Bacterial adherence on self-assembled films of brush polymers bearing zwitterionic sulfobetaine moieties

In this study we synthesized a series of well-defined brush polymers, poly(oxy(11-(3-sulfonylpropyltrimethylglycinyl)undecylesterthiomethyl) ethylene-co-oxy(n-dodecylthiomethyl)-ethylene)s (PECH-DMAPSm, where m is the mol% of DMAPS (sulfobetaine) end group). The thermal properties and phase transitions of these polymers were investigated. The polymers were thermally stable up to 185 °C. The polymers were found to form favorably into multi-bilayer structures, always providing hydrophilic, zwitterionic sulfobetaine end groups at the film surface. For the films, water sorption behavior was examined. In addition, surface energy components were determined for the polymer films and the bacterial cells deposited on cellulose acetate membranes. The brush polymer films were found to suppress bacterial adherence significantly. An understanding of the suppression of bacterial adherence was attempted in terms of surface energies and thermodynamics. The results collectively indicate that the sulfobetaine-containing brush polymers are suitable for use in biomedical applications that require the reduced possibility of post-operative infection.