Plasma-engineered polymer thin films with embedded nanosilver for prevention of microbial adhesion
|Claire Saulou 1, Muriel Mercier-Bonin 2, Sandrine Zanna 3, Phillipe Marcus 3, Patrice Raynaud 1, Bernard Despax 1|
1. Laboratoire Plasma et Conversion d'Energie (LAPLACE), 118 Route de Narbonne, Toulouse 31062, France
Recently, there has been a growing interest in the study of metallic nanoclusters surrounded by an insulating matrix, to prevent microbial adhesion. The present project is thus focused on the plasma deposition of thin films (~100 nm) containing Ag nanoparticles embedded in a polymeric matrix, on stainless steel. Silver has been chosen for its broad-spectrum antimicrobial properties. Stainless steel AISI 316 L was selected 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 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-hexamethyldisiloxane plasma, using an asymmetrical RF discharge. The film properties can be controlled through changes of the operating conditions (precursor flow rate, applied power…). Polymeric matrix have been analysed by FTIR. The presence of Si-H, Si-O-Si, Si-(CH)n-Si and C-H groups was established. The Ag atomic compositions, evaluated by XPS measurements, 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. Ag antimicrobial effect is assumed to be related to Ag+ ion progressive release from the embedded particles. 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 have now to be optimized. The film stability will be also particularly investigated.
|Auxiliary resources (full texts, presentations, posters, etc.)|
Presentation: Oral at E-MRS Fall Meeting 2008, Symposium F, by Claire Saulou
See On-line Journal of E-MRS Fall Meeting 2008
Submitted: 2008-05-05 09:58 Revised: 2009-06-07 00:48