1. ¹Regenerative Medicine Institute, National Centre for Biomedical Science Engineering, National University of Ireland, Galway, Ireland
2. ²Department of Cardiology, University College Hospital Galway, National University of Ireland, Galway, Ireland
3. ³Department of Medicine, University College Hospital Galway, National University of Ireland, Galway, Ireland

Correspondence: Timothy O'Brien, Department of Medicine, Clinical Sciences Institute, University College Hospital, Galway, Ireland. E-mail: timothy.obrien@nuigalway.ie

Received 11 May 2007; Accepted 2 July 2008; Published online 19 August 2008.

Abstract

Drug-eluting stents for coronary artery disease results in inhibition of smooth muscle cell (SMC) and endothelial cells which may increase the risk of stent thrombosis. In this study, we attempted to enhance re-endothelialization of deployed stents while simultaneously inhibiting intimal hyperplasia by overexpression of endothelial nitric oxide synthase (eNOS) delivery in the vasculature using an adenovirus gene–eluting stent. Re-endothelialization was significantly greater in vessels obtained from normocholesterolemic animals at day 14 (85.34% 7.38 versus 62.66% 10.49; P < 0.05) and day 28 (91.1% 10 versus 63.1% 22; P < 0.05) and hypercholesterolemic animals (96.97% 3.2 versus 28.33% 38.76; P < 0.05) at day 28 with AdeNOS-eluting stents. At day 28, there was a significant increase in the lumen size [AdeNOS 2.73 mm² 1.18, AdGal 0.98 mm² 0.98, phosphorylcholine (PC) 1.87 mm² 1.18; P < 0.05], and a significant reduction in neointimal formation (AdeNOS 2.32 mm² 1.13, AdGal 3.73 mm² 0.95, PC 3.2 mm² 0.94; P < 0.05), and percent restenosis (AdeNOS 45.23 20.81, AdGal 79.6 20.31, PC 70.16 22.2; P < 0.05) in AdeNOS-stented vessels in comparison with controls from hypercholesterolemic animals, assessed by morphometry and quantitative coronary angiography (AdeNOS 15.95% 7.63, AdGal 56.9% 38.6, PC 58 34.6; P < 0.05). Stent-based delivery of AdeNOS results in enhanced endothelial regeneration and reduction in neointimal formation as compared with controls. This seems to be a promising treatment strategy for preventing in-stent restenosis (ISR) while simultaneously reducing the risk of stent thrombosis.