Study on injectable and degradable cement of calcium sulphate and calcium phosphate for bone repair

Injectable calcium sulphate/phosphate cement (CSPC) with degradable characteristic was developed by introduction of calcium sulphate (CS) into calcium phosphate cement (CPC). The setting time, compressive strength, composition, degradation, cells and tissue responses to the CSPC were investigated. The results show that the injectable CSPC with optimum L/P ratio exhibited good injectability, and had suitable setting time and mechanical properties. Furthermore, the CSPC had good degradability and its degradation significantly faster than that of CPC in Tris-HCl solution. Cell culture results indicate that CSPC was biocompatible and could support MG63 cell attachment and proliferation. To investigate the in vivo biocompatibility and osteogenesis, the CSPC were implanted in the bone defects of rabbits. Histological evaluation shows that the introduction of CS into CPC enhanced the efficiency of new bone formation, and CSPC exhibited good biocompatibility, degradability and osteoconductivity with host bone in vivo. It can be concluded that the injectable CSPC had a significant clinical advantage over CPC, and might have potential to be applied in orthopedic, reconstructive and maxillofacial surgery, especially for minimally invasive techniques.