning Edition, page 23 (Science and Technology, University)

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Our paper on micro-simulation of crystal aggregate microstructure formation in AM has been published in the Journal of the Japan Institute of Metals.

Jun Kubo, Yuichiro Koizumi, Takuya Ishimoto and Takayoshi Nakano:
Microscopic simulation by improved CA method for clarifying the mechanism of crystal aggregate microstructure formation in laser additive manufacturing,
Journal of the Japan Institute of Metals and Materials, (2021), in press.
DOI: https://doi.org/10.2320/jinstmet.J2020028

Click here for this paper.

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An article on the suppression of crack formation in heat-resistant materials by metal 3D printers appeared on page 25 of today's Nikkan Kogyo Shimbun.

Heat-Resistant Material Crack Prevention by Metal 3D Printer at Osaka University
Nikkan Kogyo Shimbun, Jan. 13, 2021, Morning Edition, page 25 (Science and Technology, University)
Click here for this electric version

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The proceedings of Thermec2021 was published in Materials Science Forum.

K. Ueki, S. Yanagihara, K. Ueda, M. Nakai, T. Nakano and T. Narushima:
Improvement of Strength and Ductility by Combining Static Recrystallization and Unique Heat Treatment in Co-20Cr-15W-10Ni Alloy for Stent Application,
Materials Science Forum, 1016, (2021), 1503-1509.

M. Todai, T. Nagase and T. Nakano:
Fabrication of Be-Ta Ti Alloys without Pre-Alloyed Powders via SLM,
Materials Science Forum, 1016, (2021), 1797-1801.

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2020

A collaborative research paper with Dr. Ebina of the Department of Orthopaedic Surgery, Osaka University, has been published as an open access article in the International Journal of Molecular Sciences.

Gensuke Okamura, Kosuke Ebina*, Makoto Hirao, Ryota Chijimatsu, Yasukazu Yonetani, Yuki Etani, Akira Miyama, Kenji Takami, Atsushi Goshima, Hideki Yoshikawa, Takuya Ishimoto, Takayoshi Nakano, Masayuki Hamada, Takashi Kanamoto, Ken Nakata:
Promoting effect of basic fibroblast growth factor in synovial mesenchymal stem cell-based cartilage regeneration,
International Journal of Molecular Sciences, 22, (2021), 300: 1-16.
https://doi.org/10.3390/ijms22010300

Click here for this paper.

Abstract
Synovial mesenchymal stem cell (SMSC) is the promising cell source of cartilage regeneration but has several issues to overcome such as limited cell proliferation and heterogeneity of cartilage regeneration ability. Previous reports demonstrated that basic fibroblast growth factor (bFGF) can promote proliferation and cartilage differentiation potential of MSCs in vitro, although no reports show its beneficial effect in vivo. The purpose of this study is to investigate the promoting effect of bFGF on cartilage regeneration using human SMSC in vivo. SMSCs were cultured with or without bFGF in a growth medium, and 2 × 105 cells were aggregated to form a synovial pellet. Synovial pellets were implanted into osteochondral defects induced in the femoral trochlea of severe combined immunodeficient mice, and histological evaluation was performed after eight weeks. The presence of implanted SMSCs was confirmed by the observation of human vimentin immunostaining-positive cells. Interestingly, broad lacunae structures and cartilage substrate stained by Safranin-O were observed only in the bFGF (+) group. The bFGF (+) group had significantly higher O’Driscoll scores in the cartilage repair than the bFGF (−) group. The addition of bFGF to SMSC growth culture may be a useful treatment option to promote cartilage regeneration in vivo.

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A paper on shape control of BioHEA alloys using AM and strengthening by forced solid solution, which was led by Nakano Lab. with groups in Germany and Korea, has been published in Scripta Materialia with open access.

Takuya Ishimoto, Ryosuke Ozasa, Kana Nakano, Markus Weinmann, Christoph Schnitter, Melanie Stenzel, Aira Matsugaki, Takeshi Nagase, Tadaaki Matsuzaka, Mitsuharu Todai, Hyoung Seop Kim, Takayoshi Nakano*: Development of TiNbTaZrMo bio-high entropy alloy (BioHEA) super-solid solution by selective laser melting, and its improved mechanical property and biocompatibility, Scripta Materialia, 194 (2020) 113658; 1-6.
DOI: 10.1016/j.scriptamat.2020.113658

Click here for this paper.
Click here for this PDF.

Abstract
BioHEAs, specifically designed high entropy alloy (HEA) systems for biomedical applications, represent a new era for biometals. However, recent challenges are (1) the poor shape customizability, and (2) the inevitable severe segregation due to the intrinsic fact that HEA is an ultra-multicomponent alloy system. To achieve shape customization and suppression of elemental segregation simultaneously, we used an extremely high cooling rate (~107 K/s) of the selective laser melting (SLM) process. We, for the first time, developed pre-alloyed Ti1.4Nb0.6Ta0.6Zr1.4Mo0.6 BioHEA powders and SLM-built parts with low porosity, customizable shape, excellent yield stress, and good biocompatibility. The SLM-built specimens showed drastically suppressed elemental segregation compared to the cast counterpart, representing realization of a super-solid solution. As a result, the 0.2% proof stress reached 1690 ± 78 MPa, which is significantly higher than that of cast Ti1.4Nb0.6Ta0.6Zr1.4Mo0.6 (1140 MPa). The SLM-built Ti1.4Nb0.6Ta0.6Zr1.4Mo0.6 BioHEA is promising as a next-generation metallic material for biomedical applications.

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Dr. Nakano has been selected for the 27th The Japan Institute of Metals and Materials Masumoto Hakaru Award. He will give the award-winning lecture at the Spring Lecture Meeting.

Nakano Takayoshi:
Elucidation of the mechanism of bone microstructure orientation as a functional material and research on metal bone implants based on this mechanism,
March 2021

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A report on the activities of the research group in which Dr. Ishimoto and Dr. Matsugaki participated has been published in Materia.

Yusuke Tsutsumi, Takuya Ishimoto, Kyousuke Ueda, Shinpei Maruyama, Tetsushi Kuze, Aira Matsugaki, Maki Ashida, Chen Peng:
Research and Development of Ultra High Corrosion Resistance Metallic Materials Higher Corrosion Resistance of Martensitic Stainless Steels by Laser Additive Manufacturing, Report of Young Researchers Group
Mateliah, 59, 12, (2020), pp.679-684
Click here for PDF.

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Dr. Matsugaki received the 2020 Science Encouragement Award from The Japanese Society for Biomaterials and gave an award lecture.

Matsugaki Aira:
Control of bone orientation by biomaterials, based on cell biology
The Japanese Society for Biomaterials Award Ceremony and Award Lectures, Kansai University, November 30, 2020 15:20-15:40

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Nakano's paper won the 2020 paper award in Smart Process Society for Materials, Environment & Energy .

The award ceremony was held at the scientific conference (on line), where he received a certificate from the President of the Society of Japan (Junction Research Institute) and the
Doctoral student Amano gave the award lecture.

Hiroki Amano, Yusuke Yamaguchi, Sasaki Tomoaki, Toyoyuki Sato, Takuya Ishimoto and Takayoshi Nakano.
Effect of Oxygen in the Atmosphere on Spatter Generation in Laser Deposition
Vol. 8, No. 3, (2019), pp. 102-105.

*Photographed with permission of the office.

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Research on the layered structure and mechanical properties of fish vertebrae has been published for open access in "Materials" , in collaborate with Okayama Univ.

YuYang Jiao, Masahiro Okada, Emilio Satoshi Hara, ShiChao Xie, Noriyuki Nagaoka, Takayoshi Nakano, Takuya Matsumoto*:
Micro-architectural investigation of teleost fish rib inducing pliant mechanical property,
Materials, 13, (2020), 5099;1-9.
doi:10.3390/ma13225099.

This is the rink of research paper
This is the PDF

Abstract:
Despite the fact that various reports have been discussing bone tissue regeneration, precise bone tissue manipulation, such as controlling the physical properties of the regenerated bone tissue, still remains a big challenge. Here, we focused on the teleost fish ribs showing flexible and tough mechanical properties to obtain a deeper insight into the structural and functional features of bone tissue from different species, which would be valuable for the superior design of bone-mimicking materials. Herein, we examined their compositions, microstructure, histology, and mechanical properties. The first rib of Carassius langsdorfii showed a higher Young’s modulus with a small region of chondrocyte clusters compared with other smaller ribs. In addition, highly oriented collagen fibers and osteocytes were observed in the first rib, indicating that the longest first rib would be more mature. Moreover, the layer-by-layer structure of the oriented bone collagen was observed in each rib. These microarchitectural and compositional findings of fish rib bone would give one the useful idea to reproduce such a highly flexible rib bone-like material.

Keywords: bone-like material; mechanical property; orientation; layered structure

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Mr. Ueyama was awarded the Best Poster Award at The Japan Institute of Light Metals Fall Meeting 2020.

○Ryohei Ueyama, Koji Hagiwara, Michiaki Yamazaki, Yoshito Kawamura and Takayoshi Nakano
Plastic deformation behavior of mille-feuille type magnesium alloy , cited.
Best Poster Award, The Light Metal Society Fall 2020 Conference (139th Annual Meeting) (@Web on-line)

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The new AM Center brochure is now available.

The new AM Center brochure is now available.
We will continue to push forward with our research.

This is the new brochure.

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Dr. Nakano gave a keynote speech at the JTM Kansai Seminar "Reliability Today and Tomorrow".

Takayoshi Nakano:.
High performance, based on shape and material control by 3D metal stacked molding (AM)
Keynote Address, Mielparque Shin-Osaka, Thursday, November 5, 2020, 13:40-15:00

Click here to visit website.

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An article about the Osaka University AM Center, of which Dr. Nakano is the director, was published in the quarterly magazine "Hito-to-system".

The quarterly magazine "Hito To Sysytem" published an article about the Osaka University AM Center (Anisotropic Custom Design and AM Research and Development Center), of which Dr. Nakano serves as the director, titled "A Research Institution that Opens Up the Future of Monozukuri with AM" (2020.10). The article describes the background to the establishment of the AM Center, its research and development concept, past efforts and achievements, and future prospects, based on on-site interviews. A particular highlight of the article is the introduction of the efforts made by the core members of the AM Center on the theme of "Anisotropy". Please take a look at it.

Click here to view the website.
Click here to view PDF.

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The commentary article is published in the journal Matelia. In addition, many of the winners of the Poster Award, the Materia Paper Award, and the Incentive Award are listed in the article.

Aira Matsugaki, Takayoshi Nakano:
Induction of bone functioning based on the mechanism of orientation of cells and bone matrix, by
Materia, 59 [11], (2020), 594-599.

Click here to PDF
Click here for the whole of the November Matelia issue (the drawing of the Matelia article by Nakano Lab. appears on the cover)

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Two international conference papers from The 14th World Conference on Titanium (Ti 2019) have been published as open access.

Takayoshi Nakano, Takuya Ishimoto, Aira Matsugaki, Koji Hagihara, Yuichiro Koizumi and Ryosuke Ozasa:
Control of crystallographic orientation by metal additive manufacturing process of β-type Ti alloys based on the bone tissue anisotropy,
MATEC Web of Conferences 321, (2020), 05002: 1-11.

Click here for the paper.
Click here for a PDF of the paper.

Abstract
Variation in the scanning strategy for β-type Ti alloys during additive manufacturing (AM) enables the fabrication of a singlecrystal-like microstructure possessing a crystallographic texture, in which the low-Young’s modulus-<100> direction is aligned along a specific direction. Thus, metal biomaterial with low elasticity, comparable to the bone Young’s modulus, can be developed by AM, which will contribute to suppress the stress shielding of bone and prevent degradation of bone tissue anisotropy.

M. Niinomi*, T. Akahori, M. Nakai, Y. Koizumi, A. Chiba, T. Nakano, T. Kakeshita, Y. Yamabe-Mitarai, S. Kuroda, N. Motohashi, Y. Itsumi, T. Choda:
Quantitative relationship between microstructural factors and fatigue life of Ti-5Al-2Sn-2Zr-4Cr-4 Mo (Ti-17) fabricated using a 1500-ton forging simulator,
MATEC Web of Conferences 321, (2020), 11015; 1-5.

Click here for the paper.
Click here for a PDF of the paper.

Abstract
The microstructures, tensile properties, and fatigue lives of the forged Ti-17 using a 1500-ton forging simulator subjected to different solution treatments and a common aging treatment under both load- and strain-controlled conditions to evaluate high cycle fatigue and low cycle fatigue lives, respectively were examined. Then, the tensile properties, microstructures, and relationships between fatigue lives and the microstructural factors were discussed.

The fatigue limit under load-controlled conditions increases with increasing solution treatment temperature up to 1143 K, which is in the (α + β) region. However, it decreases with further increase in the solution treatment temperature to 1203 K in the b region. The fatigue ratio at fatigue limit is increasing with decreasing solution treatment temperature, namely increasing the volume fraction of the primary α phase, and it relates well qualitatively with the volume fraction of the primary α phase when the solution treatment temperature is less than the b transus temperature. The fatigue life under strain-controlled conditions to evaluate the low cycle fatigue life increases with decreasing solution treatment temperature, namely increasing the volume fraction of the primary α phase. The fatigue life under strain-controlled conditions to evaluate the low cycle fatigue life relates well quantitatively with the tensile true strain at breaking of the specimen and the volume fraction of the primary α phase for each total strain range.

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Our paper was accepted for publication in Journal of the Society of Inorganic Materials, Japan.

Li Sung-ho, Nagata Hisae, Kato Katsuya, Nakano Takayoshi and Kasuga Toshihiro
Improving chemical durability of calcium phosphate invert glasses by Al2O3 addition
Journal of the Society of Inorganic Materials, Japan, (2020) in press.

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Dr. Nakano gave an invited lecture at the 3rd Nagoya Automotive Lightening Technology Expo, Nagoya Weight Reduction Innovation Forum 2020.

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Takayoshi Nakano
Exploring the world of atomic alignment control through metal 3D printing
Invited lecture, Port Messe Nagoya, Thursday, October 22, 2020, 15:00 - 16:30

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Certificate of Excellence for the 35th Annual Fall Lecture Conference.

The award for the 33rd The Japan Institute of Metals and Materials The Best Poster Awards Fall Meeting 2020 has arrived.

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A group photo of the four winners

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Yusuke Okaoka, Ryosuke Osasa and Takayoshi Nakano:
Disruption of bone microstructure and physiological function in phosphorus metabolic failure,
35th Annual Best Poster Award of the Japan Institute of Metals, September 15, 2020

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Shun Matsumoto, Aira Matsugaki, Takayoshi Nakano:
Somatic cell sequence changes in response to macrophage activity
35th Annual Best Poster Award of the Japan Institute of Metals, September 15, 2020

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Moritaka Mori, Takuya Ishimoto, Kouta Kimura, Takayoshi Nakano:
Design of anisotropic function by hierarchical structure control using laser stacking method
35th Annual Best Poster Award of the Japan Institute of Metals, September 15, 2020

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Ryohei Ueyama, Koji Hagiwara, Michiaki Hagisawa, Yoshihito Kawamura and Takayoshi Nakano
Technical properties of mille-feuille Mg alloy single crystals
35th Annual Best Poster Award of the Japan Institute of Metals, September 15, 2020

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Collaborative research with the Department of Pediatrics and Orthopedics of The Jikei University School of Medicine has been published in 'Molecular Therapy- Methods & Clinical Development' as an open access journal.

Miho Wada, Yohta Shimada, Sayoko Iizuka, Natsumi Ishii, Hiromi Hiraki, Toshiaki Tachibana, Kazuhiro Maeda, Mitsuru Saito, Shoutaro Arakawa, Takuya Ishimoto, Takayoshi Nakano, Hiroyuki Ida, Toya Ohashi, Hiroshi Kobayashi*:
Ex-vivo gene therapy treats bone complications of mucopolysaccharidosis type II mouse models through bone remodeling reactivation, Molecular Therapy- Methods & Clinical Development, Volume 19, 11 December 2020, pp.261-274.

Click here for the paper.
Click here for a PDF of the paper.

ABSTRACT
Mucopolysaccharidosis type II is a disease caused by organ accumulation of glycosaminoglycans due to iduronate 2-sulfatase deficiency. This study investigated the pathophysiology of the bone complications associated with mucopolysaccharidosis II and the effect of lentivirus-mediated gene therapy of hematopoietic stem cells on bone lesions of mucopolysaccharidosis type II mouse models in comparison with enzyme replacement therapy. Bone volume, density, strength, and trabecular number were significantly higher in the untreated mucopolysaccharidosis type II mice than in wild type. Accumulation of glycosaminoglycans caused reduced bone metabolism. Specifically, persistent high serum iduronate 2-sulfatase levels and release of glycosaminoglycans from osteoblasts and osteoclasts in mucopolysaccharidosis type II mice that had undergone gene therapy reactivated bone lineage remodeling, subsequently reducing bone mineral density, strength, and trabecular number to a similar degree as that observed in wild type mice. Bone formation, resorption parameters, and mineral density in the diaphysis edge did not appear to have been affected by the irradiation administered as a pre-treatment for gene therapy. Hence, the therapeutic effect of gene therapy on the bone complications of mucopolysaccharidosis type II mice possibly outweighed that of enzyme replacement therapy in many aspects.

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An article on bone fragility caused by inflammatory cytokines was published in today's Nikkan Kogyo Shimbun.

Cytokines, bone fragility - Osaka University discovers factors in inflammatory diseases
Nikkan Kogyo Shimbun, October 15, 2020, Morning Edition, page 21 (Science, Technology and University)

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The 1st Forum on Digital Art and Design Engineering (web-based) was held at Osaka University, Graduate School of Engineering, at 13:00-18:00 on Monday, October 12, 2020, with Prof. Takayoshi Nakano as a supervisor.

The 1st Forum on Digital Art and Design Engineering (web-based) was held in the Techno-Arena, Osaka University on Monday, October 12, 2020, from 13:00 to 18:00, with Prof. Takayoshi Nakano as the chief referee.
It was a very successful forum with 250 participants.

--------- program ----------------
13:00-13:10 ◆ Opening Remarks
Opening Remarks
Professor NAKANO Takayoshi (Department of Materials Science and Engineering, Osaka University)
speech
13:10-13:30
1 "Strategies of the Graduate School of Engineering, Osaka University and the Techno-Arena
Professor Noboru Babaguchi (Dean of the Graduate School of Engineering, Osaka University)

13:30-14:00
2「The World of Anisotropic 3D Modeling: Molecular Orientation Generates Functions
Prof. Masanori Ozaki (Department of Electrical, Electronic and Communication Engineering, Osaka University Graduate School of Engineering)

14:00-14:30
3 "Anisotropy in Biological Bones and the World of Materials Science Played by Metal 3D Printers
Professor Takayoshi NAKANO (Department of Materials Science and Engineering, Graduate School of Engineering, Osaka University)

14:40-15:10
4 "The Challenge of New Monozukuri in Medical and Food Fields by Integrating Biotechnology and Printers
Professor Noriya Matsuzaki (Department of Applied Chemistry, Osaka University Graduate School of Engineering)

15:10-15:40
5 "Cyber-Physical Systems and Manufacturing in 3D Printing
Professor Yuichiro Koizumi (Department of Materials Science and Engineering, Osaka University Graduate School of Engineering)

15:50-16:20
6 "A Theoretical and Applied Mechanics Approach to Realize Functional Structures Based on Micro Instability
Prof. Akihiro Nakatani (Department of Mechanical Engineering, Graduate School of Engineering, Osaka University)

16:20-16:50
7 "Manufacturing Innovation from Future Design
Professor Keishiro Hara (Future Innovation Center, Osaka University Graduate School of Engineering)

17:20-17:50
8 "The Future of Global Manufacturing
Prof. Atsushi Maekawa, Visiting Professor at Osaka University (Chairman of TRAFAM, Former Vice President of Mitsubishi Heavy Industries)

17:20-17:50
General Discussion / Summary
(Facilitator: Professor Takashi Hayashi, Director of the Future Innovation Center, Osaka University Graduate School of Engineering)

17:50-18:00 ◆ Closing Remarks
Closing Remarks
Professor Takashi Hayashi, Director of the Future Innovation Center, Osaka University Graduate School of Engineering

exchange meeting
18:00 - WEB Mixer (free of charge)

Translated with www.DeepL.com/Translator (free version)

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The results of the joint research with Niigata University School of Medicine, Fukushima Medical University and Oita University of Nursing and Rehabilitation Sciences on the inhibitory effect of Type-I Angiotensin II receptor blockade on uremic bone minera

Takuya Wakamatsu, Yoshiko Iwasaki, Suguru Yamamoto, Koji Matsuo, Shin Goto, Ichiei Narita, Junichiro J Kazama, Kennichi Tanaka, Akemi Ito, Ryosuke Ozasa, Takayoshi Nakano, Chisato Miyakoshi, Yoshihiro Onishi, Shingo Fukuma, Shunichi Fukuhara, Hideyuki Yamato, Masafumi Fukagawa, Tadao Akizawa:
Type I Angiotensin II Receptor Blockade Reduces Uremia‐Induced Deterioration of Bone Material Properties, (2020), https://doi.org/10.1002/jbmr.4159

Click here for the paper.
Click here for the PDF.

ABSTRACT
Chronic kidney disease (CKD) is associated with a high incidence of fractures. However, the pathophysiology of this disease is not fully understood, and limited therapeutic interventions are available. This study aimed to determine the impact of type 1 angiotensin II receptor blockade (AT‐1RB) on preventing CKD‐related fragility fractures and elucidate its pharmacological mechanisms. AT‐1RB use was associated with a lower risk of hospitalization due to fractures in 3276 patients undergoing maintenance hemodialysis. In nephrectomized rats, administration of olmesartan suppressed osteocyte apoptosis, skeletal pentosidine accumulation, and apatite disorientation, and partially inhibited the progression of the bone elastic mechanical properties, while the bone mass was unchanged. Olmesartan suppressed angiotensin II‐dependent oxidation stress and apoptosis in primary cultured osteocytes in vitro. In conclusion, angiotensin II‐dependent intraskeletal oxidation stress deteriorated the bone elastic mechanical properties by promoting osteocyte apoptosis and pentosidine accumulation. Thus, AT‐1RB contributes to the underlying pathogenesis of abnormal bone quality in the setting of CKD, possibly by oxidative stress. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

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A joint research paper with Tohoku University's Narushima Laboratory showing that microstructure control by metal AM improves the oxidation resistance of Cr has been published in Additive Manufacturing (Elsevier) as an open access Pre-Proof.

Ozkan Gokcekaya, Naohiro Hayashi, Takuya Ishimoto, Kyosuke Ueda, Takayuki, Narushima, Takayoshi Nakano*: Crystallographic orientation control of pure chromium via laser powder-bed fusion and improved high temperature oxidation resistance,
Additive Manufacturing, (2020), 101624
https://doi.org/10.1016/j.addma.2020.101624

Click here for the paper.
Click here for the PDF.

Abstract
This is the first comprehensive study on the development of a cubic crystallographic texture in pure chromium (Cr) manufactured using laser powder bed fusion (LPBF) with different laser energy densities to alter its microstructure and high-temperature oxidation behavior. An increase in the laser energy density led to the formation of a strong crystallographic texture, which was preferentially oriented in the (100) plane, and there were microstructural improvements in the pure Cr. The grain size of the (100)-oriented Cr was larger than that of the randomly oriented Cr. In addition, the high-angle grain boundary and coincident site lattice (CSL) boundary characteristics were altered. The (100)-oriented Cr exhibited a decrease in the oxide thickness that was due to the decrease in the grain boundary density with a larger grain size and an increase in the CSL boundary ratio. In contrast, the Cr with a random texture showed higher oxidation kinetics and spallation of the oxide layer. The oxidation kinetics of the pure Cr manufactured using LPBF obeyed the parabolic rate law. However, the crystal orientation affected the oxidation of the Cr as the (100)-oriented pure Cr displayed a lower parabolic rate constant, indicating that the (100)-oriented Cr was oxidation-resistant. This is the first report to demonstrate the cubic crystallographic texture formation and the improvement of high-temperature oxidation resistance in Cr manufactured using LPBF.

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The results of our collaboration with Osaka University Graduate School of Dentistry have been published in PLOS ONE as open access.

Saori Matsui, Naomichi Yoneda, Hazuki Maezono*, Katsutaka Kuremoto, Takuya Ishimoto, Takayoshi Nakano, Hiromichi Yumoto, Shigeyuki Ebisu, Yuichiro Noiri, Mikako Hayashi:
Assessment of the functional efficacy of root canal treatment with high frequency waves in rats,
PLoS ONE 15(9), e0239660.
https://doi.org/10.1371/journal.pone.0239660.

Click here for the paper.
Click here for the PDF.

Abstract

The purpose of this study was to develop a high-frequency wave therapy model in rats and to investigate the influence of high-frequency waves on root canal treatment, which may provide a novel strategy for treating apical periodontitis. Root canal treatments with and without high-frequency wave irradiation were performed on the mandibular first molars of 10-week-old male Wistar rats. The mesial roots were evaluated radiologically, bacteriologically, and immunohistochemically. At 3 weeks after root canal treatment, lesion volume had decreased significantly more in the irradiated group than in the non-irradiated group, indicating successful development of the high-frequency therapy model. The use of high-frequency waves provided no additional bactericidal effect after root canal treatment. However, high-frequency wave irradiation was found to promote healing of periapical lesions on the host side through increased expression of fibroblast growth factor 2 and transforming growth factor-β1 and could therefore be useful as an adjuvant nonsurgical treatment for apical periodontitis.

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Four posters from Nakano Lab were selected for The Japan Institute of Metals and Materials The Metals Best Poster Award, 2020 autumn.

Yusuke Okaoka, Ryosuke Ozasa and Takayoshi Nakano:
Disruption of bone microstructure and physiological function in phosphorus metabolic failure,
35th Annual Best Poster Award of the Japan Institute of Metals, September 15, 2020

Shun Matsumoto, Aira Matsugaki and Takayoshi Nakano:
Somatic cell sequence changes in response to macrophage activity
35th Annual Best Poster Award of the Japan Institute of Metals, September 15, 2020

Moritaka Mori, Takuya Ishimoto, Kouta Kimura and Takayoshi Nakano:
Design of anisotropic function by hierarchical structure control using laser stacking method
35th Annual Best Poster Award of the Japan Institute of Metals, September 15, 2020

Ryoheii Kamihara, Koji Hagiwara, Michiaki Hagisawa, Yoshihito Kawamura and Takayoshi Nakano
Technical properties of mille-feuille Mg alloy single crystals
35th Annual Best Poster Award of the Japan Institute of Metals, September 15, 2020

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Nakano Lab members participated in the 167th Annual Meeting of the Japan Institute of Metals and Materials (held online).

Dr. Nakano and Dr. Ishimoto chaired the session on basic biomaterials and biological response (1) and Dr. Ozasa chaired the session on biomaterial design and development.
The presentations were as follows.

Encouragement Award Lecture

〇Ryosuke Ozasa:
Mechanism of aggregate microstructure formation in hard tissues based on metallic materials engineering

Oral presentation

〇Takuya Ishimoto, Takayoshi Nakano:
Induction of regenerated bone oriented to bone defects

〇Aira Matsugaki, Tatsuki Harada and Takayoshi Nakano:
Mechanism of microstructural disruption of bone by malignant tumor formation

〇Yukinobu Ito, Takuya Ishimoto, Yusuke Tsutsumi, Takao Hanawa, Shiomi Sun and Takayoshi Nakano:
Control of Material Properties of Stainless Steel by Metal AM

〇Ryoya Suganuma, Takuya Ishimoto, Yoichi Takagishi, Tatsuya Yamagami and Takayoshi Nakano:
Thermal Diffusion Simulation for Control of Crystal Assembly Structure by Laser Stacking Method

〇Ryo Takehana, Aira Matsugaki, Kosuke Kawahara , Takafumi Ninomiya and Takayoshi Nakano:
Regulation of osteoblast and bone matrix orientation by laser-induced periodic surface structures

〇Tsubasa Todo, Takuya Ishimoto, Kouta Kimura, Gokcekaya Ozkan, Shinya Hibino, Toshishige Fujimitsu, Makoto Azuma, Kenichiro Igashira and Takayoshi Nakano:
Fabrication of Ni-based Superalloy by Metal Laser Stacking Process

〇Kana Nakano, Ryosuke Ozasa, Takuya Ishimoto, Aira Matsugaki, Takeshi Nagase, Mitsuharu Todai and Takayoshi Nakano:
Fabrication of BioHEA and formation of specific structures by laser stacking method

〇Fumihito Nakamura, Ryosuke Ozasa and Takayoshi Nakano:
Changes in bone microstructure and Young's modulus in pregnancy- and lactation-related osteoporosis

〇Ryo Fukushima, Takuya Ishimoto, Aira Matsugaki, Hiroshi Oji and Takayoshi Nakano:
Mechanisms of zinc-induced regulation of bone mechanics

〇Tadaaki Matsuzaka, Aira Matsugaki and Takayoshi Nakano:
Elucidation of the osteocyte-associated regulation of osteoblast alignment by constructing a stress-loaded anisotropic co-culture model

〇Shigeyuki Sakaki, Megumi Hasebe, Takuya Ishimoto and Takayoshi Nakano
Automatic Design of Bone Plate with Optimal Rotation Arrangement of Anisotropic Beta Titanium at Fuji Xerox

poster presentation

〇Shun Matsumoto, Aira Matsugaki, Takayoshi Nakano
Somatic cell sequence changes in response to macrophage activity

〇Naotaka Morita, Takuya Ishimoto, Kouta Kimura, Takayoshi Nakano:
Design of anisotropic function by hierarchical structure control using laser stacking method

〇Yusuke Yamaoka, Ryosuke Ozasa, Takayoshi Nakano:
Disruption of bone microstructure and physiological function in phosphorus metabolic failure

〇Kenji Tanaka, Makoto Wakabayashi, Aira Matsugaki, Seomi Son, Kouta Kimura, Takayoshi Nakano:
Regulation of mesenchymal stem cell alignment by material surface topography

〇Yuki Nishikawa, Takuya Ishimoto, Aira Matsugaki, Ryosuke Ozasa, Takeshi Nagase, Takayoshi Nakano:
Fabrication of High Entropy Alloys for Biomedical Applications by Laser Stacking Method

〇Ryohei Kamiyama, Hagiwara Koji, Yamazaki Michiaki, Kawamura Yoshihito, Nakano Takayoshi:
Mechanical properties of mille-feuille type Mg alloy single crystals

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The certificates of the three members of the Nakano Laboratory, who were awarded at the Japan Institute of Metals and Materials, have been sent to us.

○Takayoshi Nakano and Takuya Ishimoto: "Additive Manufacturing Process for Titanium and Titanium Alloys".
The 10th The Japan Institute of Metals and Materials The Best Paper Award

○Ryosuke Ozasa: "Mechanism of aggregate microstructure formation in hard tissues based on metallurgy
The 30th The Japan Institute of Metals and Materials Young Researcher Award

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A collaborate research paper with Prof. Narushima's lab at Tohoku University, which showed that microstructure control by metal AM improves the oxidation resistance of Cr was accepted for publication in Additive Manufacturing (Elsevier).

Ozkan Gokcekaya, Naohiro Hayashi, Takuya Ishimoto, Kyosuke Ueda, Takayuki Narushima, Takayoshi Nakano*:
Crystallographic orientation control of pure chromium via laser powder-bed fusion and improved high temperature oxidation resistance,
Additive Manufacturing, (2020), in press.

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Collaborate research with the Department of Pediatrics and Orthopedics, Jikei University School of Medicine has been accepted for publication in Molecular Therapy- Methods & Clinical Development as open access.

Miho Wada, Yohta Shimada, Sayoko Iizuka, Natsumi Ishii, Hiromi Hiraki, Toshiaki Tachibana, Kazuhiro Maeda, Mitsuru Saito, Shoutaro Arakawa, Takuya Ishimoto, Takayoshi Nakano, Hiroyuki Ida, Toya Ohashi, Hiroshi Kobayashi*:
Ex-vivo gene therapy treats bone complications of mucopolysaccharidosis type II mouse models through bone remodeling reactivation, Molecular Therapy- Methods & Clinical Development, (2020), in press.

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A paper showing that the inflammatory cytokine IL-6 reduces bone orientation has been published in the International Journal of Molecular Sciences.

Aira Matsugaki, Shun Matsumoto, Takayoshi Nakano*:
A novel role of interleukin-6 as a regulatory factor of inflammation-associated deterioration in osteoblast arrangement,
International Journal of Molecular Sciences, 21 [18], (2020), 6659: 1-11.
https://doi.org/10.3390/ijms21186659.

Click here to this paper.

Abstract
Inflammatory disorders are associated with bone destruction; that is, deterioration in bone cell activities are under the control of the innate immune system. Macrophages play a central role in innate immunity by switching their polarized phenotype. A disturbed immune system causes aberrance in the ordered bone matrix microarrangement, which is a dominant determinant of bone tissue functionalization. However, the precise relationship between the immune system and bone tissue organization is unknown. In this study, the controlled in vitro co-culture assay results showed that M1-polarized macrophages disrupted the osteoblast alignment, which directly modulate the oriented bone matrix organization, by secreting pro-inflammatory cytokines. Notably, interleukin-6 was found to be a key regulator of unidirectional osteoblast alignment. Our results demonstrated that inflammatory diseases triggered bone dysfunction by regulating the molecular interaction between the immune system and bone tissue organization. These findings may contribute to the development of therapeutic targets for inflammatory disorders, including rheumatoid arthritis.

Keywords: macrophage; osteoblast; cell arrangement; bone microstructure; interleukin-6

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Dr. Aira Matsugaki was nominated for the 2020 Science Award of the Japanese Society for Biomaterials.

Dr. Aira Matsugaki was selected for the 2020 Science Encouragement Award of the Japanese Society for Biomaterials.
The award ceremony and lecture will be held at Kansai University in November.

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A paper with the Osaka Prefecture University School of Veterinary Medicine on "Effects of stress shielding by custom-made plates on bone orientation in veterinary medicine" has been published as open access in PLoS ONE

Keiichiro Mie, Takuya Ishimoto, Mari Okamoto, Yasumasa Iimori, Kazuna Ashida, Karin Yoshizaki, Hidetaka Nishida, Takayoshi Nakano, Hideo Akiyoshi*:
Impaired bone quality characterized by apatite orientation under stress shielding following fixing of a fracture of the radius with a 3D printed Ti-6Al-4V custom-made bone plate in dogs,
PLoS ONE, 15(9), (2020), e0237678.
https://doi.org/10.1371/journal.pone.0237678

Click here to visit HP
Click here to PDF

Abstract
Custom-made implants have recently gained attention in veterinary medicine because of their ability to properly fit animal bones having a wide variety of shapes and sizes. The effect of custom-made implants on bone soundness and the regeneration process is not yet clear. We fabricated a 3D printed Ti-6Al-4V custom-made bone plate that fits the shape of the dog radius, and placed it into the radius where an osteotomy had been made. The preferential orientation of the apatite c-axis contributes to the mechanical integrity of the bone and is a reliable measure of bone quality. We determined this parameter as well as the bone shape and bone mineral density (BMD). The bone portion which lies parallel to the bone plate exhibited bone resorption, decreased BMD, and significant degradation of apatite orientation, relative to the portion outside the plate, at 7 months after the operation. This demonstrates the presence of stress shielding in which applied stress is not transmitted to bone due to the insertion of a stiff bone plate. This reduced stress condition clearly influences the bone regeneration process. The apatite orientation in the regenerated site remained different even after 7 months of regeneration, indicating insufficient mechanical function in the regenerated portion. This is the first study in which the apatite orientation and BMD of the radius were evaluated under conditions of stress shielding in dogs. Our results suggest that assessment of bone repair by radiography can indicate the degree of restoration of BMD, but not the apatite orientation.

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Four members of the Nakano Laboratory will be awarded the Japan Institute of Metals and Materials Prize in Autumn.

Since it is a Web site, there will be no award ceremony. However, Prof. Kosasa and Dr. Hibino will give the award lecture.

Ryosuke Ozasa: “Mechanism of aggregate microstructure formation in hard tissues based on metallic materials engineering”. The 30th The Japan Institute of Metals and Materials Young Researcher Award

Shinya Hibino (Kawasaki Heavy Industries, Ltd. & Nakano Lab., D1): “Development of grain boundary control technology for Ni-based heat-resistant alloys prepared by metal powder injection molding”. The 30th The Japan Institute of Metals and Materials Young Researcher Award

○Takayoshi Nakano and Takuya Ishimoto: “Additive Manufacturing Process for Titanium and Titanium Alloys”. The 10th The Japan Institute of Metals and Materials The Best Paper Award

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Today's Nikkan Kogyo Shimbun (Nikkan Kogyo Shimbun) carried an article on the joint research between Nakano Research Institute and AIST.

Bone density and structure reconstruction and development of a cellular scaffold
Nikkan Kogyo Shimbun, September 1, 2020, Morning Edition, page 20 (Science, Technology and University)
Click here for the electronic version.

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Dr. Nakano's column appeared in the morning edition of Nikkan Kogyo Shimbun today.

'We need to be flexible.'
Nikkan Kogyo Shimbun, August 24, 2020, morning edition, page 23 (Science and Technology, University)

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Dr. Pan Wang, who are active in Singapore, and Dr. Nakano have a special issue on Additive Manufacturing in MDPI's "Crystals" issue.

Everyone is welcome to contribute.

Special Issue "Additive Manufacturing: Materials, Processing, Characterization and Applications"

Special Issue Editors

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Dr. Pan Wang Website
Guest Editor
Scientist in Singapore Institute of Manufacturing Technology, 73 Nanyang Drive, 637662, Singapore
Interests: metal additive manufacturing; high-performance metallic powder; design and optimization of new structures; high-throughput microstructure analysis; phase transformation and deformation behavior

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Dr. Takayoshi Nakano Website SciProfiles
Co-Guest Editor
Distinguished Professor in Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
Interests: metal additive manufacturing with the heat source of laser or electron beam; crystallographic texture control, Crystal growth; anistotropic/ isotropic properties; Biocompatibility; Biomaterial & Aerospace applications

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Dr. Jiaming Bai Website
Co-Guest Editor
Assistant Professor in Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
Interests: additive manufacturing, nanocomposites, ceramics, functional structures

Click here for more information.

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The results of collaborate research with Niigata University of Medicine, Fukushima Medical University and Oita University of Nursing Science on the inhibitory effect of Type-I Angiotensin II receptor blockade on uremic bone mineral deterioration have been

Takuya Wakamatsu, Yoshiko Iwasaki, Suguru Yamamoto, Koji Matsuo, Shin Goto, Ichiei Narita, Junichiro J. Kazama*, Kennichi Tanaka, Akemi Ito, Ryosuke Ozasa, Takayoshi Nakano, Chisato Miyakoshi, Yoshihiro Onishi, Shingo Fukuma, Shunichi Fukuhara, Hideyuki Yamato, Masafumi Fukagawa, Tadao Akizawa:
Type-I Angiotensin II Receptor Blockade Reduces Uremia-induced Deterioration of Bone Material Properties,
Journal of Bone and Mineral Research (JBMR), (2020), online.
https://doi.org/10.1002/jbmr.4159

Click here for this paper
Click here for this PDF

Abstract
Chronic kidney disease (CKD) is associated with a high incidence of fractures. However, the pathophysiology of this disease is not fully understood, and limited therapeutic interventions are available. This study aimed to determine the impact of type‐1 angiotensin II receptor blockade (AT‐1RB) on preventing CKD‐related fragility fractures and elucidate its pharmacological mechanisms. AT‐1RB use was associated with a lower risk of hospitalization due to fractures in 3276 patients undergoing maintenance hemodialysis. In nephrectomized rats, administration of olmesartan suppressed osteocyte apoptosis, skeletal pentosidine accumulation and apatite disorientation, and partially inhibited the progression of the bone elastic mechanical properties, while the bone mass unchanged. Olmesartan suppressed angiotensin II‐dependent oxidation stress and apoptosis in primary cultured osteocytes in vitro. In conclusion, angiotensin II‐dependent intraskeletal oxidation stress deteriorated the bone elastic mechanical properties by promoting osteocyte apoptosis and pentosidine accumulation. Thus, AT‐1RB contributes to the underlying pathogenesis of abnormal bone quality in the setting of CKD, possibly by oxidative stress.

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A collaborative research paper with Prof. Niinomi was published in Journal of Materials Engineering and Performance.

Qiang Li*, Ran Zhang, Junjie Li, Qiang Qi, Xuyan Liu, Masaaki Nakai, Mitsuo Niinomi*, Takayoshi Nakano: Microstructure, Mechanical Properties, and Springback of Ti-Nb Alloys Modified by Mo Addition,
Journal of Materials Engineering and Performance, (2020), online.
https://doi.org/10.1007/s11665-020-05000-8

Click here for the paper

Abstract
A series of Ti-(38-2x)Nb-xMo (wt.%) alloys are designed using 1% Mo to replace 2% Nb in order to gradually increase the β stability and obtain a low springback. The α″ phase is exhibited in Ti-38Nb and suppressed with an increasing Mo content. The Ti-38Nb and Ti-34Nb-2Mo alloys show stress-induced α″ martensite transformations during cold rolling and double yielding behavior in tensile tests. The Ti-30Nb-4Mo and Ti-26Nb-6Mo alloys exhibit nonlinear deformation owing to the metastable β phase. With an increase in the Mo content, Young’s modulus increases slightly from 68 GPa in Ti-38Nb to 73 GPa in Ti-26Nb-6Mo, owing to the increase in β stability. Mo shows a solution strengthening effect that gradually increases the tensile strength. Although a higher Young’s modulus was not observed to be induced through deformation in Ti-(38-2x)Nb-xMo alloys, low springback was obtained according to the three-point bending loading–unloading test. In particular, the Ti-38Nb and Ti-34Nb-2Mo alloys with stress-induced α″ martensite transformations exhibit low yielding stress and are thus easily deformed. The deformed α″ phase hardly reverts to the β matrix after unloading, and therefore, the plastic deformation is maintained.

