Comparative study on chronic effects of nanoparticles and bulk TiO2 in gill, liver and intestine tissues of Zebrafish (Danio rerio)

The aim of the present study is to compare the effects of titanium dioxide in nano scale and bulk form in gill, liver and intestine tissues of zebrafish (Danio rerio). In this study About 150 zebrafish exposed to static-renewal condition of TiO2 particles treatment. These nanoparticles and bulk titanium dioxide in concentrations of 1 and 10 mg.l-1 and a blank group in three replicate for 30 days. After the period of treatment (30 days) the fishes were stabilized in formalin and stained for further classic Histological studies. The results indicated that TiO2 in nanoscale and bulk forms can result in   epithelium separation, edema, hyperplasia, adhesion in lamella and Hyperemia, hypertrophy in filament of zebrafish (Danio rerio).  Also  abnormalities as cytoplasmic vacuolization, increase of melanomacrophage centers,  congestion and hepatocyte degeneration were observed in liver and injuries such as epithelium separation, increased and inflammation of goblet cells, necrosis and hyperemia in intestine tissue of zebrafish. The findings also suggested that nanoparticles induced more severe abnormalities in comparison with their bulk counterparts. Also, most of the mentioned abnormalities are dependent to the materials concentration. So, the severity of abnormalities was highest at 10 mg.l-1 concentration of the titanium dioxide nanoparticles compared with other treatments.