Fibrous nanocomposites based on EVA40 filled with Cu nanoparticles and their potential antibacterial action

Nowadays, there is growing increase of plastics use in the world of food industry and medicine. In this context there is a need of, apart from conventional properties of plastics, minimizing growth of harmful microorganisms. In this article new polymer based materials are prepared, characterized and evaluated against their antibacterial action. New materials based on poly(ethylene-co-vinyl acetate) are prepared by solution blow spinning, SBS. Mats of nanocomposites constituted by micrometric fibers are obtained with compositions ranging from 0% to 6% by weight of Cu nanoparticles, CuNp. In order to understand the effect of the CuNp on the E. coli cell adhesion and biofilm formation, morphology, structure, thermal and surface properties of the nanocomposites are studied by several techniques. SBS allows preparing the nanocomposites with quite uniform dispersion of CuNp within the polymer. Neither the presence of CuNp nor the SBS process induce changes in the structure and in the thermo-degradation of EVA40. The presence of CuNp exerts antibacterial effect against the DH5α E. coli. There is a direct action of the CuNp on the extracellular polymeric substances and on the bacterial metabolism. CuNp also affect HaCaT cells growing, delaying the process at higher amounts of Cu but keeping their viability.