Vertically aligned multi walled carbon nanotubes prevent biofilm formation of medically relevant bacteria

A significant part of human infections is frequently associated with the establishment of biofilms by (opportunistic) pathogens. Due to the increasing number of untreatable biofilms, there is a rising need to develop novel and effective strategies to prevent biofilm formation on surfaces in medical as well as in technical areas. Bacterial initial attachment and adhesion to surfaces followed by biofilm formation is highly influenced by the physical properties of the surfaces. Consequently, changing these properties or applying different nanostructures is an attractive approach to prevent biofilm formation. Here we report on the effect(s) of surface grown and anchored vertically aligned multi walled carbon nanotubes (MWCNT), which have been made wettable by immersion through a graded ethanol series, on biofilm formation of Klebsiella oxytoca, Pseudomonas aeruginosa, and Staphylococcus epidermidis. We evaluated the biofilm formation under continuous flow conditions by confocal laser scanning microscopy and scanning electron microscopy, and demonstrated significant inhibition of biofilm formation of all the different pathogens by MWCNT of different lengths. Furthermore, the anti-adhesive effects of the MWCNT increased with their overall length. The application potential of our findings on surface grown and anchored vertically aligned MWCNT may represent a suitable contact mechanics based approach to prevent biofilm formation on medical devices or technical sensors operating in fluid environments.