Baicalin-based composite coating for achieving biological multifunctionality of vascular stents

Vascular stents are frequently used in interventional therapy for atherosclerotic arteries. Interventional treatment with bare metal stents and drug-eluting stents has significantly reduced mortality. Restenosis and late thrombus were also major safety concerns in stent implantation. Hyaluronic acid (HA), a multifunctional polymer, is commonly used for surface modification of biomaterials. However, its application in vascular stents still faces challenges, as it is susceptible to degradation by reactive oxygen species (ROS) and hyaluronidase (HAase), leading to the formation of pro-inflammatory small molecular fragments that can affect the stability and functionality of vascular stent coatings. Based on controllable oxidative stress, we propose and construct a multifunctional molecular composite coating using baicalin (BCL), achieving successful synergy between BCL and HA. The surface-fixed BCL in the coating resists ROS and HAase to prevent surface HA degradation, reducing macrophage transition to pro-inflammatory phenotypes and smooth muscle cell transition to synthetic phenotypes. Additionally, it protects endothelial cells in oxidative stress environments, promotes endothelialization, and reduces HAase expression levels in tissues to enhance tissue stability. Therefore, this study presents a promising biomedical surface modification method for vascular stents.