1
|
Indurkar A, Kudale P, Rjabovs V, Heinmaa I, Demir Ö, Kirejevs M, Rubenis K, Chaturbhuj G, Turks M, Locs J. Small organic molecules containing amorphous calcium phosphate: synthesis, characterization and transformation. Front Bioeng Biotechnol 2024; 11:1329752. [PMID: 38283170 PMCID: PMC10811600 DOI: 10.3389/fbioe.2023.1329752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 12/13/2023] [Indexed: 01/30/2024] Open
Abstract
As the primary solid phase, amorphous calcium phosphate (ACP) is a pivotal precursor in cellular biomineralization. The intrinsic interplay between ACP and Howard factor underscores the significance of understanding their association for advancing biomimetic ACP development. While organic compounds play established roles in biomineralization, this study presents the synthesis of ACP with naturally occurring organic compounds (ascorbate, glutamate, and itaconate) ubiquitously found in mitochondria and vital for bone remodeling and healing. The developed ACP with organic compounds was meticulously characterized using XRD, FTIR, and solid-state 13C and 31P NMR. The morphological analysis revealed the characteristic spherical morphology with particle size close to 20 nm of all synthesized ACP variants. Notably, the type of organic compound strongly influences true density, specific surface area, particle size, and transformation. The in vitro analysis was performed with MC3T3-E1 cells, indicating the highest cell viability with ACP_ASC (ascorbate), followed by ACP_ITA (itaconate). The lowest cell viability was observed with 10 %w/v of ACP_GLU (glutamate); however, 1 %w/v of ACP_GLU was cytocompatible. Further, the effect of small organic molecules on the transformation of ACP to low crystalline apatite (Ap) was examined in Milli-Q® water, PBS, and α-MEM.
Collapse
Affiliation(s)
- Abhishek Indurkar
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| | - Pawan Kudale
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai, India
| | - Vitālijs Rjabovs
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Ivo Heinmaa
- National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Öznur Demir
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| | - Matvejs Kirejevs
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Kristaps Rubenis
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| | - Ganesh Chaturbhuj
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai, India
| | - Māris Turks
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Janis Locs
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| |
Collapse
|
2
|
Yokoi T, Watanabe M, Nakamura F, Kimura-Suda H, Shimabukuro M, Kawashita M. Formation of octacalcium phosphate with incorporated dicarboxylate ions containing disulfide bonds. Dalton Trans 2023; 52:16586-16590. [PMID: 37860980 DOI: 10.1039/d3dt02462h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Octacalcium phosphate (OCP) is a layered compound capable of incorporating carboxylate ions within its interlayer structure. In this study, we successfully synthesised OCP with incorporated 3,3'-dithiodipropionate ions. Our finding is beneficial for the development of novel OCP-based materials with dynamic properties derived from disulfide bonds.
Collapse
Affiliation(s)
- Taishi Yokoi
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
| | - Masahiro Watanabe
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
| | - Fumiya Nakamura
- Chitose Institute of Science and Technology (CIST), 758-65 Bibi, Chitose, Hokkaido 066-8655, Japan
| | - Hiromi Kimura-Suda
- Chitose Institute of Science and Technology (CIST), 758-65 Bibi, Chitose, Hokkaido 066-8655, Japan
| | - Masaya Shimabukuro
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
| | - Masakazu Kawashita
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
| |
Collapse
|
3
|
Kuroyama K, Fujikawa R, Goto T, Sekino T, Nakamura F, Kimura-Suda H, Chen P, Kanetaka H, Hasegawa T, Yoshida K, Murata M, Nakata H, Shimabukuro M, Kawashita M, Yoda T, Yokoi T. Development of bioinspired damage-tolerant calcium phosphate bulk materials. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2023; 24:2261836. [PMID: 37842650 PMCID: PMC10572054 DOI: 10.1080/14686996.2023.2261836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/18/2023] [Indexed: 10/17/2023]
Abstract
Improving the damage tolerance and reliability of ceramic artificial bone materials, such as sintered bodies of hydroxyapatite (HAp), that remain in vivo for long periods of time is of utmost importance. However, the intrinsic brittleness and low damage tolerance of ceramics make this challenging. This paper reports the synthesis of highly damage tolerant calcium phosphate-based materials with a bioinspired design for novel artificial bones. The heat treatment of isophthalate ion-containing octacalcium phosphate compacts in a nitrogen atmosphere at 1000°C for 24 h produced an HAp/β-tricalcium phosphate/pyrolytic carbon composite with a brick-and-mortar structure (similar to that of the nacreous layer). This composite exhibited excellent damage tolerance, with no brittle fracture upon nailing, likely attributable to the specific mechanical properties derived from its unique microstructure. Its maximum bending stress, maximum bending strain, Young's modulus, and Vickers hardness were 11.7 MPa, 2.8 × 10‒2, 5.3 GPa, and 11.7 kgf/mm2, respectively. The material exhibited a lower Young's modulus and higher fracture strain than that of HAp-sintered bodies and sintered-body samples prepared from pure octacalcium phosphate compacts. Additionally, the apatite-forming ability of the obtained material was confirmed in vitro, using a simulated body fluid. The proposed bioinspired material design could enable the fabrication of highly damage tolerant artificial bones that remain in vivo for long durations of time.
