Influence of monocalcium phosphate on the properties of bioactive magnesium phosphate bone cement

Abstract Background: The bone defects caused by different reasons led to deformity and dysfunction of human body. Considering the need for clinical application, it was essential for bone regeneration to exploit a scaffold with bioactive bone cement. In this paper, we fabricated bioactive magnesium phosphate bone cement (BMPC) at room temperature, then it was set at 37℃ and 100% humidity for 2h. Methods: The process was as follows. MgO was formed by calcining Mg2(OH)2CO3, MgO, KH2PO4 and carboxymethyl chitosan were mixed to form magnesium phosphate bone cement(MPC), then Ca(H2PO4)2 was added to neutralize alkaline product after MPC hydration to fabricate bioactive magnesium phosphate bone cement (BMPC). The influence of doped content of Ca(H2PO4)2 on the properties of bone cement was discussed. Results: The results showed that Ca(H2PO4)2 and carboxymethyl chitosan can adjust the setting time of bone cement within the scope of 8 minute and 25 minute. The compressive strength increased first and then decreased. After 48h without additional pressure, the compressive strength reached the maximum value, so it was about of 38.6 MPa. Ca(H2PO4)2 and carboxymethyl chitosan can play a synergistic role in regulating the BMPC properties. BMPC was degradable in the simulated body fluid (SBF). The results of cytotoxicity experiment and laser confocal microscopy experiment indicated that BMPC fabricated at room temperature had better biocompatibility and degradability, which was more consistent with clinical operation requirement.Conclusions: BMPC can be used as a promising orthopedic material, and it can meet with the needs for repairing bone defects.