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Our paper has been published in Journal of Biomedical Materials Research A as open access.

Sungho Lee*, Fukue Nagata, Katsuya Kato, Toshihiro Kasuga, Takayoshi Nakano*:
Development of orthophosphosilicate glass/poly(lactic acid) composite anisotropic scaffolds for simultaneous reconstruction of bone quality and quantity,
Journal of Biomedical Materials Research A, (2020),
DOI: https://doi.org/10.1002/jbm.a.37067

Click here for this paper
Click here for this PDF

Abstract
Reconstruction of organ‐specific architecture is necessary to recover the original organ function. The anisotropic structure of bone tissue is strongly related to the collagen fibril alignment and bone apatite crystal direction. Bone regeneration indicates following two main process; first, restoration of bone mineral density (BMD; bone quantity), and second, restoring bone apatite c ‐axis orientation (bone quality). In addition to BMD, bone quality is the most important factor among bone mechanical properties. Recovery of the original bone function requires development of novel scaffolds with simultaneous reconstruction of bone quality and quantity. Herein, novel orthophosphosilicate glass (PSG)/poly(lactic acid) composite anisotropic scaffolds were developed to control cell alignment and enhance bone formation, which are important for the simultaneous reconstruction of bone quality and quantity. The strategy to control cell alignment and bone formation involved designing anisotropic scaffolds in combination with the release of therapeutic ions by PSGs. The morphology of fibrous scaffolds containing PSGs was quantitatively designed using electrospinning. This successfully modulated cell alignment and subsequent bone apatite c ‐axis orientation along the fiber‐oriented direction. The released silicate and Mg2+ ions from PSGs in scaffolds improved cell adhesion, proliferation, and calcification. To best of our knowledge, this is the first report demonstrating that the anisotropic scaffolds containing bioactive glasses regenerate bone tissues with simultaneous reconstruction of bone quality and quantity via stimulating osteoblasts by inorganic ions and designing morphology of scaffolds.

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Nikkan Kogyo Shimbun (Nikkan Kogyo Shimbun) published an article on the collaboration between the Kinki Bureau of Economy, Trade and Industry and the Anisotropic Custom Design and AM Research and Development Center (Director: Prof. Nakano) of the Graduate

Verification of the introduction of 3D printer - 37 companies selected as models for the Kinki Bureau of Economy, Trade and Industry
Nikkan Kogyo Shimbun, August 6, 2020, Morning Edition, page 31
Click here for this article
Click here for the press release from the Kinki Bureau of Economy, Trade and Industry

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A paper on the effect of stress shielding on bone orientation in veterinary medicine with the Osaka Prefecture University of Veterinary Medicine was accepted for publication in PLos one.

Keiichiro Mie, Takuya Ishimoto, Mari Okamoto, Yasumasa Iimori, Kazuna Ashida , Karin Yoshizaki, Hidetaka Nishida, Takayoshi Nakano, Hideo Akiyoshi*:
Impaired bone quality characterized by apatite orientation under stress shielding following fixing of a fracture of the radius with a 3D printed Ti-6Al-4V custom-made bone plate in dogs,
PLos one, (2020), in press.

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An article on joint research between Nakano Lab and Atlee Ltd. appeared on the front page of Nikkan Kogyo Shimbun.

Osaka University creates "mini-bone" that can be used for regenerative medicine:
Nikkan Kogyo Shimbun, July 31, 2020, morning edition, front page (top article)
Click here for the article
Click here for a PDF of the article

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A commentary written by Dr. Nakano appeared in the July issue of Special Steel.

Nakano Takayoshi:
Development trends in titanium and titanium alloys, and
Special Steels, Special Issue / Easy Commentary on Titanium and Titanium Alloys, 69 [4] (July), (2020), 39-42.
Click here for this PDF.

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A paper on the atomic structure analysis of antimicrobial beta-tricalcium phosphate has been published as open access in Nanoscale.

Ozkan Gokcekaya*, Kyosuke Ueda, Takayuki Narushima, Takayoshi Nakano:
Using HAADF-STEM for atomic-scale evaluation of incorporation of antibacterial Ag atoms in a β-tricalcium phosphate structure,
Nanoscale, (2020) in press.

Click here for the paper.
Click here for this PDF.

Abstract
Structural evaluation of ionic additions in calcium phosphates that enhance their performance is a long-lasting area of research in the field of biomedical materials. Ionic incorporation in β-tricalcium phosphate (β-TCP) structure is indispensable for obtaining desirable properties for specific functions and applications. Owing to its complex structure and beam-sensitive nature, determining the extent of ion incorporation and its corresponding location in the β-TCP structure is challenging. Further, very few experimental studies have been able to estimate the location of Ag atoms incorporated in a β-TCP structure while considering the associated changes in lattice parameters. Although the incorporation alters the lattice parameters, the alteration is not significant enough for estimating the location of the incorporated Ag atoms. Here, Ag incorporation in a β-TCP structure was evaluated on atomic scale using scanning transmission electron microscopy (STEM). To the best of our knowledge, this is the first report to unambiguously determine the location of the incorporated Ag atoms in the β-TCP structure by comparing z-contrast profiles of the Ag and Ca atoms by combining the state-of-art STEM observations and STEM image simulations. The Ag incorporation in the Ca(4) sites of β-TCP, as estimated by the Rietveld refinement, was in good agreement with the high-angle annular dark-field STEM observations and the simulations of the location of Ag atoms for [001] and [010] zone axes.

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Professor Nakano's web lectures to high school students are available on video.

Click here for the web kecture.

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A collaboration research with Narushima Lab at Tohoku University has been accepted for publication in Nanoscale.

Ozkan Gokcekaya*, Kyosuke Ueda, Takayuki Narushima, Takayoshi Nakano:
Using HAADF-STEM for atomic-scale evaluation of incorporation of antibacterial Ag atoms in a β-tricalcium phosphate structure,
Nanoscale, (2020) in press.

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Research results on the development of stress-sensitive mini-oriented bones have been published as open access in the "International Journal of Bioprinting".

Aira Matsugaki, Tadaaki Matsuzaka, Ami Murakami, Pan Wang, Takayoshi Nakano:
Three-dimensional printing of anisotropic bone mimetic structure with controlled fluid flow stimuli for osteocytes: Flow orientation determines the elongation of dendrites,
International Journal of Bioprinting, 6(4), (2020), 293; pp.1-12.
DOI: 10.18063/ijb.v6i4.293.

Click here for this paper.
Click here for this PDF.

Abstract
Although three-dimensional (3D) bioprinting techniques enable the construction of various living tissues and organs, the generation of bone-like oriented microstructures with anisotropic texture remains a challenge. Inside the mineralized bone matrix, osteocytes play mechanosensing roles in an ordered manner with a well-developed lacunarcanaliculi system. Therefore, control of cellular arrangement and dendritic processes is indispensable for construction of artificially controlled 3D bone-mimetic architecture. Herein, we propose an innovative methodology to induce controlled arrangement of osteocyte dendritic processes using the laminated layer method of oriented collagen sheets, combined with a custom-made fluid flow stimuli system. Osteocyte dendritic processes showed elongation depending on the competitive directional relationship between flow and substrate. To the best of our knowledge, this study is the first to report the successful construction of the anisotropic bone-mimetic microstructure and further demonstrate that the dendritic process formation in osteocytes can be controlled with selective fluid flow stimuli, specifically by regulating focal adhesion. Our results demonstrate how osteocytes adapt to mechanical stimuli by optimizing the anisotropic maturation of dendritic cell processes.

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A commentary and a paper on Nakano Lab's research were published in the July 2020 issue of the Journal of Smart Process Society for Materials, Environment & Energy respectively.

[Commentary]
Matsugaki Aira, Nakano Takayoshi:
Development of biomaterials and their application to cell regulation, using 3D printing
Journal of Smart Process Society, Vol. 9, [4], (July 2020), pp164-168
[Paper]
Ken Cho, Hiroyuki Yasuda*, Mitsuyo Toudai, Minoru Ueda, Masao Takeyama, Takayoshi Nakano:.
Improvement of high temperature fatigue properties of TiAl alloy fabricated by electron beam stacked fabrication by hot isostatic pressing, by
Journal of Smart Process Society, Vol. 9, [4], (July 2020), pp180-184

Click here for this commentary
Click here for this paper

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Today's Nikkan Kogyo Shimbun (Nikkan Kogyo Shimbun) morning edition, page 5, featured an article by Dr. Nakano (claim: "Anisotropy" of nature for industrial use).

Claims: "Anisotropic" industrial use of the natural world
Nikkan Kogyo Shimbun, July 6, 2020, morning edition, page 5 Opinioin
Click here for the electronic version

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The paper published in BioHEA was selected as "Editor's Choice Articles".

Takeshi Nagase, Kiyoshi Mizuuchi, Takayoshi Nakano*:
Solidification Microstructures of the Ingots Obtained by Arc Melting and Cold Crucible Levitation Melting in TiNbTaZr Medium-Entropy Alloy and TiNbTaZrX (X = V, Mo, W) High-Entropy Alloys,
Entropy, 21(5), (2019) 483;
https://doi.org/10.3390/e21050483
Click here for this paper
Click here for "Editor's Choice Articles "

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The Biomaterials Subcommittee of the Committee on Materials Science and Engineering of the Science Council of Japan (Chairman: Prof. Kazunori Kataoka) has issued a proposal, "Construction of International Leading Research Center for Biomaterials" as the "

Click here to see the Building of an International Center of Excellence for Biomaterials
Click here for the recommendations of the Science Council of Japan for 2020

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A research of the two-phase separation of new BioHEAs (biological high entropy alloys) has been published in MDPI's "Crystals" as open access.

Takeshi Nagase, Mitsuharu Todai, Takayoshi Nakano*:
Liquid Phase Separation in Ag-Co-Cr-Fe-Mn-Ni, Co Cr-Cu-Fe-Mn-Ni and Co-Cr-Cu-Fe-Mn-Ni-B High Entropy Alloys for Biomedical Application,
Crystals, 10(6), (2020), 527; 1-20.
https://doi.org/10.3390/cryst10060527
Click here for this paper.
Click here for this PDF.

Abstract
The liquid phase separation (LPS) behavior in Co-Cr-based high-entropy alloys (HEAs) is an important target for the development of Co-Cr-based HEAs for metallic biomaterials (BioHEAs). The solidification microstructure in Ag-Co-Cr-Fe-Mn-Ni-Ag, Co-Cr-Cu-Fe-Mn-Ni-Cu, and Co-Cr-Cu-Fe-Mn-Ni-B HEAs, which were designed as the combination of the equiatomic CoCrFeMnNi with Ag, Cu, and the interstitial element of B, was investigated as the fundamental research of LPS in Co-Cr-based HEAs. Ingots of equiatomic AgCoCrFeMnNi, equiatomic CoCrCuFeMnNi, non-equiatomic CoCrCuxFeMnNi (x = 2, 3), and CoCrCuxFeMnNiB0.2 (x = 1, 2, 3) with a small amount of B were fabricated using the arc-melting process. A macroscopic phase-separated structure was observed in the ingots of the equiatomic AgCoCrFeMnNi and CoCrCuxFeMnNiB0.2 (x = 2, 3) HEAs. The addition of a small amount of B enhanced the LPS tendency in the Co-Cr-Fe-Mn-Ni-Cu HEAs. The LPS behavior was discussed through the heat of mixing and computer coupling of phase diagrams and thermochemistry (CALPHAD).

Keywords: high-entropy alloys; metallic biomaterials; BioHEAs; liquid phase separation; solidification; microstructure; CALPHAD

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Nakano lab's commentary on bone matrix orientation was published in the July issue of BIO Clinica.

Takayoshi Nakano, Takuya Ishimoto, Aira Matsugaki, Ryosuke Ozasa:
Bone Substrate Orientation as a Bone Quality Indicator, Clinical Topics
BIO Clinica, 35 [7], (2020), PP651-657 (PP61-67).
Click here for more information
Click here for this PDF

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Nakano Lab members participated in the 40th Annual Meeting of the Japanese Society For Bone Morphometry (paper version).

Dr. Nakano gave a symposium lecture.
The presentations are as follows

Symposium Lecture
Nakano Takayoshi
Bony Site-Dependent Bone Substrate Orientation and Bone Implant Alignment

Oral Presentation
○Ishimoto Takuya, Kawahara Keita, Matsugaki Aira, Ueoka Hiroshi, Nakano Takayoshi
Correlation between apatite orientation and osteocyte morphological anisotropy, in longitudinal bone

○Matsugaki Aira, Nakanishi Yohei, Nakano Takayoshi
Specific Orthogonal Bone Substrate Orientation by Nanoperiodic Surface Structures

○Ozasa Ryosuke, Sasaki Kyohei, Nakano Takayoshi
Changes in Bone Substrate Orientation and Young's Modulus in Atherosclerosis

○ Matsuzaka Tadaaki, Matsugaki Aila, Nakano Takayoshi
Elucidation of the mechanism of osteocyte-derived bone substrate orientation by constructing a stress-loaded anisotropic co-culture model

○Yamaoka Yusuke, Ozasa Ryosuke, Nakano Takayoshi
Bone Substrate Orientation and Altered Bone Strength in X-Chromose-Linked Hypolymphemic Rickets

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The hcp-Ti-based HEA developed at Nakano Lab was featured on the front page of Nikkan Kogyo Shimbun.

Realized with more than 5 elements such as HCP-structured titanium alloys, Osaka University, etc. 3D modeling view:
Nikkan Kogyo Shimbun, June 11, 2020, morning edition, front page (General 1, top article)
Click here for electronic version
Click here for NIkkan Kogyo Shimbun

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Matsuzaka Tadaaki(M1) was selected for the 40th Young Researcher Award of the Japanese Society For Bone Morphometry.

Matsuzaka Tadaaki:
Elucidation of osteocyte-initiated bone substrate orientation in a stress-loaded anisotropic co-culture model
(Co-researchers: Matsugaki Aira and Nakano Takayoshi)

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A paper on a high entropy alloy containing two anisotropic hcp structures developed at Nakano Laboratory has been published online as an open access article in Scripta Material.

Takeshi Nagase, Mitsuharu Todai, Takayoshi Nakano*:
Development of Ti–Zr–Hf–Y–La high-entropy alloys with dual hexagonal-close-packed structure,
Scripta Materialia, 186 (2020), pp.242-246.
Click here for this paper.

Highlights
•Ti–Zr–Hf–Y–La high-entropy alloys with dual hcp structure were developed.
•Ti–Zr–Hf-rich and Y-La-rich phases were formed.
•Equi-axis dendrite structure was observed in the central area of the ingot.
•Liquid phase separation and segregation formed the dual hcp structure.
•The alloy design was verified based on immiscibility.

Abstract
TiZrHfYLa0.2 high-entropy alloys (HEAs) with dual hexagonal-closed-packed (HCP) structures were designed based on the concept of liquid phase separation (LPS) and segregation for enhancing the immiscibility of the constituent elements. The LPS leads to a particular solidification microstructure on the free surface side and Cu-hearth contacted area in the ingots. The dual HCP structures with equi-axis Ti–Zr–Hf dendrite and Y-La-rich interdendrite were observed at most regions of the arc-melted ingots. The mixing enthalpy among the constituent elements and predicted phase diagrams constructed by the Materials Project were effective for the alloy design of the HEAs with dual HCP structures.

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The book "Development of Materials for 3D Printer and High Precision Modeling" was published by Gijyutsu Jyoho Kyokai Co.

Ozasa Ryosuke, Ishimoto Takuya, Nakano Takayoshi:
Development of functional additive manufacturing materials based on crystal orientation control by metal 3D printer, "Development of Materials for 3D Printer and High Precision of Fabrications,
Technical Information Association, (2020), pp. 445-454.
click here for more information

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A research revealing for the first time that osteocalcin (OCN) determines the c-axis orientation of apatite crystals to collagen fibers, in collaboration with Dr. Komori and others at Nagasaki University, has been published as open access in PLoS Getetics

Takeshi Moriishi, Ryosuke Ozasa, Takuya Ishimoto, Takayoshi Nakano, Tomoka Hasegawa, Toshihiro Miyazaki, Wenguang Liu, Ryo Fukuyama, Yuying Wang, Hisato Komori, Xin Qin, Norio Amizuka, Toshihisa Komori*:
Osteocalcin is necessary for the alignment of apatite crystallites, but not glucose metabolism, testosterone synthesis, or muscle mass,
PLoS Getetics, 16 [5], (2020), e1008586.
https://doi.org/10.1371/ journal.pgen.1008586
Click here for this paper
Click here for this PDF

Abstract
The strength of bone depends on bone quantity and quality. Osteocalcin (Ocn) is the most abundant noncollagenous protein in bone and is produced by osteoblasts. It has been previously claimed that Ocn inhibits bone formation and also functions as a hormone to regulate insulin secretion in the pancreas, testosterone synthesis in the testes, and muscle mass. We generated Ocn-deficient (Ocn–/–) mice by deleting Bglap and Bglap2. Analysis of Ocn–/–mice revealed that Ocn is not involved in the regulation of bone quantity, glucose metabolism, testosterone synthesis, or muscle mass. The orientation degree of collagen fibrils and size of biological apatite (BAp) crystallites in the c-axis were normal in the Ocn–/–bone. However, the crystallographic orientation of the BAp c-axis, which is normally parallel to collagen fibrils, was severely disrupted, resulting in reduced bone strength. These results demonstrate that Ocn is required for bone quality and strength by adjusting the alignment of BAp crystallites parallel to collagen fibrils; but it does not function as a hormone.

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The paper on JBMR(Journal of Bone and Mineral Research) about Bone Quality published in 2013 is open-access.

Takuya Ishimoto, Takayoshi Nakano*, Yukichi Umakoshi, Masaya Yamamoto, Yasuhiko Tabata:
Degree of Biological Apatite c-Axis Orientation Rather Than Bone Mineral Density Controls Mechanical Function in Bone Regenerated Using Recombinant Bone Morphogenetic Protein-2,
Journal of Bone and Mineral Research (JBMR), 28 [5], (2013), pp 1170–1179.
DOI: 10.1002/jbmr.1825
Click here for this paper.
Click here for this PDF.

ABSTRACT
The aim of the present study was to assess the bone regeneration process in defects introduced into rabbit long bones, which were regenerated with controlled release of recombinant bone morphogenetic protein-2 (rBMP-2). The orientation of the biological apatite (BAp) c-axis and bone mineral density (BMD) were compared as predictors of bone mechanical function. A 20-mm-long defect was introduced in rabbit ulnas, and 17 mg of rBMP-2 was controlled-released into the defect using a biodegradable gelatin hydrogel as the carrier. In the bone regeneration process, two characteristic phases may have been governed by different factors. First, new bone formation actively occurred, filling the bone defect with newly formed bone tissue and increasing the BMD. This process was regulated by the strong osteoinductive capacity of rBMP-2. Second, after filling of the defect and moderate BMD restoration, preferential BAp c-axis orientation began to increase, coincident with initiation of remodeling. In addition, the BAp c-axis orientation, rather than BMD, was strongly correlated with Young’s modulus, an important index of bone mechanical function, particularly in the later stage of bone regeneration. Thus, preferential BAp c-axis orientation is a strong determinant and predictor of the mechanical function of tissueengineered bone. Therefore, analysis of BAp preferential c-axis orientation in addition to measurement of BMD is crucial in assessment of bone mechanical function. Ⓒ2013 American Society for Bone and Mineral Research.

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We had a B4 welcome party at zoom!

We had a welcome party for B4, who was assigned to us in April at zoom.
We still have a ban on B4's attendance at school, but we're looking forward to the day when the restrictions are lifted and he can come to our lab!

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Prof. Tsutsumi published an article on "Improvement of Corrosion Resistance by Laser Additive Manufacturing" in Nikkan Kogyo Shimbun.

Stainless Steel - Expanding Applications by Demonstrating Corrosion Resistance: Stainless Steel
May 20, 2020, Nikkan Kogyo Shimbun morning edition, page 25 (Science and Technology, University)
Click here for this PDF

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The Nakano Lab's paper was selected as one of the "Top Downloaded Papers 2018-2019" by the Journal of Biomedical Materials Research Part A (JBMR-A), published by Wiley.

The Nakano Lab's paper was selected as one of the "Top Downloaded Papers 2018-2019" by the Journal of Biomedical Materials Research Part A (JBMR-A), published by Wiley.
Click here for certificate.

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Dr. Nakano received the Commendation and the medal for Awards for Science and Technology (Research Category) in 2020 by the Minister of Education, Culture, Sports, Science and Technology.

Nakano Takayoshi:
Research on materials science, anisotropic
Ministry of Education, Culture, Sports, Science and Technology, April 14, 2020

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Reasons for this award for "Research on Anisotropic Materials Science

Click here for the reasons
Click here for more information
Click here for the winners PDF
Click here for related articles on the Osaka University website

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A collaborate research with Toyosawa Lab at Osaka University's Graduate School of Dentistry was published online in Bone.

Katsutoshi Hirose, Takuya Ishimoto, Yu Usami, Sunao Sato, Kaori Oya, Takayoshi Nakano, Toshihisa Komori, Satoru Toyosawa*:
Overexpression of Fam20C in osteoblast in vivo leads to increased cortical bone formation and osteoclastic bone resorption,
Bone, 138, (2020) 115414; 1-15
https://doi.org/10.1016/j.bone.2020.115414

Click here for this paper

Abstract
Fam20C, which phosphorylates many secretory proteins with S-x-E/pS motifs, is highly expressed in bone and tooth tissues, implying that Fam20C-mediated phosphorylation is critical for regulation of these mineralized tissues. Previous studies of Fam20C-deficient mice revealed that Fam20C plays important roles in bone formation and mineralization. However, Fam20C-deficient mice develop hypophosphatemia, a systemic factor that masks the local effect of Fam20C in the bone tissue; consequently, the local role of Fam20C remains unknown. To elucidate the local function of Fam20C in bone tissue, we studied osteoblast-specific Fam20C transgenic (Fam20C-Tg) mice, which have no alteration in serum calcium and phosphate levels. Fam20C-Tg mice had more highly phosphorylated proteins in bone tissue than wild-type mice. In cortical bone of Fam20C-Tg mice, bone volume, mineralization surface (MS/BS), and mineral apposition rate (MAR) were elevated; in addition, the transgenic mice had an elevated number of vascular canals, resulting in an increased cortical porosity. Osteocyte number was elevated in the transgenics, but osteoblast number was unchanged. The microstructure of bone matrix characterized by the preferential orientation of collagen and apatite, was degraded and thus the mechanical function of bone material was deteriorated. In trabecular bone of Fam20C-Tg mice, bone volume was reduced, whereas MS/BS and MAR were unchanged. Osteoclast number was elevated and eroded surface area was non-significantly elevated with an increased serum CTX-I level, whereas osteoblast number was unchanged. These findings indicated that Fam20C overexpression in osteoblasts promotes cortical bone formation by increasing MS/BS and MAR and promoting osteocyte differentiation, but does not affect trabecular bone formation. Furthermore, Fam20C overexpression indirectly promotes osteoclastic bone resorption in cortical and trabecular bones. Our findings show that osteoblastic Fam20C-mediated phosphorylation in bone tissue regulates bone formation and resorption, and bone material quality.

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An article by Kondo Haruka, who participate in the Nakano laboratory in the SEEDS program last year, was published in "Materia".

Kondo Haruka:
My Life-Changing Experience: Unraveling the Relationship between High Blood Pressure and Bone, by
Matelian, 59 [5], (2020), pp. 269.
Click here for this PDF

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The article on "Development of Bone Formation Promoting Materials Using Bioactive Glasses" was published in Ceramics.

Sungho Lee, Toshihiro Kasuga and Takayoshi Nakano:
Development of osteopathic materials, using bioactive glasses to promote bone formation
Ceramics, 55 [3], (2020), pp. 150-154.

Click here for this PDF

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A collaborate research paper with Northeast University and Shanghai University was published online as open-access in the Journal of Materials Engineering and Performance.

Qiang Li , Chao Cheng, Junjie Li, Ke Zhang, Kai Zhou, Masaaki Nakai, Mitsuo Niinomi, Kenta Yamanaka, Daixiu Wei, Akihiko Chiba, Takayoshi Nakano:
Low Young‛s Modulus and High Strength Obtained in Ti-Nb-Zr-Cr Alloys by Optimizing Zr Content,
Journal of Materials Engineering and Performance, (2020) on line.
https://doi.org/10.1007/s11665-020-04826-6

Click here for this paper
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A commentary and a paper on the Nakano Lab's research will be published in the July 2020 issue of the Journal of the Smart Process Society, respectively.

[Commentary]
Aira Matsugaki, Takayoshi Nakano:
Development of biomaterials and their application to cell regulation, using 3D printing
Journal of Smart Process Society, Vol. 9, [4], (July 2020), pp164-168
[Paper]
Ken Cho, Hiroyuki Yasuda*, Mitsuyo Toudai, Minoru Ueda, Masao Takeyama, Takayoshi Nakano:.
Improvement of high temperature fatigue properties of TiAl alloy fabricated by electron beam stacked fabrication by hot isostatic pressing, by
Journal of Smart Process Society, Vol. 9, [4], (July 2020), pp180-184

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An article on the collaborate research with Professor Matsumoto of Okayama University was published in Nikkan Kogyo Shimbun newspaper.

Titanium for Metal Adhesives, for Bio-soft Tissue, Okayama University, etc.
Nikkan Kogyo Shimbun morning edition, page 23, April 24, 2020

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The book "High Entropy Alloys," which Professor Nakano co-authored, will be published.

Takayoshi Nakano (Contributing Writer).
High entropy alloys, "Chapter 6.2 Biomaterials",
Uchida rokakuen, Tokyo, (2020).
Click here for more book details

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An article about Prof. Nakano's award to the Minister of Education, Culture, Sports, Science and Technology appeared in the column of Nikkan Kogyo Shimbun.

"I'm upset with the conceptual assessment"
Nikkan Kogyo Shimbun, April 16, 2020, morning edition, page 23 (Science and Technology, University)

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Life Science/Nanotechnology and Materials field "Bone Aligning Agents and Therapeutics" was introduced in the Nakano Lab's Intellectual Property section.

T. Nakano, A. Matsugaki, T. Ishimoto, and R. Ozasa:
Bone Aligning Agents, Therapeutic Agents,
Life Science/Nanotechnology and Materials, pp. 47.
Click here for details.

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A photo of HEA alloys related to Nakano Lab's HEA alloys for biomedical use was published in the Branch Bulletin of the Kansai Branch of Japan Foundry Engineering Society, No. 7 (2020).

A photo of HEA alloys related to Nakano Lab's HEA alloys for biomedical use was published in the Branch Bulletin of the Kansai Branch of Japan Foundry Engineering Society, No. 7 (2020).

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Seven students (GUPTA MRIDUL, Kenji Tanaka, Yuki Nishikawa, Tomoya Hosokawa, Yasuhiro Masuda, Kouki Manabe, and Ryosei Miura) have been assigned to Nakano Lab as the new B4 students.

Now we have a new organization at Nakano Lab. Let's work together and do our best.

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Five students (Ryo Fukushima, Tadaaki Matsuzaka, Shun Matsumoto, Naotaka Morita, and Yusuke Yamaoka) from Nakano Lab have been assigned to the Nakano Lab as M1 students.

We look forward to working with you as the core of the Nakano Lab.

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A paper showing that cell and substrate orientation can be achieved by electrospinning fine lines has been published in RSC Advances.

Sungho Lee*, Fukue Nagata, Katsuya Kato, Takayoshi Nakano*:
Bone apatite anisotropic structure control via designing fibrous scaffolds,
RSC Advances, 10, (2020), 13500–13506, DOI: 10.1039/d0ra01295e.

Click here for this paper
Click here for this PDF

Abstract
Bone tissue has an anisotropic structure, associated with the collagen fibrils' orientation and the c-axis direction of the bone apatite crystal. The bone regeneration process comprises two main phases: bone mineral density restoration (bone quantity), and subsequent recovery of bone apatite c-axis orientation (bone quality). Bone quality is the determinant factor for mechanical properties of bone. Control of osteoblast alignment is one of the strategies for reconstructing bone quality since the collagen/apatite matrix orientation in calcified tissues is dependent on the osteoblast orientation. In this work, fibrous scaffolds designed for reconstruction of bone quality via cell alignment control was investigated. The fibrous scaffolds were fabricated using the electrospinning method with poly(lactic acid) at various fiber collecting speeds. The degree of fiber alignment in the prepared fibrous scaffolds increased with increasing fiber collecting speed, indicating that the fibers were oriented in a single direction. The alignment of osteoblasts on the fibrous scaffolds as well as the subsequent apatite c-axis orientation increased with increasing fiber collecting speed. We successfully controlled cell alignment and apatite c-axis orientation using the designed morphology of fibrous scaffolds. To the best of our knowledge, this is the first report demonstrating that adjusting the degree of fiber orientation for fibrous scaffolds can manipulate the regeneration of bone quality.

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Dr. Nakano has been appointed Director of the Anisotropic Custom Design and AM Research and Development Center, Graduate School of Engineering, Osaka University.

Dr. Nakano has been appointed Director of the Anisotropic Custom Design and AM Research and Development Center, Graduate School of Engineering, Osaka University.

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Shinya Hibino and Sung-Hyun Park have joined Nakano Lab as doctoral students.

Shinya Hibino and Sung-Hyun Park have joined Nakano Lab as doctoral students.

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The results of the adoption of the Grant-in-Aid for Scientific Research are now available. Dr. Matsugaki was selected for basic research (A), Dr. Ozasa for young researchers and continuing research, Dr. Nakano for basic research (S), and Dr. Ishimoto for

[New Subject (as Principal Investigator)]
Aira Matsugaki: Grants-in-Aid for Scientific Research (A),
"Elucidating the Mechanism of Bone Dysfunction in Cancer Metastasis - Towards Innovative 'Osteo-Oriented Cancer Treatment',
2020~ 2023, total direct costs 34,300 thousand yen (total costs 44,590 thousand yen)

Ryosuke Ozasa: Grant-in-Aid for Young Scientists,
The mechanism of bone strength control by Cu as a bio-trace metal element based on materials engineering methods,
2020~ 2021, total direct costs 3.3 million yen (total costs 4.29 million yen)

[Continuing Issues (as Principal Investigator)]
Takayoshi Nakano: Grants-in-Aid for Scientific Research (S),
Building 'Anisotropic Materials Science' for Induction of Bone Anisotropy,
2018- 2022, total direct costs 148,800 thousand yen (total costs 193,440 thousand yen)

Takuya Ishimoto: Grant-in-Aid for Scientific Research (A),
New Bone Functionalization Implantology without Bone Degradation,
2019- 2022, total direct costs 34,600 thousand yen (total costs 44,980 thousand yen)

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Today was the graduation ceremony.

Although it was a commemorative photo outdoors for COVID19, six master's and seven undergraduate students at Nakano Lab have left our lab.
I am confident that they will make a great leap forward.

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Research on "Development of Soft Tissue Adhesion Ti Materials", a collaborate research with Prof. Matsumoto of Graduate School of Medical and Dental Sciences, Okayama University, has been published in "Advanced Materials Interfaces".

Masahiro Okada, Emilio Satoshi Hara, Atsushi Yabe, Kei Okada, Yo Shibata, Yasuhiro Torii, Takayoshi Nakano, Takuya Matsumoto:
Titanium as an Instant Adhesive for Biological Soft Tissue,
Advanced Materials Interfaces, (2020), pp.192089(1-7)
https://doi.org/10.1002/admi.201902089.

Click here for this paper
Click here for this PDF

Abstract
A variety of polymer- and ceramic-based soft-tissue adhesives have been developed as alternatives to surgical sutures, yet several disadvantages regarding the mechanical properties, biocompatibility, and handling hinder their further application particularly when applied for immobilization of implantable devices. Here, it is reported that a biocompatible and tough metal, titanium (Ti), shows instant and remarkable adhesion properties after acid treatment, demonstrated by ex vivo shear adhesion tests with mouse dermal tissues. Importantly, in vivo experiments demonstrate that the acidtreated Ti can easily and stably immobilize a device implanted in the mouse subcutaneous tissue. Collectively, the acid-treated Ti is shown as a solid-state instant adhesive material for biological soft tissues, which can have diverse applications including immobilization of body-implantable devices.

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The project of Metal AM Center was introduced in Nikkan Kogyo Shimbun.

Metal 3D Additive Manufacturing, Improving Competitiveness of Enterprises, Osaka University Supports Nationwide, Fostering Engineers to Realize High Value-Added Products
Nikkan Kogyo Shimbun, March 23, 2020, Morning Edition, page 30 (Science and Technology, University)
Click here for this PDF
Click here for this JPEG

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The Nikkei Sangyo Shimbun introduced the importance of Nakano Lab's concept of "Anisotropic Materials Science".

Crystals, alignment control, "anisotropy" of materials, and high performance
Nikkei Sangyo Shimbun morning edition, March 23, 2020, page 6
Click here for this PDF
Click here for this JPEG

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A collaborate research with Tokyo Dental University has been published in JBMR-B. The effect of muscle on human jawbone apatite.

Masaaki Kasahara, Satoru Matsunaga, Tomoko Someya, Kei Kitamura, Kento Odaka, Takuya Ishimoto, Takayoshi Nakano, Shinichi Abe, Masayuki Hattori:
Micro- and nano-bone analyses of the human mandible coronoid process and tendon-bone enthuses,
JBMR-B, (2020)
DOI: 10.1002/jbm.b.34609

Click here for this paper
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Dr. Ishimoto was awarded the 78th The Japan Institute of Metals and Materials Meritorious Award.

Ishimoto Takuya:
Elucidation of bone function based on metal engineering and creation of bone biomaterials,
78th The Japan Institute of Metals and Materials Meritorious Award, March 17, 2020.

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The September 2019 issue of Materials Transactions is now open access.

We have four related papers.

Takayoshi Nakano, Takayuki Narushima, Takao Hanawa, Masato Ueda, Yoko Yamabe-Mitarai, Tadashi Furuhara, Hideki Hosoda, Mitsuo Niinomi:
Preface,
Materials Transactions, 60 [9], (2019), 1732,
https://doi.org/10.2320/matertrans.MPR2019906.

M. Niinomi, T. Akahori, M. Nakai, Y. Koizumi, A. Chiba, T. Nakano, T. Kakeshita, Y. Yamabe-Mitarai, S. Kuroda, N. Motohashi, Y. Itsumi, T. Choda:
Quantitative and Qualitative Relationship between Microstructural Factors and Fatigue Lives under Load- and Strain-Controlled Conditions of Ti-5Al-2Sn-2Zr-4Cr-4Mo (Ti-17) Fabricated Using a 1500-ton Forging Simulator,
Materials Transactions, 60 [9]. (2019), 1740-1748,
https://doi.org/10.2320/matertrans.ME201904.

Qiang Li, Qiang Qi, Junjie Li, Masaaki Nakai, Mitsuo Niinomi, Yuichiro Koizumi, Daixiu Wei, Kenta Yamanaka, Takayoshi Nakano, Akihiko Chiba, Xuyan Liu, Deng Pan:
Low Springback and Low Young's Modulus in Ti-29Nb-13Ta-4.6Zr Alloy Modified by Mo Addition,
Materials Transactions, 60 [9]. (2019), 1755-1762,
https://doi.org/10.2320/matertrans.ME201912.

Qiang Li, Xufeng Yuan, Junjie Li, Pan Wang, Masaaki Nakai, Mitsuo Niinomi, Takayoshi Nakano, Akihiko Chiba, Xuyan Liu, Deng Pan:
Effects of Fe on Microstructures and Mechanical Properties of Ti-15Nb-25Zr-(0, 2, 4, 8)Fe Alloys Prepared by Spark Plasma Sintering,
Materials Transactions, 60 [9]. (2019), 1763-176.
https://doi.org/10.2320/matertrans.ME201913.

Sungho Lee, Jong Yeong Oh, Soichiro Mukaeyama, Shi-Hai Sun, Takayoshi Nakano:
Preparation of Titanium Alloy/Bioactive Glass Composite for Biomedical Applications via Selective Laser Melting,
Materials Transactions, 60 [9]. (2019), 1779-1784.
DOI https://doi.org/10.2320/matertrans.ME201914

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A paper on the diversity of microstructural control by laser 3D printing (SLM) in SUS316L stainless steel was published on line as an open access paper in ISIJ International.

Takuya Ishimoto, Siqi Wu, Yukinobu Ito, Shi-Hai Sun, Hiroki Amano, Takayoshi Nakano*:
Crystallographic Orientation Control of 316L Austenitic Stainless Steel via Selective Laser Melting,
ISIJ International, (2020), on line
DOI: https://doi.org/10.2355/isijinternational.ISIJINT-2019-744.

Click here for this paper.
Click here for this PDF.

【Absract】
In recent years, additive manufacturing has attracted attention as a technology that enables control of the crystallographic texture of metallic materials. We achieved successful control of the crystallographic texture of 316L austenitic stainless steel using selective laser melting (SLM). Three distinguished textures were achieved by changing the laser scan speed, namely: the single crystalline-like texture with {001} orientation in the build direction, the crystallographic lamellar texture in which two kinds of grains with {011} and {001} orientations in the build direction are alternately stacked, and polycrystalline with relatively random orientation. The melt pool shape and the solidification behavior (thermal gradient and migration velocity of solid/liquid interface) in a melt pool could be important controlling factors for the evolution of the crystallographic texture under the SLM process.

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The Nihon Keizai Shimbun newspaper carried an article that showed that "Use of Metal 3D Printer Improves Performance of Stainless Steel," which was headlined by our laboratory.

Takuya Ishimoto, Takayoshi Nakano:
Utilizing 3D Printers, Improving the Performance of Metal Materials
Nihon Keizai Shimbun, Science and Technology, page 11, March 2, 2020

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A commentary on our 316L stainless steel was published in the February issue of the Journal of Japan Laser Processing Society.

Takuya Ishimoto, Takayoshi Nakano:
Microstructure control and enhancement of 316L stainless steel, by laser lamination molding
Journal of the Laser Society, 27 [1], (2020), pp.61-63

Click here for this PDF

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A paper on rat tail-suspension-induced hypo-orientation was published in Dental Materials Journal.

Kosuke Nakajima, Satoru Matsunaga*, Toshiyuki Morioka, Takayoshi Nakano, Shinichi Abe, Yoshitaka Furuya, Yasutomo Yajima:
Effects of unloading by tail suspension on biological apatite crystallite alignment in mouse femur,
Dental Materials Journal, (2020), on line.
https://doi.org/10.4012/dmj.2019-187
Article ID: 2019-187, Published: 2020
[Advance publication] Released: February 07, 2020.

Click here for this paper.
Click here for this PDF.

Abstract
The aim of this study was clarify the effects of reducing various functional pressures essential for the maintenance of bone homeostasis. Femoral bone mineral density (BMD) and biological apatite (BAp) crystallite alignment were measured in conventionally reared and hindlimb-unloaded mice. The femur was divided into 10 equal segments perpendicular to the longitudinal axis of the bone and measurements were performed on the cortical bone in the five segments closest to the midpoint of the femur. Significantly lower BMD and BAp alignment in the longitudinal (Z-axis) direction were observed in the hindlimb-unloaded group. The present findings suggest that unloading by tail suspension significantly decreases not only mouse femoral bone mass but also BAp crystallite alignment, although minimal uniaxial preferential alignment is retained.

In addition, please read the following article previously published.

Jun Wang, Takuya Ishimoto, Takayoshi Nakano*:
Unloading-Induced Degradation of the Anisotropic Arrangement of Collagen/Apatite in Rat Femurs,
Calcif Tissue Int, 100 (2017) 87–94.

Click here for this paper.
Click here for this PDF.

Abstract
The specific orientation of collagen and biological apatite (BAp) is an anisotropic feature of bone micro-organization; it is an important determinant of bone mechanical function and performance under anisotropic stress. However, it is poorly understood how this microstructure orientation is altered when the mechanical environment changes. We hypothesized that the preferential orientation of collagen/BAp would change in response to changes in mechanical conditions, similar to the manner in which bone mass and bone shape change. In the present study, we investigated the effect of unloading (removal of anisotropic stress) on the preferential orientation of collagen/BAp using a rat sciatic neurectomy model. Bone tissue that formed under unloaded conditions showed a more disordered collagen/BAp orientation than bone tissue that formed under physiological conditions. Coincidentally, osteocytes in unloaded bone displayed spherical morphology and random alignment. To the best of our knowledge, this study is the first to demonstrate the degradation of preferential collagen/BAp orientation in response to unloading conditions. In summary, we identified alterations in bone material anisotropy as an important aspect of the bone’s response to unloading, which had previously been examined with regard to bone loss only.

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Today's Nikkan Kogyo Shimbun (Nikkan Kogyo Shimbun) carried an article on the "Subsidy for Regional New Growth Industry Creation Project (Regional Future Open Innovation Platform Construction Project)" by the Ministry of Economy, Trade and Industry, led b

"Competitiveness in Metal 3D Modeling
Utilizing the latest equipment, Han University and the Bureau of Economy, Trade and Industry of Kinki
Nikkan Kogyo Shimbun morning edition, page 29, February 6, 2020.

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The January issue of Titanium magazine published an article on the research report of the Nakano Lab.

This paper deals with the design and development of bcc-type high entropy alloys for biomedical applications.

Mitsuharu Toudai, Takeshi Nagase, Takayoshi Nakano:
Design and development of a biocompatible biological bcc high entropy alloy, comparable to pure titanium,
Titanium, 68 [1], January, (2020),pp.59-63

Click here for this PDF

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A paper on HEA alloys based on Co-Cr-Mo alloys has been published in the journal Materials Transactions for early publication.

Takeshi Nagase, Mitsuharu Todai, Takayoshi Nakano*:
Development of Co-Cr-Mo-Fe-Mn-W and Co-Cr-Mo-Fe-Mn-W-Ag High-Entropy Alloys Based on Co-Cr-Mo Alloys,
Materials Transactions, (2020) Advance View.
Click here for this PDF.

