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  1. Mucin secretion induced by titanium dioxide nanoparticles.

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    Eric Y T Chen

    2011-01-01

    Full Text Available Nanoparticle (NP exposure has been closely associated with the exacerbation and pathophysiology of many respiratory diseases such as Chronic Obstructive Pulmonary Disease (COPD and asthma. Mucus hypersecretion and accumulation in the airway are major clinical manifestations commonly found in these diseases. Among a broad spectrum of NPs, titanium dioxide (TiO(2, one of the PM10 components, is widely utilized in the nanoindustry for manufacturing and processing of various commercial products. Although TiO(2 NPs have been shown to induce cellular nanotoxicity and emphysema-like symptoms, whether TiO(2 NPs can directly induce mucus secretion from airway cells is currently unknown. Herein, we showed that TiO(2 NPs (<75 nm can directly stimulate mucin secretion from human bronchial ChaGo-K1 epithelial cells via a Ca(2+ signaling mediated pathway. The amount of mucin secreted was quantified with enzyme-linked lectin assay (ELLA. The corresponding changes in cytosolic Ca(2+ concentration were monitored with Rhod-2, a fluorescent Ca(2+ dye. We found that TiO(2 NP-evoked mucin secretion was a function of increasing intracellular Ca(2+ concentration resulting from an extracellular Ca(2+ influx via membrane Ca(2+ channels and cytosolic ER Ca(2+ release. The calcium-induced calcium release (CICR mechanism played a major role in further amplifying the intracellular Ca(2+ signal and in sustaining a cytosolic Ca(2+ increase. This study provides a potential mechanistic link between airborne NPs and the pathoetiology of pulmonary diseases involving mucus hypersecretion.

  2. Cerium dioxide nanoparticles do not modulate the lipopolysaccharide-induced inflammatory response in human monocytes

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    Hussain S

    2012-03-01

    Full Text Available Salik Hussain1,*, Faris Al-Nsour1,*, Annette B Rice1, Jamie Marshburn1, Zhaoxia Ji2, Jeffery I Zink2, Brenda Yingling1, Nigel J Walker3, Stavros Garantziotis11Clinical Research Unit, National Institute of Environmental Health Sciences/National Institute of Health, Research Triangle Park, NC, 2UC Center for Environmental Implications of Nanotechnology University of California, Los Angeles, CA, 3Division of National Toxicology Program, National Institute of Environmental Health Sciences/National Institute of Health, Research Triangle Park, NC, USA*Both are principal authorsBackground: Cerium dioxide (CeO2 nanoparticles have potential therapeutic applications and are widely used for industrial purposes. However, the effects of these nanoparticles on primary human cells are largely unknown. The ability of nanoparticles to exacerbate pre-existing inflammatory disorders is not well documented for engineered nanoparticles, and is certainly lacking for CeO2 nanoparticles. We investigated the inflammation-modulating effects of CeO2 nanoparticles at noncytotoxic concentrations in human peripheral blood monocytes.Methods: CD14+ cells were isolated from peripheral blood samples of human volunteers. Cells were exposed to either 0.5 or 1 µg/mL of CeO2 nanoparticles over a period of 24 or 48 hours with or without lipopolysaccharide (10 ng/mL prestimulation. Modulation of the inflammatory response was studied by measuring secreted tumor necrosis factor-alpha, interleukin-1beta, macrophage chemotactic protein-1, interferon-gamma, and interferon gamma-induced protein 10.Results: CeO2 nanoparticle suspensions were thoroughly characterized using dynamic light scattering analysis (194 nm hydrodynamic diameter, zeta potential analysis (-14 mV, and transmission electron microscopy (irregular-shaped particles. Transmission electron microscopy of CD14+ cells exposed to CeO2 nanoparticles revealed that these nanoparticles were efficiently internalized by monocytes and

  3. Titanium dioxide nanoparticles exacerbate DSS-induced colitis: role of the NLRP3 inflammasome

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    Ruiz, Pedro A; Morón, Belen; Becker, Helen M; Lang, Silvia; Atrott, Kirstin; Spalinger, Marianne R; Scharl, Michael; Wojtal, Kacper A; Fischbeck-Terhalle, Anne; Frey-Wagner, Isabelle; Hausmann, Martin; Kraemer, Thomas; Rogler, Gerhard

    2017-01-01

    Objective Western lifestyle and diet are major environmental factors playing a role in the development of IBD. Titanium dioxide (TiO2) nanoparticles are widely used as food additives or in pharmaceutical formulations and are consumed by millions of people on a daily basis. We investigated the effects of TiO2 in the development of colitis and the role of the nucleotide-binding oligomerisation domain receptor, pyrin domain containing (NLRP)3 inflammasome. Design Wild-type and NLRP3-deficient mice with dextran sodium sulfate-induced colitis were orally administered with TiO2 nanoparticles. The proinflammatory effects of TiO2 particles in cultured human intestinal epithelial cells (IECs) and macrophages were also studied, as well as the ability of TiO2 crystals to traverse IEC monolayers and accumulate in the blood of patients with IBD using inductively coupled plasma mass spectrometry. Results Oral administration of TiO2 nanoparticles worsened acute colitis through a mechanism involving the NLRP3 inflammasome. Importantly, crystals were found to accumulate in spleen of TiO2-administered mice. In vitro, TiO2 particles were taken up by IECs and macrophages and triggered NLRP3-ASC-caspase-1 assembly, caspase-1 cleavage and the release of NLRP3-associated interleukin (IL)-1β and IL-18. TiO2 also induced reactive oxygen species generation and increased epithelial permeability in IEC monolayers. Increased levels of titanium were found in blood of patients with UC having active disease. Conclusion These findings indicate that individuals with a defective intestinal barrier function and pre-existing inflammatory condition, such as IBD, might be negatively impacted by the use of TiO2 nanoparticles. PMID:26848183

  4. Titanium dioxide nanoparticles exacerbate DSS-induced colitis: role of the NLRP3 inflammasome.

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    Ruiz, Pedro A; Morón, Belen; Becker, Helen M; Lang, Silvia; Atrott, Kirstin; Spalinger, Marianne R; Scharl, Michael; Wojtal, Kacper A; Fischbeck-Terhalle, Anne; Frey-Wagner, Isabelle; Hausmann, Martin; Kraemer, Thomas; Rogler, Gerhard

    2017-07-01

    Western lifestyle and diet are major environmental factors playing a role in the development of IBD. Titanium dioxide (TiO 2 ) nanoparticles are widely used as food additives or in pharmaceutical formulations and are consumed by millions of people on a daily basis. We investigated the effects of TiO 2 in the development of colitis and the role of the nucleotide-binding oligomerisation domain receptor, pyrin domain containing (NLRP)3 inflammasome. Wild-type and NLRP3-deficient mice with dextran sodium sulfate-induced colitis were orally administered with TiO 2 nanoparticles. The proinflammatory effects of TiO 2 particles in cultured human intestinal epithelial cells (IECs) and macrophages were also studied, as well as the ability of TiO 2 crystals to traverse IEC monolayers and accumulate in the blood of patients with IBD using inductively coupled plasma mass spectrometry. Oral administration of TiO 2 nanoparticles worsened acute colitis through a mechanism involving the NLRP3 inflammasome. Importantly, crystals were found to accumulate in spleen of TiO 2 -administered mice. In vitro, TiO 2 particles were taken up by IECs and macrophages and triggered NLRP3-ASC-caspase-1 assembly, caspase-1 cleavage and the release of NLRP3-associated interleukin (IL)-1β and IL-18. TiO 2 also induced reactive oxygen species generation and increased epithelial permeability in IEC monolayers. Increased levels of titanium were found in blood of patients with UC having active disease. These findings indicate that individuals with a defective intestinal barrier function and pre-existing inflammatory condition, such as IBD, might be negatively impacted by the use of TiO 2 nanoparticles. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  5. Exposure to titanium dioxide and other metallic oxide nanoparticles induces cytotoxicity on human neural cells and fibroblasts

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    James C K Lai

    2008-12-01

    Full Text Available James C K Lai1, Maria B Lai1, Sirisha Jandhyam1, Vikas V Dukhande1, Alok Bhushan1, Christopher K Daniels1, Solomon W Leung21Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, and Biomedical Research Institute; 2Department of Civil and Environmental Engineering, College of Engineering and Biomedical Research Institute, Idaho State University, Pocatello, ID, USAAbstract: The use of titanium dioxide (TiO2 in various industrial applications (eg, production of paper, plastics, cosmetics, and paints has been expanding thereby increasing the occupational and other environmental exposure of these nanoparticles to humans and other species. However, the health effects of exposure to TiO2 nanoparticles have not been systematically assessed even though recent studies suggest that such exposure induces inflammatory responses in lung tissue and cells. Because the effects of such nanoparticles on human neural cells are unknown, we have determined the putative cytotoxic effects of these nanoparticles on human astrocytes-like astrocytoma U87 cells and compared their effects on normal human fibroblasts. We found that TiO2 micro- and nanoparticles induced cell death on both human cell types in a concentration-related manner. We further noted that zinc oxide (ZnO nanoparticles were the most effective, TiO2 nanoparticles the second most effective, and magnesium oxide (MgO nanoparticles the least effective in inducing cell death in U87 cells. The cell death mechanisms underlying the effects of TiO2 micro- and nanoparticles on U87 cells include apoptosis, necrosis, and possibly apoptosis-like and necrosis-like cell death types. Thus, our findings may have toxicological and other pathophysiological implications on exposure of humans and other mammalian species to metallic oxide nanoparticles.Keywords: cytotoxicity of titanium dioxide micro- and nanoparticles, cytotoxicity of zinc oxide and magnesium oxide nanoparticles, human neural cells

  6. Titanium dioxide nanoparticle-induced cytotoxicity and the underlying mechanism in mouse myocardial cells

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    Zhou, Yingjun; Hong, Fashui; Wang, Ling

    2017-11-01

    Exposure to fine particulate matter (PM) is known to cause cardiovascular disease. While extensive research has focused on the risk of atmospheric PM to public health, particularly heart disease, limited studies to date have attempted to clarify the molecular mechanisms underlying myocardial cell damage caused by exposure to titanium dioxide nanoparticles (TiO2 NPs). Data from the current investigation showed that TiO2 NPs are deposited in myocardial mitochondria via the blood circulation accompanied by obvious ultrastructural changes and impairment of mitochondrial structure and function in mouse myocardial cells, including reduction in mitochondrial membrane potential and ATP production, aggravation of oxidative stress along with increased levels of reactive oxygen species, malondialdehyde and protein carbonyl, and decreased glutathione content and enzymatic activities, including superoxide dismutase and glutathione peroxidase. Furthermore, TiO2 NPs induced a significant decrease in the activities of complex I, complex II, complex III, complex IV, succinate dehydrogenase, NADH oxidase, Ca2+-ATPase, Na+/K+-ATPase, and Ca2+/Mg2+-ATPase, and upregulation of cytokine expression (including cytochrome c, caspase-3, and p-JNK) in mitochondria-mediated apoptosis while downregulating Bcl-2 expression in mouse myocardial cells. Our results collectively indicate that chronic exposure to TiO2 NPs induces damage in mitochondrial structure and function as well as mitochondria-mediated apoptosis in mouse myocardial cells, which may be closely associated with heart disease in animals and humans.

  7. Titanium dioxide nanoparticles inhibit proliferation and induce morphological changes and apoptosis in glial cells

    International Nuclear Information System (INIS)

    Márquez-Ramírez, Sandra Gissela; Delgado-Buenrostro, Norma Laura; Chirino, Yolanda Irasema; Iglesias, Gisela Gutiérrez; López-Marure, Rebeca

    2012-01-01

    Titanium dioxide nanoparticles (TiO 2 NPs) are widely used in the chemical, electrical and electronic industries. TiO 2 NPs can enter directly into the brain through the olfactory bulb and be deposited in the hippocampus region. We determined the effect of TiO 2 NPs on rat and human glial cells, C6 and U373, respectively. We evaluated proliferation by crystal violet staining, internalization of TiO 2 NPs, and cellular morphology by TEM analysis, as well as F-actin distribution by immunostaining and cell death by detecting active caspase-3 and DNA fragmentation. TiO 2 NPs inhibited proliferation and induced morphological changes that were related with a decrease in immuno-location of F-actin fibers. TiO 2 NPs were internalized and formation of vesicles was observed. TiO 2 NPs induced apoptosis after 96 h of treatment. Hence, TiO 2 NPs had a cytotoxic effect on glial cells, suggesting that exposure to TiO 2 NPs could cause brain injury and be hazardous to health.

  8. Effect of natural organic matter on the photo-induced toxicity of titanium dioxide nanoparticles.

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    Wormington, Alexis M; Coral, Jason; Alloy, Matthew M; Delmarè, Carmen L; Mansfield, Charles M; Klaine, Stephen J; Bisesi, Joseph H; Roberts, Aaron P

    2017-06-01

    Nano-titanium dioxide (TiO 2 ) is the most widely used form of nanoparticles in commercial industry and comes in 2 main configurations: rutile and anatase. Rutile TiO 2 is used in ultraviolet (UV) screening applications, whereas anatase TiO 2 crystals have a surface defect that makes them photoreactive. There are numerous reports in the literature of photo-induced toxicity to aquatic organisms following coexposure to anatase nano-TiO 2 and UV. All natural freshwater contains varying amounts of natural organic matter (NOM), which can drive UV attenuation and quench reactive oxygen species (ROS) in aquatic ecosystems. The present research examined how NOM alters the photo-induced toxicity of anatase nano-TiO 2 . Daphnia magna neonates were coexposed to NOM and photoexcited anatase nano-TiO 2 for 48 h. Natural organic matter concentrations as low as 4 mg/L reduced anatase nano-TiO 2 toxicity by nearly 100%. These concentrations of NOM attenuated UV by <10% in the exposure system. However, ROS production measured using a fluorescence assay was significantly reduced in a NOM concentration--dependent manner. Taken together, these data suggest that NOM reduces anatase nano-TiO 2 toxicity via an ROS quenching mechanism and not by attenuation of UV. Environ Toxicol Chem 2017;36:1661-1666. © 2016 SETAC. © 2016 SETAC.

  9. Comparison of the Thrapeutic Effcts of Silymarin and Nanosilymarin on Hepatotoxicity Induced by Titanium Dioxide Nanoparticles

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    Hajizadeh Moghaddam A

    2017-03-01

    Full Text Available Introduction: Recent studies have indicated that titanium dioxide nanoparticles (TiO2 NPs are toxic for human. Silymarin is a well-known hepatoprotective drug. In this study, the nanoprecipitation technique was used for nanocrystals to improve the solubility of silymarin. Th aim of this study was to analyze the protective role of silymarin and its nanocrystal on liver damage due to TiO2 NPs in rat. Methods: In this experimental study, rats were divided to fie groups in separate cages: Control, vehicle, toxic group (150 mg/kg TiO2 NPs for three weeks orally as well as silymarin and silymarin NPs groups (100 mg/kg for three weeks orally aftr TiO2 NPs administration. Thn, the serum level of aspartate transaminase (AST, alanine transaminase (ALT and alkaline phosphatase (ALP as well as the liver histological changes were investigated. Results: Oral administration of Tio2 NPs resulted in signifiantly elevated levels of ALT, AST and ALP of serum and signifiantly increased the core diameter of hepatocytes (P > 0.05. Silymarin and its nanocrystal reduced the elevated liver enzyme levels and also decreased the core diameter of hepatocytes in toxic rats (P > 0.001. Conclusion: Th results from the present study indicated that silymarin and its nanocrystal probably due to antioxidant effcts cause hepatoprotective against TiO2 NPs-induced liver injury.

  10. Tiron ameliorates oxidative stress and inflammation in titanium dioxide nanoparticles induced nephrotoxicity of male rats.

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    Morgan, Ashraf; Galal, Mona K; Ogaly, Hanan A; Ibrahim, Marwa A; Abd-Elsalam, Reham M; Noshy, Peter

    2017-09-01

    Although the widespread use of titanium dioxide nanoparticles (TiO 2 NPs), few studies were conducted on its hazard influence on human health. Tiron a synthetic vitamin E analog was proven to be a mitochondrial targeting antioxidant. The current investigation was performed to assess the efficacy of tiron against TiO 2 NPs induced nephrotoxicity. Eighty adult male rats divided into four different groups were used: group I was the control, group II received TiO2 NPs (100mg\\Kg BW), group III received TiO2 NPs plus tiron (470mg\\kg BW), and group IV received tiron alone. Urea, creatinine and total protein concentrations were measured in serum to assess the renal function. Antioxidant status was estimated by determining the activities of glutathione peroxidase, superoxide dismutase, malondialdehyde (MDA) level and glutathione concentration in renal tissue. As well as Renal fibrosis was evaluated though measuring of transforming growth factor-β1 (TGFβ1) and matrix metalloproteinase 9 (MMP9) expression levels and histopathological examination. TiO 2 NPs treated rats showed marked elevation of renal indices, depletion of renal antioxidant enzymes with marked increase in MDA concentration as well as significant up-regulation in fibrotic biomarkers TGFβ1 and MMP9. Oral administration of tiron to TiO 2 NPs treated rats significantly attenuate the renal dysfunction through decreasing of renal indices, increasing of antioxidant enzymes activities, down-regulate the expression of fibrotic genes and improving the histopathological picture for renal tissue. In conclusion, tiron was proved to attenuate the nephrotoxicity induced by TiO 2 NPs through its radical scavenging and metal chelating potency. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Titanium dioxide nanoparticle-induced dysfunction of cardiac hemodynamics is involved in cardiac inflammation in mice.

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    Hong, Fashui; Wu, Nan; Zhao, Xiangyu; Tian, Yusheng; Zhou, Yingjun; Chen, Ting; Zhai, Yanyu; Ji, Li

    2016-12-01

    In the past two decades, titanium dioxide nanoparticles (TiO 2 NPs) have been extensively used in medicine, food industry and other daily life, while their possible interactions with the their influence and human body on human health remain not well understood. Thus, the study was designed to examine whether long-term exposure to TiO 2 NPs cause myocardial dysfunction which is involved in cardiac lesions and alter expression of genes and proteins involving inflammatory response in the mouse heart. The findings showed that intragastric feeding for nine consecutive months with TiO 2 NPs resulted in titanium accumulation, infiltration of inflammatory cells and apoptosis of heart, reductions in net increases of body weight, cardiac indices of function (LV systolic pressure, maximal rate of pressure increase over time, maximal rate of pressure decrease over time and coronary flow), and increases in heart indices, cardiac indices of function (LV end-diastolic pressure and heart rate) in mice. TiO 2 NPs also decreased ATP production in the hearts. Furthermore, TiO 2 NPs increased expression of nuclear factor-κB, interleukin-lβ and tumour necrosis factor-α, and reduced expression of anti-inflammatory cytokines including suppressor of cytokine signaling (SOCS) 1 and SOCS3 in the cardiac tissue. These results suggest that TiO 2 NPs may modulate the cardiac function and expression of inflammatory cytokines. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2917-2927, 2016. © 2016 Wiley Periodicals, Inc.

  12. Titanium dioxide nanoparticles induce oxidative stress and DNA-adduct formation but not DNA-breakage in human lung cells

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    Schins Roel PF

    2009-06-01

    Full Text Available Abstract Titanium dioxide (TiO2, also known as titanium (IV oxide or anatase, is the naturally occurring oxide of titanium. It is also one of the most commercially used form. To date, no parameter has been set for the average ambient air concentration of TiO2 nanoparticles (NP by any regulatory agency. Previously conducted studies had established these nanoparticles to be mainly non-cyto- and -genotoxic, although they had been found to generate free radicals both acellularly (specially through photocatalytic activity and intracellularly. The present study determines the role of TiO2-NP (anatase, ∅ in vitro. For comparison, iron containing nanoparticles (hematite, Fe2O3, ∅ 2-NP did not induce DNA-breakage measured by the Comet-assay in both cell types. Generation of reactive oxygen species (ROS was measured acellularly (without any photocatalytic activity as well as intracellularly for both types of particles, however, the iron-containing NP needed special reducing conditions before pronounced radical generation. A high level of DNA adduct formation (8-OHdG was observed in IMR-90 cells exposed to TiO2-NP, but not in cells exposed to hematite NP. Our study demonstrates different modes of action for TiO2- and Fe2O3-NP. Whereas TiO2-NP were able to generate elevated amounts of free radicals, which induced indirect genotoxicity mainly by DNA-adduct formation, Fe2O3-NP were clastogenic (induction of DNA-breakage and required reducing conditions for radical formation.

  13. Titanium dioxide nanoparticles induce an adaptive inflammatory response and invasion and proliferation of lung epithelial cells in chorioallantoic membrane

    International Nuclear Information System (INIS)

    Medina-Reyes, Estefany I.; Déciga-Alcaraz, Alejandro; Freyre-Fonseca, Verónica; Delgado-Buenrostro, Norma L.; Flores-Flores, José O.; Gutiérrez-López, Gustavo F.; Sánchez-Pérez, Yesennia; García-Cuéllar, Claudia M.

    2015-01-01

    Titanium dioxide nanoparticles (TiO 2 NPs) studies have been performed using relatively high NPs concentration under acute exposure and limited studies have compared shape effects. We hypothesized that midterm exposure to low TiO 2 NPs concentration in lung epithelial cells induces carcinogenic characteristics modulated partially by NPs shape. To test our hypothesis we synthesized NPs shaped as belts (TiO 2 -B) using TiO 2 spheres (TiO 2 -SP) purchased from Sigma Aldrich Co. Then, lung epithelial A549 cells were low-exposed (10 µg/cm 2 ) to both shapes during 7 days and internalization, cytokine release and invasive potential were determined. Results showed greater TiO 2 -B effect on agglomerates size, cell size and granularity than TiO 2 -SP. Agglomerates size in cell culture medium was 310 nm and 454 nm for TiO 2 -SP and TiO 2 -B, respectively; TiO 2 -SP and TiO 2 -B induced 23% and 70% cell size decrease, respectively, whilst TiO 2 -SP and TiO 2 -B induced 7 and 14-fold of granularity increase. NO x production was down-regulated (31%) by TiO 2 -SP and up-regulated (70%) by TiO 2 -B. Both NPs induced a transient cytokine release (IL-2, IL-6, IL-8, IL-4, IFN-γ, and TNF-α) after 4 days, but cytokines returned to basal levels in TiO 2 -SP exposed cells while TiO 2 -B induced a down-regulation after 7 days. Midterm exposure to both shapes of NPs induced capability to degrade cellular extracellular matrix components from chorioallantoic membrane and Ki-67 marker showed that TiO 2 -B had higher proliferative potential than TiO 2 -SP. We conclude that midterm exposure to low NPs concentration of NPs has an impact in the acquisition of new characteristics of exposed cells and NPs shape influences cellular outcome. - Graphical abstract: (A) Lung epithelial cells were low exposed (below 10 µg/cm 2 ) to titanium dioxide nanoparticles (TiO 2 -NPs) shaped as spheres (TiO 2 -SP) and belts (TiO 2 -B) for midterm (7 continuous days) separately. (B) Then, cells from each cell

  14. Titanium dioxide nanoparticles induce an adaptive inflammatory response and invasion and proliferation of lung epithelial cells in chorioallantoic membrane

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    Medina-Reyes, Estefany I.; Déciga-Alcaraz, Alejandro [Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, CP 54059 Estado de México (Mexico); Freyre-Fonseca, Verónica [Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, CP 54059 Estado de México (Mexico); Doctorado en Ciencias en Alimentos, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, CP 11340 México, DF (Mexico); Delgado-Buenrostro, Norma L. [Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, CP 54059 Estado de México (Mexico); Flores-Flores, José O. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria AP 70-186, CP 04510 México, DF (Mexico); Gutiérrez-López, Gustavo F. [Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, CP 11340 México, DF (Mexico); Sánchez-Pérez, Yesennia; García-Cuéllar, Claudia M. [Instituto Nacional de Cancerología, Subdirección de Investigación Básica, San Fernando 22, Tlalpan, CP 14080 México, DF (Mexico); and others

    2015-01-15

    Titanium dioxide nanoparticles (TiO{sub 2} NPs) studies have been performed using relatively high NPs concentration under acute exposure and limited studies have compared shape effects. We hypothesized that midterm exposure to low TiO{sub 2} NPs concentration in lung epithelial cells induces carcinogenic characteristics modulated partially by NPs shape. To test our hypothesis we synthesized NPs shaped as belts (TiO{sub 2}-B) using TiO{sub 2} spheres (TiO{sub 2}-SP) purchased from Sigma Aldrich Co. Then, lung epithelial A549 cells were low-exposed (10 µg/cm{sup 2}) to both shapes during 7 days and internalization, cytokine release and invasive potential were determined. Results showed greater TiO{sub 2}-B effect on agglomerates size, cell size and granularity than TiO{sub 2}-SP. Agglomerates size in cell culture medium was 310 nm and 454 nm for TiO{sub 2}-SP and TiO{sub 2}-B, respectively; TiO{sub 2}-SP and TiO{sub 2}-B induced 23% and 70% cell size decrease, respectively, whilst TiO{sub 2}-SP and TiO{sub 2}-B induced 7 and 14-fold of granularity increase. NO{sub x} production was down-regulated (31%) by TiO{sub 2}-SP and up-regulated (70%) by TiO{sub 2}-B. Both NPs induced a transient cytokine release (IL-2, IL-6, IL-8, IL-4, IFN-γ, and TNF-α) after 4 days, but cytokines returned to basal levels in TiO{sub 2}-SP exposed cells while TiO{sub 2}-B induced a down-regulation after 7 days. Midterm exposure to both shapes of NPs induced capability to degrade cellular extracellular matrix components from chorioallantoic membrane and Ki-67 marker showed that TiO{sub 2}-B had higher proliferative potential than TiO{sub 2}-SP. We conclude that midterm exposure to low NPs concentration of NPs has an impact in the acquisition of new characteristics of exposed cells and NPs shape influences cellular outcome. - Graphical abstract: (A) Lung epithelial cells were low exposed (below 10 µg/cm{sup 2}) to titanium dioxide nanoparticles (TiO{sub 2}-NPs) shaped as spheres (TiO{sub 2

  15. CdS nanoparticle sensitized titanium dioxide decorated graphene for enhancing visible light induced photoanode

    International Nuclear Information System (INIS)

    Yousefzadeh, S.; Faraji, M.; Nien, Y.T.; Moshfegh, A.Z.

    2014-01-01

    Highlights: • CdS nanoparticles were deposited on TiO 2 /graphene film by different SILAR cycles. • The visible light absorption increased due to graphene and CdS nanoparticles. • The highest photocurrent density was achieved for nanocomposite with 30 CdS cycles. • A mechanism has been suggested for nanocomposite photoanodes, significantly. - Abstract: CdS/TiO 2 /graphene (CTG) nanocomposite thin films were synthesized by a facile production route. The TiO 2 /graphene (TG) nanocomposite was initially fabricated by sol-gel method in such a way that TiO 2 nanoparticles loaded on graphene oxide (GO) sheet via photocatalytic process. Then, CdS nanoparticles were deposited on the TG thin film by successive ion layer adsorption and reaction process (SILAR) approach. Based on atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the TG thin film possessed a larger surface area as compared with the pure TiO 2 thin film due to presence of graphene sheet. UV/visible spectroscopy exhibited that visible absorption of the CTG samples increased with increasing CdS SILAR deposition cycle (n). Enhanced photocurrent response of the CTG(n) photoanodes measured as compared with the TG and T photoanodes due to good electrical conductivity and large surface area of graphene as well as the visible light-harvesting ability of CdS nanoparticles. Maximum photocurrent density of about 4.5 A/m 2 and electron life time of about 5 s was measured for the CTG(30) photoanodes

  16. CdS nanoparticle sensitized titanium dioxide decorated graphene for enhancing visible light induced photoanode

    Energy Technology Data Exchange (ETDEWEB)

    Yousefzadeh, S.; Faraji, M. [Physics Department, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Nien, Y.T. [Department of Materials Science and Engineering, National Formosa University, Taiwan (China); Moshfegh, A.Z., E-mail: moshfegh@sharif.edu [Physics Department, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 14588-89694, Tehran (Iran, Islamic Republic of)

    2014-11-30

    Highlights: • CdS nanoparticles were deposited on TiO{sub 2}/graphene film by different SILAR cycles. • The visible light absorption increased due to graphene and CdS nanoparticles. • The highest photocurrent density was achieved for nanocomposite with 30 CdS cycles. • A mechanism has been suggested for nanocomposite photoanodes, significantly. - Abstract: CdS/TiO{sub 2}/graphene (CTG) nanocomposite thin films were synthesized by a facile production route. The TiO{sub 2}/graphene (TG) nanocomposite was initially fabricated by sol-gel method in such a way that TiO{sub 2} nanoparticles loaded on graphene oxide (GO) sheet via photocatalytic process. Then, CdS nanoparticles were deposited on the TG thin film by successive ion layer adsorption and reaction process (SILAR) approach. Based on atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the TG thin film possessed a larger surface area as compared with the pure TiO{sub 2} thin film due to presence of graphene sheet. UV/visible spectroscopy exhibited that visible absorption of the CTG samples increased with increasing CdS SILAR deposition cycle (n). Enhanced photocurrent response of the CTG(n) photoanodes measured as compared with the TG and T photoanodes due to good electrical conductivity and large surface area of graphene as well as the visible light-harvesting ability of CdS nanoparticles. Maximum photocurrent density of about 4.5 A/m{sup 2} and electron life time of about 5 s was measured for the CTG(30) photoanodes.

  17. Reduction of DNA damage induced by titanium dioxide nanoparticles through Nrf2 in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Zhiqin [Department of Toxicology, Hebei Medical University, Shijiazhuang (China); Department of Laboratory Diagnosis, Hebei Medical University, Shijiazhuang (China); Niu, Yujie [Department of Occupational Health and Environmental Health, Hebei Medical University, Shijiazhuang (China); Wang, Qian [Department of Toxicology, Hebei Medical University, Shijiazhuang (China); Shi, Lei [Department of Occupational Health and Environmental Health, Hebei Medical University, Shijiazhuang (China); Guo, Huicai; Liu, Yi; Zhu, Yue [Department of Toxicology, Hebei Medical University, Shijiazhuang (China); Liu, Shufeng; Liu, Chao [Hebei Keylab of Laboratory Animal Science, Shijiazhuang (China); Chen, Xin [Xiumen Community Health Service Centre, Shijiazhuang (China); Zhang, Rong, E-mail: rongzhang@hebmu.edu.cn [Department of Toxicology, Hebei Medical University, Shijiazhuang (China); Hebei Keylab of Laboratory Animal Science, Shijiazhuang (China)

    2015-11-15

    Highlights: • Nrf2 signals were partly responsible for the DNA damage induced by Nano-TiO{sub 2}. • Nrf2 loss could aggravate the DNA damage induced by Nano-TiO{sub 2}. • Acquired Nrf2 decreased the susceptibility to DNA damage induced by Nano-TiO{sub 2}. - Abstract: Titanium dioxide nanoparticles (Nano-TiO{sub 2}) are widely used to additives in cosmetics, pharmaceutical, paints and foods. Recent studies have demonstrated that Nano-TiO{sub 2} induces DNA damage and increased the risk of cancer and the mechanism might relate with oxidative stress. The aim of this study was to evaluate the effects of Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), an anti-oxidative mediator, on DNA damage induced by Nano-TiO{sub 2}. Wildtype, Nrf2 knockout (Nrf2(-/-)) and tert-butylhydroquinone (tBHQ) pre-treated HepG2 cells and mice were treated with Nano-TiO{sub 2}. And then the oxidative stress and DNA damage were evaluated. Our data showed that DNA damage, reactive oxygen species (ROS) generation and MDA content in Nano-TiO{sub 2} exposed cells were significantly increased than those of control in dose dependent manners. Nrf2/ARE droved the downstream genes including NAD(P)H dehydrogenase [quinine] 1(NQO1), heme oxygenase 1 (HO-1) and glutamate-cysteine ligase catalytic subunit (GCLC) expression were significantly higher in wildtype HepG2 cells after Nano-TiO{sub 2} treatment. After treatment with Nano-TiO{sub 2}, the DNA damages were significantly increased in Nrf(-/-) cells and mice whereas significantly decreased in tBHQ pre-treatment cells and mice, compared with the wildtype HepG2 cells and mice, respectively. Our results indicated that the acquired of Nrf2 leads to a decreased susceptibility to DNA damages induction by Nano-TiO{sub 2} and decreasing of risk of cancer which would provide a strategy for a more efficacious sensitization of against of Nano-TiO{sub 2} toxication.

  18. Intragastric exposure to titanium dioxide nanoparticles induced nephrotoxicity in mice, assessed by physiological and gene expression modifications

    Science.gov (United States)

    2013-01-01

    Background Numerous studies have demonstrated that titanium dioxide nanoparticles (TiO2 NPs) induced nephrotoxicity in animals. However, the nephrotoxic multiple molecular mechanisms are not clearly understood. Methods Mice were exposed to 2.5, 5 and 10 mg/kg TiO2 NPs by intragastric administration for 90 consecutive days, and their growth, element distribution, and oxidative stress in kidney as well as kidney gene expression profile were investigated using whole-genome microarray analysis technique. Results Our findings suggest that TiO2 NPs resulted in significant reduction of renal glomerulus number, apoptosis, infiltration of inflammatory cells, tissue necrosis or disorganization of renal tubules, coupled with decreased body weight, increased kidney indices, unbalance of element distribution, production of reactive oxygen species and peroxidation of lipid, protein and DNA in mouse kidney tissue. Furthermore, microarray analysis showed significant alterations in the expression of 1, 246 genes in the 10 mg/kg TiO2 NPs-exposed kidney. Of the genes altered, 1006 genes were associated with immune/inflammatory responses, apoptosis, biological processes, oxidative stress, ion transport, metabolic processes, the cell cycle, signal transduction, cell component, transcription, translation and cell differentiation, respectively. Specifically, the vital up-regulation of Bcl6, Cfi and Cfd caused immune/ inflammatory responses, the significant alterations of Axud1, Cyp4a12a, Cyp4a12b, Cyp4a14, and Cyp2d9 expression resulted in severe oxidative stress, and great suppression of Birc5, Crap2, and Tfrc expression led to renal cell apoptosis. Conclusions Axud1, Bcl6, Cf1, Cfd, Cyp4a12a, Cyp4a12b, Cyp2d9, Birc5, Crap2, and Tfrc may be potential biomarkers of kidney toxicity caused by TiO2 NPs exposure. PMID:23406204

  19. Titanium dioxide nanoparticles cause genotoxicity in human lung epithelial cells

    Science.gov (United States)

    The use of engineered nanoparticles in consumer products is steadily increasing. However, the health effects of exposure to these nanoparticles are not thoroughly understood. This study investigated the genotoxicity of six titanium dioxide and two cerium oxide nanoparticles of va...

  20. Internalisation of hybrid titanium dioxide/para-amino benzoic acid nanoparticles in human dendritic cells did not induce toxicity and changes in their functions.

    Science.gov (United States)

    Migdal, Camille; Rahal, Raed; Rubod, Alain; Callejon, Sylvie; Colomb, Evelyne; Atrux-Tallau, Nicolas; Haftek, Marek; Vincent, Claude; Serres, Mireille; Daniele, Stéphane

    2010-11-10

    Nanoparticles (NPs) have been reported to penetrate into human skin through lesional skin or follicular structures. Therefore, their ability to interact with dendritic cell (DC) was investigated using DCs generated from monocytes (mono-DCs). Hybrid titanium dioxide/para-amino benzoic acid (TiO(2)/PABA) NPs did not induce any cell toxicity. NPs were internalised into DCs through macropinocytosis and not by a receptor-mediated mechanism. Confocal microscopy showed that NPs were not detected in the nucleus. These data are confirmed by electronic microscopy which demonstrated that hybrid NPs were rapidly in contact with cellular membrane and localised into cytoplasmic vesicles without colocalisation with clathrin-coated vesicles. Hybrid NPs did not induce CD86 or HLA-DR overexpression or cytokine secretion (IL-8 and TNF-α) indicating no DC activation. Internalisation of hybrid NPs did not modify DC response towards sensitisers such as nickel and thimerosal or LPS used as positive controls. Moreover, hybrid NPs did not induce any oxidative stress implicated in DC activation process. After mono-DC irradiation by ultraviolet A (UVA), hybrid NP-treated cells did not produce UVA-induced reactive oxygen species (ROS) and exhibited a better cell viability compared with UVA-irradiated control cells, suggesting a protecting effect of hybrid TiO(2)/PABA NPs against UVA-induced ROS. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  1. Titanium Dioxide Nanoparticles Induce Endoplasmic Reticulum Stress-Mediated Autophagic Cell Death via Mitochondria-Associated Endoplasmic Reticulum Membrane Disruption in Normal Lung Cells

    Science.gov (United States)

    Yu, Kyeong-Nam; Chang, Seung-Hee; Park, Soo Jin; Lim, Joohyun; Lee, Jinkyu; Yoon, Tae-Jong; Kim, Jun-Sung; Cho, Myung-Haing

    2015-01-01

    Nanomaterials are used in diverse fields including food, cosmetic, and medical industries. Titanium dioxide nanoparticles (TiO2-NP) are widely used, but their effects on biological systems and mechanism of toxicity have not been elucidated fully. Here, we report the toxicological mechanism of TiO2-NP in cell organelles. Human bronchial epithelial cells (16HBE14o-) were exposed to 50 and 100 μg/mL TiO2-NP for 24 and 48 h. Our results showed that TiO2-NP induced endoplasmic reticulum (ER) stress in the cells and disrupted the mitochondria-associated endoplasmic reticulum membranes (MAMs) and calcium ion balance, thereby increasing autophagy. In contrast, an inhibitor of ER stress, tauroursodeoxycholic acid (TUDCA), mitigated the cellular toxic response, suggesting that TiO2-NP promoted toxicity via ER stress. This novel mechanism of TiO2-NP toxicity in human bronchial epithelial cells suggests that further exhaustive research on the harmful effects of these nanoparticles in relevant organisms is needed for their safe application. PMID:26121477

  2. Downregulation of B-cell lymphoma/leukemia-2 by overexpressed microRNA 34a enhanced titanium dioxide nanoparticle-induced autophagy in BEAS-2B cells

    Science.gov (United States)

    Bai, Wenlin; Chen, Yujiao; Sun, Pengling; Gao, Ai

    2016-01-01

    Titanium dioxide (TiO2) nanoparticles (TNPs) are manufactured worldwide for a wide range of applications and the toxic effect of TNPs on biological systems is gaining attention. Autophagy is recognized as an emerging toxicity mechanism triggered by nanomaterials. MicroRNA 34a (miR34a) acts as a tumor suppressor gene by targeting many oncogenes, but how it affects autophagy induced by TNPs is not completely understood. Here, we observed the activation of TNP-induced autophagy through monodansylcadaverine staining and LC3-I/LC3-II conversion. Meanwhile, the transmission electron microscope ultrastructural analysis showed typical morphological characteristics in autophagy process. We detected the expression of miR34a and B-cell lymphoma/leukemia-2 (Bcl-2). In addition, the underlying mechanism of TNP-induced autophagy was performed using overexpression of miR34a by lentivirus vector transfection. Results showed that TNPs induced autophagy generation evidently. Typical morphological changes in the process of autophagy were observed by the transmission electron microscope ultrastructural analysis and LC3-I/LC3-II conversion increased significantly in TNP-treated cells. Meanwhile, TNPs induced the downregulation of miR34a and increased the expression of Bcl-2. Furthermore, overexpressed miR34a decreased the expression of Bcl-2 both in messenger RNA and protein level, following which the level of autophagy and cell death rate increased after the transfected cells were incubated with TNPs for 24 hours. These findings provide the first evidence that overexpressed miR34a enhanced TNP-induced autophagy and cell death through targeted downregulation of Bcl-2 in BEAS-2B cells. PMID:27226226

  3. Role of the crystalline form of titanium dioxide nanoparticles: Rutile, and not anatase, induces toxic effects in Balb/3T3 mouse fibroblasts.

    Science.gov (United States)

    Uboldi, Chiara; Urbán, Patricia; Gilliland, Douglas; Bajak, Edyta; Valsami-Jones, Eugenia; Ponti, Jessica; Rossi, François

    2016-03-01

    The wide use of titanium dioxide nanoparticles (TiO2 NPs) in industrial applications requires the investigation of their effects on human health. In this context, we investigated the effects of nanosized and bulk titania in two different crystalline forms (anatase and rutile) in vitro. By colony forming efficiency assay, a dose-dependent reduction of the clonogenic activity of Balb/3T3 mouse fibroblasts was detected in the presence of rutile, but not in the case of anatase NPs. Similarly, the cell transformation assay and the micronucleus test showed that rutile TiO2 NPs were able to induce type-III foci formation in Balb/3T3 cells and appeared to be slightly genotoxic, whereas anatase TiO2 NPs did not induce any significant neoplastic or genotoxic effect. Additionally, we investigated the interaction of TiO2 NPs with Balb/3T3 cells and quantified the in vitro uptake of titania using mass spectrometry. Results showed that the internalization was independent of the crystalline form of TiO2 NPs but size-dependent, as nano-titania were taken up more than their respective bulk materials. In conclusion, we demonstrated that the cytotoxic, neoplastic and genotoxic effects triggered in Balb/3T3 cells by TiO2 NPs depend on the crystalline form of the nanomaterial, whereas the internalization is regulated by the particle size. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Titanium dioxide nanoparticles relieve silk gland damage and increase cocooning of Bombyx mori under phoxim-induced toxicity.

    Science.gov (United States)

    Li, Bing; Yu, Xiaohong; Gui, Suxin; Xie, Yi; Hong, Jie; Zhao, Xiaoyang; Sheng, Lei; Sang, Xuezi; Sun, Qingqing; Wang, Ling; Shen, Weide; Hong, Fashui

    2013-12-18

    Organophosphate pesticides are applied widely in the world for agricultural purposes, and their exposures often resulted in non-cocooning of Bombyx mori in China. TiO2 nanoparticles have been demonstrated to increase pesticide resistance of Bombyx mori. While the toxicity of phoxim is well-documented, very limited information exists on the mechanisms of TiO2 nanoparticles improving the cocooning function of Bombyx mori following exposure to phoxim. The present study was, therefore, undertaken to determine whether TiO2 nanoparticles attenuate silk gland injury and elevate cocooning of B. mori following exposure to phoxim. The findings suggested that phoxim exposure resulted in severe damages of the silk gland structure and significantly decreased the cocooning in the silk gland of Bombyx mori. Furthermore, phoxim exposure significantly resulted in reductions of total protein concentrations and suppressed expressions of silk protein synthesis-related genes, including Fib-L, Fib-H, P25, Ser-2, and Ser-3, in the silk gland. TiO2 nanoparticle pretreatment, however, could significantly relieve silk gland injury of Bombyx mori. Importantly, TiO2 nanoparticles could remarkably elevate cocooning and total protein contents and promote expressions of Fib-L, Fib-H, P25, Ser-2, and Ser-3 in the silk gland following exposure to phoxim.

  5. Exposure to titanium dioxide and other metallic oxide nanoparticles induces cytotoxicity on human neural cells and fibroblasts

    OpenAIRE

    Leung, Solomon

    2008-01-01

    James C K Lai1, Maria B Lai1, Sirisha Jandhyam1, Vikas V Dukhande1, Alok Bhushan1, Christopher K Daniels1, Solomon W Leung21Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, and Biomedical Research Institute; 2Department of Civil and Environmental Engineering, College of Engineering and Biomedical Research Institute, Idaho State University, Pocatello, ID, USAAbstract: The use of titanium dioxide (TiO2) in various industrial applications (eg, production of paper, plast...

  6. Influence of photo-induced superhydrophilicity of titanium dioxide nanoparticles on the anti-fouling performance of ultrafiltration membranes

    Energy Technology Data Exchange (ETDEWEB)

    Madaeni, S.S., E-mail: smadaeni@yahoo.com [Membrane Research Center, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Ghaemi, N. [Membrane Research Center, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Department of Chemical Engineering, Kermanshah University of Technology, Kermanshah (Iran, Islamic Republic of); Alizadeh, A. [Nanoscience and Nanotechnology Research Centre (NNRC), Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Joshaghani, M. [Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of)

    2011-05-01

    Fouling is one of the most present prominent problems in almost all membrane processes. An increase in the membrane hydrophilicity is one of the effective ways to improve the membrane resistance to fouling. In this research, TiO{sub 2} nanoparticles were deposited on the surface of composite ultrafiltration (UF) membrane, and then irradiated by ultraviolet (UV) light. The coating of the membrane surface with TiO{sub 2} nanoparticles and radiation with (UV) light led to the considerable increase of hydrophilicity on the membrane surface. The deposition of TiO{sub 2} nanoparticles was carried out through coordinance bonds with OH functional groups of the polymer on the membrane surface. The flux through a coated and (UV) light radiated membrane was increased to a large extent compared to a virgin membrane. In this research, the effect of different concentrations of TiO{sub 2} nanoparticles in the presence and absence of (UV) irradiation was investigated, and the role of increasing of hydrophilicity on the anti-fouling property of membranes was studied. In order to characterize the membranes FTIR, XRD, SEM, water contact angle and cross-flow filtration were employed. This procedure is a useful technique for improvement of hydrophilicity to decrease (increase) fouling (anti-fouling performance) and enhance the permeation of membranes.

  7. Anatase titanium dioxide nanoparticles in mice: evidence for induced structural and functional sperm defects after short-, but not long-, term exposure

    Directory of Open Access Journals (Sweden)

    Michelle A Smith

    2015-04-01

    Full Text Available Titanium dioxide (TiO 2 nanoparticles (TNPs are widely used commercially and exist in a variety of products. To determine if anatase TNPs (ATNPs in doses smaller than previously used reach the scrotum after entry in the body at a distant location and induce sperm defects, 100% ATNP (2.5 or 5 mg kg−1 body weight was administered intraperitoneally to adult males for three consecutive days, followed by sacrifice 1, 2, 3, or 5 weeks later (long- or 24, 48 or 120 h (short-term exposure. Transmission electron microscopy revealed the presence of ANTP in scrotal adipose tissues collected 120 h postinjection when cytokine evaluation showed an inflammatory response in epididymal tissues and fluid. At 120 h and up to 3 weeks postinjection, testicular histology revealed enlarged interstitial spaces. Significantly increased numbers of terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling-positive (apoptotic germ (P = 0.002 and interstitial space cells (P = 0.04 were detected in treated males. Caudal epididymal sperm from the short-term, but not a long-term, arm showed significantly (P < 0.001 increased frequencies of flagellar abnormalities, excess residual cytoplasm (ERC, and unreacted acrosomes in treated versus controls (dose-response relationship. A novel correlation between ERC and unreacted acrosomes was uncovered. At 120 h, there were significant decreases in hyperactivated motility (P < 0.001 and mitochondrial membrane potential (P < 0.05, and increased reactive oxygen species levels (P < 0.00001 in treated versus control sperm. These results indicate that at 4-8 days postinjection, ANTP induce structural and functional sperm defects associated with infertility, and DNA damage via oxidative stress. Sperm defects were transient as they were not detected 10 days to 5 weeks postinjection.

  8. Anatase titanium dioxide nanoparticles in mice: evidence for induced structural and functional sperm defects after short-, but not long-, term exposure

    Science.gov (United States)

    Smith, Michelle A; Michael, Rowan; Aravindan, Rolands G; Dash, Soma; Shah, Syed I; Galileo, Deni S; Martin-DeLeon, Patricia A

    2015-01-01

    Titanium dioxide (TiO2) nanoparticles (TNPs) are widely used commercially and exist in a variety of products. To determine if anatase TNPs (ATNPs) in doses smaller than previously used reach the scrotum after entry in the body at a distant location and induce sperm defects, 100% ATNP (2.5 or 5 mg kg−1 body weight) was administered intraperitoneally to adult males for three consecutive days, followed by sacrifice 1, 2, 3, or 5 weeks later (long-) or 24, 48 or 120 h (short-term exposure). Transmission electron microscopy revealed the presence of ANTP in scrotal adipose tissues collected 120 h postinjection when cytokine evaluation showed an inflammatory response in epididymal tissues and fluid. At 120 h and up to 3 weeks postinjection, testicular histology revealed enlarged interstitial spaces. Significantly increased numbers of terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling-positive (apoptotic) germ (P = 0.002) and interstitial space cells (P = 0.04) were detected in treated males. Caudal epididymal sperm from the short-term, but not a long-term, arm showed significantly (P < 0.001) increased frequencies of flagellar abnormalities, excess residual cytoplasm (ERC), and unreacted acrosomes in treated versus controls (dose-response relationship). A novel correlation between ERC and unreacted acrosomes was uncovered. At 120 h, there were significant decreases in hyperactivated motility (P < 0.001) and mitochondrial membrane potential (P < 0.05), and increased reactive oxygen species levels (P < 0.00001) in treated versus control sperm. These results indicate that at 4–8 days postinjection, ANTP induce structural and functional sperm defects associated with infertility, and DNA damage via oxidative stress. Sperm defects were transient as they were not detected 10 days to 5 weeks postinjection. PMID:25370207

  9. Radiation induced sulfur dioxide removal

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    2000-01-01

    The biggest source of air pollution is the combustion of fossil fuels, were pollutants such as particulate, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and volatile organic compounds (VOC) are emitted. Among these pollutants, sulfur dioxide plays the main role in acidification of the environment. The mechanism of sulfur dioxide transformation in the environment is partly photochemical. This is not direct photooxidation, however, but oxidation through formed radicals. Heterogenic reactions play an important role in this transformation as well; therefore, observations from environmental chemistry can be used in air pollution control engineering. One of the most promising technologies for desulfurization of the flue gases (and simultaneous denitrification) is radiation technology with an electron accelerator application. Contrary to the nitrogen oxides (NO x ) removal processes, which is based on pure radiation induced reactions, sulfur dioxide removal depends on two pathways: a thermochemical reaction in the presence of ammonia/water vapor and a radiation set of radiochemical reactions. The mechanism of these reactions and the consequent technological parameters of the process are discussed in this paper. The industrial application of this radiation technology is being implemented in an industrial pilot plant operated by INCT at EPS Kaweczyn. A full-scale industrial plant is currently in operation in China, and two others are under development in Japan and Poland. (author)

  10. The immunomodulatory effects of titanium dioxide and silver nanoparticles.

    Science.gov (United States)

    Lappas, Courtney M

    2015-11-01

    Due to their characteristic physical, chemical and optical properties, titanium dioxide and silver nanoparticles are attractive tools for use in a wide range of applications. The use of nanoparticles for biological applications is, however, dependent upon their biocompatibility with living cells. Because of the importance of inflammation as a modulator of human health, the safe and efficacious in vivo use of titanium dioxide and silver nanoparticles is inherently linked to a favorable interaction with immune system cells. However, both titanium dioxide and silver nanoparticles have demonstrated potential to exert immunomodulatory and immunotoxic effects. Titanium dioxide and silver nanoparticles are readily internalized by immune system cells, may accumulate in peripheral lymphoid organs, and can influence multiple manifestations of immune cell activity. Although the factors influencing the biocompatibility of titanium dioxide and silver nanoparticles with immune system cells have not been fully elucidated, nanoparticle core composition, size, concentration and the duration of cell exposure seem to be important. Because titanium dioxide and silver nanoparticles are widely utilized in pharmaceutical, commercial and industrial products, it is vital that their effects on human health and immune system function be more thoroughly evaluated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Plasmon-induced selective carbon dioxide conversion on earth-abundant aluminum-cuprous oxide antenna-reactor nanoparticles.

    Science.gov (United States)

    Robatjazi, Hossein; Zhao, Hangqi; Swearer, Dayne F; Hogan, Nathaniel J; Zhou, Linan; Alabastri, Alessandro; McClain, Michael J; Nordlander, Peter; Halas, Naomi J

    2017-06-21

    The rational combination of plasmonic nanoantennas with active transition metal-based catalysts, known as 'antenna-reactor' nanostructures, holds promise to expand the scope of chemical reactions possible with plasmonic photocatalysis. Here, we report earth-abundant embedded aluminum in cuprous oxide antenna-reactor heterostructures that operate more effectively and selectively for the reverse water-gas shift reaction under milder illumination than in conventional thermal conditions. Through rigorous comparison of the spatial temperature profile, optical absorption, and integrated electric field enhancement of the catalyst, we have been able to distinguish between competing photothermal and hot-carrier driven mechanistic pathways. The antenna-reactor geometry efficiently harnesses the plasmon resonance of aluminum to supply energetic hot-carriers and increases optical absorption in cuprous oxide for selective carbon dioxide conversion to carbon monoxide with visible light. The transition from noble metals to aluminum based antenna-reactor heterostructures in plasmonic photocatalysis provides a sustainable route to high-value chemicals and reaffirms the practical potential of plasmon-mediated chemical transformations.Plasmon-enhanced photocatalysis holds promise for the control of chemical reactions. Here the authors report an Al@Cu 2 O heterostructure based on earth abundant materials to transform CO 2 into CO at significantly milder conditions.

  12. Trojan-Like Internalization of Anatase Titanium Dioxide Nanoparticles by Human Osteoblast Cells.

    Science.gov (United States)

    Ribeiro, A R; Gemini-Piperni, S; Travassos, R; Lemgruber, L; Silva, R C; Rossi, A L; Farina, M; Anselme, K; Shokuhfar, T; Shahbazian-Yassar, R; Borojevic, R; Rocha, L A; Werckmann, J; Granjeiro, J M

    2016-03-29

    Dentistry and orthopedics are undergoing a revolution in order to provide more reliable, comfortable and long-lasting implants to patients. Titanium (Ti) and titanium alloys have been used in dental implants and total hip arthroplasty due to their excellent biocompatibility. However, Ti-based implants in human body suffer surface degradation (corrosion and wear) resulting in the release of metallic ions and solid wear debris (mainly titanium dioxide) leading to peri-implant inflammatory reactions. Unfortunately, our current understanding of the biological interactions with titanium dioxide nanoparticles is still very limited. Taking this into consideration, this study focuses on the internalization of titanium dioxide nanoparticles on primary bone cells, exploring the events occurring at the nano-bio interface. For the first time, we report the selective binding of calcium (Ca), phosphorous (P) and proteins from cell culture medium to anatase nanoparticles that are extremely important for nanoparticle internalization and bone cells survival. In the intricate biological environment, anatase nanoparticles form bio-complexes (mixture of proteins and ions) which act as a kind of 'Trojan-horse' internalization by cells. Furthermore, anatase nanoparticles-induced modifications on cell behavior (viability and internalization) could be understand in detail. The results presented in this report can inspire new strategies for the use of titanium dioxide nanoparticles in several regeneration therapies.

  13. Far-ultraviolet spectral changes of titanium dioxide with gold nanoparticles by ultraviolet and visible light

    Science.gov (United States)

    Tanabe, Ichiro; Kurawaki, Yuji

    2018-05-01

    Attenuated total reflectance spectra including the far-ultraviolet (FUV, ≤ 200 nm) region of titanium dioxide (TiO2) with and without gold (Au) nanoparticles were measured. A newly developed external light-irradiation system enabled to observe spectral changes of TiO2 with Au nanoparticles upon light irradiations. Absorption in the FUV region decreased and increased by the irradiation with ultraviolet and visible light, respectively. These spectral changes may reflect photo-induced electron transfer from TiO2 to Au nanoparticles under ultraviolet light and from Au nanoparticles to TiO2 under visible light, respectively.

  14. Reduction of oxidative damages induced by titanium dioxide nanoparticles correlates with induction of the Nrf2 pathway by GSPE supplementation in mice.

    Science.gov (United States)

    Niu, Linpeng; Shao, Mengjiao; Liu, Yuan; Hu, Jinfeng; Li, Ruofan; Xie, Heran; Zhou, Lixiao; Shi, Lei; Zhang, Rong; Niu, Yujie

    2017-09-25

    Titanium dioxide nanoparticles (TiO 2 NPs) are widely used to additives in cosmetics, pharmaceuticals, paints and foods. Recent studies have demonstrated that TiO 2 NPs increased the risk of cancer and the mechanism might relate with oxidative stress. Grape seed procyanidin extract (GSPE) is a natural compound which has been demonstrated to possess a wide array of pharmacological and biochemical actions, including anti-inflammatory, anti-carcinogenic, and antioxidant properties. Our data show that GSPE prevents the changes of histopathology and biomarkers in heart, liver and kidney that occur in mice exposed to TiO 2 NPs. After pretreatment with GSPE, the DNA damage, reactive oxygen species (ROS) generation and malondialdehyde (MDA) content in mice exposed to TiO 2 NPs had statistically significant decreases in dose dependent manners. GSPE increased the expression of nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), NAD(P)H dehydrogenase[quinine] 1(NQO1), heme oxygenase 1 (HO-1) and glutamate-cysteine ligase catalytic subunit (GCLC). We conclude that grape seed procyanidin extract prevents the majority of tissue and molecular damage resulting from nanoparticle treatment. The protective effect of GSPE may be due to its strong antioxidative activities which related with the activated Nrf2 and its down-regulated genes including NQO1, HO-1 and GCLC. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Effect of Treatment Media on the Agglomeration of Titanium Dioxide Nanoparticles: Impact on Genotoxicity, Cellular Interaction, and Cell Cycle

    Science.gov (United States)

    ABSTRACT The widespread use of titanium dioxide (TiO2) nanoparticles in consumer products increases the probability of exposure to humans and the environment. Although TiO2 nanoparticles have been shown to induce DNA damage (comet assay) and chromosome damage (micronucleus ass...

  16. Investigation of titanium dioxide nanoparticles toxicity and uptake by plants

    Energy Technology Data Exchange (ETDEWEB)

    Larue, C; Carriere, M [Laboratoire de Structure et Dynamique par Resonance Magnetique UMR 9956 CEA-CNRS-IRAMIS, Gif-sur-Yvette (France); Khodja, H [Laboratoire d' Etude des Elements Legers, UMR 9956 CEA-CNRS-IRAMIS, Gif-sur-Yvette (France); Herlin-Boime, N [Laboratoire Francis Perrin URA 2453 CEA-CNRS-IRAMIS, 91191 Gif-sur-Yvette (France); Brisset, F [Institut de Chimie Moleculaire et des Materiaux d' Orsay, UMR8182 CNRS-University Paris sud, Orsay (France); Flank, A M [LUCIA beamline, SOLEIL synchrotron, Saint-Aubin (France); Fayard, B [Laboratoire de Physique du solide, Orsay, France and ID21 beamline, ESRF, Grenoble (France); Chaillou, S, E-mail: marie.carriere@cea.fr [Unite de Nutrition Azotee des Plantes, INRA, Versailles (France)

    2011-07-06

    Nanoparticles (NP) are introduced in a growing number of commercial products and their production may lead to their release in the environment. Plants may be a potential entry point for NP in the food chain. Up to now, results describing NP phytotoxical effects and plant accumulation are scarce and contradictory. To increase knowledge on titanium dioxide NP (TiO{sub 2}-NPs) accumulation and impact on plants, we designed a study on three plant species, namely wheat (Triticum aestivum), oilseed rape (Brassica napus) and Arabidopsis thaliana. These plants were exposed in hydroponics to a panel of well-characterized TiO{sub 2}-NPs, with diameters ranging from 12 to 140 nm, either anatase or rutile. Their accumulation in plant tissues is currently being assessed by complementary imaging techniques: scanning electron microscopy (SEM), transmission electron microscopy (TEM), micro-X-ray fluorescence (SR-{mu}-XRF) imaging and micro-particle induced X-ray emission ({mu}-PIXE) imaging. Moreover, the impact of TiO{sub 2}-NP exposure on germination rate, root elongation, dry biomass and evapotranspiration is evaluated. Preliminary results are presented here, with data collected on wheat plants exposed to 12 nm and 25 nm anatase TiO{sub 2}-NPs. These results show that TiO{sub 2}-NPs are taken up by plants, and do not significantly alter their germination and root elongation. These results underline the necessity of deeper evaluation of nanoparticle ecotoxicity, and particularly on their interaction with plants.

  17. Investigation of titanium dioxide nanoparticles toxicity and uptake by plants

    International Nuclear Information System (INIS)

    Larue, C; Carriere, M; Khodja, H; Herlin-Boime, N; Brisset, F; Flank, A M; Fayard, B; Chaillou, S

    2011-01-01

    Nanoparticles (NP) are introduced in a growing number of commercial products and their production may lead to their release in the environment. Plants may be a potential entry point for NP in the food chain. Up to now, results describing NP phytotoxical effects and plant accumulation are scarce and contradictory. To increase knowledge on titanium dioxide NP (TiO 2 -NPs) accumulation and impact on plants, we designed a study on three plant species, namely wheat (Triticum aestivum), oilseed rape (Brassica napus) and Arabidopsis thaliana. These plants were exposed in hydroponics to a panel of well-characterized TiO 2 -NPs, with diameters ranging from 12 to 140 nm, either anatase or rutile. Their accumulation in plant tissues is currently being assessed by complementary imaging techniques: scanning electron microscopy (SEM), transmission electron microscopy (TEM), micro-X-ray fluorescence (SR-μ-XRF) imaging and micro-particle induced X-ray emission (μ-PIXE) imaging. Moreover, the impact of TiO 2 -NP exposure on germination rate, root elongation, dry biomass and evapotranspiration is evaluated. Preliminary results are presented here, with data collected on wheat plants exposed to 12 nm and 25 nm anatase TiO 2 -NPs. These results show that TiO 2 -NPs are taken up by plants, and do not significantly alter their germination and root elongation. These results underline the necessity of deeper evaluation of nanoparticle ecotoxicity, and particularly on their interaction with plants.

  18. Comparative proteomic analysis of the molecular responses of mouse macrophages to titanium dioxide and copper oxide nanoparticles unravels some toxic mechanisms for copper oxide nanoparticles in macrophages.

    Directory of Open Access Journals (Sweden)

    Sarah Triboulet

    Full Text Available Titanium dioxide and copper oxide nanoparticles are more and more widely used because of their catalytic properties, of their light absorbing properties (titanium dioxide or of their biocidal properties (copper oxide, increasing the risk of adverse health effects. In this frame, the responses of mouse macrophages were studied. Both proteomic and targeted analyses were performed to investigate several parameters, such as phagocytic capacity, cytokine release, copper release, and response at sub toxic doses. Besides titanium dioxide and copper oxide nanoparticles, copper ions were used as controls. We also showed that the overall copper release in the cell does not explain per se the toxicity observed with copper oxide nanoparticles. In addition, both copper ion and copper oxide nanoparticles, but not titanium oxide, induced DNA strands breaks in macrophages. As to functional responses, the phagocytic capacity was not hampered by any of the treatments at non-toxic doses, while copper ion decreased the lipopolysaccharide-induced cytokine and nitric oxide productions. The proteomic analyses highlighted very few changes induced by titanium dioxide nanoparticles, but an induction of heme oxygenase, an increase of glutathione synthesis and a decrease of tetrahydrobiopterin in response to copper oxide nanoparticles. Subsequent targeted analyses demonstrated that the increase in glutathione biosynthesis and the induction of heme oxygenase (e.g. by lovastatin/monacolin K are critical for macrophages to survive a copper challenge, and that the intermediates of the catecholamine pathway induce a strong cross toxicity with copper oxide nanoparticles and copper ions.

  19. Comparative proteomic analysis of the molecular responses of mouse macrophages to titanium dioxide and copper oxide nanoparticles unravels some toxic mechanisms for copper oxide nanoparticles in macrophages.

    Science.gov (United States)

    Triboulet, Sarah; Aude-Garcia, Catherine; Armand, Lucie; Collin-Faure, Véronique; Chevallet, Mireille; Diemer, Hélène; Gerdil, Adèle; Proamer, Fabienne; Strub, Jean-Marc; Habert, Aurélie; Herlin, Nathalie; Van Dorsselaer, Alain; Carrière, Marie; Rabilloud, Thierry

    2015-01-01

    Titanium dioxide and copper oxide nanoparticles are more and more widely used because of their catalytic properties, of their light absorbing properties (titanium dioxide) or of their biocidal properties (copper oxide), increasing the risk of adverse health effects. In this frame, the responses of mouse macrophages were studied. Both proteomic and targeted analyses were performed to investigate several parameters, such as phagocytic capacity, cytokine release, copper release, and response at sub toxic doses. Besides titanium dioxide and copper oxide nanoparticles, copper ions were used as controls. We also showed that the overall copper release in the cell does not explain per se the toxicity observed with copper oxide nanoparticles. In addition, both copper ion and copper oxide nanoparticles, but not titanium oxide, induced DNA strands breaks in macrophages. As to functional responses, the phagocytic capacity was not hampered by any of the treatments at non-toxic doses, while copper ion decreased the lipopolysaccharide-induced cytokine and nitric oxide productions. The proteomic analyses highlighted very few changes induced by titanium dioxide nanoparticles, but an induction of heme oxygenase, an increase of glutathione synthesis and a decrease of tetrahydrobiopterin in response to copper oxide nanoparticles. Subsequent targeted analyses demonstrated that the increase in glutathione biosynthesis and the induction of heme oxygenase (e.g. by lovastatin/monacolin K) are critical for macrophages to survive a copper challenge, and that the intermediates of the catecholamine pathway induce a strong cross toxicity with copper oxide nanoparticles and copper ions.

