Effects of Cu x TiO y nanometer particles on biological toxicity during zebrafish embryogenesis

Abstract

This study investigated the toxicity of Cu (1, 10, 15, and 25 mol%) loaded TiO2 and pure TiO2 nanometersized photocatalysts during the development of zebrafish embryogenesis. The hatch rate decreased in the Cu x TiO y nanoparticles exposed groups (10, 20 ppt) compared to pure TiO2 nano-particles (10, 20 ppt) exposed or control groups. These Cu x TiO y and TiO2 nanoparticles led to developing mutated embryos with abnormal notochord formation, no tail, damaged eyes and abnormal heart development. Exposure to Cu x TiO y and pure TiO2 nanoparticles led to glutathione increase, catalase activity increase, GST increase and GSR increase than control. Penetration of the Cu x TiO y and pure TiO2 nanoparticles to the embryo was also tested. It was observed that Cu x TiO y and pure TiO2 nanoparticles penetrated into cells. Moreover Cu x TiO y penetrated into the skin, nerve and yolk sac epithelium cells on the zebrafish larvae as aggregated particles, which may induce the direct interaction between nanoparticles and cell to cause adverse biological responses. As a result, the Cu-loaded TiO2 nanoparticles had the toxicity of zebrafish embryo and larvae in the water environment.