Toxicidade de nanopartículas de óxido de ferro (γ-Fe2O3) funcionalizadas com citrato ao longo do desenvolvimento inicial do zebrafish (Danio rerio)

• Autor(a) principal: Pereira, Aryelle Canedo
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/12472
• topic: Nanoecotoxicologia; Nanomateriais; Embriotoxicidade; Cardiotoxicidade; Biomarcadores; Nanoecotoxicology; Nanomaterials; Embryo; Cardiotoxicity; Biomarkers; CIENCIAS BIOLOGICAS::GENETICA::GENETICA HUMANA E MEDICA

Iron oxide nanoparticles (NOFs) are being increasingly used in medical, environmental and technological applications. However, with its growing production and application, concerns arise about its release into the environment and its impact on human and environmental health. In this sense, the zebrafish (Danio rerio) is proving to be an excellent model system for the analysis and classification of nanomaterial toxicity. Thus, the general objective of the present study was to evaluate the toxicity of NOFs (γ-Fe2O3 NPs) functionalized with citrate throughout the initial development of zebrafish, comparing toxicity with iron ions, after static and semi-static exposure. For this purpose, the zebrafish embryos were exposed in static (without medium renewal) and semi-static (medium renewal every 24 h) exposure modes to γ-Fe2O3 NPs functionalized with citrate and iron chloride in different concentrations environmentally relevant iron (0.3, 0.6, 1.25, 2.5, 5.0 and 10 mg L-1) for 144 h, together with the control group maintained in water reconstituted in 24-well plates. The results showed that γ-Fe2O3 NPs were accumulated mainly in the chorion of the embryos and in the digestive system and liver of zebrafish larvae. Γ-Fe2O3 NPs have low toxicity compared to iron ions, indicating that the in vivo toxicity of both forms of iron is mediated by different mechanisms of action. However, NPs caused significant changes after semi-static exposure causing a decrease in heart rate, induced blood accumulation and formation of pericardial edema in zebrafish embryos, indicating its cardiotoxic effect. Regarding the exposure method, it was observed that both forms of iron induced high embryotoxicity under semi-static exposure conditions compared to static exposure, indicating that the toxicity depends on the frequency of exposure. This was the first study on the impact of the exposure condition on the toxicity of γ-Fe2O3 NPs on the development of zebrafish.