Modification of cellulose thin films with lysine moieties: a promising approach to achieve antifouling performance

Abstract

Thin films of trimethylsilyl cellulose are obtained by spin coating and regenerated to cellulose. The surface is activated with N,N′-carbonyldiimidazole and aminolysis with lysine is carried out in aqueous solution to yield a cellulose lysine carbamate film. The surface is analytically characterized by ATR-IR spectroscopy, zetapotential measurements, contact angle measurements, and atomic force microscopy. The amount of functional groups is determined by pH potentiometric titration as well as the ninhydrin test and is in the range of 25 pmolcm−2. Adsorption of bovine serum albumine (BSA) and fibrinogen on the cellulose film and the cellulose lysine carbamate surface is studied at different pH values by quartz crystal microbalance with dissipation monitoring (QCM-D). The adsorption of BSA is significantly reduced by modification with lysine. At physiological pH value (7.4) the adsorption of fibrinogen is even six times lower (1.0 mgm−2) compared to the pure cellulose surface. Thus, cellulose thin films with lysine moieties are promising candidates for hemo-compatible antifouling surfaces in the field of blood contacting devices.