Nano-sized CuO, TiO₂and ZnO affectXenopus laevisdevelopment

Abstract

The teratogenic potential of commercially available copper oxide (CuO), titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs) was evaluated using the standardized FETAX test. After characterization of NP suspensions by TEM, DLS and AAS, histopathological screening and advanced confocal and energy-filtered electron microscopy techniques were used to characterize the induced lesions and to track NPs in tissues. Except for nCuO, which was found to be weakly embryolethal only at the highest concentration tested, the NPs did not cause mortality at concentrations up to 500 mg/L. However, they induced significant malformation rates, and the gut was observed to be the main target organ. CuO NPs exhibited the highest teratogenic potential, although no specific terata were observed. ZnO NPs caused the most severe lesions to the intestinal barrier, allowing NPs to reach the underlying tissues. TiO₂ NPs showed mild embryotoxicity, and it is possible that this substance could be associated with hidden biological effects. Ions from dissolved nCuO contributed greatly to the observed embryotoxic effects, but those from nZnO did not, suggesting that their mechanisms of action may be different.

Toxicological aspects of photocatalytic degradation of selected xenobiotics with nano-sized Mn-doped TiO2

“…The authors suggest that TiO 2 NPs do not affect survival of X. laevis embryos, even at very high concentrations (Bacchetta et al, 2012;Birhanli et al, 2014). However, our results showed that Mn-doped TiO 2 NPs were slightly lethal in X. laevis embryos.…”

“…It is suggested that aggregation of TiO 2 NPs may play an important role in the adverse effects due to the size and shape of nanoparticles, and these characteristics may also determine their toxic potential (Sharma, 2009;Miseljic and Olsen, 2014). Recent data show that TiO 2 NPs may not be toxic or are slightly to moderately toxic to fish and amphibians (Hao et al, 2009;Bacchetta et al, 2012). Therefore, their indirect role on mortality and physiology in aquatic organisms, such as fish and amphibians, due to some interactions with different kinds of organic pollutants in aquatic ecosystems has come into greater prominence.…”

<em>Daphnia magna</em> and<em> Xenopus laevis</em> as in vivo models to probe toxicity and uptake of quantum dots functionalized with gH625

“…[21][22][23] In vivo experiments have been reported to further support the toxicity of MNPs (dysfunctions of the intestinal apparatus in embryonic zebra fish models, defects in the embryonic development of Xenopus laevis, phenotypic modifications in the progeny of Drosophila melanogaster and a decrease in body weight, red blood cells, hematocrit and DNA damage in mice). [24][25][26][27][28] The in vivo studies and the potential effects on public health and ecosystems are key to understanding the real applicability of a delivery strategy. Animal welfare, ethical issues and economics have rendered fundamental use of in vivo assays on invertebrates.…”

Perfluoroheptanoic acid affects amphibian embryogenesis by inducing the phosphorylation of ERK and JNK

“…Teratogenic effects are assessed by determining their influences on mortality, malformation, and growth inhibition, effects that clearly indicate developmental toxicity. This assay has been used to investigate teratogens and developmental toxicants that negatively affect human health and the ecosystem (18,19). FETAX is appropriate for the screening of chemicals (including nanomaterials), evaluating biotransformation, and can serve as a model of limb development.…”