Abstract:Mg-based alloys received significant attention for temporary implant applications while, their applications have been limited by high degradation rate. Therefore, silver-zeolite doped hydroxyapatite (Ag-Zeo-HAp) coating was synthesized on TiO₂-coated Mg alloy by physical vapour deposition (PVD) assisted electrodeposition technique to decrease the degradation rate of Mg alloy. X-ray diffraction (XRD) analysis and field emission scanning electron microscopy (FE-SEM) images showed the formation of a uniform and compact layer of Ag-Zeo-HAp with a thickness of 15 μm on the TiO₂ film with a thickness of 1 μm. The potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) tests indicated that corrosion resistance of Mg-Ca alloy was considerably increased by the Ag-Zeo-HAp coating. The bioactivity test in the simulated body fluid (SBF) solution showed that a dense and homogeneous bonelike apatite layer was formed on the Ag-Zeo-HAp surface after 14 d. Investigation of antibacterial activity via disk diffusion and spread plate methods showed that the Ag-Zeo-HAp coating had a significantly larger inhibition zone (3.86 mm) towards Escherichia coli (E. coli) compared with the TiO₂-coated Mg alloy (2.61 mm). The Ag-Zeo-HAp coating showed high antibacterial performance, good bioactivity, and high corrosion resistance which make it a perfect coating material for biomedical applications.

Key words: magnesium alloy; zeolite; coating; bioactivity; corrosion behavior; antibacterial activity