What's New
2017（January－June）
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2017.6.26
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2017.6.23
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2017.6.22
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2017.6.21
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2017.6.17
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2017.6.17
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2017.6.15
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2017.6.12
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2017.6.12
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2017.5.15
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2017.5.15
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2017.5.5
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2017.5.1
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2017.4.7
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2017.3.21
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2017.3.18
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2017.3.16
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2017.2.1
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2017.1.31
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2017.1.14
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2017.6.26
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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2017.6.23
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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2017.6.22
An article on the results of the development of ultra-high temperature resistant materials was published in the Nikkan Kogyo Shimbun on June 22.
Click here for this article.
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2017.6.21
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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2017.6.17
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.2017.05.006Abstract
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 dentistryClick here for this paper.
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2017.6.17
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.Click here for more information.
＜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.Click here for more information.
＜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.Click here for more information.
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2017.6.15
An article about our laboratory's research was published in the June issue of Monthly Municipal Solutions (pages 73-75).
Click here for more details.
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2017.6.12
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.126-131Abstract
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.
Click here for this paper.
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2017.6.12
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/s41598-017-03628-6Abstract
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.
Click here for this paper.
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2017.5.15
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)Click here for this PDF.
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2017.5.15
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.8-20Click here for this PDF.
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2017.5.5
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.2017.05.014Abstract
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.
Click here for this paper.
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2017.5.1
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-yAbstract
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. -
2017.4.7
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. -
2017.3.21
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.
Click here for this article.
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2017.3.18
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/srep44824Abstract
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.Click here for this paper.
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2017.3.16
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. -
2017.2.1
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. -
2017.1.31
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.2016.12.038Abstract
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.Click here for this paper.
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2017.1.14
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.2017.01.004Abstract
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.
Click here for this paper.