Enrofloxacin-Impregnated PLGA Nanocarriers for Efficient Therapeutics and Diminished Generation of Reactive Oxygen Species

Enrofloxacin, a third-generation fluoroquinolone drug, commonly used for Gram-negative bacterial infection treatment, was entrapped in poly­(lactic-co-glycolic acid) nanoparticles. This was accomplished via the use of a single-emulsion evaporation method. Synthesized nanoparticles presented an average size of 102 ± 6 nm, a zeta potential of −32 ± 3 mV, and a (PDI) polydispersity index of 0.095 ± 0.02. Drug loading and entrapment efficiency in the nanoparticles were found to be 14.1 ± 2.7 μg/mg and 43.8 ± 8.3%, respectively. Release of the drug from the nanoparticle was biphasic, and 96% of the drug was released over 4.2 days. The nanoparticle loaded enrofloxacin demonstrated good antimicrobial activity against E. coli and S. aureus. The cytotoxicity evaluation was performed by introducing a free and nanodelivered drug against IPEC-J2 cells. The drug entrapped nanoparticles demonstrated lower toxicity to mammalian cells relative to a free drug. The toxicity of free enrofloxacin was caused mainly by ROS production. Incorporation of the drug into the PLGA matrix minimized ROS production by the antibiotic. In summary, the synthesized loaded nanoparticle with antibiotic reduced its innate cell toxicity and at the same time retained its antimicrobial efficacy.