Palliative therapy utilizing interventional stents, such as vascular stents, biliary stents, esophageal stents, and other stents, has been a prevalent clinical strategy for treating duct narrowing and partial blockage. However, stent restenosis after implantation usually significantly compromises therapeutic efficacy and patient safety. Clinically, vascular stent restenosis is primarily attributed to endothelial hyperplasia and coagulation, while the risk of biliary stent occlusion is heightened by bacterial adhesion and bile sludge accumulation. Similarly, granulation tissue hyperplasia leads to tracheal stent restenosis. To address these issues, surface modifications of stents are extensively adopted as effective strategies to reduce the probability of restenosis and extend their functional lifespan. Applying coatings is one of the technical routes involving a complex selection of materials, drug loading capacities, release rates, and other factors. This paper provides an extensive overview of state of the art drug-coated stents, addressing both challenges and future prospects in this domain. We aim to contribute positively to the ongoing development and potential clinical applications of drug-coated stents in interventional therapy.

Rough surfaces have been widely considered as negative factors affecting cavitation erosion resistance. However, this study presented the opposite result. Here, 316L stainless steel substrates and the arc-sprayed 316L stainless steel coatings were subjected to a specific grinding process that introduced scratches on the surfaces. The surface hardness values of these ground specimens were measured to evaluate the influence of the grinding-induced strain hardening. The cavitation erosion performance of the specimens was evaluated. The results showed that rough surfaces with scratches could enhance the cavitation erosion resistance, particularly at the early stage of cavitation erosion. The scratches had a greater effect on the cavitation erosion resistance of the coatings than on the substrates. Moreover, rough surfaces with initial surface scratches could extend the incubation period of the 316L stainless steel substrates due to the inhibition of the plastic deformation. The SEM observation showed that the scratch structure of the coating surface inhibited the growth of cracks and the propagation of cavitation pits. This study could also serve as a reference for investigating the cavitation erosion behaviors of materials with a particular surface feature.