Multi‐Functional S‐HA/ASTA NPs Coating on Biodegradable ZE21B Alloy for Cerebrovascular Applications

ABSTRACT Magnesium (Mg) and its alloys have attracted extensive attention of researchers in the field of cerebrovascular implants due to their good mechanical properties and biosafety. However, rapid degradation and delayed endothelialization pose challenges. To address these issues, this study introduces a multifunctional composite coating. For ZE21B Mg alloy stents, combining sulfonated hyaluronic acid (S‐HA) and astaxanthin (ASTA) nanoparticles. The coating includes a self‐assembled MgF 2 layer and an MgF 2 /polydopamine (PDA) layer incorporating S‐HA/ASTA nanoparticles. This multi‐layered structure aims to enhance corrosion resistance, promote endothelial cells (ECs) growth, reduce inflammation, improve blood compatibility, and neutralize reactive oxygen species. These improvements could significantly advance the use of Mg alloy stents in treating cerebrovascular disease. The S‐HA/ASTA NPs coating demonstrated superior ability to promote the increase in the corrosion resistance of ZE21B substrate, reduces its degradation rate, and maintains a contractile phenotype of smooth muscle cells. Additionally, it reduced M1 macrophage (MA) markers, promoted the M2 macrophage phenotype, and inhibited intracellular fibrosis. The results showed that the S‐HA/ASTA NPs coating has enhanced the corrosion resistance, biocompatibility, anti‐inflammation, anti‐hyperplasia, and anti‐coagulation of the Mg alloy stent. These findings present a promising and practical approach for surface modification of Mg‐based degradable cerebrovascular stents.