Photocatalytic and phototoxic properties of TiO2-based nanofilaments: ESR and AFM assays

• Published in: Nanotoxicology Vol. 6; no. 8; pp. 813 - 824
• Main Authors: Pierzcha a, Katarzyna, Lekka, Ma gorzata, Magrez, Arnaud, Kulik, Andrzej J., Forró, László, Sienkiewicz, Andrzej
• Format: Journal Article
• Language: English
• Published: England Informa UK, Ltd 01.12.2012; Taylor & Francis
• Subjects: atomic force microscopy; Catalysis; Cell Line, Tumor; cell protein staining; Cell Survival - drug effects; Electron spin resonance; Electron Spin Resonance Spectroscopy; Humans; Microscopy, Atomic Force; Microscopy, Electron, Transmission; nano-engineered materials, titanium dioxide (TiO; Nanostructures - toxicity; nanotoxicity; Oxidative Stress; Photochemical Processes; reactive oxygen species; Titanium - toxicity
• ISSN: 1743-5390; 1743-5404
• DOI: 10.3109/17435390.2011.625129

Abstract There is uncertainty in understanding of the relationship between physico-chemical parameters of nanosized titanium dioxide (nano-TiO2) and its toxicity when brought into contact with living cells. This study provides a multidisciplinary experimental insight into the toxicity and phototoxicity of the custom-made TiO2-based nanowires (TiO2-NWs). We employed electron spin resonance (ESR) to detect reactive oxygen species (ROS) generated in aqueous suspensions of TiO2-NWs and combined these results with atomic force microscopy (AFM) to trace the onset of toxic effects towards human melanoma cells. The cells were treated with low concentrations (∼2.5 μg/ml) of TiO2-NWs and Degussa P25. High-resolution AFM surface topography and cell elasticity measurements revealed toxic effects both in cells incubated with TiO2-NWs in the dark and exposed to the photo-oxidative stress under UVA radiation. In contrast to ROS generation efficacy in the absence of cells in vitro, no direct correlation was found between the physical parameters of nano-TiO2 and cell toxicity.