  20. Characterization of biodegradable polycaprolactone containing titanium dioxide micro and nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Govorčin Bajsić, E.; Ocelić Bulatović, V.; Šlouf, Miroslav; Šitum, Ana

    2014-01-01

    Roč. 8, č. 7 (2014), s. 536-540 ISSN 2010-376X R&D Projects: GA TA ČR TE01020118 Institutional support: RVO:61389013 Keywords : morphology * polycaprolactone * thermal properties Subject RIV: EA - Cell Biology http://waset.org/Publication/characterization-of-biodegradable-polycaprolactone-containing-titanium-dioxide-micro-and-nanoparticles/9998694

  1. Maternal exposure to titanium dioxide nanoparticles during pregnancy and lactation alters offspring hippocampal mRNA BAX and Bcl-2 levels, induces apoptosis and decreases neurogenesis.

    Science.gov (United States)

    Ebrahimzadeh Bideskan, Alireza; Mohammadipour, Abbas; Fazel, Alireza; Haghir, Hossein; Rafatpanah, Houshang; Hosseini, Mahmoud; Rajabzadeh, Aliakbar

    2017-07-05

    The usage of Titanium dioxide nanoparticles (TiO 2 -NPs) covers a vast area in different fields ranging from cosmetics and food to the production of drugs. Maternal exposure to TiO 2 -NPs during developmental period has been associated with hippocampal injury and with a decrease in learning and memory status of the offspring. However, little is known about its injury mechanism. This paper describes the in vivo neurotoxic effects of TiO 2 -NPs on rat offspring hippocampus during developmental period. Pregnant and lactating Wistar rats received intragastric TiO 2 -NPs (100mg/kg body weight) daily from gestational day (GD) 2 to (GD) 21 and postnatal day (PD) 2 to (PD) 21 respectively. Animals in the control groups received an equal volume of distilled water via gavage. At the end of the treatment process, offspring were deeply anesthetized and sacrificed. Then brains of each group were collected and sections of the rat offspring's brains were stained using TUNEL staining (for detection of apoptotic cells) and immunostaining (for neurogenesis). Moreover, the right hippocampus (n=6 per each group) were removed from the right hemisphere for evaluating the expression of Bax and Bcl-2 level. Results of histopatological examination by TUNEL staining showed that maternal exposure to TiO 2 -NPs during pregnancy and lactation periods increased apoptotic cells significantly (P<0.01) in the offspring hippocampus. The immunolabeling of double cortin (DCX) protein as neurogenesis marker also showed that TiO 2 -NPs reduced neurogenesis in the hippocampus of the offspring (P<0.05). Moreover, in comparison with the control group, the mRNA levels of Bax and Bcl-2 in the TiO 2 -NPs group significantly increased and decreased, respectively (P<0.01). These findings provide strong evidence that maternal exposure to TiO 2 -NPs significantly impact hippocampal neurogenesis and apoptosis in the offspring. The potential impact of nanoparticle exposure for millions of pregnant mothers and

  2. The stress caused by nitrite with titanium dioxide nanoparticles under UVA irradiation in human keratinocyte cell

    International Nuclear Information System (INIS)

    Tu, Min; Huang, Yi; Li, Hai-Ling; Gao, Zhong-Hong

    2012-01-01

    Highlights: ► Nitrite increased photo-toxicity of nano-TiO 2 on human keratinocyte cells in a dose-dependant manner. ► Morphological study suggested the cell death may be mediated by apoptosis inducing factor. ► Protein nitration was generated in the cells, and the most abundant nitrated protein was identified as cystatin-A. ► Tyr35 was the most likely site to be nitrated in cystatin-A. -- Abstract: Our previous work found that in the presence of nitrite, titanium dioxide nanoparticles can cause protein tyrosine nitration under UVA irradiation in vivo. In this paper, the human keratinocyte cells was used as a skin cell model to further study the photo-toxicity of titanium dioxide nanoparticles when nitrite was present. The results showed that nitrite increased the photo-toxicity of titanium dioxide in a dose-dependant manner, and generated protein tyrosine nitration in keratinocyte cells. Morphological study of keratinocyte cells suggested a specific apoptosis mediated by apoptosis inducing factor. It was also found the main target nitrated in cells was cystatin-A, which expressed abundantly in cytoplasm and functioned as a cysteine protease inhibitor. The stress induced by titanium dioxide with nitrite under UVA irradiation in human keratinocyte cells appeared to trigger the apoptosis inducing factor mediated cell death and lose the inhibition of active caspase by cystatin-A. We conclude that nitrite can bring new damage and stress to human keratinocyte cells with titanium dioxide nanoparticles under UVA irradiation.

  3. Fate of cerium dioxide nanoparticles in endothelial cells: exocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, Claudia, E-mail: Claudia.Strobel@med.uni-jena.de [Jena University Hospital – Friedrich Schiller University Jena, Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology (Germany); Oehring, Hartmut [Jena University Hospital – Friedrich Schiller University Jena, Institute of Anatomy II (Germany); Herrmann, Rudolf [University of Augsburg, Department of Physics (Germany); Förster, Martin [Jena University Hospital – Friedrich Schiller University Jena, Department of Internal Medicine I, Division of Pulmonary Medicine and Allergy/Immunology (Germany); Reller, Armin [University of Augsburg, Department of Physics (Germany); Hilger, Ingrid, E-mail: ingrid.hilger@med.uni-jena.de [Jena University Hospital – Friedrich Schiller University Jena, Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology (Germany)

    2015-05-15

    Although cytotoxicity and endocytosis of nanoparticles have been the subject of numerous studies, investigations regarding exocytosis as an important mechanism to reduce intracellular nanoparticle accumulation are rather rare and there is a distinct lack of knowledge. The current study investigated the behavior of human microvascular endothelial cells to exocytose cerium dioxide (CeO{sub 2}) nanoparticles (18.8 nm) by utilization of specific inhibitors [brefeldin A; nocodazole; methyl-β-cyclodextrin (MβcD)] and different analytical methods (flow cytometry, transmission electron microscopy, inductively coupled plasma mass spectrometry). Overall, it was found that endothelial cells were able to release CeO{sub 2} nanoparticles via exocytosis after the migration of nanoparticle containing endosomes toward the plasma membrane. The exocytosis process occurred mainly by fusion of vesicular membranes with plasma membrane resulting in the discharge of vesicular content to extracellular environment. Nevertheless, it seems to be likely that nanoparticles present in the cytosol could leave the cells in a direct manner. MβcD treatment led to the strongest inhibition of the nanoparticle exocytosis indicating a significant role of the plasma membrane cholesterol content in the exocytosis process. Brefeldin A (inhibitor of Golgi-to-cell-surface-transport) caused a higher inhibitory effect on exocytosis than nocodazole (inhibitor of microtubules). Thus, the transfer from distal Golgi compartments to the cell surface influenced the exocytosis process of the CeO{sub 2} nanoparticles more than the microtubule-associated transport. In conclusion, endothelial cells, which came in contact with nanoparticles, e.g., after intravenously applied nano-based drugs, can regulate their intracellular nanoparticle amount, which is necessary to avoid adverse nanoparticle effects on cells.

  4. Mitochondrial dysfunction and loss of glutamate uptake in primary astrocytes exposed to titanium dioxide nanoparticles

    Science.gov (United States)

    Wilson, Christina L.; Natarajan, Vaishaali; Hayward, Stephen L.; Khalimonchuk, Oleh; Kidambi, Srivatsan

    2015-11-01

    Titanium dioxide (TiO2) nanoparticles are currently the second most produced engineered nanomaterial in the world with vast usage in consumer products leading to recurrent human exposure. Animal studies indicate significant nanoparticle accumulation in the brain while cellular toxicity studies demonstrate negative effects on neuronal cell viability and function. However, the toxicological effects of nanoparticles on astrocytes, the most abundant cells in the brain, have not been extensively investigated. Therefore, we determined the sub-toxic effect of three different TiO2 nanoparticles (rutile, anatase and commercially available P25 TiO2 nanoparticles) on primary rat cortical astrocytes. We evaluated some events related to astrocyte functions and mitochondrial dysregulation: (1) glutamate uptake; (2) redox signaling mechanisms by measuring ROS production; (3) the expression patterns of dynamin-related proteins (DRPs) and mitofusins 1 and 2, whose expression is central to mitochondrial dynamics; and (4) mitochondrial morphology by MitoTracker® Red CMXRos staining. Anatase, rutile and P25 were found to have LC50 values of 88.22 +/- 10.56 ppm, 136.0 +/- 31.73 ppm and 62.37 +/- 9.06 ppm respectively indicating nanoparticle specific toxicity. All three TiO2 nanoparticles induced a significant loss in glutamate uptake indicative of a loss in vital astrocyte function. TiO2 nanoparticles also induced an increase in reactive oxygen species generation, and a decrease in mitochondrial membrane potential, suggesting mitochondrial damage. TiO2 nanoparticle exposure altered expression patterns of DRPs at low concentrations (25 ppm) and apoptotic fission at high concentrations (100 ppm). TiO2 nanoparticle exposure also resulted in changes to mitochondrial morphology confirmed by mitochondrial staining. Collectively, our data provide compelling evidence that TiO2 nanoparticle exposure has potential implications in astrocyte-mediated neurological dysfunction.Titanium dioxide (Ti

  5. Cytotoxicity of titanium dioxide nanoparticles in mouse fibroblast cells.

    Science.gov (United States)

    Jin, Cheng-Yu; Zhu, Bang-Shang; Wang, Xue-Feng; Lu, Qing-Hua

    2008-09-01

    Nanotitanium dioxide (TiO2) is an important industrial material that is widely used as an additive in cosmetics, pharmaceuticals, and food colorants. Although the small size of the TiO2 nanoparticle is useful in various applications, the biosafety of this material needs to be evaluated. In this study, mouse fibroblast (L929) cells were used to evaluate the cytotoxicity of different concentrations (3-600 microg/mL) of homogeneous and weakly aggregated TiO2 nanoparticles in aqueous solution. The L929 cells became round and even shrank as the concentration of TiO2 nanoparticles increased. Moreover, TiO2 nanoparticle-treated cells had condensed fragmented chromatin or were directly necrosed, as observed by acridine orange (AO) staining. The transmission electron microscopy (TEM) analysis showed that in cells cultured in a medium containing 300 microg/mL TiO2, the number of lysosomes increased, and some cytoplasmic organelles were damaged. In addition, there was a significant increase in oxidative stress at higher TiO2 nanoparticle concentrations (>60 microg/mL). As the concentration of TiO2 nanoparticles increased in the culture medium, the levels of reactive oxygen species (ROS) and lactate dehydrogenase (LDH) increased, while those of methyl tetrazolium cytotoxicity (MTT), glutathione (GSH), and superoxide dismutase (SOD) decreased. A possible mechanism for the cytotoxicity of TiO2 nanoparticles is also discussed.

  6. Acute Toxicity of Intravenously Administered Titanium Dioxide Nanoparticles in Mice

    OpenAIRE

    Xu, Jiaying; Shi, Hongbo; Ruth, Magaye; Yu, Hongsheng; Lazar, Lissy; Zou, Baobo; Yang, Cui; Wu, Aiguo; Zhao, Jinshun

    2013-01-01

    BACKGROUND: With a wide range of applications, titanium dioxide (TiO₂) nanoparticles (NPs) are manufactured worldwide in large quantities. Recently, in the field of nanomedicine, intravenous injection of TiO₂ nanoparticulate carriers directly into the bloodstream has raised public concerns on their toxicity to humans. METHODS: In this study, mice were injected intravenously with a single dose of TiO₂ NPs at varying dose levels (0, 140, 300, 645, or 1387 mg/kg). Animal mortality, blood biochem...

  7. Molecular and physiological responses to titanium dioxide and cerium oxide nanoparticles in Arabidopsis

    Science.gov (United States)

    - Changes in tissue transcriptomes and productivity of Arabidopsis thaliana were investigated during exposure of plants to two widely-used engineered metal oxide nanoparticles, titanium dioxide (nano-titanium) and cerium dioxide (nano-cerium). Microarray analyses confirmed that e...

  8. A review on potential neurotoxicity of titanium dioxide nanoparticles

    Science.gov (United States)

    Song, Bin; Liu, Jia; Feng, Xiaoli; Wei, Limin; Shao, Longquan

    2015-08-01

    As the rapid development of nanotechnology in the past three decades, titanium dioxide nanoparticles (TiO2 NPs), for their peculiar physicochemical properties, are widely applied in consumer products, food additives, cosmetics, drug carriers, and so on. However, little is known about their potential exposure and neurotoxic effects. Once NPs are unintentionally exposed to human beings, they could be absorbed, and then accumulated in the brain regions by passing through the blood-brain barrier (BBB) or through the nose-to-brain pathway, potentially leading to dysfunctions of central nerve system (CNS). Besides, NPs may affect the brain development of embryo by crossing the placental barrier. A few in vivo and in vitro researches have demonstrated that the morphology and function of neuronal or glial cells could be impaired by TiO2 NPs which might induce cell necrosis. Cellular components, such as mitochondrial, lysosome, and cytoskeleton, could also be influenced as well. The recognition ability, spatial memory, and learning ability of TiO2 NPs-treated rodents were significantly impaired, which meant that accumulation of TiO2 NPs in the brain could lead to neurodegeneration. However, conclusions obtained from those studies were not consistent with each other as researchers may choose different experimental parameters, including administration ways, dosage, size, and crystal structure of TiO2 NPs. Therefore, in order to fully understand the potential risks of TiO2 NPs to brain health, figure out research areas where further studies are required, and improve its bio-safety for applications in the near future, how TiO2 NPs interact with the brain is investigated in this review by summarizing the current researches on neurotoxicity induced by TiO2 NPs.

  9. Titanium dioxide nanoparticles induce human eosinophil adhesion onto endothelial EA.hy926 cells via activation of phosphoinositide 3-kinase/Akt cell signalling pathway.

    Science.gov (United States)

    Murphy-Marion, Maxime; Girard, Denis

    2018-02-01

    The use of nanoparticles (NPs) for developing new therapeutic strategies in a variety of diseases is gaining increasing attention. However, NPs could possess undesired effects, including pro-inflammatory activities. Despite the fact that several studies reported that NPs may induce or exacerbate eosinophilic inflammation in vivo in rodents, the information regarding the direct interaction between NPs and human eosinophils is lacking. In the present study, we test the possibility that NPs could alter the capacity of human eosinophils to adhere onto a cellular substratum. Using a panel of NPs, we found that several were able to increase the adhesion of human eosinophil onto endothelial EA.hy926 cells. Among them, TiO 2 NPs were the most potent and we therefore pursue this study with these NPs. TiO 2 NPs were found to increase the adhesion of eosinophils in a concentration dependent fashion. TiO 2 NPs did not alter the cell surface expression of a panel of cellular adhesion molecules, but CD29. Indeed, a weak to moderate, but significant, decrease of CD29 was observed after 30min but returned to normal levels after 90min. TiO 2 NPs were found to activate Akt, one important target of phosphoinositide 3-kinase (PI3K). However, despite the fact that cells were fully responsive to the cytokine GM-CSF activating both Akt and Erk-1/2, TiO 2 NPs did not activate Erk-1/2. Using a pharmacological approach with the PI3K/Akt inhibitor, wortmannin, the ability of TiO 2 NPs to activate Akt was drastically inhibited and, further, their capacity to increase adhesion of eosinophils was reversed. This study provides insights into the effects of NPs on the biology of human eosinophils indicating that as other agents, NPs, namely TiO 2 NPs, can induce intracellular events associated with a cellular function, adhesion. Copyright © 2017 Elsevier GmbH. All rights reserved.

  10. Titanium dioxide nanoparticles: a review of current toxicological data

    Science.gov (United States)

    2013-01-01

    Titanium dioxide (TiO2) nanoparticles (NPs) are manufactured worldwide in large quantities for use in a wide range of applications. TiO2 NPs possess different physicochemical properties compared to their fine particle (FP) analogs, which might alter their bioactivity. Most of the literature cited here has focused on the respiratory system, showing the importance of inhalation as the primary route for TiO2 NP exposure in the workplace. TiO2 NPs may translocate to systemic organs from the lung and gastrointestinal tract (GIT) although the rate of translocation appears low. There have also been studies focusing on other potential routes of human exposure. Oral exposure mainly occurs through food products containing TiO2 NP-additives. Most dermal exposure studies, whether in vivo or in vitro, report that TiO2 NPs do not penetrate the stratum corneum (SC). In the field of nanomedicine, intravenous injection can deliver TiO2 nanoparticulate carriers directly into the human body. Upon intravenous exposure, TiO2 NPs can induce pathological lesions of the liver, spleen, kidneys, and brain. We have also shown here that most of these effects may be due to the use of very high doses of TiO2 NPs. There is also an enormous lack of epidemiological data regarding TiO2 NPs in spite of its increased production and use. However, long-term inhalation studies in rats have reported lung tumors. This review summarizes the current knowledge on the toxicology of TiO2 NPs and points out areas where further information is needed. PMID:23587290

  11. Titanium dioxide nanoparticles: a review of current toxicological data.

    Science.gov (United States)

    Shi, Hongbo; Magaye, Ruth; Castranova, Vincent; Zhao, Jinshun

    2013-04-15

    Titanium dioxide (TiO2) nanoparticles (NPs) are manufactured worldwide in large quantities for use in a wide range of applications. TiO2 NPs possess different physicochemical properties compared to their fine particle (FP) analogs, which might alter their bioactivity. Most of the literature cited here has focused on the respiratory system, showing the importance of inhalation as the primary route for TiO2 NP exposure in the workplace. TiO2 NPs may translocate to systemic organs from the lung and gastrointestinal tract (GIT) although the rate of translocation appears low. There have also been studies focusing on other potential routes of human exposure. Oral exposure mainly occurs through food products containing TiO2 NP-additives. Most dermal exposure studies, whether in vivo or in vitro, report that TiO2 NPs do not penetrate the stratum corneum (SC). In the field of nanomedicine, intravenous injection can deliver TiO2 nanoparticulate carriers directly into the human body. Upon intravenous exposure, TiO2 NPs can induce pathological lesions of the liver, spleen, kidneys, and brain. We have also shown here that most of these effects may be due to the use of very high doses of TiO2 NPs. There is also an enormous lack of epidemiological data regarding TiO2 NPs in spite of its increased production and use. However, long-term inhalation studies in rats have reported lung tumors. This review summarizes the current knowledge on the toxicology of TiO2 NPs and points out areas where further information is needed.

  12. Acute toxicity of intravenously administered titanium dioxide nanoparticles in mice.

    Directory of Open Access Journals (Sweden)

    Jiaying Xu

    Full Text Available BACKGROUND: With a wide range of applications, titanium dioxide (TiO₂ nanoparticles (NPs are manufactured worldwide in large quantities. Recently, in the field of nanomedicine, intravenous injection of TiO₂ nanoparticulate carriers directly into the bloodstream has raised public concerns on their toxicity to humans. METHODS: In this study, mice were injected intravenously with a single dose of TiO₂ NPs at varying dose levels (0, 140, 300, 645, or 1387 mg/kg. Animal mortality, blood biochemistry, hematology, genotoxicity and histopathology were investigated 14 days after treatment. RESULTS: Death of mice in the highest dose (1387 mg/kg group was observed at day two after TiO₂ NPs injection. At day 7, acute toxicity symptoms, such as decreased physical activity and decreased intake of food and water, were observed in the highest dose group. Hematological analysis and the micronucleus test showed no significant acute hematological or genetic toxicity except an increase in the white blood cell (WBC count among mice 645 mg/kg dose group. However, the spleen of the mice showed significantly higher tissue weight/body weight (BW coefficients, and lower liver and kidney coefficients in the TiO₂ NPs treated mice compared to control. The biochemical parameters and histological tissue sections indicated that TiO₂ NPs treatment could induce different degrees of damage in the brain, lung, spleen, liver and kidneys. However, no pathological effects were observed in the heart in TiO₂ NPs treated mice. CONCLUSIONS: Intravenous injection of TiO₂ NPs at high doses in mice could cause acute toxicity effects in the brain, lung, spleen, liver, and kidney. No significant hematological or genetic toxicity was observed.

  13. Effects of titanium dioxide nanoparticles derived from ...

    Science.gov (United States)

    Increased manufacture of TiO2 nano-products has caused concern about the potential toxicity of these products to the environment and in public health. Identification and confirmation of the presence of TiO2 nanoparticles derived from consumer products as opposed to industrial TiO2 NPs warrants examination in exploring the significance of their release and resultant impacts on the environment. To this end we examined the significance of the release of these particles and their toxic effect on the marine diatom algae Thalassiosira pseudonana. Our results indicate that nano-TiO2 sunscreen and toothpaste exhibit more toxicity in comparison to industrial TiO2, and inhibited the growth of the marine diatom Thalassiosira pseudonana. This inhibition was proportional to the exposure time and concentrations of nano-TiO2. Our findings indicate a significant effect, and therefore further research is warranted in evaluation and assessment of the toxicity of modified nano-TiO2 derived from consumer products and their physicochemical properties. Submit to journal Environmental Science and Pollution Research.

  14. Hydroxyl radicals ({center_dot}OH) are associated with titanium dioxide (TiO{sub 2}) nanoparticle-induced cytotoxicity and oxidative DNA damage in fish cells

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, James F.; Davies, Simon J.; Dodd, Nicholas J.F. [School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Jha, Awadhesh N. [School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: a.jha@plymouth.ac.uk

    2008-04-02

    TiO{sub 2} nanoparticles (<100 nm diameter) have been reported to cause oxidative stress related effects, including inflammation, cytotoxicity and genomic instability, either alone or in the presence of UVA irradiation in mammalian studies. Despite the fact that the aquatic environment is often the ultimate recipient of all contaminants there is a paucity of data pertaining to the potential detrimental effects of nanoparticles on aquatic organisms. Therefore, these investigations aimed to evaluate the potential cytotoxic and genotoxic effects of TiO{sub 2} nanoparticles on goldfish skin cells (GFSk-S1), either alone or in combination with UVA. Whilst neutral red retention (NRR) assay (a measure of lysosomal membrane integrity) was used to evaluate cell viability, a modified Comet assay using bacterial lesion-specific repair endonucleases (Endo-III, Fpg) was employed to specifically target oxidative DNA damage. Additionally, electron spin resonance (ESR) studies with different spin traps were carried out for qualitative analysis of free radical generation. For cell viability, TiO{sub 2} alone (0.1-1000 {mu}g ml{sup -1}) had little effect whereas co-exposure with UVA (0.5-2.0 kJ m{sup -2}) caused a significant dose-dependent decrease which was dependent on both the concentration of TiO{sub 2} and the dose of UVA administered. For the Comet assay, doses of 1, 10 and 100 {mu}g ml{sup -1} in the absence of UVA caused elevated levels of Fpg-sensitive sites, indicating the oxidation of purine DNA bases (i.e. guanine) by TiO{sub 2}. UVA irradiation of TiO{sub 2}-treated cells caused further increases in DNA damage. ESR studies revealed that the observed toxic effects of nanoparticulate TiO{sub 2} were most likely due to hydroxyl radical ({center_dot}OH) formation.

  15. Carbon materials-functionalized tin dioxide nanoparticles toward robust, high-performance nitrogen dioxide gas sensor.

    Science.gov (United States)

    Zhang, Rui; Liu, Xiupeng; Zhou, Tingting; Wang, Lili; Zhang, Tong

    2018-08-15

    Carbon (C) materials, which process excellent electrical conductivity and high carrier mobility, are promising sensing materials as active units for gas sensors. However, structural agglomeration caused by chemical processes results in a small resistance change and low sensing response. To address the above issues, structure-derived carbon-coated tin dioxide (SnO 2 ) nanoparticles having distinct core-shell morphology with a 3D net-like structure and highly uniform size are prepared by careful synthesis and fine structural design. The optimum carbon-coated SnO 2 nanoparticles (SnO 2 /C)-based gas sensor exhibits a low working temperature, excellent selectivity and fast response-recovery properties. In addition, the SnO 2 /C-based gas sensor can maintain a sensitivity to nitrogen dioxide (NO 2 ) of 3 after being cycled 4 times at 140 °C for, suggesting its good long-term stability. The structural integrity, good synergistic properties, and high gas-sensing performance of SnO 2 /C render it a promising sensing material for advanced gas sensors. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Titanium Dioxide Nanoparticles Trigger Loss of Function and Perturbation of Mitochondrial Dynamics in Primary Hepatocytes.

    Directory of Open Access Journals (Sweden)

    Vaishaali Natarajan

    Full Text Available Titanium dioxide (TiO2 nanoparticles are one of the most highly manufactured and employed nanomaterials in the world with applications in copious industrial and consumer products. The liver is a major accumulation site for many nanoparticles, including TiO2, directly through intentional exposure or indirectly through unintentional ingestion via water, food or animals and increased environmental contamination. Growing concerns over the current usage of TiO2 coupled with the lack of mechanistic understanding of its potential health risk is the motivation for this study. Here we determined the toxic effect of three different TiO2 nanoparticles (commercially available rutile, anatase and P25 on primary rat hepatocytes. Specifically, we evaluated events related to hepatocyte functions and mitochondrial dynamics: (1 urea and albumin synthesis using colorimetric and ELISA assays, respectively; (2 redox signaling mechanisms by measuring reactive oxygen species (ROS production, manganese superoxide dismutase (MnSOD activity and mitochondrial membrane potential (MMP; (3 OPA1 and Mfn-1 expression that mediates the mitochondrial dynamics by PCR; and (4 mitochondrial morphology by MitoTracker Green FM staining. All three TiO2 nanoparticles induced a significant loss (p < 0.05 in hepatocyte functions even at concentrations as low as 50 ppm with commercially used P25 causing maximum damage. TiO2 nanoparticles induced a strong oxidative stress in primary hepatocytes. TiO2 nanoparticles exposure also resulted in morphological changes in mitochondria and substantial loss in the fusion process, thus impairing the mitochondrial dynamics. Although this study demonstrated that TiO2 nanoparticles exposure resulted in substantial damage to primary hepatocytes, more in vitro and in vivo studies are required to determine the complete toxicological mechanism in primary hepatocytes and subsequently liver function.

  17. Hydroxyl radicals (·OH) are associated with titanium dioxide (TiO2) nanoparticle-induced cytotoxicity and oxidative DNA damage in fish cells

    International Nuclear Information System (INIS)

    Reeves, James F.; Davies, Simon J.; Dodd, Nicholas J.F.; Jha, Awadhesh N.

    2008-01-01

    TiO 2 nanoparticles ( 2 nanoparticles on goldfish skin cells (GFSk-S1), either alone or in combination with UVA. Whilst neutral red retention (NRR) assay (a measure of lysosomal membrane integrity) was used to evaluate cell viability, a modified Comet assay using bacterial lesion-specific repair endonucleases (Endo-III, Fpg) was employed to specifically target oxidative DNA damage. Additionally, electron spin resonance (ESR) studies with different spin traps were carried out for qualitative analysis of free radical generation. For cell viability, TiO 2 alone (0.1-1000 μg ml -1 ) had little effect whereas co-exposure with UVA (0.5-2.0 kJ m -2 ) caused a significant dose-dependent decrease which was dependent on both the concentration of TiO 2 and the dose of UVA administered. For the Comet assay, doses of 1, 10 and 100 μg ml -1 in the absence of UVA caused elevated levels of Fpg-sensitive sites, indicating the oxidation of purine DNA bases (i.e. guanine) by TiO 2 . UVA irradiation of TiO 2 -treated cells caused further increases in DNA damage. ESR studies revealed that the observed toxic effects of nanoparticulate TiO 2 were most likely due to hydroxyl radical (·OH) formation

  18. Research Progress about the Relationship between Nanoparticles Silicon Dioxide and Lung Cancer

    Directory of Open Access Journals (Sweden)

    Chun DAI

    2014-10-01

    Full Text Available Nano-silicon dioxide widely distributed in plastic, rubber, ceramics, paint, adhesives, and many other fields, and it is the product of coal combustion. A growing evidence shows that nano-silicon dioxide has certain correlation with respiratory system disease. In this paper, we synthesized existing researches of domestic and abroad, summarized the lung toxicity of nanoparticles. This article are reviewed from the physical and chemical properties of nanoparticles silicon dioxide, exposure conditions and environment, and the pathogenic mechanism of nano-silicon dioxide.

  19. Anti-pepsin activity of silicon dioxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Hussein Kadhem Al-Hakeim

    2016-09-01

    Full Text Available SiO2NPs as an inhibitor of pepsin enzyme for treatment of gastro-esophageal reflux disease (GERD was used. Silicon dioxide nanoparticles (pepsin coated SiO2NPs are among the safest nanoparticles that can be used inside the human body. The activity of pepsin before and after the addition of certain amounts of the NPs to the reaction mixture was measured spectrophotometrically. Furthermore, these experiments were repeated at different temperatures, different weights of NPs, and different ionic strengths. The kinetic aparameters (Km & Vmax of the pepsin catalyzed reactions were calculated from the Lineweaver-Burke plots. The results showed that there is a significant reduction of pepsin activity by SiO2NPs (Vmax of free pepsin = 4.82 U and Vmax of the immobilizedpepsin = 2.90 U. The results also indicated that the presence of ionic strength causes remarkable reduction of pepsin activity. It can be concluded the best condition for inhibition of pepsin activity is by using a combination of SiO2NPs and high concentration NaCl at 37 °C.

  20. Pulmonary toxicity of well-dispersed titanium dioxide nanoparticles following intratracheal instillation

    International Nuclear Information System (INIS)

    Yoshiura, Yukiko; Izumi, Hiroto; Oyabu, Takako; Hashiba, Masayoshi; Kambara, Tatsunori; Mizuguchi, Yohei; Lee, Byeong Woo; Okada, Takami; Tomonaga, Taisuke; Myojo, Toshihiko; Yamamoto, Kazuhiro; Kitajima, Shinichi; Horie, Masanori; Kuroda, Etsushi; Morimoto, Yasuo

    2015-01-01

    In order to investigate the pulmonary toxicity of titanium dioxide (TiO 2 ) nanoparticles, we performed an intratracheal instillation study with rats of well-dispersed TiO 2 nanoparticles and examined the pulmonary inflammation and histopathological changes in the lung. Wistar Hannover rats were intratracheally administered 0.2 mg (0.66 mg/kg) and 1.0 mg (3.3 mg/kg) of well-dispersed TiO 2 nanoparticles (P90; diameter of agglomerates: 25 nm), then the pulmonary inflammation responses were examined from 3 days to 6 months after the instillation, and the pathological features were examined up to 24 months. Transient inflammation and the upregulation of chemokines in the broncho-alveolar lavage fluid were observed for 1 month. No respiratory tumors or severe fibrosis were observed during the recovery time. These data suggest that transient inflammation induced by TiO 2 may not lead to chronic, irreversible legions in the lung, and that TiO 2 nanoparticles may not have a high potential for lung disorder

  1. Pulmonary toxicity of well-dispersed titanium dioxide nanoparticles following intratracheal instillation

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiura, Yukiko, E-mail: y-yoshiura@med.uoeh-u.ac.jp; Izumi, Hiroto [University of Occupational and Environmental Health, Department of Occupational Pneumology, Institute of Industrial Ecological Science (Japan); Oyabu, Takako [University of Occupational and Environmental Health, Department of Environmental Health Engineering, Institute of Industrial Ecological Sciences (Japan); Hashiba, Masayoshi; Kambara, Tatsunori [University of Occupational and Environmental Health, Department of Occupational Pneumology, Institute of Industrial Ecological Science (Japan); Mizuguchi, Yohei; Lee, Byeong Woo; Okada, Takami [University of Occupational and Environmental Health, Department of Environmental Health Engineering, Institute of Industrial Ecological Sciences (Japan); Tomonaga, Taisuke [University of Occupational and Environmental Health, Department of Occupational Pneumology, Institute of Industrial Ecological Science (Japan); Myojo, Toshihiko [University of Occupational and Environmental Health, Department of Environmental Health Engineering, Institute of Industrial Ecological Sciences (Japan); Yamamoto, Kazuhiro [National Institute of Advanced Industrial Science and Technology (AIST) (Japan); Kitajima, Shinichi [National Sanatorium Hoshizuka Keiaien (Japan); Horie, Masanori [National Institute of Advanced Industrial Science and Technology (AIST), Health Research Institute (HRI) (Japan); Kuroda, Etsushi [Osaka University, Laboratory of Vaccine Science, WPI Immunology Frontier Research Center (Japan); Morimoto, Yasuo [University of Occupational and Environmental Health, Department of Occupational Pneumology, Institute of Industrial Ecological Science (Japan)

    2015-06-15

    In order to investigate the pulmonary toxicity of titanium dioxide (TiO{sub 2}) nanoparticles, we performed an intratracheal instillation study with rats of well-dispersed TiO{sub 2} nanoparticles and examined the pulmonary inflammation and histopathological changes in the lung. Wistar Hannover rats were intratracheally administered 0.2 mg (0.66 mg/kg) and 1.0 mg (3.3 mg/kg) of well-dispersed TiO{sub 2} nanoparticles (P90; diameter of agglomerates: 25 nm), then the pulmonary inflammation responses were examined from 3 days to 6 months after the instillation, and the pathological features were examined up to 24 months. Transient inflammation and the upregulation of chemokines in the broncho-alveolar lavage fluid were observed for 1 month. No respiratory tumors or severe fibrosis were observed during the recovery time. These data suggest that transient inflammation induced by TiO{sub 2} may not lead to chronic, irreversible legions in the lung, and that TiO{sub 2} nanoparticles may not have a high potential for lung disorder.

  2. Interaction of titanium dioxide nanoparticles with glucose on young rats after oral administration.

    Science.gov (United States)

    Chen, Zhangjian; Wang, Yun; Zhuo, Lin; Chen, Shi; Zhao, Lin; Chen, Tian; Li, Yang; Zhang, Wenxiao; Gao, Xin; Li, Ping; Wang, Haifang; Jia, Guang

    2015-10-01

    Titanium dioxide nanoparticles (TiO2 NPs) have a broad application prospect in replace with TiO2 used as a food additive, especially used in sweets. Understanding the interaction of TiO2 NPs with sugar is meaningful for health promotion. We used a young animal model to study the toxicological effect of orally administrated TiO2 NPs at doses of 0, 2, 10 and 50 mg/kg per day with or without daily consumption of 1.8 g/kg glucose for 30 days and 90 days. The results showed that oral exposure to TiO2 NPs and TiO2 NPs+glucose both induced liver, kidney, and heart injuries as well as changes in the count of white and red blood cells in a dose, time and gender-dependent manner. The toxicological interactions between orally-administrated TiO2 NPs and glucose were evident, but differed among target organs. These results suggest that it is necessary to limit dietary co-exposure to TiO2 NPs and sugar. Nanotechnology has gained entrance in the food industry, with the presence of nanoparticles now in many food items. Despite this increasing trend, the potential toxic effects of these nanoparticles to human remain unknown. In this article, the authors studied titanium dioxide nanoparticles (TiO2 NPs), which are commonly used as food additive, together with glucose. The findings of possible adverse effects on liver, kidney, and heart might point to a rethink of using glucose and TiO2 NPs combination. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Identification of titanium dioxide nanoparticles in food products: induce intracellular oxidative stress mediated by TNF and CYP1A genes in human lung fibroblast cells.

    Science.gov (United States)

    Periasamy, Vaiyapuri Subbarayan; Athinarayanan, Jegan; Al-Hadi, Ahmed M; Juhaimi, Fahad Al; Mahmoud, Mohamed H; Alshatwi, Ali A

    2015-01-01

    Food grade TiO2 (E171) is a synthetic additive, and widely used as a coloring agent in many foods, pharmaceutical and personal care products. A few reports have highlighted that insoluble particulates (less than 200nm) of food grade TiO2 are found in many foods and confectionary products. However, information regarding the physico-chemical properties (i.e., size and shape)-based food grade TiO2 nanotoxicity related human health issues are limited. The main goal of this study is to examine the presence of nano-sized particulates and its structural characteristics of food grade- TiO2 materials and to assess the acute cellular uptake and metabolic stress induced by these particulates in human lung fibroblast (WI-38) cells. The results of transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction studies indicated that about food grade TiO2 sample contains spherical shaped particulate forms in the nano-scale range, S>G0/G1) and changes in the TNF and CYP1A gene expression pattern are linked to cellular stress. Thus, food grade TiO2 as nano-scaled contaminants could not only be potential human health risk factors, suggesting that safety considerations with special respect to a few crucial factors such as size, and shape should be considered and regulated by food regulators. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Effects of titanium dioxide nanoparticles on human keratinocytes.

    Science.gov (United States)

    Wright, Clayton; Iyer, Anand Krishnan V; Wang, Liying; Wu, Nianqiang; Yakisich, Juan S; Rojanasakul, Yon; Azad, Neelam

    2017-01-01

    Titanium dioxide (TiO 2 ) is a ubiquitous whitening compound widely used in topical products such as sunscreens, lotions and facial creams. The damaging health effects of TiO 2 inhalation has been widely studied in rats, mice and humans showing oxidative stress increase, DNA damage, cell death and inflammatory gene upregulation in lung and throat cells; however, the effects on skin cells from long-term topical use of various products remain largely unknown. In this study, we assessed the effect of specific TiO 2 nanoparticles (H 2 TiO 7 ) on a human keratinocyte cell line (HaCaT). We performed a comparative analysis using three TiO 2 particles varying in size (Fine, Ultrafine and H 2 TiO 7 ) and analyzed their effects on HaCaTs. There is a clear dose-dependent increase in superoxide production, caspase 8 and 9 activity, and apoptosis in HaCaTs after treatment with all three forms of TiO 2 ; however, there is no consistent effect on cell viability and proliferation with either of these TiO 2 particles. While there is data suggesting UV exposure can enhance the carcinogenic effects of TiO 2 , we did not observe any significant effect of UV-C exposure combined with TiO 2 treatment on HaCaTs. Furthermore, TiO 2 -treated cells showed minimal effects on VEGF upregulation and Wnt signaling pathway thereby showing no potential effect on angiogenesis and malignant transformation. Overall, we report here an increase in apoptosis, which may be caspase 8/Fas-dependent, and that the H 2 TiO 7 nanoparticles, despite their smaller particle size, had no significant enhanced effect on HaCaT cells as compared to Fine and Ultrafine forms of TiO 2 .

  5. Toxicity Assessment of Six Titanium Dioxide Nanoparticles in Human Epidermal Keratinocytes

    Science.gov (United States)

    Toxicity Assessment of Six Titanium Dioxide Nanoparticles in Human Epidermal Keratinocytes Nanoparticle uptake in cells may be an important determinant of their potential cytotoxic and inflammatory effects. Six commercial TiO2 NP (A=Alfa Aesar,10nm, A*=Alfa Aesar 32nm, B=P25 27...

  6. Titanium Dioxide Nanoparticle-Biomolecule Interactions Influence Oral Absorption.

    Science.gov (United States)

    Jo, Mi-Rae; Yu, Jin; Kim, Hyoung-Jun; Song, Jae Ho; Kim, Kyoung-Min; Oh, Jae-Min; Choi, Soo-Jin

    2016-11-29

    Titanium dioxide (TiO₂) nanoparticles (NPs) have been widely applied in various industrial fields, such as electronics, packaging, food, and cosmetics. Accordingly, concerns about the potential toxicity of TiO₂ NPs have increased. In order to comprehend their in vivo behavior and potential toxicity, we must evaluate the interactions between TiO₂ NPs and biomolecules, which can alter the physicochemical properties and the fate of NPs under physiological conditions. In the present study, in vivo solubility, oral absorption, tissue distribution, and excretion kinetics of food grade TiO₂ (f-TiO₂) NPs were evaluated following a single-dose oral administration to rats and were compared to those of general grade TiO₂ (g-TiO₂) NPs. The effect of the interactions between the TiO₂ NPs and biomolecules, such as glucose and albumin, on oral absorption was also investigated, with the aim of determining the surface interactions between them. The intestinal transport pathway was also assessed using 3-dimensional culture systems. The results demonstrate that slightly higher oral absorption of f-TiO₂ NPs compared to g-TiO₂ NPs could be related to their intestinal transport mechanism by microfold (M) cells, however, most of the NPs were eliminated through the feces. Moreover, the biokinetics of f-TiO₂ NPs was highly dependent on their interaction with biomolecules, and the dispersibility was affected by modified surface chemistry.

  7. Titanium Dioxide Nanoparticles: a Risk for Human Health?

    Science.gov (United States)

    Grande, Fedora; Tucci, Paola

    2016-01-01

    Titanium dioxide (TiO2) is a natural oxide of the element titanium with low toxicity, and negligible biological effects. The classification as bio-inert material has given the possibility to normal-sized (>100 nm) titanium dioxide particles (TiO2-NPs) to be extensively used in food products and as ingredients in a wide range of pharmaceutical products and cosmetics, such as sunscreens and toothpastes. Therefore, human exposure may occur through ingestion and dermal penetration, or through inhalation route, during both the manufacturing process and use. In spite of the extensively use of TiO2-NPs, the biological effects and the cellular response mechanisms are still not completely elucidated and thus a deep understanding of the toxicological profile of this compound is required. The main mechanism underlining the toxicity potentially triggered by TiO2-NPs seems to involve the reactive oxygen species (ROS) production, resulting in oxidative stress, inflammation, genotoxicity, metabolic change and potentially carcinogenesis. The extent and type of cell damage strongly depend on chemical and physical characteristics of TiO2-NPs, including size, crystal structure and photo-activation. In this mini-review, we would like to discuss the latest findings on the adverse effects and on potential human health risks induced by TiO2-NPs exposure.

  8. An Enhanced Soft Vibrotactile Actuator Based on ePVC Gel with Silicon Dioxide Nanoparticles.

    Science.gov (United States)

    Park, Won-Hyeong; Shin, Eun-Jae; Yun, Sungryul; Kim, Sang-Youn

    2018-01-01

    In this paper, we propose a soft vibrotactile actuator made by mixing silicon dioxide nanoparticles and plasticized PVC gel. The effect of the silicon dioxide nanoparticles in the plasticized PVC gel for the haptic performance is investigated in terms of electric, dielectric, and mechanical properties. Furthermore, eight soft vibrotactile actuators are prepared as a function of the content. Experiments are conducted to examine the haptic performance of the prepared eight soft vibrotactile actuators and to find the best weight ratio of the plasticized PVC gel to the nanoparticles. The experiments should show that the plasticized PVC gel with silicon dioxide nanoparticles improves the haptic performance of the plasticized PVC gel-based vibrotactile actuator, and the proposed vibrotactile actuator can create a variety of haptic sensations in a wide frequency range.

  9. Redox-responsive manganese dioxide nanoparticles for enhanced MR imaging and radiotherapy of lung cancer

    Science.gov (United States)

    Cho, Mi Hyeon; Choi, Eun-Seok; Kim, Sehee; Goh, Sung-Ho; Choi, Yongdoo

    2017-12-01

    In this study, we synthesized manganese dioxide nanoparticles (MnO2 NPs) stabilized with biocompatible polymers (polyvinylpyrrolidone and polyacrylic acid) and analyzed their effect on non-small cell lung cancer (NSCLC) cells with or without gefitinib resistance in vitro. MnO2 NPs showed glutathione (GSH)-responsive dissolution and subsequent enhancement in magnetic resonance (MR) imaging. Of note, treatment with MnO2 NPs induced significant cytotoxic effects on NSCLC cells, and additional dose-dependent therapeutic effects were obtained upon X-ray irradiation. Normal cells treated with MnO2 NPs were viable at the tested concentrations. In addition, increased therapeutic efficacy could be achieved when the cells were treated with MnO2 NPs in hypoxic conditions. Therefore, we conclude that the use of MnO2 NPs in MR imaging and combination radiotherapy may be an efficient strategy for the imaging and therapy of NSCLC.

  10. Preparation of Heat Treated Titanium Dioxide (TiO2) Nanoparticles for Water Purification

    Science.gov (United States)

    Araoyinbo, A. O.; Abdullah, M. M. A. B.; Rahmat, A.; Azmi, A. I.; Vizureanu, P.; Rahim, W. M. F. Wan Abd

    2018-06-01

    Photocatalysis using the semiconductor titanium dioxide (TiO2) has proven to be a successful technology for waste water purification. The photocatalytic treatment is an alternative method for the removal of soluble organic compounds in waste water. In this research, titanium dioxide nanoparticles were synthesized by sol-gel method using titanium tetraisopropoxide (TTIP) as a precursor. The sol was dried in the oven at 120°C after aging for 24 hours. The dried powder was then calcined at 400°C and 700°C with a heating rate of 10°C/min. The phase transformation of the heat treated titanium dioxide nanoparticles were characterized by X-Ray Diffraction (XRD, and the surface morphology by Scanning Electron Microscopy (SEM). The photocatalytic activity of the heat treated titanium dioxide nanoparticles in the degradation of methyl orange (MO) dye under ultraviolet (UV) light irradiation has been studied. At calcination temperature of 400°C, only anatase phase was observed, as the calcination temperature increases to 700°C, the rutile phase was present. The SEM images show the irregular shape of titanium dioxide particles and the agglomeration which tends to be more significant at calcined temperature of 700°C. Degradation of methyl orange by 5 mg heat treated titanium dioxide nanoparticles gives the highest percentage of degradation after irradiation by UV lamp for 4 hours.

  11. Turkevich method for silver/titanium dioxide nanoparticles with antimicrobial application in polymers systems

    International Nuclear Information System (INIS)

    Olyveira, Gabriel Molina de; Pessan, Luiz Antonio

    2009-01-01

    Titanium dioxide nanoparticles were covered with silver nanoparticles using Turkevich Method or citrate reduction method. Silver and titanium dioxide has proved antimicrobial properties then the nanocomposite can be successful incorporated in polymer systems. Silver nitrate was reduced by sodium citrate in the presence of poly(vinyl pyrrolidone)(PVP) resulting in nano-Ag/TiO 2 stabilized suspension. It was tested ammonia hydroxide in the synthesis to avoid the nanoparticles growth. The Ag/TiO 2 nanoparticles were characterized with X-ray diffraction (XRD), Scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). The best system of coloidal nanoparticles was that one with Poly(vinyl pyrrolidone) and ammonia in the synthesis. (author)

  12. Alteration of metabolomic profiles by titanium dioxide nanoparticles in human gingivitis model.

    Science.gov (United States)

    Garcia-Contreras, Rene; Sugimoto, Masahiro; Umemura, Naoki; Kaneko, Miku; Hatakeyama, Yoko; Soga, Tomoyoshi; Tomita, Masaru; Scougall-Vilchis, Rogelio J; Contreras-Bulnes, Rosalia; Nakajima, Hiroshi; Sakagami, Hiroshi

    2015-07-01

    Although nanoparticles (NPs) has afforded considerable benefits in various fields of sciences, several reports have shown their harmful effects, suggesting the necessity of adequate risk assessment. To clarify the mechanism of titanium dioxide nanoparticles (TiO2 NPs)-enhanced gingival inflammation, we conducted the full-scale metabolomic analyses of human gingival fibroblast cells treated with IL-1β alone or in combination with TiO2 NPs. Observation with transmission electron microscope demonstrated the incorporation of TiO2 NPs into vacuoles of the cells. TiO2 NPs significantly enhanced the IL-1β-induced prostaglandin E2 production and COX-1 and COX-2 protein expression. IL-1β reduced the intracellular concentrations of overall primary metabolites especially those of amino acid, urea cycle, polyamine, S-adenosylmethione and glutathione synthetic pathways. The addition of TiO2 NPs further augmented these IL-1β-induced metabolic changes, recommending careful use of dental materials containing TiO2 NPs towards patients with gingivitis or periodontitis. The impact of the present study is to identify the molecular targets of TiO2 NPs for the future establishment of new metabolic markers and therapeutic strategy of gingival inflammation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Improved microbial growth inhibition activity of bio-surfactant induced Ag–TiO{sub 2} core shell nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nithyadevi, D. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046 (India); Kumar, P. Suresh [Thin Film and Nanomaterials Laboratory, Department of Physics, Bharathiar University, Coimbatore 641 046 (India); Mangalaraj, D., E-mail: dmraj800@yahoo.com [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046 (India); Ponpandian, N.; Viswanathan, C. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046 (India); Meena, P. [Department of Physics, PSGR Krishnammal college for women, Coimbatore 641 004 (India)

    2015-02-01

    Graphical abstract: - Highlights: • TiO{sub 2} nanoparticles were synthesized by hydrolysis process and Ag nanoparticles were prepared by using hydrazine reduction method. • Ag–TiO{sub 2} core shell nanoparticles were synthesized by reverse micelle method. • Coatings of TiO{sub 2} shell leads to decrease the usage of silver particles and also it reduces the release of silver ions from the matrix. • Optimum ratio of TiO{sub 2} particles: Ag atoms are needed for better antibacterial activity. • Sodium alginate (Bio-copolymer) induced core shell nanoparticles results 100% cell growth inhibition toward Staphylococcus aureus. - Abstract: Surfactant induced silver–titanium dioxide core shell nanoparticles within the size range of 10–50 nm were applied in the antibacterial agent to inhibit the growth of bacterial cells. The single crystalline silver was located in the core part of the composite powder and the titanium dioxide components were uniformly distributed in the shell part. HRTEM and XRD results indicated that silver was completely covered by titanium dioxide and its crystal structure was not affected after being coated by titanium dioxide. The effect of silver–titanium dioxide nanoparticles in the inhibition of bacterial cell growth was studied by means of disk diffusion method. The inhibition zone results reveal that sodium alginate induced silver–titanium dioxide nanoparticles exhibit 100% more antibacterial activity than that with cetyltrimethylbromide or without surfactant. UV–vis spectroscopic analysis showed a large concentration of silver was rapidly released into phosphate buffer solution (PBS) within a period of 1 day, with a much smaller concentration being released after this 1-day period. It was concluded that sodium alginate induced silver–titanium dioxide core shell nanoparticles could enhance long term cell growth inhibition in comparison with cetyltrimethylbromide or without surfactant. The surfactant mediated core shell

  14. Effect of Titanium dioxide nanoparticles on the flexural strength of polymethylmethacrylate: an in vitro study.

    Science.gov (United States)

    Harini, P; Mohamed, Kasim; Padmanabhan, T V

    2014-01-01

    To improve the flexural strength of polymethylmethacrylate (PMMA). To evaluate whether the incorporation of titanium dioxide nanoparticles in polymethylmethacrylate (PMMA) increases the flexural strength and to compare the different concentrations of titanium dioxide nanoparticles and its relation to flexural strength. Study was conducted in Sri Ramachandra University utilizing 40 specimens manufactured from clear heat polymerizing acrylic resin. Forty specimens of clear heat polymerizing acrylic resin of dimensions 65 Χ 10 Χ 3 mm as per ISO 1,567 standardization were fabricated and were grouped into A (CONTROL) with no titanium dioxide (TiO2) nanoparticles, B with 0.5 gms of TiO 2 nanoparticles, C with 1 gm of TiO 2 nanoparticles and D with 2.5 gms of TiO 2 nanoparticles added.The concentrations of titanium dioxide in each group were 1 wt%, 2 wt% and 5 wt%. Universal testing machine INSTRON was used to load at the center of the specimen with a cross head speed of 1.50 mm/min and a span length of 40.00 mm. ANOVA and multiple comparisons are carried out using the independent t-test. The ANOVA result shows that there is a significant difference between the groups with respect to the mean flexural strength. Highest mean flexural strength is observed in Group D, while the lowest is seen in Group A. Independent t-test revealed that there was a statistical significance between Group A and Group D (0.041) and between Group B and Group D (0.028). The results concluded that polymethylmethacrylate reinforced with different concentrations of titanium dioxide nanoparticles showed superior flexural strength than those of normal PMMA.

  15. Biotemplated Synthesis of Anatase Titanium Dioxide Nanoparticles via Lignocellulosic Waste Material

    Directory of Open Access Journals (Sweden)

    Donya Ramimoghadam

    2014-01-01

    Full Text Available Anatase titanium dioxide nanoparticles (TiO2-NPs were synthesized by sol-gel method using rice straw as a soft biotemplate. Rice straw, as a lignocellulosic waste material, is a biomass feedstock which is globally produced in high rate and could be utilized in an innovative approach to manufacture a value-added product. Rice straw as a reliable biotemplate has been used in the sol-gel method to synthesize ultrasmall sizes of TiO2-NPs with high potential application in photocatalysis. The physicochemical properties of titanium dioxide nanoparticles were investigated by a number of techniques such as X-ray diffraction analysis (XRD, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FTIR, Raman spectroscopy, thermogravimetric analysis (TGA, ultraviolet visible spectra (UV-Vis, and surface area and pore size analysis. All results consensually confirmed that particle sizes of synthesized titanium dioxide were template-dependent, representing decrease in the nanoparticles sizes with increase of biotemplate concentration. Titanium dioxide nanoparticles as small as 13.0 ± 3.3 nm were obtained under our experimental conditions. Additionally, surface area and porosity of synthesized TiO2-NPs have been enhanced by increasing rice straw amount which results in surface modification of nanoparticles and potential application in photocatalysis.

  16. Effects of titanium dioxide nanoparticles exposure on parkinsonism in zebrafish larvae and PC12.

    Science.gov (United States)

    Hu, Qinglian; Guo, Fengliang; Zhao, Fenghui; Fu, Zhengwei

    2017-04-01

    Nanomaterials hold significant potential for industrial and biomedical application these years. Therefore, the relationship between nanoparticles and neurodegenerative disease is of enormous interest. In this contribution, zebrafish embryos and PC12 cell lines were selected for studying neurotoxicity of titanium dioxide nanoparticles (TiO 2 NPs). After exposure of different concentrations of TiO 2 NPs to embryos from fertilization to 96 hpf, the hatching time of zebrafish was decreased, accompanied by an increase in malformation rate. However, no significant increases in mortality relative to control were observed. These results indicated that TiO 2 NPs exposure hold a risk for premature of zebrafish embryos, but not fatal. The further investigation confirmed that TiO 2 NPs could accumulate in the brain of zebrafish larvae, resulting in reactive oxygen species (ROS) generation and cell death of hypothalamus. Meanwhile, q-PCR analysis showed that TiO 2 NPs exposure increased the pink1, parkin, α-syn and uchl1 gene expression, which are related with the formation of Lewy bodies. We also observed loss of dopaminergic neurons in zebrafish and in vitro. These remarkable hallmarks are all linked to these Parkinson's disease (PD) symptoms. Our results indicate that TiO 2 NPs exposure induces neurotoxicity in vivo and in vitro, which poses a significant risk factor for the development of PD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Titanium dioxide encapsulation of supported Ag nanoparticles on the porous silica bead for increased photocatalytic activity

    Science.gov (United States)

    Liu, Hui; Deng, Lu; Sun, Chaochao; Li, Junqi; Zhu, Zhenfeng

    2015-01-01

    A new synthetic strategy has been developed to encapsulate Ag nanoparticles in heterogeneous catalysts to prevent their dropping and sintering. Ag nanoparticles with diameters about 5-10 nm were first supported on the porous silica bead. These were then covered with a fresh layer of titanium dioxide with the thickness about 5 nm. SEM and TEM images were used to confirm the success of each synthesis step, and the photocatalytic activity of the as-synthesized samples was evaluated by photocatalytic decolorization of Rhodamine B (Rh B) aqueous solution at ambient temperature under both UV and visible light irradiation. The resulting titanium dioxide encapsulated Ag nanoparticles exhibited an enhanced photocatalytic activity under both UV and visible light irradiation, this can be attributed to effective charge separation and light harvesting of the plasmonic silver nanoparticles decoration, even the reducing of the exciton recombination rate caused by the small grain size of anatase TiO2 nanocrystals.

  18. In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles

    OpenAIRE

    Farzin Heravi; Mohammad Ramezani; Maryam Poosti; Mohsen Hosseini; Arezoo Shajiei; Farzaneh Ahrari

    2013-01-01

    Background and aims. Incorporation of nano-particles to orthodontic bonding systems has been considered to prevent enamel demineralization around appliances. This study investigated cytotoxicity of Transbond XT adhesive containing 1 wt% titanium dioxide (TiO2) nano-particles. Materials and methods. Ten composite disks were prepared from each of the conventional and TiO2-containg composites and aged for 1, 3, 5, 7 and 14 days in Dulbecco’s Modified Eagle’s Medium (DMEM). The extrac...

  19. Heteroaggregation of titanium dioxide nanoparticles with natural clay colloids.

    Science.gov (United States)

    Labille, Jérôme; Harns, Carrie; Bottero, Jean-Yves; Brant, Jonathan

    2015-06-02

    To better understand and predict the fate of engineered nanoparticles in the water column, we assessed the heteroaggregation of TiO2 nanoparticles with a smectite clay as analogues for natural colloids. Heteroaggregation was evaluated as a function of water salinity (10(-3) and 10(-1) M NaCl), pH (5 and 8), and selected nanoparticle concentration (0-4 mg/L). Time-resolved laser diffraction was used, coupled to an aggregation model, to identify the key mechanisms and variables that drive the heteroaggregation of the nanoparticles with colloids. Our data show that, at a relevant concentration, nanoparticle behavior is mainly driven by heteroaggregation with colloids, while homoaggregation remains negligible. The affinity of TiO2 nanoparticles for clay is driven by electrostatic interactions. Opposite surface charges and/or high ionic strength favored the formation of primary heteroaggregates via the attachment of nanoparticles to the clay. The initial shape and dispersion state of the clay as well as the nanoparticle/clay concentration ratio also affected the nature of the heteroaggregation mechanism. With dispersed clay platelets (10(-3) M NaCl), secondary heteroaggregation driven by bridging nanoparticles occurred at a nanoparticle/clay number ratio of greater than 0.5. In 10(-1) M NaCl, the clay was preaggregated into larger and more spherical units. This favored secondary heteroaggregation at lower nanoparticle concentration that correlated to the nanoparticle/clay surface area ratio. In this latter case, a nanoparticle to clay sticking efficiency could be determined.

  20. Titanium dioxide nanoparticles activate IL8-related inflammatory pathways in human colonic epithelial Caco-2 cells

    Science.gov (United States)

    Krüger, Kristin; Cossais, François; Neve, Horst; Klempt, Martin

    2014-05-01

    Nanosized titanium dioxide (TiO2) particles are widely used as food additive or coating material in products of the food and pharmaceutical industry. Studies on various cell lines have shown that TiO2 nanoparticles (NPs) induced the inflammatory response and cytotoxicity. However, the influences of TiO2 NPs' exposure on inflammatory pathways in intestinal epithelial cells and their differentiation have not been investigated so far. This study demonstrates that TiO2 NPs with particle sizes ranging between 5 and 10 nm do not affect enterocyte differentiation but cause an activation of inflammatory pathways in the human colon adenocarcinoma cell line Caco-2. 5 and 10 nm NPs' exposures transiently induce the expression of ICAM1, CCL20, COX2 and IL8, as determined by quantitative PCR, whereas larger particles (490 nm) do not. Further, using nuclear factor (NF)-κB reporter gene assays, we show that NP-induced IL8 mRNA expression occurs, in part, through activation of NF-κB and p38 mitogen-activated protein kinase pathways.

  1. Immobilization of nanoparticle titanium dioxide membrane on polyamide fabric by low temperature hydrothermal method

    International Nuclear Information System (INIS)

    Zhang Hui; Yang Lu

    2012-01-01

    A thin layer of nanoparticle titanium dioxide was immobilized on polyamide 6 (PA6) fiber using titanium sulfate and urea at low temperature hydrothermal condition. The titanium dioxide loaded fabric was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry and thermal gravimetry techniques. The optical and mechanical properties, water absorption and degradation of methylene blue dye under ultraviolet (UV) irradiation of the PA6 fabric before and after treatments were also examined. It was found that when PA6 fabric was treated in titanium sulfate and urea aqueous solution, anatase nanocrystalline titanium dioxide was synthesized and simultaneously adhered onto the fiber surface. The average crystal size of titanium dioxide nanoparticles was about 13.2 nm. The thermal behavior of PA6 fiber distinctly changed and the onset decomposition temperature decreased. As compared with the untreated fabric, the protection against UV radiation was improved. The water absorbency increased slightly. As the fabric dimensions were reduced in warp and weft directions, the breaking load and tensile strain increased to some extent. The titanium dioxide coated fabric could degradate methylene blue dye under UV irradiation. - Highlights: ► We employed a method to immobilize TiO 2 nanoparticle on polyamide fiber. ► We fabricated the TiO 2 -coated polyamide fabric with the photocatalytic activity. ► The modification method may be suitable for the potential applications.

  2. Synthesis of Titanium Dioxide Nanoparticles Using a Double-Slit Curved Wall-Jet Burner

    KAUST Repository

    Ismail, Mohamed

    2016-05-04

    A novel double-slit curved wall-jet (DS-CWJ) burner was proposed and utilized for flame synthesis. This burner was comprised of double curved wall-jet nozzles with coaxial slits; the inner slit was for the delivery of titanium tetraisopropoxide (TTIP) precursor while the outer one was to supply premixed fuel/air mixture of ethylene (C2H4) or propane (C3H8). This configuration enabled rapid mixing between the precursor and reactants along the curved surface and inside the recirculation zone of the burner. Particle growth of titanium dioxide (TiO2) nanoparticles and their phases was investigated with varying equivalence ratio and Reynolds number. Flow field and flame structure were measured using particle image velocimetry (PIV) and OH planar laser-induced fluorescence (PLIF) techniques, respectively. The nanoparticles were characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and nitrogen adsorption Brunauer–Emmett–Teller (BET) for surface area analysis. The flow field consisted of a wall-jet region leading to a recirculation zone, an interaction jet region, followed by a merged-jet region. The DS-CWJ burner revealed appreciable mixing characteristics between the precursor and combustion gases near the nozzle regions, with a slight increase in the axial velocity due to the precursor injection. The precursor supply had a negligible effect on the flame structure. The burner produced a reasonably uniform size (13–18 nm) nanoparticles with a high BET surface area (>100 m2/g). The phase of TiO2 nanoparticles was mainly dependent on the equivalence ratio and fuel type, which impact flame height, heat release rate, and high temperature residence time of the precursor vapor. For ethylene flames, the anatase content increased with the equivalence ratio, whereas it decreased in the case of propane flames. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence

  3. Photocatalytic ROS production and phototoxicity of titanium dioxide nanoparticles is dependent on solar UV radiation spectrum

    Science.gov (United States)

    Generation of reactive oxygen species (ROS) by titanium dioxide nanoparticles (nano-TiO2) and its consequent phototoxicity to Daphnia magna were measured under different solar UV radiation spectrum by applying a series of optical filters in a solar simulator. Removing UVB (280-32...

  4. Impact of natural organic matter on particle behavior and phototoxicity of titanium dioxide nanoparticles

    Science.gov (United States)

    Due to their inherent phototoxicity and inevitable environmental release, titanium dioxide nanoparticles (nano-TiO2) are increasingly studied in the field of aquatic toxicology. One of the particular interests is the interactions between nano-TiO2 and natural organic matter (NOM)...

  5. Effects of titanium dioxide nanoparticles on red clover and its rhizobial symbiont

    NARCIS (Netherlands)

    Moll, Janine; Okupnik, Annette; Gogos, Alexander; Knauer, Katja; Bucheli, Thomas D.; Van Der Heijden, Marcel G A; Widmer, Franco

    2016-01-01

    Titanium dioxide nanoparticles (TiO2 NPs) are in consideration to be used in plant protection products. Before these products can be placed on the market, ecotoxicological tests have to be performed. In this study, the nitrogen fixing bacterium Rhizobium trifolii and red clover were exposed to two

  6. Effects of titanium dioxide nanoparticles on soil microbial communities and wheat biomass

    NARCIS (Netherlands)

    Moll, Janine; Klingenfuss, Florian; Widmer, Franco; Gogos, Alexander; Bucheli, Thomas D.; Hartmann, Martin; van der Heijden, Marcel G.A.

    2017-01-01

    Titanium dioxide nanoparticles (TiO2 NPs) are the most produced NPs worldwide and have great potential to be utilized in agriculture as additives for plant protection products. However, concerns have been raised that some NPs may negatively affect crops and soil microbial communities, including

  7. Polymorph-dependent titanium dioxide nanoparticle dissolution in acidic and alkali digestions

    Science.gov (United States)

    Multiple polymorphs (anatase, brookite and rutile) of titanium dioxide nanoparticles (TiO2-NPs) with variable structures were quantified in environmental matrices via microwave-based hydrofluoric (HF) and nitric (HNO3) mixed acid digestion and muffle furnace (MF)-based potassium ...

  8. Phenotypic and genomic responses to titanium dioxide and cerium oxide nanoparticles in Arabidopsis germinants

    Science.gov (United States)

    The effects of exposure to two nanoparticles (NPs) -titanium dioxide (nano-titania) and cerium oxide (nano-ceria) at 500 mg NPs L-1 on gene expression and growth in Arabidopsis thaliana germinants were studied using microarrays and phenotype studies. After 12 days post treatment,...

  9. Study of Dielectric Properties and Morphology of Epoxy Resin with Silicon Dioxide Microparticles and Nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Hudec, Jiří; Neděla, Vilém

    2016-01-01

    Roč. 22, S3 (2016), s. 1896-1897 ISSN 1431-9276 R&D Projects: GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : epoxy resin ESEM * Nanoparticles * silicon dioxide * ESEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.891, year: 2016

  10. Cavitation-induced reactions in high-pressure carbon dioxide

    NARCIS (Netherlands)

    Kuijpers, M.W.A.; van Eck, D.; Kemmere, M.F.; Keurentjes, J.T.F.

