Zn-Al layered double hydroxides induce embryo malformations and impair locomotion behavior in Danio rerio

• Published in: NanoImpact Vol. 30; p. 100457
• Main Authors: Carneiro, Diana, Damasceno, Évila Pinheiro, Ferreira, Violeta, Charlie-Silva, Ives, Tedim, João, Maia, Frederico, Loureiro, Susana, Martins, Roberto, Pavlaki, Maria D.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2023
• Subjects: Animals; Ecosystem; Embryo, Nonmammalian - abnormalities; Embryotoxicity; Engineered nanoclays; Locomotion; Stimuli-responsive nanomaterials; Sub-lethal effects; Zebrafish; Zebrafish - abnormalities; Zinc - pharmacology; Embryotoxicity; Zebrafish; Sub-lethal effects; Engineered nanoclays; Stimuli-responsive nanomaterials
• ISSN: 2452-0748; 2452-0748
• DOI: 10.1016/j.impact.2023.100457

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 (ZnAl 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 ZnAl 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 ZnAl LDH-NO3 exposure. However, no significant biochemical and molecular changes were recorded. The present findings suggest that ZnAl 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. [Display omitted] •ZnAl LDH cause lethality in zebrafish at high exposure concentrations (LC50 = 559.9 mg/L).•ZnAl LDH cause embryo malformations (e.g. pericardial edema; EC50 = 172 mg/L).•Low ZnAl LDH exposure concentrations (8.9 mg/L) induce behavioral changes.•No oxidative stress, neurotoxicity or genotoxicity was detected in Zn-AL LDH exposures.