In vitro Degradation, Bioactivity, and Cytocompatibility of Calcium Silicate, Dimagnesium Silicate, and Tricalcium. Phosphate Bioceramics

CaSiO3 (CS) ceramics have been regarded as a potential bioactive material for bone regeneration. Mg2SiO4 (M2S) ceramic has been reported as a novel bioceramic with higher mechanical properties and good biocompatibility recently. beta-Ca-2(PO4)(2) (beta-TCP) ceramic is a well-known bioactive and degradable material for bone repair. The aim of this study is to investigate and compare the effect of three bioceramics with different chemical composition on the in vitro degradation, apatite-forming ability in simulated body fluid (SBF) and cytocompatibility. The degradation was evaluated through the activation energy of Si or P ion released from ceramics and the weight loss of the ceramics in Tris-HCl buffer solution. Formation of bone-like apatite on different bioceramic surfaces was investigated in SBF. The presence of bone-like apatite layer on the material surface after soaking in SBF was demonstrated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM). The effect of ionic products from the three kinds of material dissolution on osteoblast-like cell proliferation was investigated. The results showed that the degradation rate of CS was much faster than that of beta-TCP and M2S ceramics. Apatite formation occurred on the CS ceramics quickly. However, it was less likely to occur on the surfaces of beta-TCP and M2S ceramics. The ionic products from extracts of CS and M2S could stimulate osteoblast-like cell proliferation at certain concentration range throughout the 6-day culture period.