    2002-01-01

    The feasibility of ultrasound-induced in situ radical formation in liquid carbon dioxide was demonstrated. The required threshold pressure for cavitation could be exceeded at a relatively low acoustic intensity, as the high vapor pressure of CO2 counteracts the hydrostatic pressure. With the use of

  11. A mechanistic study to increase understanding of titanium dioxide nanoparticles-increased plasma glucose in mice.

    Science.gov (United States)

    Hu, Hailong; Li, Li; Guo, Qian; Jin, Sanli; Zhou, Ying; Oh, Yuri; Feng, Yujie; Wu, Qiong; Gu, Ning

    2016-09-01

    Titanium dioxide nanoparticle (TiO2 NP) is an authorized food additive. Previous studies determined oral administration of TiO2 NPs increases plasma glucose in mice via inducing insulin resistance. An increase in reactive oxygen species (ROS) has been considered the possible mechanism of increasing plasma glucose. However, persistently high plasma glucose is also a mechanism of increasing ROS. This study aims to explore whether TiO2 NPs increase plasma glucose via ROS. We found after oral administration of TiO2 NPs, an increase in ROS preceded an increase in plasma glucose. Subsequently, mice were treated with two antioxidants (resveratrol and vitamin E) at the same time as oral administration of TiO2 NPs. Results showed resveratrol and vitamin E reduced TiO2 NPs-increased ROS. An increase in plasma glucose was also inhibited. Further research showed resveratrol and vitamin E inhibited the secretion of TNF-α and IL-6, and the phosphorylation of JNK and p38 MAPK, resulting in improved insulin resistance. These results suggest TiO2 NPs increased ROS levels, and then ROS activated inflammatory cytokines and phosphokinases, and thus induced insulin resistance, resulting in an increase in plasma glucose. Resveratrol and vitamin E can reduce TiO2 NPs-increased ROS and thereby inhibit an increase in plasma glucose in mice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. The effect of titanium dioxide nanoparticles on neuroinflammation response in rat brain.

    Science.gov (United States)

    Grissa, Intissar; Guezguez, Sabrine; Ezzi, Lobna; Chakroun, Sana; Sallem, Amira; Kerkeni, Emna; Elghoul, Jaber; El Mir, Lassaad; Mehdi, Meriem; Cheikh, Hassen Ben; Haouas, Zohra

    2016-10-01

    Titanium dioxide nanoparticles (TiO 2 NPs) are widely used for their whiteness and opacity in several applications such as food colorants, drug additives, biomedical ceramic, and implanted biomaterials. Research on the neurobiological response to orally administered TiO 2 NPs is still limited. In our study, we investigate the effects of anatase TiO 2 NPs on the brain of Wistar rats after oral intake. After daily intragastric administration of anatase TiO 2 NPs (5-10 nm) at 0, 50, 100, and 200 mg/kg body weight (BW) for 60 days, the coefficient of the brain, acethylcholinesterase (AChE) activities, the level of interleukin 6 (IL-6), and the expression of glial fibrillary acidic protein (GFAP) were assessed to quantify the brain damage. The results showed that high-dose anatase TiO 2 NPs could induce a downregulated level of AChE activities and showed an increase in plasmatic IL-6 level as compared to the control group accompanied by a dose-dependent decrease inter-doses, associated to an increase in the cerebral IL-6 level as a response to a local inflammation in brain. Furthermore, we observed elevated levels of immunoreactivity to GFAP in rat cerebral cortex. We concluded that oral intake of anatase TiO 2 NPs can induce neuroinflammation and could be neurotoxic and hazardous to health.

  13. Titanium dioxide nanoparticles increase sensitivity in the next generation of the water flea Daphnia magna.

    Directory of Open Access Journals (Sweden)

    Mirco Bundschuh

    Full Text Available The nanoparticle industry is expected to become a trillion dollar business in the near future. Therefore, the unintentional introduction of nanoparticles into the environment is increasingly likely. However, currently applied risk-assessment practices require further adaptation to accommodate the intrinsic nature of engineered nanoparticles. Combining a chronic flow-through exposure system with subsequent acute toxicity tests for the standard test organism Daphnia magna, we found that juvenile offspring of adults that were previously exposed to titanium dioxide nanoparticles exhibit a significantly increased sensitivity to titanium dioxide nanoparticles compared with the offspring of unexposed adults, as displayed by lower 96 h-EC(50 values. This observation is particularly remarkable because adults exhibited no differences among treatments in terms of typically assessed endpoints, such as sensitivity, number of offspring, or energy reserves. Hence, the present study suggests that ecotoxicological research requires further development to include the assessment of the environmental risks of nanoparticles for the next and hence not directly exposed generation, which is currently not included in standard test protocols.

  14. Human in vivo and in vitro studies on gastrointestinal absorption of titanium dioxide nanoparticles.

    Science.gov (United States)

    Jones, Kate; Morton, Jackie; Smith, Ian; Jurkschat, Kerstin; Harding, Anne-Helen; Evans, Gareth

    2015-03-04

    The study was designed to conduct human in vivo and in vitro studies on the gastrointestinal absorption of nanoparticles, using titanium dioxide as a model compound, and to compare nanoparticle behaviour with that of larger particles. A supplier's characterisation data may not fully describe a particle formulation. Most particles tested agreed with their supplied characterisation when assessed by particle number but significant proportions of 'nanoparticle formulations' were particles >100nm when assessed by particle weight. Oral doses are measured by weight and it is therefore important that the weight characterisation is taken into consideration. The human volunteer studies demonstrated that very little titanium dioxide is absorbed gastrointestinally after an oral challenge. There was no demonstrable difference in absorption for any of the three particle sizes tested. All tested formulations were shown to agglomerate in simulated gastric fluid, particularly in the smaller particle formulations. Further agglomeration was observed when dispersing formulations in polymeric or elemental foods. Virtually no translocation of titanium dioxide particles across the cell layer was demonstrated. This study found no evidence that nanoparticulate titanium dioxide is more likely to be absorbed in the gut than micron-sized particles. Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.

  15. Influence Of Carboxymethyl Cellulose For The Transport Of Titanium Dioxide Nanoparticles In Clean Silica And Mineral-Coated Sands

    Science.gov (United States)

    The transport properties of titanium dioxide (anatase polymorph) nanoparticles encapsulated by carboxymethyl cellulose (CMC) were evaluated as a function of changes in the solute chemical properties in clean quartz, amorphous aluminum and iron hydroxide-coated sands. While prist...

  16. Synthesis of Titanium Dioxide nanoparticles via sucrose ester micelle-mediated hydrothermal processing route

    International Nuclear Information System (INIS)

    Anwar, N.S.; Kassim, A.; Lim, H.N.; Zakarya, S.A.; Huang, N.M.

    2010-01-01

    Titanium dioxide nanoparticles were synthesized via low-temperature sucrose ester micelle-mediated hydrothermal processing route using titanium isopropoxide as the precursor. X-ray diffractometer revealed that the samples possessed a mixed crystalline phases consisting of anatase and brookite in which anatase was the main phase. Upon increasing the hydrothermal reaction temperature, the degree of crystallinity of the nanoparticles improved and their morphology transformed from bundles of needles to rods and to spheres. Photo catalytic behaviour of the as-synthesized nanoparticles was investigated by photodegradation of methylene blue solution in an ultraviolet A irradiating photo reactor. The as-synthesized nanoparticles exhibited higher photo catalytic performance as compared to the commercial counterpart. (author)

  17. Titanium Dioxide Nanoparticles (TiO2 Quenching Based Aptasensing Platform: Application to Ochratoxin A Detection

    Directory of Open Access Journals (Sweden)

    Atul Sharma

    2015-09-01

    Full Text Available We demonstrate for the first time, the development of titanium dioxide nanoparticles (TiO2 quenching based aptasensing platform for detection of target molecules. TiO2 quench the fluorescence of FAM-labeled aptamer (fluorescein labeled aptamer upon the non-covalent adsorption of fluorescent labeled aptamer on TiO2 surface. When OTA interacts with the aptamer, it induced aptamer G-quadruplex complex formation, weakens the interaction between FAM-labeled aptamer and TiO2, resulting in fluorescence recovery. As a proof of concept, an assay was employed for detection of Ochratoxin A (OTA. At optimized experimental condition, the obtained limit of detection (LOD was 1.5 nM with a good linearity in the range 1.5 nM to 1.0 µM for OTA. The obtained results showed the high selectivity of assay towards OTA without interference to structurally similar analogue Ochratoxin B (OTB. The developed aptamer assay was evaluated for detection of OTA in beer sample and recoveries were recorded in the range from 94.30%–99.20%. Analytical figures of the merits of the developed aptasensing platform confirmed its applicability to real samples analysis. However, this is a generic aptasensing platform and can be extended for detection of other toxins or target analyte.

  18. Titanium Dioxide Nanoparticles (TiO₂) Quenching Based Aptasensing Platform: Application to Ochratoxin A Detection.

    Science.gov (United States)

    Sharma, Atul; Hayat, Akhtar; Mishra, Rupesh K; Catanante, Gaëlle; Bhand, Sunil; Marty, Jean Louis

    2015-09-22

    We demonstrate for the first time, the development of titanium dioxide nanoparticles (TiO₂) quenching based aptasensing platform for detection of target molecules. TiO₂ quench the fluorescence of FAM-labeled aptamer (fluorescein labeled aptamer) upon the non-covalent adsorption of fluorescent labeled aptamer on TiO₂ surface. When OTA interacts with the aptamer, it induced aptamer G-quadruplex complex formation, weakens the interaction between FAM-labeled aptamer and TiO₂, resulting in fluorescence recovery. As a proof of concept, an assay was employed for detection of Ochratoxin A (OTA). At optimized experimental condition, the obtained limit of detection (LOD) was 1.5 nM with a good linearity in the range 1.5 nM to 1.0 µM for OTA. The obtained results showed the high selectivity of assay towards OTA without interference to structurally similar analogue Ochratoxin B (OTB). The developed aptamer assay was evaluated for detection of OTA in beer sample and recoveries were recorded in the range from 94.30%-99.20%. Analytical figures of the merits of the developed aptasensing platform confirmed its applicability to real samples analysis. However, this is a generic aptasensing platform and can be extended for detection of other toxins or target analyte.

  19. Unraveling the neurotoxicity of titanium dioxide nanoparticles: focusing on molecular mechanisms

    Directory of Open Access Journals (Sweden)

    Bin Song

    2016-04-01

    Full Text Available Titanium dioxide nanoparticles (TiO2 NPs possess unique characteristics and are widely used in many fields. Numerous in vivo studies, exposing experimental animals to these NPs through systematic administration, have suggested that TiO2 NPs can accumulate in the brain and induce brain dysfunction. Nevertheless, the exact mechanisms underlying the neurotoxicity of TiO2 NPs remain unclear. However, we have concluded from previous studies that these mechanisms mainly consist of oxidative stress (OS, apoptosis, inflammatory response, genotoxicity, and direct impairment of cell components. Meanwhile, other factors such as disturbed distributions of trace elements, disrupted signaling pathways, dysregulated neurotransmitters and synaptic plasticity have also been shown to contribute to neurotoxicity of TiO2 NPs. Recently, studies on autophagy and DNA methylation have shed some light on possible mechanisms of nanotoxicity. Therefore, we offer a new perspective that autophagy and DNA methylation could contribute to neurotoxicity of TiO2 NPs. Undoubtedly, more studies are needed to test this idea in the future. In short, to fully understand the health threats posed by TiO2 NPs and to improve the bio-safety of TiO2 NPs-based products, the neurotoxicity of TiO2 NPs must be investigated comprehensively through studying every possible molecular mechanism.

  20. Comparative study on effects of two different types of titanium dioxide nanoparticles on human neuronal cells.

    Science.gov (United States)

    Valdiglesias, Vanessa; Costa, Carla; Sharma, Vyom; Kiliç, Gözde; Pásaro, Eduardo; Teixeira, João Paulo; Dhawan, Alok; Laffon, Blanca

    2013-07-01

    Titanium dioxide (TiO2) are among most frequently used nanoparticles (NPs). They are present in a variety of consumer products, including food industry in which they are employed as an additive. The potential toxic effects of these NPs on mammal cells have been extensively studied. However, studies regarding neurotoxicity and specific effects on neuronal systems are very scarce and, to our knowledge, no studies on human neuronal cells have been reported so far. Therefore, the main objective of this work was to investigate the effects of two types of TiO₂ NPs, with different crystalline structure, on human SHSY5Y neuronal cells. After NPs characterization, a battery of assays was performed to evaluate the viability, cytotoxicity, genotoxicity and oxidative damage in TiO₂ NP-exposed SHSY5Y cells. Results obtained showed that the behaviour of both types of NPs resulted quite comparable. They did not reduce the viability of neuronal cells but were effectively internalized by the cells and induced dose-dependent cell cycle alterations, apoptosis by intrinsic pathway, and genotoxicity not related with double strand break production. Furthermore, all these effects were not associated with oxidative damage production and, consequently, further investigations on the specific mechanisms underlying the effects observed in this study are required. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. In vitro cytotoxicity of biosynthesized titanium dioxide nanoparticles ...

    African Journals Online (AJOL)

    ISSN: 1596-5996 (print); 1596-9827 (electronic) ... dioxide (Ti(OH)2) (80 mL) in aqueous solution with stirring for 2 h at room temperature. The TiO2 NPs ... The TiO2 NPs showed dose-dependent cytotoxicity towards D145 cells. Keywords: .... with ethanol and chloroform, and dried at room ... oxidation state of the TiO2 NPs.

  2. ARSENIC REMOVAL USING SOL-GEL SYNTHESIZED TITANIUM DIOXIDE NANOPARTICLES

    Science.gov (United States)

    In this study, the effectiveness of TiO2 nanoparticles in arsenic adsorption was examined. TiO2 particles (LS) were synthesized via sol-gel techniques and characterized for their crystallinity, surface area and pore volume. Batch adsorption studies were perf...

  3. Magnetic induced heating of nanoparticle solutions

    Energy Technology Data Exchange (ETDEWEB)

    Murph, S. Hunyadi [Savannah River Site (SRS), Aiken, SC (United States); Univ. of Georgia, Athens, GA (United States); Brown, M. [Savannah River Site (SRS), Aiken, SC (United States); Coopersmith, K. [Savannah River Site (SRS), Aiken, SC (United States); Fulmer, S. [Savannah River Site (SRS), Aiken, SC (United States); Sessions, H. [Savannah River Site (SRS), Aiken, SC (United States); Ali, M. [Univ. of South Carolina, Columbia, SC (United States)

    2016-12-02

    Magnetic induced heating of nanoparticles (NP) provides a useful advantage for many energy transfer applications. This study aims to gain an understanding of the key parameters responsible for maximizing the energy transfer leading to nanoparticle heating through the use of simulations and experimental results. It was found that magnetic field strength, NP concentration, NP composition, and coil size can be controlled to generate accurate temperature profiles in NP aqueous solutions.

  4. Pro-inflammatory responses of RAW264.7 macrophages when treated with ultralow concentrations of silver, titanium dioxide, and zinc oxide nanoparticles

    International Nuclear Information System (INIS)

    Giovanni, Marcella; Yue, Junqi; Zhang, Lifeng; Xie, Jianping; Ong, Choon Nam; Leong, David Tai

    2015-01-01

    Highlights: • Ultralow levels of common nanoparticles exist in environment and consumer products. • Common nanoparticles at ultralow levels induce mild pro-inflammation by macrophages. • The nanoparticles are cytotoxic only at high doses. - Abstract: To cellular systems, nanoparticles are considered as foreign particles. Upon particles and cells contact, innate immune system responds by activating the inflammatory pathway. However, excessive inflammation had been linked to various diseases ranging from allergic responses to cancer. Common nanoparticles, namely silver, titanium dioxide, and zinc oxide exist in the environment as well as in consumer products at ultralow level of 10 −6 –10 −3 μg mL −1 . However, so far the risks of such low NPs concentrations remain unexplored. Therefore, we attempted to screen the pro-inflammatory responses after ultralow concentration treatments of the three nanoparticles on RAW264.7 macrophages, which are a part of the immune system, at both cellular and gene levels. Even though cytotoxicity was only observed at nanoparticles concentrations as high as 10 μg mL −1 , through the level of NF-κB and upregulation of pro-inflammatory genes, we observed activation of the induction of genes encoding pro-inflammatory cytokines starting already at 10 −7 μg mL −1 . This calls for more thorough characterization of nanoparticles in the environment as well as in consumer products to ascertain the health and safety of the consumers and living systems in general

  5. Phase study of titanium dioxide nanoparticle prepared via sol-gel process

    Science.gov (United States)

    Oladeji Araoyinbo, Alaba; Bakri Abdullah, Mohd Mustafa Al; Salleh, Mohd Arif Anuar Mohd; Aziz, Nurul Nadia Abdul; Iskandar Azmi, Azwan

    2018-03-01

    In this study, titanium dioxide nanoparticles have been prepared via sol-gel process using titanium tetraisopropoxide as a precursor with hydrochloric acid as a catalyst, and ethanol with deionized water as solvents. The value of pH used is set to 3, 7 and 8. The sols obtained were dried at 100 °C for 1 hr and calcined at 350, 550, and 750 °C for 3 hrs to observe the phase transformation of titanium dioxide nanoparticle. The samples were characterized by x-ray diffraction and field emission scanning electron microscope. The morphology analysis is obtained from field emission scanning electron microscope. The phase transformation was investigated by x-ray diffraction. It was found that the pH of the solution affect the agglomeration of titanium dioxide particle. The x-ray diffraction pattern of titanium dioxide shows the anatase phase most abundant at temperature of 350 °C. At temperature of 550 °C the anatase and rutile phase were present. At temperature of 750 °C the rutile phase was the most abundant for pH 3, 7 and 8. It was confirmed that at higher temperature the rutile phase which is the stable phase are mostly present.

  6. Titanium dioxide nanoparticles modulate the toxicological response to cadmium in the gills of Mytilus galloprovincialis

    International Nuclear Information System (INIS)

    Della Torre, Camilla; Balbi, Teresa; Grassi, Giacomo; Frenzilli, Giada; Bernardeschi, Margherita; Smerilli, Arianna; Guidi, Patrizia; Canesi, Laura; Nigro, Marco; Monaci, Fabrizio; Scarcelli, Vittoria; Rocco, Lucia; Focardi, Silvano; Monopoli, Marco; Corsi, Ilaria

    2015-01-01

    Highlights: • Nano-TiO 2 modulate CdCl 2 cellular responses in gills of marine mussel. • Nano-TiO 2 reduced CdCl 2 -induced effects by lowering abcb1 m-RNA and GST activity. • Nano-TiO 2 reduced Cd accumulation in mussel’s gills but not in whole soft tissue. • Higher accumulation of Ti in the presence of CdCl 2 was observed in gills. - Abstract: We investigated the influence of titanium dioxide nanoparticles (nano-TiO 2 ) on the response to cadmium in the gills of the marine mussel Mytilus galloprovincialis in terms of accumulation and toxicity. Mussels were in vivo exposed to nano-TiO 2 , CdCl 2 , alone and in combination. Several cellular biomarkers were investigated in gills: ABC transport proteins and metallothioneins at gene/protein (abcb1, abcc-like and mt-20) and functional level, GST activity, NO production and DNA damage (Comet assay). Accumulation of total Cd and titanium in gills as in whole soft tissue was also investigated. Significant responses to Cd exposure were observed in mussel gills as up-regulation of abcb1 and mt-20 gene transcription, increases in total MT content, P-gp efflux and GST activity, DNA damage and NO production. Nano-TiO 2 alone increased P-gp efflux activity and NO production. When combined with Cd, nano-TiO 2 reduced the metal-induced effects by significantly lowering abcb1 gene transcription, GST activity, and DNA damage, whereas, additive effects were observed on NO production. A lower concentration of Cd was observed in the gills upon co-exposure, whereas, Ti levels were unaffected. A competitive effect in uptake/accumulation of nano-TiO 2 and Cd seems to occur in gills. A confirmation is given by the observed absence of adsorption of Cd onto nano-TiO 2 in sea water media

  7. The effect of titanium dioxide nanoparticles on pulmonary surfactant function and ultrastructure

    Directory of Open Access Journals (Sweden)

    Braun Armin

    2009-09-01

    Full Text Available Abstract Background Pulmonary surfactant reduces surface tension and is present at the air-liquid interface in the alveoli where inhaled nanoparticles preferentially deposit. We investigated the effect of titanium dioxide (TiO2 nanosized particles (NSP and microsized particles (MSP on biophysical surfactant function after direct particle contact and after surface area cycling in vitro. In addition, TiO2 effects on surfactant ultrastructure were visualized. Methods A natural porcine surfactant preparation was incubated with increasing concentrations (50-500 μg/ml of TiO2 NSP or MSP, respectively. Biophysical surfactant function was measured in a pulsating bubble surfactometer before and after surface area cycling. Furthermore, surfactant ultrastructure was evaluated with a transmission electron microscope. Results TiO2 NSP, but not MSP, induced a surfactant dysfunction. For TiO2 NSP, adsorption surface tension (γads increased in a dose-dependent manner from 28.2 ± 2.3 mN/m to 33.2 ± 2.3 mN/m (p min slightly increased from 4.8 ± 0.5 mN/m up to 8.4 ± 1.3 mN/m (p 2 NSP concentrations. Presence of NSP during surface area cycling caused large and significant increases in both γads (63.6 ± 0.4 mN/m and γmin (21.1 ± 0.4 mN/m. Interestingly, TiO2 NSP induced aberrations in the surfactant ultrastructure. Lamellar body like structures were deformed and decreased in size. In addition, unilamellar vesicles were formed. Particle aggregates were found between single lamellae. Conclusion TiO2 nanosized particles can alter the structure and function of pulmonary surfactant. Particle size and surface area respectively play a critical role for the biophysical surfactant response in the lung.

  8. Titanium dioxide nanoparticles as guardian against environmental carcinogen benzo[alpha]pyrene.

    Directory of Open Access Journals (Sweden)

    Anupam Dhasmana

    Full Text Available Polycyclic aromatic hydrocarbons (PAH, like Benzo[alpha]Pyrene (BaP are known to cause a number of toxic manifestations including lung cancer. As Titanium dioxide Nanoparticles (TiO2 NPs have recently been shown to adsorb a number of PAHs from soil and water, we investigated whether TiO2 NPs could provide protection against the BaP induced toxicity in biological system. A549 cells when co-exposed with BaP (25 µM, 50 µM and 75 µM along with 0.1 µg/ml,0.5 µg/ml and 1 µg/ml of TiO2 NPs, showed significant reduction in the toxic effects of BaP, as measured by Micronucleus Assay, MTT Assay and ROS Assay. In order to explore the mechanism of protection by TiO2 NP against BaP, we performed in silico studies. BaP and other PAHs are known to enter the cell via aromatic hydrocarbon receptor (AHR. TiO2 NP showed a much higher docking score with AHR (12074 as compared to the docking score of BaP with AHR (4600. This indicates a preferential binding of TiO2 NP with the AHR, in case if both the TiO2 NP and BaP are present. Further, we have done the docking of BaP with the TiO2 NP bound AHR-complex (score 4710, and observed that BaP showed strong adsorption on TiO2 NP itself, and not at its original binding site (at AHR. TiO2 NPs thereby prevent the entry of BaP in to the cell via AHR and hence protect cells against the deleterious effects induced by BaP.

  9. Evaluation of coexposure to inorganic arsenic and titanium dioxide nanoparticles in the marine shrimp Litopenaeus vannamei.

    Science.gov (United States)

    Cordeiro, Lucas; Müller, Larissa; Gelesky, Marcos A; Wasielesky, Wilson; Fattorini, Daniele; Regoli, Francesco; Monserrat, José Marìa; Ventura-Lima, Juliane

    2016-01-01

    The acute toxicity of titanium dioxide nanoparticles (nTiO2) that occur concomitantly in the aquatic environment with other contaminants such as arsenic (As) is little known in crustaceans. The objective of the present study is to evaluate whether coexposure to nTiO2 can influence the accumulation, metabolism, and oxidative stress parameters induced by arsenic exposure in the gills and hepatopancreas of the shrimp Litopenaeus vannamei. Organisms were exposed by dissolving chemicals in seawater (salinity = 30) at nominal concentrations of 10 μg/L nTiO2 or As(III), dosed alone and in combination. Results showed that there was not a significant accumulation of As in either tissue type, but the coexposure altered the pattern of the metabolism. In the hepatopancreas, no changes were observed in the biochemical response, while in the gills, an increase in the glutamate-cysteine-ligase (GCL) activity was observed upon exposure to As or nTiO2 alone, an increase in the reduced glutathione (GSH) levels was observed upon exposure to As alone, and an increase in the total antioxidant capacity was observed upon exposure to nTiO2 or nTiO2 + As. However, these modulations were not sufficient enough to prevent the lipid damage induced by nTiO2 exposure. Our results suggest that coexposure to nTiO2 and As does not alter the toxicity of this metalloid in the gills and hepatopancreas of L. vannamei but does alter its metabolism, favoring its accumulation of organic As species considered moderately toxic.

  10. Effect of titanium dioxide nanoparticles on the cardiovascular system after oral administration.

    Science.gov (United States)

    Chen, Zhangjian; Wang, Yun; Zhuo, Lin; Chen, Shi; Zhao, Lin; Luan, Xianguo; Wang, Haifang; Jia, Guang

    2015-12-03

    Titanium dioxide nanoparticles (TiO2 NPs) have been widely used in various consumer products, especially food and personal care products. Compared to the well-characterized adverse cardiovascular effect of inhaled ambient ultrafine particles, research on the health response to orally administrated TiO2 NPs is still limited. In our study, we performed an in vivo study in Sprague-Dawley rats to understand the cardiovascular effect of TiO2 NPs after oral intake. After daily gastrointestinal administration of TiO2 NPs at 0, 2, 10, 50 mg/kg for 30 and 90 days, heart rate (HR), blood pressure, blood biochemical parameters and histopathology of cardiac tissues was assessed to quantify cardiovascular damage. Mild and temporary reduction of HR and systolic blood pressure as well as an increase of diastolic blood pressure was observed after daily oral administration of TiO2 NPs for 30 days. Injury of cardiac function was observed after daily oral administration of TiO2 NPs for 90 days as reflected in decreased activities of lactate dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (HBDH) and creatine kinase (CK). Increased white blood cells count (WBC) and granulocytes (GRN) in blood as well as increased concentrations of tumor necrosis factor α (TNF α) and interleukin 6 (IL-6) in the serum indicated inflammatory response initiated by TiO2 NPs exposure. It was hypothesize that cardiac damage and inflammatory response are the possible mechanisms of the adverse cardiovascular effects induced by orally administrated TiO2 NPs. Data from our study suggested that even at low dose of TiO2 NPs can induce adverse cardiovascular effects after 30 days or 90 days of oral exposure, thus warranting concern for the dietary intake of TiO2 NPs for consumers. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Titanium Dioxide Nanoparticles As Guardian against Environmental Carcinogen Benzo[alpha]Pyrene

    Science.gov (United States)

    Dhasmana, Anupam; Sajid Jamal, Qazi Mohd.; Mir, Snober Shabnam; Bhatt, Madan Lal Bramha; Rahman, Qamar; Gupta, Richa; Siddiqui, Mohd. Haris; Lohani, Mohtashim

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAH), like Benzo[alpha]Pyrene (BaP) are known to cause a number of toxic manifestations including lung cancer. As Titanium dioxide Nanoparticles (TiO2 NPs) have recently been shown to adsorb a number of PAHs from soil and water, we investigated whether TiO2 NPs could provide protection against the BaP induced toxicity in biological system. A549 cells when co-exposed with BaP (25 µM, 50 µM and 75 µM) along with 0.1 µg/ml,0.5 µg/ml and 1 µg/ml of TiO2 NPs, showed significant reduction in the toxic effects of BaP, as measured by Micronucleus Assay, MTT Assay and ROS Assay. In order to explore the mechanism of protection by TiO2 NP against BaP, we performed in silico studies. BaP and other PAHs are known to enter the cell via aromatic hydrocarbon receptor (AHR). TiO2 NP showed a much higher docking score with AHR (12074) as compared to the docking score of BaP with AHR (4600). This indicates a preferential binding of TiO2 NP with the AHR, in case if both the TiO2 NP and BaP are present. Further, we have done the docking of BaP with the TiO2 NP bound AHR-complex (score 4710), and observed that BaP showed strong adsorption on TiO2 NP itself, and not at its original binding site (at AHR). TiO2 NPs thereby prevent the entry of BaP in to the cell via AHR and hence protect cells against the deleterious effects induced by BaP. PMID:25215666

  12. Uniform TiO2 nanoparticles induce apoptosis in epithelial cell lines in a size-dependent manner.

    Science.gov (United States)

    Sun, Qingqing; Ishii, Takayuki; Kanehira, Koki; Sato, Takeshi; Taniguchi, Akiyoshi

    2017-05-02

    The size of titanium dioxide (TiO 2 ) nanoparticles is a vital parameter that determines their cytotoxicity. However, most reported studies have employed irregular shapes and sizes of TiO 2 nanoparticles, as it is difficult to produce nanoparticles of suitable sizes for research. We produced good model TiO 2 nanoparticles of uniform shape and size for use in studying their cytotoxicity. In this work, spherical, uniform polyethylene glycol-modified TiO 2 (TiO 2 -PEG) nanoparticles of differing sizes (100, 200, and 300 nm) were prepared using the sol-gel method. A size-dependent decrease in cell viability was observed with increasing nanoparticle size. Furthermore, apoptosis was found to be positively associated with nanoparticle size, as evidenced by an increase in caspase-3 activity with increasing nanoparticle size. Larger nanoparticles exhibited higher cellular uptake, suggesting that larger nanoparticles more strongly induce apoptosis. In addition, the cellular uptake of different sizes of nanoparticles was energy dependent, suggesting that there are size-dependent uptake pathways. We found that 100 and 200 nm (but not 300 nm) nanoparticles were taken up via clathrin-mediated endocytosis. These results utilizing uniform nanoparticles suggest that the size-dependent cytotoxicity of nanoparticles involves active cellular uptake, caspase-3 activation, and apoptosis in the epithelial cell line (NCI-H292). These findings will hopefully aid in the future design and safe use of nanoparticles.

  13. Titanium dioxide encapsulation of supported Ag nanoparticles on the porous silica bead for increased photocatalytic activity

    International Nuclear Information System (INIS)

    Liu, Hui; Deng, Lu; Sun, Chaochao; Li, Junqi; Zhu, Zhenfeng

    2015-01-01

    Graphical abstract: - Highlights: • A novel Ag-loading and TiO 2 -coating technique was used to prepare samples. • The photocatalytic activity of the product was evaluated by removing of Rh B. • The as-synthesized samples showed an excellent photocatalytic activity. - Abstract: A new synthetic strategy has been developed to encapsulate Ag nanoparticles in heterogeneous catalysts to prevent their dropping and sintering. Ag nanoparticles with diameters about 5–10 nm were first supported on the porous silica bead. These were then covered with a fresh layer of titanium dioxide with the thickness about 5 nm. SEM and TEM images were used to confirm the success of each synthesis step, and the photocatalytic activity of the as-synthesized samples was evaluated by photocatalytic decolorization of Rhodamine B (Rh B) aqueous solution at ambient temperature under both UV and visible light irradiation. The resulting titanium dioxide encapsulated Ag nanoparticles exhibited an enhanced photocatalytic activity under both UV and visible light irradiation, this can be attributed to effective charge separation and light harvesting of the plasmonic silver nanoparticles decoration, even the reducing of the exciton recombination rate caused by the small grain size of anatase TiO 2 nanocrystals

  14. Reduced graphene oxide supported gold nanoparticles for electrocatalytic reduction of carbon dioxide

    Science.gov (United States)

    Saquib, Mohammad; Halder, Aditi

    2018-02-01

    Electrochemical reduction of carbon dioxide is one of the methods which have the capability to recycle CO2 into valuable products for energy and industrial applications. This research article describes about a new electrocatalyst "reduced graphene oxide supported gold nanoparticles" for selective electrochemical conversion of carbon dioxide to carbon monoxide. The main aim for conversion of CO2 to CO lies in the fact that the latter is an important component of syn gas (a mixture of hydrogen and carbon monoxide), which is then converted into liquid fuel via well-known industrial process called Fischer-Tropsch process. In this work, we have synthesized different composites of the gold nanoparticles supported on defective reduced graphene oxide to evaluate the catalytic activity of reduced graphene oxide (RGO)-supported gold nanoparticles and the role of defective RGO support towards the electrochemical reduction of CO2. Electrochemical and impedance measurements demonstrate that higher concentration of gold nanoparticles on the graphene support led to remarkable decrease in the onset potential of 240 mV and increase in the current density for CO2 reduction. Lower impedance and Tafel slope values also clearly support our findings for the better performance of RGOAu than bare Au for CO2 reduction.

  15. Targeting thyroid cancer with acid-triggered release of doxorubicin from silicon dioxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Li SJ

    2017-08-01

    Full Text Available Shijie Li,1 Daqi Zhang,1 Shihou Sheng,2 Hui Sun1 1Department of Thyroid Surgery, 2Department of Gastrointestinal Colorectal and Anal Surgery, China–Japan Union Hospital of Jilin University, Chang Chun, People’s Republic of China Abstract: Currently, therapy for thyroid cancer mainly involves surgery and radioiodine therapy. However, chemotherapy can be used in advanced and aggressive thyroid cancer that cannot be treated by other options. Nevertheless, a major obstacle to the successful treatment of thyroid cancer is the delivery of drugs to the thyroid gland. Here, we present an example of the construction of silicon dioxide nanoparticles with thyroid–stimulating-hormone receptor-targeting ligand that can specifically target the thyroid cancer. Doxorubicin nanoparticles can be triggered by acid to release the drug payload for cancer therapy. These nanoparticles shrink the tumor size in vivo with less toxic side effects. This research paves the way toward effective chemotherapy for thyroid cancer. Keywords: thyroid cancer, silicon dioxide nanoparticle, doxorubicin, acid-triggered release

  16. Acute and subchronic toxicity analysis of surface modified paclitaxel attached hydroxyapatite and titanium dioxide nanoparticles

    Science.gov (United States)

    Venkatasubbu, Gopinath Devanand; Ramasamy, S; Gaddam, Pramod Reddy; Kumar, J

    2015-01-01

    Nanoparticles are widely used for targeted drug delivery applications. Surface modification with appropriate polymer and ligands is carried out to target the drug to the affected area. Toxicity analysis is carried out to evaluate the safety of the surface modified nanoparticles. In this study, paclitaxel attached, folic acid functionalized, polyethylene glycol modified hydroxyapatite and titanium dioxide nanoparticles were used for targeted drug delivery system. The toxicological behavior of the system was studied in vivo in rats and mice. Acute and subchronic studies were carried out. Biochemical, hematological, and histopathological analysis was also done. There were no significant alterations in the biochemical parameters at a low dosage. There was a small change in alkaline phosphatase (ALP) level at a high dosage. The results indicate a safe toxicological profile. PMID:26491315

  17. The effect of electrolytes on the aggregation kinetics of titanium dioxide nanoparticle aggregates

    International Nuclear Information System (INIS)

    Shih Yanghsin; Zhuang Chengming; Tso Chihping; Lin Chenghan

    2012-01-01

    Metal oxide nanoparticles (NPs) are receiving increasing attention due to their increased industrial production and potential hazardous effect. The process of aggregation plays a key role in the fate of NPs in the environment and the resultant health risk. The aggregation of commercial titanium dioxide NP powder (25 nm) was investigated with various environmentally relevant solution chemistries containing different concentrations of monovalent (Na + , K + ) and divalent (Ca 2+ ) electrolytes. Titanium dioxide particle size increased with the increase in ion concentration. The stability of titanium dioxide also depended on the ionic composition. Titanium dioxide aggregated to a higher degree in the presence of divalent cations than monovalent ones. The attachment efficiency of NPs was constructed through aggregation kinetics data, from which the critical coagulation concentrations for the various electrolytes are determined (80, 19, and 1 meq/L for Na + , K + , and Ca 2+ , respectively). Our results suggest that titanium dioxide NP powders are relatively unstable in water and could easily be removed by adding multivalent cations so hazardous potentials decrease in aquatic environment.

  18. Multiple-diffusion flame synthesis of pure anatase and carbon-coated titanium dioxide nanoparticles

    KAUST Repository

    Memon, Nasir

    2013-09-01

    A multi-element diffusion flame burner (MEDB) is useful in the study of flame synthesis of nanomaterials. Here, the growth of pure anatase and carbon-coated titanium dioxide (TiO2) using an MEDB is demonstrated. Hydrogen (H2), oxygen (O2), and argon (Ar) are utilized to establish the flame, whereas titanium tetraisopropoxide is used as the precursor for TiO2. The nanoparticles are characterized using high-resolution transmission electron microscopy, with elemental mapping (of C, O, and Ti), X-ray diffraction, Raman spectroscopy, and thermogravimetric analysis. The growth of pure anatase TiO2 nanoparticles occurs when Ar and H2 are used as the precursor carrier gas, while the growth of carbon-coated nanoparticles ensues when Ar and ethylene (C2H4) are used as the precursor carrier gas. A uniform coating of 3-5nm of carbon is observed around TiO2 particles. The growth of highly crystalline TiO2 nanoparticles is dependent on the gas flow rate of the precursor carrier and amorphous particles are observed at high flow rates. Carbon coating occurs only on crystalline nanoparticles, suggesting a possible growth mechanism of carbon-coated TiO2 nanoparticles. © 2013 The Combustion Institute.

  19. Shape-induced anisotropy in antiferromagnetic nanoparticles

    International Nuclear Information System (INIS)

    Gomonay, O.; Kondovych, S.; Loktev, V.

    2014-01-01

    High fraction of the surface atoms considerably enhances the influence of size and shape on the magnetic and electronic properties of nanoparticles. Shape effects in ferromagnetic nanoparticles are well understood and allow us to set and control the parameters of a sample that affect its magnetic anisotropy during production. In the present paper we study the shape effects in the other widely used magnetic materials – antiferromagnets, – which possess vanishingly small or zero macroscopic magnetization. We take into account the difference between the surface and bulk magnetic anisotropy of a nanoparticle and show that the effective magnetic anisotropy depends on the particle shape and crystallographic orientation of its faces. The corresponding shape-induced contribution to the magnetic anisotropy energy is proportional to the particle volume, depends on magnetostriction, and can cause formation of equilibrium domain structure. Crystallographic orientation of the nanoparticle surface determines the type of domain structure. The proposed model allows us to predict the magnetic properties of antiferromagnetic nanoparticles depending on their shape and treatment. - Highlights: • We demonstrate that the shape effects in antiferromagnetic nanoparticles stem from the difference of surface and bulk magnetic properties combined with strong magnetoelastic coupling. • We predict shape-induced anisotropy in antiferromagnetic particles with large aspect ratio. • We predict different types of domain structures depending on the orientation of the particle faces

  20. Size-mediated cytotoxicity of nanocrystalline titanium dioxide, pure and zinc-doped hydroxyapatite nanoparticles in human hepatoma cells

    International Nuclear Information System (INIS)

    Devanand Venkatasubbu, G.; Ramasamy, S.; Avadhani, G. S.; Palanikumar, L.; Kumar, J.

    2012-01-01

    Nanoparticles are highly used in biological applications including nanomedicine. In this present study, the interaction of HepG2 hepatocellular carcinoma cells (HCC) with hydroxyapatite (HAp), zinc-doped hydroxyapatite, and titanium dioxide (TiO 2 ) nanoparticles were investigated. Hydroxyapatite, zinc-doped hydroxyapatite and titanium dioxide nanoparticles were prepared by wet precipitation method. They were subjected to isochronal annealing at different temperatures. Particle morphology and size distribution were characterized by X-ray diffraction and transmission electron microscope. The nanoparticles were co-cultured with HepG2 cells. MTT assay was employed to evaluate the proliferation of tumor cells. The DNA damaging effect of HAp, Zn-doped HAp, and TiO 2 nanoparticles in human hepatoma cells (HepG2) were evaluated using DNA fragmentation studies. The results showed that in HepG2 cells, the anti-tumor activity strongly depend on the size of nanoparticles in HCC cells. Cell cycle arrest analysis for HAp, zinc-doped HAp, and TiO 2 nanoparticles revealed the influence of HAp, zinc-doped HAp, and titanium dioxide nanoparticles on the apoptosis of HepG2 cells. The results imply that the novel nano nature effect plays an important role in the biomedicinal application of nanoparticles.

  1. Electron Microscopy Characterization of Vanadium Dioxide Thin Films and Nanoparticles

    Science.gov (United States)

    Rivera, Felipe

    Vanadium dioxide (VO_2) is a material of particular interest due to its exhibited metal to insulator phase transition at 68°C that is accompanied by an abrupt and significant change in its electronic and optical properties. Since this material can exhibit a reversible drop in resistivity of up to five orders of magnitude and a reversible drop in infrared optical transmission of up to 80%, this material holds promise in several technological applications. Solid phase crystallization of VO_2 thin films was obtained by a post-deposition annealing process of a VO_{x,x approx 2} amorphous film sputtered on an amorphous silicon dioxide (SiO_2) layer. Scanning electron microscopy (SEM) and electron-backscattered diffraction (EBSD) were utilized to study the morphology of the solid phase crystallization that resulted from this post-deposition annealing process. The annealing parameters ranged in temperature from 300°C up to 1000°C and in time from 5 minutes up to 12 hours. Depending on the annealing parameters, EBSD showed that this process yielded polycrystalline vanadium dioxide thin films, semi-continuous thin films, and films of isolated single-crystal particles. In addition to these films on SiO_2, other VO_2 thin films were deposited onto a-, c-, and r-cuts of sapphire and on TiO_2(001) heated single-crystal substrates by pulsed-laser deposition (PLD). The temperature of the substrates was kept at ˜500°C during deposition. EBSD maps and orientation imaging microscopy were used to study the epitaxy and orientation of the VO_2 grains deposited on the single crystal substrates, as well as on the amorphous SiO_2 layer. The EBSD/OIM results showed that: 1) For all the sapphire substrates analyzed, there is a predominant family of crystallographic relationships wherein the rutile VO_2{001} planes tend to lie parallel to the sapphire's {10-10} and the rutile VO_2{100} planes lie parallel to the sapphire's {1-210} and {0001}. Furthermore, while this family of

  2. Gas-phase Crystallization of Titanium Dioxide Nanoparticles

    International Nuclear Information System (INIS)

    Ahonen, P.P.; Moisala, A.; Tapper, U.; Brown, D.P.; Jokiniemi, J.K.; Kauppinen, E.I.

    2002-01-01

    We have investigated the development of crystal morphology and phase in ultrafine titanium dioxide particles. The particles were produced by a droplet-to-particle method starting from propanolic titanium tetraisopropoxide solution, and calcined in a vertical aerosol reactor in air. Mobility size classified 40-nm diameter particles were conveyed to the aerosol reactor to investigate particle size changes at 20-1200 deg. C with 5-1-s residence time. In addition, polydisperse particles were used to study morphology and phase formation by electron microscopy. According to differential mobility analysis, the particle diameter was reduced to 21-23-nm at 600 deg. C and above. Precursor decomposition occurred between 20 deg. C and 500 deg. C. The increased mobility particle size at 700 deg. C and above was observed to coincide with irregular particles at 700 deg. C and 800 deg. C and faceted particles between 900 deg. C and 1200 deg. C, according to transmission electron microscopy. The faceted anatase particles were observed to approach a minimized surface energy by forming {101} and {001} crystallographic surfaces. Anatase phase was observed at 500-1200 deg. C and above 600 deg. C the particles were single crystals. Indications of minor rutile formation were observed at 1200 deg. C. The relatively stable anatase phase vs. temperature is attributed to the defect free structure of the observed particles and a lack of crystal-crystal attachment points

  3. The effect of titanium dioxide nanoparticles on antioxidant gene expression in tilapia ( Oreochromis niloticus)

    Science.gov (United States)

    Varela-Valencia, Ruth; Gómez-Ortiz, Nikte; Oskam, Gerko; de Coss, Romeo; Rubio-Piña, Jorge; del Río-García, Marcela; Albores-Medina, Arnulfo; Zapata-Perez, Omar

    2014-04-01

    The reactivity of nanoparticles (NPs) in biological systems is well recognized, but there are huge gaps in our understanding of NP toxicity in fish, despite a number of recent ecotoxicity studies. Therefore, the aim of this research was to evaluate the effect of titanium dioxide NPs (TiO2-NPs) on antioxidant gene expression in the tilapia, Oreochromis niloticus. First, different sizes, shapes, and phases of TiO2-NPs were synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS). Fish were injected intraperitoneally with different concentrations (0.1, 1.0, 10.0 mg/L), sizes (7, 14, and 21 nm), and phases (anatase and rutile) of TiO2-NPs, and sacrificed 3, 6, 12, and 24 h after injection, when their livers were removed. Total RNA was extracted, and expression of the catalase ( CAT), glutathione- S-transferase ( GST), and superoxide dismutase ( SOD) genes was assessed by real-time polymerase chain reaction (RT-PCR). The results showed that injection of 1.0 mg/L TiO2-NPs induced an initial mild increase in CAT, GST, and SOD gene expression in tilapia, after which transcript levels decreased. Fish injected with 7 and 14 nm TiO2-NPs showed an increase in antioxidant transcript levels 6 h after treatment. Finally, the rutile form generated stronger induction of the GST gene than anatase TiO2-NPs during the first 6 h after injection, which suggests that exposure to rutile causes higher levels of reactive oxygen species to be produced.

  4. Titanium Dioxide Nanoparticle Penetration into the Skin and Effects on HaCaT Cells

    Directory of Open Access Journals (Sweden)

    Matteo Crosera

    2015-08-01

    Full Text Available Titanium dioxide nanoparticles (TiO2NPs suspensions (concentration 1.0 g/L in synthetic sweat solution were applied on Franz cells for 24 h using intact and needle-abraded human skin. Titanium content into skin and receiving phases was determined. Cytotoxicity (MTT, AlamarBlue® and propidium iodide, PI, uptake assays was evaluated on HaCat keratinocytes after 24 h, 48 h, and seven days of exposure. After 24 h of exposure, no titanium was detectable in receiving solutions for both intact and damaged skin. Titanium was found in the epidermal layer after 24 h of exposure (0.47 ± 0.33 μg/cm2 while in the dermal layer, the concentration was below the limit of detection. Damaged skin, in its whole, has shown a similar concentration (0.53 ± 0.26 μg/cm2. Cytotoxicity studies on HaCaT cells demonstrated that TiO2NPs induced cytotoxic effects only at very high concentrations, reducing cell viability after seven days of exposure with EC50s of 8.8 × 10−4 M (MTT assay, 3.8 × 10−5 M (AlamarBlue® assay, and 7.6 × 10−4 M (PI uptake, index of a necrotic cell death. Our study demonstrated that TiO2NPs cannot permeate intact and damaged skin and can be found only in the stratum corneum and epidermis. Moreover, the low cytotoxic effect observed on human HaCaT keratinocytes suggests that these nano-compounds have a potential toxic effect at the skin level only after long-term exposure.

  5. Biological effect of food additive titanium dioxide nanoparticles on intestine: an in vitro study.

    Science.gov (United States)

    Song, Zheng-Mei; Chen, Ni; Liu, Jia-Hui; Tang, Huan; Deng, Xiaoyong; Xi, Wen-Song; Han, Kai; Cao, Aoneng; Liu, Yuanfang; Wang, Haifang

    2015-10-01

    Titanium dioxide nanoparticles (TiO2 NPs) are widely found in food-related consumer products. Understanding the effect of TiO2 NPs on the intestinal barrier and absorption is essential and vital for the safety assessment of orally administrated TiO2 NPs. In this study, the cytotoxicity and translocation of two native TiO2 NPs, and these two TiO2 NPs pretreated with the digestion simulation fluid or bovine serum albumin were investigated in undifferentiated Caco-2 cells, differentiated Caco-2 cells and Caco-2 monolayer. TiO2 NPs with a concentration less than 200 µg ml(-1) did not induce any toxicity in differentiated cells and Caco-2 monolayer after 24 h exposure. However, TiO2 NPs pretreated with digestion simulation fluids at 200 µg ml(-1) inhibited the growth of undifferentiated Caco-2 cells. Undifferentiated Caco-2 cells swallowed native TiO2 NPs easily, but not pretreated NPs, implying the protein coating on NPs impeded the cellular uptake. Compared with undifferentiated cells, differentiated ones possessed much lower uptake ability of these TiO2 NPs. Similarly, the traverse of TiO2 NPs through the Caco-2 monolayer was also negligible. Therefore, we infer the possibility of TiO2 NPs traversing through the intestine of animal or human after oral intake is quite low. This study provides valuable information for the risk assessment of TiO2 NPs in food. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Effect of titanium dioxide nanoparticles on the bioavailability, metabolism, and toxicity of pentachlorophenol in zebrafish larvae

    International Nuclear Information System (INIS)

    Fang, Qi; Shi, Xiongjie; Zhang, Liping; Wang, Qiangwei; Wang, Xianfeng; Guo, Yongyong; Zhou, Bingsheng

    2015-01-01

    Highlights: • Effects of n-TiO 2 on toxicity of PCP in zebrafish larvae were investigated. • Co-exposure n-TiO 2 enhanced metabolism of PCP to tetrachlorohydroquinone in larvae. • Co-exposure n-TiO 2 increased oxidative damage and developmental toxicity in larvae. • NPs may influence toxicity of associated organic pollutants in the aquatic environment. - Abstract: This study investigated the influence of titanium dioxide nanoparticles (n-TiO 2 ) on the bioavailability, metabolism, and toxicity of pentachlorophenol (PCP) in fish. Zebrafish (Danio rerio) embryos or larvae (2-h post-fertilization) were exposed to PCP (0, 3, 10, and 30 μg/L) alone or in combination with n-TiO 2 (0.1 mg/L) until 6 days post-fertilization. Results showed that n-TiO 2 treatment alone did not induce lipid peroxidation, DNA damage, as well as the generation of reactive oxygen species (ROS) in the larvae. As compared with PCP treatment, the co-exposure of PCP and n-TiO 2 enhanced the induction of ROS generation, eventually leading to lipid peroxidation and DNA damage. The nuclear factor erythroid 2-related factor 2 gene transcriptions were significantly upregulated in both PCP treatment alone and in combination with n-TiO 2 . Chemical analysis and histological examination showed that n-TiO 2 adsorb PCP, and n-TiO 2 are taken up by developing zebrafish larvae; however, PCP content was not enhanced in the presence of n-TiO 2 , but the metabolism of PCP to tetrachlorohydroquinone was enhanced in larvae. The results indicate that n-TiO 2 enhanced the metabolism of PCP and caused oxidative damage and developmental toxicity, suggesting that NPs can influence the fate and toxicity of associated organic pollutants in the aquatic environment

  7. Effect of titanium dioxide nanoparticles on the bioavailability, metabolism, and toxicity of pentachlorophenol in zebrafish larvae

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Qi [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Shi, Xiongjie [College of Life Sciences, Wuhan University, Wuhan 430072 (China); Zhang, Liping [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Wang, Qiangwei; Wang, Xianfeng [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Guo, Yongyong [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Zhou, Bingsheng, E-mail: bszhou@ihb.ac.cn [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

    2015-02-11

    Highlights: • Effects of n-TiO{sub 2} on toxicity of PCP in zebrafish larvae were investigated. • Co-exposure n-TiO{sub 2} enhanced metabolism of PCP to tetrachlorohydroquinone in larvae. • Co-exposure n-TiO{sub 2} increased oxidative damage and developmental toxicity in larvae. • NPs may influence toxicity of associated organic pollutants in the aquatic environment. - Abstract: This study investigated the influence of titanium dioxide nanoparticles (n-TiO{sub 2}) on the bioavailability, metabolism, and toxicity of pentachlorophenol (PCP) in fish. Zebrafish (Danio rerio) embryos or larvae (2-h post-fertilization) were exposed to PCP (0, 3, 10, and 30 μg/L) alone or in combination with n-TiO{sub 2} (0.1 mg/L) until 6 days post-fertilization. Results showed that n-TiO{sub 2} treatment alone did not induce lipid peroxidation, DNA damage, as well as the generation of reactive oxygen species (ROS) in the larvae. As compared with PCP treatment, the co-exposure of PCP and n-TiO{sub 2} enhanced the induction of ROS generation, eventually leading to lipid peroxidation and DNA damage. The nuclear factor erythroid 2-related factor 2 gene transcriptions were significantly upregulated in both PCP treatment alone and in combination with n-TiO{sub 2}. Chemical analysis and histological examination showed that n-TiO{sub 2} adsorb PCP, and n-TiO{sub 2} are taken up by developing zebrafish larvae; however, PCP content was not enhanced in the presence of n-TiO{sub 2}, but the metabolism of PCP to tetrachlorohydroquinone was enhanced in larvae. The results indicate that n-TiO{sub 2} enhanced the metabolism of PCP and caused oxidative damage and developmental toxicity, suggesting that NPs can influence the fate and toxicity of associated organic pollutants in the aquatic environment.

  8. Titanium Dioxide Nanoparticle Penetration into the Skin and Effects on HaCaT Cells.

    Science.gov (United States)

    Crosera, Matteo; Prodi, Andrea; Mauro, Marcella; Pelin, Marco; Florio, Chiara; Bellomo, Francesca; Adami, Gianpiero; Apostoli, Pietro; De Palma, Giuseppe; Bovenzi, Massimo; Campanini, Marco; Filon, Francesca Larese

    2015-08-07

    Titanium dioxide nanoparticles (TiO2NPs) suspensions (concentration 1.0 g/L) in synthetic sweat solution were applied on Franz cells for 24 h using intact and needle-abraded human skin. Titanium content into skin and receiving phases was determined. Cytotoxicity (MTT, AlamarBlue(®) and propidium iodide, PI, uptake assays) was evaluated on HaCat keratinocytes after 24 h, 48 h, and seven days of exposure. After 24 h of exposure, no titanium was detectable in receiving solutions for both intact and damaged skin. Titanium was found in the epidermal layer after 24 h of exposure (0.47 ± 0.33 μg/cm(2)) while in the dermal layer, the concentration was below the limit of detection. Damaged skin, in its whole, has shown a similar concentration (0.53 ± 0.26 μg/cm(2)). Cytotoxicity studies on HaCaT cells demonstrated that TiO2NPs induced cytotoxic effects only at very high concentrations, reducing cell viability after seven days of exposure with EC50s of 8.8 × 10(-4) M (MTT assay), 3.8 × 10(-5) M (AlamarBlue(®) assay), and 7.6 × 10(-4) M (PI uptake, index of a necrotic cell death). Our study demonstrated that TiO2NPs cannot permeate intact and damaged skin and can be found only in the stratum corneum and epidermis. Moreover, the low cytotoxic effect observed on human HaCaT keratinocytes suggests that these nano-compounds have a potential toxic effect at the skin level only after long-term exposure.

  9. Microglial cells (BV-2) internalize titanium dioxide (TiO2) nanoparticles: toxicity and cellular responses.

    Science.gov (United States)

    Rihane, Naima; Nury, Thomas; M'rad, Imen; El Mir, Lassaad; Sakly, Mohsen; Amara, Salem; Lizard, Gérard

    2016-05-01

    Because of their whitening and photocatalytic effects, titanium dioxide nanoparticles (TiO2-NPs) are widely used in daily life. These NPs can be found in paints, plastics, papers, sunscreens, foods, medicines (pills), toothpastes, and cosmetics. However, the biological effect of TiO2-NPs on the human body, especially on the central nervous system, is still unclear. Many studies have demonstrated that the brain is one of the target organs in acute or chronic TiO2-NPs toxicity. The present study aimed to investigate the effect of TiO2-NPs at different concentrations (0.1 to 200 μg/mL) on murine microglial cells (BV-2) to assess their activity on cell growth and viability, as well as their neurotoxicity. Different parameters were measured: cell viability, cell proliferation and DNA content (SubG1 peak), mitochondrial depolarization, overproduction of reactive oxygen species (especially superoxide anions), and ultrastructural changes. Results showed that TiO2-NPs induced some cytotoxic effects with a slight inhibition of cell growth. Thus, at high concentrations, TiO2-NPs were not only able to inhibit cell adhesion but also enhanced cytoplasmic membrane permeability to propidium iodide associated with a loss of mitochondrial transmembrane potential and an overproduction of superoxide anions. No induction of apoptosis based on the presence of a SubG1 peak was detected. The microscopic observations also indicated that small groups of nanosized particles and micron-sized aggregates were engulfed by the BV-2 cells and sequestered as intracytoplasmic aggregates after 24-h exposure to TiO2-NPs. Altogether, our data show that the accumulation TiO2-NPs in microglial BV-2 cells favors mitochondrial dysfunctions and oxidative stress.

  10. Titanium dioxide induced inflammation in the small intestine

    Science.gov (United States)

    Nogueira, Carolina Maciel; de Azevedo, Walter Mendes; Dagli, Maria Lucia Zaidan; Toma, Sérgio Hiroshi; Leite, André Zonetti de Arruda; Lordello, Maria Laura; Nishitokukado, Iêda; Ortiz-Agostinho, Carmen Lúcia; Duarte, Maria Irma Seixas; Ferreira, Marcelo Alves; Sipahi, Aytan Miranda

    2012-01-01

    AIM: To investigate the effects of titanium dioxide (TiO2) nanoparticles (NPTiO2) and microparticles (MPTiO2) on the inflammatory response in the small intestine of mice. METHODS: Bl 57/6 male mice received distilled water suspensions containing TiO2 (100 mg/kg body weight) as NPTiO2 (66 nm), or MPTiO2 (260 nm) by gavage for 10 d, once a day; the control group received only distilled water. At the end of the treatment the duodenum, jejunum and ileum were extracted for assessment of cytokines, inflammatory cells and titanium content. The cytokines interleukin (IL)-1b, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-17, IL-23, tumor necrosis factor-α (TNF-α), intracellular interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) were evaluated by enzyme-linked immunosorbent assay in segments of jejunum and ileum (mucosa and underlying muscular tissue). CD4+ and CD8+ T cells, natural killer cells, and dendritic cells were evaluated in duodenum, jejunum and ileum samples fixed in 10% formalin by immunohistochemistry. The titanium content was determined by inductively coupled plasma atomic emission spectrometry. RESULTS: We found increased levels of T CD4+ cells (cells/mm2) in duodenum: NP 1240 ± 139.4, MP 1070 ± 154.7 vs 458 ± 50.39 (P < 0.01); jejunum: NP 908.4 ± 130.3, MP 813.8 ± 103.8 vs 526.6 ± 61.43 (P < 0.05); and ileum: NP 818.60 ± 123.0, MP 640.1 ± 32.75 vs 466.9 ± 22.4 (P < 0.05). In comparison to the control group, the groups receiving TiO2 showed a statistically significant increase in the levels of the inflammatory cytokines IL-12, IL-4, IL-23, TNF-α, IFN-γ and TGF-β. The cytokine production was more pronounced in the ileum (mean ± SE): IL-12: NP 33.98 ± 11.76, MP 74.11 ± 25.65 vs 19.06 ± 3.92 (P < 0.05); IL-4: NP 17.36 ± 9.96, MP 22.94 ± 7.47 vs 2.19 ± 0.65 (P < 0.05); IL-23: NP 157.20 ± 75.80, MP 134.50 ± 38.31 vs 22.34 ± 5.81 (P < 0.05); TNFα: NP 3.71 ± 1.33, MP 5.44 ± 1.67 vs 0.99 ± 019 (P < 0.05); IFNγ: NP 15.85 ± 9

  11. Titanium dioxide and zinc oxide nanoparticles in sunscreens: focus on their safety and effectiveness

    Directory of Open Access Journals (Sweden)

    Smijs TG

    2011-10-01

    Full Text Available Threes G Smijs1–3, Stanislav Pavel4 1Faculty of Science, Open University in The Netherlands, Rotterdam, The Netherlands; 2University of Leiden, Leiden Amsterdam Center for Drug Research, Leiden, The Netherlands; 3Erasmus MC, Center for Optical Diagnostics and Therapy, Rotterdam, The Netherlands; 4Charles University, Faculty of Medicine, Department of Dermatology, Pilsen, Czech Republic Abstract: Sunscreens are used to provide protection against adverse effects of ultraviolet (UVB (290–320 nm and UVA (320–400 nm radiation. According to the United States Food and Drug Administration, the protection factor against UVA should be at least one-third of the overall sun protection factor. Titanium dioxide (TiO2 and zinc oxide (ZnO minerals are frequently employed in sunscreens as inorganic physical sun blockers. As TiO2 is more effective in UVB and ZnO in the UVA range, the combination of these particles assures a broad-band UV protection. However, to solve the cosmetic drawback of these opaque sunscreens, microsized TiO2 and ZnO have been increasingly replaced by TiO2 and ZnO nanoparticles (NPs (<100 nm. This review focuses on significant effects on the UV attenuation of sunscreens when microsized TiO2 and ZnO particles are replaced by NPs and evaluates physicochemical aspects that affect effectiveness and safety of NP sunscreens. With the use of TiO2 and ZnO NPs, the undesired opaqueness disappears but the required balance between UVA and UVB protection can be altered. Utilization of mixtures of micro- and nanosized ZnO dispersions and nanosized TiO2 particles may improve this situation. Skin exposure to NP-containing sunscreens leads to incorporation of TiO2 and ZnO NPs in the stratum corneum, which can alter specific NP attenuation properties due to particle–particle, particle–skin, and skin–particle–light physicochemical interactions. Both sunscreen NPs induce (photocyto- and genotoxicity and have been sporadically observed in viable

  12. Biosynthesis of titanium dioxide nanoparticles using a probiotic from coal fly ash effluent

    International Nuclear Information System (INIS)

    Babitha, S; Korrapati, Purna Sai

    2013-01-01

    Graphical abstract: - Highlights: • Metal resistant probiotic species was isolated from coal fly ash effluent site. • Uniform sized anatase form of TiO 2 nanoparticles were synthesized using Propionibacterium jensenii. • Diffraction patterns confirmed the anatase – TiO 2 NPs with average size 2 nanoparticle incorporated wound dressing exhibits better wound healing. - Abstract: The synthesis of titanium dioxide nanoparticle (TiO 2 NP) has gained importance in the recent years owing to its wide range of potential biological applications. The present study demonstrates the synthesis of TiO 2 NPs by a metal resistant bacterium isolated from the coal fly ash effluent. This bacterial strain was identified on the basis of morphology and 16s rDNA gene sequence [KC545833]. The physico-chemical characterization of the synthesized nanoparticles is completely elucidated by energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (TEM, SEM). The crystalline nature of the nanoparticles was confirmed by X-RD pattern. Further, cell viability and haemolytic assays confirmed the biocompatible and non toxic nature of the NPs. The TiO 2 NPs was found to enhance the collagen stabilization and thereby enabling the preparation of collagen based biological wound dressing. The paper essentially provides scope for an easy bioprocess for the synthesis of TiO 2 NPs from the metal oxide enriched effluent sample for future biological applications

  13. Biosynthesis of titanium dioxide nanoparticles using a probiotic from coal fly ash effluent

    Energy Technology Data Exchange (ETDEWEB)

    Babitha, S; Korrapati, Purna Sai, E-mail: purnasaik.clri@gmail.com

    2013-11-15

    Graphical abstract: - Highlights: • Metal resistant probiotic species was isolated from coal fly ash effluent site. • Uniform sized anatase form of TiO{sub 2} nanoparticles were synthesized using Propionibacterium jensenii. • Diffraction patterns confirmed the anatase – TiO{sub 2} NPs with average size <80 nm. • TiO{sub 2} nanoparticle incorporated wound dressing exhibits better wound healing. - Abstract: The synthesis of titanium dioxide nanoparticle (TiO{sub 2} NP) has gained importance in the recent years owing to its wide range of potential biological applications. The present study demonstrates the synthesis of TiO{sub 2} NPs by a metal resistant bacterium isolated from the coal fly ash effluent. This bacterial strain was identified on the basis of morphology and 16s rDNA gene sequence [KC545833]. The physico-chemical characterization of the synthesized nanoparticles is completely elucidated by energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (TEM, SEM). The crystalline nature of the nanoparticles was confirmed by X-RD pattern. Further, cell viability and haemolytic assays confirmed the biocompatible and non toxic nature of the NPs. The TiO{sub 2} NPs was found to enhance the collagen stabilization and thereby enabling the preparation of collagen based biological wound dressing. The paper essentially provides scope for an easy bioprocess for the synthesis of TiO{sub 2} NPs from the metal oxide enriched effluent sample for future biological applications.

  14. Potassium iodate assisted synthesis of titanium dioxide nanoparticles with superior water-dispersibility.

    Science.gov (United States)

    Wang, Yawen; Duo, Fangfang; Peng, Shiqi; Jia, Falong; Fan, Caimei

    2014-09-15

    In this paper, we report a novel polyol process to synthesize highly water-dispersible anatase titanium dioxide (TiO2) nanoparticles (∼5 nm) by the introduction of inorganic oxidizing agent--KIO3. The obtained TiO2 nanoparticles are well dispersible in water at pH≥5.0 and the resulting aqueous dispersion remains stable over months. The superior water-dispersibility of as-formed TiO2 is ascribed to the electrostatic repulsion from carboxylic acid group modified on TiO2 nanoparticles, which is the oxidation product of solvent diethylene glycol (DEG) by KIO3. Based on the characterization results, the formation processes of water-dispersibility TiO2 nanoparticles are proposed. Meanwhile, the synthesized TiO2 nanoparticles are found to be doped by iodine and exhibit excellent photocatalytic activity on degradation of rhodamine-B (RhB) under visible-light irradiation. The further tests demonstrate that the O(2-) is the main active species during photodegradation of RhB. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Modified surface of titanium dioxide nanoparticles-based biosensor for DNA detection

    Science.gov (United States)

    Nadzirah, Sh.; Hashim, U.; Rusop, M.

