A self-healing coating with embedding of polyphenols on magnesium: Towards enhanced corrosion protection for biodegradable vascular implants

Biodegradable magnesium-based vascular stent has become a research hotspot in the field of interventional medical engineering. However, the rapid degradation rate and inadequate biocompatibility of magnesium-based vascular stents often lead to implant failure in biomedical applications. It is of great research significance to slow down the degradation rate of magnesium-based stents and impart them with multifunctional bioactivity through surface modification. In this study, a self-healing coating with embedding of polyphenols is developed to create on the surface of magnesium towards corrosion protection and biocompatibility. By controlling and studying the self-healing responsiveness of the coating, the corrosion resistance under vascular implantation conditions is investigated. The embedding of polyphenols endows the interface a self-healing capability, which might be drawn as the chelation between phenol/metal ions and the formation of intermolecular connection between each of the chelating units which ultimately cause enhanced corrosion protection. Furthermore, the evaluation of biocompatibility indicates that the polyphenol-loaded polymer layer shows good biocompatibility, which is beneficial for the repair of the vascular microenvironment. These results suggest significant potential applications of this composite coating in magnesium-based vascular stents.