In Vitro Hydroxycarbonate Apatite Mineralization of CaO-SiO2 Sol-gel Glasses with a Three-Dimensionally Ordered Macroporous Structure

A three-dimensionally ordered macroporous (3DOM) bioactive glass with a composition of 80 mol% SiO2 and 20 mol% CaO was synthesized by the sol-gel method using poly(methylmethacrylate) (PMMA) colloidal crystals templates. A control sample with matching composition was prepared by the same process but without PMMA templating. In vitro hydroxycarbonate apatite growth was investigated by soaking the bioactive glass in simulated body fluid (SBF) at body temperature (37°C) for varying lengths of time. The formation of a hydroxycarbonate apatite layer on the glass was studied by XRD, SEM, TEM, FTIR, and ICP. The effects of loading amount and calcination temperature on the in vitro mineralization process were investigated. The 3DOM bioactive glass exhibited faster growth of apatite than the non-templated control sample, probably due to its more accessible surface.