Insect Ultra-Structures as Effective Physical-Based Bactericidal Surfaces

Bacteria colonization of substrates is a key issue threatening the health of humans worldwide. This review summarized recent bactericidal activity evidence of different structures developed by insects. We evaluated different mechanisms in bactericidal activity among several insect species, and we also provided a glimpse at attempts at fabricating bactericidal bioinspired structures. In addition, we investigated the link between species with mechano-bactericidal surfaces and their evolution and ecological dynamics. It emerged that mostly hemimetabolous insects evolved bactericidal nanostructures on their wings, probably due to development of their wings externally during postembryonal development. Whereas, holometabolous insects, which develop their wings internally during metamorphosis, have their wings exposed to the environment just in the adult instar, and thus subjected to bacteria for a shorter period compared to hemimetabolous insects. Bio-inspired high-aspect-ratio nanopillared surfaces with bactericidal properties might broaden the application area of bactericidal surfaces, to mechanically decrease the number of bacterial infections.