Apatite formation on PDMS-modified CaO-SiO2-TiO2 hybrids prepared by sol-gel process.

Dense and homogeneous monolithics of polydimethylsiloxane (PDMS)-modified CaO-SiO2-TiO2 hybrids were successfully synthesized by sol-gel process. They were assumed to be composed of a silica and titania network incorporated with PDMS and the calcium ion ionically bonded to the network. Among them, the hybrids containing relatively larger amounts of the calcium in their surfaces formed an apatite on their surfaces within only 1 or 0.5 day in a simulated body fluid with ion concentrations nearly equal to those of human flood plasma. This indicates that they are highly bioactive. Organic-inorganic hybrids synthesized by a sol-gel process usually exhibit high ductility, low elastic modulus and high mechanical strength. The present hybrids are, therefore, expected to be useful as a new kind of bone-repairing material, because of their high bioactivity and unique mechanical properties.