(428b) Invited Speaker: How Bacteria Read the Map: Effects of Surface Topography on Biofilm Formation

Bacterial adhesion on implanted biomaterials and formation of multidrug resistant biofilms can have catastrophic impacts on the infected individuals. As a major material property, surface topography plays an important role in biofilm formation. In this presentation, we will prevent a brief overview of this topic followed by a few of our studies aiming to control biofouling by engineering surface topography. By investigating bacterial adhesion on polymers with specific topographic patterns, we proposed a set of principles for rational design of antifouling surfaces and validated the design using protruding hexagonal patterns, which were found reduce biofilm formation of Escherichia coli by around 90%. Inspired by these findings, we further developed a new strategy to remove established biofilms using biocompatible shape memory polymers with micron-scale topographies. We demonstrate that this strategy can achieve a total reduction of Pseudomonas aeruginosa biofilms by 99.9% compared to the static flat control. It was also found effective against biofilms of Staphylococcus aureus and an uropathogenic strain of Escherichia coli. The detached cells were found to be more sensitive to antibiotics than the original biofilm cells, demonstrating synergic effects in biofilm control. These results inspired further improvement to develop biofilm control strategies with reversible shape memory polymers and active topography with beating pillars driven by electromagnetic actuation. Active topography was found to both inhibit biofilm formation and remove mature biofilms of P. aeruginosa by 99.9%, offering more prolonged control of biofouling. These results can help design better medical devices to prevent biofilm infections.