PLGA and Mg(OH)2 Composite Coatings on Zinc Alloy for Improving Degradation Resistance and Cell Compatibility

To address the issue of burst release of Zn2+ ions in the early degradation stage of degradable zinc alloys and enhance their cellular activity, a composite coating consisting of PLGA and Mg(OH)2 was prepared on the surface of Zn alloys. The incorporation of Mg(OH)2 serves two purposes: on one hand, it regulates the pH value; on the other hand, it releases Mg2+ ions to improve cytocompatibility. A series of tests, including electrochemical corrosion testing, ion dissolution testing, sample morphology observation, and cytotoxicity testing, was conducted to investigate the morphology, degradation process, ion release, and cytocompatibility of the coating. The results demonstrate that the composite coating can effectively reduce the release of Zn2+ ions, regulate the pH value after coating degradation, and control the release of Mg2+ ions, thereby significantly reducing the toxicity to osteoblasts and improving its biocompatibility.