    2018-05-01

    A new technique was used to develop a simple and selective picoammeter DNA biosensor for identification of E. coli O157:H7. This biosensor was fabricated from titanium dioxide nanoparticles that was synthesized by sol-gel method and spin-coated on silicon dioxide substrate via spinner. 3-Aminopropyl triethoxy silane (APTES) was used to modify the surface of TiO2. Simple surface modification approach has been applied; which is single dropping of APTES onto the TiO2 nanoparticles surface. Carboxyl modified probe DNA has been bind onto the surface of APTES/TiO2 without any amplifier element. Electrical signal has been used as the indicator to differentiate each step (surface modification of TiO2 and probe DNA immobilization). The I-V measurements indicate extremely low current (pico-ampere) flow through the device which is 2.8138E-10 A for pure TiO2 nanoparticles, 2.8124E-10 A after APTES modification and 3.5949E-10 A after probe DNA immobilization.

  16. Titanium Dioxide Nanoparticles in Food and Personal Care Products

    Science.gov (United States)

    Weir, Alex; Westerhoff, Paul; Fabricius, Lars

    2012-01-01

    Titanium dioxide is a common additive in many food, personal care, and other consumer products used by people, which after use can enter the sewage system, and subsequently enter the environment as treated effluent discharged to surface waters or biosolids applied to agricultural land, incinerated wastes, or landfill solids. This study quantifies the amount of titanium in common food products, derives estimates of human exposure to dietary (nano-) TiO2, and discusses the impact of the nanoscale fraction of TiO2 entering the environment. The foods with the highest content of TiO2 included candies, sweets and chewing gums. Among personal care products, toothpastes and select sunscreens contained 1% to >10% titanium by weight. While some other crèmes contained titanium, despite being colored white, most shampoos, deodorants, and shaving creams contained the lowest levels of titanium (TiO2 (E171) suggests that approximately 36% of the particles are less than 100 nm in at least one dimension and that it readily disperses in water as fairly stable colloids. However, filtration of water solubilized consumer products and personal care products indicated that less than 5% of the titanium was able to pass through 0.45 or 0.7 μm pores. Two white paints contained 110 μg Ti/mg while three sealants (i.e., prime coat paint) contained less titanium (25 to 40 μg Ti/mg). This research showed that while many white-colored products contained titanium, it was not a prerequisite. Although several of these product classes contained low amounts of titanium, their widespread use and disposal down the drain and eventually to WWTPs deserves attention. A Monte Carlo human exposure analysis to TiO2 through foods identified children as having the highest exposures because TiO2 content of sweets is higher than other food products, and that a typical exposure for a US adult may be on the order of 1 mg Ti per kilogram body weight per day. Thus, because of the millions of tons of titanium based

  17. Impact of silica dioxide nanoparticles on the morphology of internal organs in rats by oral supplementation

    Directory of Open Access Journals (Sweden)

    N.V. Zaitseva

    2016-12-01

    Full Text Available The object of the study was amorphous silica dioxide (SiO 2 , which is widely used as a food additive (E551, a subsidiary component in pharmaceutical preparations, perfumery and cosmetic products etc. In the specification of JECFA silica dioxide does not have information about the size of its particles, which allows the use of fine amorphous SiO 2 , obtained by gas phase hydrolysis of tetrachlorosilane as a food additive. This material, known as the "Aerosil", is characterized by the size of the specific surface area of 300–380 m 2 /g and the size of its relatively weakly agglomerated particles of 6–30 nm, i.e., it is a nanomaterial. In the biological model the morphological changes in organs and tissue systems on oral supplementation of nanoscale particles of silica dioxide were studied. Wistar male rats were given nanosized silica dioxide with specific surface area of 300 m 2 /g and primary nanoparticle size on the basis of data of electrical, atomic-powered microscopy, and dynamic light scattering in the range of 20–60 nm during 92 days. Light microscopic morphological examination of organs of rats showed a relatively mild inflammation in the structure of parenchymal organs (liver, kidney, not showing a certain dose-dependent nanoparticles. The most pronounced changes were in ileum morphology, consisting of a massive lymph macrophage and eosinophil infiltration of villi, without any apparent violation of their epithelial layer structure, which indirectly indicates the absence of violations of the barrier function of the intestinal epithelium. At the maximum dose of 100 mg/kg bw, the increased immune response was the most significant in the wall of the ileum. The results indicate the potential risks to human health when using SiO 2 having a specific surface area of 300 m 2 /g or higher in the composition of food products as a food additive.

  18. Algal testing of titanium dioxide nanoparticles - Testing considerations, inhibitory effects and modification of cadmium bioavailability

    DEFF Research Database (Denmark)

    Hartmann, Nanna Isabella Bloch; von der Kammer, F.; Hofmann, T.

    2010-01-01

    The ecotoxicity of three different sizes of titanium dioxide (TiO(2)) particles (primary particles sizes: 10, 30, and 300 nm) to the freshwater green alga Pseudokirchneriella subcapitata was investigated in this study. Algal growth inhibition was found for all three particle types...... surfaces. It is also believed that heteroaggregation, driven by algal exopolymeric exudates, is occurring and could influence the concentration-response relationship. The ecotoxicity of cadmium to algae was investigated both in the presence and absence of 2 mg/LTiO(2). The presence of TiO(2) in algal tests......(II) species, indicating a possible carrier effect, or combined toxic effect of TiO(2) nanoparticles and cadmium. These results emphasize the importance of systematic studies of nanoecotoxicological effects of different sizes of nanoparticles and underline the fact that, in addition to particle toxicity...

  19. Potential impact of inorganic nanoparticles on macronutrient digestion: titanium dioxide nanoparticles slightly reduce lipid digestion under simulated gastrointestinal conditions.

    Science.gov (United States)

    Li, Qian; Li, Ti; Liu, Chengmei; DeLoid, Glen; Pyrgiotakis, Georgios; Demokritou, Philip; Zhang, Ruojie; Xiao, Hang; McClements, David Julian

    Titanium dioxide (TiO 2 ) particles are used in some food products to alter their optical properties, such as whiteness or brightness. These additives typically contain a population of TiO 2 nanoparticles (d digestion through two physicochemical mechanisms: (i) a fraction of the lipase adsorbs to TiO 2 particle surfaces, thereby reducing the amount available to hydrolyze lipid droplets; (ii) some TiO 2 particles adsorb to the surfaces of lipid droplets, thereby reducing the lipid surface area exposed to lipase. The importance of these mechanisms was tested by passing protein-coated lipid droplets (2%, w/w) through the simulated GIT in the absence and presence of TiO 2 (0.5%, w/w) nanoparticles (18 nm) and fine particles (167 nm). Changes in particle characteristics (size, organization, and charge) and lipid digestion were then measured. Both TiO 2 nanoparticles and fine particles had little impact on the aggregation state and charge of the lipid droplets in the different GIT regions, as well as on the rate and extent of lipid digestion. This suggests that the theoretically predicted impact of particle size on lipid digestion was not seen in practice.

  20. Titanium dioxide nanoparticles modulate the toxicological response to cadmium in the gills of Mytilus galloprovincialis

    Energy Technology Data Exchange (ETDEWEB)

    Della Torre, Camilla [Department of Physical, Earth and Environmental Sciences, University of Siena (Italy); Balbi, Teresa [Department of Earth, Environmental and Life Sciences-DISTAV, University of Genoa (Italy); Grassi, Giacomo [Department of Physical, Earth and Environmental Sciences, University of Siena (Italy); Frenzilli, Giada; Bernardeschi, Margherita [Department of Clinical and Experimental Medicine, University of Pisa (Italy); Smerilli, Arianna [Department of Environmental, Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Seconda Università di Napoli, Caserta (Italy); Guidi, Patrizia [Department of Clinical and Experimental Medicine, University of Pisa (Italy); Canesi, Laura [Department of Earth, Environmental and Life Sciences-DISTAV, University of Genoa (Italy); Nigro, Marco [Department of Clinical and Experimental Medicine, University of Pisa (Italy); Monaci, Fabrizio [Department of Physical, Earth and Environmental Sciences, University of Siena (Italy); Scarcelli, Vittoria [Department of Clinical and Experimental Medicine, University of Pisa (Italy); Rocco, Lucia [Department of Environmental, Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Seconda Università di Napoli, Caserta (Italy); Focardi, Silvano [Department of Physical, Earth and Environmental Sciences, University of Siena (Italy); Monopoli, Marco [Centre for BioNanoInteractions, School of Chemistry and Chemical Biology, University College Dublin (Ireland); Corsi, Ilaria, E-mail: ilaria.corsi@unisi.it [Department of Physical, Earth and Environmental Sciences, University of Siena (Italy)

    2015-10-30

    Highlights: • Nano-TiO{sub 2} modulate CdCl{sub 2} cellular responses in gills of marine mussel. • Nano-TiO{sub 2} reduced CdCl{sub 2}-induced effects by lowering abcb1 m-RNA and GST activity. • Nano-TiO{sub 2} reduced Cd accumulation in mussel’s gills but not in whole soft tissue. • Higher accumulation of Ti in the presence of CdCl{sub 2} was observed in gills. - Abstract: We investigated the influence of titanium dioxide nanoparticles (nano-TiO{sub 2}) on the response to cadmium in the gills of the marine mussel Mytilus galloprovincialis in terms of accumulation and toxicity. Mussels were in vivo exposed to nano-TiO{sub 2}, CdCl{sub 2}, alone and in combination. Several cellular biomarkers were investigated in gills: ABC transport proteins and metallothioneins at gene/protein (abcb1, abcc-like and mt-20) and functional level, GST activity, NO production and DNA damage (Comet assay). Accumulation of total Cd and titanium in gills as in whole soft tissue was also investigated. Significant responses to Cd exposure were observed in mussel gills as up-regulation of abcb1 and mt-20 gene transcription, increases in total MT content, P-gp efflux and GST activity, DNA damage and NO production. Nano-TiO{sub 2} alone increased P-gp efflux activity and NO production. When combined with Cd, nano-TiO{sub 2} reduced the metal-induced effects by significantly lowering abcb1 gene transcription, GST activity, and DNA damage, whereas, additive effects were observed on NO production. A lower concentration of Cd was observed in the gills upon co-exposure, whereas, Ti levels were unaffected. A competitive effect in uptake/accumulation of nano-TiO{sub 2} and Cd seems to occur in gills. A confirmation is given by the observed absence of adsorption of Cd onto nano-TiO{sub 2} in sea water media.

  1. Characterization of titanium dioxide nanoparticles in food products: Analytical methods to define nanoparticles

    NARCIS (Netherlands)

    Peters, R.J.B.; Bemmel, G. van; Herrera-Rivera, Z.; Helsper, H.P.F.G.; Marvin, H.J.P.; Weigel, S.; Tromp, P.C.; Oomen, A.G.; Rietveld, A.G.; Bouwmeester, H.

    2014-01-01

    Titanium dioxide (TiO2) is a common food additive used to enhance the white color, brightness, and sometimes flavor of a variety of food products. In this study 7 food grade TiO2 materials (E171), 24 food products, and 3 personal care products were investigated for their TiO 2 content and the

  2. Characterization of Titanium Dioxide Nanoparticles in Food Products: Analytical Methods To Define Nanoparticles

    NARCIS (Netherlands)

    Peters, R.J.B.; Bemmel, van M.E.M.; Herrera-Rivera, Z.; Helsper, J.P.F.G.; Marvin, H.J.P.; Weigel, S.; Tromp, P.C.; Oomen, A.G.; Rietveld, A.G.; Bouwmeester, H.

    2014-01-01

    Titanium dioxide (TiO2) is a common food additive used to enhance the white color, brightness, and sometimes flavor of a variety of food products. In this study 7 food grade TiO2 materials (E171), 24 food products, and 3 personal care products were investigated for their TiO2 content and the

  3. In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles

    Directory of Open Access Journals (Sweden)

    Farzin Heravi

    2013-12-01

    Full Text Available Background and aims. Incorporation of nano-particles to orthodontic bonding systems has been considered to prevent enamel demineralization around appliances. This study investigated cytotoxicity of Transbond XT adhesive containing 1 wt% titanium dioxide (TiO2 nano-particles. Materials and methods. Ten composite disks were prepared from each of the conventional and TiO2-containg composites and aged for 1, 3, 5, 7 and 14 days in Dulbecco’s Modified Eagle’s Medium (DMEM. The extracts were obtained and exposed to culture media of human gingival fibroblasts (HGF and mouse L929 fibroblasts. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Results. Both adhesives were moderately toxic for HGF cells on the first day of the experiment, but the TiO2-containing adhesive produced significantly lower toxicity than the pure adhesive (P0.05. There was a significant reduction in cell toxicity with increasing pre-incubation time (P<0.001. L929 cells showed similar toxicity trends, but lower sensitivity to detect cytotoxicity of dental composites. Conclusion. The orthodontic adhesive containing TiO2 nano-particles indicated comparable or even lower toxicity than its nano-particle-free counterpart, indicating that incorporation of 1 wt% TiO2 nano-particles to the composite structure does not result in additional health hazards compared to that occurring with the pure adhesive.

  4. Silver impregnated nanoparticles of titanium dioxide as carriers for {sup 211}At

    Energy Technology Data Exchange (ETDEWEB)

    Cedrowska, Edyta; Lyczko, Monika; Piotrowska, Agata; Bilewicz, Aleksander [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Stolarz, Anna; Trcinska, Agnieszka [Warsaw Univ. (Poland). Heavy Ion Lab.; Szkliniarz, Katarzyna [Silesia Univ. Katowice (Poland). Inst. of Physics; Was, Bogdan [Polish Academy of Science, Cracow (Poland). Inst. of Nuclear Physics

    2016-08-01

    The {sup 211}At radioisotope exhibits very attractive nuclear properties for application in radionuclide therapy. Unfortunately use of {sup 211}At is limited, because astatine as the heaviest halogen forms weak bond with carbon atoms in the biomolecules which makes {sup 211}At bioconjugates unstable in physiological conditions. In our work we propose a new solution for binding of {sup 211}At which consists of using nanoparticles of titanium dioxide modified with silver atoms as carriers for {sup 211}At. Ag{sup +} cations have been absorbed on the nanometer-sized TiO{sub 2} particles (15 and 32 nm) through ion exchange process and were reduced in Tollens' reaction. The obtained TiO{sub 2}-Ag nanoparticles were labeled with {sup 211}At. It was found that labeling yields were almost quantitative under reducing conditions, while under oxidizing conditions they dropped to about 80%. The labeled nanoparticles exhibited very high stability in physiological salt, PBS buffer, solutions of peptides (0.001 M cysteine, 0.001 M glutathione) and in human blood serum. To make TiO{sub 2}/Ag nanoparticles well dispersed in water and biocompatible their surface was modified with a silane coupling agent containing poly(ethyleneglycol) molecules. The developed functionalization approach will allow us to attach biomolecules to the TiO{sub 2}/Ag surface.

  5. In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles.

    Science.gov (United States)

    Heravi, Farzin; Ramezani, Mohammad; Poosti, Maryam; Hosseini, Mohsen; Shajiei, Arezoo; Ahrari, Farzaneh

    2013-01-01

    Background and aims. Incorporation of nano-particles to orthodontic bonding systems has been considered to prevent enamel demineralization around appliances. This study investigated cytotoxicity of Transbond XT adhesive containing 1 wt% titanium dioxide (TiO2) nano-particles. Materials and methods. Ten composite disks were prepared from each of the conventional and TiO2-containg composites and aged for 1, 3, 5, 7 and 14 days in Dulbecco's Modified Eagle's Medium (DMEM). The extracts were obtained and exposed to culture media of human gingival fibroblasts (HGF) and mouse L929 fibroblasts. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results. Both adhesives were moderately toxic for HGF cells on the first day of the experiment, but the TiO2-containing adhesive produced significantly lower toxicity than the pure adhesive (P0.05). There was a significant reduction in cell toxicity with increasing pre-incubation time (Porthodontic adhesive containing TiO2 nano-particles indicated comparable or even lower toxicity than its nano-particle-free counterpart, indicating that incorporation of 1 wt% TiO2 nano-particles to the composite structure does not result in additional health hazards compared to that occurring with the pure adhesive.

  6. Toxicity of titanium dioxide nanoparticles to Chlorella vulgaris Beyerinck (Beijerinck) 1890 (Trebouxiophyceae, Chlorophyta) under changing nitrogen conditions.

    Science.gov (United States)

    Dauda, Suleiman; Chia, Mathias Ahii; Bako, Sunday Paul

    2017-06-01

    The broad application of titanium dioxide nanoparticles (n-TiO 2 ) in many consumer products has resulted in the release of substantial quantities into aquatic systems. While n-TiO 2 have been shown to induce some unexpected toxic effects on aquatic organisms such as microalgae, the influence of changing nutrient conditions on the toxicity of the metal has not been investigated. We evaluated the toxicity of n-TiO 2 to Chlorella vulgaris under varying nitrogen conditions. Limited nitrogen (2.2μM) decreased growth and biomass (dry weight and pigment content), while lipid peroxidation (malondialdehyde content), glutathione S-transferase activity (GST) and peroxidase (POD) activity were increased. Similarly, exposure to n-TiO 2 under replete nitrogen condition resulted in a general decrease in growth and biomass, while GST and POD activities were significantly increased. The combination of limited nitrogen with n-TiO 2 exposure further decreased growth and biomass, and increased GST and POD activities of the microalga. These results suggest that in addition to the individual effects of each investigated condition, nitrogen limitation makes C. vulgaris more susceptible to the effects of n-TiO 2 with regard to some physiological parameters. This implies that the exposure of C. vulgaris and possibly other green algae to this nanoparticle under limited or low nitrogen conditions may negatively affect their contribution to primary production in oligotrophic aquatic ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Visible Light Photocatalytic Properties of Modified Titanium Dioxide Nanoparticles via Aluminium Treatment

    Directory of Open Access Journals (Sweden)

    Dessy Ariyanti

    2016-03-01

    Full Text Available Titanium dioxide (TiO2 has gained much attentions for the last few decades due to its remarkable performance in photocatalysis and some other related properties. However, its wide bandgap (~3.2 eV can only absorb UV energy which is only ~5% of solar light spectrum. The objective of this research was to improve the photocatalytic activity of TiO2 by improving the optical absorption to the visible light range. Here, colored TiO2 nanoparticles range from light to dark grey were prepared via aluminium treatment at the temperatures ranging from 400 to 600 oC. The modified TiO2 is able to absorb up to 50% of visible light (400-700 nm and shows a relatively good photocatalytic activity in organic dye (Rhodamine B degradation under visible light irradiation compared with the commercial TiO2. Copyright © 2016 BCREC GROUP. All rights reserved Received: 10th November 2015; Revised: 7th January 2016; Accepted: 7th January 20 How to Cite: Ariyanti, D., Dong, J.Z., Dong, J.Y., Gao, W. (2016. Visible Light Photocatalytic Properties of Modified Titanium Dioxide Nanoparticles via Aluminium Treatment. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1: 40-47. (doi:10.9767/bcrec.11.1.414.40-47 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.414.40-47

  8. HIGH-QUALITY ORNAMENTAL FINE CONCRETES MODIFIED BY NANOPARTICLES OF TITANIUM DIOXIDE

    Directory of Open Access Journals (Sweden)

    Bazhenov Yuriy Mikhaylovich

    2012-10-01

    Full Text Available Ultrasonic method of generation of a stable suspension of nano-particles of titanium dioxide and the strengthening properties of the ornamental fine concrete that contains cement binders with a nano-dispersed additive constitute the subject of the research covered by the authors. Nanoparticles react with the basic chemical elements that compose the concrete and act as crystallization centres. Therefore, the concrete porosity is reduced, while physical and technology-related properties of the ornamental fine concrete are improved. The authors have proven that the application of the nano-dispersed additive that contains titanium dioxide influences the processes of the structure formation in respect of fine ornamental concretes and improves the strength, as well as the water and cold resistance of fine concretes. The improvement is attributed to the dense concrete structure and strong adhesion between cement grains and between the cement and the aggregate. This conclusion is based on the data obtained through the employment of an electronic microscope used to identify the porosity of fine concretes.

  9. Photocatalytic Degradation Effect of μ-Dielectric Barrier Discharge Plasma Treated Titanium Dioxide Nanoparticles on Environmental Contaminant.

    Science.gov (United States)

    Seo, Hyeon Jin; Hwang, Ki-Hwan; Na, Young Hoon; Boo, Jin-Hyo

    2018-09-01

    This study focused on the photocatalytic degradation effect of the μ-dielectric barrier discharge (μ-DBD) plasma treated titanium dioxide (TiO2) nanoparticles on environmental contaminant such as formaldehyde. TiO2 nanoparticles were treated by a μ-DBD plasma source with nitrogen gas. We analyzed the degradation of formaldehyde with the plasma treated TiO2 nanoparticles by UV-visible spectrophotometer (UV-VIS), and demonstrated that the photocatalytic activity of the μ-DBD plasma-treated TiO2 nanoparticles showed significantly high catalytic efficiency rather than without plasma treated TiO2 nanoparticles. Field emission scanning electron microscopes (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and water contact angle analyzer were used to measure the effects of photocatalytic degradation for the plasma treated TiO2 nanoparticles.

  10. Twenty-fold plasmon-induced enhancement of radiative emission rate in silicon nanocrystals embedded in silicon dioxide

    International Nuclear Information System (INIS)

    Gardelis, S; Gianneta, V.; Nassiopoulou, A.G

    2016-01-01

    We report on a 20-fold enhancement of the integrated photoluminescence (PL) emission of silicon nanocrystals, embedded in a matrix of silicon dioxide, induced by excited surface plasmons from silver nanoparticles, which are located in the vicinity of the silicon nanocrystals and separated from them by a silicon dioxide layer of a few nanometers. The electric field enhancement provided by the excited surface plasmons increases the absorption cross section and the emission rate of the nearby silicon nanocrystals, resulting in the observed enhancement of the photoluminescence, mainly attributed to a 20-fold enhancement in the emission rate of the silicon nanocrystals. The observed remarkable improvement of the PL emission makes silicon nanocrystals very useful material for photonic, sensor and solar cell applications.

  11. Cell-based cytotoxicity assays for engineered nanomaterials safety screening: exposure of adipose derived stromal cells to titanium dioxide nanoparticles.

    Science.gov (United States)

    Xu, Yan; Hadjiargyrou, M; Rafailovich, Miriam; Mironava, Tatsiana

    2017-07-11

    Increasing production of nanomaterials requires fast and proper assessment of its potential toxicity. Therefore, there is a need to develop new assays that can be performed in vitro, be cost effective, and allow faster screening of engineered nanomaterials (ENMs). Herein, we report that titanium dioxide (TiO 2 ) nanoparticles (NPs) can induce damage to adipose derived stromal cells (ADSCs) at concentrations which are rated as safe by standard assays such as measuring proliferation, reactive oxygen species (ROS), and lactate dehydrogenase (LDH) levels. Specifically, we demonstrated that low concentrations of TiO 2 NPs, at which cellular LDH, ROS, or proliferation profiles were not affected, induced changes in the ADSCs secretory function and differentiation capability. These two functions are essential for ADSCs in wound healing, energy expenditure, and metabolism with serious health implications in vivo. We demonstrated that cytotoxicity assays based on specialized cell functions exhibit greater sensitivity and reveal damage induced by ENMs that was not otherwise detected by traditional ROS, LDH, and proliferation assays. For proper toxicological assessment of ENMs standard ROS, LDH, and proliferation assays should be combined with assays that investigate cellular functions relevant to the specific cell type.

  12. Algal testing of titanium dioxide nanoparticles-Testing considerations, inhibitory effects and modification of cadmium bioavailability

    International Nuclear Information System (INIS)

    Hartmann, N.B.; Von der Kammer, F.; Hofmann, T.; Baalousha, M.; Ottofuelling, S.; Baun, A.

    2010-01-01

    The ecotoxicity of three different sizes of titanium dioxide (TiO 2 ) particles (primary particles sizes: 10, 30, and 300 nm) to the freshwater green alga Pseudokirchneriella subcapitata was investigated in this study. Algal growth inhibition was found for all three particle types, but the physiological mode of action is not yet clear. It was possible to establish a concentration/dose-response relationship for the three particle sizes. Reproducibility, however, was affected by concentration-dependent aggregation of the nanoparticles, subsequent sedimentation, and possible attachment to vessel surfaces. It is also believed that heteroaggregation, driven by algal exopolymeric exudates, is occurring and could influence the concentration-response relationship. The ecotoxicity of cadmium to algae was investigated both in the presence and absence of 2 mg/L TiO 2 . The presence of TiO 2 in algal tests reduced the observed toxicity due to decreased bioavailability of cadmium resulting from sorption/complexation of Cd 2+ ions to the TiO 2 surface. However, for the 30 nm TiO 2 nanoparticles, the observed growth inhibition was greater than what could be explained by the concentration of dissolved Cd(II) species, indicating a possible carrier effect, or combined toxic effect of TiO 2 nanoparticles and cadmium. These results emphasize the importance of systematic studies of nanoecotoxicological effects of different sizes of nanoparticles and underline the fact that, in addition to particle toxicity, potential interactions with existing environmental contaminants are also of crucial importance in assessing the potential environmental risks of nanoparticles.

  13. Activated carbon-supported CuO nanoparticles: a hybrid material for carbon dioxide adsorption

    Science.gov (United States)

    Boruban, Cansu; Esenturk, Emren Nalbant

    2018-03-01

    Activated carbon-supported copper(II) oxide (CuO) nanoparticles were synthesized by simple impregnation method to improve carbon dioxide (CO2) adsorption capacity of the support. The structural and chemical properties of the hybrid material were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (https://www.google.com.tr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CCsQFjAC&url=http%3A%2F%2Fwww.intertek.com%2Fanalytical-laboratories%2Fxrd%2F&ei=-5WZVYSCHISz7Aatqq-IAw&usg=AFQjCNFBlk-9wqy49foh8tskmbD-GGbG9g&sig2=eKrhYjO75rl_Id2sLGpq4w&bvm=bv.96952980,d.bGg) (XRD), X-ray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (AAS), and Brunauer-Emmett-Teller (BET) analyses. The analyses showed that CuO nanoparticles are well-distributed on the activated carbon surface. The CO2 adsorption behavior of the activated carbon-supported CuO nanoparticles was observed by thermogravimetric analysis (TGA), temperature programmed desorption (TPD), Fourier transform infrared (FTIR), and BET analyses. The results showed that CuO nanoparticle loading on activated carbon led to about 70% increase in CO2 adsorption capacity of activated carbon under standard conditions (1 atm and 298 K). The main contributor to the observed increase is an improvement in chemical adsorption of CO2 due to the presence of CuO nanoparticles on activated carbon.

  14. Synthesis, fractionation, and thin film processing of nanoparticles using the tunable solvent properties of carbon dioxide gas expanded liquids

    Science.gov (United States)

    Anand, Madhu

    nanoparticle populations. This study details the influence of various factors on the size separation process, such as the types of nanoparticles, ligand type and solvent type as well as the use of recursive fractionation and the time allowed for settling during each fractionation step. This size selective precipitation technique was also applied to fractionate and separate polydisperse dispersions of CdSe/ZnS semiconductor nanocrystals into very distinct size and color fractions based solely on the pressure tunable solvent properties of CO2 expanded liquids. This size selective precipitation of nanoparticles is achieved by finely tuning the solvent strength of the CO2/organic solvent medium by simply adjusting the applied CO2 pressure. These subtle changes affect the balance between osmotic repulsive and van der Waals attractive forces thereby allowing fractionation of the nanocrystals into multiple narrow size populations. Thermodynamic analysis of nanoparticle size selective fractionation was performed to develop a theoretical model based on the thermodynamic properties of gas expanded liquids. We have used the general phenomenon of nanoparticle precipitation with CO2 expanded liquids to create dodecanethiol stabilized gold nanoparticle thin films. This method utilizes CO2 as an anti-solvent for low defect, wide area gold nanoparticle film formation employing monodisperse gold nanoparticles. Dodecanethiol stabilized gold particles are precipitated from hexane by controllably expanding the solution with carbon dioxide. Subsequent addition of carbon dioxide as a dense supercritical fluid then provides for removal of the organic solvent while avoiding the dewetting effects common to evaporating solvents. Unfortunately, the use of carbon dioxide as a neat solvent in nanoparticles synthesis and processing is limited by the very poor solvent strength of dense phase CO2. As a result, most current techniques employed to synthesize and disperse nanoparticles in neat carbon dioxide

  15. Pro-inflammatory responses of RAW264.7 macrophages when treated with ultralow concentrations of silver, titanium dioxide, and zinc oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Giovanni, Marcella [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585 (Singapore); Yue, Junqi; Zhang, Lifeng [PUB, 40 Scotts Road, Singapore 228231 (Singapore); Xie, Jianping [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585 (Singapore); Ong, Choon Nam [Saw Swee Hock School of Public Health, National University of Singapore, 12 Science Drive 2, Singapore 117549 (Singapore); NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411 (Singapore); Leong, David Tai, E-mail: cheltwd@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585 (Singapore)

    2015-10-30

    Highlights: • Ultralow levels of common nanoparticles exist in environment and consumer products. • Common nanoparticles at ultralow levels induce mild pro-inflammation by macrophages. • The nanoparticles are cytotoxic only at high doses. - Abstract: To cellular systems, nanoparticles are considered as foreign particles. Upon particles and cells contact, innate immune system responds by activating the inflammatory pathway. However, excessive inflammation had been linked to various diseases ranging from allergic responses to cancer. Common nanoparticles, namely silver, titanium dioxide, and zinc oxide exist in the environment as well as in consumer products at ultralow level of 10{sup −6}–10{sup −3} μg mL{sup −1}. However, so far the risks of such low NPs concentrations remain unexplored. Therefore, we attempted to screen the pro-inflammatory responses after ultralow concentration treatments of the three nanoparticles on RAW264.7 macrophages, which are a part of the immune system, at both cellular and gene levels. Even though cytotoxicity was only observed at nanoparticles concentrations as high as 10 μg mL{sup −1}, through the level of NF-κB and upregulation of pro-inflammatory genes, we observed activation of the induction of genes encoding pro-inflammatory cytokines starting already at 10{sup −7} μg mL{sup −1}. This calls for more thorough characterization of nanoparticles in the environment as well as in consumer products to ascertain the health and safety of the consumers and living systems in general.

  16. TiO{sub 2} nanoparticle-induced ROS correlates with modulated immune cell function

    Energy Technology Data Exchange (ETDEWEB)

    Maurer-Jones, Melissa A.; Christenson, Jenna R.; Haynes, Christy L., E-mail: chaynes@umn.edu [University of Minnesota, Department of Chemistry (United States)

    2012-12-15

    Design of non-toxic nanoparticles will be greatly facilitated by understanding the nanoparticle-cell interaction mechanism on a cell function level. Mast cells are important cells for the immune system's first line of defense, and we can utilize their exocytotic behavior as a model cellular function as it is a conserved process across cell types and species. Perturbations in exocytosis can also have implications for whole organism health. One proposed mode of toxicity is nanoparticle-induced reactive oxygen species (ROS), particularly for titanium dioxide (TiO{sub 2}) nanoparticles. Herein, we have correlated changes in ROS with the perturbation of the critical cell function of exocytosis, using UV light to induce greater levels of ROS in TiO{sub 2} exposed cells. The primary culture mouse peritoneal mast cells (MPMCs) were exposed to varying concentrations of TiO{sub 2} nanoparticles for 24 h. ROS content was determined using 2,7-dihydrodichlorofluorescein diacetate (DCFDA). Cellular viability was determined with the MTT and Trypan blue assays, and exocytosis was measured by the analytical electrochemistry technique of carbon-fiber microelectrode amperometry. MPMCs exposed to TiO{sub 2} nanoparticles experienced a dose-dependent increase in total ROS content. While there was minimal impact of ROS on cellular viability, there is a correlation between ROS amount and exocytosis perturbation. As nanoparticle-induced ROS increases, there is a significant decrease (45 %) in the number of serotonin molecules being released during exocytosis, increase (26 %) in the amount of time for each exocytotic granule to release, and decrease (28 %) in the efficiency of granule trafficking and docking. This is the first evidence that nanoparticle-induced ROS correlates with chemical messenger molecule secretion, possibly making a critical connection between functional impairment and mechanisms contributing to that impairment.

  17. Photocatalytic degradation of furfural in aqueous solution by N-doped titanium dioxide nanoparticles.

    Science.gov (United States)

    Veisi, Farzaneh; Zazouli, Mohammad Ali; Ebrahimzadeh, Mohammad Ali; Charati, Jamshid Yazdani; Dezfoli, Amin Shiralizadeh

    2016-11-01

    The photocatalytic degradation of furfural in aqueous solution was investigated using N-doped titanium dioxide nanoparticles under sunlight and ultraviolet radiation (N-TiO 2 /Sun and N-TiO 2 /UV) in a lab-scale batch photoreactor. The N-TiO 2 nanoparticles prepared using a sol-gel method were characterized using XRD, X-ray photoelectron spectroscopy (XPS), and SEM analyses. Using HPLC to monitor the furfural concentration, the effect of catalyst dosage, contact time, initial solution pH, initial furfural concentration, and sunlight or ultraviolet radiation on the degradation efficiency was studied. The efficiency of furfural removal was found to increase with increased reaction time, nanoparticle loading, and pH for both processes, whereas the efficiency decreased with increased furfural concentration. The maximum removal efficiencies for the N-TiO 2 /UV and N-TiO 2 /Sun processes were 97 and 78 %, respectively, whereas the mean removal efficiencies were 80.71 ± 2.08 % and 62.85 ± 2.41 %, respectively. In general, the degradation and elimination rate of furfural using the N-TiO 2 /UV process was higher than that using the N-TiO 2 /Sun process.

  18. Effects of Material Properties on Sedimentation and Aggregation of Titanium Dioxide Nanoparticles of Anatase and Rutile in the Aqueous Phase

    Science.gov (United States)

    This study investigated the sedimentation and aggregation kinetics of titanium dioxide (TiO2) nanoparticles with varying material properties (i.e., crystallinity, morphology, and chemical compositions). Used in the study were various types of commercially available TiO2 nanoparti...

  19. Photocatalytic effects of titanium dioxide nanoparticles on aquatic organisms—Current knowledge and suggestions for future research

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, Vena N., E-mail: vena.haynes@uconn.edu [University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, Groton, CT 06340 (United States); Ward, J. Evan, E-mail: evan.ward@uconn.edu [University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, Groton, CT 06340 (United States); Russell, Brandon J., E-mail: brandon.russell@uconn.edu [University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, Groton, CT 06340 (United States); Agrios, Alexander G., E-mail: agrios@engr.uconn.edu [University of Connecticut, Department of Civil & Environmental Engineering, 261 Glenbrook Road Unit 3037, Storrs, CT 06269 (United States)

    2017-04-15

    Highlights: • Ecotoxicological approaches are needed to predict effects of photoactive nanomaterials. • Research on effects of photoactive nanomaterials must include defined light fields. • Light fields must be appropriate for depth, latitude, season and water properties. • Physicochemical properties of water can alter light fields and photoreactivity. - Abstract: Nanoparticles are entering natural systems through product usage, industrial waste and post-consumer material degradation. As the production of nanoparticles is expected to increase in the next decade, so too are predicted environmental loads. Engineered metal-oxide nanomaterials, such as titanium dioxide, are known for their photocatalytic capabilities. When these nanoparticles are exposed to ultraviolet radiation in the environment, however, they can produce radicals that are harmful to aquatic organisms. There have been a number of studies that have reported the toxicity of titanium dioxide nanoparticles in the absence of light. An increasing number of studies are assessing the interactive effects of nanoparticles and ultraviolet light. However, most of these studies neglect environmentally-relevant experimental conditions. For example, researchers are using nanoparticle concentrations and light intensities that are too high for natural systems, and are ignoring water constituents that can alter the light field. The purpose of this review is to summarize the current knowledge of the photocatalytic effects of TiO{sub 2} nanoparticles on aquatic organisms, discuss the limitations of these studies, and outline environmentally-relevant factors that need to be considered in future experiments.

  20. Photocatalytic effects of titanium dioxide nanoparticles on aquatic organisms-Current knowledge and suggestions for future research.

    Science.gov (United States)

    Haynes, Vena N; Ward, J Evan; Russell, Brandon J; Agrios, Alexander G

    2017-04-01

    Nanoparticles are entering natural systems through product usage, industrial waste and post-consumer material degradation. As the production of nanoparticles is expected to increase in the next decade, so too are predicted environmental loads. Engineered metal-oxide nanomaterials, such as titanium dioxide, are known for their photocatalytic capabilities. When these nanoparticles are exposed to ultraviolet radiation in the environment, however, they can produce radicals that are harmful to aquatic organisms. There have been a number of studies that have reported the toxicity of titanium dioxide nanoparticles in the absence of light. An increasing number of studies are assessing the interactive effects of nanoparticles and ultraviolet light. However, most of these studies neglect environmentally-relevant experimental conditions. For example, researchers are using nanoparticle concentrations and light intensities that are too high for natural systems, and are ignoring water constituents that can alter the light field. The purpose of this review is to summarize the current knowledge of the photocatalytic effects of TiO 2 nanoparticles on aquatic organisms, discuss the limitations of these studies, and outline environmentally-relevant factors that need to be considered in future experiments. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Titanium Dioxide Exposure Induces Acute Eosinophilic Lung Inflammation in Rabbits

    Science.gov (United States)

    CHOI, Gil Soon; OAK, Chulho; CHUN, Bong-Kwon; WILSON, Donald; JANG, Tae Won; KIM, Hee-Kyoo; JUNG, Mannhong; TUTKUN, Engin; PARK, Eun-Kee

    2014-01-01

    Titanium dioxide (TiO2) is increasingly widely used in industrial, commercial and home products. TiO2 aggravates respiratory symptoms by induction of pulmonary inflammation although the mechanisms have not been well investigated. We aimed to investigate lung inflammation in rabbits after intratracheal instillation of P25 TiO2. One ml of 10, 50 and 250 µg of P25 TiO2 was instilled into one of the lungs of rabbits, chest computed-tomography was performed, and bronchoalveolar lavage (BAL) fluid was collected before, at 1 and 24 h after P25 TiO2 exposure. Changes in inflammatory cells in the BAL fluids were measured. Lung pathological assay was also carried out at 24 h after P25 TiO2 exposure. Ground glass opacities were noted in both lungs 1 h after P25 TiO2 and saline (control) instillation. Although the control lung showed complete resolution at 24 h, the lung exposed to P25 TiO2 showed persistent ground glass opacities at 24 h. The eosinophil counts in BAL fluid were significantly increased after P25 TiO2 exposure. P25 TiO2 induced a dose dependent increase of eosinophils in BAL fluid but no significant differences in neutrophil and lymphocyte cell counts were detected. The present findings suggest that P25 TiO2 induces lung inflammation in rabbits which is associated with eosinophilic inflammation. PMID:24705802

  2. Antimicrobial activity of zinc and titanium dioxide nanoparticles against biofilm-producing methicillin-resistant Staphylococcus aureus

    Science.gov (United States)

    Jesline, A.; John, Neetu P.; Narayanan, P. M.; Vani, C.; Murugan, Sevanan

    2015-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major nosocomial pathogens responsible for a wide spectrum of infections and the emergence of bacterial resistance to antibiotics has lead to treatment drawbacks towards large number of drugs. Formation of biofilms is the main contributing factor to antibiotic resistance. The development of reliable processes for the synthesis of zinc oxide nanoparticles is an important aspect of nanotechnology today. Zinc oxide and titanium dioxide nanoparticles comprise well-known inhibitory and bactericidal effects. Emergence of antimicrobial resistance by pathogenic bacteria is a major health problem in recent years. This study was designed to determine the efficacy of zinc and titanium dioxide nanoparticles against biofilm producing methicillin-resistant S. aureus. Biofilm production was detected by tissue culture plate method. Out of 30 MRSA isolates, 22 isolates showed strong biofilm production and 2 showed weak and moderate biofilm formation. Two strong and weak biofilm-producing methicillin-resistant S. aureus isolates were subjected to antimicrobial activity using commercially available zinc and titanium dioxide nanoparticles. Thus, the nanoparticles showed considerably good activity against the isolates, and it can be concluded that they may act as promising, antibacterial agents in the coming years.

  3. The effect of doping titanium dioxide nanoparticles on phase transformation, photocatalytic activity and anti-bacterial properties

    Science.gov (United States)

    Buzby, Scott Edward

    Nanosized titanium dioxide has a variety of important applications in everyday life including a photocatalyst for pollution remediation, photovoltaic devices, sunscreen, etc. This study focuses on the various properties of titanium dioxide nanoparticles doped with various cation and anion species. Samples were produced by various methods including metalorganic chemical vapor deposition (MOCVD), plasma assisted metalorganic chemical vapor deposition (PA-MOCVD) and sol-gel. Numerous techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy both scanning (SEM) and transmission (TEM) were used for physical characterization. Photocatalytic properties were determined by the oxidation of methylene blue dye and 2-chlorophenol in water as well as gaseous formic acid with results analyzed by high performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and ultra violet - visible spectroscopy (UV-VIS). For the purpose of enhancement of the photocatalytic activity of titanium dioxide nanoparticles, the effect of anion doping and the anatase-rutile phase ratio were studied. Although anatase, rutile and mixed crystallite phases all show some degree of activity in photocatalytic reactions, these results show that anatase is better suited for the degradation of organic compounds in an aqueous medium any advantage in photocatalytic activity gained through the enhancement in optical response from the smaller band gap by addition of rutile was overcome by the negatives associated with the rutile phase. Furthermore substitutional nitrogen doping showed significant improvement in UV photocatalysis as well as allowing for visible light activation of the catalyst. Further studies on the phase transitions in titanium dioxide nanoparticles were carried out by synthesizing various cation doped samples by sol-gel. Analysis of the phases by XRD showed an inverse relationship between dopant size and rutile percentage

  4. Risk assessment of amorphous silicon dioxide nanoparticles in a glass cleaner formulation

    Science.gov (United States)

    Scheel, Julia; Karsten, Stefan; Stelter, Norbert; Wind, Thorsten

    2013-01-01

    Since nanomaterials are a heterogeneous group of substances used in various applications, risk assessment needs to be done on a case-by-case basis. Here the authors assess the risk (hazard and exposure) of a glass cleaner with synthetic amorphous silicon dioxide (SAS) nanoparticles during production and consumer use (spray application). As the colloidal material used is similar to previously investigated SAS, the hazard profile was considered to be comparable. Overall, SAS has a low toxicity. Worker exposure was analysed to be well controlled. The particle size distribution indicated that the aerosol droplets were in a size range not expected to reach the alveoli. Predictive modelling was used to approximate external exposure concentrations. Consumer and environmental exposure were estimated conservatively and were not of concern. It was concluded based on the available weight-of-evidence that the production and application of the glass cleaner is safe for humans and the environment under intended use conditions. PMID:22548260

  5. Mediatorless Impedance Studies with Titanium Dioxide Conjugated Gold Nanoparticles for Hydrogen Peroxide Detection

    Directory of Open Access Journals (Sweden)

    Nur Hamidah Abdul Halim

    2017-09-01

    Full Text Available An impedimetric-based biosensor constructed using gold nanoparticles (AuNP entrapped within titanium dioxide (TiO2 particles for hydrogen peroxide (H2O2 detection is the main feature of this research. The matrix of the biosensor employed the surface of TiO2, which was previously modified with an amine terminal group using 3-Aminopropyltriethoxysilane (APTS at a low temperature to create a ready to immobilise surface for the biosensor application. Hemoglobin (Hb, which exhibits peroxidase-like activity, was used as the bioreceptor in the biosensor to detect H2O2 in solution. The analysis was carried out using an alternative impedance method, in which the biosensor exhibited a wide linear range response between 1 × 10−4 M and 1.5 × 10−2 M and a limit of detection (LOD of 1 × 10−5 M without a redox mediator.

  6. Ion-induced effects on metallic nanoparticles

    International Nuclear Information System (INIS)

    Klimmer, Andreas

    2010-01-01

    This work deals with the ion-irradiation of metallic nanoparticles in combination with various substrates. Particle diameters were systematically varied within the range of 2.5-14 nm, inter-particle distances range from 30-120 nm. Irradiations were performed with various inert gas ions with energies of 200 keV, resulting in an average ion range larger than the particle dimensions and therefore the effects of irradiation are mainly due to creation of structural defects within the particles and the underlying substrate as well. The main part of this work deals with ion-induced burrowing of metallic nanoparticles into the underlying substrate. The use of micellar nanoparticles with sharp size distribution combined with AFM and TEM analysis allows a much more detailed look at this effect than other works on that topic so far. With respect to the particle properties also a detailed look on the effect of irradiation on the particle structure would be interesting, which might lead to a deliberate influence on magnetic properties, for example. Within the context of this work, first successful experiments were performed on FePt particles, showing a significant reduction of the ordering temperature leading to the magnetically interesting, ordered L1 0 phase. (orig.)

  7. Titanium dioxide nanoparticles: some aspects of toxicity/focus on the development.

    Science.gov (United States)

    Rollerova, E; Tulinska, J; Liskova, A; Kuricova, M; Kovriznych, J; Mlynarcikova, A; Kiss, A; Scsukova, S

    2015-04-01

    Nanosized titanium dioxide (TiO2) particles belong to the most widely manufactured nanoparticles (NPs) on a global scale because of their photocatalytic properties and the related surface effects. TiO2 NPs are in the top five NPs used in consumer products. Ultrafine TiO2 is widely used in the number of applications, including white pigment in paint, ceramics, food additive, food packaging material, sunscreens, cosmetic creams, and, component of surgical implants. Data evidencing rapid distribution, slow or ineffective elimination, and potential long-time tissue accumulation are especially important for the human risk assessment of ultrafine TiO2 and represent new challenges to more responsibly investigate potential adverse effects by the action of TiO2 NPs considering their ubiquitous exposure in various doses. Transport of ultrafine TiO2 particles in systemic circulation and further transition through barriers, especially the placental and blood-brain ones, are well documented. Therefore, from the developmental point of view, there is a raising concern in the exposure to TiO2 NPs during critical windows, in the pregnancy or the lactation period, and the fact that human mothers, women and men in fertile age and last but not least children may be exposed to high cumulative doses. In this review, toxicokinetics and particularly toxicity of TiO2 NPs in relation to the developing processes, oriented mainly on the development of the central nervous system, are discussed Keywords: nanoparticles, nanotoxicity, nanomaterials, titanium dioxide, reproductive toxicity, developmental toxicity, blood brain barrier, placental barrier.

  8. Silver and titanium dioxide nanoparticle toxicity in plants: A review of current research.

    Science.gov (United States)

    Cox, Ashley; Venkatachalam, P; Sahi, Shivendra; Sharma, Nilesh

    2016-10-01

    Nanoparticles (NPs) have become widely used in recent years for many manufacturing and medical processes. Recent literature suggests that many metallic nanomaterials including those of silver (Ag) and titanium dioxide (TiO2) cause significant toxic effects in animal cell culture and animal models, however, toxicity studies using plant species are limited. This review examines current progress in the understanding of the effect of silver and titanium dioxide nanoparticles on plant species. There are many facets to this ongoing environmental problem. This review addresses the effects of NPs on oxidative stress-related gene expression, genotoxicity, seed germination, and root elongation. It is largely accepted that NP exposure results in the cellular generation of reactive oxygen species (ROS), leading to both positive and negative effects on plant growth. However, factors such as NP size, shape, surface coating and concentration vary greatly among studies resulting in conflicting reports of the effect at times. In addition, plant species tend to differ in their reaction to NP exposure, with some showing positive effects of NP augmentation while many others showing detrimental effects. Seed germination studies have shown to be less effective in gauging phytotoxicity, while root elongation studies have shown more promise. Given the large increase in nanomaterial applications in consumer products, agriculture and energy sectors, it is critical to understand their role in the environment and their effects on plant life. A closer look at nanomaterial-driven ecotoxicity is needed. Ecosystem-level studies are required to indicate how these nanomaterials transfer at the critical trophic levels affecting human health and biota. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. Silymarin nanoparticle prevents paracetamol-induced hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Das S

    2011-06-01

    Full Text Available Suvadra Das, Partha Roy, Runa Ghosh Auddy, Arup MukherjeeDepartment of Chemical Technology, University of Calcutta, Kolkata, West Bengal, IndiaAbstract: Silymarin (Sm is a polyphenolic component extracted from Silybum marianum. It is an antioxidant, traditionally used as an immunostimulant, hepatoprotectant, and dietary supplement. Relatively recently, Sm has proved to be a valuable chemopreventive and a useful antineoplastic agent. Medical success for Sm is, however, constrained by very low aqueous solubility and associated biopharmaceutical limitations. Sm flavonolignans are also susceptible to ion-catalyzed degradation in the gut. Proven antihepatotoxic activity of Sm cannot therefore be fully exploited in acute chemical poisoning conditions like that in paracetamol overdose. Moreover, a synchronous delivery that is required for hepatic regeneration is difficult to achieve by itself. This work is meant to circumvent the inherent limitations of Sm through the use of nanotechnology. Sm nanoparticles (Smnps were prepared by nanoprecipitation in polyvinyl alcohol stabilized Eudragit RS100® polymer (Rohm Pharma GmbH, Darmstadt, Germany. Process parameter optimization provided 67.39% entrapment efficiency and a Gaussian particle distribution of average size 120.37 nm. Sm release from the nanoparticles was considerably sustained for all formulations. Smnps were strongly protective against hepatic damage when tested in a paracetamol overdose hepatotoxicity model. Nanoparticles recorded no animal death even when administered after an established paracetamol-induced hepatic necrosis. Preventing progress of paracetamol hepatic damage was traced for an efficient glutathione regeneration to a level of 11.3 µmol/g in hepatic tissue due to Smnps.Keywords: silymarin, paracetamol, nanoparticle, glutathione, mouse hepatotoxicity

  10. Electrospray deposition of titanium dioxide (TiO{sub 2}) nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Halimi, Siti Umairah, E-mail: fitrah@salam.uitm.edu.my; Bakar, Noor Fitrah Abu, E-mail: fitrah@salam.uitm.edu.my; Ismail, Siti Norazian, E-mail: fitrah@salam.uitm.edu.my; Hashib, Syafiza Abd, E-mail: fitrah@salam.uitm.edu.my [Faculty of Chemical Engineering, UniversitiTeknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Naim, M. Nazli [Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor (Malaysia)

    2014-02-24

    Deposition of titanium dioxide (TiO{sub 2}) nanoparticles was conducted by using eletrospray method. 0.05wt% of titanium dioxide suspension was prepared and characterized by using Malvern Zetasizer prior to the experiment. From Zetasizer results, stable suspension condition was obtained which is at pH 2 with zeta potential value of ±29.0 mV. In this electrospraying, the suspension was pumped at flowrate of 5 ml/hr by using syringe pump. The input voltage of 2.1 kV was applied at the nozzle tip and counter electrode. Electrosprayed particles were collected on the grounded aluminium plate substrate which was placed at 10–20 cm from counter electrode. Particles were then characterized using FESEM and average size of electrosprayed particles obtained. Initial droplet size was calculated by scaling law and compared with FE-SEM results in order to prove droplet fission occur during electrospray. Due to the results obtained, as the working distance increase from 10–20 cm the deposited TiO{sub 2} droplet size decrease from 247–116 nm to show droplet fission occur during the experiment.

  11. Carbon dioxide/methanol conversion cycle based on cascade enzymatic reactions supported on superparamagnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    CATERINA G.C. MARQUES NETTO

    2017-10-01

    Full Text Available ABSTRACT The conversion of carbon dioxide into important industrial feedstock is a subject of growing interest in modern society. A possible way to achieve this goal is by carrying out the CO2/methanol cascade reaction, allowing the recycle of CO2 using either chemical catalysts or enzymes. Efficient and selective reactions can be performed by enzymes; however, due to their low stability, immobilization protocols are required to improve their performance. The cascade reaction to reduce carbon dioxide into methanol has been explored by the authors, using, sequentially, alcohol dehydrogenase (ADH, formaldehyde dehydrogenase (FalDH, and formate dehydrogenase (FDH, powered by NAD+/NADH and glutamate dehydrogenase (GDH as the co-enzyme regenerating system. All the enzymes have been immobilized on functionalized magnetite nanoparticles, and their reactions investigated separately in order to establish the best performance conditions. Although the stepwise scheme led to only 2.3% yield of methanol per NADH; in a batch system under CO2 pressure, the combination of the four immobilized enzymes increased the methanol yield by 64 fold. The studies indicated a successful regeneration of NADH in situ, envisaging a real possibility of using immobilized enzymes to perform the cascade CO2-methanol reaction.

  12. Risk assessment of titanium dioxide nanoparticles via oral exposure, including toxicokinetic considerations.

    Science.gov (United States)

    Heringa, Minne B; Geraets, Liesbeth; van Eijkeren, Jan C H; Vandebriel, Rob J; de Jong, Wim H; Oomen, Agnes G

    2016-12-01

    Titanium dioxide white pigment consists of particles of various sizes, from which a fraction is in the nano range (food as additive E 171 as well as in other products, such as food supplements and toothpaste. Here, we assessed whether a human health risk can be expected from oral ingestion of these titanium dioxide nanoparticles (TiO 2 NPs), based on currently available information. Human health risks were assessed using two different approaches: Approach 1, based on intake, i.e. external doses, and Approach 2, based on internal organ concentrations using a kinetic model in order to account for accumulation over time (the preferred approach). Results showed that with Approach 1, a human health risk is not expected for effects in liver and spleen, but a human health risk cannot be excluded for effects on the ovaries. When based on organ concentrations by including the toxicokinetics of TiO 2 NPs (Approach 2), a potential risk for liver, ovaries and testes is found. This difference between the two approaches shows the importance of including toxicokinetic information. The currently estimated risk can be influenced by factors such as absorption, form of TiO 2 , particle fraction, particle size and physico-chemical properties in relation to toxicity, among others. Analysis of actual particle concentrations in human organs, as well as organ concentrations and effects in liver and the reproductive system after chronic exposure to well-characterized TiO 2 (NPs) in animals are recommended to refine this assessment.

  13. Hemocyte responses of Dreissena polymorpha following a short-term in vivo exposure to titanium dioxide nanoparticles: Preliminary investigations

    Energy Technology Data Exchange (ETDEWEB)

    Couleau, Nicolas; Techer, Didier [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), CNRS UMR 7146, IUT Thionville-Yutz, Espace Cormontaigne, Yutz, F-57970 (France); Pagnout, Christophe [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), UMR 7146, Campus Bridoux, rue du General Delestraint, Metz, F-57070 (France); International Consortium for the Environmental Implications of Nanotechnology, iCEINT, http://www.i-ceint.org (France); Jomini, Stephane [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), UMR 7146, Campus Bridoux, rue du General Delestraint, Metz, F-57070 (France); Foucaud, Laurent; Laval-Gilly, Philippe; Falla, Jairo [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), CNRS UMR 7146, IUT Thionville-Yutz, Espace Cormontaigne, Yutz, F-57970 (France); Bennasroune, Amar, E-mail: amar.bennasroune@univ-metz.fr [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), CNRS UMR 7146, IUT Thionville-Yutz, Espace Cormontaigne, Yutz, F-57970 (France)

    2012-11-01

    The widespread use of titanium-based nanoparticles and their environmental release may pose a significant risk to aquatic organisms within freshwater ecosystems. Suspension-feeder invertebrates like bivalve molluscs represent a unique target group for nanoparticle toxicology. The aim of this work was to investigate the short-term responses of Dreissena polymorpha hemocytes after in vivo exposure to titanium dioxide nanoparticles (TiO{sub 2} NP). For this purpose, freshwater mussels were exposed to P25 TiO{sub 2} NP at the concentrations of 0.1, 1, 5 and 25 mg/L during 24 h. Viability, phagocytosis activity and mitogen activated protein kinase (MAPK) phosphorylation level of ERK 1/2 and p38 in hemocytes extracted from exposed mussels were compared to those from control specimens. Results demonstrated an inhibition of the phagocytosis activity after exposure to TiO{sub 2} NP at 0.1 and 1 mg/L. Similar trends, albeit less pronounced, were reported for higher concentrations of NP. Transmission electron microscopy showed for the first time the internalization of TiO{sub 2} NP into Dreissena polymorpha hemocytes. Besides, exposure to NP increased the ERK 1/2 phosphorylation levels in all treatments. Concerning the phosphorylation level of p38, only exposures to 5 and 25 mg/L of NP induced significant p38 activation in comparison to that of the control. Finally, these short-term effects observed at environmentally relevant concentrations highlighted the need for further studies concerning ecotoxicological evaluation of nanoparticle release into an aquatic environment. -- Highlights: Black-Right-Pointing-Pointer Phagocytosis inhibition at TiO{sub 2} NP exposure concentrations of 0.1 and 1 mg/L. Black-Right-Pointing-Pointer Internalization of TiO{sub 2} NP in freshwater mussel hemocytes. Black-Right-Pointing-Pointer Increased phosphorylation level of p38 and ERK 1/2 after in vivo exposure to TiO{sub 2} NP.

  14. Biosynthesis of titanium dioxide nanoparticles using Bacillus amyloliquefaciens culture and enhancement of its photocatalytic activity for the degradation of a sulfonated textile dye Reactive Red 31.

    Science.gov (United States)

    Khan, Razia; Fulekar, M H

    2016-08-01

    The present study aims at exploiting Bacillus amyloliquefaciens for the biosynthesis of titanium dioxide nanoparticles and also investigates role of bacterial enzymes in the biosynthesis of titanium dioxide nanoparticles. Bacterial synthesized as well as metal doped titanium dioxide nanoparticles were characterized by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDAX). Amylase activity (43.37IU) in culture supernatant evinced a potential involvement of extracellular enzyme in TiO2 nanoparticle biosynthesis. Crystallite size of bio-synthesized nanoparticles was found to be in the range of 15.23-87.6nm. FTIR spectroscopy and native-PAGE (Polyacrylamide Gel Electrophoresis) clearly indicated involvement of alpha amylase in biosynthesis of TiO2 nanoparticles and in their stabilization. TEM micrographs of the synthesized titanium dioxide nanoparticles revealed the formation of spherical nanoparticles with a size range of 22.11-97.28nm. Photocatalytic degradation of Reactive Red 31 (RR31) dye was carried out using bio-synthesized TiO2 nanoparticles under UV radiation. Photocatalytic activity of synthesized nanoparticles was enhanced by Ag, La, Zn and Pt doping. Platinum doped TiO2 showed highest potential (90.98%) in RR31 degradation as compared to undoped (75.83%). Copyright © 2016 Elsevier Inc. All rights reserved.

  15. In situ effects of titanium dioxide nanoparticles on community structure of freshwater benthic macroinvertebrates.

    Science.gov (United States)

    Jovanović, Boris; Milošević, Djuradj; Piperac, Milica Stojković; Savić, Ana

    2016-06-01

    For the first time in the current literature, the effect of titanium dioxide (TiO2) nanoparticles on the community structure of macroinvertebrates has been investigated in situ. Macroinvertebrates were exposed for 100 days to an environmentally relevant concentration of TiO2 nanoparticles, 25 mg kg(-1) in sediment. Czekanowski's index was 0.61, meaning 39% of the macroinvertebrate community structure was affected by the TiO2 treatment. Non-metric multidimensional scaling (NMDS) visualized the qualitative and quantitative variability of macroinvertebrates at the community level among all samples. A distance-based permutational multivariate analysis of variance (PERMANOVA) revealed the significant effect of TiO2 on the macroinvertebrate community structure. The indicator value analysis showed that the relative frequency and abundance of Planorbarius corneus and Radix labiata were significantly lower in the TiO2 treatment than in the control. Meanwhile, Ceratopogonidae, showed a significantly higher relative frequency and abundance in the TiO2 treatment than in the control. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Bioaccumulation, Subacute Toxicity, and Tissue Distribution of Engineered Titanium Dioxide Nanoparticles in Goldfish (Carassius auratus

    Directory of Open Access Journals (Sweden)

    Mehmet Ates

    2013-01-01

    Full Text Available The increased use of nanosized materials is likely to result in the release of these particles into the environment. It is, however, unclear if these materials are harmful to aquatic animals. In this study, the sublethal effects of exposure of low and high concentrations of titanium dioxide nanoparticles (TiO2 NPs on goldfish (Carassius auratus were investigated. Accumulation of TiO2 NPs increased from 42.71 to 110.68 ppb in the intestine and from 4.10 to 9.86 ppb in the gills of the goldfish with increasing exposure dose from 10 to 100 mg/L TiO2 NPs. No significant accumulation in the muscle and brain of the fish was detected. Malondialdehyde as a biomarker of lipid oxidation was detected in the liver of the goldfish. Moreover, TiO2 NPs exposure inhibited growth of the goldfish. Although there was an increase (8.1% in the body weights of the goldfish for the control group, in the low and high exposure groups 1.8% increase and 19.7% decrease were measured, respectively. The results of this study contribute to the current understanding of the potential ecotoxicological effects of nanoparticles and highlight the importance of characterization of NPs in understanding their behavior, uptake, and effects in aquatic systems and in fish.

  17. XANES studies of titanium dioxide nanoparticles synthesized by using Peltophorum pterocarpum plant extract

    Energy Technology Data Exchange (ETDEWEB)

    Saravanan, S. [Centre for Photonics and Nanotechnology, Sona College of Technology, Salem 636005, Tamilnadu (India); Balamurugan, M., E-mail: chem.muruga@gmail.com [Centre for Photonics and Nanotechnology, Sona College of Technology, Salem 636005, Tamilnadu (India); Lippitz, A. [Bundesanstalt für Materialforschung und -prüfung, 6.8 Oberflächenanalytik und Grenzflächenchemie Unter den Eichen 44 – 46, 12203, Berlin (Germany); Fonda, E.; Swaraj, S. [Synchrotron SOLEIL, L’ormes des merisiers, Saint Aubin BP-48, 91192, Gif-Sur-Yvette Cedex (France)

    2016-12-15

    The preparation and characterization of a Titanium dioxide (TiO{sub 2}) by a simple, cost effective, facile and eco-friendly green synthesis method using Peltophorum pterocarpum plant extract is presented. The green synthesized nanoparticles were characterized using X-ray diffraction (XRD), Raman spectroscopy, High-resolution transmission electron microscopy (HR-TEM) and X-ray absorption near edge spectroscopy (XANES). XRD results show that the prepared TiO{sub 2} NPs were significantly crystalline with various percentages of anatase and rutile phases. The nanoparticles were found to have different diameters ranging from 20 to 80 nm. No evidence of any intermediate or different TiO{sub 2} phases were found in XANES measurements performed at the Ti K- and L-edge. It is shown that the TiO{sub 2} NPs with high uniformity, high surface area and minimum aggregation can be prepared with relative ease and the desired anatase: rutile phase ratio can be obtained by controlling the experimental conditions.

  18. Laser-produced plasma EUV source using a colloidal microjet target containing tin dioxide nanoparticles

    Science.gov (United States)

    Higashiguchi, Takeshi; Dojyo, Naoto; Sasaki, Wataru; Kubodera, Shoichi

    2006-10-01

    We realized a low-debris laser-produced plasma extreme ultraviolet (EUV) source by use of a colloidal microjet target, which contained low-concentration (6 wt%) tin-dioxide nanoparticles. An Nd:YAG laser was used to produce a plasma at the intensity on the order of 10^11 W/cm^2. The use of low concentration nanoparticles in a microjet target with a diameter of 50 μm regulated the neutral debris emission from a target, which was monitored by a silicon witness plate placed 30 cm apart from the source in a vacuum chamber. No XPS signals of tin and/or oxygen atoms were observed on the plate after ten thousand laser exposures. The low concentration nature of the target was compensated and the conversion efficiency (CE) was improved by introducing double pulses of two Nd:YAG lasers operated at 532 and 1064 nm as a result of controlling the micro-plasma characteristics. The EUV CE reached its maximum of 1.2% at the delay time of approximately 100 ns with the main laser intensiy of 2 x10^11 W/cm^2. The CE value was comparable to that of a tin bulk target, which, however, produced a significant amount of neutral debris.

  19. Titanium dioxide nanoparticles activate the ATM-Chk2 DNA damage response in human dermal fibroblasts

    Science.gov (United States)

    Prasad, Raju Y.; Chastain, Paul D.; Nikolaishvili-Feinberg, Nana; Smeester, Lisa M.; Kaufmann, William K.; Fry, Rebecca C.

