title: In vivo genotoxicity assessment of titanium dioxide nanoparticles by Allium cepa root tip assay at high exposure concentrations.
abstract: The industrial production and commercial applications of titanium dioxide nanoparticles have increased considerably in recent times, which has increased the probability of environmental contamination with these agents and their adverse effects on living systems. This study was designed to assess the genotoxicity potential of TiO2 NPs at high exposure concentrations, its bio-uptake, and the oxidative stress it generated, a recognised cause of genotoxicity. Allium cepa root tips were treated with TiO2 NP dispersions at four different concentrations (12.5, 25, 50, 100 µg/mL). A dose dependant decrease in the mitotic index (69 to 21) and an increase in the number of distinctive chromosomal aberrations were observed. Optical, fluorescence and confocal laser scanning microscopy revealed chromosomal aberrations, including chromosomal breaks and sticky, multipolar, and laggard chromosomes, and micronucleus formation. The chromosomal aberrations and DNA damage were also validated by the comet assay. The bio-uptake of TiO2 in particulate form was the key cause of reactive oxygen species generation, which in turn was probably the cause of the DNA aberrations and genotoxicity observed in this study.
authors: Centre for Nanobiotechnology, VIT University, Vellore, Tamilnadu, India.
authors: Sunandan
authors: S
authors: Pakrashi
authors: Centre for Nanobiotechnology, VIT University, Vellore, Tamilnadu, India.
authors: Nitin
authors: N
authors: Jain
authors: Centre for Nanobiotechnology, VIT University, Vellore, Tamilnadu, India.
authors: Swayamprava
authors: S
authors: Dalai
authors: Centre for Nanobiotechnology, VIT University, Vellore, Tamilnadu, India.
authors: Jerobin
authors: J
authors: Jayakumar
authors: Department of Materials Engineering, Indian Institute of Science, Bangalore, Karnataka, India.
authors: Prathna Thanjavur
authors: PT
authors: Chandrasekaran
authors: Department of Materials Engineering, Indian Institute of Science, Bangalore, Karnataka, India ; Department of Chemical Technology, University of Johannesburg, Johannesburg, Gauteng, South Africa.
authors: Ashok M
authors: AM
authors: Raichur
authors: Centre for Nanobiotechnology, VIT University, Vellore, Tamilnadu, India.
authors: Natarajan
authors: N
authors: Chandrasekaran
authors: Centre for Nanobiotechnology, VIT University, Vellore, Tamilnadu, India.
authors: Amitava
authors: A
authors: Mukherjee
mesh_terms: D002869:Chromosome Aberrations / Q000139:chemically induced; D020552:Comet Assay; D004249:DNA Damage; D053768:Metal Nanoparticles / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced; D018613:Microscopy, Confocal; D019697:Onions / Q000166:cytology*; D018384:Oxidative Stress; D018517:Plant Roots / Q000166:cytology*; D014025:Titanium / Q000737:chemistry / Q000633:toxicity*; D014116:Toxicology / Q000379:methods*
chemical_list: C009495:titanium dioxide; D014025:Titanium