Collapse
Affiliation(s)
- Karen Kuroyama
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), Chiyoda-ku, Japan
- Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Japan
| | - Ryuichi Fujikawa
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), Chiyoda-ku, Japan
| | - Tomoyo Goto
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Osaka, Japan
- Institute for Advanced Co-Creation Studies, Osaka University, Suita, Osaka, Japan
| | - Tohru Sekino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Osaka, Japan
| | - Fumiya Nakamura
- Graduate School of Science and Technology, Chitose Institute of Science and Technology (CIST), Chitose, Hokkaido, Japan
| | - Hiromi Kimura-Suda
- Department of Applied Chemistry and Bioscience, Faculty of Science and Technology, Chitose Institute of Science and Technology, Chitose, Hokkaido, Japan
| | - Peng Chen
- Division of Interdisciplinary Co-Creation (ICC-Division), Liaison Center for Innovative Dentistry, Graduate School of Dentistry, Tohoku University, Sendai, Japan
| | - Hiroyasu Kanetaka
- Division of Interdisciplinary Co-Creation (ICC-Division), Liaison Center for Innovative Dentistry, Graduate School of Dentistry, Tohoku University, Sendai, Japan
| | - Tomoka Hasegawa
- Developmental Biology of Hard Tissue, Faculty of Dental Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Kaname Yoshida
- Nanostructures Research Laboratory, Japan Fine Ceramics Center, Aichi, Japan
| | - Masaru Murata
- Division of Oral Regenerative Medicine, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan
| | - Hidemi Nakata
- Department of Oral Implantology and Regenerative Dental Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Japan
| | - Masaya Shimabukuro
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), Chiyoda-ku, Japan
| | - Masakazu Kawashita
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), Chiyoda-ku, Japan
| | - Tetsuya Yoda
- Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Japan
| | - Taishi Yokoi
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), Chiyoda-ku, Japan
| |
Collapse
|
4
|
Murphy B, Morris MA, Baez J. Development of Hydroxyapatite Coatings for Orthopaedic Implants from Colloidal Solutions: Part 2-Detailed Characterisation of the Coatings and Their Growth Mechanism. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2606. [PMID: 37764634 PMCID: PMC10535467 DOI: 10.3390/nano13182606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/12/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023]
Abstract
This study is the second part of a two-part study whereby supersaturated solutions of calcium and phosphate ions generate well-defined hydroxyapatite coatings for orthopaedic implants. An 'ideal' process solution is selected from Part 1, and the detailed characterisation of films produced from this solution is undertaken here in Part 2. Analysis is presented on the hydroxyapatite produced, in both powder form and as a film upon titanium substrates representative of orthopaedic implants. From thermal analysis data, it is shown that there is bound and interstitial water present in the hydroxyapatite. Nuclear magnetic resonance data allow for the distinction between an amorphous and a crystalline component of the material. As hydroxyapatite coatings are generated, their growth mechanism is tracked across repeated process runs. A clear understanding of the growth mechanism is achieved though crystallinity and electron imaging data. Transmission electron imaging data support the proposed crystal growth and deposition mechanism. All of the data conclude that this process has a clear propensity to grow the hydroxyapatite phase of octacalcium phosphate. The investigation of the hydroxyapatite coating and its growth mechanism establish that a stable and reproducible process window has been identified. Precise control is achieved, leading to the successful formation of the desired hydroxyapatite films.
