02401nas a2200193   4500008004100000245011600041210006900157260000800226300002600234490000600260520167800266100002401944700001701968700002701985700001902012700002102031700003102052856012402083       2009                        eng d00aHuman blood vessel-derived endothelial progenitors for endothelialization of small diameter vascular prosthesis0 aHuman blood vesselderived endothelial progenitors for endothelia  cNOV  aArticle Number: e77180 v43 aBackground: Coronary bypass graft failure as a result of acute thrombosis and intimal hyperplasia has been the major challenge in surgical procedures involving small-diameter vascular prosthesis. Coating synthetic grafts with patients' own endothelial cells has been suggested to improve the patency rate and overall success of bypass surgeries. 
Methodology/Principal Findings: We isolated endothelial progenitor cells (EPCs) from leftover pieces of human saphenous vein/mammary artery. We demonstrate that EPCs can be expanded to generate millions of cells under low-density culture conditions. Exposure to high-density conditions induces differentiation to endothelial cell phenotype. EPC-derived endothelial cells show expression of CD144(high), CD31, and vWF. We then assessed the ability of differentiated endothelial cells to adhere and grow on small diameter expanded polytetrafluoroethylene (ePTFE) tubings. Since ePTFE tubings are highly hydrophobic, we optimized protocols to introduce hydrophilic groups on luminal surface of ePTFE tubings. We demonstrate here a stepwise protocol that involves introduction of hydrophilic moieties and coating with defined ECM components that support adhesion of endothelial cells, but not of blood platelets. 
Conclusion/Significance: Our data confirms that endothelial progenitors obtained from adult human blood vessels can be expanded in vitro under xenoprotein-free conditions, for potential use in endothelialization of small diameter ePTFE grafts. These endothelialized grafts may represent a promising treatment strategy for improving the clinical outcome of small-caliber vascular grafts in cardiac bypass surgeries.1 aRanjan, Amaresh, K.1 aKumar, Umesh1 aHardikar, Ashutosh, A.1 aPoddar, Pankaj1 aNair, Prabha, D.1 aHardikar, Anandwardhan, A.  uhttps://library.ncl.res.in/content/human-blood-vessel-derived-endothelial-progenitors-endothelialization-small-diameter