Bioinspired Vascular Stents with Microfluidic Electrospun Multilayer Coatings for Preventing in‐stent Restenosis

In-stent restenosis (ISR) is seriously affecting the long-term prognosis of vascular interventional therapy and leading to enormous medical burdens. Great efforts have been devoted to developing functional vascular stents with desired features and properties for effective ISR prevention. Here, a multifunctional bionic vascular stent with designed coatings prepared using microfluidic electrospinning technology is presented. Such stents are composed of biocompatible, drug-loaded methylacrylated gelatin-polyethylene glycol diacrylate (GelMA-PEGDA) and polycaprolactone composite nanofibers on 316L stainless steel stents by an easy-to-operate step-by-step spraying method. Benefitting from the addition of polydopamine during the fabrications, the drug-loaded composite nanofibers can adhere well to both the stent and the vascular wall. Furthermore, as the inner fibrous layer of the stent contacting the lumen is equipped with heparin-vascular endothelial growth factor (Hep-VEGF), it plays an anticoagulation role and promotes the growth of endothelial cells; while the outer layer contacts the vascular wall and releases rapamycin slowly, which can restrain smooth muscle proliferation. By implanting this into the rabbit carotid artery, the multi-functional bionic demonstrates that the vascular stent can achieve good anti-thrombosis and in-stent restenosis effects, which indicates its potential values in vascular intervention and other biomedical fields.