Singlet oxygen plays a key role in the toxicity and DNA damage caused by nanometric TiO sub(2) in human keratinocytes

• Published in: Nanoscale Vol. 5; no. 14; pp. 6567 - 6576
• Main Authors: Fenoglio, Ivana, Ponti, Jessica, Alloa, Elisa, Ghiazza, Mara, Corazzari, Ingrid, Capomaccio, Robin, Rembges, Diana, Oliaro-Bosso, Simonetta, Rossi, Francois
• Format: Journal Article
• Language: English
• Published: 01.06.2013
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c3nr01191g

Nanometric TiO sub(2) has been reported to be cytotoxic and genotoxic in different in vitromodels when activated by UV light. However, a clear picture of the species mediating the observed toxic effects is still missing. Here, a nanometric TiO sub(2) 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 mu g mL super(-1), 15 min UVA/B exposure at 216-36 mJ m super(-2) respectively). The data reported herein indicate that the photo-toxicity of TiO sub(2) 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.