Opportunities and prospects for the use of porous silicon to create a polymer-free drug coating on intravascular stents

In search of a container material for drugs placement to create the polymer-free stents with drug coatings (polymer-free drug-eluting stents), an analysis of the known literature data is carried out. It is shown that one of the promising materials for this purpose is porous silicon with mesoporous structure (transverse pore diameter 2–50 nm), which has high biocompatibility and biodegradation ability. The basic requirements to the characteristics of porous silicon coating on metal intravascular stents are formulated. The results of experimental studies, including those carried out by the authors of this article, show the possibility of applying a unbroken silicon coating up to 0.6 µm thick to the stents using magnetron sputtering or plasma-immersion ion implantation and deposition (PIII@D) methods. These methods provide high adhesion of the coating to the stent material and allow the coating to be applied to the outer and inner surface of the stent.