Development and evaluation of new nanoformulated thiolactone derivatives for enhanced disruption of pseudomonal biofilms

<i>Pseudomonas aeruginosa</i> (<i>P. aeruginosa</i>) is a formidable, antibiotic-resistant pathogen responsible for severe infections, particularly due to its ability to form protective biofilms mediated by the quorum sensing (QS) system, a cell-to-cell communication mechanism essential for biofilm formation and virulence. Herein, we developed a novel nanoformulation of thiolactone derivatives designed to target the QS system of <i>P. aeruginosa</i>. Specifically, chlorothiolactone (CTL) compounds (<i>m</i>CTL, 4a and <i>p</i>CTL, 4b) were encapsulated within biocompatible pluronic nanoparticles to enhance their delivery and efficacy. Our nanoformulation demonstrated efficient delivery of the designated molecules, leading to inhibition of the LasR receptor, a key regulator of QS, and subsequent disruption of biofilm formation. Our results revealed that the nanoparticle-formulated CTL derivatives exhibited superior activity in influencing the kinetics of <i>P. aeruginosa</i> biofilm and suppressing the virulence factors of <i>P. aeruginosa</i>, including pyocyanin and rhamnolipid production, compared to their free counterparts. Preliminary mechanistic studies indicated that the nanoformulation significantly reduced exopolysaccharide production, a critical component for biofilm integrity. Collectively, these findings underscore the potential of 4a-NPs and 4b-NPs as promising therapeutic candidates for combating <i>P. aeruginosa</i> infections by targeting its QS-mediated biofilm formation and virulence.