Electrochemical behaviour and cytocompatibility of nano-fluoridated apatite coating on biodegradable magnesium alloy by simple chemical conversion

Magnesium and its alloys have attracted great attention as biocompatible and degradable biomaterials recent years. But their corrosion rate has been proved to be too high, which limits their biomedical application greatly. In order to improve the corrosion resistance, nano-fluoridated apatite (FA) coating was prepared on ZK60 magnesium alloy by a simple chemical conversion method. The FA coating showed a needle-like morphology. The polarization curves and EIS plots indicated that the FA coating improved the corrosion potential by 125 mV and doubled the polarization resistance of the magnesium alloy, meanwhile decreasing the corrosion current by two orders of magnitude of the substrate in simulated body fluid. The MTT assay indicated good cytocompatibility of L-929 cells with the fluoridated apatite coated magnesium alloy.