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Today's Nikkan Kogyo Shimbun features the results of our collaborate research with Dr. Ameyama, Ritsumeikan University,

"Alloys for Compatible and Strong Implants",
Nikkan Kogyo Shimbun morning edition, page 35 (Science and Technology, University), January 29, 2020.

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The January issue of the Journal of the Japan Institute of Light Metals published a commentary by our laboratory on HEA alloys.

Mitsuharu Todai, Takeshi Nagase, Takayoshi Nakano:
Development and Prospects for High Entropy Alloys Containing Light Metal Elements and BCC-Type High Entropy Alloys for Biological Use, by
Journal of the Light Metal Society, 70 [1], (2020), pp. 14-23.

Click here for this PDF.

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Dr. Nakano's commentary on the AM project was published in the January issue of the Journal of Japan Welding Society.

Nakano Takayoshi:
SIP Phase 1 and 2: New Growth Industry Creation Promotion Project by the Ministry of Economy, Trade and Industry: Control of Material Structure and Atomic Arrangement by Laser Metal Additive Manufacturing,
Journal of Japan Welding Society, 89 [1], (2020), 27-37.

Click here for this article.

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Today's Nikkan Kogyo Shimbun reports the results of our collaborate research with Tokyo Dental University.

Tokyo Dental University and Osaka University, elucidating the structure of the lower jawbone, a way to treat diseases,
January 14, 2020, Nikkan Kogyo Shimbun morning edition, page 23 (Science and University).

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Dr. Nakano gave an invited lecture at the 2019 Fall Joint Conference (99th Japanese Society of Veterinary Anesthesia and surgery, 111th Annual Meeting of the Japanese Society of Veterinary Cardiology, and 66th Annual Meeting of the Japanese Society of Ve

Takayoshi Takayoshi:
Orientation of apatite/collagen as a new bone quality indicator and its application to bone regeneration medicine, including metal 3D printers,
Saturday, January 11, 2020, 9:00-10:00, Osaka International House, Hall 9 (Large Hall 1F).

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A scene in the lecture

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With the conference keynote speakers (from left, President Sasai, Dr. Tsumaki, Dr. Nakano, Dr. Kuroda, and Dr. Nishida)

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A reunion with Dr. Hatota, a graduate who became a veterinarian, after a long absence. (From left, Dr. Hatota, Dr. Sasai, and Dr. Nakano)

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Dr. Nakano addresses the audience before the toast at the information exchange

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2019

A paper on apatite macro-nanostructure in rat masseter muscle in collaboration with Tokyo Dental University has been published in the Journal of hard tissue biology as an open access journal.

Keitaro Arakawa, Satoru Matsunaga, Kunihiko Nojima, Takayoshi Nakano, Shinichi Abe, Masao Yoshinari, Kenji Sueishi:
Micro- and nanostructural characteristics of rat masseter muscle enthuses,
Journal of hard tissue biology, 28 [4], (2019), 365-370.
https://doi.org/10.2485/jhtb.28.365

Abstract
The entheses of the masticatory muscles differ slightly from those of the trunk and limb muscles. However, the bones of the skull are subject to various functional pressures, including masticatory force, resulting in a complex relationship between bone structure and muscle function that remains to be fully elucidated. The present study aimed to clarify aspects of masseter muscle-tendon-bone morphological characteristics and local load environment through quantitative analysis of biological apatite (BAp) crystallite alignment and collagen fiber orientation together with histological examination of the entheses. Result of histological observation, the present findings show that, in the entheses of the masseter muscle in the first molar region, tendon attaches to bone via unmineralized fibrocartilage, while some tendon collagen fibers insert directly into the bone, running parallel to the muscle fibers. Furthermore, BAp crystallites in the same region show uniaxial preferential alignment at an angle that matches the insertion angle of the tendon fibers. Conversely, in the entheses of the masseter muscle in the third molar region, the tendon attaches to the bone via a layer of thickened periosteum and chondrocytes. As in the first molar region, the results of bone quality analysis in the third molar region showed BAp crystallite alignment parallel to the orientation of the tendon fibers. This indicates that the local mechanical environment generates differences in enthesis morphology. The present study showed a greater degree of uniaxial BAp crystallite alignment in entheses with direct insertion rather than indirect tendon-bone attachment and the direction of alignment was parallel to the orientation of tendon fibers. These findings suggest that functional pressure from the masseter muscle greatly affects bone quality as well as the morphological characteristics of the enthesis, specifically causing micro- and nanostructural

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Two papers on Nakano Lab have been published for early publication in Materials Transactions.

Ryosuke Ozasa, Mayuko Nakatsu, Atsushi Moriguchi, Kyohei Sasaki, Takuya Ishimoto, Masahiro Okada, Takuya Matsumoto, Takayoshi Nakano*:
Analysis of Bone Regeneration Based on the Relationship between the Orientations of Collagen and Apatite in Mouse Femur,
Materials Transactions, (2019) Advance View,
https://doi.org/10.2320/matertrans.MT-M2019341
Click here for this PDF.

Koji Hagihara*, Takuya Okamoto, Ryohei Ueyama, Michiaki Yamasaki, Yoshihito Kawamura, Takayoshi Nakano:
Loading Orientation Dependence of the Formation Behavior of Deformation Kink Bands in the Mg-Based Long-Period Stacking Ordered (LPSO) Phase,
Materials Transactions, (2019) Advance View,
https://doi.org/10.2320/matertrans.MT-MM2019001
Click here for this PDF.

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We visited Hitachi Metals GRIT and Dr. Nakano gave a lecture.

Nakano Takayoshi:
Functionalization by control of materials, including internal shape and atomic arrangement, using metal AM

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Dr. Nakano gave a special lecture at the 1st Design Sharing Conference (SIP Design Sharing).

Takayoshi Nakano:
SIP Phase 1 / Innovative Design and Production Technologies (Sasagusugi PD) for SIP Phase 2 / Materials for Life through Integrated Materials Development System (Mishima PD), by Takayoshi Nakano,
Special Lecture II, December 12, 2019, at the main conference room of the East Office of the National Research and Development Institute

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An international collaborative study published in Biomaterials Science showed that the ONO-1301-doped nanocomposite modulates cAMP-mediated signaling and induces new bone formation in critical-sized bone defects.

Shruthy Kuttappan, Jun-ichiro Jo, Deepthy Menon Takuya Ishimoto, Takayoshi Nakano, Shantikumar Nair, Yasuhiko Tabata, Manitha Nair*:
ONO-1301 loaded nanocomposite scaffold modulates cAMP mediated signaling and induce new bone formation in critical sized bone defect,
Biomaterials Science, (2019).
DOI: 10.1039/C9BM01352K

Click here for this PDF.

Abstract
Recent studies on bone regeneration demonstrate the use of low cost and stable small molecules, which avoid the adverse effect and high cost of growth factors. Herein, we investigate the chemotactic, angiogenic and osteoinductive potential of a prostacyclin analogue, ONO-1301, when delivered through a biomimetic nanocomposite scaffold (nanohydroxyapatite–gelatin matrix reinforced with fibers) for bone tissue regeneration. The small molecule was loaded onto the scaffold in three different concentrations. There was burst release from all the groups of scaffolds within 24 h followed by a sustained release up to 14 days, but the concentration was dependent on loading percentage. ONO-1301 loaded scaffolds augmented the migration, proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs), but increasing the concentration beyond a certain dose did not show any effect. The osteoinduction was mediated through the prostaglandin I2 receptor and cyclic AMP (cAMP) signaling pathway. They also promoted new bone formation in large sized calvarial defects in rats compared to the scaffold alone, but did not show any impact on angiogenesis. Hence, this study suggests the chemotactic and osteoinductive capability of ONO-1301 for the repair and regeneration of critical sized bone defects.

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Mr. Amano won the best poster award, and Mr. Ito, Mr. Suganuma, and Mr. Nakano of M1 won the best poster award at the 2nd Meeting of the Japan Institute of Metals.

Best Poster Award
○Hiroki Amano, Takuya Ishimoto, Shihai Sun, Takayoshi Nakano:
The effect of ambient gas on the build, in metal laser stacked fabrication,
Best Poster Award at the 2nd Annual Meeting of the Metallurgical Society of Japan, Kobe International Conference Center, December 8, 2019.

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Poster Award
○Yukinobu Ito, Takuya Ishimoto, Yusuke Tsutsumi, Takao Hanawa, Shihai Sun, Takayoshi Nakano:
Stainless steel material control, by laser three-dimensional modeling,
Poster Award at the 2nd Annual Meeting of the Metallurgical Society of Japan, Kobe International Conference Center, December 8, 2019.

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○Ryoya Suganuma, Takuya Ishimoto, Takayoshi Nakano:
Mechanism of Microstructure Formation in Additiv Manufacturing of Beta-Ti Alloys by Thermal Diffusion Simulation,
Poster Award at the 2nd Annual Meeting of the Metallurgical Society of Japan, Kobe International Conference Center, December 8, 2019.

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○Kana Nakano, Takeshi Nagase, Mitsuharu Todai, Takayoshi Nakano:
Guidelines for Alloy Design and Microstructure Control of Biological High Entropy Alloys,
Poster Award at the 2nd Annual Meeting of the Metallurgical Society of Japan, Kobe International Conference Center, December 8, 2019

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The Nikkei Sangyo Shimbun published an article on our discovery of osteocyte projections controlled by proteins.

"Regulated by bone cell projection proteins",
Nikkei Sangyo Shimbun morning edition, page 5 (Advanced Technology), December 5, 2019.

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Dr. Nakano gave a keynote speech at the GE Additive/Arcam-HTL Seminar.

Takayoshi Nakano:
Structure and Material Parameters Control and Functionality, Using Metal AM
December 4, 2019 in Tachikawa

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Nakano Lab's article was published in the December issue of "Kagaku Kogyo".

Aira Matsugaki and Takayoshi Nakano:
Self-assembly Phenomena in Biological Bone and Its Application to Alternative Materials,
Kagaku Kogyo (Chemical Industry), Vol.70 [12], (2019), pp.44-49.

Click here for PDF

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Technology Roadmap 2020-2029: All Industries Edition (Nikkei Business Publications, Inc.)," which Dr. Nakano contributed to, has been published.

Takayoshi Nakano (shared author):
"9-7. 3D Additive Manufacturing (3D-AM)",
Technology Roadmap 2020-2029: All Industries, Nikkei BP, November 29, 2019, pp. 378-381, ISBN: 978-4-296-10436-9.
Click here for PDF

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Mr. Hieda in Koizumi Lab. won the FGMs Encouragement Award for his presentation at the 2019 Symposium on Gradient Functional Materials. This is a collaborate research with Nakano Lab.

Kengo Hieda, Hirotoshi Kawabata, Yuichiro Koizumi, Takayoshi Nakano:
Melting and solidification behavior at the boundary between Ti-6Al-4V alloy powder and Cu powder by electron beam irradiation for additive manufacturing,
Functionally Gradient Materials FORUM of Japan [FGMs Encouragement Award], "2019 Symposium on Gradient Functional Materials", Nov. 27, 2019.

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A paper in Nakano Lab. won the Best Paper Award from Smart Processing Society for Materials, Environment & Energy.

Takuya Ishimoto, Jumpei Yasutomi, Shota Sugimoto, Takayoshi Nakano:
Microstructure formation of β-type Ti-15Mo-5Zr-3Al alloy by laser additive manufacturing,
Journal of Smart Processing Society for Materials, Environment & Energy, 7 [6], (2018), pp. 229-232.

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A paper on our laboratory's discovery of factors that elongate osteocytes has been published in Materials Science & Engineering C.

Aira Matsugaki, Daisuke Yamazaki, Takayoshi Nakano∗:
Selective patterning of netrin-1 as a novel guiding cue for anisotropic dendrogenesis in osteocytes,
Materials Science & Engineering C, 108, (2020), 110391: 1-6.
https://doi.org/10.1016/j.msec.2019.110391

【Abstract】
Although protein patterning approaches have found widespread applications in tuning surface characteristics of biomaterials, selective control of growth in cell body and dendrites utilizing such platforms remains difficult. The functional roles assumed by cell body and dendrites in a physiological milieu have extremely high specificity. In particular, osteocytes embedded inside the mineralized bone matrix are interconnected via dendritic cell processes characterized by an anisotropic arrangement of the lacunar-canalicular system, where the fluid-flow inside the canaliculi system regulates the mechanoresponsive functionalization of bone. Control of cellular networks connected by dendritic cell processes is, therefore, imperative for constructing artificially controlled bone-mimetic structures and as an extension, for gaining insights into the molecular mechanisms underlying dendrogenesis inside the mineralized bone matrix. Here, we report an innovative strategy to induce controlled elongation of cell body or dendritic process structures in selective directions by using the inkjet printing technique. Artificial runways employing netrin-1, inspired by neural architecture, were utilized to trigger controlled elongation in the osteocyte dendritic processes in desired directions. This is the first report, to the best of our knowledge, demonstrating that anisotropic dendrogenesis of osteocytes can be controlled with selective patterning of extracellular proteins, specifically via the axon guidance ligand netrin-1.

Click here for PDF.

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Mr. Suganuma and Mr. Ito won the Best Presentation Award and the Best Presentation Award, respectively, at the Kansai Branch Meeting of The Iron and Steel Institute of Japan and The Japan Institute of Metals and Materials.

Ryoya Suganuma, Takuya Ishimoto, Yoichi Takagishi, Tatsuya Yamagami, and Takayoshi Nakano:
Elucidation of the Formation Mechanism of β-Ti Alloy Aggregate Structure by SLM with Thermal Diffusion Simulation.

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Yukinobu Ito, Takuya Ishimoto, Yusuke Tsutsumi, Takao Hanawa, Shi-hai Sun and Takayoshi Nakano:
Microstructure Control and Material Property Improvement of Stainless Steel by Laser Additive Manufacturing Method.

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Nakano Lab's article was published in "Zairyo" magazine.

Noriyuki Hisamori, Takuya Ishimoto, Takayoshi Nakano:
Frontiers of Additive Manufacturing in Biomedical Materials,
Materials, 68, [10], 798-803 (2019).

Click here for PDF

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Nakano Lab's article of 3D printer for medical was featured in The Japan Iron and Steel Institute.

Takayoshi Nakano, Takuya Ishimoto:
Application of metal 3D printer technology to medical devices: shape, microstructure, and atomic arrangement control,
Fuerum, 24 [11], (2019), 21(687)-30(696).

Click here for PDF

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Two commentary articles related to Nakano Lab were published in the October issue of Titanium Magazine.

Seong-Ho Lee.
Fabrication of Osteogenesis-Promoting Novel Biomaterials by Titanium/Bioactive Glass Composites Using Additive Manufacturing Method,
Titanium, 64 [4], October, (2019), pp.36(276).

Click here for PDF.

Ken Zhao, Hiroyuki Yasuda, Mitsuharu Todai, Minoru Ueda, Masao Takeyama, and Takayoshi Nakano:.
Peculiar microstructure and mechanical properties of TiAl alloy components in electron beam three-dimensional additive manufacturing process,
Titanium, 64 [4], October, (2019), pp. 50(290)-56(296).

Click here for PDF.

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Mrs. Iijima won the 2nd prize (Silver) in the poster award at Harmonic 2019 4th International Symposium on Hetero Structure and Advanced Materials held at Ritsumeikan University.

○Yuuka Iijima Takeshi Nagase , Aira Matsugaki, Kei Ameyama, Takayoshi Nakano:
The development of novel Ti-Zr-Hf-Co-Cr-Mo bio-high entropy alloy,
A silver poster award of the 4th International Symposium on Hetero Structure and Advanced Materials, October 26th, 2019, Rohm Memorial Hall, Biwako-Kusatsu Campus, Ritsumeikan University, Kusatsu, Shiga, JAPAN.

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Commemorative photo of the award

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Commemorative photo with Dr. Nakano

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Dr. Nakano's commentary will be featured in the November issue of Mechanical Engineering.

Takayoshi Nakano
Formation of specific microstructure and expression of function by metal 3D printer,
Mechanical Engineering November, Vol.67, No.12, Nikkan Kogyo Shimbun, (2019), pp.21-27.

Click here for PDF

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The article, "Professor Takayoshi Nakano wins the Japanese Society for Bone and Metabolism Research Academic Award," has been published.

Click here for this article.

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The commentary was published in "Biomaterials".

Aira Matsugaki and Takayoshi Nakano:
Control of Cell and Bone Orientation by Surface Morphology Specific Orthogonal Bone Orientation Phenomena by Nano-Oriented Grooves,
Biomaterials - Biomaterials, vol. 37, no. 4, pp. 270-271.

Click here for PDF

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Our papers on Ti-Zr-Hf-Cr-Mo alloy and Ti-Zr-Hf-Co-Cr-Mo alloy, which are newly designed as biomaterials, have been published as open access papers in Materials Science and Engineering C.

Takeshi Nagase, Yuuka Iijima, Aira Matsugaki, Kei Ameyama, Takayoshi Nakano*:
Design and fabrication of Ti–Zr-Hf-Cr-Mo and Ti–Zr-Hf-Co-Cr-Mo high-entropy alloys as metallic biomaterials,
Materials Science and Engineering C, (2019), 110322, on line.
https://doi.org/10.1016/j.msec.2019.110322

Abstract
Novel TiZrHfCr0.2Mo and TiZrHfCo0.07Cr0.07Mo high-entropy alloys for metallic biomaterials (bio-HEAs) were developed based on the combination of Ti-Nb-Ta-Zr-Mo alloy system and Co-Cr-Mo alloy system as commercially-
used metallic biomaterials. Ti-Zr-Hf-Cr-Mo and Ti-Zr-Hf-Co-Cr-Mo bio-HEAs were designed using (a) a tree-like diagram for alloy development, (b) empirical alloy parameters for solid-solution-phase formation, and © thermodynamic calculations focused on solidification. The newly-developed bio-HEAs overcomes the limitation of classical metallic biomaterials by the improvement of (i) mechanical hardness and (ii) biocompatibility all together. The TiZrHfCr0.2Mo and TiZrHfCo0.07Cr0.07Mo bio-HEAs showed superior biocompatibility comparable to that of commercial-purity Ti. The superior biocompatibility, high mechanical hardness and low liquidus temperature for the material processing in TiZrHfCr0.2Mo and TiZrHfCo0.07Cr0.07Mo bio-HEAs compared with the Ti-Nb-Ta-Zr-Mo bio-HEAs gave the authenticity of the application of bio-HEAs for orthopedic implants with multiple functions.

Click here for this paper.
Click here for PDF

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We received The Japan Institute of Metals and Materials The Metals Best Poster Awards.

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〇Haruka Kondo, Ryosuke Ozasa, Takayoshi Nakano, Kozo Makino:
Changes in bone apatite orientation in acquired hypertensive rats,
The Japan Institute of Metals and Materials The Metals Best Poster Awards, "High School and College of Technology Student Poster Presentation" , Okayama University, September 11, 2019.

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〇Ryo Takehana, Aira Matsukaki, Kosuke Kawahara, Takafumi Ninomiya, Hiroshi Sawada, and Takayoshi Nakano:
Microperiodic structure-dependent orientation behavior of osteoblasts and bone matrix,
The 33rd Annual Meeting of the Japan Institute of Metals and Materials, The Japan Institute of Metals and Materials The Metals Best Poster Awards, Okayama University, September 11, 2019.

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〇Tsubasa Todo, Takuya Ishimoto, Shihai Sun, Yoshio Ueda, Takayoshi Nakano:
Fabrication and microstructure formation of tungsten dense body by laser lithography,
The 33rd Annual Meeting of the Japan Institute of Metals and Materials, The Japan Institute of Metals and Materials The Metals Best Poster Awards, Okayama University, September 11, 2019.

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〇Fumihito Nakamura, Ryosuke Ozasa, Takayoshi Nakano:
Changes in bone orientation and osteomechanical function during the perinatal period,
The 33rd Annual Meeting of the Japan Institute of Metals and Materials, The Japan Institute of Metals and Materials The Metals Best Poster Awards, Okayama University, September 11, 2019.

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〇Ryo Fukushima, Takuya Ishimoto, Hiroshi Oji, Takayoshi Nakano:
Orientation of collagen and apatite crystals under zinc-deficient diet,
The 33rd Annual Meeting of the Japan Institute of Metals and Materials, The Japan Institute of Metals and Materials The Metals Best Poster Awards, Okayama University, September 11, 2019.

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〇Tadaaki Matsuzaka, Aira Matsukaki, Takayoshi Nakano:
Elucidation of the orientation behavior of cells and bone matrix by constructing an anisotropic co-culture model under stress loading,
The 33rd Annual Meeting of the Japan Institute of Metals and Materials, The Japan Institute of Metals and Materials The Metals Best Poster Awards, Okayama University, September 11, 2019.

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A collaborate research results with the Department of Orthopaedic Surgery, Osaka University were published in Bone.

Kazuma Kitaguchi, Masafumi Kashii, Kosuke Ebina, Takashi Kaito, Rintaro Okada, Takahiro Makino, Etani Yuki, Takuya Ishimoto, Takayoshi Nakano, Hideki Yoshikawa:
The combined effects of Teriparatide and Anti-RANKL Monoclonal Antibody on Bone Defect Regeneration in Ovariectomized Mice,
Bone, (2019), on line.

Abstract
Objective
The purpose of this study was to investigate the combined effects of teriparatide (TPTD) and anti-murine receptor activator of nuclear factor-κB ligand monoclonal antibody (anti-RANKL Ab) on both cancellous and cortical bone healing in ovariectomized mice.

Methods
Thirteen-week-old mice were divided into the sham-operated group (n = 11) or the ovariectomized group (n = 44). At 1 month post-operation, all mice underwent bone defect surgery on the left femoral metaphysis (cancellous bone healing model) and right femoral mid-diaphysis (cortical bone healing model). After creating the bone defects, all ovariectomized mice were assigned to one of four groups to receive 1) saline (5 times a week; CNT group), 2) TPTD (40 μg/kg 5 times a week; TPTD group), 3) anti-RANKL Ab (5 mg/kg once; Ab group), or 4) a combination of TPTD and anti-RANKL Ab (COMB group). The following analyses were performed: Time-course microstructural analysis of healing in both cancellous and cortical bone in the bone defect, measuring the volumetric bone mineral density and the cortical bone thickness of the tibia as a representative of whole body bone with the use of micro-computed tomography, and histological analysis.

Results
Regeneration of cancellous bone volume in the COMB group was the highest among the four groups, and combined treatment accelerated the formation of medullary callus during the early phase of bone regeneration. On the other hand, there were no significant differences in the regeneration of cortical bone volume during the early phase of bone regeneration among the four groups. Furthermore, lamellar bone was not well identified in the all four groups. Volumetric bone mineral density in the tibia in the COMB group was significantly higher compared with that in the CNT and TPTD groups and tended to be higher compared with that in the Ab group. The mean values of cortical bone thickness in the TPTD and COMB groups were significantly higher than that in the CNT group.

Conclusion
In a mouse model of postmenopausal osteoporosis, combination therapy of TPTD and anti-RANKL Ab accelerates regeneration of cancellous bone more effectively than either agent alone during the early phase of bone regeneration.

Click here for this paper

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At the 37th Annual Meeting of the Japanese Society of Bone Metabolism (held jointly with the 21st Annual Meeting of Japan Osteoporosis Society) (Kobe International Conference Center), Dr. Nakano became the second person in the School of Engineering to rec

Takayoshi Nakano:.
2019 Academic Award of the Japanese Society of Bone Metabolism Research (Basic), for his longtime contribution to "Research on the orientation of bone matrix (collagen fibrils/apatite crystals) as a bone quality indicator",
at Kobe International Conference Hall, October 13, 2019.

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Commemorative plaque and certificate

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Dr. Nakano's award lecture

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In the morning edition of the Nihon Keizai Shimbun, it was reported that a collaborate research with Dr. Ueki (Kinki Univ.) and Prof. Narushima (Tohoku Univ.) has succeeded in significantly improving the performance of coronary stents by using a new two-s

Kosuke Ueki, Takayoshi Nakano, Naoyuki Narushima:
New material for stents that combines strength and elongation,
September 30, 2019, Nihon Keizai Shimbun, Morning Edition, page 13 (Science & Technology).

Click here for the electronic version of the article.

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Two explanatory articles from Nakano Research Institute will appear in the November issue of Forum (The Iron and Steel Institute of Japan) and in the November issue of Kikai Gijutsu (Nikkan Kogyo Shuppan).

〇Takayoshi Nakano, Takuya Ishimoto:
Application of Metal 3D Printer Technology to Medical Devices: Shape, Microstructure, and Atomic Arrangement Control,
Serial article, Special issue on "3D printer opens the way to the next generation manufacturing", Forum, November issue (2019)

〇Takayoshi Nakano:
Formation of specific tissues and expression of functions by metal 3D printer,
Special Issue on "Metal 3D printer opens up the way to manufacturing - Advanced technology for additive manufacturing", Mechanical Technology, November (2019).

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The commentary was published in the feature article "Metallic Biomaterials" in the September issue of Special Steel.

Takayoshi Nakano:
Titanium and titanium alloys,
Special Steel, Vol. 68, No. 5 [September], (2019), pp. 23-26.

Click here for this PDF.

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The commentary was published in the special feature "Recent Trends in Metalloid Additive Manufacturing Technology" in the Journal of Japan Foundry Engineering Society "Foundry Engineering".

Takeshi Nagase, Mitsuyo Toshiro, and Takayoshi Nakano:
Additive manufacturing of titanium alloy using pure elemental powders,
Journal of Japan Foundry Engineering Society, Special Issue on Recent Trends in Metal Laminated Molding Technology, 91 [9], (2019), pp. 627-633.

Click here for this PDF.

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As a collaborative research between Kindai University, Tohoku University, and Osaka University, a paper on a heat treatment process that combines high strength and high ductility with expandability applicable to stents has been published in Materials Scie

Kosuke Ueki*, Soh Yanagihara, Kyosuke Ueda, Masaaki Nakai, Takayoshi Nakano, Takayuki Narushima:
Overcoming the strength-ductility trade-off by the combination of static recrystallization and low-temperature heat-treatment in Co-Cr-W-Ni alloy for stent application,
Materials Science and Engineering A, 766, (2019) paper# 138400: 1-11

Click here for this paper.
Click here for this PDF.

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Members of Nakano Lab. participated in the 2019 Autumn Meeting of The Japan Institute of Metals and Materials(165th) held at Okayama University on 9/11-9/13.

Dr. Nakano served as the Vice President of the Japan Institute of Metals and the Chairperson of the Conference Committee, and chaired the K3 Session on Recent Trends in Materials Technology Contributing to the Automotive Revolution, Dr. Ishimoto chaired the S7 Session on Materials Science and Technology for Additive Manufacturing in Medicine and Welfare, and Dr. Ozasa chaired the Biomaterials Design Development and Clinical Practice (1) Session.
The presentations are as follows.

The Japan Institute of Metals and Materials Murakami Young Researcher Award Lecture

○Takuya Ishimoto
Research on functionalization of biological bones and biomaterials based on metallic materials engineering

Oral Presentation

○Takuya Ishimoto, Junpei Yasutomi, Shihai Sun, Takayoshi Nakano:
Formation of Specific Assembly Structure and Mechanical Properties of Inconel 718 by Laser Additive Manufacturing Method

○Takuya Ishimoto, Junpei Yasutomi, Shihai Sun, Takayoshi Nakano:
Microstructural changes in bone due to malignant bone tumor formation

○Ryosuke Ozasa, Takayoshi Nakano:
Effect of blood pressure change on bone microstructure

○Shihai Sun, Koji Hagiwara, Takuya Ishimoto, Takayoshi Nakano:
Comparison of crystallographic texture and mechanical property of Ti-15Mo-5Zr-3Al alloy fabricated by electron and laser beam melting

○Yuka Iijima, Taketsugu Nagase, Aira Matsugaki, Takuya Ishimoto, Megumi Ameyama, Takayoshi Nakano:
Microstructure and properties of Ti-Zr-Hf-Co-Cr-Mo biological high-entropy alloys

○Natsuki Okuda, Takuya Ishimoto, Takayoshi Nakano:
A proposal for anisotropic bone reconstruction using bone cross-sectional anisotropy

○Yoshiya Kobayashi, Takuya Ishimoto, Manabu Ito, Takayoshi Nakano:
Effect of autogenous bone grafting on bone integrity formed in spinal cages

○Kyohei Sasaki, Ryosuke Ozasa, Takayoshi Nakano:
Elucidation of the mechanism of bone orientation by ApoE gene

○Tatsuki Harada, Aira Matsugaki, Takayoshi Nakano:
Regulatory mechanism of bone orientation based on dynamic interaction with cancer cells

○Atsushi Moriguchi, Ryosuke Ozasa, Takeshi Moriishi, Toshihiro Miyazaki, Hisafumi Komori, Takayoshi Nakano:
Elucidation of the mechanism of apatite orientation using a regenerative bone model

○Yukinobu Ito, Takuya Ishimoto, Yusuke Tsutsumi, Takao Hanawa, Shihai Sun, Takayoshi Nakano
Control of aggregate structure and improvement of material properties of stainless steel by metal AM

○Ryoya Suganuma, Takuya Ishimoto, Yoichi Takagishi, Tatsuya Yamagami, Takayoshi Nakano
Clarification of formation mechanism of β-type Ti alloy microstructure by laser lamination method using thermal diffusion simulation

○Yuichiro Koizumi, Takayoshi Nakano:
Computer simulation for metal additive manufacturing

○Masakazu Tane, Norihiko Okamoto, Koji Inoue, Martin Luckabauer, Kosuke Nagai, Toru Sekino, Takayoshi Nakano, Satoshi Ichitsubo:
Non-diffusion isothermal ω-transformation in β-type titanium alloys induced by frozen alloy composition fluctuations

○Hiroki Narimoto, Koji Hagiwara, Takayoshi Nakano, Michiaki Yamazaki, Yoshihito Kawamura:
Control of kink zone formation and distribution in Mg-based LPSO phase

○Ken Zhao, Masahiro Sakata, Hiroyuki Yasuda, Mitsuharu Todai, Minoru Ueda, Masao Takeyama, Takayoshi Nakano:
Ductility improvement of TiAl alloy by controlling specific banded microstructure using electron beam three-dimensional lamination

○Hajime Kawabata, Ken Zhao, Hiroyuki Yasuda, Mitsuharu Todai, Minoru Ueda, Masao Takeyama, Takayoshi Nakano:
Effect of shape on microstructure of TiAl alloys fabricated by electron beam 3D additive manufacturing

○Jun Kubo, Yuichiro Koizumi, Takuya Ishimoto, Takayoshi Nakano:
Microscopic simulation of metal powder additive manufacturing

○Yusuke Tsutsumi, Takuya Ishimoto, Kyosuke Ueda, Tetsushi Kuze, Shimpei Maruyama, Akira Matsugaki, Chen Peng, Maki Roda, Kosuke Ueki, Akihiko Yanagitani, Hideki Katayama, Takayoshi Nakano, Takao Hanawa:
High Corrosion Resistance of Martensitic Stainless Steel by Laser Additive Manufacturing

○Kosuke Ueki, Hajime Yanagihara, Kyosuke Ueda, Masaaki Nakai, Takayoshi Nakano, Naoyuki Narushima:
Improvement of strength and ductility by static recrystallization and low temperature heat treatment process in Co-Cr-W-Ni alloy for biological applications

○Ryohei Ueyama, Koji Hagiwara, Tsuyoshi Mayama, Michiaki Yamazaki, Yoshihito Kawamura, Takayoshi Nakano:
Investigation of kink zone formation behavior in Mg-based LPSO phase by calculation and experiment

○Hirotaka Odo, Ken Zhao, Hiroyuki Yasuda, Mitsuyo Toshiro, Minoru Ueda, Masao Takeyama, Takayoshi Nakano:
Improvement of Room Temperature Fatigue Properties of TiAl Alloy Fabricated by Electron Beam 3D Additive Manufacturing

○Takumi Maeda, Yuichiro Koizumi, Hirotoshi Kawabata, Takuya Ishimoto, Kota Kimura, Shihai Sun, Takayoshi Nakano:
Melt-solidification behavior of Ti-15Mo-5Zr-3Al alloy by laser scanning for powder bed melt-bonded AM

The 33rd Poster Presentation

○Ryo Takehana, Aira Matsukaki, Kosuke Kawahara, Takafumi Ninomiya, Hiroshi Sawada, Takayoshi Nakano:
Microstructure-dependent orientation behavior of osteoblasts and bone matrix

○Tsubasa Todo, Takuya Ishimoto, Shihai Sun, Yoshio Ueda, Takayoshi Nakano:
Fabrication of Dense Body and Assembly Tissue Formation by Laser Additive Manufacturing of Tungsten

○Fumihito Nakamura, Ryosuke Kozasa, Takayoshi Nakano:
Changes in bone orientation and osteomechanical function during the perinatal period

○Ryo Fukushima, Takuya Ishimoto, Hiroshi Oji, Takayoshi Nakano:
Orientation of collagen and apatite crystals under zinc-deficient diet

○Tadaaki Matsuzaka, Aira Matsugaki, Takayoshi Nakano:
Elucidation of the orientation behavior of cells and bone matrix by constructing an anisotropic co-culture model under stress load

○Yusuke Yamaoka, Ryosuke Ozasa, Takayoshi Nakano:
Changes in bone microstructure due to abnormal phosphorus metabolism

2nd Poster Presentation by High School and College of Technology Students

Yuka Kondo, Ryosuke Ozasa, Takayoshi Nakano, Kozo Makino:
Changes in Bone Apatite Orientation in Acquired Hypertensive Rats

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Dr. Ishimoto was awarded "The 16th Japan Institute of Metals and Materials Murakami Young Researcher Award" at the 2019 Fall Meeting of the Japan Institute of Metals (165th).

Takuya Ishimoto:
Research on the functionalization of biological bones and materials based on metallic materials engineering

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The Matelia manuscript written by Nakano Lab. was awarded the Materia Japan Award at the 2019 Fall Meeting of the Japan Institute of Metals (165th), and Dr. Todai received the award on behalf of the group.

Mitsuharu Todai, Takuya Ishimoto, Aira Matsugaki, Takayoshi Nakano:
Construction of design guidelines for the development of next-generation biomaterials

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Ms. Haruka Kondo, who is a high school student, Mr. Takehana (M1), Mr. Todo(M1), Mr. Nakamura(M1), Mr. Fukushima (B4), and Mr. Matsuzaka (B4) won The Japan Institute of Metals and Materials The Metals Best Poster Award.

○Haruka Kondo, Ryosuke Ozasa, Takayoshi Nakano, Kozo Makino:
Changes in bone apatite orientation in acquired hypertensive rats

○Ryo Takehana, Aira Matsugaki, Kosuke Kawahara, Takafumi Ninomiya, Hiroshi Sawada, Takayoshi Nakano:
Microperiodic structure-dependent orientation behavior of osteoblasts and bone matrix

○Tsubasa Todo, Takuya Ishimoto, Shihai Sun, Yoshio Ueda, Takayoshi Nakano:
Fabrication of Dense Body and Assembly Tissue Formation by Laser Additive Manufacturing of Tungsten

○Fumihito Nakamura, Ryosuke Ozasa, Takayoshi Nakano:
Changes in bone orientation and osteomechanical function during the perinatal period

○Ryo Fukushima, Takuya Ishimoto, Hiroshi Oji, Takayoshi Nakano:
Orientation of collagen and apatite crystals under zinc-deficient diet

○Tadaaki Matsuzaka, Aira Matsugaki, Takayoshi Nakano:
Elucidation of the orientation behavior of cells and bone matrix by constructing an anisotropic co-culture model under stress loading

Translated with www.DeepL.com/Translator (free version)

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An article about Nakano Laboratory was posted on the website and SNS of the School of Engineering and Graduate School of Engineering, Osaka University.

Here, you can see our laboratory's research scenes and 3D printed objects through videos and other media.

Click here for the website of the Graduate School of Engineering, Osaka University
Click here for the Facebook page of the Graduate School of Engineering, Osaka University
Click here for the Instagram of Osaka University, School of Engineering and Graduate School of Engineering
Click here for the Twitter page of the Graduate School of Engineering, Osaka University

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Special Issue on Latest Research and Development of Structural and Functional Titanium-Based Materials, organized by Prof. Shinya, Prof. Nakano and others, was published in the September issue of Materials Transactions, and four papers related to Nakano L

Special Issue on Latest Research and Development of Structural and Functional Titanium-Based Materials

PREFACE
Titanium (Ti)-based materials are gaining a lot of attentions in fields including aerospace, medical devices, welfare goods, antibacterial materials, consumer goods, chemical plants, electric generation, ocean thermal energy conversion, and armors. Using an additive manufacturing (AM) to make complex shaped products of Ti-based materials is a topic of research globally. For AM of Ti-based materials, not only processing, but also fundamental research on topics such as solidification, heat flow, crystal graphic analysis, and alloy design are becoming more popular. National projects including Ti-based materials managed by ISMA (Innovative Structural Materials Association), SIP (Cross-materials Strategic Innovation Program) and TRAHAM (Technology Research Association for Future Additive Manufacturing Unions), are also in progress. The 14th World Conference on Titanium, which is the largest international conference on Ti-based materials, was held from June 1014, 2019 at Nantes in France. Therefore, it is now a good time to publish a special issue on the latest topics related to Ti-based materials. Approximately 20 fruitful original technical papers related to all the fields of Ti-based materials including air craft structures and biomedical implants, their surface modifications to enhance the biocompatibility, AM processing, low cost manufacturing, deformation behaviors, and mechanical properties, and effects of low cost elements on their properties are included in this special issue. We are grateful to all the authors for their contributions. We hope this special issue helps to solve important questions related to Ti-based materials.

July 23, 2019
Guest Editors: Takayoshi Nakano1, Takayuki Narushima2, Takao Hanawa3, Masato Ueda4, Yoko Yamabe-Mitarai5, Tadashi Furuhara6, Hideki Hosoda7, Mitsuo Niinomi8
1 Professor, Graduate School of Osaka University,
2 Professor, Graduate School of Tohoku University,
3 Professor, Institute for Biomaterial Engineering, Tokyo Medical and Dental University,
4 Professor, Kansai University, Faculty of Chemistry,
5 Deputy Director, Research Center for Structural Materials, National Institute for Materials Science (NIMS),
6 Professor, Institute for Materials Research, Tohoku University,
7 Professor, Institute of Innovative Research, Tokyo Institute of Technology
8 Professor Emeritus, Tohoku University

〇Takayoshi Nakano, Takayuki Narushima, Takao Hanawa, Masato Ueda, Yoko Yamabe-Mitarai, Tadashi Furuhara, Hideki Hosoda, Mitsuo Niinomi:
PREFACE-Special Issue on Latest Research and Development of Structural and Functional Titanium-Based Materials, Materials Transactions, 60 [9], (2019), 1732.

1) M. Niinomi, T. Akahori, M. Nakai, Y. Koizumi, A. Chiba, T. Nakano, T.Kakeshita, Y. Yamabe-Mitarai, S. Kuroda, N. Motohashi, Y. Itsumi and T.Choda:
Quantitative and Qualitative Relationship between Microstructural Factors and Fatigue Lives under Load- and Strain-Controlled Conditions of Ti5Al2Sn2Zr4Cr4Mo (Ti-17) Fabricated Using a 1500-ton Forging Simulator,
Materials Transactions, 60 [9], (2019), 1740-1748.
Click here for this paper.

2) Qiang Li, Qiang Qi, Junjie Li, Masaaki Nakai, Mitsuo Niinomi, Yuichiro Koizumi, Daixiu Wei, Kenta Yamanaka, Takayoshi Nakano, Akihiko Chiba, Xuyan Liu and Deng Pan:
Low Springback and Low Young’s Modulus in Ti29Nb13Ta4.6Zr Alloy Modified by Mo Addition, Materials Transactions, 60 [9], (2019), 1755-1762.
Click here for this paper.

3) Qiang Li, Xufeng Yuan, Junjie Li, Pan Wang, Masaaki Nakai, Mitsuo Niinomi, Takayoshi Nakano, Akihiko Chiba, Xuyan Liu and Deng Pan:
Effects of Fe on Microstructures and Mechanical Properties of Ti15Nb25Zr(0, 2, 4, 8)Fe Alloys Prepared by Spark Plasma Sintering, Materials Transactions, 60 [9], (2019), 1763-1768.
Click here for this paper.

4) Sungho Lee, Jong Yeong Oh, Soichiro Mukaeyama, Shi-Hai Sun, TakayoshiNakano*
: Preparation of Titanium Alloy/Bioactive Glass Composite for Biomedical Applications via Selective Laser Melting, Materials Transactions,
60 [9], (2019), 1779-1784.
Click here for this paper.
Click here for this PDF.

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Our paper on microstructure and mechanical properties of Ti-xNb-2Fe Alloys has been published in "Journal of Materials Engineering and Performance".

Qiang Li, Pu Miao, Junjie Li, Meifeng He, Masaaki Nakai, Mitsuo Niinomi, Akihiko Chiba, Takayoshi Nakano, Xuyan Liu, Kai Zhou, and Deng Pan:
Effect of Nb Content on Microstructures and Mechanical Properties of Ti-xNb-2Fe Alloys,
Journal of Materials Engineering and Performance, (2019),
doi.org/10.1007/s11665-019-04250-5

Abstract
β-Type Ti-Nb-based alloys exhibit satisfactory biocompatibility and low Young's modulus for biomedical applications. The microstructure and mechanical properties of a series of Ti-(14, 16, 18, 20, 22, 24)Nb-2Fe alloys fabricated by arc melting were investigated by XRD, optical microscopy, and tensile tests. Both ω and α″ phases existed in the Ti-14Nb-2Fe alloy, while just a single β phase existed in the other alloys. Twinning is an important deformation mechanism that causes work hardening and twinning-induced plasticity. It was found in the Ti-(14, 16, 18, 20)Nb-2Fe alloys and not in the Ti-22Nb-2Fe alloy. The Ti-14Nb-2Fe alloy exhibited the highest tensile strength and the highest Young's modulus owing to the existence of the ω phase. The tensile strength decreased gradually from 830 MPa (highest) for the Ti-14Nb-2Fe alloy to 540 MPa (lowest) for the Ti-24Nb-2Fe alloy with an increase in the Nb content. The Young's modulus decreased from 90 GPa for the Ti-14Nb-2Fe alloy to 63 GPa for the Ti-22Nb-2Fe alloy and then increased to 71 GPa for the Ti-24Nb-2Fe alloy. Elongation shows the same trend as the Young's modulus. The Ti-22Nb-2Fe alloy, with a low Young's modulus of 63 GPa, tensile strength of 570 MPa, and 15% elongation, was found suitable for biomedical applications. The Ti-20Nb-2Fe alloy also exhibits a high tensile strength, a Young's modulus ratio of 9.24910−3, and 18% elongation and is thus considered another valuable Ti alloy for biomedical applications.

