Abstract
Purpose: :
We report the first use of dicationic bis-phosphonium ionic liquids as antimicrobial agents.
Methods: :
We synthesized a variety of ionic liquid compounds and identified a particular molecule, designated Di-Hex C10, which possess two positively charged phosphonium groups separated by ten methylene units in a "bola" type configuration. This compound was tested for both in vitro and in vivo antimicrobial activity.
Results: :
Di-Hex C10 demonstrated broad in vitro antimicrobial activity at the low micromolar concentrations versus Gram-negative and Gram-positive organisms, including MRSA strains, as well as Candida albicans. Treatment with Di-Hex C10 resulted in bacterial killing in as little as 10 minutes in vitro. Di-Hex C10 showed little cytotoxicity at 1 µM versus a corneal epithelial cell line or at 10 µM in a mouse corneal wound model. Di-Hex C10 also prevented infection by Pseudomonas aeruginosa in a mouse corneal wound model of infection using a single dose.
Conclusions: :
Our data suggests that diphosphonium ionic liquid may represent a new class of broad-spectrum antimicrobial agents suitable for use on the ocular surface.
Keywords: antibiotics/antifungals/antiparasitics • microbial pathogenesis: experimental studies • cornea: basic science