    2013-01-01

    The use of nanoparticles in consumer products increases their prevalence in the environment and the potential risk to human health. Although recent studies have shown in vivo and in vitro toxicity of titanium dioxide nanoparticles (nano-TiO2), a more detailed view of the underlying mechanisms of this response needs to be established. Here the effects of nano-TiO2 on the DNA damage response and DNA replication dynamics were investigated in human dermal fibroblasts. Specifically, the relationship between nano-TiO2 and the DNA damage response pathways regulated by ATM/Chk2 and ATR/Chk1 were examined. The results show increased phosphorylation of H2AX, ATM, and Chk2 after exposure. In addition, nano-TiO2 inhibited the overall rate of DNA synthesis and frequency of replicon initiation events in DNA combed fibers. Taken together, these results demonstrate that exposure to nano-TiO2 activates the ATM/Chk2 DNA damage response pathway. PMID:22770119

  20. Optimized method of dispersion of titanium dioxide nanoparticles for evaluation of safety aspects in cosmetics

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Karina Penedo, E-mail: carvalho.kp@gmail.com; Martins, Nathalia Balthazar; Ribeiro, Ana Rosa Lopes Pereira; Lopes, Taliria Silva [National Institute of Metrology, Quality and Technology (INMETRO), Laboratory of Tissue Bioengineering, Division of Materials Applied To Life Sciences (Brazil); Sena, Rodrigo Caciano de [National Institute of Metrology, Quality and Technology (INMETRO), Laboratory of Inorganic Analysis, Division of Chemical Metrology (Brazil); Sommer, Pascal [Institute of Biology and Chemistry of Proteins (IBCP), Laboratory of Tissue Biology and Therapeutic Engineering (France); Granjeiro, José Mauro [National Institute of Metrology, Quality and Technology (INMETRO), Laboratory of Tissue Bioengineering, Division of Materials Applied To Life Sciences (Brazil)

    2016-08-15

    Nanoparticles agglomerate when in contact with biological solutions, depending on the solutions’ nature. The agglomeration state will directly influence cellular response, since free nanoparticles are prone to interact with cells and get absorbed into them. In sunscreens, titanium dioxide nanoparticles (TiO{sub 2}-NPs) form mainly aggregates between 30 and 150 nm. Until now, no toxicological study with skin cells has reached this range of size distribution. Therefore, in order to reliably evaluate their safety, it is essential to prepare suspensions with reproducibility, irrespective of the biological solution used, representing the above particle size distribution range of NPs (30–150 nm) found on sunscreens. Thus, the aim of this study was to develop a unique protocol of TiO{sub 2} dispersion, combining these features after dilution in different skin cell culture media, for in vitro tests. This new protocol was based on physicochemical characteristics of TiO{sub 2}, which led to the choice of the optimal pH condition for ultrasonication. The next step consisted of stabilization of protein capping with acidified bovine serum albumin, followed by an adjustment of pH to 7.0. At each step, the solutions were analyzed by dynamic light scattering and transmission electron microscopy. The final concentration of NPs was determined by inductively coupled plasma-optical emission spectroscopy. Finally, when diluted in dulbecco’s modified eagle medium, melanocytes growth medium, or keratinocytes growth medium, TiO{sub 2}–NPs displayed a highly reproducible size distribution, within the desired size range and without significant differences among the media. Together, these results demonstrate the consistency achieved by this new methodology and its suitability for in vitro tests involving skin cell cultures.

  1. Optimized method of dispersion of titanium dioxide nanoparticles for evaluation of safety aspects in cosmetics

    International Nuclear Information System (INIS)

    Carvalho, Karina Penedo; Martins, Nathalia Balthazar; Ribeiro, Ana Rosa Lopes Pereira; Lopes, Taliria Silva; Sena, Rodrigo Caciano de; Sommer, Pascal; Granjeiro, José Mauro

    2016-01-01

    Nanoparticles agglomerate when in contact with biological solutions, depending on the solutions’ nature. The agglomeration state will directly influence cellular response, since free nanoparticles are prone to interact with cells and get absorbed into them. In sunscreens, titanium dioxide nanoparticles (TiO_2-NPs) form mainly aggregates between 30 and 150 nm. Until now, no toxicological study with skin cells has reached this range of size distribution. Therefore, in order to reliably evaluate their safety, it is essential to prepare suspensions with reproducibility, irrespective of the biological solution used, representing the above particle size distribution range of NPs (30–150 nm) found on sunscreens. Thus, the aim of this study was to develop a unique protocol of TiO_2 dispersion, combining these features after dilution in different skin cell culture media, for in vitro tests. This new protocol was based on physicochemical characteristics of TiO_2, which led to the choice of the optimal pH condition for ultrasonication. The next step consisted of stabilization of protein capping with acidified bovine serum albumin, followed by an adjustment of pH to 7.0. At each step, the solutions were analyzed by dynamic light scattering and transmission electron microscopy. The final concentration of NPs was determined by inductively coupled plasma-optical emission spectroscopy. Finally, when diluted in dulbecco’s modified eagle medium, melanocytes growth medium, or keratinocytes growth medium, TiO_2–NPs displayed a highly reproducible size distribution, within the desired size range and without significant differences among the media. Together, these results demonstrate the consistency achieved by this new methodology and its suitability for in vitro tests involving skin cell cultures.

  2. Toxicity of titanium dioxide nanoparticles to rainbow trout (Oncorhynchus mykiss): Gill injury, oxidative stress, and other physiological effects

    Energy Technology Data Exchange (ETDEWEB)

    Federici, Gillian; Shaw, Benjamin J. [Ecotoxicology and Stress Biology Research Group, School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Handy, Richard D. [Ecotoxicology and Stress Biology Research Group, School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: rhandy@plymouth.ac.uk

    2007-10-30

    showed condensed nuclear bodies (apoptotic bodies). Fish probably ingested water containing TiO{sub 2} NPs during exposure (stress-induced drinking) which may have resulted in some areas of erosion on the intestinal epithelium. Overall we conclude that titanium dioxide nanoparticles are not a major ionoregulatory toxicant, or haemolytic, at the concentration and exposure times used. Respiratory distress is a concern and sub-lethal toxicity involves oxidative stress, organ pathologies, and the induction of anti-oxidant defences, such as glutathione.

  3. Characterization of titanium dioxide nanoparticles in food products: analytical methods to define nanoparticles.

    Science.gov (United States)

    Peters, Ruud J B; van Bemmel, Greet; Herrera-Rivera, Zahira; Helsper, Hans P F G; Marvin, Hans J P; Weigel, Stefan; Tromp, Peter C; Oomen, Agnes G; Rietveld, Anton G; Bouwmeester, Hans

    2014-07-09

    Titanium dioxide (TiO2) is a common food additive used to enhance the white color, brightness, and sometimes flavor of a variety of food products. In this study 7 food grade TiO2 materials (E171), 24 food products, and 3 personal care products were investigated for their TiO2 content and the number-based size distribution of TiO2 particles present in these products. Three principally different methods have been used to determine the number-based size distribution of TiO2 particles: electron microscopy, asymmetric flow field-flow fractionation combined with inductively coupled mass spectrometry, and single-particle inductively coupled mass spectrometry. The results show that all E171 materials have similar size distributions with primary particle sizes in the range of 60-300 nm. Depending on the analytical method used, 10-15% of the particles in these materials had sizes below 100 nm. In 24 of the 27 foods and personal care products detectable amounts of titanium were found ranging from 0.02 to 9.0 mg TiO2/g product. The number-based size distributions for TiO2 particles in the food and personal care products showed that 5-10% of the particles in these products had sizes below 100 nm, comparable to that found in the E171 materials. Comparable size distributions were found using the three principally different analytical methods. Although the applied methods are considered state of the art, they showed practical size limits for TiO2 particles in the range of 20-50 nm, which may introduce a significant bias in the size distribution because particles <20 nm are excluded. This shows the inability of current state of the art methods to support the European Union recommendation for the definition of nanomaterials.

  4. Comparison of Cellular Uptake and Inflammatory Response via Toll-Like Receptor 4 to Lipopolysaccharide and Titanium Dioxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Akiyoshi Taniguchi

    2013-06-01

    Full Text Available The innate immune response is the earliest cellular response to infectious agents and mediates the interactions between microbes and cells. Toll-like receptors (TLRs play an important role in these interactions. We have already shown that TLRs are involved with the uptake of titanium dioxide nanoparticles (TiO2 NPs and promote inflammatory responses. In this paper, we compared role of cellular uptake and inflammatory response via TLR 4 to lipopolysaccharide (LPS and TiO2 NPs. In the case of LPS, LPS binds to LPS binding protein (LBP and CD 14, and then this complex binds to TLR 4. In the case of TiO2 NPs, the necessity of LBP and CD 14 to induce the inflammatory response and for uptake by cells was investigated using over-expression, antibody blocking, and siRNA knockdown experiments. Our results suggested that for cellular uptake of TiO2 NPs, TLR 4 did not form a complex with LBP and CD 14. In the TiO2 NP-mediated inflammatory response, TLR 4 acted as the signaling receptor without protein complex of LPS, LBP and CD 14. The results suggested that character of TiO2 NPs might be similar to the complex of LPS, LBP and CD 14. These results are important for development of safer nanomaterials.

  5. Nonactivated titanium-dioxide nanoparticles promote the growth of Chlamydia trachomatis and decrease the antimicrobial activity of silver nanoparticles.

    Science.gov (United States)

    Bogdanov, A; Janovák, L; Lantos, I; Endrész, V; Sebők, D; Szabó, T; Dékány, I; Deák, J; Rázga, Z; Burián, K; Virok, D P

    2017-11-01

    Chlamydia trachomatis and herpes simplex virus (HSV) are the most prevalent bacterial and viral sexually transmitted infections. Due to the chronic nature of their infections, they are able to interact with titanium-dioxide (TiO 2 ) nanoparticles (NPs) applied as food additives or drug delivery vehicles. The aim of this study was to describe the interactions of these two prevalent pathogens with the TiO 2 NPs. Chlamydia trachomatis and HSV-2 were treated with nonactivated TiO 2 NPs, silver NPs and silver decorated TiO 2 NPs before infection of HeLa and Vero cells. Their intracellular growth was monitored by quantitative PCR. Unexpectedly, the TiO 2 NPs (100 μg ml -1 ) increased the growth of C. trachomatis by approximately fourfold, while the HSV-2 replication was not affected. Addition of TiO 2 to silver NPs decreased their antimicrobial activity against C. trachomatis up to 27·92-fold. In summary, nonactivated TiO 2 NPs could increase the replication of C. trachomatis and decrease the antimicrobial activity of silver NPs. The food industry or drug delivery use of TiO 2 NPs could enhance the growth of certain intracellular pathogens and potentially worsen disease symptoms, a feature that should be further investigated. © 2017 The Society for Applied Microbiology.

  6. Green oxidations: Titanium dioxide induced tandem oxidation coupling reactions

    OpenAIRE

    Jeena, Vineet; Robinson, Ross S

    2009-01-01

    Summary The application of titanium dioxide as an oxidant in tandem oxidation type processes is described. Under microwave irradiation, quinoxalines have been synthesized in good yields from the corresponding ?-hydroxyketones.

  7. Photo-conversion of CO2 using titanium dioxide: enhancements by plasmonic and co-catalytic nanoparticles

    International Nuclear Information System (INIS)

    Mankidy, Bijith D; Joseph, Babu; Gupta, Vinay K

    2013-01-01

    Converting carbon dioxide (CO 2 ) to hydrocarbons that can be used as fuels is beneficial from both environmental and economic points of view. In this study, nanoparticles are designed to enhance the photoreduction of CO 2 on a titanium dioxide (TiO 2 ) catalyst. An increase in catalytic activity is reported when silver (Ag), platinum (Pt) or bimetallic Ag–Pt and core–shell Ag@silica (SiO 2 ) nanoparticles are used with the TiO 2 semiconductor catalyst. Nanoparticles with different elemental composition or geometrical structure facilitate successive photo-excitation steps—generation, transport, storage and interfacial transfer of electrons and holes. Results show that while the addition of either type of nanoparticles augments product formation rates, bimetallic co-catalysts improve product selectivity. When both bimetallic co-catalysts and Ag@SiO 2 nanoparticles are used in combination, product yields are enhanced more than seven fold in comparison to native TiO 2 and high selectivity for methane (CH 4 ) is observed. When the bimetallic Ag–Pt co-catalysts are tuned, a selectivity of CH 4 of approximately 80%, as compared to 20% with only TiO 2 , can be achieved. (paper)

  8. Copper Nanoparticle Induced Cytotoxicity to Nitrifying Bacteria ...

    Science.gov (United States)

    With the inclusion of engineered nanomaterials in industrial processes and consumer products, wastewater treatments plants (WWTPs) will serve as a major sink for these emerging contaminants. Previous research has demonstrated that nanomaterials are potentially toxic to microbial communities utilized in biological wastewater treatment (BWT). Copper-based nanoparticles (CuNPs) are of particular interest based on their increasing use in wood treatment, paints, household products, coatings, and byproducts of semiconductor manufacturing. A critical step in BWT is nutrient removal via denitrification. This study examined the potential toxicity of bare and polyvinylpyrrolidone (PVP) coated CuO, and Cu2O nanoparticles, as well as Cu ions to microbial communities responsible for nitrogen removal in BWT. Inhibition was inferred from changes to the specific oxygen uptake rate (sOUR) in the absence and presence of Cu ions and CuNPs. X-ray absorption fine structure spectroscopy, with Linear Combination Fitting (LCF), was utilized to track changes to Cu speciation throughout exposure. Results indicate that the dissolution of Cu ions from CuNPs drive microbial inhibition. The presence of a PVP coating on CuNPs has little effect on inhibition. LCF fitting of the biomass combined with metal partitioning analysis supports the current hypothesis that Cu-induced cytotoxicity is primarily caused by reactive oxygen species formed from ionic Cu in solution via catalytic reaction inter

  9. Biocompatibility and antibacterial activity of nitrogen-doped titanium dioxide nanoparticles for use in dental resin formulations.

    Science.gov (United States)

    Zane, Andrew; Zuo, Ranfang; Villamena, Frederick A; Rockenbauer, Antal; Digeorge Foushee, Ann Marie; Flores, Kristin; Dutta, Prabir K; Nagy, Amber

    The addition of antibacterial functionality to dental resins presents an opportunity to extend their useful lifetime by reducing secondary caries caused by bacterial recolonization. In this study, the potential efficacy of nitrogen-doped titanium dioxide nanoparticles for this purpose was determined. Nitrogen doping was carried out to extend the ultraviolet absorbance into longer wavelength blue light for increased biocompatibility. Titanium dioxide nanoparticles (approximately 20-30 nm) were synthesized with and without nitrogen doping using a sol-gel method. Ultraviolet-Visible spectroscopy indicated a band of trap states, with increasing blue light absorbance as the concentration of the nitrogen dopant increased. Electron paramagnetic resonance measurements indicated the formation of superoxide and hydroxyl radicals upon particle exposure to visible light and oxygen. The particles were significantly toxic to Escherichia coli in a dose-dependent manner after a 1-hour exposure to a blue light source (480 nm). Intracellular reactive oxygen species assay demonstrated that the particles caused a stress response in human gingival epithelial cells when exposed to 1 hour of blue light, though this did not result in detectable release of cytokines. No decrease in cell viability was observed by water-soluble tetrazolium dye assay. The results show that nitrogen-doped titanium dioxide nanoparticles have antibacterial activity when exposed to blue light, and are biocompatible at these concentrations.

  10. Predator-induced reduction of freshwater carbon dioxide emissions

    Science.gov (United States)

    Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

    2013-03-01

    Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

  11. Titanium dioxide nanoparticles enhance inorganic arsenic bioavailability and methylation in two freshwater algae species.

    Science.gov (United States)

    Luo, Zhuanxi; Wang, Zhenhong; Yan, Yameng; Li, Jinli; Yan, Changzhou; Xing, Baoshan

    2018-07-01

    The effect of titanium dioxide nanoparticles (nano-TiO 2 ) on the bioaccumulation and biotransformation of arsenic (As) remains largely unknown. In this study, we exposed two freshwater algae (Microcystis aeruginosa and Scenedesmus obliquus) to inorganic As (arsenite and arsenate) with the aim of increasing our understanding on As bioaccumulation and methylation in the presence of nano-TiO 2 . Direct evidence from transmission electron microscope (TEM) images show that nano-TiO 2 (anatase) entered exposed algae. Thus, nano-TiO 2 as carriers boosted As accumulation and methylation in these two algae species, which varied between inorganic As speciation and algae species. Specifically, nano-TiO 2 could markedly enhance arsenate (As(V)) accumulation in M. aeruginosa and arsenite (As(III)) accumulation in S. obliquus. Similarly, we found evidence of higher As methylation activity in the M. aeruginosa of As(III) 2 mg L -1 nano-TiO 2 treatment. Although this was also true for the S. obliquus (As(V)) treatment, this species exhibited higher As methylation compared to M. aeruginosa, being more sensitive to As associated with nano-TiO 2 compared to M. aeruginosa. Due to changes in pH levels inside these exposed algae, As dissociation from nano-TiO 2 inside algal cells enhanced As methylation. Accordingly, the potential influence of nanoparticles on the bioaccumulation and biotransformation of their co-contaminants deserves more attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Titanium dioxide (TiO2) nanoparticles filled poly(d,l lactid acid) (PDLLA) matrix composites for bone tissue engineering

    NARCIS (Netherlands)

    Gerhardt, L.C.; Jell, G.M.R.; Boccaccini, A.R.

    2007-01-01

    Titanium dioxide (TiO2) nanoparticles were investigated for bone tissue engineering applications with regard to bioactivity and particle cytotoxicity. Composite films on the basis of poly(d,l lactid acid) (PDLLA) filled with 0, 5 and 30 wt% TiO2 nanoparticles were processed by solvent casting.

  13. Photoelectrochemical Sensors for the Rapid Detection of DNA Damage Induced by Some Nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Jamaluddin Ahmed

    2010-06-01

    Full Text Available Photoelectrochemcal sensors were developed for the rapid detection of oxidative DNA damage induced by titanium dioxide and polystyrene nanoparticles. Each sensor is a multilayer film prepared on a tin oxide nanoparticle electrode using layer- by-layer self assembly and is composed of separate layer of a photoelectrochemical indicator, DNA. The organic compound and heavy metals represent genotoxic chemicals leading two major damaging mechanisms, DNA adduct formation and DNA oxidation. The DNA damage is detected by monitoring the change of photocurrent of the indicator. In one sensor configuration, a DNA intercalator, Ru(bpy2 (dppz2+ [bpy=2, 2′ -bipyridine, dppz=dipyrido( 3, 2-a: 2′ 3′-c phenazine], was employed as the photoelectrochemical indicator. The damaged DNA on the sensor bound lesser Ru(bpy2 (dppz2+ than the intact DNA, resulting in a drop in photocurrent. In another configuration, ruthenium tris(bipyridine was used as the indicator and was immobilized on the electrode underneath the DNA layer. After oxidative damage, the DNA bases became more accessible to photoelectrochemical oxidation than the intact DNA, producing a rise in photocurrent. Both sensors displayed substantial photocurrent change after incubation in titanium dioxide / polystyrene solution in a time – dependent manner. According to the data, damage of the DNA film was completed in 1h in titanium dioxide / polystyrene solution. In addition, the titanium dioxide induced much more sever damage than polysterene. The results were verified independently by gel electrophoresis and UV-Vis absorbance experiments. The photoelectrochemical reaction can be employed as a new and inexpensive screening tool for the rapid assessment of the genotoxicity of existing and new chemicals.

  14. Photoelectrochemical sensors for the rapid detection of DNA damage Induced by some nanoparticles

    International Nuclear Information System (INIS)

    Ahmed, M.J.; Zhang, B.T.; Guo, L.H.

    2010-01-01

    Photoelectrochemical sensors were developed for the rapid detection of oxidative DNA damage induced by titanium dioxide and polystyrene nanoparticles. Each sensor is a multilayer film prepared on a tin oxide nanoparticle electrode using layer- by-layer self assembly and is composed of separate layer of a photoelectrochemical indicator, DNA. The organic compound and heavy metals represent genotoxic chemicals leading two major damaging mechanisms, DNA adduct formation and DNA oxidation. The DNA damage is detected by monitoring the change of photocurrent of the indicator. In one sensor configuration, a DNA intercalator, Ru(bpy)2 (dppz)2+ [bpy=2, 2' -bipyridine, dppz=dipyrido (3, 2-a: 2' 3'-c) phenazine], was employed as the photoelectrochemical indicator. The damaged DNA on the sensor bound lesser Ru(bpy)2 (dppz)2+ than the intact DNA, resulting in a drop in photocurrent. In another configuration, ruthenium tris(bipyridine) was used as the indicator and was immobilized on the electrode underneath the DNA layer. After oxidative damage, the DNA bases became more accessible to photoelectrochemical oxidation than the intact DNA, producing a rise in photocurrent. Both sensors displayed substantial photocurrent change after incubation in titanium dioxide / polystyrene solution in a time . dependent manner. According to the data, damage of the DNA film was completed in 1h in titanium dioxide / polystyrene solution. In addition, the titanium dioxide induced much more sever damage than polystyrene. The results were verified independently by gel electrophoresis and UV-Vis absorbance experiments. The photoelectrochemical reaction can be employed as a new and inexpensive screening tool for the rapid assessment of the genotoxicity of existing and new chemicals. (author)

  15. Mucus and microbiota as emerging players in gut nanotoxicology: The example of dietary silver and titanium dioxide nanoparticles.

    Science.gov (United States)

    Mercier-Bonin, Muriel; Despax, Bernard; Raynaud, Patrice; Houdeau, Eric; Thomas, Muriel

    2018-04-13

    Given the growing use of nanotechnology in many common consumer products, including foods, evaluation of the consequences of chronic exposure to nanoparticles in humans has become a major public health issue. The oral route of exposure has been poorly explored, despite the presence of a fraction of nanosized particles in certain food additives/supplements and the incorporation of such particles into packaging in contact with foods. After their ingestion, these nanoparticles pass through the digestive tract, where they may undergo physicochemical transformations, with consequences for the luminal environment, before crossing the epithelial barrier to reach the systemic compartment. In this review, we consider two examples, nanosilver and nanotitanium dioxide. Despite the specific features of these particles and the differences between them, both display a close relationship between physicochemical reactivity and bioavailability/biopersistence in the gastrointestinal tract. Few studies have focused on the interactions of nanoparticles of silver or titanium dioxide with the microbiota and mucus. However, the microbiota and mucus play key roles in intestinal homeostasis and host health and are undoubtedly involved in controlling the distribution of nanoparticles in the systemic compartment.

  16. Evaluation on Cartilage Morphology after Intra-Articular Injection of Titanium Dioxide Nanoparticles in Rats

    International Nuclear Information System (INIS)

    Wang, J.; Gao, Y.; Hou, Y.; Zhao, F.; Pu, F.; Liu, X.; Fan, Y.; Wu, Z.

    2012-01-01

    Nano scale wear particles would generate from orthopedic implants with nano scale surface topography because of residual stress. In this study, the effect of TiO 2 nanoparticles on articular cartilage was investigated by intra-articular injection in rats. Using contrast-enhanced high-resolution micro computed tomography (micro-CT) technology, the decreased thickness of articular cartilage in distal femur was determined at 1, 7, 14, and 30 days after nanoparticle exposure. A strong linear correlation (r=0.928, P 2 nanoparticles, cartilage thickness showed time-dependent decrease, and cartilage volume was decreased too. Further, the histopathological examination showed the edema chondrocyte and shrinked nucleus in the radial and calcified zone of cartilage. The ultrastructure of articular cartilage implied that the chondrocytes was degenerated, expressing as the condensed chromatin, the dilated endoplasmic reticulum, and the rich mitochondria. Even, the fragments of ruptured endoplasmic reticulum were observed in the cytoplasm of chondrocytes at postexposure day 30. Results indicate that potential damage of articular cartilage was induced by particles existed in knee joint and imply that the bio monitoring should be strengthened in patients with prostheses replacement.

  17. SU-F-T-663: Cerenkov Radiation Enhanced Radiotherapy with Titanium Dioxide Nanoparticle: A Monte Carlo Study

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B; Sajo, E [University of Massachusetts Lowell, Lowell, MA (United States); Ouyang, Z; Ngwa, W [University of Massachusetts Lowell, Lowell, MA (United States); Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: A recent publication has shown that by delivering titanium dioxide nanoparticles (titania) as a photosensitizer into tumors, Cerenkov radiation (CR) produced by radionuclides could be used for substantially boosting damage to cancer cells. The present work compares CR production by various clinically relevant radiation sources including internal radionuclides and external beam radiotherapy (EBRT), and provides preliminarily computational results of CR absorption by titania. Methods: 1) Geant4.10.1 was used to simulate ionizing radiation-induced CR production in a 1cm diameter spherical volume using external radiotherapy sources: Varian Clinac IX 6MV and Eldorado {sup 60}Co, both with 10*10 cm{sup 2} field size. In each case the volume was placed at the maximum dose depth (1.5cm for 6MV source and 0.5cm for {sup 60}Co). In addition, {sup 18}F, {sup 192}Ir and {sup 60}Co were simulated using Geant4 radioactive decay models as internal sources. Dose deposition and CR production spectra in 200nm-400nm range were calculated as it is the excitation range of titania. 2) Using 6MV external source, the absorption by titania was calculated via the track length of CR in the spherical volume. The nanoparticle concentration was varied from 0.25 to 5µg/g. Results: Among different radioactive sources, results showed that {sup 18}F induced the highest amount of CR per disintegration, but {sup 60}Co had the highest yield per unit dose. When compared with external sources, 6MV source was shown to be the most efficient for the the same delivered dose. Simulations indicated increased absorption for increasing concentrations, with up to 68% absorption of generated CR for 5µg/g titania concentration. Conclusion: The results demonstrate that 6MV beam is favored with a higher CR yield, compared to radionuclides, and that the use of higher concentrations of titania may increase photosensitization. From the findings, we propose that if sufficiently potent concentrations of

  18. Effect of cerium dioxide, titanium dioxide, silver, and gold nanoparticles on the activity of microbial communities intended in wastewater treatment

    International Nuclear Information System (INIS)

    García, Ana; Delgado, Lucía; Torà, Josep A.; Casals, Eudald; González, Edgar; Puntes, Víctor; Font, Xavier; Carrera, Julián; Sánchez, Antoni

    2012-01-01

    Highlights: ► Toxicity of TiO 2 , CeO 2 , Ag and Au nanoparticles (NP) has been studied. ► NP were synthesized in the lab and stabilized to prevent agglomeration. ► Toxicity was studied in all the communities used for the wastewater treatment. ► Heterotrophic, nitrifying and anaerobic organisms were studied for nanotoxicology. ► Au and TiO 2 NP were not toxic, but Ag and CeO 2 NP were inhibitory. - Abstract: Growth in production and use of nanoparticles (NPs) will result increased concentrations of these in industrial and urban wastewaters and, consequently, in wastewater-treatment facilities. The effect of this increase on the performance of the wastewater-treatment process has not been studied systematically and including all the microbial communities involved in wastewater treatment. The present work investigates, by using respiration tests and biogas-production analysis, the inhibitory effect of four different commonly used metal oxide (CeO 2 and TiO 2 ) and zero-valent metal (Ag and Au) nanoparticles on the activity of the most important microbial communities present in a modern wastewater-treatment plant. Specifically, the actions of ordinary heterotrophic organisms, ammonia oxidizing bacteria, and thermophilic and mesophilic anaerobic bacteria were tested in the presence and absence of the nanoparticles. In general, CeO 2 nanoparticles caused the greatest inhibition in biogas production (nearly 100%) and a strong inhibitory action of other biomasses; Ag nanoparticles caused an intermediate inhibition in biogas production (within 33–50%) and a slight inhibition in the action of other biomasses, and Au and TiO 2 nanoparticles caused only slight or no inhibition for all tested biomasses.

  19. Biodegradable starch/poly (vinyl alcohol) film reinforced with titanium dioxide nanoparticles

    Science.gov (United States)

    Hejri, Zahra; Seifkordi, Ali Akbar; Ahmadpour, Ali; Zebarjad, Seyed Mojtaba; Maskooki, Abdolmajid

    2013-10-01

    Biodegradable starch/poly (vinyl alcohol)/nano-titanium dioxide (ST/PVA/nano-TiO2) nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal properties were also studied in this paper. A general full factorial experimental approach was used to determine effective parameters on the mechanical properties of the prepared films. ST/PVA/TiO2 nanocomposites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of mechanical analysis show that ST/PVA films with higher contents of PVA have much better mechanical properties. In thermal analysis, it is found that the addition of TiO2 nanoparticles improves the thermal stability of the films. SEM micrographs, taken from the fracture surface of samples, illustrate that the addition of PVA makes the film softer and more flexible. The results of soil burial biodegradation indicate that the biodegradability of ST/PVA/TiO2 films strongly depends on the starch proportion in the film matrix. The degradation rate is increased by the addition of starch in the films.

  20. Transport of titanium dioxide nanoparticles in saturated porous media under various solution chemistry conditions

    International Nuclear Information System (INIS)

    Wang Yu; Gao Bin; Morales, Verónica L.; Tian Yuan; Wu Lei; Gao Jie; Bai Wei; Yang Liuyan

    2012-01-01

    Because of its wide applications, nanosized titanium dioxide may become a potential environmental risk to soil and groundwater system. It is therefore important to improve current understanding of the environmental fate and transport of titanium oxides nanoparticles (TONPs). In this work, the effect of solution chemistry (i.e., pH, ionic strength, and natural organic matter (NOM) concentration) on the deposition and transport of TONPs in saturated porous media was examined in detail. Laboratory columns packed with acid-cleaned quartz sand were used in the experiment as porous media. Transport experiments were conducted with various chemistry combinations, including four ionic strengths, three pH levels, and two NOM concentrations. The results showed that TONP mobility increased with increasing solution pH, but decreased with increasing solution ionic strength. It is also found that the presence of NOM in the system enhanced the mobility of TONPs in the saturated porous media. The Derjaguin–Landau–Verwey–Overbeek (DLVO) theory was used to justify the mobility trends observed in the experimental data. Predictions from the theory agreed excellently with the experimental data.

  1. Effects of Titanium Dioxide Nanoparticles on Red Clover and Its Rhizobial Symbiont.

    Science.gov (United States)

    Moll, Janine; Okupnik, Annette; Gogos, Alexander; Knauer, Katja; Bucheli, Thomas D; van der Heijden, Marcel G A; Widmer, Franco

    2016-01-01

    Titanium dioxide nanoparticles (TiO2 NPs) are in consideration to be used in plant protection products. Before these products can be placed on the market, ecotoxicological tests have to be performed. In this study, the nitrogen fixing bacterium Rhizobium trifolii and red clover were exposed to two TiO2 NPs, i.e., P25, E171 and a non-nanomaterial TiO2. Growth of both organisms individually and their symbiotic root nodulation were investigated in liquid and hydroponic systems. While 23 and 18 mg l-1 of E171 and non-nanomaterial TiO2 decreased the growth rate of R. trifolii by 43 and 23% respectively, P25 did not cause effects. Shoot length of red clover decreased between 41 and 62% for all tested TiO2 NPs. In 21% of the TiO2 NP treated plants, no nodules were found. At high concentrations certain TiO2 NPs impaired R. trifolii as well as red clover growth and their symbiosis in the hydroponic systems.

  2. Effects of Titanium Dioxide Nanoparticles on Red Clover and Its Rhizobial Symbiont.

    Directory of Open Access Journals (Sweden)

    Janine Moll

    Full Text Available Titanium dioxide nanoparticles (TiO2 NPs are in consideration to be used in plant protection products. Before these products can be placed on the market, ecotoxicological tests have to be performed. In this study, the nitrogen fixing bacterium Rhizobium trifolii and red clover were exposed to two TiO2 NPs, i.e., P25, E171 and a non-nanomaterial TiO2. Growth of both organisms individually and their symbiotic root nodulation were investigated in liquid and hydroponic systems. While 23 and 18 mg l-1 of E171 and non-nanomaterial TiO2 decreased the growth rate of R. trifolii by 43 and 23% respectively, P25 did not cause effects. Shoot length of red clover decreased between 41 and 62% for all tested TiO2 NPs. In 21% of the TiO2 NP treated plants, no nodules were found. At high concentrations certain TiO2 NPs impaired R. trifolii as well as red clover growth and their symbiosis in the hydroponic systems.

  3. Morphological and Physicochemical Characterization of Agglomerates of Titanium Dioxide Nanoparticles in Cell Culture Media

    Directory of Open Access Journals (Sweden)

    Verónica Freyre-Fonseca

    2016-01-01

    Full Text Available Titanium dioxide nanoparticles (TiO2 NP are possible carcinogenic materials (2B-IARC and their toxicity depends on shape, size, and electrical charge of primary NP and on the system formed by NP media. The aim of this work was to characterize agglomerates of three TiO2 NP by evaluating their morphometry, stability, and zeta potential (ζ in liquid media and their changes with time. Sizes of agglomerates by dynamic light scattering (DLS resulted to be 10–50 times larger than those obtained by digital image analysis (DIA given the charged zone around particles. Fractal dimension (FD was highest for agglomerates of spheres and belts in F12K, and in E171 in FBS media. E171 and belts increased FD with time. At time zero, using water as dispersant FD was larger for agglomerates of spheres than for of E171. Belts suspended in water had the smallest values of circularity (Ci which was approximately unchanged with time. All dispersions had ζ values around −30 mV at physiological pH (7.4 and dispersions of NP in water and FBS showed maximum stability (Turbiscan Lab analysis. Results help in understanding the complex NP geometry-size-stability relationships when performing in vivo and in vitro environmental-toxicity works and help in supporting decisions on the usage of TiO2 NP.

  4. Listeria monocytogenes behaviour in presence of non-UV-irradiated titanium dioxide nanoparticles.

    Directory of Open Access Journals (Sweden)

    Maria Grazia Ammendolia

    Full Text Available Listeria monocytogenes is the agent of listeriosis, a food-borne disease. It represents a serious problem for the food industry because of its environmental persistence mainly due to its ability to form biofilm on a variety of surfaces. Microrganisms attached on the surfaces are a potential source of contamination for environment and animals and humans. Titanium dioxide nanoparticles (TiO2 NPs are used in food industry in a variety of products and it was reported that daily exposure to these nanomaterials is very high. Anti-listerial activity of TiO2 NPs was investigated only with UV-irradiated nanomaterials, based on generation of reactive oxigen species (ROS with antibacterial effect after UV exposure. Since both Listeria monocytogenes and TiO2 NPs are veicolated with foods, this study explores the interaction between Listeria monocytogenes and non UV-irradiated TiO2 NPs, with special focus on biofilm formation and intestinal cell interaction. Scanning electron microscopy and quantitative measurements of biofilm mass indicate that NPs influence both production and structural architecture of listerial biofilm. Moreover, TiO2 NPs show to interfere with bacterial interaction to intestinal cells. Increased biofilm production due to TiO2 NPs exposure may favour bacterial survival in environment and its transmission to animal and human hosts.

  5. Toxic effects of the interaction of titanium dioxide nanoparticles with chemicals or physical factors

    Science.gov (United States)

    Liu, Kui; Lin, Xialu; Zhao, Jinshun

    2013-01-01

    Due to their chemical stability and nonallergic, nonirritant, and ultraviolet protective properties, titanium dioxide (TiO2) nanoparticles (NPs) have been widely used in industries such as electronics, optics, and material sciences, as well as architecture, medicine, and pharmacology. However, increasing concerns have been raised in regards to its ecotoxicity and toxicity on the aquatic environment as well as to humans. Although insights have been gained into the effects of TiO2 NPs on susceptible biological systems, there is still much ground to be covered, particularly in respect of our knowledge of the effects of the interaction of TiO2 NPs with other chemicals or physical factors. Studies suggest that interactions of TiO2 NPs with other chemicals or physical factors may result in an increase in toxicity or adverse effects. This review highlights recent progress in the study of the interactive effects of TiO2 NPs with other chemicals or physical factors. PMID:23901269

  6. Toxicokinetics of titanium dioxide (TiO2) nanoparticles after inhalation in rats.

    Science.gov (United States)

    Pujalté, Igor; Dieme, Denis; Haddad, Sami; Serventi, Alessandra Maria; Bouchard, Michèle

    2017-01-04

    This study focused on the generation of aerosols of titanium dioxide (TiO 2 ) nanoparticles (NPs) and their disposition kinetics in rats. Male Sprague-Dawley rats were exposed by inhalation to 15mg/m 3 of anatase TiO 2 NPs (∼20nm) during 6h. Rats were sacrificed at different time points over 14days following the onset of inhalation. Ti levels were quantified by ICP-MS in blood, tissues, and excreta. Oxidative damages were also monitored (MDA). Highest tissue levels of Ti were found in lungs; peak values were reached only at 48h followed by a progressive decrease over 14days, suggesting a persistence of NPs at the site-of-entry. Levels reached in blood, lymph nodes and other internal organs (including liver, kidney, spleen) were circa one order of magnitude lower than in lungs, but the profiles were indicative of a certain translocation to the systemic circulation. Large amounts were recovered in feces compared to urine, suggesting that inhaled NPs were eliminated mainly by mucociliary clearance and ingested. TiO 2 NPs also appeared to be partly transferred to olfactory bulbs and brain. MDA levels indicative of oxidative damage were significantly increased in lungs and blood at 24h but this was not clearly reflected at later times. Translocation and clearance rates of inhaled NPs under different realistic exposure conditions should be further documented. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Effect of titanium dioxide nanoparticles on zebrafish embryos and developing retina

    Directory of Open Access Journals (Sweden)

    Ya-Jie Wang

    2014-12-01

    Full Text Available AIM:To investigate the impact of titanium dioxide nanoparticles (TiO2 NPs on embryonic development and retinal neurogenesis. METHODS:The agglomeration and sedimentation of TiO2 NPs solutions at different dilutions were observed, and the ultraviolet-visible spectra of their supernatants were measured. Zebrafish embryos were experimentally exposed to TiO2 NPs until 72h postfertilization (hpf. The retinal neurogenesis and distribution of the microglia were analyzed by immunohistochemistry and whole mount in situ hybridization. RESULTS: The1 mg/L was determined to be an appropriate exposure dose. Embryos exposed to TiO2 NPs had a normal phenotype. The neurogenesis was initiated on time, and ganglion cells, cones and rods were well differentiated at 72 hpf. The expression of fms mRNA and the 4C4 antibody, which were specific to microglia in the central nervous system (CNS, closely resembled their endogenous profile. CONCLUSION:These data demonstrate that short-term exposure to TiO2 NPs at a low dose does not lead to delayed embryonic development or retinal neurotoxicity.

  8. Titanium Dioxide Nanoparticles as Radiosensitisers: An In vitro and Phantom-Based Study.

    Science.gov (United States)

    Youkhana, Esho Qasho; Feltis, Bryce; Blencowe, Anton; Geso, Moshi

    2017-01-01

    Objective: Radiosensitisation caused by titanium dioxide nanoparticles (TiO 2 -NPs) is investigated using phantoms (PRESAGE ® dosimeters) and in vitro using two types of cell lines, cultured human keratinocyte (HaCaT) and prostate cancer (DU145) cells. Methods: Anatase TiO 2 -NPs were synthesised, characterised and functionalised to allow dispersion in culture-medium for in vitro studies and halocarbons (PRESAGE ® chemical compositions). PRESAGE ® dosimeters were scanned with spectrophotometer to determine the radiation dose enhancement. Clonogenic and cell viability assays were employed to determine cells survival curves from which the dose enhancement levels "radiosensitisation" are deduced. Results: Comparable levels of radiosensitisation were observed in both phantoms and cells at kilovoltage ranges of x-ray energies (slightly higher in vitro) . Significant radiosensitisation (~67 %) of control was also noted in cells at megavoltage energies (commonly used in radiotherapy), compared to negligible levels detected by phantoms. This difference is attributed to biochemical effects, specifically the generation of reactive oxygen species (ROS) such as hydroxyl radicals ( • OH), which are only manifested in aqueous environments of cells and are non-existent in case of phantoms. Conclusions: This research shows that TiO 2 -NPs improve the efficiency of dose delivery, which has implications for future radiotherapy treatments. Literature shows that Ti 2 O 3 -NPs can be used as imaging agents hence with these findings renders these NPs as theranostic agents.

  9. Encapsulation of fish oil into hollow solid lipid micro- and nanoparticles using carbon dioxide.

    Science.gov (United States)

    Yang, Junsi; Ciftci, Ozan Nazim

    2017-09-15

    Fish oil was encapsulated in hollow solid lipid micro- and nanoparticles formed from fully hydrogenated soybean oil (FHSO) using a novel green method based on atomization of supercritical carbon dioxide (SC-CO 2 )-expanded lipid. The highest fish oil loading efficiency (97.5%, w/w) was achieved at 50%, w/w, initial fish oil concentration. All particles were spherical and in the dry free-flowing form; however, less smooth surface with wrinkles was observed when the initial fish oil concentration was increased up to 50%. With increasing initial fish oil concentration, melting point of the fish oil-loaded particles shifted to lower onset melting temperatures, and major polymorphic form transformed from α to β and/or β'. Oxidative stability of the loaded fish oil was significantly increased compared to the free fish oil (p<0.05). This innovative method forms free-flowing powder products that are easy-to-use solid fish oil formulation, which makes the handling and storage feasible and convenient. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Comparison of Oxidative Stresses Mediated by Different Crystalline Forms and Surface Modification of Titanium Dioxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Karim Samy El-Said

    2015-01-01

    Full Text Available Titanium dioxide nanoparticles (TiO2 NPs are manufactured worldwide for use in a wide range of applications. There are two common crystalline forms of TiO2 anatase and rutile with different physical and chemical characteristics. We previously demonstrated that an increased DNA damage response is mediated by anatase crystalline form compared to rutile. In the present study, we conjugated TiO2 NPs with polyethylene glycol (PEG in order to reduce the genotoxicity and we evaluated some oxidative stress parameters to obtain information on the cellular mechanisms of DNA damage that operate in response to TiO2 NPs different crystalline forms exposure in hepatocarcinoma cell lines (HepG2. Our results indicated a significant increase in oxidative stress mediated by the anatase form of TiO2 NPs compared to rutile form. On the other hand, PEG modified TiO2 NPs showed a significant decrease in oxidative stress as compared to TiO2 NPs. These data suggested that the genotoxic potential of TiO2 NPs varies with crystalline form and surface modification.

  11. Dose-dependent pulmonary response of well-dispersed titanium dioxide nanoparticles following intratracheal instillation

    International Nuclear Information System (INIS)

    Oyabu, Takako; Morimoto, Yasuo; Hirohashi, Masami; Horie, Masanori; Kambara, Tatsunori; Lee, Byeong Woo; Hashiba, Masayoshi; Mizuguchi, Yohei; Myojo, Toshihiko; Kuroda, Etsushi

    2013-01-01

    In order to investigate the relationship between pulmonary inflammation and particle clearance of nanoparticles, and also their dose dependency, we performed an instillation study of well-dispersed TiO 2 nanoparticles and examined the pulmonary inflammations, the particle clearance rate and histopathological changes. Wistar rats were intratracheally administered 0.1 mg (0.33 mg/kg), 0.2 mg (0.66 mg/kg), 1 mg (3.3 mg/kg), and 3 mg (10 mg/kg) of well-dispersed TiO 2 nanoparticles (diameter of agglomerates: 25 nm), and the pulmonary inflammation response and the amount of TiO 2 in the lung were determined from 3 days up to 12 months sequentially after the instillation. There were no increases of total cell or neutrophil counts in bronchoalveolar lavage fluid (BALF) in the 0.1 and the 0.2 mg-administered groups. On the other hand, mild infiltration of neutrophils was observed in the 1 and 3 mg-administered groups. Histopathological findings showed infiltration of neutrophils in the 1 and 3 mg-administered groups. Of special note, a granulomatous lesion including a local accumulation of TiO 2 was observed in the bronchioli-alveolar space in the 3 mg-administered group. The biological half times of the TiO 2 in the lung were 4.2, 4.4, 6.7, and 10.8 months in the 0.1, 0.2, 1, and 3 mg-administered groups, respectively. Neutrophil infiltration was observed as the particle clearance was delayed, suggesting that an excessive dose of TiO 2 nanoparticles may induce pulmonary inflammation and clearance delay.

  12. Dose-dependent pulmonary response of well-dispersed titanium dioxide nanoparticles following intratracheal instillation

    Energy Technology Data Exchange (ETDEWEB)

    Oyabu, Takako [Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Department of Environmental Health Engineering (Japan); Morimoto, Yasuo, E-mail: yasuom@med.uoeh-u.ac.jp; Hirohashi, Masami; Horie, Masanori; Kambara, Tatsunori [Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Department of Occupational Pneumology (Japan); Lee, Byeong Woo [Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Department of Environmental Health Engineering (Japan); Hashiba, Masayoshi [Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Department of Occupational Pneumology (Japan); Mizuguchi, Yohei; Myojo, Toshihiko [Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Department of Environmental Health Engineering (Japan); Kuroda, Etsushi [Osaka University, Laboratory of Vaccine Science, WPI Immunology Frontier Research Center (Japan)

    2013-04-15

    In order to investigate the relationship between pulmonary inflammation and particle clearance of nanoparticles, and also their dose dependency, we performed an instillation study of well-dispersed TiO{sub 2} nanoparticles and examined the pulmonary inflammations, the particle clearance rate and histopathological changes. Wistar rats were intratracheally administered 0.1 mg (0.33 mg/kg), 0.2 mg (0.66 mg/kg), 1 mg (3.3 mg/kg), and 3 mg (10 mg/kg) of well-dispersed TiO{sub 2} nanoparticles (diameter of agglomerates: 25 nm), and the pulmonary inflammation response and the amount of TiO{sub 2} in the lung were determined from 3 days up to 12 months sequentially after the instillation. There were no increases of total cell or neutrophil counts in bronchoalveolar lavage fluid (BALF) in the 0.1 and the 0.2 mg-administered groups. On the other hand, mild infiltration of neutrophils was observed in the 1 and 3 mg-administered groups. Histopathological findings showed infiltration of neutrophils in the 1 and 3 mg-administered groups. Of special note, a granulomatous lesion including a local accumulation of TiO{sub 2} was observed in the bronchioli-alveolar space in the 3 mg-administered group. The biological half times of the TiO{sub 2} in the lung were 4.2, 4.4, 6.7, and 10.8 months in the 0.1, 0.2, 1, and 3 mg-administered groups, respectively. Neutrophil infiltration was observed as the particle clearance was delayed, suggesting that an excessive dose of TiO{sub 2} nanoparticles may induce pulmonary inflammation and clearance delay.

  13. The effect of agglomeration state of silver and titanium dioxide nanoparticles on cellular response of HepG2, A549 and THP-1 cells.

    Science.gov (United States)

    Lankoff, Anna; Sandberg, Wiggo J; Wegierek-Ciuk, Aneta; Lisowska, Halina; Refsnes, Magne; Sartowska, Bożena; Schwarze, Per E; Meczynska-Wielgosz, Sylwia; Wojewodzka, Maria; Kruszewski, Marcin

    2012-02-05

    Nanoparticles (NPs) occurring in the environment rapidly agglomerate and form particles of larger diameters. The extent to which this abates the effects of NPs has not been clarified. The motivation of this study was to examine how the agglomeration/aggregation state of silver (20nm and 200nm) and titanium dioxide (21nm) nanoparticles may affect the kinetics of cellular binding/uptake and ability to induce cytotoxic responses in THP1, HepG2 and A549 cells. Cellular binding/uptake, metabolic activation and cell death were assessed by the SSC flow cytometry measurements, the MTT-test and the propidium iodide assay. The three types of particles were efficiently taken up by the cells, decreasing metabolic activation and increasing cell death in all the cell lines. The magnitude of the studied endpoints depended on the agglomeration/aggregation state of particles, their size, time-point and cell type. Among the three cell lines tested, A549 cells were the most sensitive to these particles in relation to cellular binding/uptake. HepG2 cells showed a tendency to be more sensitive in relation to metabolic activation. THP-1 cells were the most resistant to all three types of particles in relation to all endpoints tested. Our findings suggest that particle features such as size and agglomeration status as well as the type of cells may contribute to nanoparticles biological impact. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Challenges associated with performing environmental research on titanium dioxide nanoparticles in aquatic environments

    Science.gov (United States)

    There are challenges associated with performing research on titanium dioxide NPs in aquatic environments particularly marine systems. A critical focus for current titanium dioxide NP research in aquatic environments needs to be on optimizing methods for differentiating naturally...

  15. Effects of titanium dioxide (TiO2 ) nanoparticles on caribbean reef-building coral (Montastraea faveolata).

    Science.gov (United States)

    Jovanović, Boris; Guzmán, Héctor M

    2014-06-01

    Increased use of manufactured titanium dioxide nanoparticles (nano-TiO2 ) is causing a rise in their concentration in the aquatic environment, including coral reef ecosystems. Caribbean mountainous star coral (Montastraea faveolata) has frequently been used as a model species to study gene expression during stress and bleaching events. Specimens of M. faveolata were collected in Panama and exposed for 17 d to nano-TiO2 suspensions (0.1 mg L(-1) and 10 mg L(-1) ). Exposure to nano-TiO2 caused significant zooxanthellae expulsion in all the colonies, without mortality. Induction of the gene for heat-shock protein 70 (HSP70) was observed during an early stage of exposure (day 2), indicating acute stress. However, there was no statistical difference in HSP70 expression on day 7 or 17, indicating possible coral acclimation and recovery from stress. No other genes were significantly upregulated. Inductively coupled plasma mass spectrometry analysis revealed that nano-TiO2 was predominantly trapped and stored within the posterior layer of the coral fragment (burrowing sponges, bacterial and fungal mats). The bioconcentration factor in the posterior layer was close to 600 after exposure to 10 mg L(-1) of nano-TiO2 for 17 d. The transient increase in HSP70, expulsion of zooxanthellae, and bioaccumulation of nano-TiO2 in the microflora of the coral colony indicate the potential of such exposure to induce stress and possibly contribute to an overall decrease in coral populations. © 2014 SETAC.

  16. Toxicity of titanium dioxide nanoparticles: Effect of dose and time on biochemical disturbance, oxidative stress and genotoxicity in mice.

    Science.gov (United States)

    Rizk, Maha Z; Ali, Sanaa A; Hamed, Manal A; El-Rigal, Nagy Saba; Aly, Hanan F; Salah, Heba H

    2017-06-01

    The toxic impact of titanium dioxide nanoparticles (TiO 2 NPs) on human health is of prime importance owing to their wide uses in many commercial industries. In the present study, the effect of different doses and exposure time durations of TiO 2 NPs (21nm) inducing oxidative stress, biochemical disturbance, histological alteration and cytogenetic aberration in mice liver and bone marrow was investigated. Different doses of (TiO 2 NPs) (50, 250 and 500mg/kg body weight) were each daily intrapertioneally injected to mice for 7, 14 and 45days. Aspartate and alanine aminotransferases (AST &ALT), gamma glutamyl transpeptidase (GGT), total protein, total antioxidant capacity (TAC), malondialdehyde (MDA), glutathione (GSH), catalase (CAT) and nitric oxide (NO) levels were measured. The work was extended to evaluate the liver histopathological pattern and the chromosomal aberration in mice spinal cord bone marrow. The results revealed severe TiO 2 NPs toxicity in a dose and time dependent manner with positive correlation (r=0.98) for most investigated biochemical parameters. The same observation was noticed for the histological analysis. In case of cytogenetic study, chromosomal aberrations were demonstrated after injection of TiO 2 NPs with 500mg/kg b. wt. for 45days. In conclusion, the selected biochemical parameters and the liver architectures were influenced with dose and time of TiO 2 NPs toxicity, while the genetic disturbance started at the high dose of exposure and for long duration. Further studies are needed to fulfil the effect of TiO 2 NPs on pharmaceutical and nutritional applications. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. Tissue distribution and elimination after oral and intravenous administration of different titanium dioxide nanoparticles in rats

    Science.gov (United States)

    2014-01-01

    Objective The aim of this study was to obtain kinetic data that can be used in human risk assessment of titanium dioxide nanomaterials. Methods Tissue distribution and blood kinetics of various titanium dioxide nanoparticles (NM-100, NM-101, NM-102, NM-103, and NM-104), which differ with respect to primary particle size, crystalline form and hydrophobicity, were investigated in rats up to 90 days post-exposure after oral and intravenous administration of a single or five repeated doses. Results For the oral study, liver, spleen and mesenteric lymph nodes were selected as target tissues for titanium (Ti) analysis. Ti-levels in liver and spleen were above the detection limit only in some rats. Titanium could be detected at low levels in mesenteric lymph nodes. These results indicate that some minor absorption occurs in the gastrointestinal tract, but to a very limited extent. Both after single and repeated intravenous (IV) exposure, titanium rapidly distributed from the systemic circulation to all tissues evaluated (i.e. liver, spleen, kidney, lung, heart, brain, thymus, reproductive organs). Liver was identified as the main target tissue, followed by spleen and lung. Total recovery (expressed as % of nominal dose) for all four tested nanomaterials measured 24 h after single or repeated exposure ranged from 64-95% or 59-108% for male or female animals, respectively. During the 90 days post-exposure period, some decrease in Ti-levels was observed (mainly for NM-100 and NM-102) with a maximum relative decrease of 26%. This was also confirmed by the results of the kinetic analysis which revealed that for each of the investigated tissues the half-lifes were considerable (range 28–650 days, depending on the TiO2-particle and tissue investigated). Minor differences in kinetic profile were observed between the various particles, though these could not be clearly related to differences in primary particle size or hydrophobicity. Some indications were observed for an

  18. Assessment of the physico-chemical behavior of titanium dioxide nanoparticles in aquatic environments using multi-dimensional parameter testing

    International Nuclear Information System (INIS)

    Kammer, Frank von der; Ottofuelling, Stephanie; Hofmann, Thilo

    2010-01-01

    Assessment of the behavior and fate of engineered nanoparticles (ENPs) in natural aquatic media is crucial for the identification of environmentally critical properties of the ENPs. Here we present a methodology for testing the dispersion stability, ζ-potential and particle size of engineered nanoparticles as a function of pH and water composition. The results obtained from already widely used titanium dioxide nanoparticles (Evonik P25 and Hombikat UV-100) serve as a proof-of-concept for the proposed testing scheme. In most cases the behavior of the particles in the tested settings follows the expectations derived from classical DLVO theory for metal oxide particles with variable charge and an isoelectric point at around pH 5, but deviations also occur. Regardless of a 5-fold difference in BET specific surface area particles composed of the same core material behave in an overall comparable manner. The presented methodology can act as a basis for the development of standardised methods for comparing the behavior of different nanoparticles within aquatic systems. - The behavior of engineered nanoparticles in the aquatic environment can be elucidated using a multi-dimensional parameter set acquired by a semi automated experimental set-up.

  19. Mechanical and moisture barrier properties of titanium dioxide nanoparticles and halloysite nanotubes reinforced polylactic acid (PLA)

    International Nuclear Information System (INIS)

    Alberton, J; Martelli, S M; Soldi, V; Fakhouri, F M

    2014-01-01

    Polylactic acid (PLA) has been larger used in biomedical field due to its low toxicity and biodegradability. The aim of this study was to produce PLLA nanocomposites, by melt extrusion, containing Halloysite nanotubes (HNT) and/or titanium dioxide (TiO 2 ) nanoparticles. Immediately after drying, PLLA was mechanically homogenized with the nanofillers and then melt blended using a single screw extruder (L/D = 30) at a speed of 110 rpm, with three heating zones in which the following temperatures were maintained: 150, 150 and 160°C (AX Plasticos model AX14 LD30). The film samples were obtained by compression molding in a press with a temperature profile of 235 ± 5°C for 2.5 min, after pressing, films were cooled up to room temperature. The mechanical tests were performed according to ASTM D882-09 and the water vapor permeability (WVP) was measured according to ASTM E-96, in triplicate. The tensile properties indicated that the modulus was improved with increased TiO 2 content up to 1g/100g PLLA. The Young's modulus (YM) of the PLA was increased from 3047 MPa to 3222 MPa with the addition of 1g TiO 2 /100g PLLA. The tensile strength (TS) of films increases with the TiO 2 content. In both cases, the YM and TS are achieved at the 1% content of TiO 2 and is due to the reinforcing effect of nanoparticles. Pristine PLA showed a strain at break (SB) of 3.56%, while the SB of nanocomposites were significant lower, for instance the SB of composite containing 7.5 g HNT/100g PLLA was around 1.90 %. The WVP of samples was increased by increasing the nano filler content. It should be expected that an increase of nanofiller content would decrease the mass transfer of water molecules throughout the samples due to the increase in the way water molecules will have to cross to permeate the material. However, this was not observed. Therefore, this result can be explained considering the molecular structure of both fillers, which contain several hydroxyl groups in the surface

  20. A novel label-free voltammetric immunosensor for the detection of {alpha}-fetoprotein using functional titanium dioxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Liang Wenbin [Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yuan Ruo [Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)], E-mail: yuanruo@swu.edu.cn; Chai Yaqin; Li Yan; Zhuo Ying [Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2008-01-01

    A highly sensitive label-free voltammetric immunosensor was developed based on the functional titanium dioxide nanoparticles (PV-NTiP), which was prepared by capping 1,1'-bis-(2-phosphonoethyl)-4,4'-bipyridinium dibromide (PV) on the surface of the titanium dioxide nanoparticles (NTiP) with covalent attachment. The PV-NTiP has prominent biocompatibility, good electron transfer ability, primarily excellent adsorption, large specific surface area and positively charged environment. As a result, the negatively charged gold nanoparticles (NGP) could be adsorbed on the PV-NTiP modified electrode surface by electrostatic adsorption, and then to immobilize {alpha}-1-fetoprotein antibody (anti-AFP) for the assay of {alpha}-1-fetoprotein (AFP). The fabricated procedures and electrochemical behaviors of the immunosensor were characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and cyclic voltammetry (CV). The anti-AFP/NGP/PV-NTiP modified electrode was sensitive to AFP in linear relation between 1.25 and 200 ng/mL with the correlation coefficient of 0.9982, and the detection limit (S/N = 3) is 0.6 ng/mL under the optimal conditions. In addition, the proposed immunosensor exhibits good sensitivity, selectivity, stability and long-term maintenance of bioactivity and it may be used to immobilize other biomoleculars to develop biosensor for the detection of other antigens or biocompounds.

  1. Determining the efficiency of ZSM-5 zeolite impregnated with nanoparticles of titanium dioxide in the photocatalytic removal of styrene vapors

    Directory of Open Access Journals (Sweden)

    Mojtaba Nakhaei pour

    2017-03-01

    Full Text Available Introduction: Styrene monomer is a volatile organic compound that has many applications particularly in plastic, rubber and paint industries. According to the harmful effects of these compounds on human and environment, reducing and controling of them seem necessary. Therefore, in this study removal of styrene was investigated using photocatalytic process of titanium dioxide nanoparticles stabilized on ZSM-5. Methods: After stabilization of titanium dioxide nanoparticles on ZSM-5 zeolite, BET, SEM and XRD analysis were used to determine the characteristics of nanoparticles. Experiments were conducted at ambient temperature in laboratory scale. Concentration of produced styrene in the experiments was 50 and 300 ppm, and input flow rate was 1 l/min. Results: images and spectra obtained through XRD and SEM-EDAX showed that  nano-catalysts are well- stabilized. The results showed that by increasing of input concentration of styrene from 50 to 300 ppm, photocatalytic removal efficiency are reduced. Also, adsorption capacity of the catalyst bed in concentrations of 50 and 300 ppm was calculated 16.3 and19.4 mg/gr of adsorbent respectively. Conclusion: The results show that the use of hybrid bed can increase the removal efficiency of contaminants. And due to low cost of application of these systems compared to conventional methods, it is recommended that more comprehensive studies to be done regarding the optimization of the parameters affecting the process of photocatalytic removal.

  2. Laser induced synthesis of nanoparticles in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Kazakevich, P.V. [Wave Research Center, General Physics Institute of the Russian Academy of Sciences, 38 Vavilov street, 117942 Moscow (Russian Federation); Simakin, A.V. [Wave Research Center, General Physics Institute of the Russian Academy of Sciences, 38 Vavilov street, 117942 Moscow (Russian Federation); Voronov, V.V. [Wave Research Center, General Physics Institute of the Russian Academy of Sciences, 38 Vavilov street, 117942 Moscow (Russian Federation); Shafeev, G.A. [Wave Research Center, General Physics Institute of the Russian Academy of Sciences, 38 Vavilov street, 117942 Moscow (Russian Federation)]. E-mail: shafeev@kapella.gpi.ru

    2006-04-30

    The review of results on nanoparticles formation is presented under laser ablation of Ag, Au, and Cu-containing solid targets in liquid environments (H{sub 2}O, C{sub 2}H{sub 5}OH, C{sub 2}H{sub 4}Cl{sub 2}, etc.). X-ray diffractometry (XRD), UV-vis optical transmission spectrometry, and high resolution transmission electron microscopy (HRTEM) characterize the nanoparticles. The morphology of nanoparticles is studied as the function of both laser fluence and nature of the liquid. The possibility to control the shape of nanoparticles by ablation of an Au target by an interference pattern of two laser beams is demonstrated. Formation of alloyed Au-Ag and Ag-Cu nanoparticles is reported under laser exposure of a mixture of individual nanoparticles. The effect of internal segregation of brass nanoparticles is discussed due to their small lateral dimensions. The factors are discussed that determine the distribution function of particles size under laser ablation. The influence of laser parameters as well as the nature on the liquid on the properties of nanoparticles is elucidated.

  3. Nano-sized titanium dioxide-induced splenic toxicity: A biological pathway explored using microarray technology

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Lei [Medical College of Soochow University, Suzhou 215123 (China); Wang, Ling [Library of Soochow University, Suzhou 215123 (China); Sang, Xuezi; Zhao, Xiaoyang; Hong, Jie; Cheng, Shen; Yu, Xiaohong; Liu, Dong; Xu, Bingqing; Hu, Renping; Sun, Qingqing; Cheng, Jie; Cheng, Zhe; Gui, Suxin [Medical College of Soochow University, Suzhou 215123 (China); Hong, Fashui, E-mail: Hongfsh_cn@sina.com [Medical College of Soochow University, Suzhou 215123 (China)

    2014-08-15

    Highlights: • Exposure to TiO{sub 2} NPs could be accumulated in the spleen. • Exposure to TiO{sub 2} NPs caused spleen lesions in mice. • Exposure to TiO{sub 2} NPs resulted in immune dysfunction in mice. • Exposure to TiO{sub 2} NPs caused alteration of 1041 genes expression of known function in the spleen. - Abstract: Titanium dioxide nanoparticles (TiO{sub 2} NPs) have been widely used in various areas, and its potential toxicity has gained wide attention. However, the molecular mechanisms of multiple genes working together in the TiO{sub 2} NP-induced splenic injury are not well understood. In the present study, 2.5, 5, or 10 mg/kg body weight TiO{sub 2} NPs were administered to the mice by intragastric administration for 90 consecutive days, their immune capacity in the spleen as well as the gene-expressed characteristics in the mouse damaged spleen were investigated using microarray assay. The findings showed that with increased dose, TiO{sub 2} NP exposure resulted in the increases of spleen indices, immune dysfunction, and severe macrophage infiltration as well as apoptosis in the spleen. Importantly, microarray data showed significant alterations in the expressions of 1041 genes involved in immune/inflammatory responses, apoptosis, oxidative stress, stress responses, metabolic processes, ion transport, signal transduction, cell proliferation/division, cytoskeleton and translation in the 10 mg/kg TiO{sub 2} NP-exposed spleen. Specifically, Cyp2e1, Sod3, Mt1, Mt2, Atf4, Chac1, H2-k1, Cxcl13, Ccl24, Cd14, Lbp, Cd80, Cd86, Cd28, Il7r, Il12a, Cfd, and Fcnb may be potential biomarkers of spleen toxicity following exposure to TiO{sub 2} NPs.

  4. Responses of Pseudokirchneriella subcapitata and algal assembly to photocatalytic titanium dioxide nanoparticles

    Science.gov (United States)

    Metzler, David M.

    Development and use of nanomaterials has increased significantly over the past decade. This trend is expected to continue for the foreseeable future, which have led some to call this new industrial revolution. One aspect of these materials that make them special is their unique properties that are different from the bulk material. These unique properties have not been investigated to determine to what extent they will impact the environment. This work was undertaken to understand how nanoparticles could impact algae. For the determination of nanoparticle toxicity, dose-response experiments were run for similar sized Al2O3, TiO2, and SiO2. Additional, a wide range of nanoparticle sizes (d1) were tested at 100 and 1000 mg/L for Al2O3, TiO 2, and SiO2. Results of different nanoparticles and similar d1 dose-response data show increased toxicity with increased surface charge of the nanoparticle. Various d1 of Al2O 3 effect the population and chlorophyll a but not lipid peroxidation. Various d1 of SiO2 and TiO2 effect the population, chlorophyll a, and lipid peroxidation. Of all TiO2 d1 tested 42 nm had the greatest effect on population, chlorophyll a, and lipid peroxidation. The effect of light intensity, algal age, and body burden was examined. The body burden was adjusted by varying the initial algal cell population while keeping the nanoparticle concentration constant. Decreased body burden decreased the effect on population. The chlorophyll a and lipid peroxidation varied with the initial decreased with decreased body burden. This trend was reversed at low body burden, the chlorophyll a and lipid peroxidation increased 3 -- 4 times greater than control values. The algal cell age was controlled by the hydraulic retention time of the pre-exposure continuously stirred tank reactors. As the age of the algae increased the effect of population increased. At algae age great then 10 days the effect on population reminded constant. Titanium dioxide effect on chlorophyll a

  5. Influence of clay particles on the transport and retention of titanium dioxide nanoparticles in quartz sand.

    Science.gov (United States)

    Cai, Li; Tong, Meiping; Wang, Xueting; Kim, Hyunjung

    2014-07-01

    This study investigated the influence of two representative suspended clay particles, bentonite and kaolinite, on the transport of titanium dioxide nanoparticles (nTiO2) in saturated quartz sand in both NaCl (1 and 10 mM ionic strength) and CaCl2 solutions (0.1 and 1 mM ionic strength) at pH 7. The breakthrough curves of nTiO2 with bentonite or kaolinite were higher than those without the presence of clay particles in NaCl solutions, indicating that both types of clay particles increased nTiO2 transport in NaCl solutions. Moreover, the enhancement of nTiO2 transport was more significant when bentonite was present in nTiO2 suspensions relative to kaolinite. Similar to NaCl solutions, in CaCl2 solutions, the breakthrough curves of nTiO2 with bentonite were also higher than those without clay particles, while the breakthrough curves of nTiO2 with kaolinite were lower than those without clay particles. Clearly, in CaCl2 solutions, the presence of bentonite in suspensions increased nTiO2 transport, whereas, kaolinite decreased nTiO2 transport in quartz sand. The attachment of nTiO2 onto clay particles (both bentonite and kaolinite) were observed under all experimental conditions. The increased transport of nTiO2 in most experimental conditions (except for kaolinite in CaCl2 solutions) was attributed mainly to the clay-facilitated nTiO2 transport. The straining of larger nTiO2-kaolinite clusters yet contributed to the decreased transport (enhanced retention) of nTiO2 in divalent CaCl2 solutions when kaolinite particles were copresent in suspensions.

