Mechano-bactericidal nanostructured surface

Nature-inspired nanostructured surfaces with intrinsic mechano-bactericidal behaviors have drawn particular attention, owing to the advantages of biocompatibility, no cytotoxicity and free of biocides. However, when encountered with different bacterial strains, those nanostructured surfaces show significant different antibacterial activities because of the obvious variability in bacterial cell wall and morphology. Now a mechano-bactericidal nanostructured surface with photothermally enhanced antibacterial performances has been developed, which exhibits synergistic antimicrobial performances with significantly enhanced antibacterial efficiency against both Gram-positive and Gram-negative bacteria.

Photothermal layer

Firstly, a nanopillar surface with mechano-bactericidal properties is replicated by AAO template methods. Afterwards, a thin photothermal layer of polydopamine (PDA) was rapidly deposited on the nanostructured surface. The resultant nanopillar surface displays remarkably high antibacterial activities against both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). The main reason is due to the photothermal effect from the NIR irradiated PDA layer makes the bacterial cell membranes more susceptible to be killed by the structural rupture of the nanopillar surface. Additionally, the nanopillar surface also exhibited excellent hemocompatibility and cytocompatibility properties.

The study has been published in Progress in Organic Coatings, Volume 182, September 2023.