Precipitation of anatase in silicone and bioactivity of the products

Silicone was soaked in tetraisopropyltitanate (TiPT) at 30°C for various periods and then subsequently soaked in water at 25°C, an HCl solution at 25°C, an NH₃ solution at 25°C or hot water at 80°C for 24 d. It precipitated nano-sized anatase particles in it when it was soaked in hot water after soaking in TiPT, whereas it did not precipitate the anatase when soaked in any solution at 25°C after soaking in TiPT. The amount of the precipitated anatase increased with increasing period of soaking in TiPT before hot water treatment. The silicone in which anatase was precipitated formed apatite on it in a simulated body fluid (SBF) within seven days. The amount of the precipitated apatite increased with increasing amount of the precipitated anatase. The silicone precipitated with anatase is expected to form apatite on its surface even in the living body and bond to living bone through the apatite. The tensile strength and strain to failure of the silicone decreased by soaking in TiPT and subsequently soaking in hot water, whereas their Young's modulus increased.