Effect of PLGA+MAO composite coating on the degradation of magnesium alloy in vivo and in vitro

The rapid degradation rate of magnesium alloy affects its mechanical support as implant materials, which limits its application as medical implant materials. Therefore, it is of great significance to design a protective coating with low degradation rate and excellent biological activity. In this paper, a PLGA+MAO composite coating was prepared on a magnesium alloy. The long-period degradation behavior of PLGA+MAO coating in vivo and in vitro and the bone tissue growth were studied. The results have shown that the anti-corrosion performance of PLGA+MAO composite coating transcended that of MAO coating and uncoated Mg alloy both in vivo and in vitro. Obvious new bone growth was found around the PLGA+MAO coated implants in vivo. However, localized corrosion is still the main corrosion form once the PLGA+MAO coating is failed at some region, which could be an issue for the biocompatibility at the fast localized corrosion region and should be studied in the future.