Bioactive tetracalcium phosphate/magnesium phosphate composite bone cement for bone repair.

In order to acquire a tetracalcium phosphate/magnesium phosphate (TTCP/MPC) composite bone cement that combines the excellent bioactivity of TTCP and high mechanical strength of MPC, the cement was made and the compressive strength, phase composition of hardened cement, degradation in vitro, and tissue responses in vivo by implantation of TTCP/MPC in bone defect of rabbits were investigated. The results showed that TTCP/MPC was with a markedly better mechanical property than MPC. Moreover, compared with MPC, TTCP/MPC showed significantly delayed degradability in simulated body fluid. To investigate the in vivo biocompatibility and osteogenesis, the TTCP/MPC samples were implanted into bone defects in rabbits. Histological evaluation displayed that the introduction of TTCP into MPC enhanced the efficiency of new bone formation. TTCP/MPC also showed good biocompatibility, biodegradability and osteoconductivity with host bone in vivo. The results suggested that TTCP/MPC meets the basic requirements of bone tissue engineering, has an obvious clinical advantage over MPC and is promising to be applied in orthopedic, reconstructive and maxillofacial surgery.