Abstract 18078: Acceleration of High Quality Re-endothelialization by Capturing Circulatory Endothelial Progenitor Cells by Newly Developed Endothelial Growth Factor-bound Stent in Porcine Coronary Models
Background: Recently developed endothelial progenitor cells (EPCs) capturing stent, on which surface is coated with anti CD34 antibody, appears to accelerate tissue formation but does not reduce intimal hyperplasia. Because captured CD34-positive cells could contain various cell types beside EPCs and selective capture of EPCs was not so high. Cell surface receptors specifically expressed on endothelial lineage cells include not only CD34 but also vascular endothelial growth factor (VEGF) receptor and Tie. VEGF receptor is exclusively expressed on endothelial lineage cells. In this study, VEGF-bound stent was newly devised aiming at highly selective capturing of EPCs, and in vivo performances in early period of stenting were evaluated in porcine coronary models.
Methods and Results: Cobalt-chromium stents were coated with vinyl alcohol copolymer, followed by activation of surface hydroxyl group and subsequent protein binding were in-house prepared (n=39). At 2, 7, 14 and 42 days after stenting, coronary arteries were harvested. Histological analysis of neointimal tissue was evaluated by immunostaing (KDR, CD34, CD31, vWF, α-SMA). At 2 day-stenting of VEGF-bound stent, KDR -positive cells adhered on stent struts were observed. At one to two weeks, stent struts were covered by newly regenerated tissues which were immune-fluorescently positive for CD34 and KDR. At 2-weeks, scanning electron microscopic images showed that uniform monolayerd tissue formed on struts is morphologically resembled to native endothelium and exhibited continuous tissue appearance with native tissues. Neovascularization expression was not so high in the media and adventitia of VEGF-bound stent. Neointimal thicknesses at 2-weeks and 6 weeks stenting appeared to be low (67.9±27.3μ m at 2 week, 203±77.2μ m at 6 week).
Conclusion: VEGF-bound stent provides highly selective capturing of EPC followed by accelerated endothelial tissue formation about inside of stent and does not stimulate neovascularization about outside of stent. We suggest that rapid, high quality and intact endothelium tissue formation provides beneficial therapeutic option for cardiovascular stenting.
- © 2012 by American Heart Association, Inc.