  6. Copper-doped titanium dioxide nanoparticles as dual-functional labels for fabrication of electrochemical immunosensors.

    Science.gov (United States)

    Zhang, Sen; Ma, Hongmin; Yan, Liangguo; Cao, Wei; Yan, Tao; Wei, Qin; Du, Bin

    2014-09-15

    Constructions of versatile electroactive labels are key issues in the development of electrochemical immunosensors. In this study, copper-doped titanium dioxide nanoparticle (Cu@TiO2) was synthesized and used as labels for fabrication of sandwich-type electrochemical immunosensors on glassy carbon electrode (GCE). Due to the presence of copper ions, Cu@TiO2 shows a strong response current when coupled to an electrode. The prepared nanocomposite also shows high electrocatalytic activity towards reduction of hydrogen peroxide (H2O2). The dual functionality of Cu@TiO2 enables the fabrication of immunosensor using different detection modes, that is, square wave voltammetry (SWV) or chronoamperometry (CA). While Cu@TiO2 was used as labels of secondary antibodies (Ab2), carboxyl functionalized graphene oxide (CFGO) was used as electrode materials to immobilize primary antibodies (Ab1). Using human immunoglobulin G (IgG) as a model analyte, the immunosensor shows high sensitivity, acceptable stability and good reproducibility for both detection modes. Under optimal conditions, a linear range from 0.1 pg/mL to 100 ng/mL with a detection limit of 0.052 pg/mL was obtained for SWV analysis. For CA analysis, a wider linear range from 0.01 pg/mL to 100 ng/mL and a lower detection limit of 0.0043 pg/mL were obtained. The proposed metal ion-based enzyme-free and noble metal-free immunosensor may have promising applications in clinical diagnoses and many other fields. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. In vivo and in vitro toxicological effects of titanium dioxide nanoparticles on small intestine

    Energy Technology Data Exchange (ETDEWEB)

    Tassinari, Roberta; La Rocca, Cinzia; Tait, Sabrina; De Berardis, Barbara; Ammendolia, Maria Grazia; Iosi, Francesca; Di Virgilio, Antonio; Martinelli, Andrea; Maranghi, Francesca, E-mail: francesca.maranghi@iss.it [Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome (Italy); Stecca, Laura [European Commission-Joint Research Centre, Institute for Health and Consumer Protection Chemical assessment and Testing Unit, Via E. Fermi, 2749I-21027 Ispra (Italy)

    2015-06-23

    In European Union, titanium dioxide (TiO{sub 2}) as bulk material is a food additive (E171) and - as nanoparticle (NP) - is used as a white pigment in several products (e.g. food, cosmetics, drugs). E171 contains approximately 36% of particles less than 100 nm in at least one dimension and TiO{sub 2} NP exposure is estimated fairly below 2.5 mg/person/day. The gastrointestinal tract is a route of entry for NPs, thus representing a potential target of effects. In in vivo study, the effects of TiO{sub 2} NP in adult rat small intestine have been evaluated by oral administration of 0 (CTRL), 1 and 2 mg/kg body weight per day - relevant to human dietary intake. Detailed quali/quantitative histopathological analyses were performed on CTRL and treated rat samples. Scanning electron microscopy (SEM) analysis was performed on small intestine. An in vitro study on Caco-2 cells was also used in order to evaluate the potential cytotoxic effects directly on enterocytes through the lactate dehydrogenase (LDH) assay. Suspensions of TiO{sub 2} NPs for in vitro and in vivo study were characterized by EM. Histomorphometrical data showed treatment-related changes of villus height and widths in male rats. Significantly different from CTRL decreased LDH levels in the medium were detected in vitro at 24h with 2.5, 5, 10 and 20 µg/cm{sup 2} levels of TiO{sub 2} NPs. SEM analysis showed no damaged areas. Overall the results showed that enterocytes may represent a target of TiO{sub 2} NP toxicity by direct exposure both in vivo and in vitro models.

  8. Influence of septic system wastewater treatment on titanium dioxide nanoparticle subsurface transport mechanisms.

    Science.gov (United States)

    Waller, Travis; Marcus, Ian M; Walker, Sharon L

    2018-06-04

    Engineered nanomaterials (ENMs) are commonly incorporated into food and consumer applications to enhance a specific product aspect (i.e., optical properties). Life cycle analyses revealed ENMs can be released from products during usage and reach wastewater treatment plants (WWTPs), with titanium dioxide (TiO 2 ) accounting for a large fraction. As such, food grade (FG) TiO 2 , a more common form of TiO 2 in wastewater, was used in this study. Nanomaterials in WWTPs have been well characterized, although the problematic septic system has been neglected. Elution and bioaccumulation of TiO 2 ENMs from WTTPs in downriver sediments and microorganisms has been observed; however, little is known about mechanisms governing the elution of FG TiO 2 from the septic drainage system. This study characterized the transport behavior and mechanisms of FG TiO 2 particles in porous media conditions after septic waste treatment. FG and industrial grade (IG) TiO 2 (more commonly studied) were introduced to septic tank effluent and low-ionic strength electrolyte solutions prior to column transport experiments. Results indicate that FG TiO 2 aggregate size (200-400 nm) remained consistent across solutions. Additionally, elution of FG and IG TiO 2 was greatest in septic effluent at the higher nanoparticle concentration (100 ppm). FG TiO 2 was well retained at the low (2 ppm) concentration in septic effluent, suggesting that particles that escape the septic system may still be retained in drainage field before reaching the groundwater system, although eluted particles are highly stabilized. Findings provide valuable insight into the significance of the solution environment at mediating differences observed between uniquely engineered nanomaterials. Graphical abstract.

  9. In vivo and in vitro toxicological effects of titanium dioxide nanoparticles on small intestine

    Science.gov (United States)

    Tassinari, Roberta; La Rocca, Cinzia; Stecca, Laura; Tait, Sabrina; De Berardis, Barbara; Ammendolia, Maria Grazia; Iosi, Francesca; Di Virgilio, Antonio; Martinelli, Andrea; Maranghi, Francesca

    2015-06-01

    In European Union, titanium dioxide (TiO2) as bulk material is a food additive (E171) and - as nanoparticle (NP) - is used as a white pigment in several products (e.g. food, cosmetics, drugs). E171 contains approximately 36% of particles less than 100 nm in at least one dimension and TiO2 NP exposure is estimated fairly below 2.5 mg/person/day. The gastrointestinal tract is a route of entry for NPs, thus representing a potential target of effects. In in vivo study, the effects of TiO2 NP in adult rat small intestine have been evaluated by oral administration of 0 (CTRL), 1 and 2 mg/kg body weight per day - relevant to human dietary intake. Detailed quali/quantitative histopathological analyses were performed on CTRL and treated rat samples. Scanning electron microscopy (SEM) analysis was performed on small intestine. An in vitro study on Caco-2 cells was also used in order to evaluate the potential cytotoxic effects directly on enterocytes through the lactate dehydrogenase (LDH) assay. Suspensions of TiO2 NPs for in vitro and in vivo study were characterized by EM. Histomorphometrical data showed treatment-related changes of villus height and widths in male rats. Significantly different from CTRL decreased LDH levels in the medium were detected in vitro at 24h with 2.5, 5, 10 and 20 µg/cm2 levels of TiO2 NPs. SEM analysis showed no damaged areas. Overall the results showed that enterocytes may represent a target of TiO2 NP toxicity by direct exposure both in vivo and in vitro models.

  10. Modification of metal bioaccumulation and toxicity in Daphnia magna by titanium dioxide nanoparticles

    International Nuclear Information System (INIS)

    Tan, Cheng; Wang, Wen-Xiong

    2014-01-01

    Titanium dioxide (TiO 2 ) nanoparticles are widely used in water treatments, yet their influences on other contaminants in the water are not well studied. In this study, the aqueous uptake, assimilation efficiency, and toxicity of two ionic metals (cadmium-Cd, and zinc-Zn) in a freshwater zooplankton, Daphnia magna, were investigated following 2 days pre-exposure to nano-TiO 2 . Pre-exposure to 1 mg/L nano-TiO 2 resulted in a significant increase in Cd and Zn uptake from the dissolved phase. After the nano-TiO 2 in the guts were cleared, the uptake rates immediately recovered to the normal levels. Concurrent measurements of reactive oxygen species (ROS) and metallothioneins (MTs) suggested that the increased metal uptake was mainly due to the increased number of binding sites provided by nano-TiO 2 presented in the guts. Consistently, pre-exposure to nano-TiO 2 increased the toxicity of aqueous Cd and Zn due to enhanced uptake. Our study provides the evidence that nano-TiO 2 in the guts of animals could increase the uptake and toxicity of other contaminants. -- Highlights: • Dissolved Cd and Zn uptake in daphnids increased significantly after nano-TiO 2 pre-exposure. • Aqueous toxicity of Cd and Zn also increased after nano-TiO 2 pre-exposure. • Dietary assimilation of Cd and Zn was not affected after nano-TiO 2 pre-exposure. • Metal uptake recovered to normal levels after nano-TiO 2 in the guts were removed. • Nano-TiO 2 in the guts of animals could increase the uptake and toxicity of other contaminants. -- Nano-TiO 2 accumulation in Daphnia magna facilitated the uptake and toxicity of metal contaminants

  11. Titanium dioxide nanoparticles: occupational exposure assessment in the photocatalytic paving production

    International Nuclear Information System (INIS)

    Spinazzè, Andrea; Cattaneo, Andrea; Limonta, Marina; Bollati, Valentina; Bertazzi, Pier Alberto; Cavallo, Domenico M.

    2016-01-01

    Limited data are available regarding occupational exposure assessment to nano-sized titanium dioxide (nano-TiO_2). The objective of this study is to assess the occupational exposure of workers engaged in the application of nano-TiO_2 onto concrete building materials, by means of a multi-metric approach (mean diameter, number, mass and surface area concentrations). The measurement design consists of the combined use of (i) direct-reading instruments to evaluate the total particle number concentrations relative to the background concentration and the mean size-dependent characteristics of particles (mean diameter and surface area concentration) and to estimate the 8-h time-weighted average (8-h TWA) exposure to nano-TiO_2 for workers involved in different working tasks; and (ii) filter-based air sampling, used for the determination of size-resolved particle mass concentrations. A further estimation was performed to obtain the mean 8-h TWA exposure values expressed as mass concentrations (µg nano-TiO_2/m"3). The multi-metric characterization of occupational exposure to nano-TiO_2 was significantly different both for different work environments and for each work task. Generally, workers were exposed to engineered nanoparticles (ENPs; <100 nm) mean levels lower than the recommended reference values and proposed occupational exposure limits (40,000 particle/cm"3; 300 µg/m"3) and relevant exposures to peak concentration were not likely to be expected. The estimated 8-h TWA exposure showed differences between the unexposed and exposed subjects. For these last, further differences were defined between operators involved in different work tasks. This study provides information on nano-TiO_2 number and mass concentration, size distribution, particles diameter and surface area concentrations, which were used to obtain work shift-averaged exposures.

  12. In vivo and in vitro toxicological effects of titanium dioxide nanoparticles on small intestine

    International Nuclear Information System (INIS)

    Tassinari, Roberta; La Rocca, Cinzia; Tait, Sabrina; De Berardis, Barbara; Ammendolia, Maria Grazia; Iosi, Francesca; Di Virgilio, Antonio; Martinelli, Andrea; Maranghi, Francesca; Stecca, Laura

    2014-01-01

    In European Union, titanium dioxide (TiO 2 ) as bulk material is a food additive (E171) and - as nanoparticle (NP) - is used as a white pigment in several products (e.g. food, cosmetics, drugs). E171 contains approximately 36% of particles less than 100 nm in at least one dimension and TiO 2 NP exposure is estimated fairly below 2.5 mg/person/day. The gastrointestinal tract is a route of entry for NPs, thus representing a potential target of effects. In in vivo study, the effects of TiO 2 NP in adult rat small intestine have been evaluated by oral administration of 0 (CTRL), 1 and 2 mg/kg body weight per day - relevant to human dietary intake. Detailed quali/quantitative histopathological analyses were performed on CTRL and treated rat samples. Scanning electron microscopy (SEM) analysis was performed on small intestine. An in vitro study on Caco-2 cells was also used in order to evaluate the potential cytotoxic effects directly on enterocytes through the lactate dehydrogenase (LDH) assay. Suspensions of TiO 2 NPs for in vitro and in vivo study were characterized by EM. Histomorphometrical data showed treatment-related changes of villus height and widths in male rats. Significantly different from CTRL decreased LDH levels in the medium were detected in vitro at 24h with 2.5, 5, 10 and 20 µg/cm 2 levels of TiO 2 NPs. SEM analysis showed no damaged areas. Overall the results showed that enterocytes may represent a target of TiO 2 NP toxicity by direct exposure both in vivo and in vitro models

  13. Titanium dioxide nanoparticles: occupational exposure assessment in the photocatalytic paving production

    Energy Technology Data Exchange (ETDEWEB)

    Spinazzè, Andrea, E-mail: andrea.spinazze@uninsubria.it; Cattaneo, Andrea; Limonta, Marina [Università degli studi dell’Insubria, Dipartimento di Scienza e Alta Tecnologia (Italy); Bollati, Valentina; Bertazzi, Pier Alberto [Università degli Studi di Milano, EPIGET-Epidemiology, Epigenetics and Toxicology Lab, Dipartimento di Scienze Cliniche e di Comunità (Italy); Cavallo, Domenico M. [Università degli studi dell’Insubria, Dipartimento di Scienza e Alta Tecnologia (Italy)

    2016-06-15

    Limited data are available regarding occupational exposure assessment to nano-sized titanium dioxide (nano-TiO{sub 2}). The objective of this study is to assess the occupational exposure of workers engaged in the application of nano-TiO{sub 2} onto concrete building materials, by means of a multi-metric approach (mean diameter, number, mass and surface area concentrations). The measurement design consists of the combined use of (i) direct-reading instruments to evaluate the total particle number concentrations relative to the background concentration and the mean size-dependent characteristics of particles (mean diameter and surface area concentration) and to estimate the 8-h time-weighted average (8-h TWA) exposure to nano-TiO{sub 2} for workers involved in different working tasks; and (ii) filter-based air sampling, used for the determination of size-resolved particle mass concentrations. A further estimation was performed to obtain the mean 8-h TWA exposure values expressed as mass concentrations (µg nano-TiO{sub 2}/m{sup 3}). The multi-metric characterization of occupational exposure to nano-TiO{sub 2} was significantly different both for different work environments and for each work task. Generally, workers were exposed to engineered nanoparticles (ENPs; <100 nm) mean levels lower than the recommended reference values and proposed occupational exposure limits (40,000 particle/cm{sup 3}; 300 µg/m{sup 3}) and relevant exposures to peak concentration were not likely to be expected. The estimated 8-h TWA exposure showed differences between the unexposed and exposed subjects. For these last, further differences were defined between operators involved in different work tasks. This study provides information on nano-TiO{sub 2} number and mass concentration, size distribution, particles diameter and surface area concentrations, which were used to obtain work shift-averaged exposures.

  14. Pulmotoxicological effects caused by long-term titanium dioxide nanoparticles exposure in mice

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Qingqing; Tan, Danning; Ze, Yuguan; Sang, Xuezi [Medical College of Soochow University, Suzhou 215123 (China); Liu, Xiaorun [Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009 (China); Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210009 (China); Gui, Suxin; Cheng, Zhe; Cheng, Jie; Hu, Renping; Gao, Guodong; Liu, Gan; Zhu, Min; Zhao, Xiaoyang; Sheng, Lei; Wang, Ling [Medical College of Soochow University, Suzhou 215123 (China); Tang, Meng, E-mail: tm@seu.edu.cn [Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009 (China); Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210009 (China); Hong, Fashui, E-mail: Hongfsh_cn@sina.com [Medical College of Soochow University, Suzhou 215123 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Exposure to TiO{sub 2} NPs could be significantly accumulated in the lung. Black-Right-Pointing-Pointer Exposure to TiO{sub 2} NPs caused pulmonary injury in mice. Black-Right-Pointing-Pointer Exposure to TiO{sub 2} NP promoted the expression of inflammatory cytokines in the lung. Black-Right-Pointing-Pointer Exposure to TiO{sub 2} NP caused ROS overproduction in the lung. - Abstract: Exposure to titanium dioxide nanoparticles (TiO{sub 2} NPs) has been demonstrated to result in pulmonary inflammation in animals; however, very little is known about the molecular mechanisms of pulmonary injury due to TiO{sub 2} NPs exposure. The aim of this study was to evaluate the oxidative stress and molecular mechanism associated with pulmonary inflammation in chronic lung toxicity caused by the intratracheal instillation of TiO{sub 2} NPs for 90 consecutive days in mice. Our findings suggest that TiO{sub 2} NPs are significantly accumulated in the lung, leading to an obvious increase in lung indices, inflammation and bleeding in the lung. Exposure to TiO{sub 2} NPs significantly increased the accumulation of reactive oxygen species and the level of lipid peroxidation, and decreased antioxidant capacity in the lung. Furthermore, TiO{sub 2} NPs exposure activated nuclear factor-{kappa}B, increased the levels of tumor necrosis factor-{alpha}, cyclooxygenase-2, heme oxygenase-1, interleukin-2, interleukin-4, interleukin-6, interleukin-8, interleukin-10, interleukin-18, interleukin-1{beta}, and CYP1A1 expression. However, TiO{sub 2} NPs exposure decreased NF-{kappa}B-inhibiting factor and heat shock protein 70 expression. Our results suggest that the generation of pulmonary inflammation caused by TiO{sub 2} NPs in mice is closely related to oxidative stress and the expression of inflammatory cytokines.

  15. No evidence of the genotoxic potential of gold, silver, zinc oxide and titanium dioxide nanoparticles in the SOS chromotest.

    Science.gov (United States)

    Nam, Sun-Hwa; Kim, Shin Woong; An, Youn-Joo

    2013-10-01

    Gold nanoparticles (Au NPs), silver nanoparticles (Ag NPs), zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO2 NPs) are widely used in cosmetic products such as preservatives, colorants and sunscreens. This study investigated the genotoxicity of Au NPs, Ag NPs, ZnO NPs and TiO2 NPs using the SOS chromotest with Escherichia coli PQ37. The maximum exposure concentrations for each nanoparticle were 3.23 mg l(-1) for Au NPs, 32.3 mg l(-1) for Ag NPs and 100 mg l(-1) for ZnO NPs and TiO2 NPs. Additionally, in order to compare the genotoxicity of nanoparticles and corresponding dissolved ions, the ions were assessed in the same way as nanoparticles. The genotoxicity of the titanium ion was not assessed because of the extremely low solubility of TiO2 NPs. Au NPs, Ag NPs, ZnO NPs, TiO2 NPs and ions of Au, Ag and Zn, in a range of tested concentrations, exerted no effects in the SOS chromotest, evidenced by maximum IF (IFmax) values of below 1.5 for all chemicals. Owing to the results, nanosized Au NPs, Ag NPs, ZnO NPs, TiO2 NPs and ions of Au, Ag and Zn are classified as non-genotoxic on the basis of the SOS chromotest used in this study. To the best of our knowledge, this is the first study to evaluate the genotoxicity of Au NPs, Ag NPs, ZnO NPs and TiO2 NPs using the SOS chromotest. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Synchrotron X-ray induced solution precipitation of nanoparticles

    CERN Document Server

    Lee, H J; Hwu, Y; Tsai, W L

    2003-01-01

    By irradiating a solution in electroless Ni deposition using synchrotron X-rays, Ni composite was found to nucleate homogeneously and eventually precipitate in the form of nanoparticles. The size of the nanoparticles precipitated is rather uniform (100-300 nm depending on the applied temperature). By the addition of an organic acid, well-dispersed nanoparticles could be effectively deposited on glass substrate. The hydrated electrons (e sub a sub q sup -), products of radiolysis of water molecules by synchrotron X-rays, may be responsible for the effective reduction of the metal ions, resulting in homogeneous nucleation and nanoparticle formation. Our results suggest that synchrotron X-ray can be used to induce solution precipitation of nanoparticles and therefore lead to a new method of producing nanostructured particles and coating.

  17. Aggregation in charged nanoparticles solutions induced by different interactions

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, S.; Kumar, Sugam; Aswal, V. K., E-mail: vkaswal@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 PSI Villigen (Switzerland)

    2016-05-23

    Small-angle neutron scattering (SANS) has been used to study the aggregation of anionic silica nanoparticles as induced through different interactions. The nanoparticle aggregation is induced by addition of salt (NaCl), cationic protein (lysozyme) and non-ionic surfactant (C12E10) employing different kind of interactions. The results show that the interaction in presence of salt can be explained using DLVO theory whereas non-DLVO forces play important role for interaction of nanoparticles with protein and surfactant. The presence of salt screens the repulsion between charged nanoparticles giving rise to a net attraction in the DLVO potential. On the other hand, strong electrostatic attraction between nanoparticle and oppositely charged protein leads to protein-mediated nanoparticle aggregation. In case of non-ionic surfactant, the relatively long-range attractive depletion interaction is found to be responsible for the particle aggregation. Interestingly, the completely different interactions lead to similar kind of aggregate morphology. The nanoparticle aggregates formed are found to have mass fractal nature having a fractal dimension (~2.5) consistent with diffusion limited type of fractal morphology in all three cases.

  18. The genotoxicity of titanium dioxide and cerium oxide nanoparticles in vitro

    Science.gov (United States)

    The use ofengineered nanoparticles in both current and future consumer products is steadily increasing. However, the health effects of exposure to these nanoparticles are not thoroughly understood. Recently, particular emphasis has been placed on particle characterization and the...

  19. The influence of adding modified zirconium oxide-titanium dioxide nano-particles on mechanical properties of orthodontic adhesive: an in vitro study

    OpenAIRE

    Felemban, Nayef H.; Ebrahim, Mohamed I.

    2017-01-01

    Background The purpose of this in-vitro study was to examine the effect of incorporating different concentrations of Zirconium oxide-Titanium dioxide (ZrO2-TiO2) nanoparticles, which can have antibacterial properties, on the mechanical properties of an orthodontic adhesive. Methods ZrO2-TiO2 (Zirconium oxide, HWNANO, Hongwu International Group Ltd, China) -Titanium dioxide, Nanoshell, USA) nanopowder were incorporated into orthodontic adhesive (Transbond XT, 3?M Unitek, Monrovia, USA) with di...

  20. Biomineralized diamond-like carbon films with incorporated titanium dioxide nanoparticles improved bioactivity properties and reduced biofilm formation.

    Science.gov (United States)

    Lopes, F S; Oliveira, J R; Milani, J; Oliveira, L D; Machado, J P B; Trava-Airoldi, V J; Lobo, A O; Marciano, F R

    2017-12-01

    Recently, the development of coatings to protect biomedical alloys from oxidation, passivation and to reduce the ability for a bacterial biofilm to form after implantation has emerged. Diamond-like carbon films are commonly used for implanted medical due to their physical and chemical characteristics, showing good interactions with the biological environment. However, these properties can be significantly improved when titanium dioxide nanoparticles are included, especially to enhance the bactericidal properties of the films. So far, the deposition of hydroxyapatite on the film surface has been studied in order to improve biocompatibility and bioactive behavior. Herein, we developed a new route to obtain a homogeneous and crystalline apatite coating on diamond-like carbon films grown on 304 biomedical stainless steel and evaluated its antibacterial effect. For this purpose, films containing two different concentrations of titanium dioxide (0.1 and 0.3g/L) were obtained by chemical vapor deposition. To obtain the apatite layer, the samples were soaked in simulated body fluid solution for up to 21days. The antibacterial activity of the films was evaluated by bacterial eradication tests using Staphylococcus aureus biofilm. Scanning electron microscopy, X-ray diffraction, Raman scattering spectroscopy, and goniometry showed that homogeneous, crystalline, and hydrophilic apatite films were formed independently of the titanium dioxide concentration. Interestingly, the diamond-like films containing titanium dioxide and hydroxyapatite reduced the biofilm formation compared to controls. A synergism between hydroxyapatite and titanium dioxide that provided an antimicrobial effect against opportunistic pathogens was clearly observed. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Physical-chemical properties of nanocomposites based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and titanium dioxide nanoparticles

    Science.gov (United States)

    Braga, Natália F.; da Silva, Ana Paula; Moraes Arantes, Tatiane; Lemes, Ana Paula; Cristovan, Fernando Henrique

    2018-01-01

    Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was reinforced with titanium dioxide (TiO2) in concentrations of 1.0%, 2.5% and 5.0% (m/m) to produce nanocomposites by the solvent casting technique. TiO2 was synthesized by a hydrothermal treatment to produce nanoparticles. The nanostructure of the nanoparticles was studied by x-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The XRD confirmed TiO2 crystalline nanoparticles, with a mixture of anatase and rutile phases. Through TEM analysis, the formation of TiO2 nanorod agglomerates with an average diameter and length of 40 and 12 nm, respectively, was observed. The thermal and mechanical properties of the pure PHBV and nanocomposite films were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis. The DSC analysis showed that the glass transition temperature decreased with the inclusion of TiO2 in the PHBV matrix in relation to pure PHBV. The results of biodegradation assays for the PHBV and nanocomposites in an aqueous medium and in soil showed morphological and structural changes for all samples, indicating a high biodegradation rate for this material. The most important conclusion is that the biodegradation of the PHBV was not affected by the addition of nanoparticles, thus enabling the use of nanocomposites in applications requiring biodegradable materials.

  2. Titanium dioxide induced cell damage: A proposed role of the carboxyl radical

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, Nicholas J.F. [Ecotoxicology and Stress Biology Research Centre, School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Jha, Awadhesh N. [Ecotoxicology and Stress Biology Research Centre, School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: a.jha@plymouth.ac.uk

    2009-01-15

    Titanium dioxide (TiO{sub 2}) nanoparticles have been shown to be genotoxic to cells exposed to ultraviolet A (UVA) radiation. Using the technique of electron spin resonance (ESR) spin trapping, we have confirmed that the primary damaging species produced on irradiation of TiO{sub 2} nanoparticles is the hydroxyl (OH) radical. We have applied this technique to TiO{sub 2}-treated fish and mammalian cells under in vitro conditions and observed the additional formation of carboxyl radical anions (CO{sub 2}{sup -}) and superoxide radical anions (O{sub 2}{sup -}). This novel finding suggests a hitherto unreported pathway for damage, involving primary generation of OH radicals in the cytoplasm, which react to give CO{sub 2}{sup -} radicals. The latter may then react with cellular oxygen to form O{sub 2}{sup -} and genotoxic hydrogen peroxide (H{sub 2}O{sub 2})

  3. Radiation-induced synthesis of gold, iron-oxide composite nanoparticles

    International Nuclear Information System (INIS)

    Seino, Satoshi; Yamamoto, Takao; Nakagawa, Takashi; Kinoshita, Takuya; Kojima, Takao; Taniguchi, Ryoichi; Okuda, Shuichi

    2007-01-01

    Composite nanoparticles consisting of magnetic iron oxide nanoparticles and gold nanoparticles were synthesized using gamma-rays or electron beam. Ionizing irradiation induces the generation of reducing species inside the aqueous solution, and gold ions are reduced to form metallic Au nanoparticles. The size of Au nanoparticles depended on the dose rate and the concentration of support iron oxide. The gold nanoparticles on iron oxide nanoparticles selectively adsorb biomolecules via Au-S bonding. By using magnetic property of the support iron oxide nanoparticles, the composite nanoparticles are expected as a new type of magnetic nanocarrier for biomedical applications. (author)

  4. Facilitated transport of titanium dioxide nanoparticles by humic substances in saturated porous media under acidic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ruichang [Chinese Academy of Sciences, Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science (China); Zhang, Haibo; Tu, Chen; Hu, Xuefeng; Li, Lianzhen [Chinese Academy of Sciences, Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (China); Luo, Yongming, E-mail: ymluo@yic.ac.cn; Christie, Peter [Chinese Academy of Sciences, Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science (China)

    2015-04-15

    The transport behavior of titanium dioxide nanoparticles (TiO{sub 2} NPs, 30 nm in diameter) was studied in well-defined porous media composed of clean quartz sand over a range of solution chemistry under acidic conditions. Transport of TiO{sub 2} NPs was dramatically enhanced by humic substances (HS) at acidic pH (4.0, 5.0 and 6.0), even at a low HS concentration of 0.5 mg L{sup −1}. Facilitated transport of TiO{sub 2} NPs was likely attributable to the increased stability of TiO{sub 2} NPs and repulsive interaction between TiO{sub 2} NPs and quartz sands due to the adsorbed HS. The mobility of TiO{sub 2} NPs was also increased with increasing pH from 4.0 to 6.0. Although transport of TiO{sub 2} NPs was insensitive to low ionic strength, it was significantly inhibited by high concentrations of NaCl and CaCl{sub 2}. In addition, calculated Derjaguin–Landau–Verwey–Overbeek (DLVO) interaction energy indicated that high energy barriers were responsible for the high mobility of TiO{sub 2} NPs, while the secondary energy minimum could play an important role in the retention of TiO{sub 2} NPs at 100 mmol L{sup −1} NaCl. Straining and gravitational settlement of larger TiO{sub 2} NPs aggregates at 1 mg L{sup −1} HS, pH 5.0, and 2 mmol L{sup −1} CaCl{sub 2} could be responsible for the significant retention even in the presence of high energy barriers. Moreover, more favorable interaction between approaching TiO{sub 2} NPs and TiO{sub 2} NPs that had been already deposited on the collector resulted in a ripening-shape breakthrough curve at 2 mmol L{sup −1} CaCl{sub 2}. Overall, a combination of mechanisms including DLVO-type force, straining, and physical filtration was involved in the retention of TiO{sub 2} NPs over the range of solution chemistry examined in this study.

  5. Immunotoxicity of silicon dioxide nanoparticles with different sizes and electrostatic charge.

    Science.gov (United States)

    Kim, Jae-Hyun; Kim, Cheol-Su; Ignacio, Rosa Mistica Coles; Kim, Dong-Heui; Sajo, Ma Easter Joy; Maeng, Eun Ho; Qi, Xu-Feng; Park, Seong-Eun; Kim, Yu-Ri; Kim, Meyoung-Kon; Lee, Kyu-Jae; Kim, Soo-Ki

    2014-01-01

    Silicon dioxide (SiO2) nanoparticles (NPs) have been widely used in the biomedical field, such as in drug delivery and gene therapy. However, little is known about the biological effects and potential hazards of SiO2. Herein, the colloidal SiO2 NPs with two different sizes (20 nm and 100 nm) and different charges (L-arginine modified: SiO2 (EN20[R]), SiO2 (EN100[R]); and negative: SiO2 (EN20[-]), SiO2 (EN100[-]) were orally administered (750 mg/kg/day) in female C57BL/6 mice for 14 days. Assessments of immunotoxicity include hematology profiling, reactive oxygen species generation and their antioxidant effect, stimulation assays for B- and T-lymphocytes, the activity of natural killer (NK) cells, and cytokine profiling. In vitro toxicity was also investigated in the RAW 264.7 cell line. When the cellularity of mouse spleen was evaluated, there was an overall decrease in the proliferation of B- and T-cells for all the groups fed with SiO2 NPs. Specifically, the SiO2 (EN20(-)) NPs showed the most pronounced reduction. In addition, the nitric oxide production and NK cell activity in SiO2 NP-fed mice were significantly suppressed. Moreover, there was a decrease in the serum concentration of inflammatory cytokines such as interleukin (IL)-1β, IL-12 (p70), IL-6, tumor necrosis factor-α, and interferon-γ. To elucidate the cytotoxicity mechanism of SiO2 in vivo, an in vitro study using the RAW 264.7 cell line was performed. Both the size and charge of SiO2 using murine macrophage RAW 264.7 cells decreased cell viability dose-dependently. Collectively, our data indicate that different sized and charged SiO2 NPs would cause differential immunotoxicity. Interestingly, the small-sized and negatively charged SiO2 NPs showed the most potent in vivo immunotoxicity by way of suppressing the proliferation of lymphocytes, depressing the killing activity of NK cells, and decreasing proinflammatory cytokine production, thus leading to immunosuppression.

  6. The recovery of 99Mo from solutions of irradiated Uranium using a column with nanoparticles of Titanium Dioxide

    International Nuclear Information System (INIS)

    Androne, G. E.; Petre, M.; Lazar, C. G.

    2016-01-01

    Molyibdenum-99 (T½ = 66.02 h) decays by beta emission to 99 Tcm (T½ = 6.02 h). The latter nuclide is used in many nuclear medicine applications. The 99 Mo is produced from irradiated high (HEU) or low (LEU) enriched uranium. In this work a sensitive and selective method for recovering Mo from uranium solution, using a column with titanium dioxide nanoparticles, is developed. The titanium dioxide (TiO 2 ) nanoparticles were synthesized via sol-gel method using titanium tetra-chloride as starting material and urea as a reacting medium. A 40 ml uranium solution containing 450 g/L uranyl nitrate, 1 M HNO 3 , and 4 mg Mo was loaded on a column containing 6 g of TiO 2 sorbent at 75°C. After loading, the column was washed with 1 M HNO 3 and H 2 O. Mo was stripped from the column with 0.1 M NaOH at 25°C. The ICP-MS results indicate that 80-95% of the initial mass of Mo was loaded on the column, and 90-94% of this quantity was recovered in the strip fraction. (authors)

  7. Carbon dioxide inhalation induces dose-dependent and age-related negative affectivity.

    Directory of Open Access Journals (Sweden)

    Eric J Griez

    Full Text Available BACKGROUND: Carbon dioxide inhalation is known to induce an emotion similar to spontaneous panic in Panic Disorder patients. The affective response to carbon dioxide in healthy subjects was not clearly characterized yet. METHODOLOGY/PRINCIPAL FINDINGS: Sixty-four healthy subjects underwent a double inhalation of four mixtures containing respectively 0, 9, 17.5 and 35% CO(2 in compressed air, following a double blind, cross-over, randomized design. Affective responses were assessed according to DSM IV criteria for panic, using an Electronic Visual Analogue Scale and the Panic Symptom List. It was demonstrated that carbon dioxide challenges induced a dose dependent negative affect (p<0.0001. This affect was semantically identical to the DSM IV definition of panic. Older individuals were subjectively less sensitive to Carbon Dioxide (p<0.05. CONCLUSIONS/SIGNIFICANCE: CO(2 induced affectivity may lay on a continuum with pathological panic attacks. Consistent with earlier suggestions that panic is a false biological alarm, the affective response to CO(2 may be part of a protective system triggered by suffocation and acute metabolic distress.

  8. Microbially Induced Precipitation of Gold(0) Nanoparticles.

    Science.gov (United States)

    Roh, Yu; Kang, Serku; Park, Bitna; Kim, Yumi

    2015-01-01

    The objectives of this study were to synthesize gold nanoparticles by biomineralization using metal-reducing bacteria and to characterize their mineralogical properties. The metal-reducing bacteria were able to reduce Au(III) to Au(0) with organic fatty acids as electron donors, as indicated by the color change of the culture solution from colorless gold ions to black precipitates at 25 degrees C. XRD, SEM- and TEM-EDS analyses of the precipitates showed that Au(0) was precipitated and formed at either the cell membrane or extracellularly. The Au(0) nanoparticles were about 200 nm in size and ball-shaped. Biomineralization for elemental Au(0) nanoparticle synthesis may be useful for the recovery of natural gold in natural environments.

  9. Carbon dioxide induces erratic respiratory responses in bipolar disorder.

    Science.gov (United States)

    Mackinnon, Dean F; Craighead, Brandie; Lorenz, Laura

    2009-01-01

    CO(2) respiration stimulates both anxiety and dyspnea ("air hunger") and has long been used to study panic vulnerability and respiratory control. High comorbidity with panic attacks suggests individuals with bipolar disorder may also mount a heightened anxiety response to CO(2). Moreover, problems in the arousal and modulation of appetites are central to the clinical syndromes of mania and depression; hence CO(2) may arouse an abnormal respiratory response to "air hunger". 72 individuals (34 bipolar I, 25 depressive and bipolar spectrum, 13 with no major affective diagnosis) breathed air and air with 5% CO(2) via facemask for up to 15 min each; subjective and respiratory responses were recorded. Nearly half the subjects diverged from the typical response to a fixed, mildly hypercapneic environment, which is to increase breathing acutely, and then maintain a hyperpneic plateau. The best predictors of an abnormal pattern were bipolar diagnosis and anxiety from air alone. 25 individuals had a panic response; panic responses from CO(2) were more likely in subjects with bipolar I compared to other subjects, however the best predictors of a panic response overall were anxiety from air alone and prior history of panic attacks. Heterogeneous sample, liberal definition of panic attack. Carbon dioxide produces abnormal respiratory and heightened anxiety responses among individuals with bipolar and depressive disorders. These may be due to deficits in emotional conditioning related to fear and appetite. Although preliminary, this work suggests a potentially useful test of a specific functional deficit in bipolar disorder.

  10. Transfection Agent Induced Nanoparticle Cell Loading

    Directory of Open Access Journals (Sweden)

    Karin Montet-Abou

    2005-07-01

    Full Text Available Loading cells with magnetic nanoparticles, and tracking their fate in vivo by high resolution MRI, is an attractive approach for enhancing the efficacy of cell-based therapies including those utilizing hematopoietic stem cells, neuroprogenitor cells, and T cells. The transfection agent (internalization agent assisted loading with the Feridex IV® nanoparticle is an attractive method of loading because of the low cost of materials, and possible low regulatory barriers for eventual clinical use. We therefore explored the interaction between Feridex IV® and three internalization agents protamine (PRO, polylysine (PLL, and lipofectamine (LFA. Feridex reacted with internalization agents to form aggregates, except when either the internalization agent or Feridex was present in large excess. When Jurkat T cells were incubated with Feridex/LFA or Feridex/PRO mixtures, and washed by centrifugation, nanoparticle aggregates co-purified with cells. With C17.2 cells large iron oxide particles adhered to the cell surface. At 30 μg/mL Feridex and 3 μg/mL LFA, internalization was largely mediated by LFA and was largely cytoplasmic. However, we found that the conditions used to label cells with Feridex and transfection agents need to be carefully selected to avoid the problems of surface adsorption and nanoparticle precipitation.

  11. Gestational exposure to titanium dioxide nanoparticles impairs the placentation through dysregulation of vascularization, proliferation and apoptosis in mice.

    Science.gov (United States)

    Zhang, Lu; Xie, Xingxing; Zhou, Yigang; Yu, Dainan; Deng, Yu; Ouyang, Jiexiu; Yang, Bei; Luo, Dan; Zhang, Dalei; Kuang, Haibin

    2018-01-01

    Titanium dioxide nanoparticles (TiO 2 NPs) have recently found applications in a wide variety of consumer goods. TiO 2 NPs exposure significantly increases fetal deformities and mortality. However, the potential toxicity of TiO 2 NPs on the growth and development of placenta has been rarely studied during mice pregnancy. The objective of this study was to investigate the effects of maternal exposure of TiO 2 NPs on the placentation. Mice were administered TiO 2 NPs by gavage at 0, 1 and 10 mg/kg/day from gestational day (GD) 1 to GD 13. Uteri and placentas from these mice were collected and counted the numbers of implanted and resorbed embryo and measured the placental weight on GD 13. Placental morphometry was observed by hematoxylin and eosin staining. The levels of Hand1, Esx1 , Eomes , Hand2 , Ascl2 and Fra1 mRNA were assessed by qRT-PCR. Uterine NK (uNK) cells were detected by using DBA lectin. Laminin immunohistochemical staining was to identify fetal vessels. Western blotting and transmission electron micrograph (TEM) were used to assess the apoptosis of placenta. No treatment-related difference was observed in the numbers of implanted and resorbed embryos and weight of placenta between the groups. However, 1 mg/kg/day TiO 2 NPs treatment significantly reduced the ratio of placenta/body weight on GD 13. The proportion of spongiotrophoblast in the 10 mg/kg/day dose group became higher than that in the control group, yet that of labyrinth was significantly lower in 10 mg/kg/day mice. The expression levels of Hand1 , Esx1 , Eomes , Hand2 , Ascl2 and Fra1 mRNA markedly decreased in TiO 2 NP treated placentas. Furthermore, TiO 2 NPs treatment impaired the formation of intricate networks of fetal vessels and reduced the number of uNK cells, and inhibited proliferation and induced apoptosis of placenta by nuclear pyknosis, the activation of caspase-3 and upregulation of Bax protein and downregulation of Bcl-2 protein on GD 13. Gestational exposure to TiO 2 NPs

  12. Ligand induced shape transformation of thorium dioxide nanocrystals.

    Science.gov (United States)

    Wang, Gaoxue; Batista, Enrique R; Yang, Ping

    2018-04-27

    Nanocrystals (NCs) with size and shape dependent properties are a thriving research field. Remarkable progress has been made in the controlled synthesis of NCs of stable elements in the past two decades; however, the knowledge of the NCs of actinide compounds has been considerably limited due the difficulties in handling them both experimentally and theoretically. Actinide compounds, especially actinide oxides, play a critical role in many stages of the nuclear fuel cycle. Recently, a non-aqueous surfactant assisted approach has been developed for the synthesis of actinide oxide NCs with different morphologies, but an understanding of its control factors is still missing to date. Herein we present a comprehensive study on the low index surfaces of thorium dioxide (ThO2) and their interactions with relevant surfactant ligands using density functional calculations. A systematic picture on the thermodynamic stability of ThO2 NCs of different sizes and shapes is obtained employing empirical models based on the calculated surface energies. It is found that bare ThO2 NCs prefer the octahedral shape terminated by (111) surfaces. Oleic acid displays selective adsorption on the (110) surface, leading to the shape transformation from octahedrons to nanorods. Other ligands such as acetylacetone, oleylamine, and trioctylphosphine oxide do not modify the equilibrium shape of ThO2 NCs. This work provides atomic level insights into the anisotropic growth of ThO2 NCs that was recently observed in experiments, and thus may contribute to the controlled synthesis of actinide oxide NCs with well-defined size and shape for future applications.

  13. Use of titanium dioxide nanoparticles biosynthesized by Bacillus mycoides in quantum dot sensitized solar cells.

    Science.gov (United States)

    Ordenes-Aenishanslins, Nicolás Alexis; Saona, Luis Alberto; Durán-Toro, Vicente María; Monrás, Juan Pablo; Bravo, Denisse Margarita; Pérez-Donoso, José Manuel

    2014-07-16

    One of the major challenges of nanotechnology during the last decade has been the development of new procedures to synthesize nanoparticles. In this context, biosynthetic methods have taken hold since they are simple, safe and eco-friendly. In this study, we report the biosynthesis of TiO2 nanoparticles by an environmental isolate of Bacillus mycoides, a poorly described Gram-positive bacterium able to form colonies with novel morphologies. This isolate was able to produce TiO2 nanoparticles at 37 ° C in the presence of titanyl hydroxide. Biosynthesized nanoparticles have anatase polymorphic structure, spherical morphology, polydisperse size (40-60 nm) and an organic shell as determined by UV-vis spectroscopy, TEM, DLS and FTIR, respectively. Also, conversely to chemically produced nanoparticles, biosynthesized TiO2 do not display phototoxicity. In order to design less expensive and greener solar cells, biosynthesized nanoparticles were evaluated in Quantum Dot Sensitized Solar Cells (QDSSCs) and compared with chemically produced TiO2 nanoparticles. Solar cell parameters such as short circuit current density (ISC) and open circuit voltage (VOC) revealed that biosynthesized TiO2 nanoparticles can mobilize electrons in QDSSCs similarly than chemically produced TiO2. Our results indicate that bacterial extracellular production of TiO2 nanoparticles at low temperatures represents a novel alternative for the construction of green solar cells.

  14. Influence of titanium dioxide nanoparticles on speciation and bioavailability of arsenite

    International Nuclear Information System (INIS)

    Sun Hongwen; Zhang Xuezhi; Zhang Zhiyan; Chen Yongsheng; Crittenden, John C.

    2009-01-01

    In this study, the influence of the co-existence of TiO 2 nanoparticles on the speciation of arsenite [As(III)] was studied by observing its adsorption and valence changing. Moreover, the influence of TiO 2 nanoparticles on the bioavailability of As(III) was examined by bioaccumulation test using carp (Cyprinus carpio). The results showed that TiO 2 nanoparticles have a significant adsorption capacity for As (III). Equilibrium was established within 30 min, with about 30% of the initial As (III) being adsorbed onto TiO 2 nanoparticles. Most of aqueous As (III) was oxidized to As(V) in the presence of TiO 2 nanoparticles under sunlight. The carp accumulated considerably more As in the presence of TiO 2 nanoparticles than in the absence of TiO 2 nanoparticles, and after 25-day exposure, As concentration in carp increased by 44%. Accumulation of As in viscera, gills and muscle of the carp was significantly enhanced by the presence of TiO 2 nanoparticles. - The co-existence of TiO 2 nanoparticles could change the speciation of arsenite by adsorption and photo-oxidation, and enhance its bioaccumulation to carp

  15. Influence of titanium dioxide nanoparticles on speciation and bioavailability of arsenite

    Energy Technology Data Exchange (ETDEWEB)

    Sun Hongwen [Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China)], E-mail: sunhongwen@nankai.edu.cn; Zhang Xuezhi [Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Department of Civil and Environmental Engineering, Arizona State University, Tempe, AZ 85287 (United States); Zhang Zhiyan [Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Chen Yongsheng; Crittenden, John C. [Department of Civil and Environmental Engineering, Arizona State University, Tempe, AZ 85287 (United States)

    2009-04-15

    In this study, the influence of the co-existence of TiO{sub 2} nanoparticles on the speciation of arsenite [As(III)] was studied by observing its adsorption and valence changing. Moreover, the influence of TiO{sub 2} nanoparticles on the bioavailability of As(III) was examined by bioaccumulation test using carp (Cyprinus carpio). The results showed that TiO{sub 2} nanoparticles have a significant adsorption capacity for As (III). Equilibrium was established within 30 min, with about 30% of the initial As (III) being adsorbed onto TiO{sub 2} nanoparticles. Most of aqueous As (III) was oxidized to As(V) in the presence of TiO{sub 2} nanoparticles under sunlight. The carp accumulated considerably more As in the presence of TiO{sub 2} nanoparticles than in the absence of TiO{sub 2} nanoparticles, and after 25-day exposure, As concentration in carp increased by 44%. Accumulation of As in viscera, gills and muscle of the carp was significantly enhanced by the presence of TiO{sub 2} nanoparticles. - The co-existence of TiO{sub 2} nanoparticles could change the speciation of arsenite by adsorption and photo-oxidation, and enhance its bioaccumulation to carp.

  16. PVDF nanofibers with silver nanoparticles and silver/titanium dioxide for antimicrobial applications;Eletrofiacao de nanofibras de PVDF com nanoparticulas de prata e de prata/dioxido de titanio para aplicacoes antimicrobiais

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Ligia M.M.; Olyveira, Gabriel M. de, E-mail: gmolyveira@yahoo.com.b, E-mail: ligialmmc@hotmail.co [Universidade Federal de Sao Carlos (PPGCEM/UFScar), SP (Brazil). Programa de Pos Graduacao em Ciencia e Engenharia de Materiais; Gregorio Filho, Rinaldo; Pessan, Luiz A., E-mail: pessan@ufscar.b, E-mail: gregorio@ufscar.b [Universidade Federal de Sao Carlos (UFScar), SP (Brazil)

    2009-07-01

    PVDF nanofibers with and without nanoparticles were produced by the method of electro spinning using dimethylformamide (DMF). Silver nitrate nanoparticles (0,5 and 2 wt %) and silver/titanium dioxide nanoparticles obtained by the reduction method (2 wt %) were synthesized and added to the PVDF solution to prepared nanofibers. The processes of electrospinning and film preparation using PVDF with the nanoparticles were compared. Silver/titanium dioxide nanoparticles were characterized with X-ray diffraction (XRD), Scanning electron microscopy (SEM) with EDX and x-ray photoelectron spectroscopy (XPS) to show silver/titanium dioxide nanoparticles. Nanofibers mats were characterized with SEM to study the effects of the addition of the nanoparticles on the morphology behavior and spectroscopy by Fourier transform infrared (FTIR) to analyze the crystalline phase of PVDF films. (author)

  17. Liquid Crystal Microlens Using Nanoparticle-Induced Vertical Alignment

    Directory of Open Access Journals (Sweden)

    Shug-June Hwang

    2015-01-01

    Full Text Available The nanoparticle-induced vertical alignment (NIVA of the nematic liquid crystals (LC is applied to achieve an adaptive flat LC microlens with hybrid-aligned nematic (HAN mode by dropping polyhedral oligomeric silsesquioxane (POSS nanoparticle solution on a homogeneous alignment layer. The vertical alignment induced by the POSS nanoparticles resulted in the formation of a hybrid-aligned LC layer with concentric nonuniform distribution of the refractive index in the planar LC cell, which subsequently played the role of the lens, even in the absence of any applied voltages. The dimensions of the concentric HAN structure significantly depend on the volume of the microdroplet and the POSS concentration. The focus effect of this flat microlens was observed while electrically controlling its focal length using the applied voltages from −50 mm to −90 mm.

  18. Ultrafast Hot Electron Induced Phase Transitions in Vanadium Dioxide

    Directory of Open Access Journals (Sweden)

    Haglund R. F.

    2013-03-01

    Full Text Available The Au/Cr/VO2/Si system was investigated in pump–probe experiments. Hot-electrons generated in the Au were found to penetrate into the underlying VO2 and couple with its lattice inducing a semiconductor-to-metal phase transition in ~2 picoseconds.

  19. Effect of Titanium Dioxide Nanoparticles on The Amount of Blood Cells and Liver Enzymes in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Rezaei Zarchi

    2011-11-01

    Full Text Available Introduction: Considering the development of nanotechnology and extensive use of nano-materials are in different fields of industry, it is necessary to investigate their destructive effects on biological systems. Titanium dioxide(TiO2 is used in the production of different dyes, cosmetics, ceramics, photocatalysts, water and sewage treatment and a lot of other products. In the present study, the effect of TiO2 on the number of blood cells and the activity of liver enzymes of rat was assessed. Methods: Concentrations of 50, 100 and 500 mg/Kg TiO2 nanoparticles (25 nm size in distilled water were administered orally to Wistar rats for 14 days and some blood factors were studied on the blood samples collected. Results: Results showed that TiO2 nanoparticles cause different changes in blood cells, and the changes were significant for some of them such as white blood cells (lymphocytes, monocytes, eosinophils and basophils. Decreased number of red blood cells and increased level of liver enzymes was also observed after the administration of different concentrations of TiO2, which proves the toxic effects of TiO2 on the body. Conclusion: Results of the present study proved the toxicity of TiO2 nanoparticles on the living organisms. So, further studies are recommended to predict TiO2 toxicity.

  20. The Potential Liver, Brain, and Embryo Toxicity of Titanium Dioxide Nanoparticles on Mice

    Science.gov (United States)

    Jia, Xiaochuan; Wang, Shuo; Zhou, Lei; Sun, Li

    2017-08-01

    Nanoscale titanium dioxide (nano-TiO2) has been widely used in industry and medicine. However, the safety of nano-TiO2 exposure remains unclear. In this study, we evaluated the liver, brain, and embryo toxicity and the underlying mechanism of nano-TiO2 using mice models. The results showed that titanium was distributed to and accumulated in the heart, brain, spleen, lung, and kidney of mice after intraperitoneal (i.p.) nano-TiO2 exposure, in a dose-dependent manner. The organ/body weight ratios of the heart, spleen, and kidney were significantly increased, and those of the brain and lung were decreased. High doses of nano-TiO2 significantly damaged the functions of liver and kidney and glucose and lipid metabolism, as showed in the blood biochemistry tests. Nano-TiO2 caused damages in mitochondria and apoptosis of hepatocytes, generation of reactive oxygen species, and expression disorders of protective genes in the liver of mice. We found ruptured and cracked nerve cells and inflammatory cell infiltration in the brain. We also found that the activities of constitutive nitric oxide synthases (cNOS), inducible NOS (iNOS), and acetylcholinesterase, and the levels of nitrous oxide and glutamic acid were changed in the brain after nano-TiO2 exposure. Ex vivo mouse embryo models exhibited developmental and genetic toxicity after high doses of nano-TiO2. The size of nano-TiO2 particles may affect toxicity, larger particles producing higher toxicity. In summary, nano-TiO2 exhibited toxicity in multiple organs in mice after exposure through i.p. injection and gavage. Our study may provide data for the assessment of the risk of nano-TiO2 exposure on human health.

  1. Low-debris, efficient laser-produced plasma extreme ultraviolet source by use of a regenerative liquid microjet target containing tin dioxide (SnO2) nanoparticles

    Science.gov (United States)

    Higashiguchi, Takeshi; Dojyo, Naoto; Hamada, Masaya; Sasaki, Wataru; Kubodera, Shoichi

    2006-05-01

    We demonstrated a low-debris, efficient laser-produced plasma extreme ultraviolet (EUV) source by use of a regenerative liquid microjet target containing tin-dioxide (SnO2) nanoparticles. By using a low SnO2 concentration (6%) solution and dual laser pulses for the plasma control, we observed the EUV conversion efficiency of 1.2% with undetectable debris.

  2. Low-debris, efficient laser-produced plasma extreme ultraviolet source by use of a regenerative liquid microjet target containing tin dioxide (SnO2) nanoparticles

    International Nuclear Information System (INIS)

    Higashiguchi, Takeshi; Dojyo, Naoto; Hamada, Masaya; Sasaki, Wataru; Kubodera, Shoichi

    2006-01-01

    We demonstrated a low-debris, efficient laser-produced plasma extreme ultraviolet (EUV) source by use of a regenerative liquid microjet target containing tin-dioxide (SnO 2 ) nanoparticles. By using a low SnO 2 concentration (6%) solution and dual laser pulses for the plasma control, we observed the EUV conversion efficiency of 1.2% with undetectable debris

  3. Errantum: Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins

    Directory of Open Access Journals (Sweden)

    Lai JCK

    2010-12-01

    Full Text Available Lai JCK, Ananthakrishnan G, Jandhyam S, et al. Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins. Int J Nanomedicine. 2010;5:715–723.The wrong image was used in Figure 5 on page 719.

  4. Cellular Interactions and Biological Responses to Titanium Dioxide Nanoparticles in HepG2 and BEAS-2B Cells: Role of Cell Culture Media

    Science.gov (United States)

    ABSTRACT We have shown previously that the composition of the biological medium used in vitro can affect the cellular interaction and biological response of titanium dioxide nanoparticles (nano-TiO2) in human lung epithelial cells. However, it is unclear if these effects are co...

  5. Pressure-induced weak ferromagnetism in uranium dioxide, UO2

    International Nuclear Information System (INIS)

    Sakai, H; Kato, H; Tokunaga, Y; Kambe, S; Walstedt, R E; Nakamura, A; Tateiwa, N; Kobayashi, T C

    2003-01-01

    The dc magnetization of insulating UO 2 under high pressure up to ∼1 GPa has been measured using a piston-cylinder cell. Pressure-induced weak ferromagnetism appeared at low pressure (∼0.2 GPa). Both the remanent magnetization and the coercive force increase as pressure increases. This weak ferromagnetism may come from spin canting or from uncompensated moments around grain boundaries

  6. Molecular Organization Induced Anisotropic Properties of Perylene - Silica Hybrid Nanoparticles.

    Science.gov (United States)

    Sriramulu, Deepa; Turaga, Shuvan Prashant; Bettiol, Andrew Anthony; Valiyaveettil, Suresh

    2017-08-10

    Optically active silica nanoparticles are interesting owing to high stability and easy accessibility. Unlike previous reports on dye loaded silica particles, here we address an important question on how optical properties are dependent on the aggregation-induced segregation of perylene molecules inside and outside the silica nanoparticles. Three differentially functionalized fluorescent perylene - silica hybrid nanoparticles are prepared from appropriate ratios of perylene derivatives and tetraethyl orthosilicate (TEOS) and investigated the structure property correlation (P-ST, P-NP and P-SF). The particles differ from each other on the distribution, organization and intermolecular interaction of perylene inside or outside the silica matrix. Structure and morphology of all hybrid nanoparticles were characterized using a range of techniques such as electron microscope, optical spectroscopic measurements and thermal analysis. The organizations of perylene in three different silica nanoparticles were explored using steady-state fluorescence, fluorescence anisotropy, lifetime measurements and solid state polarized spectroscopic studies. The interactions and changes in optical properties of the silica nanoparticles in presence of different amines were tested and quantified both in solution and in vapor phase using fluorescence quenching studies. The synthesized materials can be regenerated after washing with water and reused for sensing of amines.

  7. Nanoparticulate cerium dioxide and cerium dioxide-titanium dioxide composite thin films on glass by aerosol assisted chemical vapour deposition

    International Nuclear Information System (INIS)

    Qureshi, Uzma; Dunnill, Charles W.; Parkin, Ivan P.

    2009-01-01

    Two series of composite thin films were deposited on glass by aerosol assisted chemical vapour deposition (AACVD)-nanoparticulate cerium dioxide and nanoparticulate cerium dioxide embedded in a titanium dioxide matrix. The films were analysed by a range of techniques including UV-visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive analysis by X-rays. The AACVD prepared films showed the functional properties of photocatalysis and super-hydrophilicity. The CeO 2 nanoparticle thin films displaying photocatalysis and photo-induced hydrophilicity almost comparable to that of anatase titania.

  8. Effects of Titanium Dioxide Nanoparticles on the Synthesis of Fibroin in Silkworm (Bombyx mori).

    Science.gov (United States)

    Ni, Min; Li, FanChi; Tian, JiangHai; Hu, JingSheng; Zhang, Hua; Xu, KaiZun; Wang, BinBin; Li, YangYang; Shen, WeiDe; Li, Bing

    2015-08-01

    Silkworm (Bombyx mori) is an economically important insect, and its silk production capacity largely depends on its ability to synthesize fibroin. While breeding of B. mori varieties has been a key strategy to improve silk production, little improvement of B. mori silk production has been achieved to date. As a result, the development of sericulture economy has not progressed well, pointing to the need of new ways for improvement of B. mori silk production. Titanium dioxide nanoparticles (TiO2 NPs), a food additive widely used for livestock, have been shown to promote animal growth and increase the protein synthesis in animals. However, no studies on effect of TiO2 NPs on fibroin synthesis in B. mori have been available. In this study, the differential expression profiles of genes and proteins in the silk gland of B. mori fed without or with TiO2 NPs (5 μg ml(-1)) were analyzed and compared using digital gene expression (DGE), reverse transcription quantitative polymerase chain reaction (RT-qPCR), semi-qPCR, and Western blot analysis. The effects of TiO2 NPs feeding on the activity of proteases in the midgut and the synthesis and transportation of amino acids in hemolymph were also investigated. DGE analyses showed that among a total of 4,741 genes detected, 306 genes were differentially expressed after the TiO2 NPs feeding, of which 137 genes were upregulated whereas 169 genes were downregulated. 106 genes were shown to be involved in fibroin synthesis, of which 97 genes, including those encoding cuticular protein glycine-rich 10, serine protease inhibitor 28, aspartate aminotransferase, lysyl-tRNA synthetase, and splicing factor arginine/serine-rich 6, and silk gland factor-1 (SGF-1), were upregulated with the maximum induction of 8.52-folds, whereas nine genes, including those encoding aspartylglucosaminidase, the cathepsin L in Tribolium castaneum, and similar to SPRY domain-containing SOCS box protein 3, were downregulated with the maximum reduction of 8

  9. Resveratrol-loaded Nanoparticles Induce Antioxidant Activity against Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Jae-Hwan Kim

    2016-02-01

    Full Text Available Resveratrol acts as a free radical scavenger and a potent antioxidant in the inhibition of numerous reactive oxygen species (ROS. The function of resveratrol and resveratrol-loaded nanoparticles in protecting human lung cancer cells (A549 against hydrogen peroxide was investigated in this study. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS assay was performed to evaluate the antioxidant properties. Resveratrol had substantially high antioxidant capacity (trolox equivalent antioxidant capacity value compared to trolox and vitamin E since the concentration of resveratrol was more than 50 μM. Nanoparticles prepared from β-lactoglobulin (β-lg were successfully developed. The β-lg nanoparticle showed 60 to 146 nm diameter in size with negatively charged surface. Non-cytotoxicity was observed in Caco-2 cells treated with β-lg nanoparticles. Fluorescein isothiocynate-conjugated β-lg nanoparticles were identified into the cell membrane of Caco-2 cells, indicating that nanoparticles can be used as a delivery system. Hydrogen peroxide caused accumulation of ROS in a dose- and time-dependent manner. Resveratrol-loaded nanoparticles restored H2O2-induced ROS levels by induction of cellular uptake of resveratrol in A549 cells. Furthermore, resveratrol activated nuclear factor erythroid 2-related factor 2-Kelch ECH associating protein 1 (Nrf2-Keap1 signaling in A549 cells, thereby accumulation of Nrf2 abundance, as demonstrated by western blotting approach. Overall, these results may have implications for improvement of oxidative stress in treatment with nanoparticles as a biodegradable and non-toxic delivery carrier of bioactive compounds.

  10. Determination of Lead and Cadmium in cow’s Milk and Elimination by Using Titanium Dioxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Haniyeh Moallem Bandani

    2016-10-01

    Full Text Available Background and Objectives: Heavy metals such as cadmium and lead are the most important toxins spreading through various ways like water, soil, and air in nature and easily enter human food chain. It is essential to determine the cumulative and harmful effects of these metals in nutrients, especially in cow milk because it is a unique source of food for all ages and it contains both essential and nonessential trace elements. Materials and Methods: A total of 100 milk samples were directly collected from healthy cows in Zabol located on east of Iran. The samples were tested to determine lead and cadmium residues. The rates of the heavy metals were determined using a Rayleigh atomic absorption spectrum equipped with hollow cathode lamps (HCL at 283.3 nm for lead (Pb and at 228.8 nm for cadmium (Cd. By using the photo-catalytic titanium dioxide nanoparticles, these toxic metals were removed. Results: The mean ± SD of the concentration of lead and cadmium in raw milk were 9.175± 2.5 and 4.557 ± 1.081 ppb, respectively. Also, the P-values of Kalmogorov– Smiranov test for lead and cadmium were respectively 0.057 ppb (P>0.05 and 0.435 ppb (P>0.05. TiO2 nanoparticles were used to eliminate and remove lead and cadmium in milk samples. The results showed that there was a significant difference between lead and cadmium contents before and after adding TiO2 nanoparticles (P<0.05. Conclusions: According to results of this study, there was a very low amount of toxic metals. So, it seems that it is not necessary to use TiO2 in milk samples but these days it used frequently as an additive to some samples like milk to remove these pollutants. Keywords: lead, cadmium, milk, atomic absorption spectroscopy, TiO2 nanoparticles

  11. The challenges of testing metal and metal oxide nanoparticles in algal bioassays: titanium dioxide and gold nanoparticles as case studies

    DEFF Research Database (Denmark)

    Hartmann, Nanna Isabella Bloch; Engelbrekt, Christian; Zhang, Jingdong

    2013-01-01

    and TiO(2) nanoparticle aggregation/agglomeration increased as a function of concentration. Three biomass surrogate measuring techniques were evaluated (coulter counting, cell counting in haemocytometer, and fluorescence of pigment extracts) and out of these the fluorometric methods was found to be most...

  12. Cationic nanoparticles induce nanoscale disruption in living cell plasma membranes.

    Science.gov (United States)

    Chen, Jiumei; Hessler, Jessica A; Putchakayala, Krishna; Panama, Brian K; Khan, Damian P; Hong, Seungpyo; Mullen, Douglas G; Dimaggio, Stassi C; Som, Abhigyan; Tew, Gregory N; Lopatin, Anatoli N; Baker, James R; Holl, Mark M Banaszak; Orr, Bradford G

    2009-08-13

    It has long been recognized that cationic nanoparticles induce cell membrane permeability. Recently, it has been found that cationic nanoparticles induce the formation and/or growth of nanoscale holes in supported lipid bilayers. In this paper, we show that noncytotoxic concentrations of cationic nanoparticles induce 30-2000 pA currents in 293A (human embryonic kidney) and KB (human epidermoid carcinoma) cells, consistent with a nanoscale defect such as a single hole or group of holes in the cell membrane ranging from 1 to 350 nm(2) in total area. Other forms of nanoscale defects, including the nanoparticle porating agents adsorbing onto or intercalating into the lipid bilayer, are also consistent; although the size of the defect must increase to account for any reduction in ion conduction, as compared to a water channel. An individual defect forming event takes 1-100 ms, while membrane resealing may occur over tens of seconds. Patch-clamp data provide direct evidence for the formation of nanoscale defects in living cell membranes. The cationic polymer data are compared and contrasted with patch-clamp data obtained for an amphiphilic phenylene ethynylene antimicrobial oligomer (AMO-3), a small molecule that is proposed to make well-defined 3.4 nm holes in lipid bilayers. Here, we observe data that are consistent with AMO-3 making approximately 3 nm holes in living cell membranes.

