A Novel Multifunctional Nanoscale Coating Based On Biomimetic Surface Engineering For Magnesium Alloy-based Stents Application

Magnesium(Mg)alloys,thanks to their biodegradability,biocompatibility andmechanical properties,show great promise as next-generation vascular stents for the invasive treatment for stenosis.However,the major limitations lie in the fast degradation of Mg matrix,as well as the high rate of in-stent restenosis post implantation.In this research we ultilized the mussel-inspired polydopamine(PDA)coating to enhance the corrosion resistance and biocompatibility of Mg alloys,as well as proposed a novel method to prepare PDA in organic solvent to to avoid adverse influence of reaction between Mg and the typical aqueous tris-HCl medium.The in vitro and in vivo experiments results showed that PDA significantly improved the anti-corrosion property and biocompatibility of Mg alloys.Meanwhile,as the current approach of applying drug-eluting coatings to stents(DES)is likely to cause thrombosis and other serious issues,in this study,we propose a new strategy of engineering a novel surface modification to promote cell adhesion and proliferation of vascular endothelial cells(ECs)while inhibiting those of smooth muscle cells(SMCs)by grafting EC-specific ligand REDV on an anti-fouling supramolecular hydrogel nanofiber film,thus to promote re-endothelialization and to decrease the rate of restenosis post stent implantation.And cell assays indicated the coating enhanced the competitive adhesion of ECs over SMCs.This research made a systematic study on corrosion resistance,biocompatibility and promoting re-endothelialization,which will not only provide in-depth investigations of the biointerfacial interactions and the involving mechanism of this coating material,but also offer a theoretical and technical basis for the development of promising vascular stents with greater performance.