@article{He2014185,
title = {An in vivo study on the photo-enhanced toxicities of S-doped TiO 2 nanoparticles to zebrafish embryos (Danio rerio) in terms of malformation, mortality, rheotaxis dysfunction, and DNA damage},
author = { X.a He and W.G.a b Aker and H.-M.a Hwang},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84905976063&partnerID=40&md5=6c85db88907922f3bf36e6084494d264},
doi = {10.3109/17435390.2013.874050},
issn = {17435390},
year = {2014},
date = {2014-01-01},
journal = {Nanotoxicology},
volume = {8},
number = {SUPPL. 1},
pages = {185-195},
publisher = {Informa Healthcare},
abstract = {The role of light on the acute toxicities of S-doped and Sigma TiO 2 nanoparticles in zebrafish was studied. Metrics included mortality for both, and rheotaxis dysfunction and DNA damage for S-doped only. It was found that the acute toxicity of S-TiO2 nanoparticles was enhanced by simulated sunlight (SSL) irradiation (96-h LC50 of 116.56 ppm) and exceeded that of Sigma TiO2, which was essentially non-toxic. Behavioral disorder, in terms of rheotaxis, was significantly increased by treatment with S-TiO2 nanoparticles under SSL irradiation. In order to further understand its toxicity mechanism, we investigated hair cells in neuromasts of the posterior lateral line (PLL) using DASPEI staining. Significant hair cell damage was observed in the treated larvae. The Comet assay was employed to investigate the DNA damage, which might be responsible for the loss of hair cells. Production of the superoxide anion (O ·- 2), a major ROS generated by TiO2 nanoparticles, was assayed and used to postulate causative factors to account for these damages. Oxidative effects were most severe in the liver, heart, intestine, pancreatic duct, and pancreatic islet-results consistent with our earlier findings in the investigation of embryonic malformation. TEM micrographs, used to further investigate the fate of S-TiO2 nanoparticles at the cellular level, suggested receptor-mediated autophagy and vacuolization. Our findings validate the benefit of using the transparent zebrafish embryo as an in vivo model for evaluating photo-induced nanotoxicity. These results highlight the importance of conducting a systematic risk assessment in connection with the use of doped TiO2 nanoparticles in aquatic ecosystems. © 2014 Informa UK Ltd. All rights reserved.},
note = {cited By 3},
keywords = {Animals; DNA Damage; Embryo, Electron, nanoparticle; reactive oxygen metabolite; superoxide; titanium dioxide; titanium oxide nanoparticle; unclassified drug; metal nanoparticle; titanium; titanium dioxide, Nonmammalian; Metal Nanoparticles; Microscopy, Transmission; Spectrophotometry, Ultraviolet; Titanium; Zebrafish},
pubstate = {published},
tppubtype = {article}
}

@article{He2014185b,
title = {An in vivo study on the photo-enhanced toxicities of S-doped TiO 2 nanoparticles to zebrafish embryos (Danio rerio) in terms of malformation, mortality, rheotaxis dysfunction, and DNA damage},
author = { Aker W G Hwang H.-M. He X.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84905976063&partnerID=40&md5=6c85db88907922f3bf36e6084494d264},
doi = {10.3109/17435390.2013.874050},
year = {2014},
date = {2014-01-01},
journal = {Nanotoxicology},
volume = {8},
number = {SUPPL. 1},
pages = {185--195},
abstract = {The role of light on the acute toxicities of S-doped and Sigma TiO 2 nanoparticles in zebrafish was studied. Metrics included mortality for both, and rheotaxis dysfunction and DNA damage for S-doped only. It was found that the acute toxicity of S-TiO2 nanoparticles was enhanced by simulated sunlight (SSL) irradiation (96-h LC50 of 116.56 ppm) and exceeded that of Sigma TiO2, which was essentially non-toxic. Behavioral disorder, in terms of rheotaxis, was significantly increased by treatment with S-TiO2 nanoparticles under SSL irradiation. In order to further understand its toxicity mechanism, we investigated hair cells in neuromasts of the posterior lateral line (PLL) using DASPEI staining. Significant hair cell damage was observed in the treated larvae. The