Nano Biomedicine

Induction of Oxidative Stress in HeLa Cells with Reactive Oxygen Species Generated in Titanium Oxide Nano-tubes

Hisataka NISHIDA1, Tomonari TANAKA2, Yoshitomo HONDA3, Tomoyo GOTO1, Sunghun CHO1, and Tohru SEKINO1
1Department of Advanced Hard Materials, The Institute of Scientific and
Industrial Research (ISIR), Osaka University, Osaka, Japan
2Department of Biobased Materials Science, Graduate School of Science and Technology,
Kyoto Institute of Technology, Kyoto, Japan
3Institute of Dental Research, Osaka Dental University, Osaka, Japan

Nano Biomed 2016;8(1): 41-50, (June 30, Nano Biomedicine)

Since one of the potential applications of titanium oxide nano-tubes (TNT) is to photodynamic therapy (PDT), the effects of reactive oxygen species (ROS) generated by TNT irradiated with ultraviolet (UV) rays were evaluated in HeLa cells.
The microstructures of cells incubated in TNT-containing medium were observed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), and the adherence of TNT to these cells was confirmed. An oxidative stress fluorescence probe was then used to visualize oxidative stress in HeLa cells, and revealed that the ROS generated by TNT led to oxidative stress in HeLa cells. A flow cytometric analysis was performed to characterize the cell status and distinguish between viable and unviable cells. Polyethylene glycol (PEG) modifications to the surfaces of TNT effectively facilitated adherence to cells, and the UV irradiation of HeLa cells during their incubation in culture medium containing PEG-modified TNT induced oxidative stress, thereby suppressing DNA repair.

Key words: photodynamic therapy (PDT); Titania nanotube (TNT); reactive oxygen species (ROS)

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