The multi-faceted mechano-bactericidal mechanism of nanostructured surfaces

The bactericidal action delivered by rigid nanopillar arrays stems from the mechanical rupture of the bacterial cell membrane; however, the precise mechanism may be unique to the individual nanopillar geometries. In this study, we demonstrate that the bactericidal action of highly ordered, high-aspect-ratio nanopillar arrays may be associated with the relative flexibility of the individual nanopillars and the mechanical energy stored within the nanopillars. We propose that the lateral stretching of the cell membrane and interactions at the cell edge are induced by elastic pillar deformations that occur during bacterial adhesion. The results obtained in this study provide insight into a previously unknown category of mechano-bactericidal mechanism, highlighting another facet to the mechano-bactericidal action of nanostructured surfaces.