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An article titled "New high-strength alloy for artificial bones" appeared in the morning edition of the Nihon Keizai Shimbun today about the high-strength and high-workability high-entropy alloy developed by the Nakano Laboratory.

New high-strength alloy for artificial bones and other applications
Nihon Keizai Shimbun (page 9: Science and Technology), August 5, 2019

Click here for this ariticle.

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A paper proving that anisotropic rapid yield stress increase can be achieved by adding Al to Mg-Li alloy was published in "Scripta Materia" as an open-access journal.

Koji Hagihara*, Keitaro Moria, Takayoshi Nakano:
Enhancement of plastic anisotropy and drastic increase in yield stress of Mg-Li single crystals by Al-addition followed by quenching,
Scripta Materialia, 172, (2019), 93-97.

Abstract
Strong orientation dependence of yield stress was found in a body-centered cubic (bcc)-structured Mg-Li alloy single crystal by adding 5 at.% of Al combined with rapid quenching, which was negligible in Mg-Li binary single crystals. Furthermore, the addition of 5 at.% of Al combined with rapid quenching caused an extreme increase in yield stress up to ~470 MPa; this compares to ~50 MPa in a Mg-Li binary crystal. Increased valence-electron to atom ratio and development of chemical modulation in the alloy by Al-addition are probable causes of the enhancement of plastic anisotropy and the drastic increase in yield stress, respectively.

Click here for this paper.
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The research on Ti-Nb-Ta-Zr-Mo high-entropy alloys for biological applications with excellent properties of non-equal composition developed in our laboratory has been published as an open access article in the journal "Scripta Materialia".

Takao Hori, Takeshi Nagase, Mitsuharu Todai, Aira Matsugaki, Takayoshi Nakano*:
Development of non-equiatomic Ti-Nb-Ta-Zr-Mo high-entropy alloys for metallic biomaterials,
Scripta Materialia, 172, (2019), 83-87.

Abstract
Nobel non-equiatomic Ti-Nb-Ta-Zr-Mo high-entropy alloys (HEAs) for metallic biomaterials (bio-HEAs) were designed and developed. The pseudo-binary phase diagrams focusing on solidification were constructed by thermodynamic calculations. The shifting the alloy composition of the equiatomic TiNbTaZrMo bio-HEA can realize the drastic improvement of the deformability. Notably, the non-equiatomic Ti, Zr-rich composition stimulatedthe molecular interaction between biological cells and bio-HEA, indicating the possibility of the proposed non-equiatomic Ti-Nb-Ta-Zr-Mo HEAs as an advanced biomaterial for bone tissue engineering applications. This is the first achievement for the alloy design including the control of alloy composition for the development of new bio-HEAs.

Click here for this paper.
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Nakano Lab's commentary and paper were published in the July issue of "The Journal of Smart Processing Society for Materials, Environment & Energy".

Hiroshi Nishikawa and Takayoshi Nakano:
[Preface] Development of Innovative Hard Materials Opened by Additive Manufacturing Process,
The Journal of Smart Processing Society for Materials, Environment & Energy, 8 [4], "Development of Innovative Hard Materials Opened up by Additive Manufacturing Process (2)", (2019), pp.113

Takuya Ishimoto:
Microstructure Control of Beta Titanium Alloy by Additive Manufacturing Process for Reducing Stress Shielding to Bone,
The Journal of Smart Processing Society for Materials, Environment & Energy, 8 [4], "Development of Innovative Hard Materials Opened by Additive Manufacturing Process (2)", (2019), pp.119-123.

Oh Jong Yeong, Takuya Ishimoto, Shi-Hai Sun, Takayoshi Nakano:
Crystallographic texture formation of pure tantalum by selective laser melting method,
The Journal of Smart Processing Society for Materials, Environment & Energy, 8 [4], "Development of Innovative Hard Materials Opened by Additive Manufacturing Process (2)", (2019), pp.151-154.

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A paper on irradiation damage resistance of crosslinked PTFE has been published in Polymer Bulletin.

Hiroshi Saito, Masakazu Furuta, Aira Matsugaki, Takayoshi Nakano, Masako Oishi, Masayuki Okazaki:
Radiation-resistant properties of cross-linking PTFE for medical use,
Polymer Bulletin, (2019), pp.1-12
DOI: https://doi.org/10.1007/s00289-019-02698-y

Abstract
The property changes of two types of partially cross-linking PTFE (XF1B) and totally cross-linking PTFE (XF2) treated by Co-60 γ-rays were examined physically and chemically. The PTFEs were subjected to a tensile strength test, observation by digital microscope, X-ray diffraction, and Raman analysis. XF1B clearly showed a decrease in the tensile breaking strength at 1 kGy, while XF2 showed a decrease in
the tensile breaking strength at a higher irradiation dose, 50 kGy. X-ray diffraction revealed an increase in the (004) peak intensity of XF1B after irradiation. On the other hand, the increase was not proportional to the irradiation dosages. An increase in the peak intensity was not observed in XF2. These results suggest that crystallization by irradiation advanced in XF1B, and the structural change was not significant in XF2. Raman analysis showed an increase in the spectral intensity of XF1B with increasing irradiation dosages, and no significant change in the spectral intensity of XF2. It was suggested that XF1B had been broken down into constituent subunits. The cross-linking PTFEs used in this study did not show marked differences in mechanical or chemical properties when compared with those of non-cross-linking PTFE previously reported. Particularly, it is considered that the mechanical deterioration of XF2 by irradiation was inhibited. Therefore, totally cross-linking PTFE is expected to be a useful medical material for sterilization by irradiation.

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A paper on anisotropic functionalization by metal additive manufacturing was published in the Journal of The Japan Society for Abrasive Technology.

A paper on anisotropic functionalization by metal additive manufacturing was published in the Journal of The Japan Society for Abrasive Technology.

Takuya Ishimoto and Takayoshi Nakano:
Anisotropic Functionalization by Shape and Microstructure Control in Metal AM,
Journal of the Japan Society for Abrasive Grain Processing, (2019), pp.349-352

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An article about the identification of the sequence factor of bone matrix in Nakano Laboratory was published in Nikkan Kogyo Shimbun.

Identifying sequence factors of bone matrix,
The Nikkan Kogyo Shimbun (page 29: Science, Technology and Universities), June 21, 2019.

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An article about our laboratory will be published in the July issue of Modern Chemistry.

Aira Matsugaki, Takayoshi Nakano:
Stress-Induced Bone Remodeling - Surface Morphology that Promotes Bone Orientation and Bone Regeneration,
Gendai Kagaku July, (No.580), Tokyo Kagaku Doujin, (2019), pp.56-59.

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The article about the device for the method of "measuring bone orientation by ultrasound" with Nakano Lab. and Furuno Denki et al. appeared in the morning edition of the Nihon Keizai Shimbun.

Osaka University to use ultrasound to measure bone health,
Nihon Keizai Shimbun, Morning Edition (page 9: Science and Technology), June 17, 2019.

Click here for this article.

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A paper that showed that apatite orientation as a bone quality parameter can be analyzed by a non-invasive method using ultrasound for human bones has been published in Bone as an open-access journal.

Takuya Ishimoto, Ryoichi Suetoshi, Dorian Cretin, Koji Hagihara, Jun Hashimoto, Akio Kobayashi, Takayoshi Nakano*:
Quantitative ultrasound (QUS) axial transmission method reflects anisotropy in micro-arrangement of apatite crystallites in human long bones: A study with 3-MHz-frequency ultrasound,

Bone, 127, (2019), 82-90

https://doi.org/10.1016/j.bone.2019.05.034.

Abstract
Anisotropic arrangement of apatite crystallites, i.e., preferential orientation of the apatite c-axis, is known to be an important bone quality parameter that governs the mechanical properties. However, noninvasive evaluation of apatite orientation has not been achieved to date. The present paper reports the potential of quantitative ultrasound (QUS) for noninvasive evaluation of the degree of apatite orientation in human bone for the first time. A novel QUS instrument for implementation of the axial transmission (AT) method is developed, so as to achieve precise measurement of the speed of sound (SOS) in the cortex (cSOS) of human long bone. The advantages of our QUS instrument are the following: (i) it is equipped with a cortical bone surface-morphology detection system to correct the ultrasound transmission distance, which should be necessary for AT measurement of long bone covered by soft tissue of non-uniform thickness; and (ii) ultrasound with a relatively high frequency of 3 MHz is employed, enabling thickness-independent cSOS measurement even for the thin cortex by preventing guide wave generation. The reliability of the proposed AT measurement system is confirmed through comparison with the well-established direct transmission (DT) method. The cSOS in human long bone is found to exhibit considerable direction-dependent anisotropy; the axial cSOS (3870 ± 66 m/s) is the highest, followed by the tangential (3411 ± 94 m/s) and radial (3320 ± 85 m/s) cSOSs. The degree of apatite orientation exhibits the same order, despite the unchanged bone mineral density. Multiple regression analysis reveals that the cSOS of human long bone strongly reflects the apatite orientation. The cSOS determined by the AT method is positively correlated with that determined by the DT method and sensitively reflects the apatite orientation variation, indicating the validity of the AT instrument developed in this study. Our instrument will be beneficial for noninvasive evaluation of the material integrity of the human long-bone cortex, as determined by apatite c-axis orientation along the axial direction.

Click here for this paper.

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"Biocompatibility of Inorganic/Organic Materials by Surface Treatment and Modification", which Nakano Lab. contributed to, has been published by CMC Publishing.

Ryosuke Kozasa, Takuya Ishimoto, Takayoshi Nakano ( shared authorship):
Microstructure Formation and Orientation Control by Adding Anisotropy to Biomedical Metallic Materials,
Biocompatibility by Surface Treatment and Modification of Inorganic/Organic Materials (supervised by Yuji Haisima), CMC Publishing, (2019).

Click here for more details.

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"Metals for Biomedical Devices - Second Edition (Edited by M. Niinomi)", which Dr. Nakano contributed to, has been published by Elsevier (Woodhead Publishing).

Dr. Nakano was in charge of "Part 2: Mechanical behavior, degradation, and testing of metals for biomedical devices", and wrote about the basics of mechanical functions related to additive manufacturing and the creation of new metallic medical devices considering the anisotropy of bone.

Takayoshi Nakano (Collected written):
Mechanical behavior, degradation, and testing of metals for biomedical devices, Metals for Biomedical Devices –Second Edition (Edited by M. Niinomi),
Elsevier (Woodhead Publishing), (2019) pp.97-126.

Table of Contents
Part 2: Mechanical behavior, degradation, and testing of metals for biomedical devices
3 Physical and mechanical properties of metallic biomaterials 97
3.1 Introduction 97
3.2 Metallic biomaterials which can realize sufficient mechanical
properties for use in vivo 97
3.3 Methods for strengthening metallic biomaterials 110
3.4 Phase rule and phase diagram 111
3.5 Deformation and recovery, recrystallization, and grain
ripening 114
3.6 Microstructure and related mechanical properties in typical metallic
biomaterials 115
3.7 Development of metallic biomaterials based on biological bone
tissues 116
3.8 Additive manufacturing technology for developing metallic
biomaterials 121
3.9 Summary 126
Acknowledgments 126
References 126

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Nakano Lab's commentary and paper were published in the May issue of "The Journal of Smart Process Society for Materials, Environment & Energy".

Hiroyuki Yasuda, Ken Zhao, Mitsuharu Todai, Takayoshi Nakano, Minoru Ueda, Daisuke Kondo, Shotaro Karato, Ayako Ikeda, and Masao Takeyama:
Microstructure Control and Mechanical Properties of TiAl Intermetallic Compound by Additive Manufacturing Process,
The Journal of Smart Process Society for Materials, Environment & Energy, 8 [3], "Development of Innovative Hard Materials Opened by Additive Manufacturing Process (1)", (2019), pp.78-83.

Koji Hagiwara, Takuya Ishimoto, Shihai Sun, and Takayoshi Nakano:
Crystal orientation and microstructure control of silicide intermetallic compounds by additive manufacturing process,.
The Journal of Smart Process Society for Materials, Environment & Energy, 8 [3], "Development of Innovative Hard Materials Opened by Additive Manufacturing Process (1)", (2019), pp.84-89.

Hiroki Amano, Tomoaki Sasaki, Yuji Nomura, Takuya Ishimoto, Takayoshi Nakano:
An Effect of Oxygen in Atmosphere on Spatter Generation in Laser Additive Manufacturing.
The Journal of Smart Process Society for Materials, Environment & Energy, 8 [3], "Development of Innovative Hard Materials Opened by Additive Manufacturing Process (1)", (2019), pp.102-105.

Ryutaro Okada, Yoshimichi Nomura, Kenichiro Igashira, Takayoshi Nakano:
Anisotropic microstructure control for improving creep properties of Ni-based superalloy by additive manufacturing process,.
The Journal of Smart Process Society for Materials, Environment & Energy, 8 [3], "Development of Innovative Hard Materials Opened by Additive Manufacturing Process (1)", (2019), pp.106-111 .

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The research results on the solidification structure of MEA (medium-entropy alloy) and HEA (high-entropy alloy) with TiNbTaZr as the basic composition were published as an open access article in Entropy of MDPI.

Takeshi Nagase, Kiyoshi Mizuuchi, Takayoshi Nakano*:
Solidification microstructures of the ingots obtained by arc-melting and cold crucible levitation melting in an equiatomic TiNbTaZr medium-entropy alloy and TiNbTaZrX (X = V, Mo, W) high-entropy alloys,
Entropy, 21(5), (2019) pp.483: 1-17

Abstract

The solidification microstructures of the TiNbTaZr medium-entropy alloy and TiNbTaZrX (X = V, Mo, and W) high-entropy alloys (HEAs), including the TiNbTaZrMo bio-HEA, were investigated. Equiaxed dendrite structures were observed in the ingots that were prepared by arc melting, regardless of the position of the ingots and the alloy system. In addition, no significant difference in the solidification microstructure was observed in TiZrNbTaMo bio-HEAs between the arc-melted (AM) ingots and cold crucible levitation melted (CCLM) ingots. A cold shut was observed in the AM ingots, but not in the CCLM ingots. The interdendrite regions tended to be enriched in Ti and Zr in the TiNbTaZr MEA and TiNbTaZrX (X = V, Mo, and W) HEAs. The distribution coefficients during solidification, which were estimated by thermodynamic calculations, could explain the distribution of the constituent elements in the dendrite and interdendrite regions. The thermodynamic calculations indicated that an increase in the concentration of the low melting-temperature V (2183 K) leads to a monotonic decrease in the liquidus temperature (TL), and that increases in the concentration of high melting-temperature Mo (2896 K) and W (3695 K) lead to a monotonic increase in TL in TiNbTaZrXx (X = V, Mo, and W) (x  =  0 − 2) HEAs.

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A collaborative study with Dr. Niinomi on the quantitative and qualitative relationship between microstructure factors and fatigue life of Ti alloys under controlled loading and strain conditions has been published early in Materials Transactions.

M. Niinomi, T. Akahori, M. Nakai, Y. Koizumi, A. Chiba, T. Nakano, T. Kakeshita, Y. Yamabe-Mitarai, S. Kuroda, N. Motohashi, Y. Itsumi, T. Choda:
Quantitative and Qualitative Relationship between Microstructural Factors and Fatigue Lives under Load- and Strain-Controlled Conditions of Ti–5Al–2Sn–2Zr–4Cr–4Mo (Ti-17) Fabricated Using a 1500-ton Forging Simulator,
Materials Transactions, (2019),
DOI:10.2320/matertrans.ME201904

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Dr. Ozasa's article on Calcified Tissue International is now available on the 1st Author page of the Japan Society for Bone and Mineral Research website.

Ryosuke Ozasa, Takuya Ishimoto, Sayaka Miyabe, Jun Hashimoto, Makoto Hirao, Hideki Yoshikawa, Takayoshi Nakano*:
Osteoporosis changes collagen/apatite orientation and Young’s modulus in vertebral cortical bone of rat,
Calcified Tissue International, 104 [4], (2019), pp.449-460.
DOI:10.1007/s00223-018-0508-z

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A paper on the successful fabrication of Ti-based alloys with crystal orientation in mixed powders by metal additive manufacturing has been published in Materials & Design as an open access journal.

Takeshi Nagase, Takao Hori, Mitsuharu Todai, Shi-Hai Sun, Takayoshi Nakano*:
Additive manufacturing of dense components in beta-titanium alloys with crystallographic texture from a mixture of pure metallic element powders,
Materials & Design, 173 [107771], (2019) pp.1-10
https://doi.org/10.1016/j.matdes.2019.107771

Abstract

The fabrication of dense components composed of Ti-based alloys, i.e., Ti-X (X=Cr, Nb, Mo, Ta) alloys, from a mixture of pure elemental powders was achieved using selective laser melting (SLM) process. The Ti-Cr alloys comprise β-Ti single-phase components without any non-molten particles and macroscopic defects. The crystallographic texture of these β-Ti-Cr alloys can be controlled effectively by optimizing the build parameters. The development of {001}〈100〉crystallographic orientation during the SLM process is discussed based on the solidification process focusing on the columnar cell growth in the melt pool. These results demonstrate the possibility of fabricating the Ti-based alloy components with well-developed crystallographic texture from the mixture of pure elemental powders using the process of SLM.

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Nakano Lab's collaborative research on titanium alloys has been published in a press release as "Tohoku University and Osaka University demonstrate the existence of a new phase transition called the "non-diffusion isothermal Omega transformation" and clar

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Research on the transformation mechanism of a new Ti alloy, conducted in collaboration with AIST and Tohoku University, was published in Physical Review Materials.

Masakazu Tane, Hiroki Nishiyama, Akihiro Umeda, Norihiko, L. Okamoto, Koji Inoue, Martin Luckabauer, Yasuyoshi Nagai, Tohru Sekino, Takayoshi Nakano, Tetsu Ichitsubo:
Diffusionless isothermal omega transformation in titanium alloys driven by quenched-in compositional fluctuations,
Physical Review Materials 3, 043604, (2019) pp.1-9.

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A paper finding that Tspan11 is one of the regulators of orthogonalized orientation substrates through cell arrangement has been published in Biomaterials (IF=8.8) as an open access journal.

Yohei Nakanishi, Aira Matsugaki, Kosuke Kawahara, Takafumi Ninomiya, Hiroshi Sawada, Takayoshi Nakano*:
Unique arrangement of bone matrix orthogonal to osteoblast alignment controlled by Tspan11-mediated focal adhesion assembly,
Biomaterials, 209, (2019) pp.103-110
DOI: https://doi.org/10.1016/j.biomaterials.2019.04.016

Abstract
During tissue construction, cells coordinate extracellular matrix (ECM) assembly depending on the cellular arrangement. The traditional understanding of the relationship between the ECM and cells is limited to the orientation-matched interaction between them. Indeed, it is commonly accepted that the bone matrix (collagen/apatite) is formed along osteoblast orientation. Nonetheless, our recent findings are contrary to the above theory; osteoblasts on nanogrooves organize formation of the bone matrix perpendicular to cell orientation. However, the precise molecular mechanisms underlying the orthogonal organization of bone matrix are still unknown. Here, we show that mature fibrillar focal adhesions (FAs) facilitate the perpendicular arrangement between cells and bone matrix. The osteoblasts aligned along nanogrooves expressed highly mature fibrillar FAs mediated by integrin clustering. Microarray analysis revealed that Tspan11, a member of the transmembrane tetraspanin protein family, was upregulated in cells on the nanogrooved surface compared with that in cells on isotropic, flat, or rough surfaces. Tspan11 silencing significantly disrupted osteoblast alignment and further construction of aligned bone matrix orthogonal to cell orientation. Our results demonstrate that the unique bone matrix formation orthogonal to cell alignment is facilitated by FA maturation. To the best of our knowledge, this report is the first to show that FA assembly mediated by Tspan11 determines the direction of bone matrix organization.

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An article on the introduction of Additive Manufacturing technology focusing on titanium and titanium alloys appeared in Matelia.

Takayoshi Nakano, Takuya Ishimoto:
Additive Manufacturing Process of Titanium and Titanium Alloys,
Matelia, 58, [4], (2019),pp.181-187.

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Dr. Nakano received The 58th Japan Institute of Metals and Materials Tanikawa-Harris Award at the 2019 (164th) Spring Meeting of the Japan Institute of Metals and Materials.

Takayoshi Nakano:
A Study on Plastic Behavior of Heat-Resistant Intermetallic Compounds Based on Anisotropy and Its Application to Biomaterials,
The 58th Japan Institute of Metals and Materials Tanikawa-Harris Award, The Japan Institute of Metals and Materials 2019 (164th) Spring Meeting, Tokyo Denki University, March 20, 2019.

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The third article in Dr. Nakano's three-part series on metal 3D printers was published today in the Nikkan Kogyo Shimbun.

Design Sekkei, SIP Innovative Design and Manufacturing Technology, "Anisotropic Custom AM to Realize 'Material Revolution",
Nikkan Kogyo Shimbun, March 13, 2019, page 26, Science, Technology and University section.

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The second of Dr. Nakano's three articles on metal 3D printers was published today in the Nikkan Kogyo Shimbun.

SIP Innovative Design and Manufacturing Technology, "Anisotropic Custom AM, Metal 3D Printer: Fixing Problem Areas During Molding",
The Nikkan Kogyo Shimbun, March 6, 2019, page 23, Science and Technology, University section.

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Our paper on low elasticity of Ti-Nb base alloys by Cr addition has been published on line in Journal of Materials Science.

Qiang Li, Guanghao Ma, Junjie Li, Mitsuo Niinomi, Masaaki Nakai, Yuichro Koizumi, Dai-Xiu Wei, Tomoyuki Kakeshita, Takayoshi Nakano, Akihiko Chiba, Xuyan Liu, Kai Zhou, Deng Pan:
Development of low-Young’s modulus Ti–Nb-based alloys with Cr addition,
Journal of Materials Science,54, (2019),pp.8675-8683.
https://doi.org/10.1007/s10853-019-03457-0.

Abstract

Different amounts of Cr were added to a metastable β-type Ti–22Nb (at.%) alloy to obtain desirable mechanical properties, including a low Young’s modulus, high strength, and good plasticity. The mechanical properties and microstructural changes were investigated. Cr has a high ability to stabilize the β phase, as well as suppress both α″ martensite and ω phase transformations during quenching and the stress-induced α″ martensite transformation during tension. Solid solution strengthening is scarcely achieved by Cr addition. The changes in mechanical properties can be attributed to the different β stabilities. The Ti–22Nb–(0,1)Cr alloys have metastable β phases and exhibit double yielding phenomena, indicating a stress-induced α″ martensite transformation. The Ti–22Nb–(2,3)Cr alloys with stable β phases exhibit distinct work hardening caused by a {332}β<113>β twinning, which also occurs in the Ti–22Nb–(0,1)Cr alloys, but not in the Ti–22Nb–4Cr alloy. Low Young’s moduli of approximately 60 GPa are obtained for the Ti–22Nb–(1,2)Cr alloys. The Ti–22Nb–2Cr alloy exhibits desirable properties for biomedical applications, including an ultimate tensile strength of approximately 600 MPa and elongation of approximately 20%.

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Dr. Nakano, Dr. Ishimoto, and Dr. Todai participated in the drafting of the test method for evaluating the interface strength of medical coating films (JSME standard), which was published.

Takayoshi Nakano, Takuya Ishimoto, Mitsuharu Todai (Members of the drafting committee):
Test Method for Evaluation of Interfacial Strength of Medical Coating Films,
Japan Society of Mechanical Engineers (JSME), JSME S 019-2019, (Japan Society of Mechanical Engineers), February 28, 2019, Maruzen, pp. 1-67.

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Dr. Nakano's article on "Construction and regional demonstration of 3D anisotropic customized design/additive manufacturing base", which is a part of the Strategic Innovation Program (SIP) Innovative Design and Manufacturing Technology, was published in t

SIP Innovative Design and Manufacturing Technology, "Anisotropic Custom AM, Metal 3D Printer Utilization, Imitating Nature "in the Necessary Direction",
Nikkan Kogyo Shimbun, February 27, 2019, page 26, Science, Technology and University section.

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The results of a collaborative research paper with the Graduate School of Dentistry at Osaka University have been published as an open access journal in the journal "Scientific Reports" published by Nature.

R. Uemura, J. Miura, T. Ishimoto, K. Yagi, Y. Matsuda, M. Shimizu, T. Nakano & M. Hayashi:
UVA-activated riboflavin promotes collagen crosslinking to prevent root caries,
Scientific Reports, 9, (2019) paper#1252.

Abstract
Root caries is an increasingly problem in aging societies with severe implications for the general health and wellbeing of large numbers of people. Strengthening type-I collagen, a major organic component of human dentin, has proved effective in preventing root caries. This study sought to determine whether exposure to riboflavin followed by UVA irradiation (RF/UVA) could promote additional collagen crosslinking, and thus improve the acid and enzymatic resistance of human dentin under simulated oral environments. If so, it could offer potential for treatment of the intractable problem of root caries. The greatest flexural strengths were found in dentin exposed to a 0.1% riboflavin solution for 1 minute followed by 1,600 mW/cm2 UVA irradiation for 10 minutes. Mineral loss and lesion depth were significantly lower in the RF/UVA group than in the control group. The microstructures of dentinal tubules and collagen networks after RF/UVA treatment retained their original forms after acidic and enzymatic degradation. In conclusion, RF/UVA treatment may be a new method for preventing root caries with promising prospects for clinical application.

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Two commentary articles ("Microstructure Research Frontiers for Materials Development by Microscopy (11)" - Development of Microscopy for Materials Evaluation and Progress of Advanced Evaluation Methods) have been published in Matelia.

Takeshi Nagase, Kiyoshi Mizuuchi, Mitsuharu Todai, Takayoshi Nakano:
Solidification Structure of High-Entropy Alloys Consisting of Group 4, 5, and 6 Elements, which are Being Developed as Heat-Resistant Alloys and Biological Alloys,
Special Issue on Frontiers of Microstructure Research for Materials Development by Microscopy (11) - Development of Microscopy for Materials Evaluation and Advanced Evaluation Methods - Multiscale Observation Using SEM, Matelia, 58 [2] (2019).
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Koji Hagiwara, Takaaki Ikenishi, Takayoshi Nakano:
Lattice lamellar microstructure control of C40/C11b ultra-high temperature heat-resistant multi-phase silicide by co-doping Cr and Ir,
Special Issue on "Microstructure Research Frontline for Materials Development by Microscopy (11)" - Development of Microscopy for Materials Evaluation and Advanced Evaluation Methods - Multiscale Observation Using SEM, Matelia, 58 [2], (2019).
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The collaborative research result with Dr. Takuya Matsumoto of Okayama University Graduate School of Medical and Dental Sciences has been published in "Journal of Biomedical Materials Research Part A" as an open access journal.

Yosuke Kunitomi, Emilio Satoshi Hara, Masahiro, Okada, Noriyuki Nagaoka, Takuo Kuboki, Takayoshi Nakano, Hiroshi Kamioka, Takuya Matsumoto:
Biomimetic mineralization using matrix vesicle nanofragments,
Journal of Biomedical Materials Research Part A, (2019),pp.1021-1030.
https://doi.org/10.1002/jbm.a.36618

Abstract

In vitro synthesis of bone tissue has been paid attention in recent years; however, current methods to fabricate bone tissue are still ineffective due to some remaining gaps in the understanding of real in vivo bone formation process, and application of the knowledge in bone synthesis. Therefore, the objectives of this study were first, to perform a systematic and ultrastructural investigation of the initial mineral formation during intramembranous ossification of mouse calvaria from a material scientists’ viewpoint, and to develop novel mineralization methods based on the in vivo findings. First, the very initial mineral deposition was found to occur at embryonic day E14.0 in mouse calvaria. Analysis of the initial bone formation process showed that it involved the following distinct steps: collagen secretion, matrix vesicle (MV) release, MV mineralization, MV rupture and collagen fiber mineralization. Next, we performed in vitro mineralization experiments using MVs and hydrogel scaffolds. Intact MVs embedded in collagen gel did not mineralize, whereas, interestingly, MV nanofragments obtained by ultrasonication could promote rapid mineralization. These results indicate that mechanically ruptured MV membrane can be a promising material for in vitro bone tissue synthesis.

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Our paper on the development of bioactive glass/poly(lactic acid) composite, a new material to improve bone mass and quality, has been published in the Journal of Biomedical Materials Research Part A as an open access journal.

Sungho Lee, Aira Matsugaki, Toshihiro Kasuga, Takayoshi Nakano*:
Development of bifunctional oriented bioactive glass / poly(lactic acid) composite scaffolds to control osteoblast alignment and proliferation,
Journal of Biomedical Materials Research Part A, (2019),pp.1031-1041.
doi.org/10.1002/jbm.a.36619

Abstract

During the bone regeneration process, the anisotropic microstructure of bone tissue (bone quality) recovers much later than bone mass (bone quantity), resulting in severe mechanical dysfunction in the bone. Hence, restoration of bone microstructure in parallel with bone mass is necessary for ideal bone tissue regeneration; for this, development of advanced bifunctional biomaterials, which control both the quality and quantity in regenerated bone, is required. We developed novel oriented bioactive glass / poly(lactic acid) composite scaffolds by introducing an effective methodology for controlling cell alignment and proliferation, which play important roles for achieving bone anisotropy and bone mass, respectively. Our strategy is to manipulate the cell alignment and proliferation by the morphological control of the scaffolds in combination with controlled ion release from bioactive glasses. We quantitatively controlled the morphology of fibermats containing bioactive glasses by electrospinning, which successfully induced cell alignment along the fibermats. Also, the substitution of CaO in Bioglass®(45S5) with MgO and SrO improved osteoblast proliferation, indicating that dissolved Mg2+ and Sr2+ ions promoted cell adhesion and proliferation. Our results indicate that the fibermats developed in this work are candidates for the scaffolds to bone tissue regeneration that enable recovery of both bone quality and bone quantity.

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The results of our laboratory's discovery that the collagen/apatite orientation changes in the opposite direction depending on osteoporosis factors was published in the Nikkan Kogyo Shimbun.

In postmenopausal osteoporosis caused by estrogen deficiency, the orientation in the direction of principal stress increases, while in nutritional osteoporosis caused by calcium and phosphorus deficiency, it decreases, both of which are abnormal conditions.

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[Press Release] The inauguration of a 3D printer industry-academia-government collaboration base in Kansai, in which Osaka University AM Center will participate as a core member, was announced by the Kinki Bureau of Economy, Trade and Industry and release

A new center will be established mainly in the Kansai region to promote collaboration among companies and universities engaged in research and development for the creation of next-generation 3D printers and to promote their practical use. The Center for Anisotropic Custom Design and AM R&D of Osaka University will play a central role in this project by utilizing the advanced knowledge of anisotropic manufacturing that it has accumulated so far.

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Mr. Iijima (M1) won a poster award at the 2nd Materials Science and Engineering Talk in 2008.

Yuka Iijima, Taketsugu Nagase, Akira Matsugaki, Takuya Ishimoto, Megumi Ameyama (Ritsumeikan Univ.), Takayoshi Nakano:
Alloy design of Ti-Zr-Hf-Co-Cr-Mo biological high-entropy alloys

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The results of our joint research with Hagiwara Lab. won the Best Poster Award at the 2008 Kansai Section Young Researchers' and Graduate Students' Research Presentation Meeting of The Japan Institute of Light Metals.

Yuki Narimoto, Koji Hagiwara, Takayoshi Nakano, Michiaki Yamazaki, and Yoshito Kawamura:
Control of microstructure and mechanical properties through the kink zone in Mg-based LPSO phase,
The Japan Institute of Light Metals, Kansai Section, Osaka University, Jan. 16, 2019.

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The Nikkan Kogyo Shimbun reported the discovery that the layered microstructure of austenitic stainless steel can be controlled by using the metal AM method, resulting in significant improvements in strength and corrosion resistance. This is the result of

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Our laboratory's commentary on bone metabolism and apatite orientation was published in the journal "Renal and Bone Metabolism".

Ryosuke Ozasa, Takuya Ishimoto, Takayoshi Nakano:
Bone metabolism and apatite orientation,
Special Issue on Uremia and Bone," Kidney and Bone Metabolism, 32 [1] (2019) pp. 45-50.

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Dr. Nakano collaborated in writing the book, "Visual Understanding of Biomaterials, Revised 3rd Edition", published by Gakken Medical Shujunsha.

Takayoshi Nakano (Shared authorship).
Visual Understanding of Biomaterials, Revised 3rd Edition (Edited by Tsutomu Furuzono and Masahiro Okada, Clinical Engineering Library Series), in.
Advanced Biomaterials Leading the Age, Gakken Medical Shujunsha, (2018).
Size: B5 size, 164 pages, 3,200 yen (excluding tax), published on October 26, 2018.

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2018

A paper showing that "autogenous bone grafting is not always the cause of good bone union" was published in Materials Transactions as an open access journal.

Hiroyuki Takahashi, Takuya Ishimoto, Takayuki Inoue, Hiroomi Kimura, Keita Uetsuki, Natsuki Okuda, Yohei Nakanishi, Jong Yeong Oh, Manabu Ito, Yoshio Nakashima, Takao Hanawa, Takayoshi Nakano*:
Effects of Autogenous Bone Graft on Mass and Quality of Trabecular Bone in Ti–6Al–4V Spinal Cage Fabricated with Electron Beam Melting,
Materials Transactions, 60 [1], (2019), pp.144-148.
DOI:.org/10.2320/matertrans.M2018329.

Abstract
A spinal cage is one of the primary spinal devices used for the treatment of spinal diseases such as lumbar spondylolisthesis. Since it is set in the intervertebral space that causes instability to promote the fusion of the adjacent vertebral bodies, it requires the early induction of healthy bones. For this reason, in most cases, an autogenous bone extracted from the patient’s ilium is implanted in the interior of the cage to stimulate bone formation. However, collecting autogenous bone involves secondary surgery and several clinical problems such as pain in the part from which it is collected. Additionally, the effect of the autogenous bone graft itself has not been sufficiently studied yet. Moreover, the mechanical functions of trabecular bones in a vertebral body are governed by the anisotropic structure of the trabeculae and the preferential orientation of the apatite/collagen in a trabecula with respect to the principal stress. Despite this fact, after the implantation of the cage, the mass of the bones is evaluated with soft X-ray photography, which does not guarantee an accurate measurement of bone functions. In this study, the effect of the autogenous bone graft on the spinal cage was verified based on structural anisotropy of trabecular bones and the preferential orientation of apatite/collagen in a trabecula using sheep. The autogenous bone graft demonstrated a significant effect on the increase of bone mass and anisotropy of the trabecular structure. However, compared to the trabecular anisotropy of normal parts, the anisotropy of the trabecular structure and apatite c-axis orientation of the parts with autogenous bone graft were considerably lower, indicating a minimal effect of the autogenous bone graft. Therefore, it was suggested that early stabilization of the spinal cage requires another strategy that rapidly forms the unique hierarchical anisotropic structure of trabecular bones.

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A paper demonstrating that osteoporosis significantly alters bone orientation from its optimal value was published in Calcified Tissue International as an open access journal. This is a collaborative research with Department of Orthopaedic Surgery, Osaka

Ryosuke Ozasa, Takuya Ishimoto, Sayaka Miyabe, Jun Hashimoto, Makoto Hirao, Hideki Yoshikawa, Takayoshi Nakano*:
Osteoporosis changes collagen/apatite orientation and Young’s modulus in vertebral cortical bone of rat,
Calcified Tissue International, (2018), pp.449-460.
DOI:10.1007/s00223-018-0508-z

Abstract
This study revealed the distinguished changes of preferential orientation of collagen and apatite and Young’s modulus in two different types of osteoporotic bones compared with the normal bone. Little is known about the bone material properties of osteoporotic bones; therefore, we aimed to assess material properties in osteoporotic bones. 66 female Sprague–Dawley rats were used. We analyzed the volumetric bone mineral density, collagen/apatite orientation, and Young’s modulus of fifth lumbar vertebral cortex for osteoporotic rats caused by ovariectomy (OVX), administration of low calcium and phosphate content (LCaP) diet, and their combination (OVX+LCaP), as well as sham-operated control. Osteocyte conditions were assessed by hematoxylin and eosin and immunohistochemical (matrix extracellular phosphoglycoprotein (MEPE) and dentin matrix protein 1 (DMP1)) staining. All osteoporotic animals showed bone loss compared with the sham-operated control. OVX improved craniocaudal Young’s modulus by enhancing collagen/apatite orientation along the craniocaudal axis, likely in response to the elevated stress due to osteoporotic bone loss. Conversely, LCaP-fed animals showed either significant bone loss or degraded collagen/apatite orientation and Young’s modulus. Osteocytes in LCaP and OVX+LCaP groups showed atypical appearance and MEPE- and DMP1-negative phenotype, whereas those in the OVX group showed similarity with osteocytes in the control group. This suggests that osteocytes are possibly involved in the osteoporotic changes in collagen/ apatite orientation and Young’s modulus. This study is the first to demonstrate that osteoporosis changes collagen/apatite orientation and Young’s modulus in an opposite manner depending on the cause of osteoporosis in spite of common bone loss.

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Three collaborative papers from Nakano Lab have been published in Materials Science Forum.

Mitsuharu Todai, Takeshi Nagase, Takao Hori, Hiroyuki Motoki, Shi-Hai Sun, Koji Hagihara, Takayoshi Nakano:
Fabrication of the Beta-Titanium Alloy Rods from a Mixture of Pure Metallic Element Powders via Selected Laser Melting,
Materials Science Forum, 941, (2018), pp.1260-1263.
doi:10.4028/www.scientific.net/MSF.941.1260

Abstract
The powder-bed additive manufacturing (AM) process offers advantages in terms of reduced material waste, ability to create complex shape and a decrease in the lead time from design to manufacturing. Recently, custom-made implant of Ti alloys is being developed by selective laser melting (SLM) in additive manufacturing (AM) process. However, the difficulty in the fabrication of titanium alloys due to their pre-alloyed powder cost, resulting in a limited usage of titanium alloys. To overcome this disadvantage, it is effective to fabricate the Ti alloys by SLM from mixture of pure elemental powders. In this case, it is avoided the preparing of the pre-alloyed powders. Therefore, the purpose of the present study is the trying to the fabrication of the Ti-20at.%X (X = Cr, Nb) alloys from the mixture of pure elemental powders by SLM.

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Masahiro Sakata, Jong Yeong Oh, Ken Cho, Hiroyuki Y. Yasuda, Mitsuharu Todai, Takayoshi Nakano, Ayako Ikeda, Minoru Ueda, Masao Takeyama:
Effects of Heat Treatment on Unique Layered Microstructure and Tensile Properties of Tial Fabricated by Electron Beam Melting,
Materials Science Forum, 941, (2018), pp. 1366-1371.
doi:10.4028/www.scientific.net/MSF.941.1366

Abstract
In the present study, effects of heat treatment on microstructures and tensile properties of the cylindrical bars of Ti-48Al-2Cr-2Nb (at.%) alloy with unique layered microstructure consisting of equiaxed γ grains region (γ band) and duplex-like region fabricated by electron beam melting (EBM) were investigated. We found that it is possible to control width of the γ bands (Wγ) by heat treatments at 1100°C and 1190°C. The Wγ increases with decreasing heat treatment temperature. The bars heat-treated at 1190°C exhibit high elongation of 2.9% at room temperature (RT) with maintaining high strength. The RT elongation increases with increasing the Wγ because of increasing deformable regions. In contrast, the RT elongation of the bars decreases with increasing the Wγ when Wγ is very large. This is because the large γ band leads intergranular fracture. These results indicate that there is appropriate width for the γ band to obtain excellent tensile properties at RT.

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Ken Cho, Ryota Kobayashi, Takuma Fukuoka, Jong Yeong Oh, Hiroyuki Y. Yasuda, Mitsuharu Todai, Takayoshi Nakano, Ayako Ikeda, Minoru Ueda, Masao Takeyama:
Microstructure and Fatigue Properties of TiAl with Unique Layered Microstructure Fabricated by Electron Beam Melting,
Materials Science Forum, 941, (2018), pp. 1597-1602.
doi:10.4028/www.scientific.net/MSF.941.1597

Abstract
In Ti-48Al-2Cr-2Nb (at.%) alloys fabricated by electron beam melting (EBM), a unique layered microstructure composed of duplex-like region and equiaxed γ grains (γ bands) is formed at an appropriate process condition. The fatigue behavior of the TiAl alloy fabricated by EBM at an angle ( θ ) of 90° between the building direction and loading axis was investigated focusing on the layered microstructure and test temperature. At room temperature (RT), fatigue strength at θ = 90° is higher than that at θ = 0°. In particular, in low-cycle fatigue life region, the fatigue properties at θ = 90° without hot isostatic pressing (HIP) are comparable to those of the cast alloys with HIP. The γ bands act as an effective barrier to the crack propagation, resulting in high fatigue strength at RT. On the other hand, the fatigue strength at θ = 90° is lower than that at θ = 0° in low-cycle fatigue life region at 1023 K, since the γ bands cannot suppress the crack propagation at 1023 K. However, at 1023 K, the fatigue strength at θ = 90° in the low-cycle region is similar to that of the cast alloys with HIP, due to the fine grain size after EBM

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Our research on the development of a new anisotropic low elasticity βTi alloy and its guidelines was published in "JALCOM" as an open access journal.

