EFFECTS OF AMIDE AND AMINE PLASMA-TREATED EPTFE VASCULAR GRAFTS ON ENDOTHELIAL-CELL LINING IN AN ARTIFICIAL CIRCULATORY-SYSTEM

We sought to examine whether surface modification of expanded polytetr afluoroethylene (ePTFE) vascular grafts might extend graft patency wit hout modifying the graft structure. Amide and amine plasma (butylamine ) were applied to graft surfaces using radio frequency glow discharge. Surface analyses by Fourier transform infrared spectroscopy-attenuate d total reflectance, X-ray photoelectron spectroscopy, and dynamic con tact angle measurements revealed the presence of nitrogen-containing f unctional groups on the plasma modified graft surfaces, along with an increased surface hydrophilicity. Bovine aortic endothelial cells were seeded on amide and amine plasma coated ePTFE vascular grafts; and pl aced inside an artificial circulatory system under well-defined flow c onditions. The seeded endothelial cells were exposed to either constan t or pulsatile flow condition far 5 days. Their corresponding maximum wall shear stresses were 1 dyn/cm(2) under constant flow and 65, 108, and 259 dyn/cm(2) under various pulsatile flows. Plasma modified ePTFE vascular grafts enhanced the endothelial cell Lining under constant a nd pulsatile now conditions, Fluorescence nuclear staining, scanning e lectron microscopy, and histological staining indicated the formation of an endothelial cell monolayer on the plasma coated graft surfaces. (C) 1998 John Wiley & Sons, Inc.