Event Abstract Back to Event In vivo prevention of biofilm formation and associated occlusion by biomimetic glycocalyxlike polymer in totally implantable venous access devices Ashwini Chauhan1, Aude Bernardin2, Windy Mussard2, Irène Kriegel3, Marc Esteve3, Jean-Marc Ghigo1, Christophe Beloin1 and Vincent Semetey2, 4 1 Institut Pasteur, Institut Pasteur, Unité de Génétique des Biofilms, Département de Microbiologie, France 2 Institut Curie, UMR 168 CNRS, Laboratoire de Physicochimie "Curie", France 3 Institut Curie, Service Anesthésie-Réanimation-Douleur, Hôpital, France 4 Chimie Paristech, Institut de Recherche de Chimie Paris - UMR 8247 CNRS, France The role of medical devices in healthcare is essential. This is particularly the case of totally implantable venous access devices (TIVAD) that have led to great improvement of patients admitted in oncology, nephrology and intensive care units due to ease in administering fluids and performing blood sampling. Although catheters improve healthcare of patients, the hydrophobic nature of their surface material (polyurethane, polydimethylsiloxane) promotes protein adsorption and cell adhesion. Catheters are therefore prone to complications such as thrombosis and infections with the colonization by pathogenic microorganisms mainly via endoluminal contamination, which leads to development of complex bacterial and fungal biofilm communities. Biofilms display high tolerance towards the immune system and various antimicrobials and are thus difficult to eradicate. Currently, there is no fully efficient method for treating catheter-related biofilms besides traumatic and costly removal of colonized devices. In this study, we describe the in vivo efficacy of bio-inspired glycocalyx-like anti-adhesive coatings to inhibit Staphylococcus aureus and Pseudomonas aeruginosa colonization on commercial totally implantable venous access devices in a clinically relevant rat model of biofilm infection. Materials and Methods: We developed, a one step, strategy to graft onto polydimethylsiloxane elastomers glycocalyx-like methylcellulose polymer nanofilms in water via hydrosylilation taking advantage of free SiH groups remaining in commercial silicone elastomers. A similar approach was used to graft Titanium port via Thiol-ene reaction. The resulting covalently modified surfaces were found to reduce significantly protein adsorption as well as cell adhesion in vitro acting by steric repulsion mechanism. These surface chemistry strategies were used to modified the whole internal and external surface of commercial TIVAD. We tested the in vivo efficacy of the modified TIVAD using a clinically relevant rat model of biofilm-associated infections with trackable bioluminescent bacteria (S. aureus, P. aeruginosa) on later stages of biofilm formation by monitoring TIVAD colonization for 5 days upon device contamination. Results and Discussion: While non-coated TIVAD implanted in rats were heavily colonized by the two biofilm-forming pathogens with high percentage of occlusion, coating of TIVAD reduced significantly their initial adherence and subsequently led to a 5-log reduction in biofilm formation and reduced blood clot occlusion. Conclusion: This study provides an in vivo proof that an antiadhesive surface strategy on a fully functional implantable catheter is efficient to lower the risk of both complications associated with TIVAD use, infections and thrombosis. This approach constitutes an efficient universal prophylactic strategy for controlling complications in medical devices.