title: Evaluation of titanium dioxide nanocrystal-induced genotoxicity by the cytokinesis-block micronucleus assay and the Drosophila wing spot test.
abstract: Titanium dioxide nanocrystals (TiO2 NCs) crystalline structures include anatase, rutile and brookite. This study evaluated the genotoxic effects of 3.4 and 6.2 nm anatase TiO2 NCs and 78.0 nm predominantly rutile TiO2 NCs through an in vitro micronucleus (MN) assay using V79 cells and an in vivo somatic mutation and recombination test in Drosophila wings. The MN assay was performed with nontoxic concentrations of TiO2 NCs. Only anatase (3.4 nm) at the highest concentration (120 μM) induced genotoxicity in V79 cells. In the in vivo test, Drosophila melanogaster larvae obtained from standard (ST) or high bioactivation (HB) crosses were treated with TiO2 NCs. In the ST cross, no mutagenic effects were observed. However, in the HB cross, TiO2 NCs (3.4 nm) were mutagenic at 1.5625 and 3.125 mM, while 78.0 nm NCs increased mutant spots at all concentrations tested except 3.125 mM. Only the smallest anatase TiO2 NCs induced mutagenic effects in vitro and in vivo. For rutile TiO2 NCs, no clastogenic/aneugenic effects were observed in the MN assay. However, they were mutagenic in Drosophila. Therefore, both anatase and rutile TiO2 NCs induced mutagenicity. Further research is necessary to clarify the TiO2 NCs genotoxic/mutagenic action mechanisms.
authors: Laboratório de Mutagênese, Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, 38400-902, Brazil.
authors: Érica de Melo
authors: Éde M
authors: Reis
authors: Laboratório de Mutagênese, Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, 38400-902, Brazil.
authors: Alexandre Azenha Alves de
authors: AA
authors: Rezende
authors: Universidade de Franca, Franca, SP, 14404-600, Brazil.
authors: Pollyanna Francielli de
authors: PF
authors: Oliveira
authors: Universidade de Franca, Franca, SP, 14404-600, Brazil.
authors: Heloiza Diniz
authors: HD
authors: Nicolella
authors: Universidade de Franca, Franca, SP, 14404-600, Brazil.
authors: Denise Crispim
authors: DC
authors: Tavares
authors: Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, 38400-902, Brazil.
authors: Anielle Christine Almeida
authors: AC
authors: Silva
authors: Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, 38400-902, Brazil.
authors: Noelio Oliveira
authors: NO
authors: Dantas
authors: Laboratório de Mutagênese, Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, 38400-902, Brazil. Electronic address: maspano@ufu.br.
authors: Mário Antônio
authors: MA
authors: Spanó
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003412:Cricetulus; D048749:Cytokinesis; D004249:DNA Damage / Q000187:drug effects*; D004331:Drosophila melanogaster / Q000166:cytology / Q000187:drug effects* / Q000235:genetics; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D007814:Larva / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D008168:Lung / Q000166:cytology / Q000187:drug effects; D008297:Male; D053768:Metal Nanoparticles / Q000633:toxicity*; D015162:Micronucleus Tests / Q000379:methods*; D009152:Mutagenicity Tests; D014025:Titanium / Q000633:toxicity*; D014921:Wings, Animal / Q000187:drug effects*
chemical_list: C009495:titanium dioxide; D014025:Titanium
keywords: In vitro; In vivo; Mutagenicity; Nanotoxicology; Titania; Titanium (IV) oxide