Síntese e caracterização de nanopartículas de prata incorporadas em nanocelulose bacteriana para utilização como agente antimicrobiano

Abstract

Microorganisms are essential for life on earth and therefore their beneficial and harmful actions have been studied over the years, só techniques and substances have been developed to control them; however, its resistance and adaptability have become a growing public health problem, which requires actions to prevent future damage. Thinking about it with the advent of nanoscience, it was discovered that the combination of materials at the nanometric scale allows us to explore and create nanocomposites with unique properties. Therefore, this work sought to develop nanocomposites composed of bacterial nanocellulose from the bacteria Komagataeibacter hansenii with the incorporation of silver nanoparticles as an antimicrobial agent to control harmful microorganisms and provide a disinfectant action. Bacterial nanocellulose with silver nanoparticles can be used to inhibit microbial action and reduce contamination in biologically exposed areas, minimizing risks to human health, thus mitigating the problem of cross contamination, among others. The nanocomposites were produced by impregnating previously synthesized silver nanoparticles, or by impregnating silver cations in bacterial nanocellulose (wet and dry), and were characterized by scanning and transmission electron microscopy and biological tests were performed with four strains : S. aureus (Gram-positive), E. coli (Gram-negative), P. aeruginosa (Gram-negative) and E. faecalis (Gram-positive). The membranes presented morphology and structures different from those commonly seen in the literature, with images as if they were scales. The dry membranes, both produced In situ or Ex situ, showed low biocidal action, as well as the samples made in toluene, while the wet membranes and with a higher concentration of silver showed better results in relation to antimicrobial action, as well as a higher content. Of silver nanoparticles (regardless of concentration), incorporated and/or adhered to them, when compared to dry samples, the wet ones showing better response, even more against the P. aeruginosa bacteria, however, both can be used in several applications, Mainly for food protection.