Ionic Liquids Shown to Break Bacterial Biofilm Layer

Biofilm-protected bacteria account for some 80% of total bacterial infections in humans and are 50 to 1000 times more resistant to antibiotics than simpler bacterial infections. Biofilms often persist beneath an intact, healthy skin layer and the difficulty of their treatment is largely due to the outermost layer of the skin being a natural barrier for drug delivery.

A unique class of materials, known as ionic liquids, neutralizes biofilm-forming pathogens and delivers drugs through the skin. Studies show that in several cases, ionic liquid is more efficacious on a biofilm than a standard bleach treatment. This has excellent prospects for aiding antibiotic delivery to the pathogen through biofilm disruption and the ionic liquids themselves are quite effective for pathogen neutralization, explained David Fox, a Los Alamos National Laboratory researcher on the project.

The team examined a panel of in-house synthesized ionic liquids and enabled the discovery of one ionic liquid, choline-geranate, which showed excellent antimicrobial activity, minimal toxicity to epithelial cells as well as skin, and effective permeation enhancement for drug delivery. Choline-geranate increased delivery of cefadroxil, an antibiotic, by 16-fold into the deep tissue layers of the skin without inducing skin irritation.