Toxic Effects of TiO₂ NPs on Zebrafish.

Tianle Tang,Zhang Zhang,Xiaopeng Zhu

doi:10.3390/ijerph16040523

Abstract

Titanium dioxide nanoparticles (TiO2 NPs) have become a widely used nanomaterial due to the photocatalytic activity and absorption of ultraviolet light of specific wavelengths. This study investigated the toxic effects of rutile TiO2 NPs on zebrafish by examining its embryos and adults. In the embryo acute toxicity test, exposure to 100 mg/L TiO2 NPs didn’t affect the hatching rate of zebrafish embryos, and there was no sign of deformity. In the adult toxicity test, the effects of TiO2 NPs on oxidative damage in liver, intestine and gill tissue were studied. Enzyme linked immunosorbent assay (ELISA) and fluorescence-based quantitative real-time reverse transcription PCR (qRT-PCR) were used to detect the three antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT) and glutathione S transferase (GSTs) in the above mentioned zebrafish organs at protein and gene levels. The results showed that long-term exposure to TiO2 NPs can cause oxidative damage to organisms; and compared with the control group, the activity of the three kinds of enzyme declined somewhat at the protein level. In addition, long-term exposure to TiO2 NPs could cause high expression of CAT, SOD and GSTs in three organs of adult zebrafish in order to counter the adverse reaction. The effects of long-term exposure to TiO2 NPs to adult zebrafish were more obvious in the liver and gill.

Highlights

TiO2 can form a nanocrystalline structure with a high specific surface area, i.e., titanium dioxide nanoparticles (TiO2 NPs)
3, the activityOf of Zebrafish three enzymes related to antioxidant damage (SOD, CAT and glutathione S transferase (GSTs)) in gill tissue of adult zebrafish growing for 7 days in different concentrations of
Compared with the blank control group and the and GSTs) in gill tissue of adult zebrafish growing for 7 days in different concentrations of TiO2 NPs conventional TiO2 group, the activities of three enzymes were decreased, especially in the high exposure solution was measured

Summary

Introduction

TiO2 can form a nanocrystalline structure with a high specific surface area, i.e., titanium dioxide nanoparticles (TiO2 NPs). With the photocatalytic activity and ultraviolet absorption activity at specific wavelengths, TiO2 NPs have become a widely used nanomaterial, especially in the cosmetics industry [1]. TiO2 , TiO2 NPs present better transparency on human skin and are largely used in cosmetic products like sunblock etc. TiO2 NPs reaches 2000 ton in 2009 in the United States, among which 65% has been used in cosmetics and sunblock [2]. As TiO2 NPs have antibacterial and organic catalytic functions, they can be used for sterilization and the degradation of organisms, as well as in other industries like inks and self-cleaning ceramics, glass, paint, and papermaking [3].The yearly demand of nano-TiO2 particles is estimated to hit 2.5 × 106 tons by 2025 in the United States [4]. The increasing manufacture and incorporation of nano-TiO2 in various applications will inevitably lead to release into the environment, causing pollution and imposing a potential hazard to ecological safety

Methods

Results

Conclusion