Enhanced corrosion resistance and bioactivity of Mg alloy modified by Zn-doped nanowhisker hydroxyapatite coatings.

In this work, Zn is doped into a hydroxyapatite coating on the surface of ZK60 magnesium alloys using a one-pot hydrothermal method to obtain a corrosion-resistant implant with abilities of osteogenic differentiation and bacterial inhibition. With the addition of Zn, the morphology changes with a nanowhisker structure appearing on the coating. Electrochemical measurements show that the nanowhisker hydroxyapatite coating provides a high corrosion resistance. Compared with hydroxyapatite coating, the nanowhisker coating not only effectively inhibits bacteria, but also promotes the adhesion and differentiation of rat bone marrow mesenchymal stem cells at appropriate Zn concentrations. In conclusion, a novel nanowhisker structure prepared by a single variable Zn doping can significantly improve the corrosion resistance and biological activity of hydroxyapatite coatings.