Bioconcentration, depuration and toxicity of Pb in the presence of titanium dioxide nanoparticles in zebrafish larvae.

The interactions between nanoparticles (NPs) and metals in aquatic environments may modify the bioavailability and toxicity of metals to organisms. In this study, we investigated the effects of titanium dioxide NPs (n-TiO₂) on the bioconcentration, depuration, and neurotoxic effects of lead (Pb) in zebrafish larvae. Transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy showed that Pb²⁺ was adsorbed by n-TiO₂ to form NP-Pb complexes in suspension, and these complexes were observed in larval tissues. The bioconcentration of Pb in larvae along with the depuration rates of Pb were higher in the presence of n-TiO₂ compared to when n-TiO₂ was absent. Exposure to Pb alone induced the expression of the biomarker metallothionein, downregulated neurodevelopment-related genes, and reduced swimming activity of larvae. However, the addition of n-TiO₂ to the exposure solution alleviated these effects. The results suggest that n-TiO₂ can act as a carrier of Pb to increase its bioconcentration; however, the formation of NP-Pb complexes likely reduces the amount of free Pb²⁺, thereby reducing toxicity to larvae.

KEYWORDS: {{ getKeywords(articleDetailText.words) }}