Synergistic bactericidal combinations between gentamicin and chitosan capped ZnO nanoparticles: A promising strategy for repositioning this first-line antibiotic

SCOLARI, I. R.; PÁEZ, P. L .; GRANERO, G. E.

Heliyon

Elsevier Ltd

Año: 2024 vol. 10

Gentamicin (GEN), a widely used broad-spectrum antibiotic, faces challenges amid the globalemergency of antimicrobial resistance. This study aimed to explore the synergistic effects of zincoxide nanoparticles (ZnO NPs) in combination with GEN on the bactericidal activity againstvarious bacterial strains. Results showed ZnO NPs with MICs ranging from 0.002 to 1.5 μg/mL,while the precursor salt displayed a MIC range of 48.75–1560 μg/mL. Chitosan (CS)-capped ZnONPs exhibited even lower MICs than their uncapped counterparts, with the CS-capped synthesizedZnO NPs demonstrating the lowest values. Minimal bactericidal concentrations (MBC) alignedwith MIC trends. Combinations of CS-capped synthesized ZnO NPs and GEN proved highlyeffective, inhibiting bacterial growth at significantly lower concentrations than GEN or ZnO NPsalone. This phenomenon may be attributed to the conformation of CS on the ZnO NPs’ surface,enhancing the positive particle surface charge. This possibly facilitates a more effective interaction between ZnO NPs and microorganisms, leading to increased accumulation of zinc and GENwithin bacterial cells and an overproduction of reactive oxygen species (ROS). It’s crucial to notethat, while this study did not specifically involve resistant strains, its primary focus remains onenhancing the overall antimicrobial activity of gentamicin. The research aims to contribute toaddressing the global challenge of antimicrobial resistance, recognizing the urgent need foreffective strategies to combat this critical issue. The findings, particularly the observed synergybetween ZnO NPs and GEN, hold significant implications for repositioning the first-line antibioticGEN