Preparation and preliminary cytocompatibility of magnesium doped apatite cement with degradability for bone regeneration

In the present study, we fabricated magnesium doped apatite cement (md-AC) with rapid self-setting characteristic by adding the mixed powders of magnesium oxide and calcium dihydrogen phosphate (MO–CDP) into hydroxyapatite cement (HAC). The results revealed that the md-AC with 50 wt% MO–CDP could set within 6 min and the compression strength could reach 51 MPa after setting for 1 h, indicating that the md-AC had highly initial mechanical strength. The degradability of the md-AC in Tris–HCl solution increased with the increase of MO–CDP amount, and the weight loss ratio of md-AC with 50 wt% MO–CDP was 57.5 wt% after soaked for 12 weeks. Newly flake-like apatite could be deposited on the md-AC surfaces after soaked in simulated body fluid (SBF) for 7 days. Cell proliferation ratio of MG63 cells on md-AC was obviously higher than that of HAC on days 4 and 7. The cells with normal phenotype spread well on the md-AC surfaces and attached intimately with the substrate, and alkaline phosphatase (ALP) activity of the cells on md-AC significantly improved compared with HAC on day 7. The results demonstrate that the md-AC has a good ability to support cell proliferation and differentiation, and indicate a good cytocompatibility.