resumo
Layered double hydroxides (LDHs) are stimuli-responsive anionic nanoclays. The vast possibilities of using LDHs can lead to their existence in the ecosystem, raising a question of potential ecological concern. However, little is known about the effect of these nanomaterials on freshwater organisms. The present study aimed to assess the ecotoxicological effects of Zinc-Aluminium LDH-nitrate (Zn-Al LDH-NO3) in zebrafish (Danio rerio) early life stages. The endpoints measured were mortality, malformations and hatching rate after exposure of D. rerio embryos and larvae to Zn-Al LDH-NO3 following the OECD 236 guideline. The behavioral, biochemical (markers of oxidative stress and neurotoxicity), and molecular (at DNA level) alterations were also assessed using sub-lethal concentrations. No observable acute effects were detected up to 415.2 mg LDH/L while the 96 h-LC50 was estimated as 559.9 mg/L. Tested LDH caused malformations in D. rerio embryos, such as pericardial edema, incomplete yolk sac absorption and tail deformities (96 h-EC50 = 172.4 mg/L). During the dark periods, the locomotor behavior in zebrafish larvae was affected upon Zn-Al LDH-NO3 exposure. However, no significant biochemical and molecular changes were recorded. The present findings suggest that Zn-Al LDH-NO3 can be regarded as a non-toxic nanomaterial towards D. rerio (E/LC50 > > 100 mg/L) although impairment of the locomotion behavior on zebrafish embryos can be expected at concentrations below 100 mg/L.
palavras-chave
DAPHNIA-MAGNA; NANOPARTICLES; TOXICITY; OXIDE; ZINC; ECOTOXICITY; NITRATE; METALS; ASSAY; LDH
categoria
Environmental Sciences & Ecology; Science & Technology - Other Topics
autores
Carneiro, D; Damasceno, EP; Ferreira, V; Charlie-Silva, I; Tedim, J; Maia, F; Loureiro, S; Martins, R; Pavlaki, MD
nossos autores
João Tedim
Professor associado
Roberto Carlos Domingues Martins
Bolseiro de pós-DoutoramentoProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This project was carried out in the framework of the projects NANOGREEN (CIRCNA/BRB/0291/2019) funded by national funds (OE) through FCT (Fundacao para a Ciencia e a Tecnologia, I.P.) and the bilateral project EMPHASIS (PTDC/CTA-AMB/31180/2017), funded by FEDER, through COMPETE2020-Programa Operacional Competitividade e Internacionalizacao (POCI), and by national funds (OE), through FCT/MCTES and (#2018/07098-0 #19/19939-1) through the Sao Paulo Research Foundation-FAPESP. Evila Pinheiro Damasceno received a Ph.D. grant (PD/BD137978/2018) through the BEGC-Biology and Ecology of Global Changes Ph.D. program financed by the Portuguese Science and Technology Foundation-FCT (Fundacao para a Ciencia e Tecnologia). Roberto Martins is funded by national funds (OE), through FCT (grant 2021.00386.CEECIND). We acknowledge the financial support to CESAM (UIDP/50017/2020 + UIDB/50017/2020 + LA/P/0094/2020) and to CICECO-Aveiro Institute of Materials (UIDB/50011/2020, UIDP/ 50011/2020 & LA/P/0006/2020), by FCT/MCTES through national funds.