Comparison of Oxidative Stresses Mediated by Different Crystalline Forms and Surface Modification of Titanium Dioxide Nanoparticles

Titanium dioxide nanoparticles (TiO₂ NPs) are manufactured worldwide for use in a wide range of applications. There are two common crystalline forms of TiO₂ anatase and rutile with different physical and chemical characteristics. We previously demonstrated that an increased DNA damage response is mediated by anatase crystalline form compared to rutile. In the present study, we conjugated TiO₂ NPs with polyethylene glycol (PEG) in order to reduce the genotoxicity and we evaluated some oxidative stress parameters to obtain information on the cellular mechanisms of DNA damage that operate in response to TiO₂ NPs different crystalline forms exposure in hepatocarcinoma cell lines (HepG2). Our results indicated a significant increase in oxidative stress mediated by the anatase form of TiO₂ NPs compared to rutile form. On the other hand, PEG modified TiO₂ NPs showed a significant decrease in oxidative stress as compared to TiO₂ NPs. These data suggested that the genotoxic potential of TiO₂ NPs varies with crystalline form and surface modification.