Study of bacterial adhesion on biomimetic temperature responsive glycopolymer surfaces

Pseudomonas aeruginosa is an opportunistic pathogen responsible for diseases such as bacteremia, chronic lung infection, and acute ulcerative keratitis. P. aeruginosa induced diseases can be fatal as the exotoxins and endotoxins released by the bacterium continue to damage host tissues even after the administration of antibiotics. As bacterial adhesion on cell surfaces is the first step in bacterial based pathogen infections, the control of bacteria-cell interactions is a worthwhile research target. In this work, thermally responsive poly(N-isopropylacrylamide) [P(NIPAAm)] based biomimetic surfaces were developed to study the two major bacterial infection mechanisms, which is believed to be mediated by hydrophobic or lectin-carbohydrate interactions, using quartz crystal microbalance with dissipation. Although, a greater number of P. aeruginosa adhered to the NIPAAm homopolymer modified surfaces at temperatures higher than the lower critical solution temperature (LCST), the bacterium-substratum bond stiffness was stronger between P. aeruginosa and a galactose based P(NIPAAm) surface. The high bacterial adhesion bond stiffness observed on the galactose based thermally responsive surface at 37 °C might suggest that both hydrophobic and lectin-carbohydrate interactions contribute to bacterial adhesion on cell surfaces. Our investigation also suggests that the lectin-carbohydrate interaction play a significant role in bacterial infections.