In vitro and in vivo evaluation of the surface bioactivity of a calcium phosphate coated magnesium alloy

Magnesium has shown potential application as a bio-absorbable biomaterial, Such as for bone screws and plates. In order to improve the Surface bioactivity. a calcium phosphate was coated oil a magnesium alloy by a phosphating process (Ca-P coating). The Surface characterization showed that a porous and netlike CaGPO(4)center dot 2H(2)O layer with small amounts of Mg-21 and Zn-21 was formed oil the surface of the Mg alloy. Cells L929 showed significantly good adherence and significantly high growth rate and proliferation characteristics oil the Ca-P coated magnesium alloy (p < 0.05) in in-vitro cell experiments, demonstrating that the Surface cytocompatibility of magnesium was significantly improved by the Ca-P coating. In vivo implantations of the Ca-P coated and the naked alloy rods were carried Out to investigate the bone response at the early stage. Both routine pathological examination and immunohistochemical analysis demonstrated that the Ca-P coating provided magnesium with a significantly good Surface bioactivity (p < 0.05) and promoted early bone growth at the implant/bone interface. It Was suggested that the Ca-P coating might be all effective method to improve the surface bioactivity of magnesium alloy. (C) 2008 Elsevier Ltd. All rights reserved.