Lipid-Polymer Hybrid Nanoparticles Enhance the Potency of Ampicillin against <i>Enterococcus faecalis</i> in a Protozoa Infection Model

Enterococcus faecalis (E. faecalis) biofilms are implicated in endocarditis, urinary tract infections, and biliary infections. Coupled with E. internalization into host cells, this opportunistic pathogen poses great challenges to conventional antibiotic therapy. The inability of ampicillin (Amp) eradicate bacteria hidden intracellular niches greatly reduces its efficacy against complicated To enhance the potency Amp different forms was loaded Lipid-Polymer hybrid Nanoparticles (LPNs), a highly efficient nano delivery platform consisting unique combination DOTAP lipid shell PLGA polymeric core. antibacterial activity these nanoparticles (Amp-LPNs) investigated protozoa infection model, achieving much higher multiplicity (MOI) compared studies using animal phagocytes. A significant reduction total observed all groups receiving 250 μg/mL Amp-LPNs same concentration free during three interventions, simulating acute chronic infections prophylaxis. In early intervention, no viable after 3 h LPNs treatment whereas did not clear 24 treatment. also enhanced at late intervention boosted survival rate approaching 400%, where were identified 40 postinfection time point. Prophylactic effectiveness exhibited both elimination toward subsequent Using as surrogate model for phagocytes study high MOI suggests that LPN-formulated antibiotics hold potential significantly improve therapeutic outcome bacterial