EVALUATION OF TOXICITY OF SILVER NANOPARTICLES SINTETIZED BY BIOLOGICAL MEDIATORS

FERNÁNDEZ G; RABA J; FERNÁNDEZ BALDO MA; SANZ FERRAMOLA MI; SALINAS E

Mendoza

Congreso; XXXVI REUNIÓN CIENTÍFICA ANUAL DE LA SOCIEDAD DE BIOLOGÍA DE CUYO; 2018

Sociedad de Biología de Cuyo

Nanotechnology is a rapidly developing area that can have substantial impacts on the economy, society and the environment. In recent years, silver nanoparticles (AgNPs) have been studied for their antimicrobial capacity and their possible applications to the food industry. This is why it is necessary to monitor the toxic potential of nanoparticles. Plants have been used as indicators of toxicity because they have a variety of well-defined biological parameters. The objective of this work was to study the possible toxic and genotoxic effects of AgNPs synthesized by biological mediators (biosynthesis) such as Aspergillus niger (AgNPs-A.n), Cryptococcus laurentii (AgNPs-C.l) and Rhodotorula glutinis (AgNPs-R.g), on plants. To measure the toxicity effects of the AgNPs, standardized bioassays were performed using Lactuca sativa (lettuce) seeds. Ten seeds were placed in a Petri dish with filter paper in the bottom as a support and then, 2.5 mL of each treatment: 1-AgNPs-A.n, 2-AgNPs-C.l, 3-AgNPs-R.g, and 4-AgNPs-chem (AgNPs by chemical synthesis), adjusted at concentration of 3 mg.mL-1 was added. Distilled water as negative control and Cu+ 2 solutions (5 mg.mL-1) as positive control were used. After 5 days of incubation at 25 ± 1°C, the germination percentage (G%) and the root length were determined. To measure the genotoxicity effects of the AgNPs, bioassays using onion (Allium cepa) roots were performed. Each onion bulb was placed in aerated cuvettes and four bulbs of uniform size (3 cm diameter) were used per treatment. The previously mentioned treatments 1, 2, 3 and 4 were applied, while dechlorinated water and Griseofulvin solution (250 mg.mL-1) were used as negative and positive controls, respectively. The bulbs were partially submerged and after 30 h of exposure, cells were observed to identify the following parameters: mitotic index and chromosomal aberrations. In the toxicity tests, our results showed no significant differences of G% and root length among L. sativa seeds treated with different biosynthesized AgNPs or when they were compared to the negative control; whereas significant differences among AgNPs-chem and the positive control were observed. In genotoxicity analysis, taking into account the Allium cepa mitotic index, no significant differences of AgNPs-A.n, AgNPs-C.l and AgNPs-R.g treatments when compared to the negative control were observed; meanwhile, AgNPs-chem and Griseofulvin treatments presented significant differences. In contrast, considering chromosomal aberrations, all the treatments presented significant differences compared to the negative control, except for AgNPs-R.g treatment.. We can conclude that the biosynthesized AgNPs did not show toxicity. In the case of the Allium cepa assays, AgNPs-R.g. was not genotoxic and although AgNPs-A.n and AgNPs-C.l showed some genotoxicity degree, it was lower than that of AgNPs-chem and the positive control. We can conclude that AgNPs derived of biological synthesis might be used as antimicrobials applied to the food sector.