Two dimensional TiO2 nanosheets: in vivo toxicity investigation

Titanium dioxide (TiO2) nanosheets have received attention for photodynamic therapy due to their unique electronic structure and high surface activity. However, the biological response and toxicity of two dimensional (2D) nanomaterials are still not clear. Herein, in vivo toxicity of TiO2 nanosheets, such as biodistribution, hematology, biochemistry and pathology, were evaluated at the dose of 10 mg kg(-1) by intraperitoneal injection for up to 30 days. It was found that TiO2 could gradually accumulate in the liver and spleen with increase of exposure time, which is due to large size induced absorption from the reticuloendothelial system (RES). Furthermore, the hematological data indicated that no significant difference was found. However, the biochemistry showed that the liver indicator, AST, presented a significant difference after 30 days compared with control mice. The present work revealed that 2D TiO2 nanosheets did not cause appreciable toxicity, but induced accumulation in the liver and slight abnormality of the liver with increasing exposure time.