G.C. Leal, Marcos A. Gelesky, Leandro Machado de Carvalho, Daniela Fernandes Ramos, Jimena Cazenave, Analía Ale, Caroline Pires Ruas, A. Ayech, Marcelo Estrella Josende, Juan Manuel Galdopórpora, José Maria Monserrat, M. Duarte, Martín F. Desimone, Priscila Cristina Bartolomeu Halicki, and Juliane Ventura-Lima
In recent times, however, due to the emergence of bacterial strains with resistance to conventional antibiotics, silver has again gained attention as an alternative for developing new efficient bactericides, including the use of silver nanoparticles (AgNPs). However, the improper disposal of these items after use may cause toxicological effects on organisms in the environment. To evaluate the potential environmental hazard of nanosilver-coated dressings, the nematode Caenorhabditis elegans was chosen as a test organism. The assays were conducted in 24-well plates that contain four different sizes of coated dressing to obtain different concentrations. L1 and L4 C. elegans larval stages were exposed to these nanosilver concentrations. Dressing cutouts were arranged between two layers of agar for 3 days and Escherichia coli (OP 50 strain) was added as food source for the worms. After the exposure period, growth, reproduction, fertility, silver concentration in the medium and the concentration of reactive oxygen species (ROS) in the worms were evaluated. Scanning and transmission electron microscopy analyses were performed on the coated dressings, as well as analyses of zeta potential, ionic release and antibacterial power in two bacterial strains (Pseudomonas aeruginosa and Staphylococcus aureus). It was verified the antibacterial power of the coated dressing, in both bacteria strains tested. Characterization of the coated dressing indicated heterogeneous nanoparticles, as well as distinct zeta potentials for the medium in water and saline medium (0.9% NaCl). L1 larval worms exposed to nanosilver-coated dressing showed a high ROS concentration and reductions in growth, fertility and reproduction. Worms exposed to the coated dressing during the L4 stage showed almost no response. Overall, the obtained results indicate the potential environmental hazard of nanosilver-coated dressings. Fil: Ayech, Alinne. Universidade Federal do Rio Grande; Brasil Fil: Josende, M. E.. Universidade Federal do Rio Grande; Brasil Fil: Ventura Lima, J.. Universidade Federal do Rio Grande; Brasil Fil: Ruas, Caroline Pires. Universidade Federal do Rio Grande; Brasil Fil: Gelesky, M. A.. Universidade Federal do Rio Grande; Brasil Fil: Ale, Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Cazenave, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Galdopórpora, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Instituto de Química y Metabolismo del Fármaco; Argentina Fil: Desimone, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Instituto de Química y Metabolismo del Fármaco; Argentina Fil: Duarte, Miriam. Universidade Federal do Rio Grande; Brasil Fil: Halicki, Priscila Cristina Bartolomeu. Universidade Federal do Rio Grande; Brasil Fil: Ramos, Daniela Fernandes. Universidade Federal do Rio Grande; Brasil Fil: Carvalho, L. M.. Universidade Federal de Santa Maria; Brasil Fil: Leal, Gabriela Camera. Universidade Federal de Santa Maria; Brasil Fil: Monserrat, José María. Universidade Federal do Rio Grande; Brasil