PEG-PLGA nanoparticles deposited in Pseudomonas aeruginosa and Burkolderia cenocepacia

In our prior research, polymer nanoparticles containing tobramycin displayed robust antibacterial efficacy against biofilm-embedded Pseudomonas aeruginosa and Burkholderia cenocepacia cells, critical pathogens in cystic fibrosis. In the current study, we investigated the deposition of a nanoparticulate carrier composed of poly(D,L-lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol)-block-PLGA (PEG-PLGA) that was either covalently bonded with cyanine-5-amine or noncovalently bound with freely embedded cationic rhodamine B, which served as a drug surrogate. After exposing these nanoparticles to bacteria, we performed cell fractionation and fluorescence analysis, which highlighted the accumulation of cyanine-5-amine in the outer membranes and the accumulation of rhodamine B in the cytoplasm of cells. The results indicated that these organic nanoparticles are effective vehicles for targeted antibiotic delivery in bacterial cells, explaining the observed increase in the efficacy of encapsulated tobramycin against biofilms. This work emphasizes the potential of PEG-PLGA-based formulations for advanced drug delivery strategies.