(266a) Invited Talk: Polymer Thin Film Surface Area and Stiffness Influences Bacteria Inactivation and Biofilm Formation

The development of environmentally benign polymer coatings that effectively prevent surface contamination by microorganisms is a pressing necessity. As both microbial resistance and infectious diseases remain, new approaches to delay the onset of biofilm formation with less evolutionary pressure on pathogens are needed. In this work, we explore the effect that materials properties have on inactivating planktonic bacteria and altering the structure of young microbial biofilms. In the first study, we focus on the effect that the available surface-to-volume ratio has on Escherichia coli, Pseudomonas aeruginosa, and Bacillus anthracis inactivation when the bacteria is challenged with chitosan, a copolymer of 2-acetamido-2-deoxy-D-glucopyranose and 2-amino-2-deoxy-D-glucopyranose units joined by β(1→4) bonds. Due to the availability of primary amine groups, chitosan exhibits inherent antimicrobial activity; the proposed mechanism is the interaction between the positive charge on the C-2 of the glucosamine monomer and negatively charged microbial cell membrane. In a second system, we look towards the field of mechanobiology – where it is theorized that fundamental cell processes are modulated by the substrate matrix stiffness. Here, we characterize the formation and growth of P. aeruginosa biofilms grown on mechanically variable polymer films. Characterization of the extrapolymeric substances (EPS) matrix of the biofilm as a function of the mechanical properties of a model polymer film were conducted. Results on the interaction of the nano- to macro- structured thin films with bacteria viability and EPS formation will be presented.