  13. Titanium dioxide induces apoptotic cell death through reactive oxygen species-mediated Fas upregulation and Bax activation

    Directory of Open Access Journals (Sweden)

    Yoon TH

    2012-03-01

    Full Text Available Ki-Chun Yoo1, Chang-Hwan Yoon1, Dongwook Kwon2, Kyung-Hwan Hyun1, Soo Jung Woo1, Rae-Kwon Kim1, Eun-Jung Lim1, Yongjoon Suh1, Min-Jung Kim1, Tae Hyun Yoon2, Su-Jae Lee11Laboratory of Molecular Biochemistry, 2Laboratory of Nanoscale Characterization and Environmental Chemistry, Department of Chemistry, Hanyang University, Seoul, Republic of KoreaBackground: Titanium dioxide (TiO2 has been widely used in many areas, including biomedicine, cosmetics, and environmental engineering. Recently, it has become evident that some TiO2 particles have a considerable cytotoxic effect in normal human cells. However, the molecular basis for the cytotoxicity of TiO2 has yet to be defined.Methods and results: In this study, we demonstrated that combined treatment with TiO2 nanoparticles sized less than 100 nm and ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-dependent upregulation of Fas and conformational activation of Bax in normal human cells. Treatment with P25 TiO2 nanoparticles with a hydrodynamic size distribution centered around 70 nm (TiO2P25–70 together with ultraviolet A irradiation-induced caspase-dependent apoptotic cell death, accompanied by transcriptional upregulation of the death receptor, Fas, and conformational activation of Bax. In line with these results, knockdown of either Fas or Bax with specific siRNA significantly inhibited TiO2-induced apoptotic cell death. Moreover, inhibition of reactive oxygen species with an antioxidant, N-acetyl-L-cysteine, clearly suppressed upregulation of Fas, conformational activation of Bax, and subsequent apoptotic cell death in response to combination treatment using TiO2P25–70 and ultraviolet A irradiation.Conclusion: These results indicate that sub-100 nm sized TiO2 treatment under ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-mediated upregulation of the death receptor, Fas, and activation of the preapoptotic protein

  14. In situ titanium dioxide nanoparticles quantitative microscopy in cells and in C. elegans using nuclear microprobe analysis

    Energy Technology Data Exchange (ETDEWEB)

    Le Trequesser, Quentin [Université de Bordeaux, CENBG, Chemin du solarium, 33175 Gradignan (France); CNRS, UMR 5797, CENBG, Chemin du solarium, 33175 Gradignan (France); CNRS, Université de Bordeaux, ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac F-33608 (France); Saez, Gladys; Devès, Guillaume; Michelet, Claire; Barberet, Philippe [Université de Bordeaux, CENBG, Chemin du solarium, 33175 Gradignan (France); CNRS, UMR 5797, CENBG, Chemin du solarium, 33175 Gradignan (France); Delville, Marie-Hélène [CNRS, Université de Bordeaux, ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac F-33608 (France); Seznec, Hervé, E-mail: herve.seznec@cenbg.in2p3.fr [Université de Bordeaux, CENBG, Chemin du solarium, 33175 Gradignan (France); CNRS, UMR 5797, CENBG, Chemin du solarium, 33175 Gradignan (France)

    2014-12-15

    Detecting and tracking nanomaterials in biological systems is challenging and essential to understand the possible interactions with the living. In this context, in situ analyses were conducted on human skin cells and a multicellular organism (Caenorhabditiselegans) exposed to titanium dioxide nanoparticles (TiO{sub 2} NPs) using nuclear microprobe. Coupled to conventional methods, nuclear microprobe was found to be suitable for accurate description of chemical structure of biological systems and also for detection of native TiO{sub 2} NPs. The method presented herein opens the field to NPs exposure effects analyses and more generally to toxicological analyses assisted by nuclear microprobe. This method will show applications in key research areas where in situ imaging of chemical elements is essential.

  15. Removal of arsenic and methylene blue from water by granular activated carbon media impregnated with zirconium dioxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, Robert; Cooper, Anne Marie; Aymar, Kathryn; Jain, Arti [Environmental Technology, College of Technology and Innovation, Arizona State University, 6073 S. Backus Mall, Mesa, AZ 85212 (United States); Hristovski, Kiril, E-mail: Kiril.Hristovski@asu.edu [Environmental Technology, College of Technology and Innovation, Arizona State University, 6073 S. Backus Mall, Mesa, AZ 85212 (United States)

    2011-10-15

    Highlights: {yields} The morphology, content and distribution of ZrO{sub 2} nanoparticles inside the pores of GAC are affected by the type of GAC. {yields} Lignite ZrO{sub 2}-GAC exhibited Zr content of 12%, while bituminous based ZrO{sub 2}-GAC exhibited Zr content of 9.5%. {yields} The max. adsorption capacities under equilibrium conditions in 5 mM NaHCO{sub 3} buffered water matrix were {approx}8.6 As/g Zr and {approx}12.2 mg As/g Zr at pH = 7.6. {yields} The max. adsorption capacities under equilibrium conditions in NSF 53 Challenge water matrix while {approx}1.5 mg As/g Zr and {approx}3.2 mg As/g Zr at pH = 7.6. {yields} Introduction of nanoparticles did not impact the MB adsorption capacity of the lignite ZrO{sub 2}-GAC, while the one of bituminous ZrO{sub 2}-GAC decreased. - Abstract: This study investigated the effects of in situ ZrO{sub 2} nanoparticle formation on properties of granulated activated carbon (GAC) and their impacts on arsenic and organic co-contaminant removal. Bituminous and lignite based zirconium dioxide impregnated GAC (Zr-GAC) media were fabricated by hydrolysis of zirconium salt followed by annealing of the product at 400 {sup o}C in an inert environment. Media characterization suggested that GAC type does not affect the crystalline structure of the resulting ZrO{sub 2} nanoparticles, but does affect zirconium content of the media, nanoparticle morphology, nanoparticle distribution, and surface area of Zr-GAC. The arsenic removal performance of both media was compared using 5 mM NaHCO{sub 3} buffered ultrapure water and model groundwater containing competing ions, both with an initial arsenic C{sub 0} {approx} 120 {mu}g/L. Experimental outcomes suggested favorable adsorption energies and higher or similar adsorption capacities than commercially available or experimental adsorbents when compared on the basis of metal content. Short bed adsorber column tests showed that arsenic adsorption capacity decreases as a result of kinetics of

  16. Removal of arsenic and methylene blue from water by granular activated carbon media impregnated with zirconium dioxide nanoparticles

    International Nuclear Information System (INIS)

    Sandoval, Robert; Cooper, Anne Marie; Aymar, Kathryn; Jain, Arti; Hristovski, Kiril

    2011-01-01

    Highlights: → The morphology, content and distribution of ZrO 2 nanoparticles inside the pores of GAC are affected by the type of GAC. → Lignite ZrO 2 -GAC exhibited Zr content of 12%, while bituminous based ZrO 2 -GAC exhibited Zr content of 9.5%. → The max. adsorption capacities under equilibrium conditions in 5 mM NaHCO 3 buffered water matrix were ∼8.6 As/g Zr and ∼12.2 mg As/g Zr at pH = 7.6. → The max. adsorption capacities under equilibrium conditions in NSF 53 Challenge water matrix while ∼1.5 mg As/g Zr and ∼3.2 mg As/g Zr at pH = 7.6. → Introduction of nanoparticles did not impact the MB adsorption capacity of the lignite ZrO 2 -GAC, while the one of bituminous ZrO 2 -GAC decreased. - Abstract: This study investigated the effects of in situ ZrO 2 nanoparticle formation on properties of granulated activated carbon (GAC) and their impacts on arsenic and organic co-contaminant removal. Bituminous and lignite based zirconium dioxide impregnated GAC (Zr-GAC) media were fabricated by hydrolysis of zirconium salt followed by annealing of the product at 400 o C in an inert environment. Media characterization suggested that GAC type does not affect the crystalline structure of the resulting ZrO 2 nanoparticles, but does affect zirconium content of the media, nanoparticle morphology, nanoparticle distribution, and surface area of Zr-GAC. The arsenic removal performance of both media was compared using 5 mM NaHCO 3 buffered ultrapure water and model groundwater containing competing ions, both with an initial arsenic C 0 ∼ 120 μg/L. Experimental outcomes suggested favorable adsorption energies and higher or similar adsorption capacities than commercially available or experimental adsorbents when compared on the basis of metal content. Short bed adsorber column tests showed that arsenic adsorption capacity decreases as a result of kinetics of competing ions. Correlation between the properties of the media and arsenic and methylene blue removal

  17. Sustained release of nucleic acids from polymeric nanoparticles using microemulsion precipitation in supercritical carbon dioxide.

    Science.gov (United States)

    Ge, Jun; Jacobson, Gunilla B; Lobovkina, Tatsiana; Holmberg, Krister; Zare, Richard N

    2010-12-21

    A general approach for producing biodegradable nanoparticles for sustained nucleic acid release is presented. The nanoparticles are produced by precipitating a water-in-oil microemulsion in supercritical CO(2). The microemulsion consists of a transfer RNA aqueous solution (water phase), dichloromethane containing poly(l-lactic acid)-poly(ethylene glycol) (oil phase), the surfactant n-octyl β-D-glucopyranoside, and the cosurfactant n-butanol.

  18. Review of titanium dioxide nanoparticle phototoxicity: Developing a phototoxicity ratio to correct the endpoint values of toxicity tests

    Science.gov (United States)

    2015-01-01

    Abstract Titanium dioxide nanoparticles are photoactive and produce reactive oxygen species under natural sunlight. Reactive oxygen species can be detrimental to many organisms, causing oxidative damage, cell injury, and death. Most studies investigating TiO2 nanoparticle toxicity did not consider photoactivation and performed tests either in dark conditions or under artificial lighting that did not simulate natural irradiation. The present study summarizes the literature and derives a phototoxicity ratio between the results of nano‐titanium dioxide (nano‐TiO2) experiments conducted in the absence of sunlight and those conducted under solar or simulated solar radiation (SSR) for aquatic species. Therefore, the phototoxicity ratio can be used to correct endpoints of the toxicity tests with nano‐TiO2 that were performed in absence of sunlight. Such corrections also may be important for regulators and risk assessors when reviewing previously published data. A significant difference was observed between the phototoxicity ratios of 2 distinct groups: aquatic species belonging to order Cladocera, and all other aquatic species. Order Cladocera appeared very sensitive and prone to nano‐TiO2 phototoxicity. On average nano‐TiO2 was 20 times more toxic to non‐Cladocera and 1867 times more toxic to Cladocera (median values 3.3 and 24.7, respectively) after illumination. Both median value and 75% quartile of the phototoxicity ratio are chosen as the most practical values for the correction of endpoints of nano‐TiO2 toxicity tests that were performed in dark conditions, or in the absence of sunlight. Environ Toxicol Chem 2015;34:1070–1077. © 2015 The Author. Published by SETAC. PMID:25640001

  19. Nanoparticle dispersion in liquid metals by electromagnetically induced acoustic cavitation

    International Nuclear Information System (INIS)

    Kaldre, Imants; Bojarevičs, Andris; Grants, Ilmārs; Beinerts, Toms; Kalvāns, Matīss; Milgrāvis, Mikus; Gerbeth, Gunter

    2016-01-01

    Aim of this study is to investigate experimentally the effect of magnetically induced cavitation applied for the purpose of nanoparticle dispersion in liquid metals. The oscillating magnetic force due to the azimuthal induction currents and the axial magnetic field excites power ultrasound in the sample. If the fields are sufficiently high then it is possible to achieve the acoustic cavitation threshold in liquid metals. Cavitation bubble collapses are known to create microscale jets with a potential to break nanoparticle agglomerates and disperse them. The samples are solidified under the contactless ultrasonic treatment and later analyzed by electron microscopy and energy-dispersive X-ray spectroscopy (EDX). It is observed that SiC nanoparticles are dispersed in an aluminum magnesium alloy, whereas in tin the same particles remain agglomerated in micron-sized clusters despite a more intense cavitation.

  20. Integrated titanium dioxide (TiO_2) nanoparticles on interdigitated device electrodes (IDEs) for pH analysis

    International Nuclear Information System (INIS)

    Azizah, N.; Gopinath, Subash C. B.; Nadzirah, Sh.; Farehanim, M. A.; Fatin, M. F.; Ruslinda, A. R.; Hashim, U.; Arshad, M. K. Md.; Ayub, R. M.

    2016-01-01

    Titanium dioxide (TiO_2) nanoparticles based Interdigitated Device Electrodes (IDEs) Nanobiosensor device was developed for intracellular biochemical detection. Fabrication and characterization of pH sensors using IDE nanocoated with TiO_2 was studied in this paper. In this paper, a preliminary assessment of this intracellular sensor with electrical measurement under different pH levels. 3-aminopropyltriethoxysilane (APTES) was used to enhance the sensitivity of titanium dioxide layer as well as able to provide surface modification by undergoing protonation and deprotonation process. Different types of pH solution provide different resistivity and conductivity towards the surface. Base solution has the higher current compared to an acid solution. Amine and oxide functionalized TiO_2 based IDE exhibit pH-dependent could be understood in terms of the change in surface charge during protonation and deprotonation. The simple fabrication process, high sensitivity, and fast response of the TiO_2 based IDEs facilitate their applications in a wide range of areas. The small size of semiconductor TiO_2 based IDE for sensitive, label-free, real time detection of a wide range of biological species could be explored in vivo diagnostics and array-based screening.

  1. Multiple-diffusion flame synthesis of pure anatase and carbon-coated titanium dioxide nanoparticles

    KAUST Repository

    Memon, Nasir; Anjum, Dalaver H.; Chung, Suk-Ho

    2013-01-01

    A multi-element diffusion flame burner (MEDB) is useful in the study of flame synthesis of nanomaterials. Here, the growth of pure anatase and carbon-coated titanium dioxide (TiO2) using an MEDB is demonstrated. Hydrogen (H2), oxygen (O2), and argon

  2. Effect of Coating and Packaging Materials on Photocatalytic and Antimicrobial Activities of Titanium Dioxide Nanoparticles

    Science.gov (United States)

    Food safety or foodborne pathogen contamination is a major concern in food industry. Titanium dioxide (TiO2) is a photocatalyst and can inactivate a wide spectrum of microorganisms under UV illumination. There is significant interest in the development of TiO2-coated or –incorporated food packaging ...

  3. Cross talk between poly(ADP-ribose) polymerase 1 methylation and oxidative stress involved in the toxic effect of anatase titanium dioxide nanoparticles

    Science.gov (United States)

    Bai, Wenlin; Chen, Yujiao; Gao, Ai

    2015-01-01

    Given the tremendous growth in the application of titanium dioxide nanoparticles (TNPs), concerns about the potential health hazards of TNPs to humans have been raised. Poly(ADP-ribose) polymerase 1 (PARP-1), a highly conserved DNA-binding protein, is involved in many molecular and cellular processes. Limited data demonstrated that certain nanomaterials induced the aberrant hypermethylation of PARP-1. However, the mechanism involved in TNP-induced PARP-1 abnormal methylation has not been studied. A549 cells were incubated with anatase TNPs (22.1 nm) for 24 hours pretreatment with or without methyltransferase inhibitor 5-aza-2′-deoxycytidine and the reactive oxygen species (ROS) scavenger α-lipoic acid to assess the possible role of methylation and ROS in the toxic effect of TNPs. After TNPs characterization, a battery of assays was performed to evaluate the toxic effect of TNPs, PARP-1 methylation status, and oxidative damage. Results showed that TNPs decreased the cell viability in a dose-dependent manner, in accordance with the increase of lactate dehydrogenase activity, which indicated membrane damage of cells. Similar to the high level of PARP-1 methylation, the generation of ROS was significantly increased after exposure to TNPs for 24 hours. Furthermore, α-lipoic acid decreased TNP-induced ROS generation and then attenuated TNP-triggered PARP-1 hypermethylation. Meanwhile, 5-aza-2′-deoxycytidine simultaneously decreased the ROS generation induced by TNPs, resulting in the decline of PARP-1 methylation. In summary, TNPs triggered the aberrant hypermethylation of the PARP-1 promoter and there was a cross talk between oxidative stress and PARP-1 methylation in the toxic effect of TNPs. PMID:26366077

  4. Application of zirconium dioxide nanoparticle sorbent for the clean-up step in post-harvest pesticide residue analysis.

    Science.gov (United States)

    Uclés, Ana; Herrera López, Sonia; Dolores Hernando, Maria; Rosal, Roberto; Ferrer, Carmen; Fernández-Alba, Amadeo R

    2015-11-01

    The use of yttria-stabilized zirconium dioxide nanoparticles as d-SPE clean-up sorbent for a rapid and sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the determination of post-harvest fungicides (carbaryl, carbendazim, chlorpropham, diphenylamine, ethoxyquin, flutriafol, imazalil, iprodione, methomyl, myclobutanil, pirimiphos-methyl, prochloraz, pyrimethanil, thiabendazole, thiophanate-methyl and tolclofos-methyl) in orange and pear samples has been evaluated and validated. The sample preparation was a modification of the QuEChERS extraction method using yttria-stabilized zirconium dioxide and multi-walled carbon nanotubes (MWCNTs) nanoparticles as the solid phase extraction (d-SPE) clean-up sorbents prior to injecting the ten-fold diluted extracts into the LC system. By using the yttria-stabilized zirconium dioxide extraction method, more recoveries in the 70-120% range were obtained - thus this method was used for the validation. Quantification was carried out using a matrix-matched calibration curve which was linear in the 1-500 µg kg(-1) range for almost all the pesticides studied. The validated limit of quantification was 10 µg kg(-1) for most of the studied compounds, except chlorpropham, ethoxyquin and thiophanate-methyl. Pesticide recoveries at the 10 and 100 µg kg(-1) concentration levels were satisfactory, with values between 77% and 120% and relative standard deviations (RSD) lower than 10% (n=5). The developed method was applied for the determination of selected fungicides in 20 real orange and pear samples. Four different pesticide residues were detected in 10 of these commodities; 20% of the samples contained pesticide residues at a quantifiable level (equal to or above the LOQs) for at least one pesticide residue. The most frequently-detected pesticide residues were: carbendazim, thiabendazole and imazalil-all were below the MRL. The highest concentration found was imazalil at 1175 µg kg

  5. Thermally induced structural modifications and O2 trapping in highly porous silica nanoparticles

    International Nuclear Information System (INIS)

    Alessi, A.; Agnello, S.; Iovino, G.; Buscarino, G.; Melodia, E.G.; Cannas, M.; Gelardi, F.M.

    2014-01-01

    In this work we investigate by Raman spectroscopy the effect of isochronal (2 h) thermal treatments in air in the temperature range 200–1000 °C of amorphous silicon dioxide porous nanoparticles with diameters ranging from 5 up to 15 nm and specific surface 590–690 m 2 /g. Our results indicate that the amorphous structure changes similarly to other porous systems previously investigated, in fact superficial SiOH groups are removed, Si–O–Si linkages are created and the ring statistic is modified, furthermore these data evidence that the three membered rings do not contribute significantly to the Raman signal detected at about 495 cm −1 . In addition, after annealing at 900 and 1000 °C we noted the appearance of the O 2 emission at 1272 nm, absent in the not treated samples. The measure of the O 2 emission has been combined with electron paramagnetic resonance measurements of the γ irradiation induced HO · 2 radicals to investigate the O 2 content per mass unit of thin layers of silica. Our data reveal that the porous nanoparticles have a much lower ability to trap O 2 molecules per mass units than nonporous silica supporting a model by which O 2 trapping inside a surface layer of about 1 nm of silica is always limited. - Highlights: • O 2 emission and HO · 2 electron paramagnetic resonance signals are investigated. • Silica surface ability to trap O 2 molecules is explored by thermal treatments. • Raman study of thermally induced structural changes in porous silica nanoparticles. • Raman signal attributable to the three membered rings in silica

  6. Thermally induced structural modifications and O{sub 2} trapping in highly porous silica nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Alessi, A., E-mail: antonino.alessi@unipa.it; Agnello, S.; Iovino, G.; Buscarino, G.; Melodia, E.G.; Cannas, M.; Gelardi, F.M.

    2014-12-15

    In this work we investigate by Raman spectroscopy the effect of isochronal (2 h) thermal treatments in air in the temperature range 200–1000 °C of amorphous silicon dioxide porous nanoparticles with diameters ranging from 5 up to 15 nm and specific surface 590–690 m{sup 2}/g. Our results indicate that the amorphous structure changes similarly to other porous systems previously investigated, in fact superficial SiOH groups are removed, Si–O–Si linkages are created and the ring statistic is modified, furthermore these data evidence that the three membered rings do not contribute significantly to the Raman signal detected at about 495 cm{sup −1}. In addition, after annealing at 900 and 1000 °C we noted the appearance of the O{sub 2} emission at 1272 nm, absent in the not treated samples. The measure of the O{sub 2} emission has been combined with electron paramagnetic resonance measurements of the γ irradiation induced HO{sup ·}{sub 2} radicals to investigate the O{sub 2} content per mass unit of thin layers of silica. Our data reveal that the porous nanoparticles have a much lower ability to trap O{sub 2} molecules per mass units than nonporous silica supporting a model by which O{sub 2} trapping inside a surface layer of about 1 nm of silica is always limited. - Highlights: • O{sub 2} emission and HO{sup ·}{sub 2} electron paramagnetic resonance signals are investigated. • Silica surface ability to trap O{sub 2} molecules is explored by thermal treatments. • Raman study of thermally induced structural changes in porous silica nanoparticles. • Raman signal attributable to the three membered rings in silica.

  7. Hydrothermal synthesis of titanium dioxide nanoparticles: mosquitocidal potential and anticancer activity on human breast cancer cells (MCF-7).

    Science.gov (United States)

    Murugan, Kadarkarai; Dinesh, Devakumar; Kavithaa, Krishnamoorthy; Paulpandi, Manickam; Ponraj, Thondhi; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Subramaniam, Jayapal; Rajaganesh, Rajapandian; Wei, Hui; Kumar, Suresh; Nicoletti, Marcello; Benelli, Giovanni

    2016-03-01

    Mosquito vectors (Diptera: Culicidae) are responsible for transmission of serious diseases worldwide. Mosquito control is being enhanced in many areas, but there are significant challenges, including increasing resistance to insecticides and lack of alternative, cost-effective, and eco-friendly products. To deal with these crucial issues, recent emphasis has been placed on plant materials with mosquitocidal properties. Furthermore, cancers figure among the leading causes of morbidity and mortality worldwide, with approximately 14 million new cases and 8.2 million cancer-related deaths in 2012. It is expected that annual cancer cases will rise from 14 million in 2012 to 22 million within the next two decades. Nanotechnology is a promising field of research and is expected to give major innovation impulses in a variety of industrial sectors. In this study, we synthesized titanium dioxide (TiO2) nanoparticles using the hydrothermal method. Nanoparticles were subjected to different analysis including UV-Vis spectrophotometry, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), zeta potential, and energy-dispersive spectrometric (EDX). The synthesized TiO2 nanoparticles exhibited dose-dependent cytotoxicity against human breast cancer cells (MCF-7) and normal breast epithelial cells (HBL-100). After 24-h incubation, the inhibitory concentrations (IC50) were found to be 60 and 80 μg/mL on MCF-7 and normal HBL-100 cells, respectively. Induction of apoptosis was evidenced by Acridine Orange (AO)/ethidium bromide (EtBr) and 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) staining. In larvicidal and pupicidal experiments conducted against the primary dengue mosquito Aedes aegypti, LC50 values of nanoparticles were 4.02 ppm (larva I), 4.962 ppm (larva II), 5.671 ppm (larva III), 6.485 ppm (larva IV), and 7.527 ppm (pupa). Overall, our results suggested that TiO2 nanoparticles may be considered as

  8. Evaluation of the effects of titanium dioxide nanoparticles on cultured Rana catesbeiana tailfin tissue

    Directory of Open Access Journals (Sweden)

    S. Austin eHammond

    2013-11-01

    Full Text Available Nanoparticles (NPs, materials that have one dimension less than 100 nm, are used in manufacturing, health and food products, and consumer products including cosmetics, clothing and household appliances. Their utility to industry is derived from their high surface-area-to-volume ratios and physico-chemical properties distinct from their bulk counterparts, but the near-certainty that NPs will be released into the environment raises the possibility that they could present health risks to humans and wildlife. The thyroid hormones (THs, thyroxine and 3,3’,5-triiodothyronine (T3, are involved in development and metabolism in vertebrates including humans and frogs. Many of the processes of anuran metamorphosis are analogous to human post-embryonic development and disruption of TH action can have drastic effects. These shared features make the metamorphosis of anurans an excellent model for screening for endocrine disrupting chemicals (EDCs. We used the cultured tailfin (C-fin assay to examine the exposure effects of 0.1-10 nM (~8-800 ng/L of three types of ~20 nm TiO2 NPs (P25, M212, M262 and micron-sized TiO2 (μTiO2 ±10 nM T3. The actual Ti levels were 40.9 – 64.7% of the nominal value. Real-time quantitative polymerase chain reaction (QPCR was used to measure the relative amounts of mRNA transcripts encoding TH-responsive thyroid hormone receptors (thra and thrb and Rana larval keratin type I (rlk1, as well as the cellular stress-responsive heat shock protein 30 kDa (hsp30, superoxide dismutase (sod, and catalase (cat. The levels of the TH-responsive transcripts were largely unaffected by any form of TiO2. Some significant effects on stress-related transcripts were observed upon exposure to micron-sized TiO2, P25 and M212 while no effect was observed with M262 exposure. Therefore the risk of adversely affecting amphibian tissue by disrupting TH-signalling or inducing cellular stress is low for these compounds relative to other previously

  9. Nanosecond laser-induced synthesis of nanoparticles with tailorable magneticanisotropy

    International Nuclear Information System (INIS)

    Krishna, H.; Gangopadhyay, A.K.; Strader, J.; Kalyanaraman, R.

    2011-01-01

    Controlling the magnetic orientation of nanoparticles is important for many applications. Recently, it has been shown that single domain ferromagnetic hemispherical Co nanoparticles prepared by nanosecond laser-induced self-organization, show magnetic orientation that was related to the negative sign of the magnetostrictive coefficient λ S [J. Appl. Phys. v103, p073902, 2008]. Here we have extended this work to the Fe 50 Co 50 alloy, which has a positive λ S and Ni, which has a negative λ S . Patterned arrays of ferromagnetic nanoparticles of Fe 50 Co 50 , Ni, (and Co) were synthesized from their ultrathin metal films on SiO 2 substrate by nanosecond laser-induced self-organization. The morphology, nanostructure, and magnetic behavior of the nanoparticle arrays were investigated by a combination of electron microscopy, atomic force microscopy, and magnetic force microscopy techniques. Transmission electron microscopy investigations revealed a granular polycrystalline nanostructure, with the number of grains inside the nanoparticle increasing with their diameter. Magnetic force measurements showed that the magnetization direction of the hemispherical Co and Ni nanoparticles was predominantly out-of-plane while those for the Fe 50 Co 50 alloy was in the plane of the substrate. Finite element analysis was used to estimate the average residual strain in the nanoparticles, following laser processing. The difference in behavior is due to the dominating influence of magnetostrictive energy on the magnetization as a result of residual thermal strain following fast laser processing. Since λ S is negative for polycrystalline Co and Ni, and positive for Fe 50 Co 50 , the tensile residual strain forces the magnetization direction to out-of-plane and in-plane, respectively. This work demonstrates a cost-effective non-epitaxial technique for the synthesis of magnetic nanoparticles with tailored magnetization orientations. - Research Highlights: → Pulsed laser self

  10. Cuprous oxide nanoparticles selectively induce apoptosis of tumor cells

    Science.gov (United States)

    Wang, Ye; Zi, Xiao-Yuan; Su, Juan; Zhang, Hong-Xia; Zhang, Xin-Rong; Zhu, Hai-Ying; Li, Jian-Xiu; Yin, Meng; Yang, Feng; Hu, Yi-Ping

    2012-01-01

    In the rapid development of nanoscience and nanotechnology, many researchers have discovered that metal oxide nanoparticles have very useful pharmacological effects. Cuprous oxide nanoparticles (CONPs) can selectively induce apoptosis and suppress the proliferation of tumor cells, showing great potential as a clinical cancer therapy. Treatment with CONPs caused a G1/G0 cell cycle arrest in tumor cells. Furthermore, CONPs enclosed in vesicles entered, or were taken up by mitochondria, which damaged their membranes, thereby inducing apoptosis. CONPs can also produce reactive oxygen species (ROS) and initiate lipid peroxidation of the liposomal membrane, thereby regulating many signaling pathways and influencing the vital movements of cells. Our results demonstrate that CONPs have selective cytotoxicity towards tumor cells, and indicate that CONPs might be a potential nanomedicine for cancer therapy. PMID:22679374

  11. Bioaccumulation and physiological effects of copepods sp. (Eucyclop sp.) fed Chlorella ellipsoides exposed to titanium dioxide (TiO2) nanoparticles and lead (Pb2+).

    Science.gov (United States)

    Matouke, Moise M; Mustapha, Moshood

    2018-05-01

    The demand for manufactured products and the derivatives of nanomaterials and non essential metals continue to increase, and as a consequence their presence in fisheries and aquaculture has therefore become a major concern for the risks to which our environment is exposed. The bioaccumulation profile of binary compounds (Titanium dioxide nanoparticles and lead) and their effects on the feeding behaviour of copepods were assessed in a simplified food chain including, the freshwater alga Chlorella ellipsoides and the cyclopoids copepods sp. Our results indicated that Pb and TiO 2 NPs individually and mixed can be transferred from alga to copepods via dietary pathway. The highest bioconcentration factor (748.5) was recorded for Pb in the combined compounds (Pb15 + Ti16.5) μg L -1 and the highest BCF (5.57) recorded for TiO 2 NPs was found in TiO 2 NPs (16.5) alone. Ingestion and filtration rate decreased significantly (p  0.05) in both single and binary treatments. The results demonstrate that the co-exposure of TiO 2 NPs and Pb inhibit the ingestion and filtration of microalgae by cyclopoid copepods sp. and also induce increase of carbohydrate, lipid; GPx, GR and CAT due to stress. Copyright © 2018. Published by Elsevier B.V.

  12. Effects of human food grade titanium dioxide nanoparticle dietary exposure on Drosophila melanogaster survival, fecundity, pupation and expression of antioxidant genes.

    Science.gov (United States)

    Jovanović, Boris; Cvetković, Vladimir J; Mitrović, Tatjana Lj

    2016-02-01

    The fruitfly, Drosophila melanogaster was exposed to the human food grade of E171 titanium dioxide (TiO2). This is a special grade of TiO2 which is frequently omitted in nanotoxicology studies dealing with TiO2, yet it is the most relevant grade regarding oral exposure of humans. D. melanogaster larvae were exposed to 0.002 mg mL(-1), 0.02 mg mL(-1), 0.2 mg mL(-1), and 2 mg mL(-1) of TiO2 in feeding medium, and the survival, fecundity, pupation time, and expression of genes involved in oxidative stress response were monitored. TiO2 did not affect survival but significantly increased time to pupation (p TiO2 was present in a significant amount in larvae, but was not transferred to adults during metamorphosis. Two individuals with aberrant phenotype similar to previously described gold nanoparticles induced mutant phenotypes were detected in the group exposed to TiO2. In general, TiO2 showed little toxicity toward D. melanogaster at concentrations relevant to oral exposure of humans. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Investigating the growth mechanism and optical properties of carbon-coated titanium dioxide nanoparticles

    KAUST Repository

    Anjum, Dalaver H.; Memon, Nasir; Chung, Suk-Ho

    2013-01-01

    TiO2 nanoparticles (NPs) were prepared using flame synthesis and then characterized using transmission electron microscopy. We found that the flame method yields both crystalline TiO2 and amorphous TiO 2 NPs. TEM analysis revealed that only

  14. Titanium dioxide nanoparticles: synthesis, X-Ray line analysis and chemical composition study

    Energy Technology Data Exchange (ETDEWEB)

    Chenari, Hossein Mahmoudi, E-mail: mahmoudi_hossein@guilan.ac.ir, E-mail: h.mahmoudiph@gmail.com [University of Guilan, Rasht (Iran, Islamic Republic of); Seibel, Christoph; Hauschild, Dirk; Reinert, Friedrich [Karlsruhe Institute of Technology - KIT, Gemeinschaftslabor für Nanoanalytik, Karlsruhe (Germany); Abdollahian, Hossein [Nanotechnology Research Center of Urmia University, Urmia, (Iran, Islamic Republic of)

    2016-11-15

    TiO{sub 2} nanoparticles have been synthesized by the sol-gel method using titanium alkoxide and isopropanol as a precursor. The structural properties and chemical composition of the TiO{sub 2} nanoparticles were studied using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy.The X-ray powder diffraction pattern confirms that the particles are mainly composed of the anatase phase with the preferential orientation along [101] direction. The physical parameters such as strain, stress and energy density were investigated from the Williamson- Hall (W-H) plot assuming a uniform deformation model (UDM), and uniform deformation energy density model (UDEDM). The W-H analysis shows an anisotropic nature of the strain in nano powders. The scanning electron microscopy image shows clear TiO{sub 2} nanoparticles with particle sizes varying from 60 to 80nm. The results of mean particle size of TiO{sub 2} nanoparticles show an inter correlation with the W-H analysis and SEM results. Our X-ray photoelectron spectroscopy spectra show that nearly a complete amount of titanium has reacted to TiO{sub 2}. (author)

  15. Titanium dioxide nanoparticle ingestion alters nutrient absorption in an in vitro model of the small intestine

    Science.gov (United States)

    Ingestion of nanoparticles from products such as agricultural chemicals, processed food, and nutritional supplements is nearly unavoidable. The gastrointestinal tract serves as a critical interface and a barrier between the body and the external environment, and is the site of essential nutrient abs...

  16. Transport of Nanoparticles of Zerovalent Copper, Zinc Oxide, and Titanium Dioxide in Saturated Porous Media

    Science.gov (United States)

    Column tests show nanoparticles (NPs) of Cu(0) and ZnO were immobile at neutral pH in saturated sand.They became mobile in the presence of trizma, humic/fulvic, and citric/oxalic/formic acids. Copper NPs were mobile at pH 9. The deposition rates of TiO2 NP aggregates in both KCl ...

  17. Toxicity assessment of Titanium Dioxide and Cerium Oxide nanoparticles in Arabidopsis thaliana L.

    Science.gov (United States)

    The production and applications of nanoparticles (NP) in diverse fields has steadily increased in recent decades; however, knowledge about risks of NP to human health and ecosystems is still scarce. In this study, we assessed potential toxicity of two commercially used engineere...

  18. Effects of titanium dioxide nanoparticles derived from consumer products on the marine diatom Thalassiosira pseudonana

    Science.gov (United States)

    Increased manufacture of TiO2 nano-products has caused concern about the potential toxicity of these products to the environment and in public health. Identification and confirmation of the presence of TiO2 nanoparticles derived from consumer products as opposed to industrial TiO...

  19. Surface Changes and Impurity Release Kinetics of Titanium Dioxide Nanoparticles in Aqueous Environment

    Science.gov (United States)

    Previous studies have found the significant role of impurities (i.e., silicon, phosphorus) in the aggregation and sedimentation of TiO2 nanoparticles in water environment. However, it is not understood whether dissolution of the impurities potentially impacts the environment or t...

  20. Cellular Response to Titanium Dioxide Nanoparticles in Intestinal Epithelial Caco-2 Cells is Dependent on Endocytosis-Associated Structures and Mediated by EGFR

    Science.gov (United States)

    Krüger, Kristin; Schrader, Katrin; Klempt, Martin

    2017-01-01

    Titanium dioxide (TiO2) is one of the most applied nanomaterials and widely used in food and non-food industries as an additive or coating material (E171). It has been shown that E171 contains up to 37% particles which are smaller than 100 nm and that TiO2 nanoparticles (NPs) induce cytotoxicity and inflammation. Using a nuclear factor Kappa-light-chain enhancer of activated B cells (NF-κB) reporter cell line (Caco-2nfkb-RE), Real time polymerase chain reaction (PCR), and inhibition of dynamin and clathrin, it was shown that cellular responses induced by 5 nm and 10 nm TiO2 NPs (nominal size) depends on endocytic processes. As endocytosis is often dependent on the epithelial growth factor receptor (EGFR), further investigations focused on the involvement of EGFR in the uptake of TiO2 NPs: (1) inhibition of EGFR reduced inflammatory markers of the cell (i.e., nuclear factor (NF)-κB activity, mRNA of IL8, CCL20, and CXCL10); and (2) exposure of Caco-2 cells to TiO2 NPs activated the intracellular EGFR cascade beginning with EGFR-mediated extracellular signal-regulated kinases (ERK)1/2, and including transcription factor ELK1. This was followed by the expression of ERK1/2 target genes CCL2 and CXCL3. We concluded that TiO2 NPs enter the cell via EGFR-associated endocytosis, followed by activation of the EGFR/ERK/ELK signaling pathway, which finally induces NF-κB. No changes in inflammatory response are observed in Caco-2 cells exposed to 32 nm and 490 nm TiO2 particles. PMID:28387727

  1. Cellular Response to Titanium Dioxide Nanoparticles in Intestinal Epithelial Caco-2 Cells is Dependent on Endocytosis-Associated Structures and Mediated by EGFR.

    Science.gov (United States)

    Krüger, Kristin; Schrader, Katrin; Klempt, Martin

    2017-04-07

    Titanium dioxide (TiO₂) is one of the most applied nanomaterials and widely used in food and non-food industries as an additive or coating material (E171). It has been shown that E171 contains up to 37% particles which are smaller than 100 nm and that TiO₂ nanoparticles (NPs) induce cytotoxicity and inflammation. Using a nuclear factor Kappa-light-chain enhancer of activated B cells (NF-κB) reporter cell line (Caco-2 nfkb-RE ), Real time polymerase chain reaction (PCR), and inhibition of dynamin and clathrin, it was shown that cellular responses induced by 5 nm and 10 nm TiO₂ NPs (nominal size) depends on endocytic processes. As endocytosis is often dependent on the epithelial growth factor receptor (EGFR), further investigations focused on the involvement of EGFR in the uptake of TiO₂ NPs: (1) inhibition of EGFR reduced inflammatory markers of the cell (i.e., nuclear factor (NF)-κB activity, mRNA of IL8, CCL20, and CXCL10); and (2) exposure of Caco-2 cells to TiO₂ NPs activated the intracellular EGFR cascade beginning with EGFR-mediated extracellular signal-regulated kinases (ERK)1/2, and including transcription factor ELK1. This was followed by the expression of ERK1/2 target genes CCL2 and CXCL3. We concluded that TiO₂ NPs enter the cell via EGFR-associated endocytosis, followed by activation of the EGFR/ERK/ELK signaling pathway, which finally induces NF-κB. No changes in inflammatory response are observed in Caco-2 cells exposed to 32 nm and 490 nm TiO₂ particles.

  2. Microsomal Glutathione Transferase 1 Protects Against Toxicity Induced by Silica Nanoparticles but Not by Zinc Oxide Nanoparticles

    Science.gov (United States)

    2012-01-01

    Microsomal glutathione transferase 1 (MGST1) is an antioxidant enzyme located predominantly in the mitochondrial outer membrane and endoplasmic reticulum and has been shown to protect cells from lipid peroxidation induced by a variety of cytostatic drugs and pro-oxidant stimuli. We hypothesized that MGST1 may also protect against nanomaterial-induced cytotoxicity through a specific effect on lipid peroxidation. We evaluated the induction of cytotoxicity and oxidative stress by TiO2, CeO2, SiO2, and ZnO in the human MCF-7 cell line with or without overexpression of MGST1. SiO2 and ZnO nanoparticles caused dose- and time-dependent toxicity, whereas no obvious cytotoxic effects were induced by nanoparticles of TiO2 and CeO2. We also noted pronounced cytotoxicity for three out of four additional SiO2 nanoparticles tested. Overexpression of MGST1 reversed the cytotoxicity of the main SiO2 nanoparticles tested and for one of the supplementary SiO2 nanoparticles but did not protect cells against ZnO-induced cytotoxic effects. The data point toward a role of lipid peroxidation in SiO2 nanoparticle-induced cell death. For ZnO nanoparticles, rapid dissolution was observed, and the subsequent interaction of Zn2+ with cellular targets is likely to contribute to the cytotoxic effects. A direct inhibition of MGST1 by Zn2+ could provide a possible explanation for the lack of protection against ZnO nanoparticles in this model. Our data also showed that SiO2 nanoparticle-induced cytotoxicity is mitigated in the presence of serum, potentially through masking of reactive surface groups by serum proteins, whereas ZnO nanoparticles were cytotoxic both in the presence and in the absence of serum. PMID:22303956

  3. Titanium dioxide nanoparticles modified by salicylic acid and arginine: Structure, surface properties and photocatalytic decomposition of p-nitrophenol

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lei [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, North University of China, Taiyuan 030051 (China); Feng, Yujie, E-mail: yujief@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Liu, Youzhi; Wei, Bing; Guo, Jiaxin; Jiao, Weizhou [Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, North University of China, Taiyuan 030051 (China); Zhang, Zhaohan [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Zhang, Qiaoling, E-mail: zhangqiaoling@nuc.edu.cn [Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, North University of China, Taiyuan 030051 (China)

    2016-02-15

    Graphical abstract: A simple and versatile synthetic method to produce TiO{sub 2} nanoparticles surface-modified with various organic capping agents can be used for novel multifunctional photocatalysts as required for various applications in energy saving and environmental protection. - Highlights: • SA and Arg was modified through the method of dipping treatment-based on chemical adsorption in saturated solution. • Surface modified TiO{sub 2} applied in photodecomposition of nitroaromatic. • The photoreduction of nitroaromatic and photocatalytic activity under visible light irradiation were enhanced by TiO{sub 2}–SA–Arg. • TiO{sub 2}–SA–Arg showed better lipophilic, dispersion and adsorption properties. - Abstract: In this study, titanium dioxide (TiO{sub 2}) nanoparticles were surface-modified with salicylic acid (SA) and arginine (Arg) using an environmentally friendly and convenient method, and the bonding structure, surface properties and degradation efficiency of p-nitrophenol (PNP) were investigated. X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), water contact angle (WCA) measurements, ζ-potentiometric analysis, UV/visible diffuse reflectance spectroscopy (UV–vis DRS), and thermogravimetric analysis (TGA) were performed to evaluate the modification effect. The degradation rates were determined by high-performance liquid chromatography (HPLC). The results show that bidentate or bridging bonds are most likely formed between SA/Arg and TiO{sub 2} surface. Surface modification with SA, Arg, or both can improve the lipophilic properties and decrease the zeta potential, and also result in a red shift of the absorption wavelength. TiO{sub 2} nanoparticles modified by Arg or both SA and Arg show a large specific surface area and pore volume. Further, degradation

  4. Effects of zinc oxide and titanium dioxide nanoparticles on green algae under visible, UVA, and UVB irradiations: no evidence of enhanced algal toxicity under UV pre-irradiation.

    Science.gov (United States)

    Lee, Woo-Mi; An, Youn-Joo

    2013-04-01

    Some metal oxide nanoparticles are photoreactive, thus raising concerns regarding phototoxicity. This study evaluated ecotoxic effects of zinc oxide nanoparticles and titanium dioxide nanoparticles to the green algae Pseudokirchneriella subcapitata under visible, UVA, and UVB irradiation conditions. The nanoparticles were prepared in algal test medium, and the test units were pre-irradiated by UV light in a photoreactor. Algal assays were also conducted with visible, UVA or UVB lights only without nanoparticles. Algal growth was found to be inhibited as the nanoparticle concentration increased, and ZnO NPs caused destabilization of the cell membranes. We also noted that the inhibitory effects on the growth of algae were not enhanced under UV pre-irradiation conditions. This phenomenon was attributed to the photocatalytic activities of ZnO NPs and TiO2 NPs in both the visible and UV regions. The toxicity of ZnO NPs was almost entirely the consequence of the dissolved free zinc ions. This study provides us with an improved understanding of toxicity of photoreactive nanoparticles as related to the effects of visible and UV lights. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Surface modification of polyamide thin film composite membrane by coating of titanium dioxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Thu Hong Anh Ngo

    2016-12-01

    Full Text Available In this paper, the coating of TiO2 nanoparticles onto the surface of a polyamide thin film composite nanofiltration membrane has been studied. Changes in the properties and separation performance of the modified membranes were systematically characterized. The experimental results indicated that the membrane surface hydrophilicity was significantly improved by the presence of the coated TiO2 nanoparticles with subsequent UV irradiation. The separation performance of the UV-irradiated TiO2-coated membranes was improved with a great enhancement of flux and a very high retention for removal of residual dye in an aqueous feed solution. The antifouling property of the UV-irradiated TiO2-coated membranes was enhanced with higher maintained flux ratios and lower irreversible fouling factors compared with an uncoated membrane.

  6. Noble metals nanoparticles on titanium dioxide nanostructured films and the influence of their photocatalytic activity

    International Nuclear Information System (INIS)

    Nakamura, Liana Key Okada

    2012-01-01

    Currently, nanoscience and nanotechnology are considered an emerging field and continuously breaking the barrier among various disciplines. The main focus of study involves controlling structures at molecular level, arranging the atoms in order to achieve an understanding and controlling the fundamental properties of matter. In this study, molecular changes on the basis of morphology, optical and crystalline properties of TiO 2 hin films in order to increase their photon efficiency were proposed. The TiO 2 thin films were prepared by sol gel process evaluating the influence of different acids and templates to obtain the nano structured arrangements. Then, metal nanoparticles like Au, Ag, Pd and Pt were incorporated on TiO 2 thin films. This incorporation might minimize the electron-hole recombination, so it could improve the photon efficiency. From the several routes studied, the TiO 2 thin films prepared with acetic acid showed the best performance by the reason of low agglomeration of TiO 2 grains, which favors the exposure of the photoactive sites. The presence of template in the formulation had a slightly effect on photon efficiency, possible due to the higher agglomeration of the grains on the TiO 2 thin films. The addition of Pt and Au nanoparticles on TiO 2 thin films showed superior photon efficiency. The TiO 2 thin films with hexamine and metallic nanoparticles did not show the improvement on photon efficiency except for Pt and Au nanoparticles. On these situations, the improvement on photon efficiency is might be due to a possible decrease at the electron-hole recombination's velocity. Thus, the present work demonstrates the great influence of preparation conditions on the optical, morphological properties and the photon efficiency. In the future, with greater understanding of the mechanism of this influence, the properties of TiO 2 thin films will be able tailoring depending on the application. (author)

  7. Morphology controlled graphene-alloy nanoparticle hybrids with tunable carbon monoxide conversion to carbon dioxide.

    Science.gov (United States)

    Devi, M Manolata; Dolai, N; Sreehala, S; Jaques, Y M; Mishra, R S Kumar; Galvao, Douglas S; Tiwary, C S; Sharma, Sudhanshu; Biswas, Krishanu

    2018-05-10

    Selective oxidation of CO to CO2 using metallic or alloy nanoparticles as catalysts can solve two major problems of energy requirements and environmental pollution. Achieving 100% conversion efficiency at a lower temperature is a very important goal. This requires sustained efforts to design and develop novel supported catalysts containing alloy nanoparticles. In this regard, the decoration of nanoalloys with graphene, as a support for the catalyst, can provide a novel structure due to the synergic effect of the nanoalloys and graphene. Here, we demonstrate the effect of nano-PdPt (Palladium-Platinum) alloys having different morphologies on the catalytic efficiency for the selective oxidation of CO. Efforts were made to prepare different morphologies of PdPt alloy nanoparticles with the advantage of tuning the capping agent (PVP - polyvinyl pyrollidone) and decorating them on graphene sheets via the wet-chemical route. The catalytic activity of the G-PdPt hybrids with an urchin-like morphology has been found to be superior (higher % conversion at 135 °C lower) to that with a nanoflower morphology. The above experimental observations are further supported by molecular dynamics (MD) simulations.

  8. Patterned immobilisation of silicon dioxide nanoparticles on the surface of a photosensitive polymer

    Energy Technology Data Exchange (ETDEWEB)

    Muhr, Nina, E-mail: nina.muhr@unileoben.ac.at [Chair of Chemistry of Polymeric Materials, University of Leoben, Otto-Gloeckel-Strasse 2, A-8700 Leoben (Austria); Grinschgl, Markus; Griesser, Thomas [Chair of Chemistry of Polymeric Materials, University of Leoben, Otto-Gloeckel-Strasse 2, A-8700 Leoben (Austria); Kern, Wolfgang [Chair of Chemistry of Polymeric Materials, University of Leoben, Otto-Gloeckel-Strasse 2, A-8700 Leoben (Austria); Polymer Competence Center Leoben GmbH, Peter-Rosegger-Strasse 12, A-8700 Leoben (Austria); Schroettner, Hartmuth [Institute for Electron Microscopy, Technical University of Graz, Steyrergasse 17, A-8010 Graz (Austria)

    2012-01-01

    A photosensitive co-polymer of styrene and 4-vinylbenzyl thiocyanate was synthesised and employed for the immobilisation of aminofunctionalised silica nanoparticles (SiO{sub 2}-NP) at the polymer surface. Upon UV irradiation of the co-polymer, isothiocyanate groups are generated by a photo-isomerisation reaction of the thiocyanate groups. The silica nanoparticles were selectively immobilised in irradiated areas by immersing the illuminated polymer surface in a solution of SiO{sub 2}-NP. Depending on the time of immersion and the nanoparticle concentration, different amounts of silica can be deposited in the irradiated areas, whilst no immobilisation of SiO{sub 2}-NP is observed in the non-irradiated areas. By using photolithographic methods, patterned silica structures ({mu}m scale) were produced on the polymer surface. The SiO{sub 2}-NP covered surfaces are of potential interest to generate protective surface layers and to carry out further functionalisation reactions of the immobilised SiO{sub 2}-NP particles.

  9. Re-evaluation of pulmonary titanium dioxide nanoparticle distribution using the "relative deposition index": Evidence for clearance through microvasculature

    Directory of Open Access Journals (Sweden)

    Gehr Peter

    2007-08-01

    Full Text Available Abstract Background Translocation of nanoparticles (NP from the pulmonary airways into other pulmonary compartments or the systemic circulation is controversially discussed in the literature. In a previous study it was shown that titanium dioxide (TiO2 NP were "distributed in four lung compartments (air-filled spaces, epithelium/endothelium, connective tissue, capillary lumen in correlation with compartment size". It was concluded that particles can move freely between these tissue compartments. To analyze whether the distribution of TiO2 NP in the lungs is really random or shows a preferential targeting we applied a newly developed method for comparing NP distributions. Methods Rat lungs exposed to an aerosol containing TiO2 NP were prepared for light and electron microscopy at 1 h and at 24 h after exposure. Numbers of TiO2 NP associated with each compartment were counted using energy filtering transmission electron microscopy. Compartment size was estimated by unbiased stereology from systematically sampled light micrographs. Numbers of particles were related to compartment size using a relative deposition index and chi-squared analysis. Results Nanoparticle distribution within the four compartments was not random at 1 h or at 24 h after exposure. At 1 h the connective tissue was the preferential target of the particles. At 24 h the NP were preferentially located in the capillary lumen. Conclusion We conclude that TiO2 NP do not move freely between pulmonary tissue compartments, although they can pass from one compartment to another with relative ease. The residence time of NP in each tissue compartment of the respiratory system depends on the compartment and the time after exposure. It is suggested that a small fraction of TiO2 NP are rapidly transported from the airway lumen to the connective tissue and subsequently released into the systemic circulation.

  10. Effect of titanium dioxide nanoparticles (TiO2 NPs) on the expression of mucin genes in human airway epithelial cells.

    Science.gov (United States)

    Kim, Gui Ok; Choi, Yoon Seok; Bae, Chang Hoon; Song, Si-Youn; Kim, Yong-Dae

    2017-01-01

    Titanium dioxide nanoparticles (TiO 2 NPs) are utilized with growing frequency for a wide variety of industrial applications. Recently, acute and chronic exposures to TiO 2 NPs have been found to induce inflammatory response in the human respiratory tract. However, the effect and mechanism underlying the induction of major airway mucins by TiO 2 NPs have not been elucidated. This study was conducted to characterize the effect of TiO 2 NPs, and the mechanism involved, on the expressions of airway mucins in human airway epithelial cells. In NCI-H292 cells and primary cultures of normal nasal epithelial cells, the effects of TiO 2 NPs and signaling pathway for airway mucin genes were investigated by reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR, enzyme immunoassays and immunoblot analysis using several specific inhibitors and small interfering RNAs (siRNAs). TiO 2 NPs increased MUC5B expression and activated the phosphorylations of extracellular signal-related kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK). U0126 (an ERK1/2 MAPK inhibitor) and SB203580 (a p38 MAPK inhibitor) inhibited TiO 2 NPs-induced MUC5B expression. And knockdown of ERK1, ERK2 and p38 MAPK using siRNAs significantly blocked TiO 2 NPs-induced MUC5B mRNA expression. Furthermore, Toll-like receptor 4 (TLR4) mRNA expression was increased by TiO 2 NPs, and knockdown by TLR4 siRNA significantly attenuated TiO 2 NPs-induced MUC5B mRNA expression and the TiO 2 NPs-induced phosphorylations of ERK1/2 and p38 MAPK. These results demonstrate for the first time that TiO 2 NPs induce MUC5B expression via TLR4-dependent ERK1/2 and p38 MAPK signaling pathways in respiratory epithelium.

  11. Photocatalytic activity of titanium dioxide modified by Fe2O3 nanoparticles

    International Nuclear Information System (INIS)

    Wodka, Dawid; Socha, Robert P.; Bielańska, Elżbieta; Elżbieciak-Wodka, Magdalena; Nowak, Paweł; Warszyński, Piotr

    2014-01-01

    Highlights: • 1% Fe 2 O 3 /TiO 2 composite showing high activity in the photocatalytic oxidation of organics was synthetized. • Electrochemical analysis indicated that surface modification of Degussa P25 by Fe 2 O 3 causes the appearance of surface states in such a material. • The enhanced activity of the prepared composite may be ascribed to the occurrence of the photo-Fenton process. - Abstract: Photocatalytic activity of Fe 2 O 3 /TiO 2 composites obtained by precipitation was investigated. The composite material containing 1.0 wt% of iron(III) oxide nanoparticles was obtained by depositing Fe 2 O 3 on the Evonic-Degussa P25 titania surface. SEM, XPS, DRS, CV and EIS techniques were applied to examine synthetized pale orange photocatalyst. The XPS measurements revealed that iron is present mainly in the +3 oxidation state but iron in the +2 oxidation state can be also detected. Electrochemical analysis indicated that surface modification of Degussa P25 by Fe 2 O 3 causes the appearance of surface states in such a material. Nevertheless, based on the DRS measurement it was shown that iron(III) oxide nanoparticles modified the P25 spectral properties but they did not change the band gap width. The photocatalytic activity of Fe 2 O 3 /TiO 2 composite was compared to photocatalytic activity of pristine P25 in photooxidation reaction of model compounds: oxalic acid (OxA) and formic acid (FA). Photodecomposition reaction was investigated in a batch reactor containing aqueous suspension of a photocatalyst illuminated by either UV or artificial sunlight (halogen lamp). The tests proved that nanoparticles deposited on titania surface triggers the increase in photocatalytic activity, this increase depends however on the decomposed substance

  12. Interaction of fibrinogen and albumin with titanium dioxide nanoparticles of different crystalline phases

    International Nuclear Information System (INIS)

    Marucco, Arianna; Fenoglio, Ivana; Turci, Francesco; Fubini, Bice

    2013-01-01

    TiO 2 nanoparticles (NPs) are contained in different kinds of industrial products including paints, self-cleaning glasses, sunscreens. TiO 2 is also employed in photocatalysis and it has been proposed for waste water treatment. Micrometric TiO 2 is generally considered a safe material, while there is concern on the possible health effects of nanometric titania. Due to their small size NPs may migrate within the human body possibly entering in the blood stream. Therefore studies on the interaction of NPs with plasma proteins are needed. In fact, the interaction with proteins is believed to ultimately influences the NPs biological fate. Fibrinogen and albumin are two of the most abundant plasma proteins. They are involved in several important physiological functions. Furthermore, fibrinogen is known to trigger platelet adhesion and inflammation. For these reasons the study of the interaction between these protein and nanoparticles is an important step toward the understanding of the behavior of NPs in the body. In this study we investigated the interaction of albumin and fibrinogen with TiO 2 nanoparticles of different crystal phases (rutile and anatase) using an integrated set of techniques. The amount of adsorbed fibrinogen and albumin for each TiO 2 surface was investigated by using the bicinchoninic acid assay (BCA). The variation of the surface charge of the NP-protein conjugates respect to the naked NPs was used to indirectly estimate both surface coverage and reversibility of the adsorption upon dilution. Surface charge was monitored by measuring the ζ potential with a conventional electrophoretic light scattering (ELS) system. The extent of protein deformation was evaluated by Raman Spectroscopy. We found that both proteins adsorb irreversibly against electrostatic repulsion, likely undergoing conformational changes or selective orientation upon adsorption. The size of primary particles and the particles aggregation rather than the crystal phase modulate the

  13. Photocatalytic activity of titanium dioxide modified by Fe{sub 2}O{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wodka, Dawid [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland); Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4 (Switzerland); Socha, Robert P.; Bielańska, Elżbieta [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland); Elżbieciak-Wodka, Magdalena [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland); Department of Analytical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4 (Switzerland); Nowak, Paweł, E-mail: ncnowak@cyf-kr.edu.pl [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland); Warszyński, Piotr [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland)

    2014-11-15

    Highlights: • 1% Fe{sub 2}O{sub 3}/TiO{sub 2} composite showing high activity in the photocatalytic oxidation of organics was synthetized. • Electrochemical analysis indicated that surface modification of Degussa P25 by Fe{sub 2}O{sub 3} causes the appearance of surface states in such a material. • The enhanced activity of the prepared composite may be ascribed to the occurrence of the photo-Fenton process. - Abstract: Photocatalytic activity of Fe{sub 2}O{sub 3}/TiO{sub 2} composites obtained by precipitation was investigated. The composite material containing 1.0 wt% of iron(III) oxide nanoparticles was obtained by depositing Fe{sub 2}O{sub 3} on the Evonic-Degussa P25 titania surface. SEM, XPS, DRS, CV and EIS techniques were applied to examine synthetized pale orange photocatalyst. The XPS measurements revealed that iron is present mainly in the +3 oxidation state but iron in the +2 oxidation state can be also detected. Electrochemical analysis indicated that surface modification of Degussa P25 by Fe{sub 2}O{sub 3} causes the appearance of surface states in such a material. Nevertheless, based on the DRS measurement it was shown that iron(III) oxide nanoparticles modified the P25 spectral properties but they did not change the band gap width. The photocatalytic activity of Fe{sub 2}O{sub 3}/TiO{sub 2} composite was compared to photocatalytic activity of pristine P25 in photooxidation reaction of model compounds: oxalic acid (OxA) and formic acid (FA). Photodecomposition reaction was investigated in a batch reactor containing aqueous suspension of a photocatalyst illuminated by either UV or artificial sunlight (halogen lamp). The tests proved that nanoparticles deposited on titania surface triggers the increase in photocatalytic activity, this increase depends however on the decomposed substance.

  14. A Carbon Dioxide Bubble-Induced Vortex Triggers Co-Assembly of Nanotubes with Controlled Chirality.

    Science.gov (United States)

    Zhang, Ling; Zhou, Laicheng; Xu, Na; Ouyang, Zhenjie

    2017-07-03

    It is challenging to prepare co-organized nanotube systems with controlled nanoscale chirality in an aqueous liquid flow field. Such systems are responsive to a bubbled external gas. A liquid vortex induced by bubbling carbon dioxide (CO 2 ) gas was used to stimulate the formation of nanotubes with controlled chirality; two kinds of achiral cationic building blocks were co-assembled in aqueous solution. CO 2 -triggered nanotube formation occurs by formation of metastable intermediate structures (short helical ribbons and short tubules) and by transition from short tubules to long tubules in response to chirality matching self-assembly. Interestingly, the chirality sign of these assemblies can be selected for by the circulation direction of the CO 2 bubble-induced vortex during the co-assembly process. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Evaluating the use of zinc oxide and titanium dioxide nanoparticles in a metalworking fluid from a toxicological perspective

    Energy Technology Data Exchange (ETDEWEB)

    Seyedmahmoudi, S. H. [Oregon State University, Industrial Sustainability Laboratory, School of Mechanical, Industrial, and Manufacturing Engineering (United States); Harper, Stacey L. [Oregon State University, Department of Environmental and Molecular Toxicology & School of Chemical, Biological and Environmental Engineering (United States); Weismiller, Michael C. [Master Chemical Corporation (United States); Haapala, Karl R., E-mail: karl.haapala@oregonstate.edu [Oregon State University, Industrial Sustainability Laboratory, School of Mechanical, Industrial, and Manufacturing Engineering (United States)

    2015-02-15

    Adding nanoparticles (NPs) to metalworking fluids (MWFs) has been shown to improve performance in metal cutting. Zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO{sub 2} NPs), for example, have exhibited the ability to improve lubricant performance, decrease the heat created by machining operations, reduce friction and wear, and enhance thermal conductivity. ZnO and TiO{sub 2} NPs are also relatively inexpensive compared to many other NPs. Precautionary concerns of human health risks and environmental impacts, however, are especially important when adding NPs to MWFs. The goal of this research is to investigate the potential environmental and human health effects of these nanoenabled products during early design and development. This research builds on a prior investigation of the stability and toxicity characteristics of NPs used in metalworking nanofluids (MWnF™). The previous study only investigated one type of NP at one level of concentration. This research expands on the previous investigations through the valuation of three different types of NPs that vary in morphology (size and shape) and was conducted over a wide range of concentrations in the base fluid. In the presented work, mixtures of a microemulsion (TRIM{sup ®} MicroSol{sup ®} 585XT), two different types of TiO{sub 2} NPs (referred to as TiO{sub 2}A and TiO{sub 2}B) and one type of ZnO NP were used to evaluate MWnF™ stability and toxicity. Dynamic light scattering was used to assess stability over time and an embryonic zebrafish assay was used to assess toxicological impacts. The results reveal that, in general, the addition of these NPs increased toxicity relative to the NP-free formulation. The lowest rate of zebrafish malformations occurred at 5 g/L TiO{sub 2}A NP, which was even lower than for the base fluid. This result is particularly promising for future MWnF™ development, given that the mortality rate for 5 g/L TiO{sub 2}A was not significantly different

  16. Titanium dioxide nanoparticles stimulate sea urchin immune cell phagocytic activity involving TLR/p38 MAPK-mediated signalling pathway

    Science.gov (United States)

    Pinsino, Annalisa; Russo, Roberta; Bonaventura, Rosa; Brunelli, Andrea; Marcomini, Antonio; Matranga, Valeria

    2015-01-01

    Titanium dioxide nanoparticles (TiO2NPs) are one of the most widespread-engineered particles in use for drug delivery, cosmetics, and electronics. However, TiO2NP safety is still an open issue, even for ethical reasons. In this work, we investigated the sea urchin Paracentrotus lividus immune cell model as a proxy to humans, to elucidate a potential pathway that can be involved in the persistent TiO2NP-immune cell interaction in vivo. Morphology, phagocytic ability, changes in activation/inactivation of a few mitogen-activated protein kinases (p38 MAPK, ERK), variations of other key proteins triggering immune response (Toll-like receptor 4-like, Heat shock protein 70, Interleukin-6) and modifications in the expression of related immune response genes were investigated. Our findings indicate that TiO2NPs influence the signal transduction downstream targets of p38 MAPK without eliciting an inflammatory response or other harmful effects on biological functions. We strongly recommend sea urchin immune cells as a new powerful model for nano-safety/nano-toxicity investigations without the ethical normative issue. PMID:26412401

  17. Role of toll-like receptors 3, 4 and 7 in cellular uptake and response to titanium dioxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Peng Chen, Koki Kanehira and Akiyoshi Taniguchi

    2013-01-01

    Full Text Available Innate immune response is believed to be among the earliest provisional cellular responses, and mediates the interactions between microbes and cells. Toll-like receptors (TLRs are critical to these interactions. We hypothesize that TLRs also play an important role in interactions between nanoparticles (NPs and cells, although little information has been reported concerning such an interaction. In this study, we investigated the role of TLR3, TLR4 and TLR7 in cellular uptake of titanium dioxide NP (TiO2 NP agglomerates and the resulting inflammatory responses to these NPs. Our data indicate that TLR4 is involved in the uptake of TiO2 NPs and promotes the associated inflammatory responses. The data also suggest that TLR3, which has a subcellular location distinct from that of TLR4, inhibits the denaturation of cellular protein caused by TiO2 NPs. In contrast, the unique cellular localization of TLR7 has middle-ground functional roles in cellular response after TiO2 NP exposure. These findings are important for understanding the molecular interaction mechanisms between NPs and cells.

