1999 Fiscal Year Final Research Report Summary
Mechanical property and bioactivity of organic-inorganic hybrid materials containing silanol groups
Project/Area Number |
09450246
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Inorganic materials/Physical properties
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Research Institution | Okayama University |
Principal Investigator |
OSAKA Akiyoshi Okayama U., Faculty of Eng., Professor, 工学部, 教授 (20033409)
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Co-Investigator(Kenkyū-buntansha) |
TSURU Kanji Okayama U., Faculty of Eng., Research Associate, 工学部, 助手 (50314654)
HAYAKAWA Satoshi Okayama U., Faculty of Eng., Lecturer, 工学部, 講師 (20263618)
OHTSUKI Chikara Nara Inst. of Sci. & Tech., Grad. Sch. of Mat. Sci., Associate Professor, 物質創成科学研究科, 助教授 (00243048)
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Project Period (FY) |
1997 – 1999
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Keywords | Organic-inorganic hybrid materials / Bioactive materials / Cytocompatibility / Mechanical property / Organically modified ceramics / Cell culture / Apatite / Silanol groups |
Research Abstract |
We synthesized calcium-containing organically modified silicates (Ormosils) starting from ploy (dimethylsiloxane) (PDMS, -(SiO(CHィイD23ィエD2)ィイD22ィエD2)ィイD2nィエD2-), tetraethoxysilane (TEOS), Si(OCィイD22ィエD2HィイD25ィエD2)ィイD24ィエD2) and calcium nitrate (Ca(NOィイD23ィエD2)ィイD22ィエD2 ・ 4HィイD22ィエD2O). One of the typical compositions for starting materials was TEOS : PDMS : HCl : HィイD22ィエD2O : Ca(NOィイD23ィエD2)ィイD22ィエD2 ・ 4HィイD22ィエD2O = 1 : 1.64 : 0.1 : 3 : 0.1 (molar ratio). We investigated effects of HCl and Ca(NOィイD23ィエD2)ィイD22ィエD2 ・ 4HィイD22ィエD2O contents in gelling solutions on bioactivity and microstructure of Ormosils-type samples. Analysis of ィイD129ィエD1Si MAS NMR spectra indicated that amounts of HCl do not show any significant effects for local structure around Si atoms. The SEM-EDX analysis of fracture-surface for Ormosils-type sample showed that the pore size and amount of Ca incorporated in their structure depended on HCl amounts. We concluded that greater bioactivity was attributed to incorpo
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ration of more calcium ions in the polymer due to addition of larger amounts of HCl and /or Ca(NOィイD23ィエD2)ィイD22ィエD2 ・ 4HィイD22ィエD2O. The Ormosils sols prepared from PDMS-TEOS-Ca with /without addition of DMF were coated on Nylon6【R!〇】 and silicone substrates with a dip-coating technique. The coated layer was 1.5μm thickness without cracks. Adhesive strength between the coated films and substrates was not less than about 1.7 MPa. The DMF-free film did not deposit apatite within 14 days while the films from the sols with DMF deposited apatite within 7 days in SBF. The difference in microstructure between film-DMF and DMF-free film explained that in bioactivity. Since AEROSIL【R!〇】 is one of the reinforcement materials for silicone, we synthesized the ORMOSILS gels reinforced with AEROSIL【R!〇】 starting from PDMS, TEOS and Ca(NOィイD23ィエD2)ィイD22ィエD2 ・ 4HィイD22ィエD2O through sol-gel processing. The storage modulus increased with the AEROSIL【R!〇】 content along with the increase in PDMS-AEROSIL【R!〇】 bonds. The gel (molar ratio, TEOS : PDMS : HィイD22ィエD2O : HCl : CA(NOィイD23ィエD2)ィイD22ィエD2 = 1 : 0.24 : 5.0 : 0.9 : 0.25) containing 5g AEROSIL【R!〇】 (F5H0.6Ca0.25) could deposit apatite within 1 day of soaking in the Kokudo solution, since F5H0.6Ca0.25 included many calcium ions on the surface. Cytocompatibility of organic-inorganic hybrids reinforced with AEROSIL【R!〇】 was examined. Osteoblast-like cells (MC3T3-E1) derived from mouse were cultured on the specimens at 36.5℃ under 5% and 95% humidity. Cell numbers with specimen after incubation for 3 and 7days showed higher degree of proliferation than that without specimen denoted as "blank". However, it was not appreciable because the cell numbers of blank after incubation for 3 and 7days reduced by 1/10 in comparison with usual case in cell examination. Anyway, this results indicated that the hybrids did not show cytotoxicity. Less
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Research Products
(12 results)