Bone defects occurring for various reasons can lead to deformities and dysfunctions of the human body. Considering the need for clinical applications, it is essential for bone regeneration to exploit a scaffold with bioactive bone cement. In this study, we fabricated bioactive magnesium phosphate bone cement (BMPC) at room temperature; then, it was set at to °Cand 100% humidity for 2 h. The process was as follows: Simulating a clinical environment, magnesium oxide (MgO) was formed by calcining basic magnesium carbonate (Mg2(OH)2CO3). MgO, potassium dihydrogen phosphate (KH2PO4) and carboxymethyl chitosan (C20H37N3O14, CMC) were mixed to form magnesium phosphate bone cement (MPC); then, monocalcium phosphate (Ca(H2PO4)2) was added to neutralize the alkaline product after MPC hydration to fabricate bioactive magnesium phosphate bone cement (BMPC). The influence of the doped content of Ca(H2PO4)2 on the properties of bone cement was discussed. The results showed that Ca(H2PO4)2 and CMC can adjust the setting time of bone cement to between 8 and 25 min. The compressive strength increased first and then decreased. After 48 h without additional pressure, the compressive strength reached the maximum value, which was about 38.6 MPa. Ca(H2PO4)2 and CMC can play a synergistic role in regulating the properties of BMPC. The BMPC was degradable in the simulated body fluid (SBF). The results of the 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 requirements. BMPC is a promising orthopedic material and is suitable for repairing bone defects.

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.