Projet ANR-07-BLAN-0196 – BIOPLEASURE : Plasma - surface engineering for biofilm prevention
Programme : Blanc (BLANC) 2007
Année de financement : 2007
Coordinateur du projet : UNIVERSITE TOULOUSE III [PAUL SABATIER] (UNIVERSITE TOULOUSE III [PAUL SABATIER])
Partenaires : Entreprise autre que TPE ou PME; Centre national de la recherche scientifique; Institut national des sciences appliquées de Toulouse; Université de Toulouse III - Paul Sabatier
Montant : 480000.0 euros
Date de début : 2007
Durée : 36 mois
Résumé : "Surface-engineered structures for the prevention of biofilm: introduction of plasma processes -  Bacterial and fungal biofilms have the potential to act as a chronic source of microbial contamination which may compromise the food quality and safety. In the biomedical field, infections related to medical devices are also a national public health issue. This has fuelled an explosion of research in surface science for applications in the health and biomedical device industry, food industry and personal hygiene industry. Resulting coatings need to combine valuable attributes such as potent antimicrobial efficiency, environmental safety, low toxicity for humans and ease of fabrication. -  Plasma processes, which are classified as dry processes, represent an interesting approach for modification and/or functionalization of solid surfaces. They present significant advantages compared to wet processes or classical chemical routes, such as low amount of added precursors, low amount of waste products or gas exhaust and a reduced environmental impact. A plasma surface preparation is also well adapted to the conception of biomaterials because it is easy to reproduce and to clean. Furthermore, plasma processes constitute smart processes which can be well adapted and controlled through ""external parameters"". In particular, cold plasma surface treatments represent an efficient, non-polluting and economical alternative to clean and activate stainless steel surfaces. The plasma-mediated functionalities onto the surface are generally carboxyl, hydroxyl, amine and aldehyde groups which are the main sites for the covalent immobilization of biologically active molecules. Recent works have introduced plasma processes for fouling and/or biofilm-targeted surface modification. In vitro microbial adhesion and growth could effectively be reduced by plasma treatment, due to a more hydrophilic surface even though in vivo results were mitigated. Plasma processes can also be integrated as a pre-functionalization step, followed by a wet chemical treatment. Other authors used plasma immersion ion implantation to modify medical-grade PVC coated withy triclosan and bronopol biocides. The modified samples exhibited good performance with regard to the adhesion and killing of S. aureus and E. coli even though the surface properties were shown to deteriorate after ten days. Finally, there is a wide range of potentialities of plasma techniques for specific biological applications (e.g., medical devices, hygienic prevention of nosocomial diseases, food packaging). Plasma-surface engineering appears to be a powerful tool for modifying and adapting materials, which can be verified by the increasing number of scientific papers and patents, and the commercialisation of some well adapted biomaterials and packaging. -  2. General objective -  The general objective of the present proposal is to design cold plasma-mediated surface treatments of solid surfaces (stainless steel, titanium and polymers as targeted materials) for implementation in food-processing environments and biomaterial medical devices. This could discourage the formation of biofilms (bacteria, fungi) and lead to an improved hygiene, thus satisfying actual socio-economical constraints and health concerns. To this aim, plasma-deposited silver nanocomposite thin films will be developed and optimized. They combine the non-fouling potentialities of a controllable organic matrix with the broad-spectrum antimicrobial properties of silver, the chemical reactivity of which is enhanced through inclusion as nanoclusters. To achieve this ambitious goal, our strategy includes: (i) the definition of the operating cold plasma conditions enabling an optimal surface coating (composition, anti-adhesive and/or biocide properties, mechanical and chemical resistance, durability, release); (ii) the characterization of the plasma-modified solid surfaces using nano-scale analytical techniques and (iii) the quantification of the