RELEASE OF PDGF-BB AND BFGF BY HUMAN ENDOTHELIAL-CELLS SEEDED ON EXPANDED POLYTETRAFLUOROETHYLENE VASCULAR GRAFTS

Background. The majority of endothelial cell (EC) seeded graft failure s are due to anastomotic neointimal fibrous hyperplasia. We investigat ed the PDGF-BB and bFGF release in vitro by umbilical vein EC seeded o n precoated expanded polytetrafluoroethylene (ePTFE) prostheses. Mater ials. EC harvested from human umbilical veins were seeded into ePTFE ( 30 mu m internodal distance, 1 cm(2) in diameter) disks. ePTFE disks u ncoated or precoated with collagen type I, fibronectin, and Matrigel w ere used, and EC seeded into plastic wells coated as ePTFE disks or un coated plastic wells served as controls. Scanning electron microscopy study assessed EC coverage. The presence of bFGF and PDGF-BB in serum- free conditioned media from EC seeded into ePTFE grafts and EC seeded into wells was determined by the inhibition antibody-binding assay 72 h after seeding. Results. EC coverage was similar in uncoated and coat ed ePTFE grafts. The release of PDGF-BB and bFGF by EC seeded into ePT FE grafts was significantly higher than that observed in EC seeded int o plastic wells. The release of PDGF-BB and bFGF was independent from the various substrates used in the experiments in EC seeded into eithe r ePTFE grafts or plastic wells. Conclusions. Our findings pointed out that in seeded ePTFE grafts, anastomotic smooth muscle cell prolifera tion and intimal thickening could take place underneath an intact endo thelium because seeded EC may release several growth factors. (C) 1998 Academic Press.