Interplay between molecular architecture, interfacial properties, and microbial settlement of polyoxazoline-based films
Surface charges are important for the adsorption of proteins and the settlement of microorganisms at surfaces. In a collaborative project with the BioInterface Group of Prof. M. Textor (Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich), we studied the impact of poly(L-lysine)-graft-poly(2-methyl-2-oxazoline) (PLL-g-PMOXA) copolymers on the mechanisms involved in the non-specific adhesion of Escherichia coli (E. coli) bacteria. The adhesion of non-fimbriated bacteria was found to be dependent on the interfacial net charge and ionic strength of the media. Fimbriated (type I) E. Coli adhered rather independent on both parameters, and the adhesion was determined by non-specific van der Waals and hydrophobic interactions of the proteins at the fimbrial tip. PLL-g-PMOXA films with a PLL grafting density of α = 0.33, characterized by the highest PMOXA chain density and a surface charge close to zero, effectively inhibited the statement with both bacterial strains.
(A) Schematic representation of the PLL-g-PMOXA copolymer films after selfassembly onto niobia substrates. (B) Pressure-normalized streaming current in 1 mM HEPES + 1 mM KCl solution. (C) Representative phase contrast images of fimbriated E. coli adhering to the differenty modified niobia surfaces after 1 h incubation at room temperature. Adapted from Biomaterials 2010, 31, 9462-9472, Pidhatika et al. The role of the interplay between polymer architecture and bacterial surface properties on the microbial adhesion to polyoxazoline-based ultrathin films. Copyright 2010, with permission from Elsevier.
References
[1] Pidhatika et al. The role of the interplay between polymer architecture and bacterial surface properties on the microbial adhesion to polyoxazoline-based ultrathin films. Biomaterials 2010, 31, 9462, doi: https://doi.org/10.1016/j.biomaterials.2010.08.033