Nat. Commun. https://doi.org/10.1038/s41467-018-06884-w (2018)

Biofilms forming around bacterial colonies interfere with the diffusion and penetration of antibiotics within the bacterial cell layers, leading to decreased antimicrobial efficiency and increased resistance. Although pharmacological treatments have been used to disturb biofilm integrity, these are targeted to specific bacterial species. Physical disruption of biofilms might represent a generally applicable alternative.

In their recent paper, Teirlinck and colleagues incubate bacterial biofilms with gold nanoparticles and show that the heat produced on laser irradiation of the nanoparticle causes water within the biofilm to evaporate and form vapour nanobubbles. The nanobubbles can locally disrupt the integrity of the biofilm and enlarge the space between the cells in the bacterial community, increasing its permeability to small molecules. As a result of the treatment, three different Gram-positive and Gram-negative bacteria displayed increased susceptibility to the antibiotic tobramycin. By using the localized effect of laser irradiation, the approach reduces side effects and promises to be valuable for the care of superficial wounds and infections, owing to its low toxicity and negligible heat transfer to the surrounding environment.