A multifunctional coating with modified calcium phosphate/chitosan for biodegradable magnesium alloys of implants

Magnesium (Mg) alloys with outstanding biocompatibility and mechanical properties are extensively used in medical implantation. However, the rapid degradation and potential cytotoxicity in the physiological environment limit their further clinical applications. In this study, we prepared a calcium phosphate/chitosan (CaP/CTS) coating by chemical conversion and dip-coating methods to increase the corrosion resistance, biocompatibility and antibacterial property of the Mg alloy. The surface morphology, electrochemical and immersion tests signified that the CaP/CTS coating showed a significantly improved corrosion resistance because the chitosan efficiently filled the cracks and reduced the porosity of the CaP coating. In vitro investigation of cell response and contact angle experiments confirmed that the composite coating had excellent cytocompatibility and hydrophilicity. In addition, the composite coating demonstrated a prominent antibacterial ability of 95.9 +/- 0.4% against Escherichia coli (E.coli). The strengthened corrosion resistance, biocompatibility and antibacterial property of the CaP/CTS coating deposited Mg alloy make it an up-and-coming prospect in the field of implants.