In Vitro Behavior and Surface Morphology of Modified 316L Stainless Steel Stents

When compared with conventional bare metal stents, such as 316L stainless steel, the introduction of drug-eluting stents can promote reduction in the incidence of in-stent restenosis. However, the chemical discrepancy between the metallic stent and the polymeric material that acts as the reservoir for the drug is responsible for some problems during the cardiovascular surgery. Besides the research work aiming at the development of new bulk alloys for stent production, focus as been also directed to the surface modification of these devices. However, the use of functional graded coatings (FGC), i.e., coatings with a gradient of chemical composition between the substrate and the outmost layer, has never been reported in devices for cardiovascular surgery.