Abstract
Polydimethylsiloxane (PDMS)–CaO–SiO2 hybrids with starting compositions containing PDMS/(Si(OC2H5)4+PDMS) weight ratio=0.30, H2O/Si(OC2H5)4 molar ratio=2, and Ca(NO3)2/Si(OC2H5)4 molar ratios=0–0.2, were prepared by the sol–gel method. The apatite-forming ability of the hybrids increased with increasing calcium content in the Ca(NO3)2/Si(OC2H5)4 molar ratio range 0–0.1. The hybrids with a Ca(NO3)2/Si(OC2H5)4 molar ratio range 0.1–0.2 formed apatite on their surfaces in a simulated body fluid (SBF) within 12 h. The hybrid with a Ca(NO3)2/Si(OC2H5)4 molar ratio of 0.10 showed an excellent apatite-forming ability in SBF with a low release of silicon into SBF. It also showed mechanical properties analogous to those of human cancellous bones. This hybrid is expected to be useful as a new type of bioactive material.