Open AccessLipid-Polymer Hybrid Nanoparticles Enhance the Potency of Ampicillin against Enterococcus faecalis in a Protozoa Infection Model
Author(s) -
Chuan Hao Tan,
Lai Jiang,
Wenrui Li,
Siew Herng Chan,
Jong-Suep Baek,
Noele Kai Jing Ng,
Talgat Sailov,
Sharad Kharel,
Kelvin Kian Long Chong,
Say Chye Joachim Loo
Publication year - 2021
Publication title -
acs infectious diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.324
H-Index - 39
ISSN - 2373-8227
DOI - 10.1021/acsinfecdis.0c00774
Subject(s) - enterococcus faecalis , microbiology and biotechnology , ampicillin , biofilm , multiplicity of infection , protozoa , biology , bacteria , potency , antibiotics , staphylococcus aureus , in vitro , biochemistry , genetics
Enterococcus faecalis ( E. faecalis ) biofilms are implicated in endocarditis, urinary tract infections, and biliary tract infections. Coupled with E. faecalis internalization into host cells, this opportunistic pathogen poses great challenges to conventional antibiotic therapy. The inability of ampicillin (Amp) to eradicate bacteria hidden in biofilms and intracellular niches greatly reduces its efficacy against complicated E. faecalis infections. To enhance the potency of Amp against different forms of E. faecalis infections, Amp was loaded into Lipid-Polymer hybrid Nanoparticles (LPNs), a highly efficient nano delivery platform consisting of a unique combination of DOTAP lipid shell and PLGA polymeric core. The antibacterial activity of these nanoparticles (Amp-LPNs) was investigated in a protozoa infection model, achieving a much higher multiplicity of infection (MOI) compared with studies using animal phagocytes. A significant reduction of total E. faecalis was observed in all groups receiving 250 μg/mL Amp-LPNs compared with groups receiving the same concentration of free Amp during three different interventions, simulating acute and chronic infections and prophylaxis. In early intervention, no viable E. faecalis was observed after 3 h LPNs treatment whereas free Amp did not clear E. faecalis after 24 h treatment. Amp-LPNs also greatly enhanced the antibacterial activity of Amp at late intervention and boosted the survival rate of protozoa approaching 400%, where no viable protozoa were identified in the free Amp groups at the 40 h postinfection treatment time point. Prophylactic effectiveness with Amp-LPNs at a concentration of 250 μg/mL was exhibited in both bacteria elimination and protozoa survival toward subsequent infections. Using protozoa as a surrogate model for animal phagocytes to study high MOI infections, this study suggests that LPN-formulated antibiotics hold the potential to significantly improve the therapeutic outcome in highly complicated bacterial infections.