Corrosion resistance and cell compatibility in vitro of Chinese herbal extract coating on magnesium

To enhance the corrosion resistance and biological activity of pure Mg, an ultrasonic micro-arc oxidation (UMAO)/chitosan (CS)/icariin (IC) coating was prepared on a pure Mg substrate using a combination of UMAO with electrophoretic deposition (EPD). The coatings were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), contact-angle meter, and Fourier transform infrared (FTIR) spectroscopy. The corrosion resistance of various samples was evaluated via potentiodynamic polarization and electrochemical impedance spectroscopy in a simulated body fluid (SBF) solution. The cytocompatibility of the various coatings was investigated. The results demonstrated that the UMAO/CS/IC coating exhibited the best corrosion resistance compared to those of bare magnesium, UMAO, and UMAO/CS coating. Osteoblastic adhesion and proliferation were enhanced by the Chinese herbal extract coating. The combination of corrosion protection and cell compatibility reaction suggests that this coating is very promising for application in orthopedic implants. Keywords: Pure magnesium, Chinese herbal extract coating, Corrosion resistance, Cell compatibility