Responses Towards Surface-modified Expanded Polytetrafluoroethylene Fibers

ABSTRACT: The effect of various surface modifications, in conjunction with the intrinsic surface features of expanded polytetrafluoroethylene (ePTFE) fibers on endothelialization, were investigated. A multi-step surface modification strategy was applied to commercial ePTFE sutures and then the effect of surface topography and surface chemistry involving cell adhesive and cell-resistant molecules was evaluated towards endothelial cell adhesion and its spreading. N-hepthylamine plasma polymer (HApp) was deposited onto the ePTFE fiber surface and then carboxy-methyl-dextran (CMD) was covalently attached. Subsequently, GRGDS and GRGES peptides were covalently grafted onto the CMD graft layer. The micrometric and nanometric features of ePTFE were qualitatively examined by atomic force microscopy, and scanning electron microscopy. Human umbilical vein endothelial cells (HUVECs) were used to evaluate the in vitro cell adhesion on nonmodified fibers and the multi-step surface coatings. Cell adhesive molecules (HApp and RGD) enhanced the cell adhesion while cell-resistant molecules (CMD and RGE) and nonmodified fibers resisted cell adhesion. Therefore, only surface features have no effect on the HUVEC adhesion and that the surface chemistry is dominant in modulating HUVEC adhesion on ePTFE fibers