Biocompatible nanocarrier fortified with a dipyridinium-based amphiphile for eradication of biofilm.

Annihilation of bacterial biofilms is challenging owing to their formidable resistance to therapeutic antibiotics and thus there is a constant demand for development of potent antibiofilm agents that can abolish established biofilms. In the present study, the activity of a dipyridinium-based cationic amphiphile (compound 1) against established bacterial biofilms and the subsequent development of a compound 1-loaded nanocarrier for potential antibiofilm therapy are highlighted. Solution-based assays and microscopic analysis revealed the antagonistic effect of compound 1 on biofilms formed by Staphylococcus aureus MTCC 96 and Pseudomonas aeruginosa MTCC 2488. In combination studies, compound 1 could efficiently potentiate the action of tobramycin and gentamicin on P. aeruginosa and S. aureus biofilm, respectively. A human serum albumin (HSA)-based nanocarrier loaded with compound 1 was generated, which exhibited sustained release of compound 1 at physiological pH. The compound 1-loaded HSA nanocarrier (C1-HNC) displayed the signature membrane-directed activity of the amphiphile on target bacteria, efficiently eliminated established bacterial biofilms, and was observed to be nontoxic to a model human cell line. Interestingly, compound 1 as well as the amphiphile-loaded HSA nanocarrier could eradicate established S. aureus biofilm from the surface of a Foley's urinary catheter. On the basis of its biocompatibility and high antibiofilm activity, it is conceived that the amphiphile-loaded nanocarrier may hold potential in antibiofilm therapy.