In vitro endothelialization of PTFE vascular grafts: A comparison of various substrates, cell densities, and incubation times

To establish the optimal conditions for achieving endothelial cell coverage of the luminal surfaces of small-caliber vascular grafts in vitro, the att achment of endothelial cells (ECs) cultured from human umbilical veins to p olytetrafluoroethylene (PTFE) grafts was studied. Cell attachment and sprea ding were compared after PTFE grafts were (a) precoated with fibronectin (H FN), type I collagen, type IV collagen, plasma and fibrin with or without t hrombin, singly or in combination; (b) seeded with cell densities varying f rom 0.5 x 10(5) to 6 x 10(5) cells/cm(2); and (c) incubated at 30, 60, or 9 0 min. Cell coverage and spreading were assessed by means of scanning elect ron microscopy. Quantification of graft surface coverage was performed with computer-assisted image analysis. To determine optimal conditions of endot helialization among the 189 treatment combinations, analysis of variance wa s used. We conclude that a virtually confluent cell monolayer can be establ ished on small-caliber PTFE grafts when precoated with fibrin glue or plasm a, seeded with cell densities greater than or equal to 4 x 10(5) cells/cm(2 ), and incubated for 60 min. These parameters are compatible with an operat ing room vascular procedure.