Natural Fucoidan and Bioactive ACH ₁₁ Peptides Multilayer Coating on Biodegradable Magnesium Alloy for Potential Application in Vascular Stent

Magnesium alloy stents show cardiovascular promise due to strength and biodegradability , but rapid degradation and poor compatibility limit their clinical use.Herein, this study proposes a multilayer coating to enhance the corrosion resistance and biocompatibility of ZE21B alloy in vascular stent applications. The coating combines a MgF ₂ layer and a PDA layer, further functionalized with fucoidan and ACH ₁₁ peptides. Surface analysis indicated that the treated ZE21B alloy displayed a dense chemical conversion layer embedded with active biomolecules. The coated magnesium alloy possessed appropriate roughness, balanced wettability (around 56.1°), and a relatively low self‐corrosion current density (about 2.0 × 10 ⁻⁷ A cm ⁻² ). Blood compatibility tests indicated that the hemolysis rate and fibrinogen adsorption/denaturation levels of the coated magnesium alloy were approximately halved compared to untreated magnesium alloy, both meeting the requirements for blood‐contact medical devices. Additionally, the synergistic effect of fucoidan and ACH ₁₁ peptides significantly promoted endothelial cells (ECs) proliferation and nitric oxide release while inhibiting smooth muscle cells proliferation levels. This selective cellular response created a favorable environment for ECs regeneration. By substantially improving both corrosion resistance and vascular compatibility, this advanced coating system presents a groundbreaking approach to developing next‐generation biodegradable stents.