Late endothelial progenitor cell-capture stents with CD146 antibody and nanostructure reduce in-stent restenosis and thrombosis.

The restoration of damaged endothelium is promising to reduce side effects, including restenosis and thrombosis, in the stent treatment for vascular diseases. Current technologies based on drug delivery for these complications still do not satisfy patients due to invariant recurrence rate. Recently, even if one approach was applied to clinical trial to develop the firstly commercialized stent employing circulating endothelial progenitor cells (EPCs) in blood vessels, it resulted in failure in clinical trial. Based on instruction of the failed case, we designed an advanced EPC-capture stent covered with anti-CD146 antibody (Ab) immobilized silicone nanofilament (SiNf) for the highly efficient and specific capture of not early but late stage of EPCs. In vitro cell capture test demonstrates enhanced capture efficiency and adhesion morphology of late EPCs on the modified substrate. The modified substrates could capture 8 times more late EPCs and even 3 times more mesenchymal stem cells (MSCs) as compared to unmodified one. A porcine model with high similarity to human reproduced in vivo results ideally translated from in vitro cell capture results. As restenosis indicators, lumen area, neointimal rate and stenosis area for modified stents were reduced at the range of 30-60% as compared to those for bare metal stent (BMS). Fibrin score indicating thrombosis was lowered less than half as comparing to that on BMS. These inspiring results are attributed to ~2-fold increased endothelial coverage, determined by immuno-histological staining. Taken together, the CD146 Ab-armed nanofilamentous stent could show great performance in the reduction of thrombosis and restenosis through re-endothelialization due to highly efficient specific cell capture. STATEMENT OF SIGNIFICANCE: Stents have been developed from simple metal stents to functionalized stents for past decades. However, they have still risks to relapse the occlusion in stented arteries. In this paper, we describe the fabrication and optimization of cell capturing stents to maximize the effective re-endothelialization through the serial coating of silicone nanofilaments and anti-CD146 antibody. The nanofilaments increase the amount of coated antibodies and provide the anchoring points of circulating angiogenic cells for strong focal adhesion. We demonstrate high immobilizing ability of circulating angiogenic cells (endotheliali progenitor cells and mesenchymal stem cells) in vitro under similar shear stress to coronary arteries (15 dyne/cm2). Also, we show accelerating re-endothelialization and the efficient prevention of restenosis in porcine coronary arteries in vivo.