title: Photocatalytic and phototoxic properties of TiO2-based nanofilaments: ESR and AFM assays.
abstract: There is uncertainty in understanding of the relationship between physico-chemical parameters of nanosized titanium dioxide (nano-TiO(2)) 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 TiO(2)-based nanowires (TiO(2)-NWs). We employed electron spin resonance (ESR) to detect reactive oxygen species (ROS) generated in aqueous suspensions of TiO(2)-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 TiO(2)-NWs and Degussa P25. High-resolution AFM surface topography and cell elasticity measurements revealed toxic effects both in cells incubated with TiO(2)-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-TiO(2) and cell toxicity.
authors: Laboratory of Complex Matter Physics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors: Katarzyna
authors: K
authors: Pierzchała
authors: Małgorzata
authors: M
authors: Lekka
authors: Arnaud
authors: A
authors: Magrez
authors: Andrzej J
authors: AJ
authors: Kulik
authors: László
authors: L
authors: Forró
authors: Andrzej
authors: A
authors: Sienkiewicz
mesh_terms: D002384:Catalysis; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000633:toxicity*; D018384:Oxidative Stress; D055668:Photochemical Processes; D014025:Titanium / Q000633:toxicity*
chemical_list: C009495:titanium dioxide; D014025:Titanium