Endothelial cell (EC) seeding significantly improves the blood compatibility of artificial surfaces. Although a coating consisting of albumin and heparin (alb-hep) is a suitable substrate for seeded ECs, binding of ECs to the substrate further improves when small amounts of fibronectin are present in the alb-hep coating. Alb-hep conjugate was immobilized on carbon dioxide gas plasma-treated polystyrene (PS-CO(2)), thereby significantly increasing the recalcification time of blood plasma exposed to this surface. Furthermore, surface-immobilized alb-hep conjugate inhibited exogenous thrombin. Heparin activity was reduced by adding fibronectin on top of a monolayer of alb-hep conjugate, but not by simultaneous coating of fibronectin and alb-hep conjugate. Coating of PS-CO(2) with alb-hep conjugate significantly decreased contact activation (FXII activation). The number of platelets deposited from blood plasma on PS-CO(2) coated with alb-hep conjugate was twice as high as on PS-CO(2) coated with albumin. Addition of fibronectin to alb-hep conjugate-coated PS-CO(2) had no significant effect on the number of adhered platelets. Seeding of the substrates with ECs significantly reduced the number of adhered platelets under stationary conditions. Platelets deposited onto endothelialized surfaces were primarily found on endothelial cell edges, and sparingly on areas between ECs. In conclusion, alb-hep conjugate-coated surfaces display anticoagulant activity. ECs adhering to and proliferating on this coating significantly decrease the number of platelets which adhere to the surface. Therefore, alb-hep conjugate-coated surfaces form a suitable substrate for seeding of ECs in low density. Although application of fibronectin on top of the coating decreases the anticoagulant activity to some extent, it might be useful in view of the improved adherence of ECs to the coating.
Copyright 1999 John Wiley & Sons, Inc.