Bacteria-targeting surfaces: Fine tuning interactions for different outcomes

Two classes of engineered surfaces have generally been pursued for bacterial control: Some surfaces aim to kill bacteria while others aim to selectively adhere bacteria in sensing applications. (Here the killing surfaces are not materials that leach compounds that are later taken up in solution by the bacteria.) Both applications require bacterial adhesion but the bacterial adhesion must be tuned. Bacteriocidal surfaces that are too strongly adhesive or to disruptive could lyze bacteria (for instance inducing an immune response to implants) or simply foul, losing their activity. If adhesion is to weak there will be insufficient contact for killing. We review here, a new strategy that clusters adhesive antimicrobial functionality in ways that preserves killing activity at the same time reducing adhesion to the point where bacteria can be readily removed and the surface reused. We will also discuss fine points of bacterial interactions with PEGylated surfaces designed to be non-adhesive.