Pan Wang*, Mitsuharu Todai, Takayoshi Nakano*:
Beta titanium single crystal with bone-like elastic modulus and large crystallographic elastic anisotropy,
Journal of Alloys and Compounds, (2018),pp.1-17
DOI: 10.1016/j.jallcom.2018.12.236.

Abstract

To develop single crystalline beta titanium implant as new hard tissue replacements for suppressing the stress shielding, we design a Ti-26.6Nb-6.7Al alloy (at. %) single crystal that exhibits large crystallographic elastic anisotropy and low Young's modulus. The anisotropy factor, A, reaches 3.42 that is the highest among all the reported values. The Young's modulus along 〈<100〉> direction, E100, is only 36 GPa that is similar to the Young's modulus of cortical bone. These results prove our proposed design strategy and provide a new path to design beta titanium single crystal with bone-like elastic modulus for implant to minimize stress shielding.

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Two commentary articles ("Microstructure Research Frontiers for Materials Development by Microscopy (11)" - Development of Microscopy for Materials Evaluation and Progress of Advanced Evaluation Methods) were published in Matelia.

Ryosuke Ozasa, Takayoshi Nakano:
Visualization of Vascular Network in Bone Marrow by In vivo Imaging, Special Issue on Microstructure Research Frontiers for Materials Development by Microscopy (11) - Development of Microscopy for Materials Evaluation and Advanced Evaluation Methods-,
Materia, 57 [12], (2018), pp. 598.

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Koji Hagiwara, Takayoshi Nakano, Michiaki Yamazaki, Yoshihito Kawamura:
Peculiar deformation zone formation in various anisotropic materials including Mg-based LPSO phase, Special Issue on "Frontiers of Microstructure Research for Materials Development by Microscopy (11)" - Development of Microscopy for Materials Evaluation and Progress of Advanced Evaluation Methods-,
Materia, 57 [12], (2018), pp. 607.

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Ms. Wu (M2) won the Technical Encouragement Award at the Autumn Meeting of Smart Processing Society for Materials, Environment & Energy.

Siki Wu, Takuya Ishimoto, Shihai Sun, and Takayoshi Nakano: fabrication and microstructure of
Fabrication and microstructure of stainless steel components by laser additive manufacturing,
the Autumn Meeting of Smart Processing Society for Materials, Environment & Energy, Nihonbashi Life Science Building, November 27, 2018.

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Our paper on AM of βTi alloy has been published in the journal of Smart Processing Society for Materials, Environment & Energy.

Takuya Ishimoto, Jumpei Yasutomi, Shota Sugimoto, and Takayoshi Nakano:
Assembly microstructure formation in β-type Ti-15Mo-5Zr-3Al alloy by laser additive manufacturing,
Journal of Smart Processing Society for Materials, Environment & Energy, 7 [6],(2018),pp.229-232.

Abstract

Selective laser melting (SLM), a kind of additive manufacturing (AM) technologies, enables to fabricate highly complicated 3-dimensional structures from a powdered metallic materials. Recent investigations demonstrated the ability of SLM to form crystallographically texturized parts. Highly texturized materials exhibit anisotropic functions; therefore, control of texture via AM is becoming attractive strategy for developing functionalized materials. In the present study, we tried to find laser conditions for formation of randomly and highly texturized parts in SLM of T-15Mo-5Zr-3Al biomedical alloy. We successfully achieved randomly and highly texturized parts under the conditions of (low laser power and low scan speed) and (high laser power and high scan speed), respectively. The highly texturized part showed anisotropy in Young’s modulus in which the value in <001> oriented direction was significantly lower than that in <011> oriented direction, the similar trend to those reported in single crystal of this alloy. The evolution of crystallographic texture was thought to be related with melt-pool shape, which needs further investigations.

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Dr. Ishimoto received the Scientific Encouragement Award at the 40th Annual Meeting of the Japanese Society for Biomaterials, and gave the award lecture.

Takuya Ishimoto:
Quantitative analysis of bone collagen/apatite crystal orientation and elucidation of bone regeneration mechanism,
Scientific Encouragement Award of the Japanese Society for Biomaterials, The 40th Annual Meeting of the Japanese Society for Biomaterials (Kobe International Conference Center), November 12, 2018.

~Comments from Dr. Ishimoto
I am very happy to receive such a prestigious award. I would like to express my sincere gratitude to Dr. Nakano, the students of Nakano Lab, and the many professors with whom I have collaborated for their guidance and cooperation. Thank you very much. I will continue to work hard on biomaterials and bone research for biomaterials, and I look forward to your guidance.

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A paper on the mechanism of bone metastasis of cancer has been published in Int. J. Mol. Sci (MDPI).

A. Matsugaki, T. Harada, Y. Kimura, A. Sekita, T. Nakano:
Dynamic Collision Behavior Between Osteoblasts and Tumor Cells Regulates the Disordered Arrangement of Collagen Fiber/Apatite Crystals in Metastasized Bone,
Int. J. Mol. Sci., 19(11), (2018), 3474.pages.1-11
https://doi.org/10.3390/ijms19113474

Abstract

Bone metastasis is one of the most intractable bone diseases; it is accompanied with a severe mechanical dysfunction of bone tissue. We recently discovered that the disorganized collagen/apatite microstructure in cancer-bearing bone is a dominant determinant of the disruption of bone mechanical function; disordered osteoblast arrangement was found to be one of the principal determinants of the deteriorated collagen/apatite microstructure. However, the precise molecular mechanisms regulating the disordered osteoblast arrangement triggered by cancer invasion are not yet understood. Herein, we demonstrate a significant disorganization of bone tissue anisotropy in metastasized bone in our novel ex vivo metastasis model. Further, we propose a novel mechanism underlying the disorganization of a metastasized bone matrix: A dynamic collision behavior between tumor cells and osteoblasts disturbs the osteoblast arrangement along the collagen substrate.

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Mr. Ozasa (D3) and Mr. Okuda (M1) won the Most Best Poster Award, and Mr. Kobayashi (M1), Mr. Sasaki, Mr. Harada, and Mr. Moriguchi (M1) won the Best Poster Award at the 1st Japan Institute of Metals and Materials 4th Field Conference.

The Most Best Poster Award
〇Ryosuke Ozasa, Takuya Ishimoto, Sayaka Miyabe, Jun Hashimoto, Hideki Yoshikawa, and Takayoshi Nakano:
Collagen/apatite orientation changes in vertebrae of osteoporotic rats.

〇Natsuki Okuda, Takuya Ishimoto, Masami Tanaka, Minoru Watanabe, Hitoshi Amano, and Takayoshi Nakano:
Elucidation of the relationship between endochondral ossification and bone matrix orientation

Best Poster Award
〇Yoshiya Kobayashi, Takuya Ishimoto, Hiroyuki Takahashi, Takayuki Inoue, Mitsuomi Kimura, Keita Uetsuki, Yoshio Nakajima, Manabu Ito, Takao Hanawa, and Takayoshi Nakano:
Novel vertebral body device design for induction of oriented bone matrix

〇Kyohei Sasaki, Ryosuke Kozasa, and Takayoshi Nakano:
Contribution of Apolipoprotein E to the Regulation of Bone Orientation

〇Tatsuki Harada, Aira Matsugaki, Takayoshi Nakano:
Regulatory behavior of osteoblast arrays based on intercellular signals with cancer cells.

〇Atsushi Moriguchi, Ryosuke Ozasa, Aira Matsugaki, Takayoshi Nakano:
Involvement of osteoclast-derived factors in bone tissue orientation

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Our collaborative research with Hagiwara Lab on strengthening of Mg alloys has been published in Acta Materialia as an open access journal.

Koji Hagihara, Zixuan Lia, Michiaki Yamasaki, Yoshihito Kawamura, Takayoshi Nakano:
Strengthening mechanisms acting in extruded Mg-based long-period stacking ordered (LPSO)-phase alloys,
Acta Materialia: volume163, pages 226-239.
https://doi.org/10.1016/j.actamat.2018.10.016

Abstract

The unusual increase in the strength by extrusion is a unique feature of recently developed Mg alloys containing the LPSO phase. In this study, we first elucidated the detailed mechanisms that induce this drastic strengthening. The dependencies of the deformation behavior of a Mg88Zn4Y7 extruded alloy, which contains ∼86-vol% LPSO phase, on the temperature, loading orientation, and extrusion ratio were examined. It was found that the yield stress of the alloy is drastically increased by extrusion, but the magnitude of the increase in the yield stress is significantly different depending on the loading orientation. That is, the strengthening of the LPSO phase by extrusion shows a strong anisotropy. By the detailed analyses, this was clarified to be derived from the variation in the deformation mechanisms depending on the loading orientation and extrusion ratio. Basal slip was found to govern the deformation behavior when the loading axis was inclined at a 45° to the extrusion direction, while the predominant deformation mechanism varies from basal slip to the formation of deformation kink bands as the extrusion ratio increased when the loading axis was parallel to the extrusion direction. Moreover, it was clarified in this study that the introduction of a deformation-kink-band boundary during extrusion effectively acts as a strong obstacle to basal slip. That is, "the kink band strengthening" was first quantitatively elucidated, which contributes to the drastic increase in the yield stress of the extruded LPSO-phase alloys in the wide temperature range below 400 °C.

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Our paper on bio-apatite crystal orientation in human edentulous mandibular anterior cortical bone with Tokyo Dental College has been published in JBMR-B.

Takehiro Furukawa,Satoru Matsunaga,Toshiyuki Morioka, Takayoshi Nakano, Shinichi Abe, Masao Yoshinari, Yasutomo Yajima:
Study on bone quality in the human mandible—Alignment of biological apatite crystallites,
Journal of Biomedical Materials Research Part B, 107B (2018) ,pp.838–846.
DOI: 10.1002/jbmb.34180

Abstract

The importance of considering bone quality during oral implant treatment is increasingly being recognized. Assessment of bone quality in response to changes in the jaw bone is extremely important when planning treatment. The present study analyzed biological apatite (BAp) crystallites, a bone quality factor, in order to investigate crystallographic anisotropy in dentate and edentulous human mandibles. Using mandibular samples from Japanese adult cadavers, a region of interest was established comprising cortical bone in the central incisors. Samples were classified into five morphological categories based on the extent of bone resorption. Bone mineral density (BMD) was measured and diffraction intensity ratios were calculated using a microbeam X‐ray diffraction system. While no differences were observed in BMD, differences were observed in BAp crystallite alignment between the measurement points. In the alveolar region, samples with residual alveolar bone showed strong alignment in the occlusal direction, while samples with marked alveolar bone resorption had preferential alignment in the mesiodistal direction. The present findings suggest that tooth loss and the extent of alveolar bone resorption affects bone quality in the mandible. © 2018 Wiley Periodicals, Inc. J. Biomed. Mater. Res. Part B: 2018.

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Our research on the improvement of strength and ductility of Co-Cr-Mo alloys by special low-temperature heat treatment, in collaboration with Narushima Lab. of Tohoku University, has been published in Materials Science and Engineering A as an open access

Kosuke Ueki*, Mai Abe, Kyosuke Ueda, Masaaki Nakai, Takayoshi Nakano and Takayuki Narushima:
Synchronous improvement in strength and ductility of biomedical Co–Cr–Mo alloys by unique low-temperature heat treatment,
Materials Science and Engineering: A Volume 739, pages 53-61. 
https://doi.org/10.1016/j.msea.2018.10.016

Abstract

The microstructure and tensile properties of Co–27Cr–6Mo (mass%) alloys heat-treated at 673–1373 K were studied. Lower elongation was observed after heat treatment at 1073 K due to formation of carbonitride precipitates. In contrast, when low-temperature heat treatment (LTHT) was applied at 673–873 K, both the ultimate tensile strength and elongation synchronously improved compared with the solution-treated alloy.Electron backcatter diffraction analysis for plastic-strained alloys and in situ X-ray diffraction analysis under stress-induced conditions revealed that the strain-induced martensitic transformation (SIMT) of the γ(fcc)-phase to ε(hcp)-phase during plastic deformation was suppressed by the LTHT. Stacking faults (thin ε-phase) were observed to collide in the LTHT alloys. The following mechanisms for the synchronous improvement in the tensile strength and elongation after LHTH are proposed. First, stacking faults with multiple variants were formed during LTHT. Then, the ε-phase of a single variant formed by SIMT during plastic deformation collides with preexisting multi-variant stacking faults formed during LTHT, increasing the tensile strength. In addition, the SIMT during plastic deformation is suppressed in the high-plastic-strain region by the collision. This decreases the total amount of ε-phase formed during plastic deformation, which improves the ductility. We demonstrated that LTHT of Co–Cr–Mo alloys effectively improves the performance and mechanical safety of spinal fixation implants, which often fracture because of fatigue cracking.

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A paper on the design of a novel vertebral cage has been published in the journal Clinical Biomechanics.

Hiroyuki Takahashi, Takuya Ishimoto, Yoshiya Kobayashi, Manabu Ito, Takayuki Inoue,Yoshio Nakashima, Takayoshi Nakano:
Design and development of spinal cage for rapid induction of new bone with preferential collagen/apatite orientation,
the journal Clinical Biomechanics, Vol.39 (2018), pp.199-206.

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Nakano Lab's article has been published in the October issue of "Applied Physics" (2018).

Takayoshi Nakano, Takuya Ishimoto:
Elucidation of the Oriented Structure of Bone Matrix from a Materials Perspective and Development of Bone Substitute Materials to Promote Bone Orientation,
Applied Physics, October, (2018).

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At the 163rd Annual Meeting of the Japan Institute of Metals, Dr. Nakano received the 16th Japan Institute of Metals and Materials Distinguished Achievement Award (Academic Division), Dr. Aiko Sekita, Dr. Aira Matsugaki, and Dr. Takayoshi Nakano received

At the 163rd Annual Meeting of the Japan Institute of Metals, Dr. Nakano received the 16th Japan Institute of Metals and Materials Distinguished Achievement Award (Academic Division), Dr. Aiko Sekita, Dr. Aira Matsugaki, and Dr. Takayoshi Nakano received the 66th Japan Institute of Metals and Materials The Best Paper Award(Microstructure Division), Dr. Naoko Ikeo (currently Assistant Professor at Kobe University) received the 28th Japan Institute of Metals and Materials Young Researcher Award, and Mr. Yasutomi (M2) received the 31st Japan Institute of Metals and Materials The Metals Best Poster Award.

〇Takayoshi Nakano:
the 16th Japan Institute of Metals and Materials Distinguished Achievement Award (Academic Division), the 163rd Annual Meeting of the Japan Institute of Metals, 2018/9/19.

〇Aiko Sekita, Aira Matsugaki and Takayoshi Nakano:
Structural crosstalk between crystallographic anisotropy in bone tissue and vascular network analyzed with a novel visualization method,(Materials Transactions, 58 [2], (2017), pp. 266-270.),
the 66th Japan Institute of Metals and Materials The Best Paper Award(Microstructure Division), the 163rd Annual Meeting of the Japan Institute of Metals, 2018/9/19.

〇Naoko Ikeo:
28th Japan Institute of Metals and Materials Young Researcher Award, the 163rd Annual Meeting of the Japan Institute of Metals, 2018/9/19.

〇Jumpei Yasutomi:
the 31st Japan Institute of Metals and Materials The Metals Best Poster Award, the 163rd Annual Meeting of the Japan Institute of Metals, 2018/9/19.

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Our paper on laser additive manufacturing of SUS316L steel has been published in "Scripta Materialia" as an open access journal.

Shi-Hai Sun, Takuya Ishimoto#, Koji Hagihara, Yusuke Tsutsumi, Takao Hanawa, Takayoshi Nakano*:
Excellent mechanical and corrosion properties of austenitic stainless steel with a unique crystallographic lamellar microstructure via selective laser melting,
Scripta Materialia, 159 (2018), pp.89-93. These authors(#) contributed equally to this work.

Abstract

We first developed a unique “crystallographic lamellar microstructure” (CLM), in which two differently oriented grains appear alternately, in a 316L stainless steel specimen via selective laser melting technology. The CLM was composed of major 〈011〉 grains and minor 〈001〉 grains aligned along the build direction, which stemmed from vertical and approximately ±45° inclined columnar cells formed in the central and side parts of melt-pools, respectively. The development of CLM was found to largely improve the material properties via the strengthening of the product, simultaneously showing superior corrosion resistance to commercially obtained specimens.

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Our paper on biomimetic calcification, which is a collaborative research with Okayama University, has been published in Journal of Materials Chemistry B as an open access journal.

Emilio Hara, Masahiro Okada, Takuo Kuboki, Takayoshi Nakano, Takuya Matsumoto*: 
Rapid bioinspired mineralization using cell membrane nanofragments and alkaline milieu,
Journal of Materials Chemistry B, (2018),
DOI: 10.1039/c8tb01544a

Abstract

Bone is a sophisticated organic–inorganic hybrid material, whose formation involves a complex spatiotemporal
sequence of events regulated by the cells. A deeper understanding of the mechanisms behind
bone mineralization at different size scales, and using a multidisciplinary approach, may uncover novel
pathways for the design and fabrication of functional bone tissue in vitro. The objectives of this study
were first to investigate the environmental factors that prime initial mineralization using the secondary
ossification center as an in vivo model, and then to apply the obtained knowledge for rapid in vitro
synthesis of bone-like tissue. First, the direct and robust measurement of pH showed that femur
epiphysis is alkaline (pH D 8.5) at the initial mineral stage at post-natal day 6. We showed that the
alkaline milieu is decisive not only for alkaline phosphatase activity, which precedes mineral formation at
P6, but also for determining initial mineral precipitation and spherical morphology. Next, engineering
approaches were used to synthesize bone-like tissue based on alkaline milieu and artificial chondrocyte
membrane nanofragments, previously shown to be the nucleation site for mineral formation.
Interestingly, mineralization using artificial cell membrane nanofragments was achieved in just 1 day.
Finally, ex vivo culture of femur epiphysis in alkaline pH strongly induced chondrocyte burst, which was
previously shown to be the origin of chondrocyte membrane nanofragments, and also enhanced
mineral formation. Taken together, these findings not only shed more light on the microenvironmental
conditions that prime initial bone formation in vivo, but they also show that alkaline milieu can be used
as an important factor for enhancing methods for in vitro synthesis of bone tissue.

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The results of the collaborative research between Hagiwara Lab. and Nakano Lab. were introduced in the magazine "Choice" as "Research on 'Superalloys' that contribute to improving thermal efficiency.

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The results of our collaboration with a group in India on DDS of two types of growth factors were published online in Acta Biomaterialia.

Manitha Nair*, Shruthy Kuttappan, Dennis Mathew, Jun-ichiro Jo, Ryusuke Tanaka, Deepthy Menon, Takuya Ishimoto, Takayoshi Nakano, Shantikumar V Nair, Yasuhiko Tabata:
Dual release of growth factor from a nanocomposite fibrous scaffold promotes vascularisation and bone regeneration in a rat critical sized calvarial defect,
Acta Biomater., anailable online 29 Jul , Vol 78(2018), pp.36-47.
doi: 10.1016/j.actbio.2018.07.050. [Epub ahead of print]

Abstract
A promising strategy for augmenting bone formation involves the delivery of multiple osteoinductive and vasculogenic growth factors locally. However, success depends on sustained growth factors release and its appropriate combination to induce stem cells and osteogenic cells at the bony site. Herein, we have developed a nanocomposite fibrous scaffold loaded with fibroblast growth factor 2 (FGF2) and bone morphogenetic protein 2 (BMP2) and its ability to promote vascularisation and bone regeneration in critical sized calvarial defect was compared to the scaffold with vascular endothelial growth factor (VEGF) + BMP2. Simple loading of growth factors on the scaffold could provide a differential release pattern, both in vitro and in vivo (VEGF release for 1 week where as BMP2 and FGF2 release for 3 weeks). Among all the groups, dual growth factor loaded scaffold (VEGF+BMP2 & FGF2+BMP2) enhanced vascularisation and new bone formation, but there was no difference between FGF2 and VEGF loaded scaffolds although its release pattern was different. FGF2 mainly promoted cell migration, whereas VEGF augmented new blood vessel formation at the defect site. This study suggests that biomimetic nanocomposite scaffold is a promising growth factor delivery vehicle to improve bone regeneration in critical sized bone defects.

Statement of Significance
Many studies have shown the effect of growth factors like VEGF-BMP2 or FGF2-BMP2 in enhancing bone formation in critical sized defects, but there are no reports that demonstrate the direct comparison of VEGF-BMP2 and FGF2-BMP2. In this study, we have developed a nanocomposite fibrous scaffold that could differentially release growth factors like VEGF, BMP2 and FGF2 (VEGF release for 1 week where as BMP2 and FGF2 release for 3 weeks), which in turn promoted neovascularisation and new bone formation in critical size defect. There was no difference in vascularisation and bone formation induced by VEGF+BMP2 or FGF2+BMP2. The growth factor was loaded in a simple manner, which would ensure ease of use for the end-user, especially for the surgeon treating a patient in an operating room.

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Our collaborative research with the Department of Conservative Medicine, Graduate School of Dentistry, Osaka University was published in the journal Clinical Oral Investigations.

Motoki Okamoto, Yusuke Takahashi, Shungo Komichi, Manahil Ali, Naomichi Yoneda, Takuya Ishimoto, Takayoshi Nakano, Mikako Hayashi:
Novel evaluation method of dentin repair by direct pulp capping using high-resolution micro-computed tomography,
Clinical Oral Investigations, (2018) pp.1-9

Abstract

Objectives
We evaluated a novel micro-computed tomography (micro-CT) assessment for quality and quantity of dentin repair, which is difficult to visualize by histological analysis, after direct pulp capping under standardized cavity preparation.

Materials and methods
Standardized cavities were prepared on Wistar rats and direct pulp capping was performed using two commercial bioceramics, ProRoot MTA, and iRoot BP Plus. After 2 or 4 weeks, quality and quantity of tertiary dentin formation were evaluated using high-resolution micro-CT analyses including dentin mineral density, dentin mineral contents, compactness and integrity of tertiary dentin, and dentin volume with/without void space. Reproducibility of micro-CT analyses was confirmed by histological evaluation of the same specimen.

Results
The exposed pulp area sizes were similar between iRoot BP Plus and ProRoot MTA. Micro-CT analysis of 2-week samples showing compactness of tertiary dentin was significantly higher in iRoot BP Plus than ProRoot MTA (p < 0.05). Tertiary dentin volume without void space, dentin mineral contents, and density were not significantly different between the groups. In 4-week samples, a significant increase was observed in dentin mineral density, compactness, and dentin volume with/without void space induced by iRoot BP Plus (p < 0.05). Micro-CT analysis of tertiary dentin integrity demonstrated that some ProRoot MTA specimens had small defects and lacked continuity (6/512 images). No defects were observed with iRoot BP Plus.

Conclusions
Micro-CT analysis was confirmed as an accurate, objective, and inclusive approach for evaluating quality and quantity of dentin repair.

Clinical relevance
These multifaceted approaches to evaluate pulp capping materials may accelerate review processes, ultimately improving vital pulp therapy.

Keywords
Micro-computed tomography evaluation Direct pulp capping iRoot BP Plus Mineral trioxide aggregate

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Our paper with Dr. Pan Wang, who is active in Singapore, has been published in "JALCOM" as an open access journal.

Pan Wang*, Mitsuharu Todai, Takayoshi Nakano*;
ω-phase transformation and lattice modulation in biomedicalβ-phase Ti-Nb-Al alloys,
Journal of Alloys and Compounds,766, (2018) pp.511-516.

Abstract

Athermal ω-phase transformation and the appearance of the lattice modulation in Ti-28Nb-xAl alloys were investigated by electrical resistivity measurements and transmission electron microscopy (TEM) observations. As a result, the athermal ω-phase is gradually suppressed with increasing Al content. In addition, the lattice modulation is also observed in Ti-28Nb-xAl alloys (0 ≤ x ≤ 7, in at.%) because of the transverse wave with a propagation vector of q = 1/2[ζζ¯0]∗ and displacement in [110]. These results imply that the ω-phase can be controlled by addition of the Al content in Ti-Nb alloys, leading to the development of low Young's modulus β-phase Ti biomedical alloys single crystal.

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At the 38th Annual Meeting of the Japanese Society for Bone Morphometry, Mr. Ozasa (D3) was awarded the Academic Encouragement Award and Mr. Nakanishi (M2) was awarded the Young Investigator Award.

Ryosuke Ozasa, Kyohei Sasaki, and Takayoshi Nakano:
Contribution of Apolipoprotein E to the Regulation Mechanism of Bone Orientation,
the 38th Annual Meeting of the Japanese Society for Bone Morphometry Academic Encouragement Award, Osaka International House, June 23, 2018

Yohei Nakanishi, Aira Matsugaki, Takayoshi Nakano:
Mechanism of osteoblast and bone matrix orientation by nano-periodic surface structures,
the 38th Annual Meeting of the Japanese Society for Bone Morphometry, Osaka International House, June 23, 2018.

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A commentary on "Phosphate Invert Glasses in Biomaterials" has been published in Phosphorus Letter.

Seongho Lee, Takayoshi Nakano:
Phosphate Invert Glasses for Biomedical Application,
Phosphorus Letter, No.92 [6], (2018), 20-31.

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Collaborative research results on oxygen doping of Ti were published in Materials Transactions.

Qiang Li, Dong Ma, Junjie Li, Mitsuo Niinomi, Masaaki Nakai, Yuichiro Koizumi, Daixiu Wei, Tomoyuki Kakeshita, Takayoshi Nakano, Akihiko Chiba, Kai Zhou, Deng Pan:
Low Young’s Modulus Ti-Nb-O with High Strength and Good Plasticity,
Materials Transactions,59 [5], (2018) pp.858-860.

Abstract

Oxygen was added to Ti–38Nb (mass%) alloys to improve their mechanical properties. Ti–38Nb–xO (x = 0.13, 0.24, 0.46, mass%) alloys were prepared by arc melting, and subsequently subjected to homogenization, hot rolling, and solution treatment. It was found that adding oxygen suppresses the martensite transformation and exhibits strong solution strengthening effect. Single β phase is obtained in Ti–38Nb–0.24O, whereas Ti–38Nb–0.13O is composed of both α′′ and β phases. Both alloys exhibit double yielding phenomena during tension, indicating a stress-induced martensitic transformation. Ti–38Nb–0.46O exhibits a non-linear deformation, a low Young’s modulus of 62 GPa, high tensile strength up to 780 MPa, and elongation around 23%, which are promising characteristics for biomedical applications.

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A paper on biological high-entropy alloys discovered in our laboratory has been published in the Journal of Alloys and Compounds (JALCOM) as an open access journal.

Takeshi Nagasea, Mitsuharu Todai, Takao Hori, Takayoshi Nakano:
Microstructure of equiatomic and non-equiatomic Ti-Nb-Ta-Zr-Mo high-entropy alloys for metallic biomaterials,
Journal of Alloys and Compounds (JALCOM), (2018), in press.
doi.org/10.1016/j.jallcom.2018.04.082

Abstract

Athermal ω-phase transformation and the appearance of the lattice modulation in Ti-28Nb-xAl alloys were investigated by electrical resistivity measurements and transmission electron microscopy (TEM) observations. As a result, the athermal ω-phase is gradually suppressed with increasing Al content. In addition, the lattice modulation is also observed in Ti-28Nb-xAl alloys (0 ≤ x ≤ 7, in at.%) because of the transverse wave with a propagation vector of q = 1/2[ζζ¯0]∗ and displacement in [110]. These results imply that the ω-phase can be controlled by addition of the Al content in Ti-Nb alloys, leading to the development of low Young's modulus β-phase Ti biomedical alloys single crystal

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An article introducing the results of Nakano Lab's research was posted on the website.

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A collaborative research paper with Narushima Laboratory, Tohoku University on deformation and corrosion of Co-Cr alloys due to unique microstructure formation by heat treatment has been published in Metallurgical and Materials Transactions A.

Kosuke Ueki, Kyosuke Ueda, Masaaki Nakai, Takayoshi Nakano, Takayuki Narushima:
Microstructural Changes During Plastic Deformation and Corrosion Properties of Biomedical Co-20Cr-15W-10Ni Alloy Heat-Treated at 873 K,
Metallurgical and Materials Transactions A, (2018) in press.
doi.org/10.1007/s11661-018-4597-0

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Dr. Nakano was awarded the 68th Japan Institute of Metals and Materials Metallography Award.

Koji Hagiwara, Takateru Ikenishi, Takayoshi Nakano:
Development of an unusual "cross-lamellar microstructure" in C40/C11b ultra-high temperature heat-resistant multiphase silicide alloys,
The 68th Japan Institute of Metals and Materials Metallography Award ([Division 2] Scanning Electron Microscopy Section "Award of Excellence"), Chiba Institute of Technology, March 19, 2018.

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Mr. Hori, who is currently an M2 student at Nakano Lab, received the Osaka University Industrial Association Award.

Takao Hori :
Development of novel bcc-type high-entropy alloys for biological applications

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An article about our laboratory's research was published in the March issue of Monthly Municipal Solutions (pages 69-71).

This article was written by Takeshi Hayashi of the Nikkan Kogyo Shimbun, and introduces the research of the Nakano Research Institute in the article "Implants open new horizons in bone fracture treatment and tooth reconstruction".

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Our collaborative research with Professor Takuya Matsumoto, Graduate School of Medical and Dental Sciences, Okayama University, which discovered a new bone formation mechanism in the early stage of calcification in secondary ossification, has been publish

(1) Emilio Satoshi Hara, Masahiro Okada, Noriyuki Nagaoka, Takako Hattori, Takuo Kuboki, Takayoshi Nakano, Takuya Matsumoto:
Bioinspired mineralization using chondrocyte membrane nanofragments,
ACS Biomaterials Science & Engineering, 4 [2] ,(2018) pp.617-625.

Abstract
Biomineralization involves complex processes and interactions between organic and inorganic matters, which are controlled in part by the cells. The objectives of this study were, first, to perform a systematic and ultrastructural investigation of the initial mineral formation during secondary ossification center of mouse femur based on material science and biology viewpoint, and then develop novel biomaterials for mineralization based on the in vivo findings. First, we identified the very initial mineral deposition at postnatal day 5 (P5) at the medial side of femur epiphysis by nanocomputed tomography. Initial minerals were found in the surroundings of hypertrophic chondrocytes. Interestingly, histological and immunohistochemical analyses showed that initial mineralization until P6 was based on chondrocyte activity only, i.e., it occurred in the absence of osteoblasts. Moreover, electron microscopy-based ultrastructural analysis showed that cell-secreted matrix vesicles were absent in the early steps of osteoblast-independent endochondral ossification. Instead, chondrocyte membrane nanofragments were found in the fibrous matrix surrounding the hypertrophic chondrocytes. EDS analysis and electron diffraction study indicated that cell membrane nanofragments were not mineralized material, and could be the nucleation site for the newly formed calcospherites. The phospholipids in the cell membrane nanofragments could be a source of phosphate for subsequent calcium phosphate formation, which initially was amorphous, and later transformed into apatite crystals. Finally, artificial cell nanofragments were synthesized from ATDC5 chondrogenic cells, and in vitro assays showed that these nanofragments could promote mineral formation. Taken together, these results indicated that cell membrane nanofragments were the nucleation site for mineral formation, and could potentially be used as material for manipulation of biomineralization.

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(2) Emilio Satoshi Hara, Masahiro Okada, Noriyuki Nagaoka, Takako Hattori, Takuo Kuboki, Takayoshi Nakano, Takuya Matsumoto:
Chondrocyte burst promotes space for mineral expansion,
Integrative Biology, 10 ,(2018) pp.57-66.

Abstract
Analysis of tissue development from multidisciplinary approaches can result in more integrative biological findings, and can eventually allow the development of more effective bioengineering methods. In this study, we analyzed the initial steps of mineral formation during secondary ossification of mouse femur based on biological and bioengineering approaches. We first found that some chondrocytes burst near the mineralized area. External factors that could trigger chondrocyte burst were then investigated. Chondrocyte burst was shown to be modulated by mechanical and osmotic pressure. A hypotonic solution, as well as mechanical stress, significantly induced chondrocyte burst. We further hypothesized that chondrocyte burst could be associated with space-making for mineral expansion. In fact, ex vivo culture of femur epiphysis in hypotonic conditions, or under mechanical pressure, enhanced mineral formation, compared to normal culture conditions. Additionally, the effect of mechanical pressure on bone formation in vivo was investigated by immobilization of mouse lower limbs to decrease the body pressure onto the joints. The results showed that limb immobilization suppressed bone formation. Together, these results suggest chondrocyte burst as a novel fate of chondrocytes, and that manipulation of chondrocyte burst with external mechano-chemical stimuli could be an additional approach for cartilage and bone tissue engineering.

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Our laboratory's commentary on bone and osteoarticular medical devices using metal 3D printers was published in Clinical Orthopedics.

Takayoshi Nakano, Takuya Ishimoto, Ryosuke Ozasa, Eiji Fukuda:
Advanced status of metal 3D printing : Toward application to bone and osteoarticular field,
Clinical Orthopaedics, Vol. 53 [2] (2018), pp. 137-144.

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A study on fatigue properties of TiAl with special layers formed by electron beam additive manufacturing (EBM) has been published in Intermetallics (Elsevier).

Ken Cho, Ryota Kobayashi, Jong Yeong Oh, Hiroyuki Y. Yasuda, Mitsuharu Todai, Takayoshi Nakano, Ayako Ikeda, Minoru Ueda, Masao Takeyama:
Influence of unique layered microstructure on fatigue properties of Ti-48Al2Cr-2Nb alloys fabricated by electron beam melting,
Intermetallics, 95, (2018), 1-10.

Abstract
The influence of a unique layered microstructure consisting of duplex-like region and equiaxed γ grain layers (γ bands) on the fatigue properties of Ti-48Al-2Cr-2Nb alloy bars fabricated by electron beam melting (EBM) was investigated at room temperature (RT) and 1023 K focusing on the angle (θ) between the building direction and cylinder (loading) axis. We found for the first time the fatigue strengths of the alloy bars with the layered microstructure depend strongly on the angle θ. Particularly, the fatigue strength of the alloy bars fabricated at θ = 45° is comparable to that of the hot isostatic pressing (HIP) treated cast alloys, even without HIP treatment. We also found the alloy bars fabricated at θ = 0° and 45° exhibit high fatigue strengths in the low-cycle fatigue life region at 1023 K similar to θ = 45° alloy bars at RT. These high fatigue strengths are caused by inhibition of the brittle main crack initiation by stress relaxation due to shear deformation at the γ bands and large plasticity of the alloys. These findings indicate that the alloys fabricated by EBM at θ = 45° with the unique layered microstructure have a great potential for aerospace and automobile applications.

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A paper on the analysis of substrate orientation in vascular mesomembranes has been published early in the Journal of the Japan Institute of Metals and Materials.

Ryosuke Ozasa, Takeru Nagaishi, Daisuke Yamazaki, Aira Matsugaki, Machiko Kanzaki, Toru Kuratani, Eiichi Morii, Yasushi Sakata, Takayoshi Nakano*:
Establishment of a quantitative analysis method for elucidating collagen/elastin fibril orientation in vascular tunica media,
Journal of the Japan Institute of Metals and Materials, 82 [3], (2018),
DOI:10. 2320/jinstmet.J2017060.

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A paper proving that long-term cigarette smoking with Keio University School of Medicine has a negative effect on bone quality was published in PLOS ONE as an open access journal.

Mamoru Sasaki, Shotaro Chubachi, Naofumi Kameyama, Minako Sato, Mizuha Haraguchi, Masaki Miyazaki, Saeko Takahashi, Takayoshi Nakano, Yukiko Kuroda, Tomoko Betsuyaku, Koichi Matsuo:
Effects of long-term cigarette smoke exposure on bone metabolism, structure, and quality in a mouse model of emphysema,
PLOS ONE, 13(1) (2018), e0191611.

Abstract
Smoking is a common risk factor for both chronic obstructive pulmonary disease (COPD) and osteoporosis. In patients with COPD, severe emphysema is a risk factor for vertebral fracture; however, the effects of smoking or emphysema on bone health remain largely unknown. We report bone deterioration in a mouse model of emphysema induced by nose-only cigarette smoke (CS) exposure. Unexpectedly, short-term exposure for 4-weeks decreased bone turnover and increased bone volume in mice. However, prolonged exposure for 20- and 40-weeks reversed the effects from suppression to promotion of bone resorption. This long-term CS exposure increased osteoclast number and impaired bone growth, while it increased bone volume. Strikingly, long-term CS exposure deteriorated bone quality of the lumbar vertebrae as illustrated by disorientation of collagen fibers and the biological apatite c-axis. This animal model may provide a better understanding of the mechanisms underlying the deterioration of bone quality in pulmonary emphysema caused by smoking.

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Mr. Sugimoto (M1) won the Best Poster Award at the 2nd Materials Science and Engineering Conference in 2018.

Shota Sugimoto, Takuya Ishimoto, Aira Matsugaki, Kiyoshi Yoshida, Dai Otsuki, Hideki Yoshikawa, and Takayoshi Nakano:
A novel bone regeneration method to promote orientation and mechanical function recovery of regenerated bone.

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An article on the results of the joint research with Hokkaido Medical Center and Tokyo Medical and Dental University to establish a method to evaluate bone health after spinal implant placement was published in the Nikkan Kogyo Shimbun on January 23.

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An article on the discovery of a new bone formation mechanism in the early stage of calcification in secondary ossification was published in the Asahi Shimbun on January 18 and the Nikkan Kogyo Shimbun on January 22.

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A comprehensive paper of our laboratory was published in "Japanese Journal of Polymer Science and Technology".

Aira Matsugaki, Takayoshi Nakano :
Induction of Bone Orientation Based on Cell Regulation by Medical Materials,
Japanese Journal of Polymer Science and Technology, Special Issue on Medical Polymers, Vol. 75, (2018), pp. 164-173.

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The 70th anniversary issue of "Production and Technology" contains an article on the high-tech promotion seminar organized by Prof. Nakano.

Takayoshi Nakano :
Construction of a 3D printer base in Kansai and creation of modeling objects by shape and material control.
Production and Technology, 70 [1], (2018), pp.19-26.

Click here for the 70th anniversary issue of "Production and Technology".
Click here for the article

Article Summary

Special Feature 2 (High-tech Promotion Seminar)
Revolution of "Manufacturing" by 3D Printer - What can be made and how? -
Introduction of lecturer:Nobuto Imanaka
Opening speech:Takayoshi Nakano
Establishment of a 3D printer base in Kansai and creation of modeling objects by shape and material control:Takayoshi Nakano
Trends of 3D manufacturing in Kansai companies - Changes brought by AM technology -:Takashi Matsushita
Fabrication of metal and ceramic structures by micro-particle paste photolithography:Toshihide Kirihara
Development of Medical Products by Electron Beam Additive Manufacturing :Takayuki Inoue
New Production Technology for Transportation Equipment and Energy Equipment by 3D Manufacturing :Kenichiro Igashira
Application of 3D printing technology in Panasonic and its future prospects :Masatoshi Teranishi

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2017

A paper demonstrating that osteoblasts differentiated from iPS cells can form oriented tissues has been published in the Journal of Biomedical Materials Research: Part A as an open access journal.

Ryosuke Ozasa, Aira Matsugaki, Yoshihiro Isobe, Taro Saku, Yun Hui-suk, Takayoshi Nakano*:
Construction of human induced pluripotent stem cell-derived oriented bone matrix microstructure by using in vitro engineered anisotropic culture model,
Journal of Biomedical Materials Research: Part A, 106 (2018), pp.360-369.
DOI: 10.1002/jbm.a.36238

Abstract
Bone tissue has anisotropic microstructure based on collagen/biological apatite orientation, which plays essential roles in the mechanical and biological functions of bone. However, obtaining an appropriate anisotropic microstructure during the bone regeneration process remains a great challenging. A powerful strategy for the control of both differentiation and structural development of newly-formed bone is required in bone tissue engineering, in order to realize functional bone tissue regeneration. In this study, we developed a novel anisotropic culture model by combining human induced pluripotent stem cells (hiPSCs) and artificiallycontrolled oriented collagen scaffold. The oriented collagen scaffold allowed hiPSCs-derived osteoblast alignment and further construction of anisotropic bone matrix which mimics the bone tissue microstructure. To the best of our knowledge, this is the first report showing the construction of bone mimetic anisotropic bone matrix microstructure from hiPSCs. Moreover, we demonstrated for the first time that the hiPSCs-derived osteoblasts possess a high level of intact functionality to regulate cell alignment.

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Our paper on the crystal orientation rotation mechanism in laser beam additive manufacturing of Ni₃Mo has been published in Materials & Design (Elsevier).

Shi-Hai Sun, Koji Hagihara, Takayoshi Nakano:
Effect of scanning strategy on texture formation in Ni-25 at.%Mo alloys fabricated by selective laser melting,
Materials & Design, 140 [15], (2018).

Abstract
Variations in the crystallographic texture in Ni-25 at.%Mo alloys fabricated by selective laser melting with different scanning strategies were designed for the first time. Single-crystalline-like texture with a short-range order of Mo atoms can be produced via bidirectional scanning along one axis (X-scan) and bidirectional scanning with a 90° rotation in each layer (XY-scan), while only fiber texture was formed in bidirectional scanning with a 67° rotation (Rot-scan). The aligned crystal orientation along the build direction can be varied by the scanning strategy; 〈001〉 is preferred in the XY- and Rot-scan samples, while 〈101〉 is preferred in the X-scan sample. The controlling mechanisms of the texture, focusing on the preferential growth directions of the columnar cells and the following epitaxial growth, are discussed.

