Construction of ZnONRs-PDA/PMPC nanocomposites on the surface of magnesium alloy with enhanced corrosion resistance and antibacterial performances

Magnesium alloy (MgA) with satisfactory biodegradability and excellent mechanical properties has been widely applied in new degradable medical implant materials, especially cardiovascular scaffold materials. However, fast degradation and limited biological activities always restrict the application of MgA. Herein, we have constructed multi-functional inorganic-organic nanocomposites (ZnONRs-PDA/PMPC) onto the surface of micro-arc oxidation pretreated magnesium alloys (MgA-MgO), where ZnO nanorods (ZnONRs) were grown by a microwave-assisted hydrothermal method, and polydopamine/poly(2-methacryloyloxyethyl phosphorylcholine) (PDA/PMPC) films were prepared by a co-deposition strategy. The morphology and composition of MgA-MgO-ZnONRs-PDA/PMPC were characterized by field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), and so on. The MgA-MgO-ZnONRs-PDA/PMPC exhibited good hydrophilic property with a water contact angle of 37.4° and improved the corrosion resistance performance with decreasing the corrosion current density (icorr) by 3 orders of magnitude compared with pristine MgA. Moreover, the MgA-MgO-ZnONRs-PDA/PMPC showed good anti-platelet adhesion performance and excellent antibacterial activities with bactericidal rates of 98.1% against S. aureus and 96.2% against E. coli. This work provides an easy and effective method to fabricate a multi-functional nanocomposite with excellent corrosion resistance and biological activities that would facilitate the potential applications of MgA in biomedical fields.