Bioinspiration for battling bacteria: Nature inspired high aspect ratio nanostructures for new age antibacterial surfaces

Abstract

Bacterial colonization and biofilm formation on abiotic surfaces effectuate corrosion, fermentation, and infection resulting in tremendous economic and human losses each year. Aggravating the situation, new multi-drug resistant bacterial strains are emerging continuously, aided by the artificial selection of such strains due to antibiotic overuse, and spreading across the globe through living and non-living carriers. Deaths from drug-resistant microbial infections are rising while approvals of new antibiotic classes have been falling for more than a decade. Under such a scenario, the quest for alternative antibacterial strategies has gained the utmost importance. Nanomaterials such as metal nanoparticles, graphene, and more recently, bioinspired nanotopographies are among the most promising solutions to tackle this problem. Almost a decade ago, it was discovered that nanopillar topography of insect wings such as cicadas, dragonflies and damselflies can kill bacteria by physically rupturing their cell wall as the cells try to attach to the surface. This exciting discovery meant that if such topographies could be successfully emulated on surfaces of choice, the need for antibiotic administration could be eliminated and development of drug-resistant strains can be curtailed. This thesis focuses on engineering such bioinspired nanostructured surfaces to combat the spread of bacterial infections. The first part of the work in the thesis aims to replicate various high aspect ratio nanostructures on material surfaces, assess their bactericidal activity through experimental measurements and understand the various aspects of the mechanobactericidal phenomena. The second part of the thesis aims to develop technologies for affordable, and scalable adoption of these structures.