Synergistic Antimicrobial Effects of Silver/Transition-metal Nanoparticle Combinatorial Treatments

J.R. Morones Ramirez
Universidad Autonoma de Nuevo Leon,

Keywords: nanoparticles, antimicrobial activity, transition metals, synergistic effect


Due to the emergence of multi-drug resistant strains, the development of novel antibiotics has become a critical issue. One promising approach is the use of transition metal nanoparticles, since they exhibit rapid and significant toxicity, at low concentrations, in prokaryotic cells. Nevertheless, one of the biggest drawbacks with metallo-pharmaceuticals is their toxicity in eukaryotic cells. Therefore, in this work we gathered literature information to find non-toxic doses of the individual metal nanoparticles and hypothesized that at lower doses and in combination with silver nanoparticles, the barriers to use them as therapeutic agents would be mitigated. This work demonstrates that there is a synergistic antimicrobial activity effect between silver nanoparticles and nanoparticles from transition metal including: Zn, Cd, Ni, and Cu. The combinatorial treatments exhibited a synergistic 500-fold increased bactericidal effect compared to their individual metal components. Moreover, such combinations allowed for a synergistic 4-fold decrease in the silver nanoparticle minimum inhibitory concentration. The results reported in this work suggest that the increased antimicrobial activity of combinatorial treatments based on transition metal nanoparticles and silver nanoparticles will play an important role in the future development of antimicrobial agents and treatments against infections.