title: Singlet oxygen plays a key role in the toxicity and DNA damage caused by nanometric TiO2 in human keratinocytes.
abstract: Nanometric TiO2 has been reported to be cytotoxic and genotoxic in different in vitro models when activated by UV light. However, a clear picture of the species mediating the observed toxic effects is still missing. Here, a nanometric TiO2 powder has been modified at the surface to completely inhibit its photo-catalytic activity and to inhibit the generation of all reactive species except for singlet oxygen. The prepared powders have been tested for their ability to induce strand breaks in plasmid DNA and for their cytotoxicity and genotoxicity toward human keratinocyte (HaCaT) cells (100-500 μg mL(-1), 15 min UVA/B exposure at 216-36 mJ m(-2) respectively). The data reported herein indicate that the photo-toxicity of TiO2 is mainly triggered by particle-derived singlet oxygen. The data presented herein contribute to the knowledge of structure-activity relationships which are needed for the design of safe nanomaterials.
authors.affiliation: Dipartimento di Chimica, G. Scansetti Interdepartmental Center for Studies on Asbestos and other Toxic Particulates, University of Torino, via P. Giuria 7, 10125-Torino, Italy. ivana.fenoglio@unito.it
authors.forename: Ivana
authors.initials: I
authors.lastname: Fenoglio
authors.forename: Jessica
authors.initials: J
authors.lastname: Ponti
authors.forename: Elisa
authors.initials: E
authors.lastname: Alloa
authors.forename: Mara
authors.initials: M
authors.lastname: Ghiazza
authors.forename: Ingrid
authors.initials: I
authors.lastname: Corazzari
authors.forename: Robin
authors.initials: R
authors.lastname: Capomaccio
authors.forename: Diana
authors.initials: D
authors.lastname: Rembges
authors.forename: Simonetta
authors.initials: S
authors.lastname: Oliaro-Bosso
authors.forename: François
authors.initials: F
authors.lastname: Rossi
mesh_terms: D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects* / Q000528:radiation effects; D006801:Humans; D015603:Keratinocytes / Q000166:cytology; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D026082:Singlet Oxygen / Q000378:metabolism*; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: C009495:titanium dioxide; D026082:Singlet Oxygen; D014025:Titanium