Fibroin reinforced, strontium-doped calcium phosphate silicate cements for bone tissue engineering applications

Calcium phosphate silicate cements (CPSCs) have been developed to overcome problems like high acidity due to presence of brushite and high temperatures evolving as polymethyl methacrylate (PMMA) cements cure at surgery site. However, CPSCs with good handling and injectability have not been successfully produced. Here, we aimed to develop a biocompatible and osteoconductive bone cement composed of strontium (Sr)-doped tri-calcium silicates (C 3 S), monocalcium monophosphate and silk fibroin (SF). C 3 S powders were mixed with monocalcium monophosphate, and SF to obtain injectable CPSC. Physical, mechanical and biological characterization studies revealed that SF presence minimized alkalinity, increased rate of weight loss, porosity and elasticity but decreased maximum yield strength. The i n vitro cell culture studies showed that all CPSCs were biocompatible. CPSC-Sr2-2% SF group performed the best in terms of osteogenic differentiation. These results suggest that CPSCs hold promise as bone cement however, in vivo studies should be conducted. Graphical abstract