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A collaborative study between our laboratory and Dr. Ito (Hokkaido Medical Center) and Dr. Hanawa (Tokyo Medical and Dental University), focusing on the methodology to evaluate the integrity of vertebral cages, has been published in the open access journa

Takuya Ishimoto, Katsuhisa Yamada, Hiroyuki Takahashi, Masahiko Takahata, Manabu Ito, Takao Hanawa, Takayoshi Nakano* :
Trabecular health of vertebrae based on anisotropy in trabecular architecture and collagen/apatite micro-arrangement after implantation of intervertebral fusion cages in the sheep spine,
Bone, 108 (2018), pp.25-33.
DOI : doi.org/10/1016/j.bone.2017.12.012

abstract

Healthy trabecular bone shows highly anisotropic trabecular architecture and the preferential orientation of collagen and apatite inside a trabecula, both of which are predominantly directed along the cephalocaudal axis. This makes trabecular bone stiff in the principally loaded direction (cephalocaudal axis). However, changes in these anisotropic trabecular characteristics after the insertion of implant devices remain unclear. We defined the trabecular architectural anisotropy and the preferential orientation of collagen and apatite as parameters of trabecular bone health. In the present study, we analyzed these parameters after the implantation of two types of intervertebral fusion cages, open and closed box-type cages, into sheep spines for 2 and 4 months. Alteration and evolution of trabecular health around and inside the cages depended on the cage type and implantation duration. At the boundary region, the values of trabecular architectural anisotropy and apatite orientation for the closed-type cages were similar to those for isotropic conditions. In contrast, significantly larger anisotropy was found for open-type cages, indicating that the open-type cage tended to maintain trabecular anisotropy. Inside the open-type cage, trabecular architectural anisotropy and apatite orientation significantly increased with time after implantation. Assessing trabecular anisotropy might be useful for the evaluation of trabecular health and the validation and refinement of implant designs.

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Our collaborative research with Nagasaki University and Dentistry on bone quality around dental implants under stress has been published in PLoS ONE as an open access journal.

Yusuke Uto, Shinichiro Kuroshima, Takayoshi Nakano, Takuya Ishimoto, Nao Inaba, Yusuke Uchida, Takashi Sawase:
Effects of mechanical repetitive load on bone quality around implants in rat maxillae,
PLoS ONE 12, (2017), paper No: e0189893.
DOI:10.1371/journal.pone.0189893

abstract

Greater understanding and acceptance of the new concept “bone quality”, which was pro-posed by the National Institutes of Health and is based on bone cells and collagen fibers, are required. The novel protein Semaphorin3A (Sema3A) is associated with osteoprotection by regulating bone cells. The aims of this study were to investigate the effects of mechanical loads on Sema3A production and bone quality based on bone cells and collagen fibers around implants in rat maxillae. Grade IV-titanium threaded implants were placed at 4 weeks post-extraction in maxillary first molars. Implants received mechanical loads (10 N, 3 Hz for 1800 cycles, 2 days/week) for 5 weeks from 3 weeks post-implant placement to mini-mize the effects of wound healing processes by implant placement. Bone structures, bone mineral density (BMD), Sema3A production and bone quality based on bone cells and collagen fibers were analyzed using microcomputed tomography, histomorphometry, immuno-histomorphometry, polarized light microscopy and birefringence measurement system inside of the first and second thread (designated as thread A and B, respectively), as mechanical stresses are concentrated and differently distributed on the first two threads from the implant neck. Mechanical load significantly increased BMD, but not bone volume around implants. Inside thread B, but not thread A, mechanical load significantly accelerated Sema3A production with increased number of osteoblasts and osteocytes, and enhanced production of both type I and III collagen. Moreover, mechanical load also significantly
induced preferential alignment of collagen fibers in the lower flank of thread B. These data demonstrate that mechanical load has different effects on Sema3A production and bone quality based on bone cells and collagen fibers between the inside threads of A and B. Mechanical load-induced Sema3A production may be differentially regulated by the type of bone structure or distinct stress distribution, resulting in control of bone quality around implants in jaw bones.

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Our joint commentary on metal additive manufacturing with Tohoku University was published in the December issue of Matelia (mini-feature article "Frontiers of Ultra-Precision 3D Additive Manufacturing Technology for Metallic Materials").

Yuichiro Koizumi, Akihiko Chiba, Naoyuki Nomura, and Takayoshi Nakano:
Fundamentals of 3D Additive Manufacturing Technology for Metallic Materials,
Matelia, 56 [12], (2017), pp. 686-690.

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Our laboratory's paper will be published in J. Ipn. Orthop. Assoc.

Takayoshi Nakano, Takuya Ishimoto:
Effect of Mechanical Stress on Bone Matrix Orientation and Its Predictive Potential,
Journal of J. Ipn. Orthop. Assoc., 91 (2017), pp. 959-967.

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At the 39th Annual Meeting of The Japanese Society for Biomaterials, Mr. Ozasa (D2) won the Journal of Materials Chemistry B Presentation Prize, and Mr. Nakanishi (M1) and Mr. Nagaishi (M1) won the Best Research Poster Award.

Journal of Materials Chemistry B Presentation Prize
〇Ryosuke Ozasa, Aira Matsugaki, Takayoshi Nakano :
Regulation of bone matrix orientation by osteoclasts

Excellent Research Poster Award
〇Yohei Nakanishi, Aira Matsugaki, Kosuke Kawahara, Takafumi Ninomiya, Hiroshi Sawada, Takayoshi Nakano :
Orientation mechanism of orthotropic bone matrix by nanoperiodic structure

〇Takeru Nagaishi, Ryosuke Ozasa, Machiko Kanzaki, Yasushi Sakata, Eiichi Morii, Toru Kuratani, Takayoshi Nakano :
Site dependence of anisotropic structure of vascular tunica media

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A commentary written mainly by Mr. Ozasa (D2) will be published in "Kagaku Kogyo".

Ryosuke Ozasa, Takuya Ishimoto, Takayoshi Nakano :
Biofunctionalization of biomaterials from the viewpoint of bone quality,
Chemical Industry, 68 [12], (2017), pp. 891-897.

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A column about Dr. Nakano appeared in the Nikkan Kogyo Shimbun.

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The results of our collaborative research with Professor Hayashi at Osaka University Graduate School of Dentistry were published in Scientific Reports, a Nature publication.

K. Yagi, H. Yamamoto, R. Uemura, Y. Matsuda, K. Okuyama, T. Ishimoto, T. Nakano, M. Hayashi:
Use of PIXE/PIGE for sequential Ca and F measurements in root carious model, Scientific Reports,7 (2017), srep13450.

Abstract

The progress of caries has conventionally been evaluated by checking changes in mineral density using transverse microradiography (TMR). Recent advances have seen development of a new measurement system, using in-air micro proton induced X-ray/gamma-ray emission (PIXE/PIGE). PIXE/PIGE enables analysis of distributions and concentrations of multiple mineral elements in a carious lesion. The aim of this study was to evaluate the effectiveness of PIXE/PIGE for investigating the development of root caries. In summary, we successfully established a multi-elemental sequential measuring method using in-air micro-PIXE/PIGE to identify the dynamic distributions and concentrations of Ca and F in human root dentin. The PIXE/PIGE potentially offers a useful advantageous technique for studying carious development by using as a combination with conventional techniques such as TMR and Micro-computed tomography (µCT).

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A paper demonstrating that osteoblasts differentiated from iPS cells can form oriented tissues has been published in the Journal of Biomedical Materials Research: Part A as an open access journal.

Ryosuke Ozasa, Aira Matsugaki, Yoshihiro Isobe, Taro Saku, Yun Hui-suk, Takayoshi Nakano*:
Construction of human induced pluripotent stem cell-derived oriented bone matrix microstructure by using in vitro engineered anisotropic culture model,
Journal of Biomedical Materials Research: Part A, (2017), in press.
DOI: 10.1002/jbm.a.36238

Abstract
Bone tissue has anisotropic microstructure based on collagen/biological apatite orientation, which plays essential roles in the mechanical and biological functions of bone. However, obtaining an appropriate anisotropic microstructure during the bone regeneration process remains a great challenging. A powerful strategy for the control of both differentiation and structural development of newly-formed bone is required in bone tissue engineering, in order to realize functional bone tissue regeneration. In this study, we developed a novel anisotropic culture model by combining human induced pluripotent stem cells (hiPSCs) and artificiallycontrolled oriented collagen scaffold. The oriented collagen scaffold allowed hiPSCs-derived osteoblast alignment and further construction of anisotropic bone matrix which mimics the bone tissue microstructure. To the best of our knowledge, this is the first report showing the construction of bone mimetic anisotropic bone matrix microstructure from hiPSCs. Moreover, we demonstrated for the first time that the hiPSCs-derived osteoblasts possess a high level of intact functionality to regulate cell alignment.

Click here for this paper.

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At the 161st Annual Meeting of the Japan Institute of Metals, Dr. Matsugaki received The 27th Japan Institute of Metals and Materials Young Researcher Award and our research received The 65th Japan Institute of Metals and Materials The Best Paper Award.

The 27th Japan Institute of Metals and Materials Young Researcher Award
Aira Matsugaki:
Research on the development of biomaterials for the construction of bone microstructures based on metallic materials science

The 65th Japan Institute of Metals and Materials The Best Paper Award
〇Aiko Sekita, Aira Matsugaki, Takayoshi Nakano:
Disruption of Collagen Matrix Alignment in Osteolytic Bone Metastasis Induced by Breast Cancer (Materials Transactions, Vol.57, No.12)

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We succeeded in fabricating epsilon (hcp) single crystals of Co-Cr-Mo alloy for biomedical applications, and our paper on the plastic deformation behavior using the single crystals was published in "Scripta Materialia" as an open access journal.

W. Kaita, K. Hagihara, L.A. Rocha, T. Nakano*:
Plastic deformation mechanisms of biomedical Co–Cr–Mo alloy single crystals with hexagonal close-packed structure,
Scripta Materialia, 142C, (2018), 111-115.

abstract
This is the first report of the successful fabrication of Co–Cr–Mo biomedical alloy single crystals with a hexagonal close-packed (hcp) structure and the resultant clarification of its deformation behavior. The (0001)〈11View the MathML source2¯0〉 basal and {1View the MathML source1¯00}〈11View the MathML source2¯0〉 prismatic slip systems were found to be predominately operative. The critical resolved shear stresses for the basal and prismatic slip systems at ambient temperature are ~ 204 and ~ 272 MPa, respectively, which are much higher than ~ 54 MPa for {111}〈11View the MathML source2¯〉 slip in the face-centered cubic (fcc) Co–Cr–Mo phase, quantitatively demonstrating that the hcp phase acts as an effective strengthening phase.

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A paper on the discovery of "dynamic precipitation softening" in the ω-phase of βTi has been published in the journal "Scientific Reports" published by nature.

The ω-phase of βTi is not necessarily hard, and depending on the reaction with dislocations, a completely opposite phenomenon called "dynamic precipitation softening" occurs, which was discovered and named. This research was published in the journal "Scientific Report" published by nature.

However, when the direction of precipitation and the direction of dislocation motion coincide, the precipitation of the ω-phase in βTi, which is brittle but strong, is promoted and the material is simultaneously softened.

K. Hagihara, T. Nakano*, M. Todai:
Unusual dynamic precipitation softening induced by dislocation glide in biomedical beta-titanium alloys,
Scientific Reports, 7 (2017), srep8056.

Abstract

Softening of metallic materials containing precipitates during cyclic deformation occurs through dissolution of the precipitates, because the to-and-fro motion of the dislocation causes dissolution of the precipitate particles by cutting them. Here, however, we found the completely opposite phenomenon for the first time; a “dynamic precipitation softening” phenomenon. In a Ti-35Nb-10Ta-5Zr body-centered cubic structured β-Ti alloy single crystal developed for biomedical implant, the to-and-fro motion of the dislocation “induced” the selective precipitation of the ω-phase whose c-axis is parallel to the Burgers vector of the moving dislocation, which led to the significant cyclic softening of the crystal. The formation of the ω-phase is generally believed to induce significant hardening of β-Ti alloys. However, the present results suggest that this is not always true, and control of the anisotropic features of the ω-phase via control of crystal orientation can induce unusual mechanical properties in β-Ti alloys. The unique anisotropic mechanical properties obtained by the cyclic-deformation-induced oriented ω-phase formation could be useful for the development of “single-crystalline β-Ti implant materials” with advanced mechanical performance.

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Our research on Ag-containing calcium phosphate invert glass has been published in the Journal of Biomedical Materials Research: Part A as an open access journal.

S. Lee T. Nakano T. Kasuga :
Structure, dissolution behavior, cytocompatibility, and antibacterial activity of silver-containing calcium phosphate invert glasses
Journal of Biomedical Materials Research: Part A, (2017)
DOI: doi.org/10.1002/jbm.a.36173

Abstract

Novel CaO-P2O5-Nb2O5-Ag2O invert glasses with substitution Ag2O for Nb2O5 were successfully prepared using a melt-quenching method. Ag2O in the glasses act as a network modifier oxide, playing the same role as Na2O, which breaks the phosphate chains. Analysis of the ultraviolet-visible absorption spectra of the glasses showed that the glass matrix contained ionic silver species and silver nanoparticles. Approximately 0.05 mM of Nb5+ ions released from the glasses, which would be expected to stimulate osteoblast differentiation. A glass containing 1 mol% Ag2O showed a linear increase in the releasing amount of Ag+ ions with increasing soaking time, whereas glasses containing 3–5 mol% Ag2O showed Ag+ ion concentrations of around 13 μM at day 3, and then maintained similar values until day 7. When the solution was replaced with fresh solution every 2 days, the Ag+ ion dissolution amounts indicated almost constantly 13 μM due to AgCl formation. There were no differences in the numbers of primary osteoblast cells on silver-free and silver-containing glasses after cultivation for 1–7 days. The silver-containing calcium phosphate invert glasses showed cytocompatibility with simultaneous antibacterial activity to Escherichia coli and Staphylococcus aureus.

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A paper on EBM in collaboration with Prof. Morita of Kyoto Institute of Technology has been published on-line in Materials Science and Engineering A.

T. Morita, C. Tsuda and T. Nakano:
Influences of scanning speed and short-time heat treatment on fundamental properties of Ti-6Al-4V alloy produced by EBM method, Materials Science and Engineering A, (2017), in press. 
DOI: https://doi.org/10.1016/j.msea.2017.08.020

Abstract

This study was conducted to examine the influence of the scanning speed of an electron beam on the fundamental properties of Ti-6Al-4V alloy produced by EBM (electron beam melting) method. We further investigated the effect of short-time heat treatment on those properties. By increasing the scanning speed, the desired outer shape was more closely achieved. However, molding defects became larger and the density reduced. On balance, the appropriate range of scanning speed was between 1 and 2 m/s. EBM materials had columnar microstructures elongated in the building direction. Although these characteristic microstructures were mainly composed of the stable α and β phases, the α' phase was partially generated at high scanning speed. By increasing the scanning speed, the amount of the α' phase increased and the hardness rose. The short-time heat treatment generated the fine α' and α phases in the prior β phase. This microstructural change markedly increased the hardness of EBM material.

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Our paper on the regulation of osteoblast sequencing from young mice has been published in the Journal of the Japan Institute of Metals and Materials.

Ryosuke Ozasa, Aira Matsukaki, Hitohiro Isobe, Taro Saku, Takayoshi Nakano* :
Regulation of young mouse osteoblast alignment by anisotropic collagen substrates,
Journal of the Japan Institute of Metals and Materials (2017)

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A paper on the correlation between bone matrix anisotropy and the vascular network in bone has been published in Materials Transactions as an open access journal.

A. Sekita A. Matsugaki T. Nakano :
Structural Crosstalk between Crystallographic Anisotropy in Bone Tissue and Vascular Network Analyzed with a Novel Visualization Method,
Materials Transactions, Vol.58 [2] (2017) , pp.266-270

abstract

Bone tissue has a highly anisotropic microstructure derived from the crystallographic orientation of apatite and the related collagen matrix alignment. Bone is also a highly vascularized tissue; intraosseous vascularization and bone formation are intimately coupled. Meanwhile, the structural relations between intraosseous vascular networks and bone microstructure are as yet unknown, partially due to technical dif­culties in visualizing precise intraosseous vasculatures. The aim of this study is to develop a visualization method suitable for the structural analysis of intraosseous vascular networks and to reveal the relations between bone microstructure and the arrangement patterns of intraosseous vasculatures. Three-dimensional vascular networks were successfully visualized, and region-dependent arrangement patterns of blood vessels were clari­ed using ‑uorescent dye-conjugated lectin. Interestingly, the anisotropic structural correlation between bone matrix and the vascular system in a region-speci­c manner was clari­ed. The obtained results indicate the molecular interactions between the vascular system and bone tissue as a novel contributor for realization of anisotropic bone matrix construct.

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An article on the development of ultra-high temperature resistant materials is published in the column section of Tsukuba Science News.

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Dr. Todai delivered a lecture at the Chu-Shikoku Branch Meeting of the Japan Institute of Light Metals, and received the Research and Development Encouragement Award.

July 29 (Sat) The Japan Institute of Light Metals, Chu-Shikoku Section Lecture Meeting
Mitsuyo Todai, Takao Hori, Takeshi Nagase, Koji Hagiwara, Takayoshi Nakano:
Beta-Ti Alloying and Crystal Orientation Control by Laser Additive Manufacturing

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A paper showing that both bone matrix orientation and mechanical function are reduced in c-src KO mice has been published in Bone.

T. Ishimoto, B. Sato, J. -W. Lee, T. Nakano*:
Co-deteriorations of anisotropic extracellular matrix arrangement and intrinsic mechanical property in c-src deficient osteopetrotic mouse femur,
Bone, 103C (2017), pp.216-223
DOI : //doi.org/10.1016/j.bone.2017.06.023

abstract

Osteopetrotic bone shows dissociation between bone mineral density (BMD) and bone strength. In this study, volumetric BMD; preferential orientation of the extracellular matrix (ECM), which is composed of collagen fibers and apatite crystals as bone material quality; and mechanical properties of the src−/− osteopetrotic and normal mouse femoral cortical bone were analyzed and compared with each other at a bone tissue level. The degree of preferential orientation of ECM along the femoral long axis was significantly decreased in the src−/− mice femur, suggesting deteriorated bone quality. Young's modulus, as a tissue-level mechanical property analyzed by nano-indentation technique along the long bone direction, also was decreased in the src−/− mice cortical femur, in spite of the similar volumetric cortical BMD. To the best of our knowledge, this is the first report to demonstrate the synchronous deterioration of Young's modulus and anisotropic ECM organization in the src−/− osteopetrotic mouse bone. These results indicate that the deterioration of the preferential ECM orientation is one major cause of the impaired mechanical property in the src−/− mouse bone.

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Our paper on unstable β-alloy single crystals has been published online with open access in International Journal of Plasticity.

K. Hagihara, T. Nakano*:
Experimental clarification of the cyclic deformation mechanisms of β-type Ti–Nb–Ta–Zr-alloy single crystals developed for the single-crystalline implant,
International Journal of Plasticity, (2017)
DOI : doi.org/10.1016/j.ijplas.2017.06.006.

Abstract

Quaternary Ti-Nb-Ta-Zr (TNTZ) type β-Ti alloys with a body-centered cubic (bcc) structure have been of great interest as new implant biomaterials for bone replacement. Recently, we have proposed a “single crystalline β-Ti implant” as a novel hard-tissue replacement to suppress the stress shielding to bone after healing. To develop this, the fatigue properties and its controlling mechanisms of the TNTZ single crystals must be clarified. In this study, we focused on three alloys: Ti-25Nb-10Ta-5Zr(25Nb), Ti-29Nb-13Ta-4.6Zr(29Nb), and Ti-35Nb-10Ta-5Zr(35Nb) (mass%), and the cyclic deformation behaviors were examined using their single crystals. The shapes of the hysteresis loops were significantly different for these alloys, which was ascribed to the operation of different deformation modes: stress-induced α”-martensite ( α”-SIM), {332}<113> twinning, and {101}<111> slip in the 25Nb, 29Nb, and 35Nb alloys, respectively. The hysteresis loops during cyclic deformation exhibited very irregular shapes for 25Nb and 29Nb, accompanied by a flow-stress asymmetry in tension and compression. This was caused by the polarized feature on the formation of them in tension and compression. In addition, the apparent yield stress in a hysteresis loop greatly decreased after the second cycle, owing to the reversible motion of the interfaces of the SIM and {332} twins by altering the direction of the applied stress. Although the cyclic deformation behavior was controlled by a similar mechanism in them, 29Nb was found to exhibit a much shorter fatigue life than 25Nb. This is because of the difference in the decreasing tendency of the reversibility for the SIM and {332} twins as cyclic deformation proceeded. The obtained results demonstrate that the controls of their asymmetric features and the reversible motion are the important factors to develop these alloys as a practical “single crystalline β-Ti implant”.

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Our paper on unstable β-alloy single crystals has been published online with open access in International Journal of Plasticity.

K. Hagihara, T. Nakano*:
Experimental clarification of the cyclic deformation mechanisms of β-type Ti–Nb–Ta–Zr-alloy single crystals developed for the single-crystalline implant,
International Journal of Plasticity, (2017)
DOI : doi.org/10.1016/j.ijplas.2017.06.006.

Abstract

Quaternary Ti-Nb-Ta-Zr (TNTZ) type β-Ti alloys with a body-centered cubic (bcc) structure have been of great interest as new implant biomaterials for bone replacement. Recently, we have proposed a “single crystalline β-Ti implant” as a novel hard-tissue replacement to suppress the stress shielding to bone after healing. To develop this, the fatigue properties and its controlling mechanisms of the TNTZ single crystals must be clarified. In this study, we focused on three alloys: Ti-25Nb-10Ta-5Zr(25Nb), Ti-29Nb-13Ta-4.6Zr(29Nb), and Ti-35Nb-10Ta-5Zr(35Nb) (mass%), and the cyclic deformation behaviors were examined using their single crystals. The shapes of the hysteresis loops were significantly different for these alloys, which was ascribed to the operation of different deformation modes: stress-induced α”-martensite ( α”-SIM), {332}<113> twinning, and {101}<111> slip in the 25Nb, 29Nb, and 35Nb alloys, respectively. The hysteresis loops during cyclic deformation exhibited very irregular shapes for 25Nb and 29Nb, accompanied by a flow-stress asymmetry in tension and compression. This was caused by the polarized feature on the formation of them in tension and compression. In addition, the apparent yield stress in a hysteresis loop greatly decreased after the second cycle, owing to the reversible motion of the interfaces of the SIM and {332} twins by altering the direction of the applied stress. Although the cyclic deformation behavior was controlled by a similar mechanism in them, 29Nb was found to exhibit a much shorter fatigue life than 25Nb. This is because of the difference in the decreasing tendency of the reversibility for the SIM and {332} twins as cyclic deformation proceeded. The obtained results demonstrate that the controls of their asymmetric features and the reversible motion are the important factors to develop these alloys as a practical “single crystalline β-Ti implant”.

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A commentary on recent achievements in metal AM (3D printer) was published by the Japan Society of Powder and Powder Metallurgy.

Takayoshi Nakano, Takuya Ishimoto, Koji Hagiwara :
Adding Anisotropy by Controlling Shape and Microstructure Using Powder Additive Manufacturing Method,
J. Jpn. Soc. Powder Metallurgy, Vol.64 [6] (2017) pp.259-264.

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Our laboratory's article on shape and material control by metal 3D printer technology was published in "Mechanical Technology".

Takayoshi Nakano :
Medical Application by Shape and Material Control Using Metal 3D Printer,
Mechanical Engineering, Vol.65 [8] (2017), pp.30-35

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Our collaborative research with Hagiwara Lab. of Osaka University was published in "International Journal of Plasticity".

K. Hagihara, T. Nakano*:
Experimental clarification of the cyclic deformation mechanisms of β-type Ti–Nb–Ta–Zr-alloy single crystals developed for the single-crystalline implant,
International Journal of Plasticity, (2017) pp.27-44.

Abstract

Quaternary Ti–Nb–Ta–Zr (TNTZ) type β-Ti alloys with a body-centered cubic (bcc) structure have been of great interest as new implant biomaterials for bone replacement. Recently, we have proposed a “single crystalline β-Ti implant” as a novel hard-tissue replacement to suppress the stress shielding to bone after healing. To develop this, the fatigue properties and its controlling mechanisms of the TNTZ single crystals must be clarified. In this study, we focused on three alloys: Ti–25Nb–10Ta–5Zr(25Nb), Ti–29Nb–13Ta–4.6Zr(29Nb), and Ti–35Nb–10Ta–5Zr(35Nb) (mass%), and the cyclic deformation behaviors were examined using their single crystals. The shapes of the hysteresis loops were significantly different for these alloys, which was ascribed to the operation of different deformation modes: stress-induced α”-martensite (α”-SIM), {332}<113> twinning, and {101}<111> slip in the 25Nb, 29Nb, and 35Nb alloys, respectively. The hysteresis loops during cyclic deformation exhibited very irregular shapes for 25Nb and 29Nb, accompanied by a flow-stress asymmetry in tension and compression. This was caused by the polarized feature on the formation of them in tension and compression. In addition, the apparent yield stress in a hysteresis loop greatly decreased after the second cycle, owing to the reversible motion of the interfaces of the SIM and {332} twins by altering the direction of the applied stress. Although the cyclic deformation behavior was controlled by a similar mechanism in them, 29Nb was found to exhibit a much shorter fatigue life than 25Nb. This is because of the difference in the decreasing tendency of the reversibility for the SIM and {332} twins as cyclic deformation proceeded. The obtained results demonstrate that the controls of their asymmetric features and the reversible motion are the important factors to develop these alloys as a practical “single crystalline β-Ti implant”.

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An article on the results of the development of ultra-high temperature resistant materials was published in the Nikkan Kogyo Shimbun on June 22.

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Dr. Hagiwara's research on the development of ultra-high temperature resistant materials was published in Scientific Reports (narure publishing), and he made a press announcement.

K. Hagihara, T. Ikenishi, H. Araki, T. Nakano:
Outstanding compressive creep strength in Cr/Ir-codoped (Mo0.85Nb0.15)Si2 crystals with the unique cross-lamellar microstructure,
Scientific Reports, 7 : 3936, (2017)

Abstract

A (Mo0.85 Nb0.15)Si2 crystal with an oriented, lamellar, C40/C11b two-phase microstructure is a promising ultrahigh-temperature (UHT) structural material, but its low room-temperature fracture toughness and low high-temperature strength prevent its practical application. As a possibility to overcome these problems, we first found a development of unique “cross-lamellar microstructure”, by the cooping of Cr and Ir. The cross-lamellar microstructure consists of a rod-like C11b-phase grains that extend along a direction perpendicular to the lamellar interface in addition to the C40/C11b fine lamellae. In this study, the effectiveness of the cross-lamellar microstructure for improving the high-temperature creep deformation property, being the most essential for UHT materials, was examined by using the oriented crystals. The creep rate significantly reduced along a loading orientation parallel to the lamellar interface. Furthermore, the degradation in creep strength for other loading orientation that is not parallel to the lamellar interface, which has been a serious problem up to now, was also suppressed. The results demonstrated that the simultaneous improvement of high-temperature creep strength and room temperature fracture toughness can be first accomplished by the development of unique cross- lamellar microstructure, which opens a potential avenue for the development of novel UHT materials as alternatives to existing Ni-based superalloys.

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当研究室が共著となった骨質のreviewが、Journal of Prosthodontic Researchに掲載されました。

S. Kuroshima, M. Kaku, T. Ishimoto, M. Sasaki, T. Nakano, T. Sawase:
A Paradigm Shift for Bone Quality in Dentistry: A Literature Review,
Journal of Prosthodontic Research, (2017)
DOI:10.1016/j.jpor.2017.05.006

Abstract

PURPOSE:
The aim of this study was to present the current concept of bone quality based on the proposal by the National Institutes of Health (NIH) and some of the cellular and molecular factors that affect bone quality.

STUDY SELECTION:
This is a literature review which focuses on collagen, biological apatite (BAp), and bone cells such as osteoblasts and osteocytes.

RESULTS:
In dentistry, the term "bone quality" has long been considered to be synonymous with bone mineral density (BMD) based on radiographic and sensible evaluations. In 2000, the NIH proposed the concept of bone quality as "the sum of all characteristics of bone that influence the bone's resistance to fracture," which is completely independent of BMD. The NIH defines bone quality as comprising bone architecture, bone turnover, bone mineralization, and micro-damage accumulation. Moreover, our investigations have demonstrated that BAp, collagen, and bone cells such as osteoblasts and osteocytes play essential roles in controlling the current concept of bone quality in bone around hip and dental implants.

CONCLUSION:
The current concept of bone quality is crucial for understanding bone mechanical functions. BAp, collagen and osteocytes are the main factors affecting bone quality. Moreover, mechanical loading dynamically adapts bone quality. Understanding the current concept of bone quality is required in dentistry.

Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

KEYWORDS:
Biological apatite (BAp); Bone quality; Collagen; Osteocytes; Prosthodontic dentistry

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Many of the papers published by the Nakano Institute have been announced as Most downloaded articles.

<Scripta Materialia>

(3rd)
T. Ishimoto, K. Hagihara, K. Hisamoto, S.-H. Sun, T. Nakano*:
Crystallographic texture control of beta-type Ti–15Mo–5Zr–3Al alloy by selective laser melting for the development of novel implants with a biocompatible low Young's modulus,
Scripta Materialia, 132 (2017), pp.34-38.

(4th)
M. Todai, T. Nagase, T. Hori, A. Matsugaki, A. Sekita, T. Nakano*;
Novel TiNbTaZrMo high-entropy alloys for metallic biomaterials,
Scripta Materialia, 129C (2017), pp.65-68.

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<Bone>

(4th)
A. Sekita, A. Matsugaki, T. Nakano*:
Disruption of collagen/apatite alignment impairs bone mechanical function in osteoblastic metastasis induced by prostate cancer,
Bone, 97 (2017), pp.83-93.

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<JALCOM>

(7th)
K. Hagihara, T. Nakano*, M. Suzuki, T. Ishimoto, S. yalatu, S.-H. Sun:
Successful additive manufacturing of MoSi2 including crystallographic texture and shape control,
Journal of Alloys and Compounds (JALCOM),696 (2017), pp.67-72.

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An article about our laboratory's research was published in the June issue of Monthly Municipal Solutions (pages 73-75).

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Our collaborative research paper has been published in Radiation Physics and Chemistry.

M. Furuta, A. Matsugaki, T. Nakano, I. Hirata, K. Kato, T. Oda, M. Sato, M. Okazaki:
Molecular level analysis of mechinical properties of PTFE sterilized by Co-60 γ-ray irradiation for clincal use,
Radiation Physics and Chemistry, 139 (2017) pp.126-131

Abstract

Recently, Co-60 gamma-ray irradiation has become markedly popular for the sterilization of biomedical materials, including expanded PTFE. However, its effect on the properties of PTFE has not been thoroughly examined. In this study, changes in the properties of PTFE before and after irradiation were analyzed physicochemically and discussed crystallographically. The tensile breaking strengths of PTFE decreased markedly on irradiation at 1 kGy, and were maintained at almost one fourth of the original value (44.3±2.5 N/mm2) ranging from 5 to 100 kGy. XPS analysis indicated that the atomic concentrations of carbon © and fluorine (F) of PTFE were not different among samples irradiated at various dosages. Raman spectra of PTFE showed a slight increase of the absorption peak intensity at 735 cm–1 in an irradiation dosage-dependent manner. X-ray diffraction showed that the crystal size of PTFE (56.7±1.0 nm) became smaller after radiation at 100 kGy (48.5±0.6 nm). These results are consistent with the above results of Raman analysis. It is suggested that the observed changes in the mechanical properties of PTFE may be due to nano-scale C–C bond scission by gamma ray irradiation, and not due to the formation of micro-scale cracks.

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Our collaborative research with the School of Dentistry, Osaka University, has been published as an open access journal in the journal "Scientific Reports" published by nature.

N. Yoneda, Y. Noiri, S. Matsui, K. Kuremoto, H. Maezono, T. Ishimoto, T. Nakano, S. Ebisu, M. Hayashi:
Development of a root canal treatment model in the rat,
Scientific Reports, 7:3315, (2017)
DOI:10.1038/s41598-017-03628-6

Abstract

Root canal treatment is performed to treat apical periodontitis, and various procedures and techniques are currently used. Although animal models have been used in the developmental research of root canal treatment, little of this research has used small animals such as rats, because of their small size. In this study, root canal treatment was performed on the rat mandibular first molar, which had four root canals, using a microscope, and the therapeutic effect was evaluated bacteriologically, radiologically and histopathologically. By performing root canal treatment, the level of bacteria in the mesial root of the treated teeth was reduced by 75% compared with the control. Additionally, the volume of the periapical lesions of the treated teeth as measured by micro-computed tomography decreased significantly 2 weeks after the root canal treatment when compared with the control. Histological evidence of healing was observed in the treatment group 8 weeks after root canal treatment. These results suggest that a root canal treatment model using rats can be used in developmental research for novel methods of root canal treatment.

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Interview about Anisotropic Custom Design and AM Center was published in the Journal of Japan Society for Precision Engineering.

Gravure & Interview Frontiers of Precision Engineering
Custom Additive Manufacturing Using the Science of Metallic Materials,
Journal of the Japan Society for Precision Engineering, Vol. 83, No. 5, pp. 387-390 (May 5, 2017)

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Our lab's article on high-entropy alloys was published in BIO INDUSTRY.

Takayoshi Nakano, Takeshi Nagase, Mitsuharu Todai:
Development of High Strength High Entropy Alloys for Biological Applications,
BIO INDUSTRY, Vol.34 [5] (2017), pp.8-20

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Our collaborative research with Prof. Takuya Matsumoto at Okayama University has been accepted and published on line in Acta Biomaterialia.

M. Okada, A. Nakai, E. Hara, T. Taguchi, T. Nakano, T. Matsumoto:
Biocompatible nanostructured solid adhesives for biological soft tissues,
Acta Biomaterialia, (2017), in press,
DOI : doi.org/10.1016/j.actbio.2017.05.014

Abstract

Over the past few years, the development of novel adhesives for biological soft tissue adhesion has gained significant interest. Such adhesives should be non-toxic and biocompatible. In this study, we synthesized a novel solid adhesive using nanostructured hydroxyapatite (HAp) and evaluated its physical adhesion properties through in vitro testing with synthetic hydrogels and mice soft tissues. The results revealed that the HAp-nanoparticle dispersions and HAp-nanoparticle-assembled nanoporous plates showed efficient adhesion to the hydrogels. Interestingly, the HAp plates showed different adhesive properties depending upon the shape of their nanoparticles. The HAp plate made up of 17 nm-sized nanoparticles showed an adhesive strength 2.2 times higher than the conventional fibrin glue for mice skin tissues.

Statement of Significance

The present study indicates a new application of inorganic biomaterials (bioceramics) as a soft tissue adhesive.Organic adhesives such as fibrin glues or cyanoacrylate derivatives have been commonly used clinically. However, their limited biocompatibility or low adhesion strength are some drawbacks that impair their clinical application. In this study, we synthesized a novel solid adhesive with biocompatible and biodegradable hydroxyapatite (HAp) nanoparticles without the aid of organic molecules, and showed an immediate and superior (i.e., 2.2 times higher) adhesion strength of mouse soft tissues compared to conventional fibrin glues. Given the importance of wet adhesion to biomedicine and biotechnology, our results suggest ways to develop new soft tissue adhesives as well as new applications of inorganic biomaterials.

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Collaborative research with Dr. Lee from our lab has been published in the Journal of Bone and Mineral Metabolism.

This study demonstrates the usefulness of biological apatite (BAp) orientation as a new index for evaluating knee osteoarthritis in knee joint cartilage.

J. ‑W. Lee, A. Kobayashi, T. Nakano*:
Crystallographic orientation of the c‑axis of biological apatite as a new index of the quality of subchondral bone in knee joint osteoarthritis,
J Bone Miner Metab, 35 [3], (2017), pp.308–314.
DOI: 10.1007/s00774-016-0754-y

Abstract
The aim of the present study was to investigate the preferred orientation of biological apatite (BAp) as a new index of the quality of subchondral bone (SB) in knee joint osteoarthritis (OA). Ten OA and five normal knee joints were obtained. Thickness, quantity and bone mineral density (BMD) of SB were analyzed at the medial condyle of the femur in dry conditions by peripheral quantitative computed tomography. In addition, the preferred crystallographic orientation of the c-axis of BAp was evaluated as bone quality parameter using a microbeam X-ray diffractometer technique. BMD and thickness of SB were significantly increased in OA specimens compared to normal knee specimens (P < 0.01), and the preferred orientation of the c-axis of BAp along the normal direction of SB surface was significantly higher in OA specimens ( P < 0.01), reflecting the change in stress of concentration in the pathological portion without cartilage. SB sclerosis in OA results in both proliferation of bone tissues and enhanced degree of preferential alignment of the c-axis of BAp. Our findings could have major implications for the diagnosis of clinical studies, including pathologic elucidation in OA.

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Dr. Nakano was granted the title of Distinguished Professor by the President of Osaka University (as of April 1, 2017).

Professor Nakano was awarded the title of Distinguished Professor of Osaka University in recognition of his achievements to date, and attended the ceremony to commemorate the occasion. He is the only one of 27 professors in Osaka University, 5 in the Graduate School of Engineering, and the only one in the Division of Materials and Manufacturing Science.
I would like to express my gratitude to the staff and students of the Nakano Institute. (Thanks to Nakano Lab staff and students.) Nakano Lab staff are honorary faculty members and students, including alumni, are honorary students (according to Prof. Nakano).

The following are the regulations.
In accordance with the "Rules for the Granting of the Title of Professor Emeritus of Osaka University" scheduled to take effect on April 1, 2017, the title of Professor Emeritus will be granted to professors of Osaka University who have received the Nobel Prize, the Order of Culture, the Fields Medal, the Distinguished Cultural Contribution Award, the Japan Academy Prize, the Duke of Edinburgh Prize of the Japan Academy Prize, the Japan Academy Prize, the Japan International Prize, the Medal with Purple Ribbon, the Kyoto Prize, the Japan Society for the Promotion of Science Prize, and other prominent awards, and who play a leading role in promoting education, research, and social contribution at Osaka University.

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An article on the mechanism of bone fragility caused by cancer metastasis, which was discovered in our laboratory, was published as the top article on the "Science and Technology and University" page of the Nikkan Kogyo Shimbun on March 21.

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Our lab's paper on the mechanism of bone microstructure disruption through interaction with cancer cells has been published as an open access journal in the journal "Scientific Reports" published by nature.

Y. Kimura, A. Matsugaki, A. Sekita, T. Nakano*:
Alteration of osteoblast arrangement via direct attack by cancer cells: New insights into bone metastasis,
Scientific Reports, 7:44824, pp.1-11
DOI: 10.1038/srep44824

Abstract
Intact bone tissue exhibits a characteristic anisotropic microstructure derived from collagen fiber
alignment and the related c-axis orientation of apatite crystals, which govern the mechanical properties
of bone tissue. In contrast, tumor-invaded bone exhibits a disorganized, less-aligned microstructure
that results in severely disrupted mechanical function. Despite its importance both in basic principle
and in therapeutic applications, the classical understanding of bone metastasis is limited to alterations
in bone mass regulated by metastatic cancer cells. In this study, we demonstrate a novel mechanism
underlying the disruption of bone tissue anisotropy in metastasized bone. We observed that direct
attack by cancer cells on osteoblasts induces the less-organized osteoblast arrangement. Importantly,
the crystallographic anisotropy of bone tissue is quantitatively determined by the level of osteoblast
arrangement. Osteoblast arrangement was significantly disrupted by physical contact with cancer
cells such as osteolytic melanoma B16F10, breast cancer MDA-MB-231, and osteoblastic prostate
cancer MDA-PCa-2b cells. The present findings demonstrate that the abnormal arrangement of
osteoblasts induced by physical contact with cancer cells facilitates the disorganized microstructure of
metastasized bone.

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Our research presentation won The Japan Institute of Metals and Materials The Metals Best Poster Award at the 160th Japan Institute of Metals and Materials.

〇Takamiki Higuchi, Takaaki Ikenishi, Koji Hagiwara, Takayoshi Nakano:
Microstructural control of C40/C11b double-layered silicide by various quaternary elements,
The 28th Japan Institute of Metals and Materials The Metals Best Poster Award, Tokyo Metropolitan University, Minami-Osawa Campus, March 16, 2017.

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Mr. Hori (M1) received a poster award at the Materials Science and Engineering Conference.

Takao Hori, Mitsuharu Todai, Takeshi Nagase, Aira Matsugaki, Takayoshi Nakano:
Thermodynamic study on phase stability and solidification structure of novel functional high-entropy alloys with bcc structure,
Materials Science and Engineering Discourse, Keizo Saji Hall, Nakanoshima Center, Osaka University, February 1, 2017.

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A paper on the successful control of <001> and <011> orientation by scan strategy dependence for low elasticity of βTi has been published in Scripta Materialia as an open access journal.

Takuya Ishimoto, Koji Hagihara, Kenta Hisamoto, Shi-Hai Sun, Takayoshi Nakano*:
Crystallographic texture control of beta-type Ti-15Mo-5Zr-3Al alloy by selective laser melting for the development of novel implants with a biocompatible low Young's modulus,
Scripta Materialia, 132 (2017), pp.34-38
DOI: 10.1016/j.scriptamat.2016.12.038

Abstract
We first successfully achieved the two types of distinct texture control in low-modulus beta-type Ti–15Mo–5Zr–3Al alloy products using selective laser melting. Bidirectional scanning with and without a rotation of 90° between the layers gave rise to different textures with preferential orientations of 〈001〉 and 〈011〉 along the building direction, respectively. Control of the growth behavior of the columnar cells in the melt pools via scanning strategies enabled the generation of such different textures. The obtained material exhibits a low Young's modulus of 68.7 ± 0.9 GPa, which potentially allows for the development of implants that can suppress stress shielding.

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A paper finding that osteogenic bone metastases from prostate cancer disrupt bone orientation and reduce bone mechanical function was published in Bone as an open access journal.

