Adaptive PEO-based biointerfaces on magnesium alloys: Smart surfaces for localized drug delivery and biointegration

Background Growing clinical interest in fully degradable implant materials that eliminate secondary removal procedures has positioned magnesium and its alloys at the forefront of biomaterials research due to their biodegradability, favorable mechanical properties, and biocompatibility. However, rapid corrosion, limited bioactivity, and insufficient antibacterial performance remain major obstacles to their clinical translation. Methods This comprehensive review systematically analyzes recent literature on drug-loaded plasma electrolytic oxidation (PEO) coatings applied to magnesium substrates, with particular focus on coating fabrication strategies, drug incorporation approaches, release behavior, and in-vitro and in-vivo performance reported using electrochemical, surface, and biological characterization techniques. Significant findings The reviewed studies demonstrate that PEO-based coatings significantly improve corrosion resistance and tribological performance while serving as effective platforms for localized drug delivery. Incorporation of antibiotics, anticancer agents, anti-inflammatory drugs, and bisphosphonates enables controlled release, enhanced osseointegration, improved biocompatibility, and strong antibacterial activity. Overall, drug-loaded PEO coatings effectively regulate magnesium degradation and function as multifunctional biointerfaces, highlighting their strong potential for next-generation biodegradable implant applications.