The Experts below are selected from a list of 30204 Experts worldwide ranked by ideXlab platform

Fuqiang Huang - One of the best experts on this subject based on the ideXlab platform.

Xiaobo Chen - One of the best experts on this subject based on the ideXlab platform.

John W. Eaton - One of the best experts on this subject based on the ideXlab platform.

  • Titanium Dioxide (Tio2) Nanoparticles Preferentially Induce Cell Death in Transformed Cells in a Bak/Bax-Independent Fashion
    PloS one, 2012
    Co-Authors: Yanglong Zhu, John W. Eaton
    Abstract:

    While the cytotoxic effects of Titanium Dioxide (Tio2) nanoparticles have been under intense investigation, the molecular mechanisms of this cytotoxicity remain unknown. Here we investigated the influence of oncogenic transformation and a major apoptotic signaling pathway on cellular responses to Tio2 nanoparticles. Isogenic wild-type (WT) and apoptosis-resistant (Bak−/−Bax−/−) cell lines with and without tumorigenic transformation were examined. Tio2 nanoparticles preferentially reduced viability of tumorigenic cells in a dose-dependent fashion compared with their untransformed counterparts. Importantly, the elevated cytotoxicity of Tio2 nanoparticles was independent of a major Bak/Bax-dependent apoptosis pathway. Because transformation does not affect cellular fluid-phase endocytosis or nanoparticle uptake, it is likely that the increased cytotoxicity in tumor cells is due to the interaction between Tio2 nanoparticles and the lysosomal compartment. Overall, our data indicate that Tio2 nanoparticles induce cytotoxicity preferentially in transformed cells independent of a major apoptotic signaling pathway.

  • Titanium Dioxide Tio2 nanoparticles preferentially induce cell death in transformed cells in a bak bax independent fashion
    PLOS ONE, 2012
    Co-Authors: Yanglong Zhu, John W. Eaton
    Abstract:

    While the cytotoxic effects of Titanium Dioxide (Tio2) nanoparticles have been under intense investigation, the molecular mechanisms of this cytotoxicity remain unknown. Here we investigated the influence of oncogenic transformation and a major apoptotic signaling pathway on cellular responses to Tio2 nanoparticles. Isogenic wild-type (WT) and apoptosis-resistant (Bak−/−Bax−/−) cell lines with and without tumorigenic transformation were examined. Tio2 nanoparticles preferentially reduced viability of tumorigenic cells in a dose-dependent fashion compared with their untransformed counterparts. Importantly, the elevated cytotoxicity of Tio2 nanoparticles was independent of a major Bak/Bax-dependent apoptosis pathway. Because transformation does not affect cellular fluid-phase endocytosis or nanoparticle uptake, it is likely that the increased cytotoxicity in tumor cells is due to the interaction between Tio2 nanoparticles and the lysosomal compartment. Overall, our data indicate that Tio2 nanoparticles induce cytotoxicity preferentially in transformed cells independent of a major apoptotic signaling pathway.

Anita Mukherjee - One of the best experts on this subject based on the ideXlab platform.

  • Cytotoxic, genotoxic and the hemolytic effect of Titanium Dioxide (Tio2) nanoparticles on human erythrocyte and lymphocyte cells in vitro
    Journal of applied toxicology : JAT, 2013
    Co-Authors: Manosij Ghosh, Anirban Chakraborty, Anita Mukherjee
    Abstract:

    With the increasing clinical use of Titanium Dioxide (Tio2 ) nanoparticles, a better understanding of their safety in the blood stream is required. The present study evaluates the toxic effect of commercially available Tio2 nanoparticles (~100 nm) using a battery of cytotoxic, genotoxic, hemolytic and morphological parameters. The cytotoxic effects of Tio2 nanoparticles in human lymphocyte cells were studied with respect to membrane damage, mitochondrial function, metabolic activity and lysosomal membrane stability. Genotoxicity in lymphocyte cells was quantitated using a comet assay. The mode of cell death (apoptosis/necrosis) was evaluated using PI/Annexin V staining. Tio2 nanoparticles were also evaluated for their hemolytic properties, osmotic fragility and interaction with hemoglobin. Human erythrocyte cells were studied for morphological alterations using atomic force microscopy (AFM). Results suggest that the particles could induce a significant reduction in mitochondrial dehydrogenase activity in human lymphocyte cells. Membrane integrity remained unaffected by nanoparticle treatment. DNA damage and apoptosis were induced by Tio2 nanoparticles in a dose-dependent manner. A study on human erythrocyte cells revealed a hemolytic property of Tio2 nanoparticles characterized by spherocytosis and echinocytosis. Spectral analysis revealed a hemoglobin Tio2 nanoparticle interaction. Our in vitro study results suggest that commercially available blood contacting nanoparticles (Tio2 nanoparticle) should be carefully evaluated for their toxic potential.

