Oxidative stress caused by TiO2 nanoparticles under UV irradiation is due to UV irradiation not through nanoparticles

In this study, we assessed the effect of TiO2-NOAAs for S. cerevisiae using DNA microarray. To compare yeast cells under various conditions, six treatment conditions were prepared (1. adsorbed fraction to TiO2-NOAA under UV; 2. non-adsorbed fraction to TiO2-NOAA under UV; 3. adsorbed fraction to TiO2-NOAA without UV; 4. non-adsorbed fraction to TiO2-NOAA without UV; 5. under UV; and 6. untreated control). The result of the DNA microarray analysis, suggested that yeast cells that are adsorbed by TiO2-NOAA under UV irradiation suffer oxidative stress and this stress response was similar to that by only UV irradiation. We concluded that the effect of TiO2-NOAAs on yeast cells under UV irradiation is not caused by TiO2-NOAA but UV irradiation.