VASCULAR ENDOTHELIAL-CELL RESPONSES TO DIFFERENT ELECTRICALLY CHARGEDPOLY(VINYLIDENE FLUORIDE) SUPPORTS UNDER STATIC AND OSCILLATING FLOW CONDITIONS

We investigated the effect of electrically charged surface copolymers on endothelialization of four types of poly(vinylidene fluoride) (PVDF ) copolymer surface films with different electrical characteristics. P VDF films without a surface charge, with a remanent surface (5 and 7 m u C) and with piezoelectric characteristics were studied through the s ecretion by an endothelial cell (EC) line culture, under static and os cillating flow conditions, of prostacyclin (PG12) and thromboxane (TXA 2), two metabolites which have directly opposing actions on platelet f unction. The surface electrical properties of PVDF are suitable for pr omoting cell adhesion. Secretion of thrombomodulatory mediators varied , depending on the surface electrical charge and on the molecular stru cture of the PVDF substrate. Under static conditions the ECs respond t o the substrates by a similar increase of PG12. Under oscillating flow conditions, the ratio of PG12 to TXA2 is higher with the piezoelectri c PVDF film. The piezoelectricity generated from shear stress along th e entire length of the fibres may be appropriate in vivo to keep the [ PG12]/[TXA2] ratio at a level which could counteract the build-up of s urface deposits which could be at the origin of thrombosis. (C) 1996 E lsevier Science Limited.