Proof of the effectiveness of novel bioinspired antimicrobial nanostructures

Abstract Antimicrobial surfaces are a promising option for supporting hygiene measures. In addition to many different technologies, research is also ongoing into coatings that are modelled on natural surfaces. In an international project with the National Nanotechnology Laboratory in Costa Rica, the Technical University of Applied Sciences Amberg-Weiden is working on such an aluminum-based nanostructured coating, which is modelled on insect wings and has an antibacterial effect in nature. The aim is to test the effectiveness of these surfaces against bacterial pathogens (Escherichia coli and Staphylococcus aureus) in a standard test procedure, as well as to investigate the resistance of the nanostructures to abrasion and reprocessing. Since the effect of such surfaces depends on the filigree nanostructure, resistance to possible abrasion or damage is a key factor here. Our results show that these coatings exhibit at least detectable activity (log 2.2) against the bacteria in the ISO 22196 test setup. Even after repeated wiping of the coatings with sterile water or reprocessing using ultrasound and wipe disinfection, no loss of effectiveness can be detected. Due to the intrinsic antimicrobial effect of the aluminum, the effectiveness of the nanostructured surface is even higher compared to a completely ineffective control surface. If further studies confirm these initial positive results, the coating we investigated could represent another effective alternative in infection control and prevention.