physicochemical properties and biocompatibility of silica doped β-tricalcium phosphate for bone cement

Background/purpose: β-Tricalcium phosphate (β-TCP) is an osteoconductive material. Earlier reports revealed that silica plays an important role in bone mineralization, and its incorporation would enhance the biocompatibility of implants. Materials and methods: In this study, silica doping at various concentrations (0 wt.%, 10 wt.%, 20 wt.%, and 30 wt.%) was performed. Si-â-TCP was obtained upon calcining the as-prepared powders at 1400°C. To check its effectiveness, different Si-â-TCP samples were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of bonelike apatite, the diametral tensile strength, ions released, and weight loss of composites were considered before and after immersion in simulated body fluid. We also examined the behavior of human dental pulp cells (hDPCs) cultured on these materials. Results: The results showed that the apatite deposition ability of the β-TCP was enhanced as the Si content was increased. For composites with >20% Si content, the apatite layer covered the samples. At the end of the immersion point, weight losses of 52%, 45%, 33%, and 26% were observed for the β-TCP containing 0%, 10%, 20%, and 30% Si, respectively. In vitro cell experiments showed that the Si-rich cement promotes hDPC proliferation and differentiation. However, when the Si content in the cement is >20%, the amount of cells and osteogenesis protein of hDPCs were stimulated by Si released from Si-β-TCP. Conclusion: The degradation of β-TCP and osteogenesis of Si give us a strong reason to believe that these Si-based cements may prove to be promising bone repair materials.