A vascular or endoluminal stent is adapted to be implanted in a vessel, duct or tract of a human body to maintain an open lumen. The stent includes a base layer of a biologically compatible metal. An intermediate metal particle layer of substantial greater radiopacity overlies the base layer, with particles bonded to the base layer and to each other to leave interstices therebetween as a repository for retaining and dispensing drugs or other agents for time release therefrom. The particles are composed primarily of a noble metal. Exposed surfaces of the particle layer are coated with ceramic-like iridium oxide or titanium nitrate, as a biocompatible material to inhibit irritation of tissue at the inner lining of the vessel when the stent is implanted.