Nanopartículas de prata para utilização como agente antimicrobiano em blendas de amido e poli (álcool vinílico)

Abstract

Nanoparticles are in an area of growing interest of nanoscience and nanotechnology, since they have unique properties as good conductivity, surface plasmon resonance, high catalytic effect, higher surface area and excellent antimicrobial activity. Several studies have been conducted with the purpose of synthesizing nanoparticles using non-toxic chemicals, environmentally benign solvents and renewable materials. The aims of this study were to obtain silver nanoparticles (Ag-NPT) using cassava starch and chitosan as reducing and stabilizing agents and incorporate them into membranes of starch /polyvinyl alcohol (PVA) blends. The physicochemical and morphological properties of nanoparticles and membranes were determined as well as their antimicrobial activity against strains of bacteria and fungi. The formation of nanoparticles was confirmed by the presence of surface plasmon band observed in the UV-visible spectrum. The silver nanoparticle with chitosan (Ag-NC) showed the greatest stability in solution and a more crystalline structure than the sample with starch (Ag-NS). The change in frequency and shape of the main vibration bands observed in the infrared spectra confirmed the interaction of silver with reducing groups present in the structure of chitosan and starch. The microscopy and EDS analyzes have allowed observing the presence, morphology and concentration of the silver nanoparticles as well as of the membranes. The micrographs of silver nanoparticles embedded in the membranes showed that silver was found evenly distributed in the same. The crystalline pattern of films increased with the addition of nanoparticles. Both nanoparticles and membranes showed antimicrobial activity against bacteria and fungi and the best results were obtained when the Ag-NC nanoparticle was added in the membrane. These results suggest a possible use of silver nanoparticles in polymer matrices to obtain dressings that inhibit the proliferation of these microorganisms in infections.