Surface modification applied to magnesium alloys could greatly enhance anti-corrosion. This is also expected to maintain the high strength of magnesium alloy to maintain vascular support after stent placement. When endothelial cells are injured by the oxidative stress, smooth muscle cells will also crawl into the intimal layers with compensation, which leads to serious vascular stenosis. Much literature indicated that magnesium alloy has a lower neointimal area than stainless steels. This phenomenon helps endothelial remodeling. During the degrading time, the polymer coating can be used as drug delivery and a corrosion barrier for magnesium stents. After PCI, wounds caused by the stenting are likely to trigger immune reactions - platelet activation. Polyphenol-loaded PLGA layers possess the anti-inflammatory effect for the stents coating. It is expected to be controlled in the early stage by the technologies and concepts we applied in smart biodegradable metallic cardiovascular stents.

A small-molecule eluting coating (PLGA(GA)) is designed using a sandwich structure with a GA layer enclosed  PLGA layers, which increases the anticorrosion of magnesium alloys and prevents the burst release of GA. It was found that the coating enhanced corrosion resistance 2000 times (at a current density of (µA/cm 2 )) more than ZK60. The released GA molecules from coating inhibit oxidation by capturing free radicals and selectively promote the proliferation of endothelial cells and inhibit SMC growth. Within the properties of delayed wound closure in smooth muscle cells, while showing potential migration in endothelial cells, the PLGA(GA) thus has great potential to develop functional vascular stents that prevent late-stent restenosis.

Taiwanese can install nearly 40,000 cardiovascular stents per year, and the population of users is increasing year by year with the aging society. Due to the epidemic situation this year, medical materials made in Taiwan have received international attention, the development of stents will have the advantages of domestic demand and export. Taiwanese mature machinery processing and material chemical industry, coupled with increasingly mature medical regulations, clinical inspection, and the pharmaceutical industry. If the upstream and downstream of the industries in small scale and highly overlapping technologies can be well integrated, the development of the high-end medical industry can be used to upgrade our traditional industry.