Development of magnesium calcium phosphate biocement for bone regeneration

Abstract

Magnesium calcium phosphate biocement (MCPB) with rapid-setting characteristics was fabricated by using the mixed powders of magnesium oxide (MgO) and calcium dihydrogen phosphate (Ca(H 2 PO 4 ) 2 ·H 2 O). The results revealed that the MCPB hardened after mixing the powders with water for about 7 min, and the compressive strength reached 43 MPa after setting for 1 h, indicating that the MCPB had a short setting time and high initial mechanical strength. After the acid–base reaction of MCPB containing MgO and Ca(H 2 PO 4 ) 2 ·H 2 O in a molar ratio of 2 : 1, the final hydrated products were Mg 3 (PO 4 ) 2 and Ca 3 (PO 4 ) 2 . The MCPB was degradable in Tris–HCl solution and the degradation ratio was obviously higher than calcium phosphate biocement (CPB) because of its fast dissolution. The attachment and proliferation of the MG 63 cells on the MCPB were significantly enhanced in comparison with CPB, and the alkaline phosphatase activity of MG 63 cells on the MCPB was significantly higher than on the CPB at 7 and 14 days. The MG 63 cells with normal phenotype spread well on the MCPB surfaces, and were attached in close proximity to the substrate, as seen by scanning electron microscopy (SEM). The results demonstrated that the MCPB had a good ability to support cell attachment, proliferation and differentiation, and exhibited good cytocompatibility.