Oxidative and Binding Effect of Nano-TiO2 on Plasmid DNA and Pepsin

Abstract

With the development of nano material industry, more and more attention has been paid on the biological effect of nano materials. However, little research focused on the effect of nano TiO 2 on protein level. In this study, we detected the toxic effect of nano TiO 2 (50~60nm) on DNA and functional proteinase. The oxidative damage of nano TiO 2 on DNA was detected by gel electrophoresis and HPLC. Anson method was used to study the inhibition of nano TiO 2 on pepsin, and the mechanism of the reaction was further researched by the method of UV-Vis scan and TEM. The results showed that the ratio of super-coiled DNA decreased significantly both under UV radiation and visible light. Levels of 8-OHdG generated from DNA increased from 27.66 8-OHdG/10 4 dG to 296.69 8-OHdG/10 4 dG after treated with nano TiO 2 . After water incubated with nano TiO 2 at 37 , the activity of pepsin decreased with the increase of the concentration of particels, UV-Vis scan and TEM detection proved the binding effect of nano TiO 2 on pepsin, which indicated potential usage for oral drug delivery of nano TiO 2 .

Effect of nanostructured TiO2 crystal phase on photoinduced apoptosis of breast cancer epithelial cells

“…Previous studies in various animal and human cell lines demonstrated that TiO 2 nanoparticles generate a large amount of hydroxyl free radicals, thereby leading to DNA damage 41,42. It has been proposed that the genotoxicity of metals and metal oxides results from the indirect formation of ROS.…”

Cytotoxic, genotoxic and the hemolytic effect of titanium dioxide (TiO2) nanoparticles on human erythrocyte and lymphocyte cells in vitro

“…() reported that TiO 2 nanoparticles enhance photocatalysis, oxidative stress, DNA adducts, DNA strand breaks and chromosome damage. Earlier reports in animal cells have also suggested that TiO 2 nanoparticles generate a large amount of hydroxyl free radical thereby leading to DNA damage (Reeves et al ., ; Zhu et al ., ; Ghosh et al ., ). In our study, the DCFHDA assay in human lymphocyte cells also suggested a significant increase in ROS generation with an increase in treatment concentration.…”