title: Role of Zn doping in oxidative stress mediated cytotoxicity of TiO2 nanoparticles in human breast cancer MCF-7 cells.
abstract: We investigated the effect of Zn-doping on structural and optical properties as well as cellular response of TiO2 nanoparticles (NPs) in human breast cancer MCF-7 cells. A library of Zn-doped (1-10 at wt%) TiO2 NPs was prepared. Characterization data indicated that dopant Zn was incorporated into the lattice of host TiO2. The average particle size of TiO2 NPs was decreases (38 to 28 nm) while the band gap energy was increases (3.35 eV-3.85 eV) with increasing the amount of Zn-doping. Cellular data demonstrated that Zn-doped TiO2 NPs induced cytotoxicity (cell viability reduction, membrane damage and cell cycle arrest) and oxidative stress (reactive oxygen species generation &glutathione depletion) in MCF-7 cells and toxic intensity was increases with increasing the concentration of Zn-doping. Molecular data revealed that Zn-doped TiO2 NPs induced the down-regulation of super oxide dismutase gene while the up-regulation of heme oxygenase-1 gene in MCF-7 cells. Cytotoxicity induced by Zn-doped TiO2 NPs was efficiently prevented by N-acetyl-cysteine suggesting that oxidative stress might be the primarily cause of toxicity. In conclusion, our data indicated that Zn-doping decreases the particle size and increases the band gap energy as well the oxidative stress-mediated toxicity of TiO2 NPs in MCF-7 cells.
authors.affiliation: King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Maqusood
authors.initials: M
authors.lastname: Ahamed
authors.affiliation: King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, Saudi Arabia.
authors.forename: M A Majeed
authors.initials: MA
authors.lastname: Khan
authors.affiliation: King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mohd Javed
authors.initials: MJ
authors.lastname: Akhtar
authors.affiliation: King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, Saudi Arabia.|Department of Physics and Astronomy, College of Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Hisham A
authors.initials: HA
authors.lastname: Alhadlaq
authors.affiliation: King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, Saudi Arabia.|Nanomedicine Research Unit, Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Aws
authors.initials: A
authors.lastname: Alshamsan
mesh_terms: D000072283:A549 Cells; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D005978:Glutathione / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D061986:MCF-7 Cells; D053758:Nanoparticles / Q000008:administration & dosage*; D018384:Oxidative Stress / Q000187:drug effects*; D010316:Particle Size; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects; D015032:Zinc / Q000494:pharmacology*
chemical_list: D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium; D005978:Glutathione; D015032:Zinc