EPTFE Coating with Fibrin Glue, FGF-1, and Heparin: Effect on Retention of Seeded Endothelial Cells

Abstract

In an attempt to improve the resistance of seeded endothelial cell (EC) to desquamation due to shear stress, we evaluated the effect of coating expanded polytetrafluoroethylene (ePTFE) grafts with fibrin glue (FG) containing fibroblast growth factor 1 (FGF-1) and heparin on the retention of EC exposed to pulsatile flowex vivo.Five pairs of ePTFE grafts (30 μm internodal distance, 4 mm internal diameter, 7 cm long) were coated with either FG/FGF-1/heparin (fibrinogen 32.1 mg/ml, thrombin 0.32 U/ml, FGF-1 11 ng/ml, heparin 250 U/ml) or fibronectin (FN) (20 μg/ml). Canine jugular vein endothelial cells (Factor VIII+, passages 5–7), were radiolabeled with indium-111 (100 μCi/1 million cells). Cell seeding (3 × 105cells/cm2) was achieved by four successive inoculations of cells separated by 90° graft rotations. After overnight incubation (37°C), pairs of FG and FN grafts (5 cm long) were simultaneously perfusedex vivowith culture media containing 10% fetal bovine serum (120/80 mm Hg, 90 cc/min, 60 pulsations/min). During the 1-hr perfusion, perfusate samples were taken at 0, 5, 15, 30, and 60 min to determine radioactivity loss. Pre- and postperfusion whole graft radioactivity data were compared to estimate cell retention and confirmed by histologic evaluation. Mean adherent radioactivity on FG-coated grafts (96 ± 5%) was significantly higher (P= 0.0029, Student'sttest) than on FN-coated grafts (85 ± 3%). Maximum radioactivity loss in perfusate was seen after 5 min, with lower sustained loss thereafter. The improved retention of seeded EC on ePTFE grafts coated with FG containing FGF-1 and heparin compared to FN will need to be confirmed for longer durations of perfusion and usingin vivomodels.