In vitro degradation and cytocompatibility of a silane/Mg(OH)2 composite coating on AZ31 alloy by spin coating

A new organic-inorganic composite coating was generated on AZ31 alloy surface with sol-gel method to improve the anti-corrosion performance and biocompatibility of AZ31 alloy in the physiological environment. The results of electrochemical impedance spectroscopy (EIS), potentiodynamic polarization , pH variations in modified-simulated body fluid (m-SBF) demonstrated that the silane/Mg(OH) 2 composite coating significantly enhanced the anti-corrosion ability and slowed down the degradation of AZ31 alloy under in vitro condition. Fourier-transform infrared spectroscopy (FTIR) showed that the major composition of in-situ formation layer was Mg(OH) 2 . The surface morphology , chemical and phase constitutions of the composite coating were detected using scanning electron microscopy (SEM). The results demonstrated that the composite coating was uniform and defect-free. X-ray diffraction analysis (XRD) was also employed to characterize the corrosion products of all specimens immersed in m-SBF after 30 days. MTT and ALP tests indicated that the composite coating greatly enhanced the cell proliferation and osteogenic differentiation of osteoblasts on the AZ31 alloy surface.