In vitro bioactivity of polymer matrices reinforced with a bioactive glassphase

Composites that can mimic the in vitro bioactive behavior of bioactive glas ses were designed to fulfill two main features of bioactive glasses that ar e responsible for their high bond-to-bone rates: (1) capability of providin g ions such as calcium and phosphate to the nearby environment and (2) idea l surface structure that allows fast heterogeneous precipitation of hydroxy -carbonate-apatite (HCA). The novel composites were prepared by incorporati ng bioactive glass particles into polymer matrices. The in vitro bioactivit y test was performed by introducing samples into a buffered solution as wel l as into a simulated body fluid solution. FTIR was used to evaluate the ki netics of HCA (hydroxy-carbonate-apatite) precipitation. The results showed that the obtained composites can supply ions, such as silicates and phosph ates in rates and concentrations comparable or superior than bulk bioactive glasses. Moreover, the surface chemistry of the composites was altered to mimic the surface of bioactive glasses. It was demonstrated that the in vit ro bioactivity of the composites was enhanced by chemically modifying polym er surfaces through the introduction of special alkoxysilane groups.