A. Sekita, A. Matsugaki, T. Nakano*:
Disruption of collagen/apatite alignment impairs bone mechanical function in osteoblastic metastasis induced by prostate cancer,
Bone, 97 (2017), pp.83-93
DOI: 10.1016/j.bone.2017.01.004

Abstract

Prostate cancer (PCa) frequently metastasizes to the bone, generally inducing osteoblastic alterations that increase bone brittleness. Although there is growing interest in the management of the physical capability of patients with bone metastasis, the mechanism underlying the impairment of bone mechanical function remains unclear. The alignment of both collagen fibrils and biological apatite (BAp) c-axis, together with bone mineral density, is one of the strongest contributors to bone mechanical function. In this study, we analyzed the bone microstructure of the mouse femurs with and without PCa cell inoculation. Histological assessment revealed that the bone-forming pattern in the PCa-bearing bone was non-directional, resulting in a spongious structure, whereas that in the control bone was unidirectional and layer-by-layer, resulting in a compact lamellar structure. The degree of preferential alignment of collagen fibrils and BAp, which was evaluated by quantitative polarized microscopy and microbeam X-ray diffraction, respectively, were significantly lower in the PCa-bearing bone than in the control bone. Material parameters including Young's modulus and toughness, measured by the three-point bending test, were simultaneously decreased in the PCa-bearing bone. Specifically, there was a significant positive correlation between the degree of BAp c-axis orientation and Young's modulus. In conclusion, the impairment of mechanical function in the PCa-bearing bone is attributable to disruption of the anisotropic microstructure of bone in multiple phases. This is the first report demonstrating that cancer bone metastasis induces disruption of the collagen/BAp alignment in long bones, thereby impairing their mechanical function.

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2016

A paper that found that melanoma, a bone-resorbing cancer, disrupts bone orientation and reduces bone mechanical function was published in the Journal of Structural Biology as an open access journal.

Aiko Sekita, Aira Matsugaki, Takuya Ishimoto, Takayoshi Nakano:
Synchronous disruption of anisotropic arrangement of the osteocyte network and collagen/apatite in melanoma bone metastasis,
Journal of Structural Biology, (2016),
DOI: 10.1016/j.jsb.2016.12.003.

Abstract
Cancer metastasis to bones increases the risk of fragility fracture by altering bone metabolism and disrupting bone structure. Osteocytes, which organize a dense network that is closely linked with the circumambient matrix, play a key role in regulation of bone microstructure and material properties. The aim of this study was to elucidate the influence of cancer metastasis on the organization of the osteocyte network and collagen/biological apatite (BAp) microstructure in the context of osteocyte/matrix coupling. Using a mouse model intracardially injected with B16F10 melanoma cells or vehicle, the geometric and metabolic changes to osteocytes were analyzed by nano-computed tomography (nano-CT) and histology, and the alignment of collagen fibrils and BAp was analyzed by birefringence measurement and microbeam-X-ray diffraction, respectively. The material properties of bones were further analyzed with nanoindentation method. These experiments revealed that the osteocyte network was markedly disorganized in cancer-bearing bone tissues. The osteocytes showed a variety of residing states in the lacunae; some lacunae were osteolytic while some were replete with immature matrix, suggesting significant disruption in osteocyte/matrix coupling. Collagen/BAp microstructure was also disorganized in cancer-bearing bones as observed by significant decreases in the preferential alignment of both collagen fibrils and BAp; the latter was further shown to be significantly correlated with Young's modulus. The present study revealed that the disruption in the arrangement of the osteocyte network and collagen/BAp microstructure and the deterioration of mechanical function occurred synchronously during cancer bone metastasis.

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An article on cell control by metal surface shape appeared in the December issue of Matelia.

Aira Matsugaki, Takayoshi Nakano:
Cell Alignment Imaging Based on Materials Engineering Methods,
Special Issue on Frontiers of Microstructure Research for Materials Development by Microscopy (10) - Advances in Microscopic Imaging Techniques and New Developments in Materials Science - (1) Various Imaging Techniques, Matelia, 55 [12], (2016), pp. 579.

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Our paper on the contribution of peculiar band structure in TiAl to mechanical properties by layer-by-layer fabrication has gained open access.

M. Todai, T. Nakano, T. Liu, H. Y. Yasuda, K. Hagihara, K. Cho, M. Ueda, M.Takayama:
Effect of building direction on the microstructure and tensile properties of Ti-48Al-2Cr-2Nb alloy additively manufactured by electron beam melting,
Additive Mannufacturing, 13C (2017), pp. 61-70
DOI: http://dx.doi.org/10.1016/j.addma.2016.11.001

Abstract
This paper clarified a novel strategy to improve the tensile properties of the Ti-48Al-2Cr-2Nb alloys fabricated by electron beam melting (EBM), via the finding of the development of unique layered microstructure composed of duplex-like fine grains layers and coarser γ grains layers. It was clarified that the mechanical properties of the alloy fabricated by EBM can be controlled by varying an angle θ between EBM-building directions and stress loading direction. At room temperature, the yield strength exhibits high values more than 550 MPa at all the loading orientations investigated (θ = 0, 45 and 90°). In addition, the elongation at θ = 45° was surprisingly larger than 2%, owing to the development of this unique layered microstructure. The anisotropy of the yield strength decreased with increasing temperature. All the examined alloys exhibited a brittle-ductile transition temperature of approximately 750 °C and the yield strength and tensile elongation at 800 °C were over 350 MPa and 40%, respectively.
By the detailed observation of the microstructure, the formation mechanism of the unique layered microstructure was found to be closely related to the repeated local heat treatment effect during the EBM process, and thus its control is further possible by the tuning-up of the process parameters. The results demonstrate that the EBM process enables not only the fabrication of TiAl products with complex shape but also the control of the tensile properties associated with the peculiar microstructure formed during the process.

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An article about the high-strength, high-entropy alloy with excellent biocompatibility developed in our laboratory was published in the Nikkan Kogyo Shimbun.

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The world's first paper on the modeling of heat-resistant MoSi₂ and the fabrication of <001]-fiber textures has gained open access.

Koji Hagihara, Takayoshi Nakano*, Masahiro Suzuki, Takuya Ishimoto, Su yalatu, Shi-Hai Sun:
Successful additive manufacturing of MoSi2 including crystallographic texture and shape control,
Journal of Alloys and Compounds (JALCOM), 696, (2017), pp.67–72
DOI: 10.1016/j.jallcom.2016.11.191

Abstract

MoSi2 is one of the promising candidates for ultrahigh-temperature structural materials. However, its product fabrication has been limited owing to its significant brittleness until now. As an approach to overcome this, we have first successfully fabricated MoSi2 samples via additive manufacturing (AM). Control of the thermal expansion coefficient of the start plate for AM is important for building a three-dimensional MoSi2 product with a low deformability. Moreover, unidirectional laser scanning is found to be significantly effective for controlling the crystallographic texture in MoSi2 with a low crystal symmetry. By the unidirectional scanning, [001] texture could be developed along the scanning direction, which possibly results in the fabrication of the MoSi2 products with better high-temperature strength.

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Dr. Nakano received the Award of Japanese Society for Biomaterials (in science field) at the Japanese Society for Biomaterials Symposium 2016.

Dr. Nakano received the Award of Japanese Society for Biomaterials(in science field) and gave the award lecture.

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The paper on dental implants considering bone orientation, which we have been working on in collaboration with Nagasaki University, is now open access.

Shinichiro Kuroshima, Takayoshi Nakano, Takuya Ishimoto, Muneteru Sasaki, Maaya Inoue, Munenori Yasutake, Takeshi Sawase:
Optimally oriented grooves on dental implants improve bone quality around implants under repetitive mechanical loading,
Acta Biomaterialia, 48, 15, 2017, pp433-444.

Abstract
The aim was to investigate the effect of groove designs on bone quality under controlled-repetitive load conditions for optimizing dental implant design. Anodized Ti-6Al-4V alloy implants with −60° and +60° grooves around the neck were placed in the proximal tibial metaphysis of rabbits. The application of a repetitive mechanical load was initiated via the implants (50 N, 3 Hz, 1800 cycles, 2 days/week) at 12 weeks after surgery for 8 weeks. Bone quality, defined as osteocyte density and degree of biological apatite (BAp) c-axis/collagen fibers, was then evaluated. Groove designs did not affect bone quality without mechanical loading; however, repetitive mechanical loading significantly increased bone-to-implant contact, bone mass, and bone mineral density (BMD). In +60° grooves, the BAp c-axis/collagen fibers preferentially aligned along the groove direction with mechanical loading. Moreover, osteocyte density was significantly higher both inside and in the adjacent region of the +60° grooves, but not −60° grooves. These results suggest that the +60° grooves successfully transmitted the load to the bone tissues surrounding implants through the grooves. An optimally oriented groove structure on the implant surface was shown to be a promising way for achieving bone tissue with appropriate bone quality. This is the first report to propose the optimal design of grooves on the necks of dental implants for improving bone quality parameters as well as BMD. The findings suggest that not only BMD, but also bone quality, could be a useful clinical parameter in implant dentistry.

Statement of Significance
Although the paradigm of bone quality has shifted from density-based assessments to structural evaluations of bone, clarifying bone quality based on structural bone evaluations remains challenging in implant dentistry. In this study, we firstly demonstrated that the optimal design of dental implant necks improved bone quality defined as osteocytes and the preferential alignment degree of biological apatite c-axis/collagen fibers using light microscopy, polarized light microscopy, and a microbeam X-ray diffractometer system, after application of controlled mechanical load. Our new findings suggest that bone quality around dental implants could become a new clinical parameter as well as bone mineral density in order to completely account for bone strength in implant dentistry.

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Our paper on high-entropy alloys has been accepted for publication in "scripta Materialia" and will be open access on November 9.

Mitsuharu Todai, Takeshi Nagase, Takao Hori, Aira Matsugaki, Aiko Sekita, Takayoshi Nakano:
Novel TiNbTaZrMo high-entropy alloys for metallic biomaterials,
Scripta Materialia, 129C, (2017), pp.65–68
DOI: 10.1016/j.scriptamat.2016.10.028

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Ms. Liu (M2) won the Best Poster Award at the 131st Japan Institute of Light Metals.

Liu Tianqi, Mitsuharu Todai, Hiroyuki Yasuda, Ken Zhao, Koji Hagiwara, Takayoshi Nakano, Ayako Ikeda, Daisuke Kondo:
Introduction of Specific Layered Microstructure by Electron Beam Additive Manufacturing and Development of High Ductility Ti-48Al-2Cr-2Nb Alloy Using the Microstructure

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An article about our laboratory's research was published in the November issue of Monthly Municipal Solutions (pages 69-71).

This article, "New findings on bone function recovery at Osaka University," was written by Takeshi Hayashi of the Nikkan Kogyo Shimbun and introduces Nakano Lab's research.

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The results of our laboratory's research on reduced bone matrix orientation under no load were published in Carcified Tissue International (CTIN).

Jun Wang, Takuya Ishimoto and Takayoshi Nakano:
Unloading-induced degradation of the anisotropic arrangement of collagen/apatite in rat femurs,
Carcified Tissue International (CTIN), (2016) in press.
DOI:10.1007/s00223-016-0200-0

Abstract
The specific orientation of collagen and biological apatite (BAp) is an anisotropic feature of bone micro-organization; it is an important determinant of bone mechanical function and performance under anisotropic stress. However, it is poorly understood how this microstructure orientation is altered when the mechanical environment changes. We hypothesized that the preferential orientation of collagen/BAp would change in response to changes in mechanical conditions, similar to the manner in which bone mass and bone shape change. In the present study, we investigated the effect of unloading (removal of anisotropic stress) on the preferential orientation of collagen/BAp using a rat sciatic neurectomy model. Bone tissue that formed under unloaded conditions showed a more disordered collagen/BAp orientation than bone tissue that formed under physiological conditions. Coincidentally, osteocytes in unloaded bone displayed spherical morphology and random alignment. To the best of our knowledge, this study is the first to demonstrate the degradation of preferential collagen/BAp orientation in response to unloading conditions. In summary, we identified alterations in bone material anisotropy as an important aspect of the bone’s response to unloading, which had previously been examined with regard to bone loss only.

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Mr. Yamazaki (M1) and our lab's presentation won The 159th Japan Institute of Metals and Materials The Metals Best Poster Award.

〇Daisuke Yamazaki, Ryosuke Kozasa, Aya Matsugaki, Takayoshi Nakano:
Construction of in vivo similar anisotropic vascular structures

Takao Hori, LIU TIANQI, Masahiro Suzuki, Kenta Hisamoto:
One-of-a-kind custom lights by metal 3D printer,
The 159th Japan Institute of Metals and Materials World Materials Day Award

〇Jisun Lee, Koji Hagiwara, Takayoshi Nakano, Michiaki Yamazaki, Yoshihito Kawamura:
Composition, temperature and strain rate dependence of plastic behavior of Mg-based LPSO phase

〇Kentaro Ishii, Koji Hagiwara, and Takayoshi Nakano.
Correlation between microstructure and dissolution behavior of Ca-Mg-Zn-based soluble multi-phase alloys

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At the 159th Annual Meeting of the Japan Institute of Metals, Dr. Todai received The 26th Japan Institute of Metals and Materials Young Researcher Award, and Dr. Ikeo (currently an assistant professor at Kobe University) received The 64th Japan Institute

○Mitsuharu Todai:
Development of Structural Materials for Biomedical Applications from the Viewpoint of Materials Physics

○Naoko Ikeo, Takuya Ishimoto, Natsumi Hiramoto, Hidetsugu Fukuda, Hiroyuki Ogisu, Yutaro Araki, Takayoshi Nakano:
Solid/Powder Clad Ti-6Al-4V Alloy with Low young’s Modulus and High Toughness fabricated by Electron Beam Melting,
Materials Transaction, Vol.56, No.5

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Mr. Inagaki won the Excellent Poster Award for Young Scientist at PRICM9.

Y. Inagaki, R. Ozasa, A. Matsugaki, T. Nakano:
Osteoblast Arrangement Controlled by Interaction with Osteoclast

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Our lab's paper on TNTZ has been published in the journal "Scientific Reports" published by nature.

Koji Hagihara, Takayoshi Nakano, Hideaki Maki, Yukichi Umakoshi, Mitsuo Niinomi:
Isotropic plasticity of β-type Ti-29Nb-13Ta-4.6Zr alloy single crystals for the development ofsingle crystalline β-Ti implants
Scientific Reports, 6, 20779, (2016)
DOI: 10.1038/srep29779

Abstract
β-type Ti-29Nb-13Ta-4.6Zr alloy is a promising novel material for biomedical applications. We have proposed a 'single crystalline β-Ti implant' as new hard tissue replacements for suppressing the stress shielding by achieving a drastic reduction in the Young's modulus. To develop this, the orientation dependence of the plastic deformation behavior of the Ti-29Nb-13Ta-4.6Zr single crystal was first clarified. Dislocation slip with a Burgers vector parallel to <111> was the predominant deformation mode in the wide loading orientation. The orientation dependence of the yield stress due to <111> dislocations was small, in contrast to other β-Ti alloys. In addition, {332} twin was found to be operative at the loading orientation around [001]. The asymmetric features of the {332} twin formation depending on the loading orientation could be roughly anticipated by their Schmid factors. However, the critical resolved shear stress for the {332} twins appeared to show orientation dependence. The simultaneous operation of <111> slip and {332} twin were found to be the origin of the good mechanical properties with excellent strength and ductility. It was clarified that the Ti-29Nb-13Ta-4.6Zr alloy single crystal shows the "plastically almost-isotropic and elastically highly-anisotropic" nature, that is desirable for the development of 'single crystalline β-Ti implant'

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Our paper on anomalous strengthening mechanism using CoCr single crystal has been published in "Scripta Materialia".

Koji Hagihara, Takayoshi Nakano, Keita Sasaki:
Anomalous strengthening behavior of Co-Cr-Mo alloy single crystals for biomedical application,
Scripta Materialia, 123 (2016), pp.149-153
DOI: 10.1016/j.scriptamat.2016.06.016

Abstract

This is the first repot on the deformation behavior of Co-Cr-Mo biomedical alloy single crystals predominantly having an fcc structure. In the single crystal, one of four ε-variants was selectively formed, and its geometry was found to drastically affect the mechanical properties. The yield stress in the [111] orientation, in which the formation of ε-phase strain-induced martensite (SIM) crosses the grown-in ε-variant, was more than six times larger than that in the [149] orientation, where SIM was formed parallel to the grown-in ε-variant. The intersection mechanism of the ε-variants is discussed via observations of the deformation microstructure.

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Mr. Sekita (D3) received the Young Researcher Award at the 36th Annual Meeting of Japanese Society For Bone Morphometry.

Aiko Sekita, Aira Matsugaki, Takayoshi Nakano:
Reduced bone orientation and its effect on bone mechanical function in a mouse model of osteogenic cancer bone metastasis

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A paper on controlling cell orientation by surface undulation through deformation was published in Crystals.

Aira Matsugaki, Takayoshi Nakano:
Control of cellular arrangement by surface topography induced by plastic deformation,
Crystals, 6(6), (2016), 73(Open access journal), on line
DOI:10.3390/cryst6060073

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Our collaborative research with Dr. Imazato of the Graduate School of Dentistry has been published in Dental Materials Journal.

Hiroyuki Miyajima, Takuya Ishimoto, Sai MA, Jihua Chen, Takayoshi Nakano and Satoshi Imazato:
In vitro assessment of a calcium-fluoroaluminosilicate glass-based desensitizer for the prevention of root surface demineralization,
Dental Materials Journal, (2016), 35(3), pp.399–407.

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Received a poster award at The Japan Institute of Light Metals.

Kentaro Ishii, Koji Hagiwara, Takayoshi Nakano:
Creation of multiphase alloys of soluble compounds in the Ca-Mg-Zn system,
Japan Institute of Light Metals Spring Meeting, Poster Award (2016)

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A paper on our collaborative research with Hagiwara Lab. was published in "Materials Letters".

Koji Hagihara, Koretaka Yuge, Takaaki Ikenishi, Haruka Araki, and Takayoshi Nakano:
Effect of additional elements on fracture toughness of (Mo0.85Nb0.15)Si2 C40/C11b lamellar-structured crystals,
Materials Letters, (2016), in press.

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A study on changes in inferior bone orientation in osteoarthritis has been published in the Journal of Bone and Mineral Metabolism (JBMM).

Jee-Wook Lee, Akio Kobayashi, Takayoshi Nakano:
Crystallographic orientation of the c-axis of biological apatite as a new index
of the quality of subchondral bone in knee joint osteoarthritis,
Bone and Mineral Metabolism (JBMM), (2016), on line.
DOI: 10.1007/s00774-016-0754-y

Abstract
The aim of the present study was to investigate the preferred orientation of biological apatite (BAp) as a new index of the quality of subchondral bone (SB) in knee joint osteoarthritis (OA). Ten OA and five normal knee joints were obtained. Thickness, quantity and bone mineral density (BMD) of SB were analyzed at the medial condyle of the femur in dry conditions by peripheral quantitative computed tomography. In addition, the preferred crystallographic orientation of the c-axis of BAp was evaluated as bone quality parameter using a microbeam X-ray diffractometer technique. BMD and thickness of SB were significantly increased in OA specimens compared to normal knee specimens (P < 0.01), and the preferred orientation of the c-axis of BAp along the normal direction of SB surface was significantly higher in OA specimens (P < 0.01), reflecting the change in stress of concentration in the pathological portion without cartilage. SB sclerosis in OA results in both proliferation of bone tissues and enhanced degree of preferential alignment of the c-axis of BAp. Our findings could have major implications for the diagnosis of clinical studies, including pathologic elucidation in OA.

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A collaborative research with Hagiwara Lab. won the Best Poster Award at the 26th Japan Institute of Metals.

〇Takaaki Ikenishi, Haruka Araki, Koji Hagiwara, Takayoshi Nakano:
Mechanical properties of Cr and Ir co-doped NbSi2/MoSi2 multiphase silicide

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Dr. Hagiwara and Dr. Inamura received The Japan Institute of Metals and Materials Meritorious Award, which is a gateway to success in the Japan Institute of Metals and Materials.

Dr. Hagiwara and Dr. Inamura received The Japan Institute of Metals and Materials Meritorious Award, which is a gateway to success in the Japan Institute of Metals and Materials.

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Our collaborative paper with Hagiwara Lab has been published in Acta Materialia.

Koji Hagihara, Takuya Okamoto, Hitoshi Izuno, Michiaki Yamasaki, Masafumi Matsushita, Takayoshi Nakano, Yoshihito Kawamura:
Plastic deformation behavior of 10H-type synchronized LPSO phase in a Mg-Zn-Y system,
Acta Materialia, 109 (2016), pp.90-102.

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Our collaborative paper with Hagiwara Lab. was published in the journal "Scripta Materialia".

Koji Hagihara, Takuya Okamoto, Michiaki Yamasaki, Yoshihito Kawamura, Takayoshi Nakano:
Electron backscatter diffraction pattern analysis of the deformation band formed in the Mg-based long-period stacking ordered phase,
Scripta Materialia, 117 (2016), pp.32-36.

Abstract
A newly proposed analysis protocol using electron backscatter diffraction pattern analysis in scanning electron microscopy (SEM-EBSD) clarified that the deformation bands formed in the Mg-based long-period stacking ordered (LPSO) phase are predominantly deformation kink bands. The kink band contains many additional boundaries within it, and the coalescence of these boundaries varies the crystal rotation angle and rotation axis at the kink band boundaries during their development. The reason for the appearance of a “beak-like” shape in deformation kink band in the LPSO phase was clarified by proposing a unique three-dimensional morphology.

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Collaborative research on two-phase layered silicide with Hagiwara Lab. was published in "Acta Materialia".

Koji Hagihara, Haruka Araki, Takaaki Ikenishi, Takayoshi Nakano:
Creep-deformation behavior of (Mo0.85Nb0.15)Si2 lamellar-structured C40/C11b two-phase crystals,
Acta Materialia, 107 (2016), pp.196-212.

Abstract
The creep-deformation behavior of (Mo0.85Nb0.15)Si2 crystals that were composed of C40 and C11b two-phases with an oriented lamellar microstructure was examined over 1200–1400 °C under compression. The creep behavior of the crystals varied greatly depending on the orientation of the loading axis with respect to the lamellar interfaces. The steady-state creep strain rate (SSCR) when the loading orientation was parallel to the lamellar interfaces (0°-orientation) was approximately 2 orders of magnitude lower than that when the loading orientation was inclined by 45° (45°-orientation). Creep tests were performed also with single crystals of C40-single-phase (Mo0.85Nb0.15)Si2, and proved that the C40-phase effectively acts as a strengthening phase in the creep behavior of the C40/C11b duplex-phase crystals. The variant-1-type C11b phase grains, which have a loading orientation parallel to [001], were also found to act as an effective strengthening component. The SSCR of the 0°-orientation was succeeded to be further decreased by controlling the lamellar microstructure via the addition of Cr. The SSCR of the 1 at.%-Cr-added lamellar-structured crystal under 300 MPa in the 0°-orientation was approximately a third of that of the non-added ternary crystal.

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An article about our laboratory was published in THE BONE.

Aira Matsugaki, Takayoshi Nakano: Regulation of cell alignment for the construction of anisotropic bone matrix

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Dr. Matsugaki's commentary article appeared in Matelia Vol. 55 "Habataku".

Aira Matsugaki:
Challenge to "Life Phenomena",
Matelia, Vol.55 [2] (2016), pp.74.

Click here for this commentary.

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A paper on our collaborative research with Osaka University School of Dentistry and The Jikei University of Tokyo has been published in Scientific Reports, a publication of "nature".

T. Shinno, T. Ishimoto, M. Saito, R. Uemura, M. Arino, K. Marumo, T. Nakano, M. Hayashi:
Comprehensive analyses of how tubule occulusion and advanced glycation end-products diminish
strength of aged dentin,
Scientific Reports, (2015), srep19849.
DOI:10.1038/srep19849

Abstract
In clinical dentistry, since fracture is a major cause of tooth loss, better understanding of mechanical properties of teeth structures is important. Dentin, the major hard tissue of teeth, has similar composition to bone. In this study, we investigated the mechanical properties of human dentin not only in terms of mineral density but also using structural and quality parameters as recently accepted in evaluating bone strength. Aged crown and root dentin (age ≥ 40) exhibited significantly lower flexural strength and toughness than young dentin (age < 40). Aged dentin, in which the dentinal tubules were occluded with calcified material, recorded the highest mineral density; but showed significantly lower flexural strength than young dentin. Dentin with strong alignment of the c-axis in hydroxyapatite exhibited high fracture strength, possibly because the aligned apatite along the collagen fibrils may reinforce the intertubular dentin. Aged dentin, showing a high advanced glycation end-products (AGEs) level in its collagen, recorded low flexural strength. We first comprehensively identified significant factors, which affected the inferior mechanical properties of aged dentin. The low mechanical strength of aged dentin is caused by the high mineral density resulting from occlusion of dentinal tubules and accumulation of AGEs in dentin collagen

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2015

Mr. Masahiro Suzuki won the Best Poster Award in the poster presentation of the Materials Development Research Meeting.

〇Masahiro Suzuki, Mitsuharu Todai, Koji Hagiwara, Takayoshi Nakano:
Effect of small amount of boron addition on layered structure and mechanical properties of NbSi2/MoSi2 multiphase silicide crystals

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Takumi Bohno won the Best Poster Award at the Kansai Branch Meeting of the Japan Institute of Light Metals.

〇Takumi Bohno, Koji Hagiwara, and Takayoshi Nakano:
Mechanism of anomalous strengthening in Ti-(Al, Ga) single crystals containing long-period regular phases

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Our lab's research results were published in the Nikkan Kogyo Shimbun.

In collaboration with Kyoto University, we have succeeded in significantly improving the toughness of MoSi2/NbSi2 by adding a small amount of boron, which is expected to be used as an ultra-high temperature resistant material for turbine blades.

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Dr. Matsugaki was awarded the Japan-Korea Society for Biomaterials Young Researcher Exchange AWARD, and furthermore was selected as the Grand Prize winner among them.

Dr. Matsugaki was awarded the Japan-Korea Society for Biomaterials Young Researcher Exchange AWARD, and furthermore was selected as the Grand Prize winner among them.

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A paper on βTi alloy was published in Acta Materialia in electronic version.

M. Tane, K. Hagihara, M. Ueda, T. Nakano, Y. Okuda:
Elastic-modulus enhancement during room-temperature aging andits suppression in metastable
TieNb-Based alloys with low body-centered cubic phase stability,
Acta Materialia, 102(2016),pp.373-384.(電子版)
DOI:10.1016/j.actamat.2015.09.030

Abstract

Changes in the elastic properties during room-temperature aging (RT aging) of metastable Ti–Nb-based alloy single crystals with low body-centered cubic (bcc)-phase stability were investigated. The elastic stiffness components of Ti–Nb–Ta–Zr alloys with different Nb concentrations were measured by resonant ultrasound spectroscopy during RT aging; the results revealed that shear moduli c′ and c44 were increased by RT aging. In the alloy with the lowest Nb concentration, i.e., with the lowest bcc phase stability, shear moduli c′ and c44 were enhanced by the largest amount. The increase rates were ∼5% for 1.1 × 107 s (127 days), whereas the bulk modulus was hardly changed by aging. In Ti–Nb–Ta–Zr–O alloys with different oxygen concentrations, shear moduli c′ and c44 of the alloy with the lowest oxygen concentration increased most significantly. Moreover, the electrical resistivity of Ti–Nb–Ta–Zr and Ti–Nb–Ta–Zr–O alloys was increased by RT aging. Importantly, the enhancements of shear moduli and electrical resistivity were suppressed by increases in the bcc-phase stability (i.e., increase in the Nb concentration) and oxygen concentration; these factors are known to suppress ω (hexagonal) phase formation. However, transmission electron microscopy (TEM) observations revealed that only a diffuse ω structure—an ω-like lattice distortion—was formed after RT aging. On the basis of alloying element effects, TEM observations, and analysis of the changes in elastic properties by using a micromechanics model, it was deduced that the enhancements of shear moduli and electrical resistivity were possibly caused by the formation of a diffuse ω structure.

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An explanatory article was published in Material Stage (Technical Information Association).

Takayoshi Nakano
Business Opportunities Created by Metal 3D Printers in the Coming Era of Tailor-Made Medicine,
Material Stage, October (2015)

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The article "On the Implementation of the SIP Innovative Design and Manufacturing Technology "Construction and Regional Demonstration of a 3D Anisotropic Customized Design and Additive Manufacturing Base"" was published in "Production and Branch Technolog

Nakano Lab. was deeply involved in the project "Construction and Regional Demonstration of 3D Anisotropic Customized Design and Additive Manufacturing Base", SIP Innovative Design and Manufacturing Technology," which was published in the autumn issue of "Production and Branch Technology" Vol. 67, No. 4.

The following is a related article.

Part 1 (University): Efforts by "University" dreaming of the creation of innovative Delight Optimization Manufacturing from Kansai
Tomoyuki Kakeshita, Toshihiro Tanaka, Takayoshi Nakano

Part 2 (Industry): Efforts of "Industry" dreaming of the creation of innovative Delight-optimized manufacturing from Kansai 
Masatoshi Teranishi, Yoshio Nakajima

Part 3 (Gov't): Gov't's Efforts to Create Innovative Delight Optimization Manufacturing from Kansai
Masaharu Furudera, Katsumi Yamaguchi, Hisashi Minami, Takayuki Nakamoto 

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Received Materia Japan Award from the Japan Institute of Metals and Materials.

A commentary (recent research) that I co-authored with Prof. Yoshimi of Tohoku University and Prof. Hosoda of Tokyo Institute of Technology won Materia Japan Award.

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Our lab's paper has been published in the journal "Iron and Steel".

Mitsuharu Todai, Koji Hagiwara, Takuya Ishimoto, Kengo Yamamoto, Takayoshi Nakano:
Development of single crystalline bone plate with low Young's odulus using beta-type Ti-15Mo-5Zr-3Al alloy ,
Iron and Steel, Vol. 101, No. 9, (2015), pp. 501-505.

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An article on bone calcification and apatite orientation was published in the journal "Osteoporosis Treatment".

Takayoshi Nakano, Takuya Ishimoto, Aira Matsugaki:
Bone Calcification, Apatite Orientation, Bone Biology with Eyes,
Osteoporosis Treatment, Vol.14, No.2 (2015), pp.97-100.

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An article about metal 3D printers was published in "Ceramics" magazine.

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Our collaborative research with Dr. Iwasaki on reduced orientation in CKD has been accepted for publication in Bone.

Y. Iwsasaki, J. J Kazama, H. Yamato, A. Matsugaki, T. Nakano, M. Fukagawa:
Altered material properties are responsible for bone fragility in rats with chronic kidney injury,
Bone, 81 (2015), pp.247-254.

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An article about the Osaka University Anisotropic Design and AM Center was published in the July issue of Monthly Municipal Solutions (pages 69-71).

This article was written by Takeshi Hayashi of the Nikkan Kogyo Shimbun and introduces the research of the Anisotropic Design and AM Center and Nakano Laboratory at Osaka University.

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A book that Dr. Nakano contributed to has been published by Springer.

Takayoshi Nakano:
Bone Tissue and Biomaterial Design Based on the Anisotropic Microstructure,
Advances in Metallic Biomaterials~Tissues, Materials and Biological Reactions~
Springer Series in Biomaterials Science and Engineering, Volume 3, (2015) pp.3-30
ISBN: 978-3-662-46835-7 (Print) 978-3-662-46836-4 (Online)

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Dr. Nakano received the Best Review Award and gave the award lecture at the Smart Processing Society for Materials, Environment & Energy.

Takayoshi Nakano: Development of metal-based biofunctional materials using additive manufacturing technology (3D printing)

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A paper on our collaborative research with Institute for Frontier Medical Sciences, Kyoto University was published in Biomaterials.

Masaya Yamamoto, Akishige Hokugo, Yoshitake Takahashi, Takayoshi Nakano, Masahiro Hiraoka,Yasuhiko Tabata:
Combination of BMP-2-releasing gelatin/β-TCP sponges with autologous bone marrow for bone regeneration of X-ray-irradiated rabbit ulnar defects,
Biomaterials, vol.56 (2015), pp.18-25.
DOI: 10.1016/j.biomaterials.2015.03.057.

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News about Nakano Laboratory was featured in "Welding Technology".

Nakano Lab. was featured in "Welding Technology" Vol.63 No.5, "Successful fabrication of 3D metal objects with excellent energy absorption for developing anisotropic manufacturing market.

This achievement was featured in the "SIP (Strategic Innovation Program)" led by the Cabinet Office and commissioned by NEDO.
This achievement was made through the "Construction and regional demonstration of a 3D anisotropic customized design and additive manufacturing base" of the "Innovative Design and Manufacturing Technology (Sasaki PD)" program led by the Cabinet Office and commissioned by NEDO.
This achievement is based on the "Construction and regional demonstration of a three-dimensional anisotropic customized design and additive manufacturing base" of the "SIP (Strategic Innovation Program) Innovative Design and Production Technology (Sasaki PD)" commissioned by NEDO.

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Our collaborative research with Hagiwara Lab. won The Japan Institute of Metals and Materials The Metals Best Poster Award.

Haruka Araki, Takaaki Ikenishi, Koji Hagiwara and Takayoshi Nakano:
Change in high temperature creep behavior of NbSi2/MoSi2 duplex silicide by addition of quaternary elements

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Mr. Fujitani received The 46th Japan Institute of Metals and Materials Technical Skill Award.

Mr. Fujitani received The 46th Japan Institute of Metals and Materials Technical Skill Award.

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Ms. Aimi Murakami won the poster award in the poster presentation at the Materials Science and Engineering Conference.

Aimi Murakami, Takuya Ishimoto, and Takayoshi Nakano:
Anisotropic microstructure construction of bone that is functionally hostile to artificial stress distribution.

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Mr. Noboru Inoue won the Excellent Best Poster Award and Ms. Yui Tanaka won the Best Poster Award in the poster presentation at the Materials Development Research Meeting.

Noboru Inoue, Ai Serizawa, Takayuki Nakamoto, Takahiro Kimura, Takuya Ishimoto, and Takayoshi Nakano:
Design of Anisotropic Co-Cr-Mo Alloy Structures by Additive Manufacturing Method for Development of Novel Bone Implants

Yui Tanaka, Takuya Ishimoto, Mitsuharu Todai, Takayoshi Nakano, Yohei Kawanishi, Koji Sakai, Tsuyoshi Murase, Hideki Yoshikawa:
Development of a Low Specific Elasticity Implant for Stress Shielding Suppression and Its Effect on Bone Orientation

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2014

Frontiers of Biomaterials Research (edited by Naoyuki Narushima and Takayoshi Nakano, published by the Japan Institute of Metals and Materials) has been published.

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SIP, in which our laboratory is deeply involved, was introduced on the front page and the 6th page of Nikkan Kogyo Shimbun.

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Dr. Ishimoto gave a lecture at the Korean Society for Biomaterials and received the "Young Scientist Award" from The Japanese-Korean Society for Biomaterials.

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Nakano Lab's 3D printer was featured in the Nikkan Kogyo Shimbun's "Exploring Advanced Research" section.

A special feature in the Nikkan Kogyo Shimbun's "Exploratory Advanced Research" section is titled "Bone Mimetic Implants - High Functionality with 3D Printing".
The article introduces the development of artificial joints by metal laminated molding method focusing on the anisotropy of apatite/collagen at Nakano Lab.
The article introduces the development of artificial joints by metal laminated modeling method focusing on the anisotropy of apatite/collagen.

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Our paper has been published electronically in "Biomaterials".

A. Matsugaki, G. Aramoto, T. Ninomiya, H. Sawada, S. Hata, T. Nakano:
Abnormal arrangement of a collagen/apatite extracellular matrix orthogonal to osteoblast alignment is constructed by a nanoscale periodic surface structure,
Biomaterials (2015), pp. 134-143.

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We are pleased to announce that our paper has been selected for the "Best Paper Award of the Japanese Society for Clinical Biomechanics".

Aira Matsugaki, Natsuko Fujiwara, and Takayoshi Nakano:
Regulation of bone matrix structure by long-term mechanical stress response of osteoblasts.
Japanese Society for Clinical Biomechanics, 35 (2014). pp7-13.

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The article "Considering manufacturing with 3D printers", supervised and written by Dr. Nakano, was published in Functional Materials.

Dr. Nakano supervised and contributed to the "Special Feature" "Consideration of Manufacturing with 3D Printers" and"Special Feature" "Manufacturing with 3D Printers" - Focusing on the importance of material and structural parameters - was published in Functional Materials (September 2014, Vol. 34, No. 9) has been published.

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Our paper on Electron Beam Additive Manufacturing has been published in the electronic edition of Met. Trans. A.

N. Ikeo, T. Ishimoto, A. Serizawa, T. Nakano:
Control of Mechanical Properties of Three-Dimensional Ti-6Al-4V Products Fabricated by Electron Beam Melting with Unidirectional Elongated Pore,
Metallurgical and Materials Transactions A, 45, 10, (2014) pp.4293-4301.

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Dr. Nakano, Dr. Ishimoto, and Dr. Matsugaki gave a talk at the Japanese Society For Bone Morphometry @ Sapporo, and Dr. Matsugaki received the "Young Researcher Award".

Takayoshi Nakano, Takuya Ishimoto:
Bone orientation imaging as a bone quality index (Symposium Lecture)
Takuya Ishimoto, Shun Wang, Takayoshi Nakano: Bone orientation of rat ulna by artificial loading.
Bone orientation of rat ulna by artificial loading
Aira Matsugaki, Natsuko Fujiwara, Takayoshi Nakano.
Mechanical response of osteoblasts induces the formation of oriented bone matrix

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A collaborative paper with Dr. Paidar from Czech Republic has been published in the electronic version of Journal of Alloys and Compounds.

V. Paidar, T. Nakano:
Misfit analysis in lamellar microstructure in NbSi2/MoSi2 duplex crystals,
Journal of Alloys and Compounds, Volume 607, 15 September (2014), pp.48-49

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Dr. Nakano's article "Medical applications of 3D printers" was published in Nihon Igyo Shimpo.

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Dr. Nakano received The Japan Society of Mechanical Engineers Award.

Dr. Nakano received The Japan Society of Mechanical Engineers Award.

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The results of the collaborative research with Atlee Corporation have been published in the electronic version of J Biomed Mater Res Part A.

We have succeeded in controlling the anisotropy of the microstructure of the bone matrix, including the arrangement of osteoblasts and even calcified tissue, by using collagen sheets with a controlled degree of alignment of oriented collagen for the soundness of the bone microstructure. This achievement enables the reconstruction of bone-like microstructure from the early stage of bone regeneration and opens the way to the early regeneration of mechanical function.

Aira Matsugaki, Yoshihiro Isobe, Taro Saku, Takayoshi Nakano:
Quantitative regulation of bone-mimetic, oriented collagen/apatite matrix structure depends on the degree of
osteoblast alignment on oriented collagen substrates,
J Biomed Mater Res Part A, Vol.103 (2) (2015), pp. 489–499. (2014) on-line
DOI:10.1002/jbm.a.35189.

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Bone Metabolism: Making, Breaking, and Changing Bone Metabolism - Its Mechanism and Latest Treatment", which Dr. Matsugaki and Dr. Nakano contributed to, has been published.

Bone Metabolism: Making, Breaking, and Changing - Its Mechanisms and Latest Treatments" edited by Dr. Sakae Tanaka (University of Tokyo Medical School), which Dr. Matsugaki and Dr. Nakano contributed to, has been published by Yodo-sha.

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The results of the collaborative research between our lab and Hagiwara Lab were published in the Nikkan Kogyo Shimbun.

We have succeeded in improving the fracture toughness of two-phase layered silicide, which is expected to be an ultra-high temperature heat-resistant material discovered in our laboratory.

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Lecturer Takuya Ishimoto was introduced in the Nikkan Kogyo Shimbun's "Pioneering Researchers".

Lecturer Takuya Ishimoto was introduced in the Nikkan Kogyo Shimbun, "Pioneering Researchers (24) Deepening "Anisotropy" to Create Biomaterials".
In the article, he talks about his research activities and aspirations.

20140402 日刊工業新聞 拓く研究人-desize.bmp

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Dr. Takuya Ishimoto has been promoted to Lecturer.

As of April 1, Dr. Takuya Ishimoto has been promoted to the position of Lecturer in Nakano Laboratory.

He will work more energetically on research and education, produce meaningful research results, and above all, contribute to the creation of a laboratory where the students can be proud of having come to Nakano Laboratory. (According to him)

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A collaborative research with the Bhabha Atomic Research Center in India and a group from Kyushu University was published in the electronic version of Philosophical Magazine.

P.S. Ghosh, A. Arya, U.D. Kulkarni, G.K. Dey, S. Hata, T. Nakano, K. Hagihara & H. Nakashima:
Ab-initio study of long-period superstructures and anti-phase boundaries in Al-rich γ-TiAl (L10)-based alloys,
Philosohical Magazine, (2014),pp. 1202-1218.
DOI: 10.1080/14786435.2014.885135

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Mr. Ryosuke Ozasa won The Japan Institute of Metals and Materials The Metals Best Poster Award at the 154th Annual Meeting.

Ryosuke Ozasa, Aira Matsugaki, and Takayoshi Nakano:
Mechanism of regulation of bone orientation by osteoclast-osteoblast interaction

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3D Organization of Cells - Its Cutting-Edge Technology and Material Technology", which Dr. Nakano contributed to, has been published.

3D Organization of Cells - Its Advanced Technology and Material Technology for Application and Development to Regenerative Medicine and its Supporting Fields (Cell Research and Drug Discovery Research)", which Dr. Nakano contributed to, has been published by Medical Do Co.
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Dr. Nakano and Dr. Matsugaki's comments on STAP cells were published in Nikkan Kogyo Shimbun.

Dr. Nakano and Dr. Matsugaki's comments on STAP cells were published in Nikkan Kogyo Shimbun.

 

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2013

In The Japan Institute of Metals and Materials, The Iron and Steel Institute of Japan, Kansai Branch, Materials Development Research Group, Mrs.Hiramoto received the Best Presentation Award at the 4th meeting of the research group and poster presentation

〇Natsumi Hiramoto, Ai Serizawa, Takayoshi Nakano:  
Development of osteomechanically compatible Ti-based non-equilibrium hybrid alloys by the multilayer fabrication/SPS composite method.

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Our laboratory's research description was published in Biomaterials magazine.

