Physiological and histopathological alterations in male Swiss mice after exposure to titanium dioxide (anatase) and zinc oxide nanoparticles and their binary mixture

Existing studies have shown the systemic damage of titanium dioxide (TiO2) or zinc oxide (ZnO) nanoparticles (NPs), but there is little or no existing knowledge on the potential adverse toxic effects of the mixture of the two. In order to investigate thein vivotoxic effect of the mixture of TiO(2)NPs and ZnO NPs, the acute toxicities of TiO(2)NPs, ZnO NPs by themselves, and their mixture (1:1) were determined. The systemic toxicities of the individual NPs and mixture were evaluated in mice using hematological indices, hepatic, renal, and lipid profile parameters, and histopathology as endpoints. NPs were intraperitoneally administered at doses of 9.38, 18.75, 37.50, 75.00, and 150.00 mg/kg bw each. Individual NPs and their mixture were administered daily for 5 and 10 d, respectively. The LD(50)of ZnO NPs was 299.9 mg/kg while TiO(2)NPs by themselves or TiO(2)NPs + ZnO NPs were indeterminate due to the absence of mortality of the male mice treated. TiO(2)NPs, ZnO NPs by themselves and TiO(2)NPs + ZnO NPs induced significant alterations in the hematological and biochemical parameters, with higher toxicity at 10 d. Histopathological lesions were observed in the liver, kidneys, spleen, heart, and brain of mice treated with the individual NPs and their mixture. TiO(2)NPs + ZnO NPs were able to induce a higher systemic toxicity than TiO(2)NPs or ZnO NPs individually. Our data suggest that more comprehensive risk assessments should be carried out on the mixture of NPs before utilization in consumer products.

Automated summary

The study investigated the in vivo toxic effect of a mixture of TiO(2)NPs and ZnO NPs, revealing that the mixture induced a higher systemic toxicity than when TiO(2)NPs or ZnO NPs were used individually. Comprehensive risk assessments should be carried out on NP mixtures before their utilization in consumer products.