Comet assay was employed to investigate the DNA damage, which might be responsible for the loss of hair cells. Production of the superoxide anion (O textperiodcentered- 2), a major ROS generated by TiO2 nanoparticles, was assayed and used to postulate causative factors to account for these damages. Oxidative effects were most severe in the liver, heart, intestine, pancreatic duct, and pancreatic islet-results consistent with our earlier findings in the investigation of embryonic malformation. TEM micrographs, used to further investigate the fate of S-TiO2 nanoparticles at the cellular level, suggested receptor-mediated autophagy and vacuolization. Our findings validate the benefit of using the transparent zebrafish embryo as an in vivo model for evaluating photo-induced nanotoxicity. These results highlight the importance of conducting a systematic risk assessment in connection with the use of doped TiO2 nanoparticles in aquatic ecosystems. textcopyright 2014 Informa UK Ltd. All rights reserved.},
keywords = {Animals; DNA Damage; Embryo, Electron, nanoparticle; reactive oxygen metabolite; superoxide; titanium dioxide; titanium oxide nanoparticle; unclassified drug; metal nanoparticle; titanium; titanium dioxide, Nonmammalian; Metal Nanoparticles; Microscopy, Transmission; Spectrophotometry, Ultraviolet; Titanium; Zebrafish},
pubstate = {published},
tppubtype = {article}
}

@article{Pathakoti20139988,
title = {Photoinactivation of Escherichia coli by sulfur-doped and nitrogen-fluorine-codoped TiO2 nanoparticles under solar simulated light and visible light irradiation},
author = { Morrow S Han C Pelaez M He X Dionysiou D D Hwang H.-M. Pathakoti K.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883515650&partnerID=40&md5=e99376f9e227f31be565eedccf960cf7},
doi = {10.1021/es401010g},
year = {2013},
date = {2013-01-01},
journal = {Environmental Science and Technology},
volume = {47},
number = {17},
pages = {9988--9996},
abstract = {Titanium dioxide (TiO2) is one of the most widely used photocatalysts for the degradation of organic contaminants in water and air. Visible light (VL) activated sulfur-doped TiO2 (S-TiO2) and nitrogen-fluorine-codoped TiO2 (N-F-TiO2) were synthesized by sol-gel methods and characterized. Their photoinactivation performance was tested against Escherichia coli under solar simulated light (SSL) and VL irradiation with comparison to commercially available TiO 2. Undoped Degussa-Evonik P-25 (P-25) and Sigma-TiO2 showed the highest photocatalytic activity toward E coli inactivation under SSL irradiation, while S-TiO2 showed a moderate toxicity. After VL irradiation, Sigma-TiO2 showed higher photoinactivation, whereas S-TiO2 and P-25 showed moderate toxicity. Oxidative stress to E coli occurred via formation of hydroxyl radicals leading to lipid peroxidation as the primary mechanism of bacterial inactivation. Various other biological models, including human keratinocytes (HaCaT), zebrafish liver cells (ZFL), and zebrafish embryos were also used to study the toxicity of TiO2 NPs. In conclusion, N-F-TiO2 did not show any toxicity based on the assay results from all the biological models used in this study, whereas S-TiO 2 was toxic to zebrafish embryos under all the test conditions. These findings also demonstrate that the tested TiO2 nanoparticles do not show any adverse effects in HaCaT and ZFL cells. textcopyright 2013 American Chemical Society.},
keywords = {Animals; Embryo, Bacterial inactivation; Degradation of organic contaminants; Human keratinocytes; Hydroxyl radicals; Lipid peroxidation; Photocatalytic activities; Solar-simulated light; Visible-light irradiation, barium ion; cadmium; chromium; fluorine; hydroxyl radical; iron; manganese; nanoparticle; nitrogen; reactive oxygen metabolite; sulfur; titanium dioxide; zinc, bioassay; catalyst; coliform bacterium; cyprinid; embryo; light effect; organic pollutant; oxidation; oxide; particulate matter; radiation balance; toxicity; visible spectrum, Doping (additives); Escherichia coli; Fluorine; Irradiation; Light; Nanoparticles; Nitrogen; Photocatalysts; Sol-gel process; Sulfur; Toxicity, Electron, Nonmammalian; Escherichia coli; Fluorine; Keratinocytes; Light; Liver; Microscopy, Titanium dioxide, Transmission; Nanoparticles; Nitrogen; Photoelectron Spectroscopy; Photolysis; Reactive Oxygen Species; Sulfur; Sunlight; Titanium; X-Ray Diffraction; Zebrafish},