Ai Serizawa, Takayoshi Nakano:
Special Issue on Revolution in Molding of Medical Devices, Optical Additive Manufacturing and CAD/CAM "Molding and Development of Bone Substitute Materials by Electron Beam Additive Manufacturing",
Biomaterials, 31 [4] (2013), pp. 228-237.

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Heartwarming articles about Dr. Nakano in the Nikkan Kogyo Shimbun (April 23 and October 30) (Column)

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The Nikkan Kogyo Shimbun published an article about our laboratory's composite of bone matrix and titanium alloy (S-Inove achievement).

The Nikkan Kogyo Shimbun published an article about our laboratory's composite of bone matrix and titanium alloy (S-Inove achievement).

2013-10-23日刊工業新聞(骨質とチタン合金複合化)Sイノベ成果.jpg

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Anti-Aging Series 3: The Forefront of Bone Research - From Metabolism and Disease Mechanisms to Regenerative Medicine, Drug Discovery, Rehabilitation Devices, and Functional Foods" has been published.

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The Sanyo Shimbun took a close-up look at Eiji Fukuda, who completed the doctoral course at our laboratory at the end of September.

The Sanyo Shimbun took a close-up look at Eiji Fukuda, who completed the doctoral course at our laboratory at the end of September.
Click here for this article.

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Dr. Fukuda and Dr. Matsugaki received their doctoral degrees.

The degree conferral ceremony was held on September 25. From Nakano laboratory, Dr. Eiji Fukuda and Dr. Aira Matsugaki received their doctoral degrees.

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An article about our laboratory was published in the Nikkan Kogyo Shimbun on September 18.

An article about our laboratory was published in the Nikkan Kogyo Shimbun on September 18.

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Four posters from our laboratory received 21st The Japan Institute of Metals and Materials.

〇Taiki Nishikawa, Aira Matsugaki, Mitsuharu Todai, Takayoshi Nakano:

Control of Osteoblast Arrangement by Using Substrate Surface Morphology

 

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〇Tomoki Tanaka, Ai Serizawa, Koji Hagiwara, and Takayoshi Nakano:

Wear properties of Ti-6Al-4V alloy single crystal and its controlling factors

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〇Hiroyuki Ogisu, Takuya Ishimoto, Akira Matsugaki, Takayoshi Nakano:

Anisotropic bone regeneration behavior by implantation of oriented materials in bone defects and its influencing factors

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〇Yutaro Araki, Takuya Ishimoto, Takayoshi Nakano, Riki Nishida, Eiji Taguchi, Hidehiro Yasuda:

Quantitative Analysis of Bone Bioapatite Nano-Oriented Structure and Its Contribution to Mechanical Function Anisotropy

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Our paper was awarded the 61st The Japan Institute of Metals and Materials The Best Paper Award.

Y. Noyama, T. Miura, T. Ishimoto, T. Itaya, M. Niinomi and T. Nakano:
Bone loss and reduced bone quality of the human femur after total hip arthroplasty under stress-shielding effects by titanium-based implant.

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We received the 36th The Japan Institute of Metals and Materials Technical Development Award at the 2013 Fall Meeting.

Eiji Fukuda, Hiroyuki Takahashi, Seiji Nakagawa, Yoshio Nakajima, Takayoshi Nakano:
Development of a bone-like functionalized joint prosthesis by electron beam additive manufacturing

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A conversation with the President appeared in the September issue of the Osaka University NewsLetter.

Click here for page1.
Click here for page2.

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A collaborative research results with Prof. Imai of Keio University and Prof. Otsuki of Nagoya University were published in Journal of Asian Ceramic Societies.

W. Wang, Y. Oaki, C. Ohtsuki, T. Nakano, H. Imai:
Formation of c-axis-oriented columnar structures through controlled epitaxial growth of hydroxyapatite,
Journal of Asian Ceramic Societies, 1 (2013), pp.143-148.

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The September 2013 issue of the magazine "Monthly Functional Materials", for which Dr. Nakano edited a special feature, is now available.

[Special Feature] The Forefront of Technology for Biomaterials with High Functionality
Modern Trend of Functionalization of Biomaterials: Anisotropic Control of Tissue and Biomaterials
Modern Trend of Functionalization of Biomaterials
Based on Anisotropic Control of Biological Tissues and Materials

・High Functionality and Anisotropy of Metal Biomaterials
・Morphological Control of Calcium Phosphate Materials for Artificial Bone
・Functionalization of Metal Surfaces by Controlling Polymer Arrangement
・Photoreactive MPC polymers for surface functionalization of materials
・Functionalization of metallic biomaterial surfaces by ceramic coating
・Functionalization of biomaterials based on bioanisotropy
・Polymer biomaterials that mimic the main chain structure of nucleic acids
・Design of materials and structures using laminated modeling to enhance the functionality of artificial joints

Material Report-R&D-
・Development of organic phase-change optical recording materials
◇Columns: Masters Cafe - Techno Comments by Former Engineers and Researchers
・Research and Development

□■□From the Editor

The quality of medical care is increasing due to the changing lifestyles of modern people and the advent of a super-aging society, and there is an urgent need to enhance the functionality and performance of biomaterials to improve the quality of life of patients. In this issue of "Functional Materials", we focus on "biomaterials" and feature various technologies aiming at high functionality.

Biomaterials are artificially created materials that supplement or assist the functions of living organisms, and it is important to design materials that mimic living organisms and "behave as if they were living tissues" in order for artificial materials to function properly in living organisms. In order to achieve this, it is important to design materials that mimic living organisms and "behave as if they were living tissue. This is where the control of anisotropy comes into focus.
Biological tissues have "orientation dependence" in response to forces from various directions during their evolution under gravitational environment, and they have low symmetry and exhibit only the necessary functions in the necessary directions.
In this special issue, we consider this anisotropy control as an important point of view, and collected the latest research trends in the enhancement of various materials.

The word "behave", which I heard from the supervisor of this project when we were discussing the project, left an impression on me, as if it was a determination or intention for artificial materials to be close to the living body. Please take a look at this issue to see the progress in materials technology that directly affects our lives.
(Editor: Yanase)

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The article was published in the Nikkan Kogyo Shimbun on August 26.

Click here for this PDF.

 

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We are pleased to announce that we have been selected to receive various awards from The Japan Institute of Metals and Materials in 2013.

We are pleased to announce that the following paper from our laboratory has been selected for the 61st The Japan Institute of Metals and Materials The Best Paper Award.

Y. Noyama, T. Miura, T. Ishimoto, T. Itaya, M. Niinomi and T. Nakano:
Bone loss and reduced bone quality of the human femur after total hip arthroplasty under stress-shielding effects by titanium-based implant.

In addition, we have received The Japan Institute of Metals and Materials Technical Development Award.
Dr. Fukuda of our laboratory will give the following award lecture.

Eiji Fukuda, Hiroyuki Takahashi, Seiji Nakagawa, Yoshio Nakajima, Takayoshi Nakano:
Development of bone-like functionalized joint prosthesis by electron beam additive manufacturing method,
Matelia, 52 [2], (2013) pp. 74-76.

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The Sanyo Shimbun published an article about our laboratory.

An article was published in the Sanyo Shimbun on August 10, 2013, on the local economy page (page 6) with the headline, "Explanatory book on artificial joints written by Nakashima Medical employees and doctors.
The article is about the book "Towards Future Artificial Joints" published recently by Nihon Igakukan, in which our laboratory also contributed to writing.

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Dr. Nakano received the Chancellor's Award in the "Research Category" again last year.

Dr. Nakano received the Chancellor's Award in the "Research Category" again last year.

 

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Dr. Mitsuharu Todai received the President's Award.

Dr. Mitsuharu Todai received the President's Award.

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The article was published in "THE BONE" magazine.

Aira Matsugaki, Takuya Ishimoto, and Takayoshi Nakano:
Orientation and orientation control of bone matrix microstructure,
THE BONE, 27 [2] (2013), pp. 109-114.

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Assistant Professor Takuya Ishimoto received the 2012 Research Encouragement Award from the Committee on Biological and Medical Materials of the Society of Materials Science, Japan.

Assistant Professor Takuya Ishimoto was awarded the Research Encouragement Prize for "Elucidation of Biological Bone Functionality and Creation of Orientation-Controlled Materials Based on Materials Engineering," and gave a commemorative lecture.

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Our paper was published in the electronic edition of Acta Materialia.

K. Hagihara, T. Tanaka, H. Izuno, Y. Umakoshi, and T. Nakano:
Non-basal slips in Ni3 and Ni3 single crystals with various long-period stacking ordered structures,
Acta Materialia (2013), doi: org/10.1016/j.actamat.2013.04.008.
Click here for this paper.

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A collaborate research paper on mandibular bone orientation with Tokyo Dental University was published.

T. Matsumoto, S. Matsunaga, T.Morioka, T. Nakano, M, Yoshinar and Y. Yajima:
Relationship between Preferential Alignment of Biological Apatite and Young’s Modulus at First Molar in Human Mandible Cortical Bone,
Journal of Hard Tissue Biology, 222 (2013), pp.163-170

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The Nikkan Kogyo Shimbun published an article on S-Innovation, in which our laboratory participates.

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A paper will be published in the Journal of the Japan Institute of Metals and Materials.

Pan Wang, Mitsuharu Todai, Takayoshi Nakano:
Instability of β-phase in single crystals of Ti-Nb binary alloys for biological applications and its effect on fundamental properties,
77, [7], (2013) in press.

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Our lab's paper was published in Acta Biomaterialia.

A. Matsugaki, N. Fujiwara and T. Nakano:
Continuous cyclic stretch induces osteoblast alignment and formation of
anisotropic collagen fiber matrix,
Acta Biomaterialia, (2013), DOI: 10.1016/j.actbio.2013.03.015.

Click here for this paper.

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We received the 63rd The Japan Institute of Metals and Materials Metallography Award (Optical Microscopy Section "Excellence Award") at the Japan Institute of Metals.

Mrs. Matsugaki received the certificate as a representative.

Aira Matsugaki, Takuya Ishimoto, Natsuko Fujiwara, Taisei Taguchi, Takayoshi Nakano:
Control of cell arrangement based on Materials Scientific techniques for providing crystallographic anisotropy of bone tissue.

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Mr. Horiuchi of Hagiwara Lab. won the 20th The Japan Institute of Metals and Materials The Best Paper Award for our collaborate research.

Kazuhiro Horiuchi, Koji Hagiwara, Aira Matsugaki, Takayoshi Nakano:
Creation of biomeric affinity (K,Na)NbO3/HAp complex phase voltage material, and organization and control

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An article related to our laboratory was published in the Nikkan Kogyo Shimbun (front page).

Click here for the electronic version of the article.

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Our paper on (Al,Ga)-Ti-based long-period regular phases was published in the electronic version of Philosophical.

Takayoshi Nakano, Koji Hagihara , Satoshi Hata , Hajime, Shigyo, Hideharu Nakashima, Yukichi Umakoshi, Ashok Aryad and Ulhas D. Kulkarni:
Long-period ordered superstructures that appear in an (Al,Ga)-rich (Al,Ga)Ti system, Philosophical Magazne, Doi.org/10.1080/14786435.2012.699691, (2013) in press.

Click here for this paper.

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The February issue of Matelia featured a commentary by Dr. Fukuda and others from our laboratory's Doctoral Course for Working Adults.

Eiji Fukuda, Hiroyuki Takahashi, Seiji Nakagawa, Yoshio Nakajima, Takayoshi Nakano:
Development of bone-like functionalized joint prosthesis by electron beam additive manufacturing method (New Technology and New Product), Matelia, 52 [2], (2013) 74-76.

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Mr. Fukunaga in our lab won the Best Poster Award. 

The Japan Institute of Metals and Materials and The Iron and Steel Institute of Japan, Kansai Branch, held the third lecture and poster presentation in 2012.
Mr. Fukunaga in our laboratory won the Best Poster Award. 

Keisuke Fukunaga, Mitsuharu Todai, Takayoshi Nakano, Naoyuki Nomura (Tohoku Univ.), Takao Hanawa (Tokyo Med. & Dent. Univ.):
ω-phase transformation and modulation structure in Zr-Nb alloys for biological applications.

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Nakano Lab's topics have been introduced in the JSPS's KAKENHI NEWS.

Nakano Lab's topics have been introduced in the JSPS's KAKENHI NEWS.
Click here for more details.

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A report on the public lecture by researchers of the Next Generation Research and Development Support Program was published in "Matelia".

A report on the public lecture held on October 27th by researchers of the Next Generation R&D Support Program was published in the January 2013 issue of Matelia.

Y. Mitarai, K. Yoshimi, H. Hosoda, and T. Nakano:
Public Lecture for Dialogue with the Public: "Materials Research Frontier for Green Life Innovation",
Matelia, Vol. 52, January 2013, pp. 32-35.

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The Nikkan Kogyo Shimbun published an article about the research results of our Graduate School of Medicine and Nakashima Medical Co.

The Nikkan Kogyo Shimbun published an article about the research results of our Graduate School of Medicine and Nakashima Medical Co.

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The photo of the collaborate research paper with Hagiwara Lab. was used for the cover of the January 2013 issue of Materials Transactions (Vol. 54 [1]).

K. Hagihara, Y. Sugino, Y. Fukusumi, Y. Umakoshi and T. Nakano:
Plastic Deformation Behavior of Mg12ZnY LPSO-Phase with 14H-Typed Structure, Materials Transactions, 52 (2011), pp.1096-1103.

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2012

Our lab's paper will be on the cover of Bone magazine in February 2013.

Y. Noyama, T. Nakano, T. Ishimoto, T. Sakai and H. Yoshikawa:
Design and optimization of the oriented groove on the hip implant surface to promote bone microstructure integrity,
Bone, 52 (2013), pp.659–667.
DOI information: 10.1016/j.bone.2012.11.005.

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Progress in Advanced Structural and Functional Materials Design" has been published.

T. Nakano, T. Ishimoto, N. Ikeo and A. Matsugaki:
Advanced Analysis and Control of Bone Microstructure Based on a Materials Scientific Study Including Microbeam X-ray Diffraction,
Progress in Advanced Structural and Functional Materials Design, Springer, (2012), pp.155-167,
DOI: 10.1007/978-4-431-54064-9.

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It was published in the electronic version of the Journal of Bone and Mineral Research (JBMR).

T. Ishimoto, T. Nakano. Y. Umakoshi, M. Yamamoto, Y. Tabata:
Degree of biological apatite c-axis orientation rather than bone mineral density controls mechanical function in bone regenerated using rBMP-2,
Journal of Bone and Mineral Research (JBMR), (2013), 285, 1170-1179.
doi: 10.1002/jbmr.1825.

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A paper from our lab has been published in the electronic version of Bone magazine.

Y. Noyama, T. Nakano, T. Ishimoto, T. Sakai and H. Yoshikawa:
Design and optimization of the oriented groove on the hip implant surface to promote bone microstructure integrity,
Bone, (2012).
DOI information: 10.1016/j.bone.2012.11.005.

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A collaborative research paper with Dr. Tane was published in the electronic version of Acta Materialia.

M. Tane, T. Nakano, S. Kuramoto, M. Niinomi, N. Takesue, and H. Nakajima:
ω Transformation in Cold Worked Ti-Nb-Ta-Zr-O Alloys with Low Body-centered Cubic Phase Stability and Its Correlation with Their Elastic Properties,
Acta Materialia, (2012)
DOI: org/10.1016/j.actamat.2012.09.041.

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We participated in Bioceramics24.

We participated in the 24th Symposium and Annual Meeting of the International Society for Ceramics in Medicine (Bioceramics 24), which was held in Fukuoka from October 21-24.

Doctor course students, Mrs. Suetoshi (D3) and Fukuda (D2), gave poster presentations.

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The paper has been accepted for "Dental Materials Journal".

A paper about our findings of the collaborative research with Professor Matsuura (Division of Health Sciences, Osaka University) has been accepted for "Dental Materials Journal".

 

Y. Hamada, W. Fujitani , N. Kawaguchi, K. Daito, T. Niido, A. Uchinaka, S. Mori, Y. Kojima, M. Manabe, K. Nishida, K. Arita, T. Nakano and N. Matsuura: The preparation of PLLA/calcium phosphate hybrid composite and its evaluation of biocompatibility, Dental Materials Journal, (2012) in press.

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Professor Nakano participates in PM2012.

We participated in the 2012 Powder Metallurgy World Congress and Exhibition (PM2012), which was held at PACIFICO YOKOHAMA Conference Center from October 14-18.

Professor Nakano gave an oral presentation.

 

N. Ikeo, T. Matsumi and T. Nakano
"Mechanical properties of porous Ti alloy products fabricated by electron beam melting method"

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Professor Nakano participates in The 60th General Session of JSDMD

We participated in The 60th General Session of the Japanese Society for Dental Materials and Devices (JSDMD), which was held in Fukuoka from October 13-14.

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Professor Nakano was awarded the Best Presentation Award.

T. Nakano, W. Fujitani and T. Aramaki
「下顎骨におけるアパタイト配向性の支配因子の解明」

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An announcement for a symposium appeared in the newspaper.

We will organize a symposium on October 27th, which are open to public. Professor Nakano will give a lecture.

 

Brochure↓

http://www.lserp.osaka-u.ac.jp/files/nakano_flyer_20121027.pdf

 

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The paper has been accepted for "Medical and Biological Engineering and Computing"

A paper about our findings of the collaborative research with Professor Takano (Keio University) has been accepted for "Medical and Biological Engineering and Computing ".

 

K. S. Basaruddin, N.Takano, Y. Yoshiwara and T. Nakano:
Morphology analysis of vertebral trabecular bone under dynamic loading based on multi-scale theory,
Medical and Biological Engineering and Computing (2012) 50, pp.1091–1103,

DOI: 10.1007/s11517-012-0951-3

 

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Article about our laboratory appeared in the newspaper.

Our findings of the collaborative research with Associate Professor Tane (The Institute of Scientific and Industrial Research (ISIR), Osaka University), Professor Niinomi (Institute for Materials Research, Tohoku University) and Toyota Central R&D Labs. were appeared in Nikkan Kogyo Newspaper on October 2nd.

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Professor Nakano organized Korea-Japan Joint Symposium on Biomaterials.

Professor Nakano organized Korea-Japan Joint Symposium on Biomaterials, which was held at Osaka University from September 24-26.

 

The lecturers were Prof. Hyun-Kwang Seok (KIST), Prof. Seok-Jo Yang (Chungnam National University), Prof. Pil-Ryung Cha (Kookmin University), Prof. Takayuki Narushima (Tohoku University), Prof. Shinji Fujimoto (Osaka University), Takayoshi Nakano (Osaka University).

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members of our laboratory participated in 2012 Annual Autumn Meeting of The Japan Institute of Metals.

We participated in 2012 Annual Autumn Meeting of The Japan Institute of Metals., which was held at Ehime University in Matsuyama from September 17-19. A lot of members and alumni were awarded the prizes below.

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An article about our laboratory appeared in KAGAKUDOJIN journal.

An article about our laboratory appeared in the October issue of KAGAKUDOJIN journal.

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A collaborative research paper between our lab and Prof. Takuya Matsumoto of Okayama University has been published in the electronic version of Integrative Biology.

J. Sasaki, T. Matsumoto, H. Egusa, M. Matsusaki, A Nishiguchi, T. Nakano, M. Akashi, S. Imazatoa and H. Yatani:
In vitro reproduction of endochondral ossification using a 3D mesenchymal stem cell construct,
Integrative Biology, (2012).
DOI: 10.1039/c2ib20027a.

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The results of our collaborative research with Professor Satoru Toyosawa of the Graduate School of Dentistry have been published in the electronic version of the Journal of Bone and Mineral Metabolism (JBMM).

R. Kagawa, M. Kishino, S. Sato, K. Ishida, Y. Ogawa, K. Ikebe, K. Oya, T. Ishimoto, T. Nakano, Y. Maeda, T. Komori and S. Toyosawa:
Chronological histological changes during bone regeneration on a non-crosslinked atelocollagen matrix, Journal of Bone and Mineral Metabolism, (2012).
DOI 10.1007/s00774-012-0376-y.

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Our paper was published in the electronic version of "Biomaterials".

A. Matsugaki, G, Aramoto, T. Nakano:
The alignment of MC3T3-E1 osteoblasts on steps of slip traces introduced by dislocation motion,
Biomaterials (2012).
DOI: 10.1016/j.biomaterials.2012.06.022.

Click here for this paper.

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Our paper was published in the electronic version of "Bone" magazine.

T. Nakano, K. Kaibara, T. Ishimoto, Y. Tabata, Y. Umakoshi:
Biological apatite (BAp) crystallographic orientation and texture as a new index for assessing the microstructure and function of bone regenerated by tissue engineering,
Bone (2012).
doi:10.1016/j.bone.2012.07.003

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Our lab's paper has been published in the Journal of the Japan Institute of Metals.

Yoshihiro Noyama, Takuya Miura, Takuya Ishimoto, Naoko Ikeo, Mitsuo Niinomi, and Takayoshi Nakano:
Bone Loss and Bone Quality Degradation in Human Femur Caused by Stress Shielding from Titanium-Based Implants after Hip Joint Replacement,
Journal of the Japan Institute of Metals, 76 [7] (2012), 49 (2012), pp. 468-473.

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Received the Award for Excellence in Presentation at the Annual Meeting of The Japanese Society for Dental Materials and Devices.

The following presentation at the 59th Annual Meeting of The Japanese Society for Dental Materials and Devices was selected for the Best Presentation Award at the Annual Meeting of The Japanese Society for Dental Materials and Devices.

Takayoshi Nakano, Wataru Fujitani, Chieko Aramaki:
Elucidation of the Controlling Factors of Apatite Orientation in the Mandible

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Our paper was published in the electronic version of Philosophical Magagine.

Our paper has been published in the electronic version of Philosophical Magagine.
The paper is about the development of long-period regular phases in Al-Ga-Ti.

T. Nakano, K. Hagihara, S. Hata, H. Shigyo, H. Nakashima, Y. Umakoshi, A. Arya and U. D. Kulkarni:
Long-period ordered superstructures that appear in an (Al,Ga)-rich (Al,Ga)Ti system,
Philosophical Magazine, (2012), DOI:10.1080/14786435.2012. 699691.

Click here for this paper.

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The paper co-authored with Prof. Takano of Keio University, published in the Journal of Biomechanical Science and Engineering (JBSE), was selected for the 2011 JBSE Papers of the Year Award and the Graphics of the Year Award.

The paper co-authored with Prof. Takano of Keio University, published in the Journal of Biomechanical Science and Engineering (JBSE), was selected for the 2011 JBSE Papers of the Year Award and the Graphics of the Year Award.

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The commentary, "Recent Research," written by three researchers selected for the Funding Program for World-Leading and Next-Generation R&D, was published in the April issue of the Journal of the Japan Institute of Metals.

Kyosuke Yoshimi, Hideki Hosoda, and Takayoshi Nakano:
Various New Research Developments Derived from Structural Intermetallic Compounds Research: From New Structural Materials to Biomaterials and Biotissue Research,
Matelia, 51 [4] (2012), pp.168-178.

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Eiji Fukuda received The 18th Japan Institute of Metals and Materials The Metals Best Poster Award at the 150th Spring Meeting of the Japan Institute of Metals.

Eiji Fukuda, Takuya Ishimoto, Wataru Fujitani, and Takayoshi Nakano:
Bone Regeneration Behavior of Novel Directional Porous Implants Fabricated by Electron Beam Additive Manufacturing

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We participated and gave presentations at 2012 spring meeting of The Japan Institute of Metals.

Prof. Nakano, Assistant Profs. Ishimoto, Todai and Serizawa, Research Associate Matsugaki, Technician Fujitani and doctor course students N. Ikeo and E. Fukuda participated and gave oral and/or poster presentations at 2012 spring meeting of The Japan Institute of Metals.

 

E. Fukuda (D1) won the 18th poster award of The Japan Institute of Metals.

 

Y. Umakochi, a professor emeritus at Osaka University, was awarded The Japan Institute of Metals Gold Medal which is the most honorable award of The Japan Institute of Metals. He gave an award lecture. 

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A new book, "Interface Oral Health Science 2011" is available today.

Springer started selling a new book entitled "Interface Oral Health Science 2011" on March 27th, 2012. Prof. Nakano and Assistant Prof. Ishimoto co-authored it.


T. Nakano and T. Ishimoto:

"Interface Oral Health Science 2011", Design of biomaterials for bone replacement based on parameters determining bone quality, Springer, (2011), pp.55-65.

http://www.springer.com/medicine/dentistry/book/978-4-431-54069-4

 

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Our findings will be published as a textbook.

The achievements of Global COE Program: Advanced Structural and Functional Materials Design will be published as a textbook.

Prof. Nakano, Assistant Prof. Ishimoto, Research Associate Matsugaki and a doctor course student N. Ikeo wrote a part of the textbook.

 

Title: Progress in Advanced Structural and Functional Materials Design

Editor: Kakeshita, Tomoyuki (Program Leader)

Publisher: Springer

http://www.springer.com/materials/structural+materials/book/978-4-431-54063-2

ISBN-10 4431540636
ISBN-13 978-4431540632

 

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Prof. Nakano participated and gave an invited lecture at TMS 2012 Annual Meeting & Exhibition.

Prof. Nakano participated and gave an invited lecture at TMS 2012 Annual Meeting & Exhibition held in Orlando, USA.

The title of the lecture was "Some long-period superstructures and the related motion of dislocations in Al-rich TiAl single crystals"

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A paper was published in "Materials Transactions".

Y. Noyama, T. Miura, T. Ishimoto, T. Itaya, M. Niinomi, and T. Nakano:
Bone loss and reduced bone quality of the human femur after total hip arthroplasty under stress-shielding effects by titanium-based implant,
Materials Transactions, 53 [3] (2012), pp.565-570.

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Assistant prof. Ishimoto and a graduate student won the poster award at a symposium for accomplishment report on G-COE program.

Assistant prof. Ishimoto and a doctor course student, N. Ikeo, won the excellent poster award and the poster award, respectively at the 5th symposium of Global COE Program: Advanced Structural and Functional Materials Design Program.

 

T. Ishimoto and T. Nakano:

「生体微量金属元素による骨力学機能化」


N. Ikeo and T. Nakano:

「マクロ・ミクロ構造制御によるインプラント材料の力学機能生体模倣化」 

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Assistant Prof. Ishimoto won the Grand Prize and Dr. Ike'o (D2) won the Excellence Award at the G-COE Achievement Report Meeting.

Takuya Ishimoto, Takayoshi Nakano:
The 5th Symposium of the Global COE Program "Education and Research Center for Advanced Materials Design for Structure and Function,
Best Poster Award,
For "Functionalization of Bone Mechanics by Biological Trace Metal Elements,
March 2, 2012.

Naoko Ikeo and Takayoshi Nakano:
Global COE Program "Education and Research Center for Advanced Materials Design for Structures and Functions" 5th Symposium,
Best Poster Award,
For "Biomimicry of Mechanical Function of Implant Materials by Controlling Macro and Micro Structures,
March 2, 2012.

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Prof. Nakano attended the awards ceremony of JSPS prize.

Prof. Nakano won JSPS prize from the Japanese Applied Physics Society for his study about "Novel Materials Scientific Study on Bone Microstructure and Biomaterials for Bone Replacement".

The 8the award ceremony of JSPS prize was held in the presence of Their Imperial Highnesses Prince and Princess Akishino and The Minister of Education, Culture, Sports, Science and Technology Hirano, on February 27th 2012.

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Our findings have been published in Acta Biomaterialia.

One of cooperative works with Prof. Niinomi's group (Tohoku University) has been published in Acta Biomaterialia.

 

X. Zhao, M. Niinomi, M. Nakai, J. Hieda, T. Ishimoto and T. Nakano:
Optimization of Cr content of metastable β-type Ti–Cr alloys with changeable Young's modulus for spinal fixation applications, Acta Biomaterialia, (2012), DOI:10.1016/j.actbio.2012.02.010.

 

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Our collaborative research results with Prof. Shinya's group at Tohoku University have been accepted and published in Acta Biomaterialia.

X. Zhao, M. Niinomi, M. Nakai, J. Hieda, T. Ishimoto and T. Nakano:
Optimization of Cr content of metastable β-type Ti–Cr alloys with changeable Young’s modulus for spinal fixation applications,
Acta Biomaterialia, (2012).
DOI:10.1016/j.actbio.2012.02.010.

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One of our manuscripts has been accepted for Materials Transactions.

One of our manuscripts has been accepted for Materials Transactions.

 

H. Furuya, S. Matsunaga, Y. Tamatsu, T. Nakano, M. Yoshinari, S. Abe and Y. Ide:
Analysis of biological apatite crystal orientation in the anterior cortical bone of the human mandible using microbeam X-ray diffractometry, Materials Transactions, (2012) in press.

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Five papers were selected as a paper award for Global COE Program: Advanced Structural and Functional Materials Design Program.

Five papers below were selected as a paper award for Global COE Program: Advanced Structural and Functional Materials Design Program. Awarded papers are as follows.

 

N. Ikeo and T. Nakano:

Design and fabrication of porous metal implants with a through-hole aligned along bone axis for bone replacement from the perspective of preferential arrangement of apatite crystallites as a bone quality parameter

Japanese Journal of Clinical Biomechanics, 32 (2011), pp.1-8.

 

T. Ishimoto, T. Nakano, M. Yamamoto and Y. Tabata:

Biomechanical Evaluation of Regenerated Long Bone by Nanoindentation

Journal of Materials Science: in Medicine, 22 [4] (2011), pp.969-976.

 

M. Tane, T. Nakano, S. Kuramoto, M. Hata, M. Niinomi, N. Takesue, T. Yano and H. Nakajima:

Low Young's Modulus in Ti-Nb-Ta-Zr Alloys: Cold Working and Oxygen Effects

Acta Materialia, 59 [18] (2011), pp.6975-6988.

 

M. Todai, T. Fukuda, T. Kakeshita:

Relation between incommensurate satellites and phonon softening in Ti-Ni-based shape memory alloys

Scripta Materialia, 64 [6] (2011), pp. 541-543.

 

K. Hagihara and T. Nakano:

Fracture behavior and toughness of NbSi2-based single-crystals and MoSi2(C11b)/NbSi2(C40) duplex crystals with a single set of lamellae

Acta Materialia, 59 (2011), pp.4168-4176.

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Two papers were selected as one of highlighted papers in "Engineering" category of Annual Report of Osaka University Academic Achievement 2010-2011.

Two papers below were selected as one of highlighted papers in "Engineering" category of Annual Report of Osaka University Academic Achievement 2010-2011.

K. Hagihara and T. Nakano:

Fracture Behavior and Toughness of NbSi2-based Single Crystals and MoSi2 (C11b)/NbSi2(C40) Duplex Crystals with a Single Set of Lamellae, Acta Materialia, 59 (2011) pp.4168-4176.

M. Tane ,S. Akita, T. Nakano, K. Hagihara, Y. Umakoshi, M. Niinomi, H. Mori and H. Nakajima:

Low Young’s Modulus of Ti-Nb-Ta-Zr alloys Caused by Softening in Shear Moduli c’ and c 44 near Lower Limit of Body-centered Cubic Phase Stability, Acta Materialia, 58 (2010) pp.6970-6978. 

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One of our manuscripts has been accepted for Journal of Alloys and Compounds.

A paper about our findings of the collaborative research with Sumitomo Metal Industries, Ltd has been accepted for Journal of Alloys and Compounds.

K. Hayashi, K. Miyata, F. Katsuki, T. Ishimoto and T. Nakano:
Individual mechanical properties of ferrite and martensite in Fe-0.16 mass% C-1.0mass% Si-1.5 mass% Mn steel

 

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Two papers were selected as one of highlighted papers in "Engineering" category of Annual Report of Osaka University Academic Achievement 2010-2011.

Two papers below were selected as one of highlighted papers in "Engineering" category of Annual Report of Osaka University Academic Achievement 2010-2011.

K. Hagihara and T. Nakano:
Fracture Behavior and Toughness of NbSi2-based Single Crystals and MoSi2 (C11b)/NbSi2(C40) Duplex Crystals with a Single Set of Lamellae, Acta Materialia, 59 (2011) pp.4168-4176.

 M. Tane, S. Akita, T. Nakano, K. Hagihara, Y. Umakoshi, M. Niinomi, H. Mori and H. Nakajima:
Low Young’s Modulus of Ti-Nb-Ta-Zr alloys Caused by Softening in Shear Moduli c’ and c44 near Lower Limit of Body-centered Cubic Phase Stability, Acta Materialia, 58 (2010) pp.6970-6978.

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Prof. Nakano won JSPS prize for his study titled "Novel Materials Scientific Study on Bone Microstructure and Biomaterials for Bone Replacement".

Prof. Nakano was awarded for his study titled "Novel Materials Scientific Study on Bone Microstructure and Biomaterials for Bone Replacement" by JSPS. The award ceremony will be held on February 27th, 2012 at Japan Academy.

 

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Prof. Nakano gave a lecture at 11th Osaka University Medical Engineering and Informatics Symposium.

Following the fusion of bio and mechatronics in medicine, engineering, and informatics, a kick-off symposium was held by in September 2011 in order to introduce what is happening now and what to expect in the future regarding the creation of hybrid body organs.

This was the 11th symposium will focus attention on the introduction of advances in prosthetics, particularly on artificial joints and what to look for in the coming weeks and months. Prof. Nakano gave a lecture at the symposium. 

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A graduate student won the poster award at a symposium.

A master course student, Gento Aramoto, won the poster award at 3rd symposium of Society for the Study of material properties.

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【At the awards ceremony】       

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2011

Mr. Yusuke Fujii and Mr. Takahiro Itaya were awarded at the Materials Development Research Meeting of the Kansai Branch of the Iron and Steel Institute of Japan and the Japan Institute of Metals and Materials.

The Japan Iron and Steel Institute and The Japan Institute of Metals and Materials Kansai Branch Materials Development Research Group held the 3rd meeting in 2011 at Osaka University.
In the scientific lecture, Dr. Takashi Sugimoto of Kansai University gave a special lecture.
In the student poster session, Mr. Yusuke Fujii of our laboratory won the Best Poster Award, and Mr. Takahiro Itaya won the Poster Award.

〇Yusuke Fujii, Koji Hagiwara, Takayoshi Nakano:
Crystallographic Analysis for Development of Novel Wear-Resistant Implants Using Single Crystal Co-Cr-Mo Alloys for Biomedical Applications,
The Japan Iron and Steel Institute and The Japan Institute of Metals and Materials Kansai Branch Materials Development Research Group, the Best Poster Award, Osaka University, 2011, 1215.

〇Takahiro Itaya, Takuya Ishimoto, Sayaka Miyabe, and Takayoshi Nakano:
Elucidation of the orientation mechanism of human femoral cancellous bone for the development of new hip joint implants,
The Japan Iron and Steel Institute and The Japan Institute of Metals and Materials Kansai Branch Materials Development Research Group, the Poster Award, Osaka University, 2011, 1215.

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One of our manuscripts has been accepted for Materials Transactions.

One of our manuscripts has been accepted for Materials Transactions.

Y. Noyama, T. Miura, T. Ishimoto, T. Itaya, M. Niinomi, and T. Nakano:

Bone loss and reduced bone quality of the human femur after total hip arthroplasty under stress-shielding effects by titanium-based implant

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One of our papers about single crystal of Ti alloy was selected as a free-access paper.

One of our papers about single crystal of Ti alloy was selected as a free-access paper. Paper has been available at http://www.springerlink.com/content/w0485624943771v6/

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Ms. Ikeo (D2) won the ECO-MATES 2011 PROMOTION AWARD at ECO-MATES 2011.

N. Ikeo, T.Ishomoto, T. Nakano:
Fabrication of three dimensional structures by EBM method,
ECO-MATES 2011, the ECO-MATES 2011 PROMOTION AWARD, 2011, 1130.

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A graduate student won the poster award at a symposium.

An award ceremony was held at the 38th Japanese Society for Clinical Biomechanics. A doctor course student, Naoko Ikeo, won the award. 

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Prof. Nakano wan a paper award at the 59th Japan Institute of Metals.

Prof. Nakano wan a paper award of the 59th Japan Institute of Metals at 2011 annual fall meeting for the paper titled below.

T. Nagase, T. Nakano. Y. Umakoshi and M. Niinomi: Fabrication of Beta-Ti-Type Ti-Nb-Ta-Zr (TNTZ) Wire with Hjgh-Ductility by Arc-Melt-Type Melt-Extraction Method, Matrials Transactions, Vol. 51, No. 2 (2010), pp.377-380 

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A graduate student won the poster award at the 149th annual fall meeting of The Japan Institute of Metals.

The 149th annual fall meeting of The Japan Institute of Metals was held at Okinawa. Two master course students, Bunji Sato and Munetaka Horita, won the 17th poster award of The Japan Institute of Metals. 

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Science Café was held.

A Science Café on October 28th at Osaka station. Prof. Nakano gave a lecture titled "Let's talk about bone".

The event was introduced on the official home page of Osaka University.

→  http://www.lserp.osaka-u.ac.jp/info/20111028report.html 

 

 

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The paper by Dr. Ike'o and his colleagues, published in the Journal of Japanese Society for Clinical Biomechanics, was selected as the "Society's Encouragement Award Paper".

Naoko Ikeo, Takayoshi Nakano:
Design and Development of Directional Porous Implants for Bone Replacement Considering Apatite Orientation as Bone Quality,
the Journal of Japanese Society for Clinical Biomechanics, 32(2011), pp1-8.

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Our paper on stress calculation of trabecular bone has been published in the proceedings of the 24th JSME Conference on Computational Mechanics.

K. S. Basaruddin, Y. Yoshiwara, N. Takano, T. Nakano and T. Ishimoto:
Prediction of macroscopic properties of vertebral trabecular bone and comparison with Keyak’s model,
the 24th JSME Conference on Computational Mechanics, (2011), pp.F45-F46.

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Our findings have been published in Dental Materials, Elsevier.

One of cooperative works with Prof. T. Matsumoto's group (Okayama Uni.) and Prof. S. Imazato's group (Osaka Univ.) has been published in Dental Materials, Elsevier.

 T. Jr. Matsumoto, S.-H. An, T. Ishimoto, T. Nakano, T. Matsumoto and S. Imazato:
Zirconia-hydroxyapatite composite material with micro porous structure, Dental Materials 27 [11] (2011), pp.e205-e212. 

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One of our manuscripts has been accepted for Metallurgical and Material Transactions A.

5th, October
One of our manuscripts has been accepted for Metallurgical and Material Transactions A.
The title is "Microstructual and orientation dependence of the plastic deformation behavior in β-type Ti-15Mo-5Zr-3Al alloys single crystals" by Mr. S.-H. Lee, Dr. K. Hagihara and Prof. T. Nakano. 

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The Japan Institute of Metals and Materials and The Iron and Steel Institute of Japan Kansai Branch Materials Science and Engineering Conference was held, and Mr. Keita Kawahara, M2 of our laboratory won the "Excellent Poster Award" in the poster presenta

The Japan Institute of Metals and Materials and The Iron and Steel Institute of Japan Kansai Branch Materials Science and Engineering Conference was held, and Mr. Keita Kawahara, M2 of our laboratory won the "Excellent Poster Award" in the poster presentation session. (For "Elucidation of the control mechanism of bone apatite orientation focusing on osteocytes using a materials science approach")

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2010

August 2-6, 2010, Cairns, Australia

Professor Nakano gave a keynote lecture entitled “Evaluation and control of crystallographic alignment of biological apatite crystallites in bones” at the 7th Pacific Rim International Conference on Advanced Materials and Processing (PRICM7). Drs. Ishimoto, Fujitani, and Lee and Mr. Noyama also presented their research results.

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2009

December 12-14, 2009, Sendai, Japan

Professor Nakano, Mr. Sakamoto (master student), Dr. Hagihara (collaborator) attended the 18th Processing and Fabrication of Advanced Materials (PFAM18). Professor Nakano gave an invited talk and Mr. Sakamoto gave a poster presentation.
This photo was taken during a coffee break.
Professor Miura of Kyushu University (second from left), Professor Nakano (leftmost), and Dr, Madhav Reddy of Indian Institute of Technology (second from right).

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August 25-29, 2009, Berlin, Germany

Drs. Ishimoto and Lee and Mr. Noyama participated in the International Conference on Processing & Manufacturing of Advanced Materials (THERMEC' 2009). Drs. Ishimoto and Lee gave oral presentations and Mr. Noyama presented at a poster session.

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2008

December 1-4, 2008, Boston, The United States

Professor Nakano participated in the Materials Research Society Fall Meeting. He acted as chairperson and gave presentations in biomaterials and Intermetallics sessions. In this picture, Professor Nakano (right) is with Takeyama Masao of Tokyo Institute of Technology (left) and Dr. Martin Palm of Max Plank Society for the Advancement of Science, Germany (center) in the Intermetallics session.

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May 28-June 1, 2008, Amsterdam, Netherlands

Professor Nakano, Assistant Professor Ishimoto, and Dr. Lee gave oral and poster presentations at the 8th World Biomaterials Congress.

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●Conference venue in Amsterdam

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● Professor Nakano and Associate Professor Ishimoto at the conference venue

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● With Professor Boskey

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● At a banquet (starting from the left: Professor Suzuki (Tohoku University Graduate School of Dentistry), Dr. S.-E. Kim (Korea Institute of Material Science), Mrs. Niinomi, Professor Niinomi (The Institute for Materials Research, Tohoku University), Professor Tabata (Institute for Frontier Medical Sciences, Kyoto University), Dr. Taguchi (NIMS), Dr. Yamamoto (Institute for Frontier Medical Sciences, Kyoto University), Professor Hanawa (Institute of Biomedicals and Bioengineering, Tokyo Medical and Dental University) and Professor Nakano)

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● With Professor Hanawa (Tokyo Medical and Dental University・Institute of Biomedicals and Bioengineering) in front of a windmill
 

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April 25, 2008, Korea

Kumoh National University of Technology (KIT)

Professor Nakano gave an invited educational lecture.

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● Professor Nakano at the lecture

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