title: Cellular toxicity of TiO2-based nanofilaments.
abstract: At present, nanofilaments are not exclusively based on carbon atoms but can be produced from many inorganic materials in the form of nanotubes and nanowires. It is essential to systematically assess the acute toxicity of these newly synthesized materials since it cannot be predicted from the known toxicity of the same material in another form. Here, the cellular toxicity of TiO2-based nanofilaments was studied in relation to their morphology and surface chemistry. These structures produced by hydrothermal treatment were titanate nanotubes and nanowires with a Na(x)TiO(2+delta) composition. The cytotoxic effect was mainly evaluated by MTT assays combined with direct cell counting and cytopathological analyses of the lung tumor cells. Our work clearly demonstrated that the presence of Na(x)TiO(2+delta) nanofilaments had a strong dose-dependent effect on cell proliferation and cell death. Nanofilament internalization and alterations in cell morphology were observed. Acid treatment performed to substitute Na(+) with H(+) in the Na(x)TiO(2+delta) nanofilaments strongly enhanced the cytotoxic action. This effect was attributed to structural imperfections, which are left by the atom diffusion during the substitution. On the basis of our findings, we conclude that TiO2-based nanofilaments are cytotoxic and thus precautions should be taken during their manipulation.
authors.affiliation: Institute of Physics of Condensed Matter (IPMC), Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland. arnaud.magrez@epfl.ch
authors.forename: Arnaud
authors.initials: A
authors.lastname: Magrez
authors.forename: Lenke
authors.initials: L
authors.lastname: Horváth
authors.forename: Rita
authors.initials: R
authors.lastname: Smajda
authors.forename: Valérie
authors.initials: V
authors.lastname: Salicio
authors.forename: Nathalie
authors.initials: N
authors.lastname: Pasquier
authors.forename: László
authors.initials: L
authors.lastname: Forró
authors.forename: Beat
authors.initials: B
authors.lastname: Schwaller
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D048430:Cell Shape / Q000187:drug effects; D006801:Humans; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D014025:Titanium / Q000737:chemistry / Q000633:toxicity*
chemical_list: C009495:titanium dioxide; D014025:Titanium