pubstate = {published},
tppubtype = {article}
}

@article{Dasari20131925,
title = {Effect of humic acids and sunlight on the cytotoxicity of engineered zinc oxide and titanium dioxide nanoparticles to a river bacterial assemblage},
author = { Hwang H.-M. Dasari T.P.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883767125&partnerID=40&md5=e2770cffb5521b7bf048284305c93c0a},
doi = {10.1016/S1001-0742(12)60271-X},
year = {2013},
date = {2013-01-01},
journal = {Journal of Environmental Sciences (China)},
volume = {25},
number = {9},
pages = {1925--1935},
abstract = {The effect of a terrestrial humic acid (HA) and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles (ZnONPs) and titanium dioxide nanoparticles (TiO2NPs) to natural aquatic bacterial assemblages was measured with spread plate counting. The effect of HA (10 and 40 ppm) on the cytotoxicity of ZnONPs and TiO2NPs was tested factorially in the presence and absence of natural sunlight (light irradiation (LI)). The experiment was of full factorial, completely randomized design and the results were analyzed using the General Linear Model in SAS analytical software. The method of least squares means was used to separate the means or combinations of means. We determined the mechanism of toxicity via measurements of oxidative stress and metal ions. The toxicity of ZnONPs and TiO2NPs to natural aquatic bacterial assemblages appears to be concentration dependent. Moreover, the cytotoxicity of ZnONPs and TiO2NPs appeared to be affected by HA concentration, the presence of sunlight irradiation, and the dynamic multiple interactions among these factors. With respect to light versus darkness in the control group, the data indicate that bacterial viability was inhibited more in the light exposure than in the darkness exposure. The same was true in the HA treatment groups. With respect to terrestrial versus Suwanee River HA for a given nanoparticle, in light versus darkness, bacterial viability was more inhibited in the light treatment groups containing the terrestrial HA than in those containing Suwanee River HA. Differences in the extent of reactive oxygen species formation, adsorption/binding of ZnONPs/TiO2NPs by HA, and the levels of free metal ions were speculated to account for the observed cytotoxicity. TEM images indicate the attachment and binding of the tested nanoparticles to natural bacterial assemblages. Besides the individual parameter, significant effects on bacterial viability count were also observed in the following combined treatments: HA-ZnONPs, HA-LI, ZnONPs-LI, and HA-ZnONPs-LI. The main effects of all independent variables, plus interaction effects in all cases were significant with TiO2NPs. textcopyright 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.},
keywords = {article; bacterium; chemistry; classification; humic substance; microbiology; oxidative stress; river; sunlight; transmission electron microscopy, Bacteria, Bacteria; Humic Substances; Metal Nanoparticles; Microscopy, Bacterial assemblages; Completely randomized designs; Humic acid; Median Lethal concentration; Method of least squares; Reactive oxygen species; Titanium dioxide nanoparticles; Zinc oxide nanoparticles, bacterium; concentration (composition); experimental study; humic acid; nanotechnology; oxidation; titanium; toxicity; zinc, Biological materials; Cytotoxicity; Enzyme immobilization; Irradiation; Least squares approximations; Metal ions; Nanoparticles; Organic acids; Oxides; Oxygen; Rivers; Titanium dioxide; Toxicity; Zinc oxide, Electron, metal nanoparticle; titanium; titanium dioxide, Suwannee River; United States, Transmission; Oxidative Stress; Rivers; Sunlight; Titanium; Water Microbiology},
pubstate = {published},
tppubtype = {article}
}