Covalent Grafting of Fibronectin onto Plasma-Treated PTFE: Influence of the Conjugation Strategy on Fibronectin Biological Activity Karine Vallie `res, E ´ ric Petitclerc, Gae ´tan Laroche * Introduction Small diameter poly(tetrafluoroethylene) (PTFE) vascular prostheses currently implanted in humans have a low patency rate. It has been well established that the outcome of biomaterials after implantation depends on tissue– material interactions. For blood contacting materials, these interactions begin with the adsorption of plasmatic proteins which occurs within seconds after the implanta- tion. [1,2] This phenomenon, called the Vroman effect, depends on material properties such as hydrophobicity, roughness, charge, stiffness as well as plasma composition Full Paper Surface coating of synthetic materials is often considered to improve biomedical devices biocompatibility. In this study, we covalently bound fibronectin (FN) onto ammonia plasma- treated PTFE via two crosslinkers, namely glutaric anhydride (GA) and sulfosuccinimidyl- 4-( p-maleimidophenyl)butyrate (sulfo-SMPB). With respect to clean PTFE, cell adhesion increased markedly on both FN grafted surfaces, although it was twice higher on PTFE-GA-FN than on PTFE-SMPB-FN. ELISA experiments performed with a polyclonal antibody revealed that the amount of FN is identical on both surfaces while monoclonal antibody specific to the RGD binding site clearly demonstrated a greater availability when FN is surface grafted through GA. These results provide evidence of a vari- ation in protein con- formation correlated with the surface con- jugation strategy. K. Vallie `res, E ´ . Petitclerc, G. Laroche Unite ´ de Biotechnologie et de Bioinge ´nierie, Centre de recherche du CHUQ, Ho ˆpital Saint-Franc ¸ois d’Assise, 10 rue de l’Espinay, Que ´bec, Canada, G1L 3L5 Fax: (þ1) 418 656 5343; E-mail: gaetan.laroche@gmn.ulaval.ca K. Vallie `res, G. Laroche Laboratoire d’inge ´nierie de surface, De ´partement de Ge ´nie des mines, de la me ´tallurgie et des mate ´riaux, Faculte ´ des sciences et genie, Universite ´ Laval, Que ´bec, Canada, G1K 7P4 E ´ . Petitclerc De ´partement de Me ´decine, Faculte ´ de Me ´decine, Universite ´ Laval, Que ´bec, Canada, G1K 7P4 738 Macromol. Biosci. 2007, 7, 738–745 ß 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim DOI: 10.1002/mabi.200600267