Abstract

The search for a nonthrombogenic material having patency to be used for small diameter vascular graft applications continues to be a field of extensive investigation. The purpose of the present study was to examine whether surface modification of polytetra fluoroethylene (PTFE, Teflon) and polyethylene-terephthalate (Dacron) vascular grafts might extend graft biocompatibility without modifying the graft structure. A series of surface coatings were prepared by modifying the argon plasma-treated PTFE and Dacron grafts with collagen IV and laminin and subsequently immobilizing bioactive molecules like PGE1, heparin or phosphatidyl choline via the carbodiimide functionalities. Surface analysis by Fourier transform infrared spectroscopy-attenuated total reflectance revealed the presence of new functional groups on the modified graft surfaces. In vitro studies showed that fibrinogen adsorption and platelet adhesion on modified grafts were significantly reduced. This study proposes that surface grafting of matrix components (collagen-type IV and laminin) and subsequent immobilization of bioactive molecules (PGE1, heparin or phosphatidyl choline) changed the surface conditioning of vascular grafts and subsequently improved their biocompatibility. However, more detailed in vivo studies are needed to confirm these observations.