Fabrication and controlled release of electrosprayed ReoPro-loaded metal surface for vascular stent

Abstract

Metal stents have been very effective medical devices for coronary artery disease. On the other hand, hyperplasia proliferation of smooth muscle cells and late thrombus formation are the main causes of stent failure. To solve the problem, an anti-platelet/anti-proliferative drug, ReoRro, was used as a target drug for a drug-eluting stent (DES). An emulsion consisting of poly(lactic-co-glycolic acid) (PLGA), ReoRro, and poly(vinyl alcohol) (PVA) was electrosprayed on the stainless steel (SS) specimen. Three specimens were tested: bare-metal SS, PLGA-coated SS, and ReoRro-loaded SS. The surface morphology of polymer/ReoRro layer was smooth and the thickness was approximately 6 mu m. When different formulations of emulsion solutions were examined with various amounts of PVA (1, 5, 10%) or ReoRro (10, 20, 30%), the release profiles were affected significantly by the two factors. More PVA content and higher ReoPro concentration could accelerate the drug release in the given time period. Platelet adhesion and smooth muscle cell (SMC) growth were suppressed significantly in the ReoPro-loaded specimens. This indicates that hydrophilic ReoPro release can be controlled in the hydrophobic PLGA-based release system and the released ReoRro can be effective in suppressing platelet adhesion and SMC overgrowth for vascular stents.