  • genotoxicity of Titanium Dioxide Tio2 nanoparticles at two trophic levels plant and human lymphocytes
    Chemosphere, 2010
    Co-Authors: Manosij Ghosh, Maumita Bandyopadhyay, Anita Mukherjee
    Abstract:

    The environmental fate and behaviour of Titanium Dioxide (Tio2) nanoparticles is a rapidly expanding area of research. There is a paucity of information regarding toxic effect of Tio2 nanoparticles in plants and to certain extent in humans. The present study focuses on the effect of exposure of Tio2 nanoparticles in two trophic levels, plant and human lymphocytes. The genotoxicity of Tio2 nanoparticles was evaluated using classical genotoxic endpoints, comet assay and DNA laddering technique. DNA damaging potential of Tio2 nanoparticles in Allium cepa and Nicotiana tabacum as representative of plant system could be confirmed in the comet assay and DNA laddering experiments. In Allium micronuclei and chromosomal aberrations correlated with the reduction in root growth. We detected increased level of malondialdehyde (MDA) concentration at 4 mM (0.9 lM) treatment dose of Tio2 nanoparticles in Allium cepa. This indicated that lipid peroxidation could be involved as one of the mechanism leading to DNA damage. A comparative study of the cytotoxic and genotoxic potential of Tio2 nanoparticles and bulk Tio2 particles in human lymphocytes also reveal interesting results. While Tio2 nanoparticles were found to be genotoxic at a low dose of 0.25 mM followed by a decrease in extent of DNA damage at higher concentrations; bulk Tio2 particles reveal a more or less dose dependent effect, genotoxic only at dose 1.25 mM and above. The study thus confirms the genotoxic potential of Tio2 nanoparticles in both plant and human lymphocytes.

Kuan-chung Chen - One of the best experts on this subject based on the ideXlab platform.

  • A Review on the Pathways of the Improved Structural Characteristics and Photocatalytic Performance of Titanium Dioxide (Tio2) Thin Films Fabricated by the Magnetron-Sputtering Technique
    Catalysts, 2020
    Co-Authors: Yu-hsiang Wang, Kazi Hasibur Rahman, Kuan-chung Chen
    Abstract:

    Titanium Dioxide (Tio2) thin films are used for a broad range of applications such as wastewater treatment, photocatalytic degradation activity, water splitting, antibacterial and also in biomedical applications. There is a wide range of synthesis techniques for the deposition of Tio2 thin films, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), both of which are well known deposition methods. Layer by layer deposition with good homogeneity, even thickness and good adhesive nature is possible by using the PVD technique, with the products being used for photocatalytic applications. This review studies the effects of magnetron sputtering conditions on Tio2 films. This innovative technique can enhance the photocatalytic activity by increasing the thickness of the film higher than any other methods. The main purpose of this article is to review the effects of DC and RF magnetron sputtering conditions on the preparation of Tio2 thin films for photocatalysis. The characteristics of Tio2 films (i.e., structure, composition, and crystallinity) are affected significantly by the substrate type, the sputtering power, the distance between substrate and target, working pressure, argon/oxygen ratio, deposition time, substrate temperature, dopant types, and finally the annealing treatment. The photocatalytic activity and optical properties, including the degree of crystallinity, band gap (Eg), refractive index (n), transmittance (T), and extinction coefficient (k), of Tio2 films are dependent on the above- mentioned film characteristics. Optimal Tio2 films should have a small particle size, a strong degree of crystallinity, a low band gap, a low contact angle, a high refractive index, transmittance, and extinction coefficient. Finally, metallic and nonmetallic dopants can be added to enhance the photocatalytic activity of Tio2 films by narrowing the band gap.