Anti-fouling phosphorylcholine bearing polyelectrolyte multilayers: Cell adhesion resistance at rest and under stretching

We investigate the anti-fouling properties of polyelectrolyte multilayers bearing phosphorylcholine and triethylene glycol moieties and their adhesive response under stretching towards mammalian cells and fungi. More precisely we use a precursor multilayer deposited on glass and on an elastomeric silicone sheet and onto which one or two layers of polyacrylic acid modified with triethylene glycol or phosphorylcholine groups are added. In previous studies, these architectures proved to be resistant to protein adsorption (A. Reisch, J. C. Voegel, E. Gonthier, G. Decher, B. Senger, P. Schaaf and P. J. Mesini, Langmuir, 2009, 25, 3610; A. Reisch, J. Hemmerle, J. C. Voegel, E. Gonthier, G. Decher, N. Benkirane-Jessel, A. Chassepot, D. Mertz, P. Lavalle, P. Mesini and P. Schaaf, J. Mater. Chem., 2008, 18, 4242.). Here we investigate the adhesion of mammalian cells (fibroblasts) and of fungi (Candida albicans) both at rest and under uniaxial stretching of the substrate. Two layers of these polyelectrolytes yield surfaces that are practically resistant to the adhesion of fungi and mammalian cells at rest. Under stretching of the substrate, fungi adhesion remains almost totally prevented at least up to a stretching degree of 1.5, while fibroblast adhesion remains only prevented up to a stretching degree of 1.2. Fibroblast adhesion starts to take place and increases when the substrate is further stretched. The onset of fibroblast adhesion under stretching is retarded for phosphorylcholine containing films compared to those that contain triethylene glycol. These systems thus provide a first example of surfaces that present excellent anti-fouling properties at rest and become specifically adhesive under stretching.