Avaliação do potencial antimicrobiano de nanopartículas de quitosana associadas ao ácido rosmarínico

Abstract

Microbial resistance arises from modifications in the genome of microorganisms that make them less susceptible to currently available drugs. The bacteria Staphylococcus aureus and Pseudomonas aeruginosa are listed as important microorganisms for antimicrobial resistance surveillance by the World Health Organization. Such resistance presents high morbidity and mortality, which leads to the search for new pharmacological agents from different natural sources. Thus, with few efficient drugs against bacterial agents, rosmarinic acid shows important properties, such as antibacterial action, which is still poorly explored. Chitosan is a polymeric macromolecule with antimicrobial activity. This compound has been increasingly recognized for this demand due, also, to low toxicity and controlled release of substances, especially for nanotechnology in the formation of nanoparticles. Therefore, the aim of this study is to evaluate the potentiation of the antimicrobial effect of the chitosan nanosystem associated with rosmarinic acid against Staphylococcus aureus ATCC and Pseudomonas aeruginosa ATCC. Initially, the reproducibility of the ionic gelation technique was evaluated through physicochemical characterization regarding size and polydispersity. The nanoparticles showed satisfactory average size between 125.6 nm and 184 nm with polydispersity between 0.381 and 0.525. The minimum inhibitory concentration was subsequently evaluated in a microplate. The results obtained showed inhibition capacity of the bacterial activity of Staphylococcus aureus in both associations explored in this work, but without activity against Pseudomonas aeruginosa. Thus, the nanosystem presented in this study can be considered a promising innovation for future studies in pharmacotherapy focused on bacterial infections.