Stent coating for eluting medication

摘要

A vascular stent comprising a drug-eluting outer layer of a porous sputtered columnar metal having each column capped with a biocompatible carbon-containing material is described. This is done by placing the stent over a close-fitting mandrel and rotating the assembly in a sputter flux. The result is a coating that is evenly distributed over the outward-facing side of the stent's wire mesh while preventing the sputtered columnar coating from reaching the inward facing side where a smooth hemocompatible surface is required. The stent is then removed from the mandrel, exposing all surfaces, and finally coated with a layer of carbon such as amorphous carbon or diamond-like carbon. The carbonaceous coating enhances biocompatibility without preventing elutriation of a therapeutic drug provided in the porosity formed between the columnar structures. The result is a stent that is adapted to both the hemodynamic and the immune response requirements of its vascular environment.