Bactericidal mechanism of nanopatterned surfaces

The quest to design and fabricate new antibacterial surfaces is an important task to meet the urgent demands of biomedical applications. Recently, a mechanical mechanism for killing adherent bacteria was discovered on nanopatterned surfaces, but there is a lack of understanding of the bactericidal mechanism. Here we present a quantitative thermodynamic model to study the bactericidal mechanism of nanopatterned surfaces through analyzing the total free energy change of bacterial cells. By comparing the bacterial cells on a flat surface and nanopatterned surface, our theoretical results reveal that cicada wing-like nanopatterned surfaces have more effective bactericidal properties than flat surfaces because a patterned surface leads to a drastic increase of the contact adhesion area. Our model also reveals some details of the influence mechanism, and gives some important information about how to improve the bactericidal properties through designing the morphology of the patterned surface.