Fucoidan-based coating on magnesium alloy improves the hemocompatibility and pro-endothelialization potential for vascular stent application

Biodegradable magnesium alloy stents have great application potential in the treatment of cardiovascular diseases. However, bare magnesium alloy stents are still limited by some problems such as too fast degradation, poor hemocompatibility, and inability to regulate the behaviors of vascular cells in clinical applications. Surface modifications are highly requested to improve the corrosion resistance and biocompatibility of magnesium alloy stents. Herein, a fucoidan-based coating consisting of MgF2 layer, polydopamine (PDA) and fucoidan was constructed on Mg-Zn-Y-Nd (ZE21B) alloy to improve its corrosion resistance, hemocompatibility and rapid endothelialization for vascular stent application. Compared to bare ZE21B alloy, the modified ZE21B alloy exhibited better corrosion resistance and hemocompatibility. More importantly, the endothelial cells (ECs) and smooth muscle cells (SMCs) exhibited a distinct dose-dependent behaviors towards the fucoidan grafting density. The relatively low fucoidan grafting density promoted the proliferation, spreading and migration of ECs, but suppressed these behaviors of SMCs. The results of in vivo implantation experiments indicated that the fucoidan-based coating modified ZE21B alloy can inhibit intimal hyperplasia, relieve tissue inflammation, and promote the rapid endothelialization. Thus, the fucoidan-based coating provides a simple and effective strategy to develop novel magnesium alloy stents with improved corrosion resistance, good hemocompatibility and pro-endothelialization potential.