Human blood vessel-derived endothelial progenitors for endothelialization of small diameter vascular prosthesis.
BACKGROUND
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.


RESULTS
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 CD144high, 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.


CONCLUSIONS
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.
Ranjan
Amaresh K
AK
Stem Cells and Diabetes Section, National Center for Cell Science, Pune, India.
Kumar
Umesh
U
Hardikar
Ashutosh A
AA
Poddar
Pankaj
P
Nair
Prabha D
PD
Hardikar
Anandwardhan A
AA
D000327:Adsorption; D015703:Antigens, CD / Q000096:biosynthesis; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D001808:Blood Vessels / Q000473:pathology*; D015820:Cadherins / Q000096:biosynthesis; D002448:Cell Adhesion; D002454:Cell Differentiation; D004730:Endothelium, Vascular / Q000166:cytology / Q000473:pathology*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018613:Microscopy, Confocal / Q000379:methods; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis; D013234:Stem Cells / Q000166:cytology; D014841:von Willebrand Factor / Q000096:biosynthesis; D000099152:Cadherin 5
D015703:Antigens, CD; D015820:Cadherins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D014841:von Willebrand Factor; D000099152:Cadherin 5