Collapse
Affiliation(s)
- Bríd Murphy
- Advanced Materials & Bioengineering Research Centre (AMBER), Trinity College Dublin, D02 CP49 Dublin 2, Ireland;
- School of Chemistry, Trinity College Dublin, D02 PN40 Dublin 2, Ireland
| | - Mick A. Morris
- Advanced Materials & Bioengineering Research Centre (AMBER), Trinity College Dublin, D02 CP49 Dublin 2, Ireland;
- School of Chemistry, Trinity College Dublin, D02 PN40 Dublin 2, Ireland
| | - Jhonattan Baez
- Advanced Materials & Bioengineering Research Centre (AMBER), Trinity College Dublin, D02 CP49 Dublin 2, Ireland;
- School of Chemistry, Trinity College Dublin, D02 PN40 Dublin 2, Ireland
| |
Collapse
|
5
|
Indurkar A, Choudhary R, Rubenis K, Nimbalkar M, Sarakovskis A, Boccaccini AR, Locs J. Amorphous Calcium Phosphate and Amorphous Calcium Phosphate Carboxylate: Synthesis and Characterization. ACS OMEGA 2023; 8:26782-26792. [PMID: 37546623 PMCID: PMC10399191 DOI: 10.1021/acsomega.3c00796] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 06/27/2023] [Indexed: 08/08/2023]
Abstract
Amorphous calcium phosphate (ACP) is the first solid phase precipitated from a supersaturated calcium phosphate solution. Naturally, ACP is formed during the initial stages of biomineralization and stabilized by an organic compound. Carboxylic groups containing organic compounds are known to regulate the nucleation and crystallization of hydroxyapatite. Therefore, from a biomimetic point of view, the synthesis of carboxylate ions containing ACP (ACPC) is valuable. Usually, ACP is synthesized with fewer steps than ACPC. The precipitation reaction of ACP is rapid and influenced by pH, temperature, precursor concentration, stirring conditions, and reaction time. Due to phosphates triprotic nature, controlling pH in a multistep approach becomes tedious. Here, we developed a new ACP and ACPC synthesis approach and thoroughly characterized the obtained materials. Results from vibration spectroscopy, nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), true density, specific surface area, and ion release studies have shown a difference in the physiochemical properties of the ACP and ACPC. Additionally, the effect of a carboxylic ion type on the physiochemical properties of ACPC was characterized. All of the ACPs and ACPCs were synthesized in sterile conditions, and in vitro analysis was performed using MC-3T3E1 cells, revealing the cytocompatibility of the synthesized ACPs and ACPCs, of which the ACPC synthesized with citrate showed the highest cell viability.
Collapse
Affiliation(s)
- Abhishek Indurkar
- Rudolfs
Cimdins Riga Biomaterials Innovations and Development Centre of RTU,
Institute of General Chemical Engineering, Faculty of Materials Science
and Applied Chemistry, Riga Technical University, Pulka Street 3, LV-1007 Riga, Latvia
- Baltic
Biomaterials Centre of Excellence, Headquarters
at Riga Technical University, Kipsalas Street 6A, LV-1048 Riga, Latvia
| | - Rajan Choudhary
- Rudolfs
Cimdins Riga Biomaterials Innovations and Development Centre of RTU,
Institute of General Chemical Engineering, Faculty of Materials Science
and Applied Chemistry, Riga Technical University, Pulka Street 3, LV-1007 Riga, Latvia
- Baltic
Biomaterials Centre of Excellence, Headquarters
at Riga Technical University, Kipsalas Street 6A, LV-1048 Riga, Latvia
| | - Kristaps Rubenis
- Rudolfs
Cimdins Riga Biomaterials Innovations and Development Centre of RTU,
Institute of General Chemical Engineering, Faculty of Materials Science
and Applied Chemistry, Riga Technical University, Pulka Street 3, LV-1007 Riga, Latvia
- Baltic
Biomaterials Centre of Excellence, Headquarters
at Riga Technical University, Kipsalas Street 6A, LV-1048 Riga, Latvia
| | | | - Anatolijs Sarakovskis
- Institute
of Solid State Physics, University of Latvia, 8 Kengaraga Str., LV-1063 Riga, Latvia
| | - Aldo R. Boccaccini
- Institute
of Biomaterials, Department of Material Science and Engineering, University of Erlangen-Nuremberg, 91085 Erlangen, Germany
| | - Janis Locs
- Rudolfs
Cimdins Riga Biomaterials Innovations and Development Centre of RTU,
Institute of General Chemical Engineering, Faculty of Materials Science
and Applied Chemistry, Riga Technical University, Pulka Street 3, LV-1007 Riga, Latvia
- Baltic
Biomaterials Centre of Excellence, Headquarters
at Riga Technical University, Kipsalas Street 6A, LV-1048 Riga, Latvia
| |
Collapse
|
6
|
Indurkar A, Choudhary R, Rubenis K, Locs J. Role of carboxylic organic molecules in interfibrillar collagen mineralization. Front Bioeng Biotechnol 2023; 11:1150037. [PMID: 37091348 PMCID: PMC10113455 DOI: 10.3389/fbioe.2023.1150037] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/20/2023] [Indexed: 04/07/2023] Open
