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 attachment of endothelial cells (ECs) cultured from human umbilical veins to polytetrafluoroethylene (PTFE) grafts was studied. Cell attachment and spreading were compared after PTFE grafts were (a) precoated with fibronectin (HFN), type I collagen, type IV collagen, plasma and fibrin with or without thrombin, singly or in combination; (b) seeded with cell densities varying from 0.5 x 10(5) to 6 x 10(5) cells/cm2; and (c) incubated at 30, 60, or 90 min. Cell coverage and spreading were assessed by means of scanning electron microscopy. Quantification of graft surface coverage was performed with computer-assisted image analysis. To determine optimal conditions of endothelialization among the 189 treatment combinations, analysis of variance was used. We conclude that a virtually confluent cell monolayer can be established on small-caliber PTFE grafts when precoated with fibrin glue or plasma, seeded with cell densities >/=4 x 10(5) cells/cm2, and incubated for 60 min. These parameters are compatible with an operating room vascular procedure.