Development of a novel dual PLGA and alginate coated drug-eluting stent for enhanced blood compatibility

Abstract

In this study, a dual-coated stent with two types of synthetic and natural polymers was reported for enhanced blood compatibility with anti-proliferation and anti-coagulation activities. A cobalt-chromium metal stent was coated with sirolimus-loaded poly(lactic-co-glycolic acid) (PLGA) via ultrasonic spray method and the PLGA-coated stent was then covered with heparin-loaded alginate hydrogel to reduce in-stent restenosis and blood coagulation. Surface morphology and thickness of the double-layer coated stent was characterized using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). In vitro degradation profile of cross-linked alginate hydrogel was examined related to the effect of CaCl2 concentration. Platelet adhesion and fibrinogen adsorption studies indicated that such dual-coated stent had a good blood compatibility to be used as a vascular drug-eluting stent. In vitro drug release studies and rat vascular smooth muscle cells (RVSMC) proliferation assay showed the effective anti-proliferation activity of smooth muscle cells on the dual-coated drug-eluting stents. These excellent results suggest that dual-coated stent with sirolimus-loaded PLGA and heparin-loaded alginate hydrogel had a great potential for the development of blood compatibility with effective inhibition of initial thrombosis and stenosis.