title: Bioactivity and mechanical properties of PDMS-modified CaO-SiO(2)-TiO(2) hybrids prepared by sol-gel process.
abstract: Hydrolysis and polycondensation of poly(dimethylsiloxane) (PDMS), tetraethoxysilane (TEOS), tetraisopropyltitanate (TiPT), and calcium nitrate gave essentially pore- and crack-free transparent monolithics of PDMS-modified CaO-SiO(2)-TiO(2) hybrids, when PDMS/(TEOS + TiPT) was larger than 26:74 in weight, under constant ratios of TEOS/TiPT of 9:1 in mol and Ca/(TEOS + TiPT) of 0.15 in mol. Their apatite-forming abilities in a simulated body fluid, which is indicative of bioactivity, increased with decreasing PDMS/(TEOS + TiPT). Their extensibility and Young's modulus decreased and increased, respectively, with decreasing PDMS/(TEOS + TiPT). The hybrids with PDMS/(TEOS + TiPT) of about 30:70 in weight showed fairly high apatite-forming ability, high extensibilities, and Young's moduli almost equal to those of the human cancellous bones. These new kind of bioactive materials with unique mechanical properties may be useful as bone-repairing materials.
authors.affiliation: Department of Material Chemistry, Faculty of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Q
authors.initials: Q
authors.lastname: Chen
authors.forename: N
authors.initials: N
authors.lastname: Miyata
authors.forename: T
authors.initials: T
authors.lastname: Kokubo
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D001031:Apatites / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001696:Biomechanical Phenomena; D018786:Bone Substitutes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D017610:Calcium Compounds; D004129:Dimethylpolysiloxanes; D005782:Gels; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009942:Organometallic Compounds; D010087:Oxides; D012821:Silanes; D012822:Silicon Dioxide; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014025:Titanium
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; D018786:Bone Substitutes; D017610:Calcium Compounds; D004129:Dimethylpolysiloxanes; D005782:Gels; D009942:Organometallic Compounds; D010087:Oxides; D012821:Silanes; C009495:titanium dioxide; C040733:tetraethoxysilane; D012822:Silicon Dioxide; C102815:titanium isopropoxide; C016538:lime; D014025:Titanium