Abstract
Bone is a composite material made up of inorganic and organic counterparts. Most of the inorganic counterpart accounts for calcium phosphate (CaP) whereas the major organic part is composed of collagen. The interfibrillar mineralization of collagen is an important step in the biomineralization of bone and tooth. Studies have shown that synthetic CaP undergoes auto-transformation to apatite nanocrystals before entering the gap zone of collagen. Also, the synthetic amorphous calcium phosphate/collagen combination alone is not capable of initiating apatite nucleation rapidly. Therefore, it was understood that there is the presence of a nucleation catalyst obstructing the auto-transformation of CaP before entering the collagen gap zone and initiating rapid nucleation after entering the collagen gap zone. Therefore, studies were focused on finding the nucleation catalyst responsible for the regulation of interfibrillar collagen mineralization. Organic macromolecules and low-molecular-weight carboxylic compounds are predominantly present in the bone and tooth. These organic compounds can interact with both apatite and collagen. Adsorption of the organic compounds on the apatite nanocrystal governs the nucleation, crystal growth, lattice orientation, particle size, and distribution. Additionally, they prevent the auto-transformation of CaP into apatite before entering the interfibrillar compartment of the collagen fibril. Therefore, many carboxylic organic compounds have been utilized in developing CaP. In this review, we have covered different carboxylate organic compounds governing collagen interfibrillar mineralization.
Collapse
Affiliation(s)
- Abhishek Indurkar
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| | - Rajan Choudhary
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| | - Kristaps Rubenis
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
| | - Janis Locs
- Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
- *Correspondence: Janis Locs,
| |
Collapse
|
7
|
Yokoi T, Watanabe M, Goto T, Meng S, Sekino T, Shimabukuro M, Kawashita M. Synthesis of Octacalcium Phosphate Containing Glutarate Ions with a High Incorporation Fraction. MATERIALS (BASEL, SWITZERLAND) 2022; 16:64. [PMID: 36614402 PMCID: PMC9821757 DOI: 10.3390/ma16010064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Octacalcium phosphate (OCP) has received considerable attention in the field of ceramic biomaterials as an advanced functional material. It exhibits a layered structure composed of apatitic and hydrated layers and can incorporate various dicarboxylate ions into the hydrated layer. Saturated dicarboxylic acids (HOOC(CH2)nCOOH) with an odd number of methylene groups (-CH2-) exhibit lower incorporation fractions than those with an even number of methylene groups, possibly owing to a compositional dependence on the synthetic method. In this study, calcium carbonate, phosphoric acid, and various amounts of glutaric acid were used to produce glutarate-ion-incorporated OCP by a wet chemical method, which is different from the conventional synthetic strategy. While utilising 1-20 mmol of glutaric acid during synthesis did not produce the desired product, using 25 mmol of glutaric acid resulted in the formation of single-phase glutarate-ion-incorporated OCP with a Ca/P molar ratio of 1.57 and a 90% incorporation fraction of glutarate ions. This glutarate-ion-incorporation fraction is significantly higher than that reported in the previous studies (35%). Thus, the synthetic procedure proposed herein was able to produce single-phase OCP containing glutarate ions with a high incorporation fraction. Our findings can contribute to development of novel functional ceramic biomaterials in the future.
Collapse
Affiliation(s)
- Taishi Yokoi
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Masahiro Watanabe
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Tomoyo Goto
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mohogaoka, Ibaraki, Osaka 567-0047, Japan
- Institute for Advanced Co-Creation Studies, Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Sikun Meng
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Tohru Sekino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mohogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Masaya Shimabukuro
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Masakazu Kawashita
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| |
Collapse
|