Preparation of ROS‐Responsive Exosome Coating of Nitinol Material for Making the Neurointerventional Stent

Abstract Nitinol (NiTi) alloy is an ideal material for preparing neurointerventional stents due to its excellent mechanical properties and biocompatibility. However, NiTi stents without surface‐specific functionalization cause a high rate of stent thrombosis and in‐stent restenosis after implantation. In ischemic stroke, exosomes have a role in regulating nervous system development, regeneration, vascular remodeling, and neuroinflammation. In this work, the effect of exosome coating on the biocompatibility of NiTi alloy is evaluated. NiTi alloy is successively immersed in relevant solution (sodium alginate, 3‐aminophenylboronic acid, distearoylphosphatidylethanolamine, and exosomes) to form ROS‐responsive exosome coated surfaces. In vitro experiments (platelets, endothelial cells, smooth muscle cells, and macrophages) and in vivo subcutaneous implantation experiments are performed to test coatings for biocompatibility. The results show that the modified NiTi alloy surface has high hydrophilicity, which has the functions of inhibiting platelet aggregation, promoting endothelialization, inhibiting smooth muscle cell migration, anti‐inflammatory, and good tissue biocompatibility. This study develops exosome neurointerventional stent coating as a bioactive drug via reactive oxygen species accumulation in lesions, thus targeting drug release, inhibiting intimal hyperplasia, and reducing inflammation and thrombosis.