The project is focused on the plasma deposition of thin films (~100 nm) containing silver nanoparticles embedded in a polymeric matrix, on stainless steel. Silver has been chosen for its broad-spectrum antimicrobial properties and stainless steel AISI 316 L because of its extensive use in agro-food equipments and in biomedical devices. Nevertheless, a strong and specific microorganism adhesion was previously demonstrated on this surface. To avoid microbial adhesion, stainless steel surfaces were coated with plasma-mediated nanocomposite films. The process originality relies on a dual strategy associating Ag target sputtering and plasma polymerization in argon-HMDSO plasma, using an asymmetrical RF discharge (13.56 MHz). The film properties (Ag content, surface energy…) can be controlled through changes of the operating conditions (flow rate, RF power…). Polymeric matrix with or without Ag content have been analysed by FTIR. The presence of Si-H, Si-O-Si, Si-(CH)_n-Si and C-H groups was established. The silver atomic compositions, evaluated by XPS, were in the range 0-20%. To determine the anti-adhesive efficiency, detachment experiments were performed in a shear stress flow chamber. The maximal detachment efficiency was achieved with the polymeric matrix, thus confirming its anti-adhesive properties, probably due to a surface energy modification. Silver antimicrobial effect is assumed to be related to Ag⁺ ion progressive release from the embedded particles (resulting from metallic silver preliminary oxidation). The Ag⁺ release kinetics was confirmed by ICP-MS measurements: a maximal release was reached after 2 day-contact time. In parallel, film toxicity was evaluated: a significant decrease in cell viability was observed for the maximal silver composition of 20%. From an engineering point of view, film properties (thickness, silver content, hydrophilic/hydrophobic properties) have now to be optimized. The film stability will be also particularly investigated.

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