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Biofilm-protected microbial infections in skin are a serious health risk that remains to be adequately addressed. The lack of progress in developing effective treatment strategies is largely due to the transport barriers posed by the stratum corneum of the skin and the biofilm. In this work, we report on the use of Ionic Liquids (ILs) for biofilm disruption and enhanced antibiotic delivery across skin layers. We outline the syntheses of ILs, analysis of relevant physicochemical properties, and subsequent neutralization effects on two biofilm-forming pathogens: Pseudomonas aeruginosa and Salmonella enterica. Further, the ILs were also examined for cytotoxicity, skin irritation, delivery of antibiotics through the skin, and treatment of biofilms in a wound model. Of the materials examined, choline-geranate emerged as a multipurpose IL with excellent antimicrobial activity, minimal toxicity to epithelial cells as well as skin, and effective permeation enhancement for drug delivery. Specifically, choline-geranate was comparable with, or more effective than, bleach treatment against established biofilms of S. enterica and P. aeruginosa, respectively. In addition, choline-geranate increased delivery of cefadroxil, an antibiotic, by >16-fold into the deep tissue layers of the skin without inducing skin irritation. The in vivo efficacy of choline-geranate was validated using a biofilm-infected wound model (>95% bacterial death after 2-h treatment). This work establishes the use of ILs for simultaneous enhancement of topical drug delivery and antibiotic activity.

Analytical capabilities to identify dyes associated with structurally robust wool fibers would critically assist crime-scene and explosion-scene forensics. Nondestructive separation of dyes from wool, removal of contaminants, and dye analysis by MALDI- or ESI-MS, were achieved in a single-pot, ionic liquid-based method. Ionic liquids (ILs) that readily denature the wool α-keratin structure have been identified and are conducive to small volume, high-throughput analysis for accelerated threat-response times. Wool dyed with commercial or natural, plant-based dyes have unique signatures that allow classification and matching of samples and identification of dyestuffs. Wool released 0.005 mg of dye per mg of dyed wool into the IL, allowing for analysis of single-thread sample sizes. The IL + dye mixture promotes sufficient ionization in MALDI-MS: addition of common MALDI matrices does not improve analysis of anionic wool dyes. An inexpensive, commercially available tetrabutylphosponium chloride IL was discovered to be capable of denaturing wool and was determined to be the most effective for this readily fieldable method.