Biocompatibilidade de nanocristais de óxido de zinco dopados com cobre em Drosophila melanogaster

Abstract

Zinc oxide nanoparticles have a wide range of radiation absorption, high photostability and chemical stability, being considered excellent bactericides. Zinc oxide (ZnO) is a food additive considered safe in low concentrations, however the pure substance can lead to cytotoxicity through the release of Zn²+ ions. The doping of nanoparticles (NPs) brings advantages by reducing possible negative effects as they modify the structure of NPs, in order to improve their performance. In the present study, the zinc oxide nanoparticle was doped with the copper transition metal. Thus, the aim was to investigate the biocompatibility of ZnO NPs doped with 0.4% copper, using Drosophila melanogaster as an in vivo model. The animals were exposed to final concentrations of 0.00 to 2.00 mg/mL of pure ZnO NPs or doped with 0.4% copper. Mortality, cytotoxicity and longevity rates were evaluated after exposing the animals to substances orally. It was observed that flies exposed to pure ZnO suffered from a high rate of larval death, a low number of formed pupae and animals that reached the adult stage, completing the development cycle. Such negative impacts were significantly reduced with the doping of NPs with copper. Therefore, the presence of copper in the samples of ZnO NPs contributed significantly to the improvement of the biocompatibility of these NPs, increasing the survival rate of the animals and decreasing the observed cytotoxicity. The data obtained in the present work will contribute to the understanding of the toxicological profile of zinc oxide NPs, and may also support further studies related to the toxicity of the substances tested here.