  18. Influence of Titanium Dioxide Nanoparticles on the Sulfate Attack upon Ordinary Portland Cement and Slag-Blended Mortars

    Directory of Open Access Journals (Sweden)

    Atta-ur-Rehman

    2018-02-01

    Full Text Available In this study, the effects of titanium dioxide (TiO2 nanoparticles on the sulfate attack resistance of ordinary Portland cement (OPC and slag-blended mortars were investigated. OPC and slag-blended mortars (OPC:Slag = 50:50 were made with water to binder ratio of 0.4 and a binder to sand ratio of 1:3. TiO2 was added as an admixture as 0%, 3%, 6%, 9% and 12% of the binder weight. Mortar specimens were exposed to an accelerated sulfate attack environment. Expansion, changes in mass and surface microhardness were measured. Scanning Electron Microscopy (SEM, Energy Dispersive Spectroscopy (EDS, X-ray Diffraction (XRD, Thermogravimetry Analysis (TGA and Differential Scanning Calorimetry (DSC tests were conducted. The formation of ettringite and gypsum crystals after the sulfate attack were detected. Both these products had caused crystallization pressure in the microstructure of mortars and deteriorated the mortars. Our results show that the addition of nano-TiO2 accelerated expansion, variation in mass, loss of surface microhardness and widened cracks in OPC and slag-blended mortars. Nano-TiO2 containing slag-blended mortars were more resistant to sulfate attack than nano-TiO2 containing OPC mortars. Because nano-TiO2 reduced the size of coarse pores, so it increased crystallization pressure due to the formation of ettringite and gypsum thus led to more damage under sulfate attack.

  19. Plasticized Starch Based Bionanocomposites Containing Cellulose Nanowhiskers and Titanium Dioxide Nanoparticles: Study of Structure and Water Vapor Permeability

    Directory of Open Access Journals (Sweden)

    Nasrin Jamshidi Kaljahi

    2014-08-01

    Full Text Available The starch-based films have some disadvantages such as weak mechanical and poor water barrier properties that restrict their applications in food packaging. In the present research, to improve the properties of the starch films, a constant level of citric acid and polyvinyl alcohol (PVA (10% with different amounts of glycerol (GLY as a lubricating agent, crystal nanowhiskers (CNW and titanium dioxide (TiO2 nanoparticles were used together. Finally, the effects of these compounds on permeability properties of the obtained starch-based bionanocomposites were studied and their optimum values were determined by central composite design of response surface methodology (RSM. The results of X-Ray diffraction (XRD test showed that at low levels of TiO2 and CNW there was no diffractogram peak obtained. However, at high levels of TiO2 and CNW there emerged distinct and sharp peak which was attributed to greater crystalline region and probably non-homogeneity in particle distribution. The Fourier transmission infrared (FTIR data showed that addition of CNW and TiO2 increased hydrogen binding between the nanofillers and biopolymer matrix. The effects of TiO2 and CNW concentrations as quadratic and glycerol concentration as linear and quadratic were significant on water vapor permeability (WVP. The optimum levels of TiO2, CNW and GLY for obtaining minimum WVP corresponded to 0.118, 0.3 g and 1.06 mL, respectively.

  20. Retention of titanium dioxide nanoparticles in biological activated carbon filters for drinking water and the impact on ammonia reduction.

    Science.gov (United States)

    Liu, Zhiyuan; Yu, Shuili; Park, Heedeung; Liu, Guicai; Yuan, Qingbin

    2016-06-01

    Given the increasing discoveries related to the eco-toxicity of titanium dioxide (TiO2) nanoparticles (NPs) in different ecosystems and with respect to public health, it is important to understand their potential effects in drinking water treatment (DWT). The effects of TiO2 NPs on ammonia reduction, ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in biological activated carbon (BAC) filters for drinking water were investigated in static and dynamic states. In the static state, both the nitrification potential and AOB were significantly inhibited by 100 μg L(-1) TiO2 NPs after 12 h (p  0.05). In the dynamic state, different amounts of TiO2 NP pulses were injected into three pilot-scale BAC filters. The decay of TiO2 NPs in the BAC filters was very slow. Both titanium quantification and scanning electron microscope analysis confirmed the retention of TiO2 NPs in the BAC filters after 134 days of operation. Furthermore, the TiO2 NP pulses considerably reduced the performance of ammonia reduction. This study identified the retention of TiO2 NPs in BAC filters and the negative effect on the ammonia reduction, suggesting a potential threat to DWT by TiO2 NPs.

  1. Efficiency of a Photoreactor Packed with Immobilized Titanium Dioxide Nanoparticles in the Removal of Acid Orange 7.

    Science.gov (United States)

    Sheidaei, Behnaz; Behnajady, Mohammad A

    2016-05-01

    In this paper, the removal efficiency of Color Index Acid Orange 7 (AO7) as a model contaminant was investigated in a batch-recirculated photoreactor packed with immobilized titanium dioxide type P25 nanoparticles on glass beads. The effects of different operational parameters such as the initial concentration of AO7, the volume of solution, the volumetric flowrate, and the light source power in the photoreactor were investigated. The results indicate that the removal percent increased with the rise in volumetric flowrate and power of the light source, but decreased with the rise of the initial concentration of AO7 and the volume of solution. The AO7 degradation was followed through total organic carbon, gas chromatography/mass spectroscopy (GC/MS), and mineralization products analysis. The ammonium and sulfate ions were analyzed as mineralization products of nitrogen and sulfur heteroatoms, respectively. The results of GC/MS revealed the production of 1-indanone, 1-phthalanone, and 2-naphthalenol as intermediate products for the removal of AO7 in this process.

  2. Luminescent Study of the Binding Interaction on 1,4-Dihydroxy-2,3-Dimethyl-9,10-Anthraquinone with Titanium Dioxide Nanoparticles

    Science.gov (United States)

    Pushpam, S.; Yamini, D.; Ramakrishnan, V.

    2014-07-01

    The photophysical properties of 1,4-dihydroxy-2,3-dimethyl-9,10-anthroquinone (DHDMAQ) in the absence and presence of titanium dioxide (TiO2) nanoparticles have been studied using UV-visible absorption spectroscopy and steady-state fluorescence spectroscopy. The fluorescence intensity of the DHDMAQ decreases as the concentration of TiO2 nanoparticles increases. The quenching is characterized by a Stern-Volmer plot, which displays a positive deviation from linearity. This could be explained by static quenching models. The Stern-Volmer quenching constant, association constant, and binding constant have been calculated. The distance between DHDMAQ and TiO2 nanoparticles has also been evaluated using Forster's theory of non-radiative energy transfer.

  3. An optimized nanoparticle separator enabled by electron beam induced deposition

    International Nuclear Information System (INIS)

    Fowlkes, J D; Rack, P D; Doktycz, M J

    2010-01-01

    Size-based separations technologies will inevitably benefit from advances in nanotechnology. Direct-write nanofabrication provides a useful mechanism for depositing/etching nanoscale elements in environments otherwise inaccessible to conventional nanofabrication techniques. Here, electron beam induced deposition was used to deposit an array of nanoscale features in a 3D environment with minimal material proximity effects outside the beam-interaction region. Specifically, the membrane component of a nanoparticle separator was fabricated by depositing a linear array of sharply tipped nanopillars, with a singular pitch, designed for sub-50 nm nanoparticle permeability. The nanopillar membrane was used in a dual capacity to control the flow of nanoparticles in the transaxial direction of the array while facilitating the sealing of the cellular-sized compartment in the paraxial direction. An optimized growth recipe resulted which (1) maximized the growth efficiency of the membrane (which minimizes proximity effects) and (2) preserved the fidelity of the spacing between nanopillars (which maximizes the size-based gating quality of the membrane) while (3) maintaining sharp nanopillar apexes for impaling an optically transparent polymeric lid critical for device sealing.

  4. An optimized nanoparticle separator enabled by electron beam induced deposition

    Science.gov (United States)

    Fowlkes, J. D.; Doktycz, M. J.; Rack, P. D.

    2010-04-01

    Size-based separations technologies will inevitably benefit from advances in nanotechnology. Direct-write nanofabrication provides a useful mechanism for depositing/etching nanoscale elements in environments otherwise inaccessible to conventional nanofabrication techniques. Here, electron beam induced deposition was used to deposit an array of nanoscale features in a 3D environment with minimal material proximity effects outside the beam-interaction region. Specifically, the membrane component of a nanoparticle separator was fabricated by depositing a linear array of sharply tipped nanopillars, with a singular pitch, designed for sub-50 nm nanoparticle permeability. The nanopillar membrane was used in a dual capacity to control the flow of nanoparticles in the transaxial direction of the array while facilitating the sealing of the cellular-sized compartment in the paraxial direction. An optimized growth recipe resulted which (1) maximized the growth efficiency of the membrane (which minimizes proximity effects) and (2) preserved the fidelity of the spacing between nanopillars (which maximizes the size-based gating quality of the membrane) while (3) maintaining sharp nanopillar apexes for impaling an optically transparent polymeric lid critical for device sealing.

  5. Investigating the growth mechanism and optical properties of carbon-coated titanium dioxide nanoparticles

    KAUST Repository

    Anjum, Dalaver H.

    2013-10-01

    TiO2 nanoparticles (NPs) were prepared using flame synthesis and then characterized using transmission electron microscopy. We found that the flame method yields both crystalline TiO2 and amorphous TiO 2 NPs. TEM analysis revealed that only the crystalline TiO 2 NPs were coated with carbon. Based on this observation, we proposed a growth model for the diffusion and precipitation of carbon atoms in TiO 2 NPs. The optical properties of TiO2 NPs were investigated by performing valence electron energy loss spectrometry analysis. We observed that carbon-coated TiO2 NPs have higher absorption in the visible range due to their lower band-gap energy. © 2013 Elsevier B.V.

  6. Nanorods and nanoparticles of titanium dioxide and their use in dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Govindaraj, R., E-mail: isrogovindaraj@gmail.com; Magesh, M.; Senthil Pandian, M.; Ramasamy, P. [Department of Physics, Research Centre, SSN College of Engineering, Kalavakkam, Chennai, Tamilnadu-603 110 (India); Mukhopadhyay, Sumita [Centre of Excellence for Green Energy and sensor systems, IIEST, Howrah, West Bengal-711 103 (India)

    2016-05-23

    Mesoporous TiO{sub 2} nanorods/nanorods were successfully synthesized by hydrothermal process at 170 °C for 72 hr. The powder X-ray diffraction pattern shows large fraction of anatase phase with good crystalline behavior of the prepared materials. The specific surface area and pore volume of the synthesized material are about 84.83 m{sup 2}/g and 0.1316 cc/g respectively. The morphological results show that the TiO{sub 2} nanorods had diameter of ~ 25 nm and the length of ~ 80 nm. The nanoparticles have 20 nm in size. The current-voltage curve shows that the synthesized TiO{sub 2} nanostructure results in 36.7 % higher solar cell efficiency than commercial P25.

  7. Food web effects of titanium dioxide nanoparticles in an outdoor freshwater mesocosm experiment.

    Science.gov (United States)

    Jovanović, Boris; Bezirci, Gizem; Çağan, Ali Serhan; Coppens, Jan; Levi, Eti E; Oluz, Zehra; Tuncel, Eylül; Duran, Hatice; Beklioğlu, Meryem

    2016-09-01

    Over the course of 78 days, nine outdoor mesocosms, each with 1350 L capacity, were situated on a pontoon platform in the middle of a lake and exposed to 0 μg L(-1) TiO2, 25 μg L(-1) TiO2 or 250 μg L(-1) TiO2 nanoparticles in the form of E171 TiO2 human food additive five times a week. Mesocosms were inoculated with sediment, phytoplankton, zooplankton, macroinvertebrates, macrophytes and fish before exposure, ensuring a complete food web. Physicochemical parameters of the water, nutrient concentrations, and biomass of the taxa were monitored. Concentrations of 25 μg L(-1) TiO2 and 250 μg L(-1) TiO2 caused a reduction in available soluble reactive phosphorus in the mesocosms by 15 and 23%, respectively, but not in the amount of total phosphorus. The biomass of Rotifera was significantly reduced by 32 and 57% in the TiO2 25 μg L(-1) and TiO2 250 μg L(-1) treatments, respectively, when compared to the control; however, the biomass of the other monitored groups-Cladocera, Copepoda, phytoplankton, macrophytes, chironomids and fish-remained unaffected. In conclusion, environmentally relevant concentrations of TiO2 nanoparticles may negatively affect certain parameters and taxa of the freshwater lentic aquatic ecosystem. However, these negative effects are not significant enough to affect the overall function of the ecosystem, as there were no cascade effects leading to a major change in its trophic state or primary production.

  8. Efficacy of titanium dioxide nanoparticle spray to disinfect mobile phones used by endodontist: A bacteriological study.

    Science.gov (United States)

    Palaniswamy, Udayakumar; Habeeb, Aisha; Mohsin, Mohammed

    2018-01-01

    The objectives of this study were to determine the bacterial contamination of the mobile phones that were used by the endodontist in comparison with the general dentist and also to determine the usefulness of titanium dioxide nanospray (TiO 2 NS) in mobile phone decontamination. Samples from the 60 mobile phones were taken using moist sterile swabs before, 10 min, and 1 week after the use of TiO 2 NS. Before collection of the swabs, the participants' informed consent was obtained. Samples obtained were cultured on blood agar to identify bacterial isolates. All 60 mobile phone cultures were found to be culture positive. There was a significant reduction in the mean number of colony-forming units after decontamination with TiO 2 NS ( P mobile phones may act as an important source of nosocomial pathogens and TiO 2 NS would be an effective decontaminant. Therefore, it is important for dental professionals to practice routine mobile phone disinfection protocol to reduce the chances of occurrence of nosocomial infections.

  9. Role of Carnosine and Melatonin in Ameliorating Cardiotoxicity of Titanium Dioxide Nanoparticles in the Rats

    Directory of Open Access Journals (Sweden)

    Nouf Al-Rasheed

    2015-08-01

    Full Text Available The aim of this work was to study the possible cardiotoxicity of two different doses of 50 nm nano titanium dioxide (n-TiO2 and the possible modulating effects of the use of two natural antioxidants carnosine and melatonin. The results showed that TiO2- NPs produced deleterious effects on rat cardiac tissue as confirmed by the increased levels of serum myoglobin, troponin-T and CK-MB. Increased levels of serum Inflammatory markers represented by the tumor necrosis factor alpha (TNF-α and Interleukin-6 (IL-6 was also noticed. Caspase3 and IGg were elevated compared to the control group in a dose dependant manner. treatment of the rats with Carnosine or melatonin. along with TiO2- NPs administration significantly improved most of the elevated biochemical markers. It was concluded that the use of Carnosine or melatonin could play a beneficial role against deleterious effects of TiO2- NPs

  10. Two-dimensional nanoparticle self-assembly using plasma-induced Ostwald ripening

    International Nuclear Information System (INIS)

    Tang, J; Photopoulos, P; Tsoukalas, D; Tserepi, A

    2011-01-01

    In this work, a novel Ag nanoparticle self-assembly process based on plasma-induced two-dimensional Ostwald ripening is demonstrated. Ag nanoparticles are deposited on p-doped Si substrates using a DC magnetron sputtering process. With the assistance of O 2 /Ar plasma treatment, different sizes and patterns of Ag nanoparticles are formed, due to the Ostwald ripening. The evolution of plasma-induced nanoparticle ripening is studied and a clear increase in particle size and a decrease in particle density are observed with increasing plasma treatment. From the experiments, it is concluded that the initial nanoparticle density and the plasma gas mixture (Ar/O 2 ratio) are important factors that affect the ripening process. The proposed plasma-directed Ag nanoparticle self-assembly provides a rapid method of tailoring the nanoparticle distribution on substrates, with potential applications in the fields of solar cells, biosensors, and catalysis.

  11. Anti-inflammatory and antioxidant effect of cerium dioxide nanoparticles immobilized on the surface of silica nanoparticles in rat experimental pneumonia.

    Science.gov (United States)

    Serebrovska, Z; Swanson, R J; Portnichenko, V; Shysh, A; Pavlovich, S; Tumanovska, L; Dorovskych, A; Lysenko, V; Tertykh, V; Bolbukh, Y; Dosenko, V

    2017-08-01

    A massage with the potent counter-inflammatory material, cerium dioxide nanoparticles, is promising and the antioxidant properties of CeO 2 are considered the main, if not the only, mechanism of this action. Nevertheless, the elimination of ceria nano-particles from the organism is very slow and there is a strong concern for toxic effect of ceria due to its accumulation. To overcome this problem, we engineered a combined material in which cerium nanoparticles were immobilized on the surface of silica nanoparticles (CeO 2 NP), which is shown to be easily removed from an organism and could be used as carriers for nano-ceria. In our study particle size was 220±5nm, Zeta-potential -4.5mV (in water), surface charge density -17.22μC/cm 2 (at pH 7). Thirty-six male Wistar rats, 5 months old and 250-290g were divided into four groups: 1) control; 2) CeO 2 NP treatment; 3) experimental pneumonia (i/p LPS injection, 1mg/kg); and 4) experimental pneumonia treated with CeO 2 NP (4 times during the study in dosage of 0.6mg/kg with an orogastric catheter). Gas exchange and pulmonary ventilation were measured four times: 0, 1, 3 and 24h after LPS injection in both untreated and CeO 2 NP-treated animals. The mRNA of TNF-α, Il-6, and CxCL2 were determined by RT-PCR. ROS-generation in blood plasma and lung tissue homogenates were measured by means of lucigenin- and luminol-enhanced chemiluminescence. Endotoxemia in the acute phase was associated with: (1) pathological changes in lung morphology; (2) increase of ROS generation; (3) enhanced expression of CxCL2; and (4) a gradual decrease of VO 2 and V E . CeO2 NP treatment of intact animals did not make any changes in all studied parameters except for a significant augmentation of VO 2 and V E. CeO 2 NP treatment of rats with pneumonia created positive changes in diminishing lung tissue injury, decreasing ROS generation in blood and lung tissue and decreasing pro-inflammatory cytokine expression (TNF-α, Il-6 and CxCL2). Oxygen

  12. Cuprous oxide nanoparticles selectively induce apoptosis of tumor cells

    Directory of Open Access Journals (Sweden)

    Wang Y

    2012-05-01

    Full Text Available Ye Wang,1,2,* Xiao-Yuan Zi,1,* Juan Su,1 Hong-Xia Zhang,1 Xin-Rong Zhang,3 Hai-Ying Zhu,1 Jian-Xiu Li,1 Meng Yin,3 Feng Yang,3 Yi-Ping Hu,11Department of Cell Biology, 2School of Clinical Medicine, 3Department of Pharmaceuticals, Second Military Medical University, Shanghai, People's Republic of China*Authors contributed equally.Abstract: In the rapid development of nanoscience and nanotechnology, many researchers have discovered that metal oxide nanoparticles have very useful pharmacological effects. Cuprous oxide nanoparticles (CONPs can selectively induce apoptosis and suppress the proliferation of tumor cells, showing great potential as a clinical cancer therapy. Treatment with CONPs caused a G1/G0 cell cycle arrest in tumor cells. Furthermore, CONPs enclosed in vesicles entered, or were taken up by mitochondria, which damaged their membranes, thereby inducing apoptosis. CONPs can also produce reactive oxygen species (ROS and initiate lipid peroxidation of the liposomal membrane, thereby regulating many signaling pathways and influencing the vital movements of cells. Our results demonstrate that CONPs have selective cytotoxicity towards tumor cells, and indicate that CONPs might be a potential nanomedicine for cancer therapy.Keywords: nanomedicine, selective cytotoxicity, apoptosis, cell cycle arrest, mitochondrion-targeted nanomaterials

  13. Ion beam induced effects on the ferromagnetism in Pd nanoparticles

    International Nuclear Information System (INIS)

    Kulriya, P. K.; Mehta, B. R.; Agarwal, D. C.; Agarwal, Kanika; Kumar, Praveen; Shivaprasad, S. M.; Avasthi, D. K.

    2012-01-01

    Present study demonstrates the role of metal-insulator interface and ion irradiation induced defects on the ferromagnetic properties of the non-magnetic materials. Magnetic properties of the Pd nanoparticles(NPs) embedded in the a-silica matrix synthesized using atom beam sputtering technique, were determined using SQUID magnetometry measurements which showed that ferromagnetic response of Pd increased by 3.5 times on swift heavy ion(SHI) irradiation. The ferromagnetic behavior of the as-deposited Pd NPs is due to strain induced by the surrounding matrix and modification in the electronic structure at the Pd-silica interface as revealed by insitu XRD and XPS investigations, respectively. The defects created by the SHI bombardment are responsible for enhancement of the magnetization in the Pd NPs.

  14. Functionalized nanoparticles for AMF-induced gene and drug delivery

    Science.gov (United States)

    Biswas, Souvik

    The properties and broad applications of nano-magnetic colloids have generated much interest in recent years. Specially, Fe3O4 nanoparticles have attracted a great deal of attention since their magnetic properties can be used for hyperthermia treatment or drug targeting. For example, enhanced levels of intracellular gene delivery can be achieved using Fe3O4 nano-vectors in the presence of an external magnetic field, a process known as 'magnetofection'. The low cytotoxicity, tunable particle size, ease of surface functionalization, and ability to generate thermal energy using an external alternating magnetic field (AMF) are properties have propelled Fe3O4 research to the forefront of nanoparticle research. The strategy of nanoparticle-mediated, AMF-induced heat generation has been used to effect intracellular hyperthermia. One application of this 'magnetic hyperthermia' is heat activated local delivery of a therapeutic effector (e.g.; drug or polynucleotide). This thesis describes the development of a magnetic nano-vector for AMF-induced, heat-activated pDNA and small molecule delivery. The use of heat-inducible vectors, such as heat shock protein ( hsp) genes, is a promising mode of gene therapy that would restrict gene expression to a local region by focusing a heat stimulus only at a target region. We thus aimed to design an Fe3O4 nanoparticle-mediated gene transfer vehicle for AMF-induced localized gene expression. We opted to use 'click' oximation techniques to assemble the magnetic gene transfer vector. Chapter 2 describes the synthesis, characterization, and transfection studies of the oxime ether lipid-based nano-magnetic vectors MLP and dMLP. The synthesis and characterization of a novel series of quaternary ammonium aminooxy reagents (2.1--2.4) is described. These cationic aminooxy compounds were loaded onto nanoparticles for ligation with carbonyl groups and also to impart a net positive charge on the nanoparticle surface. Our studies indicated that the

  15. Impact of anatase and rutile titanium dioxide nanoparticles on uptake carriers and efflux pumps in Caco-2 gut epithelial cells

    Science.gov (United States)

    Dorier, M.; Brun, E.; Veronesi, G.; Barreau, F.; Pernet-Gallay, K.; Desvergne, C.; Rabilloud, T.; Carapito, C.; Herlin-Boime, N.; Carrière, M.

    2015-04-01

    TiO2 microparticles are widely used in food products, where they are added as a white food colouring agent. This food additive contains a significant amount of nanoscale particles; still the impact of TiO2 nanoparticles (TiO2-NPs) on gut cells is poorly documented. Our study aimed at evaluating the impact of rutile and anatase TiO2-NPs on the main functions of enterocytes, i.e. nutrient absorption driven by solute-liquid carriers (SLC transporters) and protection against other xenobiotics driven by efflux pumps from the ATP-binding cassette (ABC) family. We show that acute exposure of Caco-2 cells to both anatase (12 nm) and rutile (20 nm) TiO2-NPs induce early upregulation of a battery of efflux pumps and nutrient transporters. In addition they cause overproduction of reactive oxygen species and misbalance redox repair systems, without inducing cell mortality or DNA damage. Taken together, these data suggest that TiO2-NPs may increase the functionality of gut epithelial cells, particularly their property to form a protective barrier against exogenous toxicants and to absorb nutrients.TiO2 microparticles are widely used in food products, where they are added as a white food colouring agent. This food additive contains a significant amount of nanoscale particles; still the impact of TiO2 nanoparticles (TiO2-NPs) on gut cells is poorly documented. Our study aimed at evaluating the impact of rutile and anatase TiO2-NPs on the main functions of enterocytes, i.e. nutrient absorption driven by solute-liquid carriers (SLC transporters) and protection against other xenobiotics driven by efflux pumps from the ATP-binding cassette (ABC) family. We show that acute exposure of Caco-2 cells to both anatase (12 nm) and rutile (20 nm) TiO2-NPs induce early upregulation of a battery of efflux pumps and nutrient transporters. In addition they cause overproduction of reactive oxygen species and misbalance redox repair systems, without inducing cell mortality or DNA damage. Taken

  16. Dissolution-Induced Nanowire Synthesis on Hot-Dip Galvanized Surface in Supercritical Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Aaretti Kaleva

    2017-07-01

    Full Text Available In this study, we demonstrate a rapid treatment method for producing a needle-like nanowire structure on a hot-dip galvanized sheet at a temperature of 50 °C. The processing method involved only supercritical carbon dioxide and water to induce a reaction on the zinc surface, which resulted in growth of zinc hydroxycarbonate nanowires into flower-like shapes. This artificial patina nanostructure predicts high surface area and offers interesting opportunities for its use in industrial high-end applications. The nanowires can significantly improve paint adhesion and promote electrochemical stability for organic coatings, or be converted to ZnO nanostructures by calcining to be used in various semiconductor applications.

  17. Nanoparticles Embedded in Amphiphilic Membranes for Carbon Dioxide Separation and Dehumidification.

    Science.gov (United States)

    Yong, Wai Fen; Ho, Yan Xun; Chung, Tai-Shung

    2017-10-23

    Polymers containing ethylene oxide (EO) groups have gained significant interest as the EO groups have favorable interactions with polar molecules such as H 2 O, quadrupolar molecules such as CO 2 , and metal ions. However, the main challenges of poly(ethylene oxide) (PEO) membranes are their weak mechanical properties and high crystallinity nature. The amphiphilic copolymer made from PEO terephthalate and poly(butylene terephthalate) (PEOT/PBT) comprises both hydrophilic and hydrophobic segments. The hydrophilic PEOT segment is thermosensitive, which facilities gas transports whereas the hydrophobic PBT segment is rigid, which provides mechanical robustness. This work demonstrates a new strategy to design amphiphilic mixed matrix membranes (MMMs) by incorporating zeolitic imidazolate framework, ZIF-71, into the PEOT/PBT copolymer. The resultant membrane shows an enhanced CO 2 permeability with an ideal CO 2 /N 2 selectivity surpassing the original PEOT/PBT and Robeson's Upper bound line. The nanoparticles-embedded amphiphilic membranes exhibit characteristics of high transparency and mechanical robustness. Mechanically strong composite hollow fiber membranes consisting of PEOT/PBT/ZIF-71 as the selective layer were also prepared. The resultant hollow fibers possess an excellent CO 2 permeance of 131 GPU (gas permeation units), CO 2 /N 2 selectivity of 52.6, H 2 O permeance of 9300 GPU and H 2 O/N 2 selectivity of 3700, showing great potential for industrial CO 2 capture and dehumidification. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Ambient redox synthesis of vanadium-doped manganese dioxide nanoparticles and their enhanced zinc storage properties

    Science.gov (United States)

    Alfaruqi, Muhammad Hilmy; Islam, Saiful; Mathew, Vinod; Song, Jinju; Kim, Sungjin; Tung, Duong Pham; Jo, Jeonggeun; Kim, Seokhun; Baboo, Joseph Paul; Xiu, Zhiliang; Kim, Jaekook

    2017-05-01

    In this work, we demonstrate the first use of a V-doped MnO2 nanoparticle electrode for zinc-ion battery (ZIB) applications. The V-doped MnO2 was prepared via a simple redox reaction and the X-ray diffraction studies confirmed the formation of pure MnO2, accompanied by an anisotropic expansion of MnO2 lattice, suggesting the incorporation of V-ions into the MnO2 framework. V doping of MnO2 not only increased the specific surface area but also improved the electronic conductivity. When Zn-storage properties were tested, the V-doped MnO2 electrode registered a higher discharge capacity of 266 mAh g-1 compared to 213 mAh g-1 for the pure MnO2 electrode. On prolonged cycling, the doped electrode retained 31% higher capacity than that of the bare MnO2 electrode and thereby demonstrated superior cycling performance. This study may pave the way towards understanding the enhancement of the energy storage properties via doping in electrodes of aqueous ZIB applications and also furthers the efforts for the practical realization of a potential eco-friendly battery system.

  19. Iron Oxide and Titanium Dioxide Nanoparticle Effects on Plant Performance and Root Associated Microbes

    Directory of Open Access Journals (Sweden)

    David J. Burke

    2015-10-01

    Full Text Available In this study, we investigated the effect of positively and negatively charged Fe3O4 and TiO2 nanoparticles (NPs on the growth of soybean plants (Glycine max. and their root associated soil microbes. Soybean plants were grown in a greenhouse for six weeks after application of different amounts of NPs, and plant growth and nutrient content were examined. Roots were analyzed for colonization by arbuscular mycorrhizal (AM fungi and nodule-forming nitrogen fixing bacteria using DNA-based techniques. We found that plant growth was significantly lower with the application of TiO2 as compared to Fe3O4 NPs. The leaf carbon was also marginally significant lower in plants treated with TiO2 NPs; however, leaf phosphorus was reduced in plants treated with Fe3O4. We found no effects of NP type, concentration, or charge on the community structure of either rhizobia or AM fungi colonizing plant roots. However, the charge of the Fe3O4 NPs affected both colonization of the root system by rhizobia as well as leaf phosphorus content. Our results indicate that the type of NP can affect plant growth and nutrient content in an agriculturally important crop species, and that the charge of these particles influences the colonization of the root system by nitrogen-fixing bacteria.

  20. Effect of titanium dioxide nanoparticle addition into orthodontic adhesive resin on enamel microhardness

    Science.gov (United States)

    Andriani, A.; Krisnawati; Purwanegara, M. K.

    2017-08-01

    White spots are an early sign of enamel demineralization, which may lead to development of dental caries. Enamel demineralization can be determined by examining the microhardness number of the enamel. Addition of antibacterial agents such as TiO2 nanoparticles into the orthodontic adhesive (TiO2 nanocomposite) is expected to prevent enamel demineralization. The objective of this study is to evaluate the effect of TiO2 nanocomposites in maintaining enamel microhardness around orthodontic brackets. The bracket was bonded to the premolar using Transbond XT (group 1), 1% TiO2 nanocomposites (group 2), and 2% TiO2 nanocomposites (group 3). Group 4 was the control group, and it was not given any treatment prior to the microhardness test. The samples of groups 1, 2, and 3 were soaked in BHI solution containing Streptococcus mutans, and then stored in an incubator at 37°C for 30 days. Demineralizations were determined on cross-sectioned tooth 100μm and 200μm cervical to the bracket by the Vickers microhardness test. The microhardness values were significantly different between every group, with the highest value obtained for control group, followed by the 2% TiO2 nanocomposite group, 1% TiO2 nanocomposite group, and then the Transbond XT group. The results of this study reveal that 2% TiO2 nanocomposites have the ability to maintain enamel microhardness around the orthodontic bracket.

  1. Effects of titanium dioxide nanoparticles derived from consumer products on the marine diatom Thalassiosira pseudonana.

    Science.gov (United States)

    Galletti, Andrea; Seo, Seokju; Joo, Sung Hee; Su, Chunming; Blackwelder, Pat

    2016-10-01

    Increased manufacture of TiO 2 nanoproducts has caused concern about the potential toxicity of these products to the environment and in public health. Identification and confirmation of the presence of TiO 2 nanoparticles derived from consumer products as opposed to industrial TiO 2 NPs warrant examination in exploring the significance of their release and resultant impacts on the environment. To this end, we examined the significance of the release of these particles and their toxic effect on the marine diatom algae Thalassiosira pseudonana. Our results indicate that nano-TiO 2 sunscreen and toothpaste exhibit more toxicity in comparison to industrial TiO 2 and inhibited the growth of the marine diatom T. pseudonana. This inhibition was proportional to the exposure time and concentrations of nano-TiO 2 . Our findings indicate a significant effect, and therefore, further research is warranted in evaluation and assessment of the toxicity of modified nano-TiO 2 derived from consumer products and their physicochemical properties.

  2. Turkevich method for silver/titanium dioxide nanoparticles with antimicrobial application in polymers systems;Obtencao de nanoparticulas de prata/dioxido de titanio pelo metodo Turkevich para aplicacoes antimicrobiais em matrizes polimericas

    Energy Technology Data Exchange (ETDEWEB)

    Olyveira, Gabriel Molina de; Pessan, Luiz Antonio, E-mail: gmolyveira@yahoo.com.b, E-mail: acarvalho@ufscar.b [Universidade Federal de Sao Carlos (PPG-CEM/UFSCar), SP (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Carvalho, Antonio Jose Felix de [Universidade Federal de Sao Carlos (UFSCar), Sorocaba, SP (Brazil)

    2009-07-01

    Titanium dioxide nanoparticles were covered with silver nanoparticles using Turkevich Method or citrate reduction method. Silver and titanium dioxide has proved antimicrobial properties then the nanocomposite can be successful incorporated in polymer systems. Silver nitrate was reduced by sodium citrate in the presence of poly(vinyl pyrrolidone)(PVP) resulting in nano-Ag/TiO{sub 2} stabilized suspension. It was tested ammonia hydroxide in the synthesis to avoid the nanoparticles growth. The Ag/TiO{sub 2} nanoparticles were characterized with X-ray diffraction (XRD), Scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). The best system of coloidal nanoparticles was that one with Poly(vinyl pyrrolidone) and ammonia in the synthesis. (author)

  3. Study of interaction between tin dioxide nanoparticle and 1,4-dihydroxy 2,3-dimethyl 9,10-anthraquinone sensitizer

    International Nuclear Information System (INIS)

    Suvetha Rani, J.; Sasirekha, V.; Ramakrishnan, V.

    2013-01-01

    The interaction between 1,4-dihydroxy 2,3-dimethyl 9,10-anthraquinone (DHDMAQ) and tin dioxide nanoparticle (SnO 2 NPs) has been investigated using optical absorption and emission techniques. Tin dioxide nanoparticles have been synthesized by chemical precipitation method. The experimental results reveal that the fluorescence intensity of 1,4-dihydroxy 2,3-dimethyl 9,10-anthraquinone has been quenched as the concentration of the SnO 2 NPs increased. The Stern–Volmer plot indicates that SnO 2 NPs have dynamic quenching efficiency on the fluorescence nature of DHDMAQ. The obtained value of the association constant infers that there is an association between DHDMAQ and the SnO 2 nanoparticles. -- Highlights: • The interaction between DHDMAQ and SnO 2 NPs has been investigated using optical absorption and emission techniques. • The fluorescence intensity of the fluorophore has been quenched as the concentration of the SnO 2 NPs increased. • The Stern–Volmer plot indicates that SnO 2 NPs have dynamic quenching efficiency on the fluorescence nature of DHDMAQ

  4. Curcumin Attenuates Hepatotoxicity Induced by Zinc Oxide Nanoparticles in Rats

    Directory of Open Access Journals (Sweden)

    Layasadat Khorsandi

    2016-06-01

    Full Text Available Background: Zinc oxide nanoparticles (NZnO are increasingly used in modern life. Most metal nanoparticles have adverse effects on the liver. Aims: To explore the protective action of curcumin (Cur against hepatotoxicity induced by NZnO in rats. Study Design: Animal experimentation. Methods: Control group animals received normal saline, while the Cur group animals were treated with 200 mg/kg of Cur orally for 21 days. NZnO-intoxicated rats received 50 mg/kg of NZnO for 14 days by gavage method. In the NZnO+Cur group, rats were pretreated with Cur for 7 days before NZnO administration. Plasma activities of Alanine aminotransferase (ALT, aspartate aminotransferase (AST and alkaline phosphatase (ALP were measured as biomarkers of hepatotoxicity. Hepatic levels of malondialdehyde (MDA and superoxide dismutase (SOD and glutathione peroxidase (GPx activities were measured for detection of oxidative stress in liver tissue. Histological changes and apoptosis in liver tissue were studied by using Hematoxylin-eosin staining and the transferase dUTP nick end labeling (TUNEL method. Results: NZnO induced a significant increase in plasma AST (2.8-fold, ALT (2.7-fold and ALP (1.97-fold activity in comparison to the control group (p<0.01. NZnO increased MDA content and reduced SOD and GPx activities. NZnO caused liver damage including centrilobular necrosis and microvesicular steatosis. The percentage of apoptosis in hepatocytes was increased in NZnO-treated rats (p<0.01. Pre-treatment of Cur significantly reduced lipid peroxidation (39%, increased SOD (156% and GPx (26% activities, and attenuated ALT (47%, AST (41% and ALP (30% activities. Pre-treatment with Cur also decreased the histology changes and apoptotic index of hepatocytes (p<0.05. Conclusion: These findings indicate that Cur effectively protects against NZnO-induced hepatotoxicity in rats. However, future studies are required to propose Cur as a potential protective agent against hepatotoxicity

  5. Interactions of ciprofloxacin (CIP), titanium dioxide (TiO{sub 2}) nanoparticles and natural organic matter (NOM) in aqueous suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Elke, E-mail: elke.fries@bgr.de [Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Bureau de Recherches Géologiques et Minières (BRGM), Orléans (France); Crouzet, Catherine; Michel, Caroline; Togola, Anne [Bureau de Recherches Géologiques et Minières (BRGM), Orléans (France)

    2016-09-01

    The aim of the present study was to investigate interactions of the antibiotic ciprofloxacin (CIP), titanium dioxide nanoparticles (TiO{sub 2} NP) and natural organic matter (NOM) in aqueous suspensions. The mean hydrodynamic diameter of particles of TiO{sub 2} NP and NOM in the suspensions ranged from 113 to 255 nm. During batch experiments the radioactivity resulting from {sup 14}CIP was determined in the filtrate (filter pore size 100 nm) by scintillation measurements. Up to 72 h, no significant sorption of NOM to TiO{sub 2} NP was observed at a TiO{sub 2} NP concentration of 5 mg/L. When the concentration of TiO{sub 2} NP was increased to 500 mg/L, a small amount of NOM of 9.5% ± 0.6% was sorbed at 72 h. The low sorption affinity of NOM on TiO{sub 2} NP surfaces could be explained by the negative charge of both components in alkaline media or by the low hydrophobicity of the NOM contents. At a TiO{sub 2} NP concentration of 5 mg L{sup −1}, the sorption of CIP on TiO{sub 2} NP was insignificant (TiO{sub 2} NP/CIP ratio: 10). When the TiO{sub 2} NP/CIP ratio was increased to 1000, a significant amount of 53.6% ± 7.2% of CIP was sorbed on TiO{sub 2} NP under equilibrium conditions at 64 h. In alkaline media, CIP is present mainly as zwitterions which have an affinity to sorb on negatively charged TiO{sub 2} NP surfaces. The sorption of CIP on TiO{sub 2} NP in the range of TiO{sub 2} NP concentrations currently estimated for municipal wastewater treatment plants is estimated to be rather low. The Freundlich sorption coefficients (K{sub F}) in the presence of NOM of 2167 L{sup n} mg mg{sup −n} kg{sup −1} was about 10 times lower than in the absence of NOM. This is an indication that the particle fraction of NOM < 100 nm could play a role as a carrier for ionic organic micro-pollutants as CIP. - Highlights: • Ciprofloxacine (CIP) and titanium dioxide nanoparticles (TiO{sub 2} NP) interact. • Organic carbon (OC) could influence such interactions. • Batch

  6. Characterization of titanium dioxide nanoparticles modified with polyacrylic acid and H2O2 for use as a novel radiosensitizer.

    Science.gov (United States)

    Morita, Kenta; Miyazaki, Serika; Numako, Chiya; Ikeno, Shinya; Sasaki, Ryohei; Nishimura, Yuya; Ogino, Chiaki; Kondo, Akihiko

    2016-12-01

    An induction of polyacrylic acid-modified titanium dioxide with hydrogen peroxide nanoparticles (PAA-TiO 2 /H 2 O 2 NPs) to a tumor exerted a therapeutic enhancement of X-ray irradiation in our previous study. To understand the mechanism of the radiosensitizing effect of PAA-TiO 2 /H 2 O 2 NPs, analytical observations that included DLS, FE-SEM, FT-IR, XAFS, and Raman spectrometry were performed. In addition, highly reactive oxygen species (hROS) which PAA-TiO 2 /H 2 O 2 NPs produced with X-ray irradiation were quantified by using a chemiluminescence method and a EPR spin-trapping method. We found that PAA-TiO 2 /H 2 O 2 NPs have almost the same characteristics as PAA-TiO 2 . Surprisingly, there were no significant differences in hROS generation. However, the existence of H 2 O 2 was confirmed in PAA-TiO 2 /H 2 O 2 NPs, because spontaneous hROS production was observed w/o X-ray irradiation. In addition, PAA-TiO 2 /H 2 O 2 NPs had a curious characteristic whereby they absorbed H 2 O 2 molecules and released them gradually into a liquid phase. Based on these results, the H 2 O 2 was continuously released from PAA-TiO 2 /H 2 O 2 NPs, and then released H 2 O 2 assumed to be functioned indirectly as a radiosensitizing factor.

  7. NMR-based metabonomic study of the sub-acute toxicity of titanium dioxide nanoparticles in rats after oral administration

    Science.gov (United States)

    Bu, Qian; Yan, Guangyan; Deng, Pengchi; Peng, Feng; Lin, Hongjun; Xu, Youzhi; Cao, Zhixing; Zhou, Tian; Xue, Aiqin; Wang, Yanli; Cen, Xiaobo; Zhao, Ying-Lan

    2010-03-01

    As titanium dioxide nanoparticles (TiO2 NPs) are widely used commercially, their potential toxicity on human health has attracted particular attention. In the present study, the oral toxicological effects of TiO2 NPs (dosed at 0.16, 0.4 and 1 g kg - 1, respectively) were investigated using conventional approaches and metabonomic analysis in Wistar rats. Serum chemistry, hematology and histopathology examinations were performed. The urine and serum were investigated by 1H nuclear magnetic resonance (NMR) using principal components and partial least squares discriminant analysis. The metabolic signature of urinalysis in TiO2 NP-treated rats showed increases in the levels of taurine, citrate, hippurate, histidine, trimethylamine-N-oxide (TMAO), citrulline, α-ketoglutarate, phenylacetylglycine (PAG) and acetate; moreover, decreases in the levels of lactate, betaine, methionine, threonine, pyruvate, 3-D-hydroxybutyrate (3-D-HB), choline and leucine were observed. The metabonomics analysis of serum showed increases in TMAO, choline, creatine, phosphocholine and 3-D-HB as well as decreases in glutamine, pyruvate, glutamate, acetoacetate, glutathione and methionine after TiO2 NP treatment. Aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) were elevated and mitochondrial swelling in heart tissue was observed in TiO2 NP-treated rats. These findings indicate that disturbances in energy and amino acid metabolism and the gut microflora environment may be attributable to the slight injury to the liver and heart caused by TiO2 NPs. Moreover, the NMR-based metabolomic approach is a reliable and sensitive method to study the biochemical effects of nanomaterials.

  8. NMR-based metabonomic study of the sub-acute toxicity of titanium dioxide nanoparticles in rats after oral administration

    International Nuclear Information System (INIS)

    Bu Qian; Lin Hongjun; Xu Youzhi; Cao Zhixing; Zhou Tian; Zhao Yinglan; Yan Guangyan; Cen Xiaobo; Deng Pengchi; Peng Feng; Xue Aiqin; Wang Yanli

    2010-01-01

    As titanium dioxide nanoparticles (TiO 2 NPs) are widely used commercially, their potential toxicity on human health has attracted particular attention. In the present study, the oral toxicological effects of TiO 2 NPs (dosed at 0.16, 0.4 and 1 g kg -1 , respectively) were investigated using conventional approaches and metabonomic analysis in Wistar rats. Serum chemistry, hematology and histopathology examinations were performed. The urine and serum were investigated by 1 H nuclear magnetic resonance (NMR) using principal components and partial least squares discriminant analysis. The metabolic signature of urinalysis in TiO 2 NP-treated rats showed increases in the levels of taurine, citrate, hippurate, histidine, trimethylamine-N-oxide (TMAO), citrulline, α-ketoglutarate, phenylacetylglycine (PAG) and acetate; moreover, decreases in the levels of lactate, betaine, methionine, threonine, pyruvate, 3-D-hydroxybutyrate (3-D-HB), choline and leucine were observed. The metabonomics analysis of serum showed increases in TMAO, choline, creatine, phosphocholine and 3-D-HB as well as decreases in glutamine, pyruvate, glutamate, acetoacetate, glutathione and methionine after TiO 2 NP treatment. Aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) were elevated and mitochondrial swelling in heart tissue was observed in TiO 2 NP-treated rats. These findings indicate that disturbances in energy and amino acid metabolism and the gut microflora environment may be attributable to the slight injury to the liver and heart caused by TiO 2 NPs. Moreover, the NMR-based metabolomic approach is a reliable and sensitive method to study the biochemical effects of nanomaterials.

  9. NMR-based metabonomic study of the sub-acute toxicity of titanium dioxide nanoparticles in rats after oral administration

    Energy Technology Data Exchange (ETDEWEB)

    Bu Qian; Lin Hongjun; Xu Youzhi; Cao Zhixing; Zhou Tian; Zhao Yinglan [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Yan Guangyan; Cen Xiaobo [National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Deng Pengchi [Analytical and Testing Center, Sichuan University, Chengdu 610041 (China); Peng Feng [Department of Thoracic Oncology of Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Xue Aiqin [Institute of Bioengineering, Zhejiang Sci-Tech University Road 2, Xiasha, Hangzhou 310018 (China); Wang Yanli, E-mail: alancenxb@sina.com [Tianjin Children' s Hospital, Tianjin 300074 (China)

    2010-03-26

    As titanium dioxide nanoparticles (TiO{sub 2} NPs) are widely used commercially, their potential toxicity on human health has attracted particular attention. In the present study, the oral toxicological effects of TiO{sub 2} NPs (dosed at 0.16, 0.4 and 1 g kg{sup -1}, respectively) were investigated using conventional approaches and metabonomic analysis in Wistar rats. Serum chemistry, hematology and histopathology examinations were performed. The urine and serum were investigated by {sup 1}H nuclear magnetic resonance (NMR) using principal components and partial least squares discriminant analysis. The metabolic signature of urinalysis in TiO{sub 2} NP-treated rats showed increases in the levels of taurine, citrate, hippurate, histidine, trimethylamine-N-oxide (TMAO), citrulline, {alpha}-ketoglutarate, phenylacetylglycine (PAG) and acetate; moreover, decreases in the levels of lactate, betaine, methionine, threonine, pyruvate, 3-D-hydroxybutyrate (3-D-HB), choline and leucine were observed. The metabonomics analysis of serum showed increases in TMAO, choline, creatine, phosphocholine and 3-D-HB as well as decreases in glutamine, pyruvate, glutamate, acetoacetate, glutathione and methionine after TiO{sub 2} NP treatment. Aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) were elevated and mitochondrial swelling in heart tissue was observed in TiO{sub 2} NP-treated rats. These findings indicate that disturbances in energy and amino acid metabolism and the gut microflora environment may be attributable to the slight injury to the liver and heart caused by TiO{sub 2} NPs. Moreover, the NMR-based metabolomic approach is a reliable and sensitive method to study the biochemical effects of nanomaterials.

  10. Effects of titanium dioxide nanoparticles isolated from confectionery products on the metabolic stress pathway in human lung fibroblast cells.

    Science.gov (United States)

    Periasamy, Vaiyapuri Subbarayan; Athinarayanan, Jegan; Al-Hadi, Ahmed M; Juhaimi, Fahad Al; Alshatwi, Ali A

    2015-04-01

    Titanium dioxide (TiO2) is a common additive in many foods, pigments, personal care products, and other consumer products used in daily life. Despite the widespread use of nanoscale TiO2 and composites of nanoscale TiO2 in the food industry, there is a serious lack of awareness of the toxicity of TiO2 nanoparticles (NPs) among consumers and manufacturers. There is an urgent need for toxicological studies of TiO2 NPs. TiO2 food additives separated from marketed foods were characterized by transmission electron microscopy. In addition, the effects of TiO2 NPs on metabolic stress in WI-38 cells were analyzed. Cell viability, total ROS, mitochondrial transmembrane potential (ΔψM), cell cycle, and metabolism-related gene expression were analyzed. The results indicate that TiO2 NPs have a significant concentration-dependent toxic effect in lung cells. The ΔψM, the intracellular ROS level, and the stages of the WI-38 cell cycle were altered by increasing TiO2 concentrations after exposure for 24 and 48 h relative to the control. Cytochrome P450 1A, GSTM3, and glutathione S-transferase A4 upregulation in response to the TiO2 NPs was observed. These findings suggest that the toxicity of TiO2 from confectionery products in WI-38 cells may be mediated through an increase in oxidative stress. The results of this study clearly demonstrate the nanotoxicological effects of TiO2 on WI-38 cells and will be useful for nanotoxicological indexing.

  11. Agglomeration and sedimentation of titanium dioxide nanoparticles (n-TiO{sub 2}) in synthetic and real waters

    Energy Technology Data Exchange (ETDEWEB)

    Brunelli, Andrea [University Ca' Foscari Venice, Department of Environmental Sciences, Informatics and Statistics (Italy); Pojana, Giulio [University Ca' Foscari Venice, Department of Philosophy and Cultural Heritage (Italy); Callegaro, Sarah; Marcomini, Antonio, E-mail: marcom@unive.it [University Ca' Foscari Venice, Department of Environmental Sciences, Informatics and Statistics (Italy)

    2013-06-15

    The recent detection of titanium dioxide nanoparticles (n-TiO{sub 2}) in wastewaters raised concerns about its fate in the aquatic environment, which is related to its mobility through water bodies. Laboratory experiments of n-TiO{sub 2} (particle size distribution: 10-65 nm) dispersed into both synthetic and real aqueous solutions under environmentally realistic concentrations (0.01, 0.1, 1 and 10 mg/l) were conducted over a time of 50 h to mimic duration of ecotoxicological tests. Agglomeration and sedimentation behaviour were measured under controlled conditions of salinity (0-35 Per-Mille-Sign ), ionic composition and strength, pH and dissolved organic carbon (DOC). Physico-chemical parameters and particle agglomeration in the dispersions were investigated by transmission electron microscopy, Brunauer, Emmett and Teller method and dynamic light scattering. A fluorescence spectrophotometer operating in the nephelometric mode was employed to obtain the sedimentation rates of n-TiO{sub 2}. The overall results showed that agglomeration and sedimentation of n-TiO{sub 2} were affected mainly by the initial concentration. Sedimentation data fitted satisfactorily (R{sup 2} in the range of 0.74-0.98; average R{sup 2}: 0.90) with a first-order kinetic equation.The settling rate constant, k, increased by approx. one order of magnitude by moving from the lowest to the highest concentration, resulting very similar especially for all dispersions at 1(k = 8 Multiplication-Sign 10{sup -6} s{sup -1}) and 10 mg/l (k = 2 Multiplication-Sign 10{sup -5} s{sup -1}) n-TiO{sub 2}, regardless the ionic strength and composition of dispersions. The implication of these results on toxicological testing is discussed.

  12. Aggregation and transport of rutile titanium dioxide nanoparticles with montmorillonite and diatomite in the presence of phosphate in porous sand.

    Science.gov (United States)

    Guo, Peng; Xu, Nan; Li, Duo; Huangfu, Xinxing; Li, Zuling

    2018-08-01

    Crop soil is inevitably contaminated by the excess of phosphate (P) fertilizers. A large amount of nanoparticle titanium dioxide (nTiO 2 ) entered soils as well due to the wide use of engineered nanomaterials. It is of great urgency and a high priority to investigate the mechanisms of nTiO 2 deposition with the presence of P in crop soils. This study investigated the transport behavior of (1.0 g L -1 ) rutile nTiO 2 with two representative clay particles (montmorillonite or diatomite) in the presence of P through the saturated quartz sand. In 10 mM NaCl electrolyte solution at pH 6.0, the recovery percentage of nTiO 2 was 36.3% from sand column. Nevertheless, it was reduced to 18.6% and 11.1% while montmorillonite and diatomite present in suspensions, respectively. Obviously, the improvement of nTiO 2 retention in sand was more pronounced by diatomite than montmorillonite. The likely mechanism for this result was that large aggregates were formed due to the attachment of nTiO 2 to montmorillonite and diatomite. Moreover, the surface of diatomite with the larger hydrodynamic radius was less negatively charged by comparison with montmorillonite. However, this phenomenon disappeared with the addition of P. P adsorption increases the repulsive force between particles and sand and the fast release of attached nTiO 2 -montmorillonite and diatomite from sand. The two-site kinetic retention model and the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory suggested that the combination of k 1/ k 1d , k 2 and secondary minimum energy can be used to accurately describe the attachment of nTiO 2 -montmorillonite and diatomite to sand in the presence of P. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Ultrasound assisted enzymatic hydrolysis for isolating titanium dioxide nanoparticles from bivalve mollusk before sp-ICP-MS.

    Science.gov (United States)

    Taboada-López, María Vanesa; Iglesias-López, Sara; Herbello-Hermelo, Paloma; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2018-08-14

    Applicability of single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) using dwell times equal to or shorter than 100 μs has been tested for assessing titanium dioxide nanoparticles (TiO 2 NPs) in bivalve mollusks. TiO 2 NPs isolation from fresh mollusk tissues was achieved by ultrasound assisted enzymatic hydrolysis procedure using a pancreatin/lipase mixture. Optimum extraction conditions imply ultrasonication (60% amplitude) for 10 min, and 7.5 mL of a solution containing 3.0 g L -1 of pancreatin and lipase (pH 7.4). The developed method was found to be repeatable (repeatability of 17% for the over-all procedure, TiO 2 NPs concentration of 5.33 × 10 7  ± 8.89 × 10 6 , n = 11), showing a limit of detection of 5.28 × 10 6 NPs g -1 , and a limit of detection in size of 24.4-30.4 nm, based on the 3σ criteria, and on the 3σ/5 σ criteria, respectively. The analytical recovery within the 90-99% range (use of TiO 2 NPs standards of 50 nm at 7 and 14 μg L -1 as Ti). Several bivalve mollusks (clams, cockles, mussels, razor clams, oysters and variegated scallops) were analyzed for total titanium (ICP-MS after microwave assisted acid digestion), and for TiO 2 NPs by the proposed method. TiO 2 NPs concentrations were within the 2.36 × 10 7 -1.25 × 10 8 NPs g -1 range, and the most frequent sizes were from 50 to 70 nm. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Agglomeration and sedimentation of titanium dioxide nanoparticles (n-TiO2) in synthetic and real waters

    International Nuclear Information System (INIS)

    Brunelli, Andrea; Pojana, Giulio; Callegaro, Sarah; Marcomini, Antonio

    2013-01-01

    The recent detection of titanium dioxide nanoparticles (n-TiO 2 ) in wastewaters raised concerns about its fate in the aquatic environment, which is related to its mobility through water bodies. Laboratory experiments of n-TiO 2 (particle size distribution: 10–65 nm) dispersed into both synthetic and real aqueous solutions under environmentally realistic concentrations (0.01, 0.1, 1 and 10 mg/l) were conducted over a time of 50 h to mimic duration of ecotoxicological tests. Agglomeration and sedimentation behaviour were measured under controlled conditions of salinity (0–35 ‰), ionic composition and strength, pH and dissolved organic carbon (DOC). Physico-chemical parameters and particle agglomeration in the dispersions were investigated by transmission electron microscopy, Brunauer, Emmett and Teller method and dynamic light scattering. A fluorescence spectrophotometer operating in the nephelometric mode was employed to obtain the sedimentation rates of n-TiO 2 . The overall results showed that agglomeration and sedimentation of n-TiO 2 were affected mainly by the initial concentration. Sedimentation data fitted satisfactorily (R 2 in the range of 0.74–0.98; average R 2 : 0.90) with a first-order kinetic equation.The settling rate constant, k, increased by approx. one order of magnitude by moving from the lowest to the highest concentration, resulting very similar especially for all dispersions at 1(k = 8 × 10 −6 s −1 ) and 10 mg/l (k = 2 × 10 −5 s −1 ) n-TiO 2 , regardless the ionic strength and composition of dispersions. The implication of these results on toxicological testing is discussed.

  15. Ambient redox synthesis of vanadium-doped manganese dioxide nanoparticles and their enhanced zinc storage properties

    Energy Technology Data Exchange (ETDEWEB)

    Alfaruqi, Muhammad Hilmy; Islam, Saiful; Mathew, Vinod; Song, Jinju; Kim, Sungjin; Tung, Duong Pham; Jo, Jeonggeun; Kim, Seokhun; Baboo, Joseph Paul; Xiu, Zhiliang; Kim, Jaekook, E-mail: jaekook@chonnam.ac.kr

    2017-05-15

    Highlights: • The V-doped MnO{sub 2} was prepared by a simple ambient redox reaction. • The V-doped MnO{sub 2} was tested as a cathode in aqueous zinc-ion batteries (ZIBs). • The doped cathode showed better zinc-storage properties than the bare cathode. • The present study facilitates the development of safe and reliable aqueous ZIBs. - Abstract: In this work, we demonstrate the first use of a V-doped MnO{sub 2} nanoparticle electrode for zinc-ion battery (ZIB) applications. The V-doped MnO{sub 2} was prepared via a simple redox reaction and the X-ray diffraction studies confirmed the formation of pure MnO{sub 2}, accompanied by an anisotropic expansion of MnO{sub 2} lattice, suggesting the incorporation of V-ions into the MnO{sub 2} framework. V doping of MnO{sub 2} not only increased the specific surface area but also improved the electronic conductivity. When Zn-storage properties were tested, the V-doped MnO{sub 2} electrode registered a higher discharge capacity of 266 mAh g{sup −1} compared to 213 mAh g{sup −1} for the pure MnO{sub 2} electrode. On prolonged cycling, the doped electrode retained 31% higher capacity than that of the bare MnO{sub 2} electrode and thereby demonstrated superior cycling performance. This study may pave the way towards understanding the enhancement of the energy storage properties via doping in electrodes of aqueous ZIB applications and also furthers the efforts for the practical realization of a potential eco-friendly battery system.

  16. Enhanced antimicrobial efficacy of thermal-reduced silver nanoparticles supported by titanium dioxide.

    Science.gov (United States)

    Chen, Yen-Chi; Yu, Kuo-Pin

    2017-06-01

    The antimicrobial efficacy of silver nanoparticles (AgNPs) is influenced by many factors, including the particle size, AgNP oxidation state and support materials. In this study, AgNPs are synthesized and supported by two types of TiO 2 powders (P25 and Merck TiO 2 ) using two heat-treatment temperatures (120 and 200°C). The formation of well-dispersed AgNPs with diameters ranging from 3.2 to 5.7nm was confirmed using transmission electron microscopy. X-ray photoelectron spectroscopy and X-ray diffraction indicated that the majority of the AgNPs were reduced from Ag + to Ag 0 at 200°C. The AgNP antimicrobial activity was determined by the zone of inhibition against three fungi, A. niger, P. spinulosum and S. chartarum, and two bacteria, E. coli (Gram-negative) and S. epidermidis (Gram-positive). The antimicrobial activity of metallic AgNPs was more pronounced than that of silver nitrate and some antimicrobial drugs. The AgNPs exhibited optimal antimicrobial efficacy when the AgNP dispersion on the surface of TiO 2 was in the region between 0.2 and 0.7μg-Ag/m 2 . The minimum (critical) AgNP concentrations needed to inhibit the growth of bacteria (E. coli) and fungi (A. niger) were 13.48 and 25.4μg/mL, respectively. The results indicate that AgNPs/TiO 2 nanocomposites are a promising disinfectant against both bacteria and fungi. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Effect of carbon dioxide inhalation on pulmonary hypertension induced by increased blood flow and hypoxia

    Directory of Open Access Journals (Sweden)

    I-Chun Chuang

    2011-08-01

    Full Text Available There is now increasing evidence from the experimental and clinical setting that therapeutic hypercapnia from intentionally inspired carbon dioxide (CO2 or lower tidal volume might be a beneficial adjunct to the strategies of mechanical ventilation in critical illness. Although previous reports indicate that CO2 exerts a beneficial effect in the lungs, the pulmonary vascular response to hypercapnia under various conditions remains to be clarified. The purpose of the present study is to characterize the pulmonary vascular response to CO2 under the different conditions of pulmonary hypertension secondary to increased pulmonary blood flow and secondary to hypoxic pulmonary vasoconstriction. Isolated rat lung (n = 32 was used to study (1 the vasoactive action of 5% CO2 in either N2 (hypoxic-hypercapnia or air (normoxic-hypercapnia at different pulmonary arterial pressure levels induced by graded speed of perfusion flow and (2 the role of nitric oxide (NO in mediating the pulmonary vascular response to hypercapnia, hypoxia, and flow-associated pulmonary hypertension. The results indicated that inhaled CO2 reversed pulmonary hypertension induced by hypoxia but not by flow alteration. Endogenous NO attenuates hypoxic pulmonary vasoconstriction but does not augment the CO2-induced vasodilatation. Acute change in blood flow does not alter the endogenous NO production.

  18. Effects of prenatal exposure to nanoparticles titanium dioxide and carbon black on female germline DNA stability

    DEFF Research Database (Denmark)

    Boisen, Anne Mette Zenner

    Particulate air pollution has been associated with an increased risk of cardiovascular disease and cancer in humans. Air pollution may also adversely affect pregnancy outcome and the integrity of sperm cells DNA. Animal studies have shown that inhalation of air particulates can induce mutations...... in premeiotic sperm cells. The investigation of potential mutagenic risk is of outmost importance, as it may lead to cancer. Furthermore, heritable mutations may be passed on to descendents and thereby pose a permanent genetic risk to the population. The nanosized fraction of particulate air pollution has...... are needed. Expanded simple tandem repeat (ESTR) loci in mice are sensitive markers of mutagenic effects resulting from environmental exposures; Studies on adult mice have revealed that while particulate air pollution induced ESTR mutations in premeiotic sperm cells, the female germline was not affected...

  19. Quantitative biokinetic analysis of radioactively labelled, inhaled Titanium dioxide Nanoparticles in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Kreyling, Wolfgang G.; Wenk, Alexander; Semmler-Behnke, Manuela [Helmholtz Zentrum Muenchen, Deutsches Forschungszentrum fuer Gesundheit und Umwelt GmbH (Germany). Inst. fuer Lungenbiologie und Erkrankungen, Netzwerk Nanopartikel und Gesundheit

    2010-09-15

    The aim of this project was the determination of the biokinetics of TiO{sub 2} nanoparticles (NP) in the whole body of healthy adult rats after NP administration to the respiratory tract - either via inhalation or instillation. We developed an own methodology to freshly synthesize and aerosolize TiO{sub 2}-NP in our lab for the use of inhalation studies. These NP underwent a detailed physical and chemical characterization providing pure polycrystalline anatase TiO{sub 2}-NP of about 20 nm (geometric standard deviation 1.6) and a specific surface area of 270 m{sup 2}/g. In addition, we developed techniques for sufficiently stable radioactive {sup 48}V labelling of the TiO{sub 2} NP. The kinetics of solubility of {sup 48}V was thoroughly determined. The methodology of quantitative biokinetics allows for a quantitative balance of the retained and excreted NP in control of the administered NP dose and provides a much more precise determination of NP fractions and concentrations of NP in organs and tissues of interest as compared to spotting biokinetics studies. Small fractions of TiO{sub 2}-NP translocate across the air-blood-barrier and accumulate in secondary target organs, soft tissue and skeleton. The amount of translocated TiO{sub 2}-NP is approximately 2% of TiO{sub 2}-NP deposited in the lungs. A prominent fraction of these translocated TiO{sub 2}-NP was found in the remainder. Smaller amounts of TiO{sub 2}-NP accumulate in secondary organs following particular kinetics. TiO{sub 2}-NP translocation was grossly accomplished within the first 2-4 hours after inhalation followed by retention in all organs and tissues studied without any detectable clearance of these biopersistent TiO{sub 2}-NP within 28 days. Therefore, our data suggest crossing of the air-blood-barrier of the lungs and subsequent accumulation in secondary organs and tissues depends on the NP material and its physico-chemical properties. Furthermore, we extrapolate that during repeated or chronic

  20. Quantitative biokinetic analysis of radioactively labelled, inhaled Titanium dioxide Nanoparticles in a rat model

    International Nuclear Information System (INIS)

    Kreyling, Wolfgang G.; Wenk, Alexander; Semmler-Behnke, Manuela

    2010-01-01

    The aim of this project was the determination of the biokinetics of TiO 2 nanoparticles (NP) in the whole body of healthy adult rats after NP administration to the respiratory tract - either via inhalation or instillation. We developed an own methodology to freshly synthesize and aerosolize TiO 2 -NP in our lab for the use of inhalation studies. These NP underwent a detailed physical and chemical characterization providing pure polycrystalline anatase TiO 2 -NP of about 20 nm (geometric standard deviation 1.6) and a specific surface area of 270 m 2 /g. In addition, we developed techniques for sufficiently stable radioactive 48 V labelling of the TiO 2 NP. The kinetics of solubility of 48 V was thoroughly determined. The methodology of quantitative biokinetics allows for a quantitative balance of the retained and excreted NP in control of the administered NP dose and provides a much more precise determination of NP fractions and concentrations of NP in organs and tissues of interest as compared to spotting biokinetics studies. Small fractions of TiO 2 -NP translocate across the air-blood-barrier and accumulate in secondary target organs, soft tissue and skeleton. The amount of translocated TiO 2 -NP is approximately 2% of TiO 2 -NP deposited in the lungs. A prominent fraction of these translocated TiO 2 -NP was found in the remainder. Smaller amounts of TiO 2 -NP accumulate in secondary organs following particular kinetics. TiO 2 -NP translocation was grossly accomplished within the first 2-4 hours after inhalation followed by retention in all organs and tissues studied without any detectable clearance of these biopersistent TiO 2 -NP within 28 days. Therefore, our data suggest crossing of the air-blood-barrier of the lungs and subsequent accumulation in secondary organs and tissues depends on the NP material and its physico-chemical properties. Furthermore, we extrapolate that during repeated or chronic exposure to insoluble NP the translocated fraction of NP will

  1. Chitosan nanoparticles from marine squid protect liver cells against N-diethylnitrosoamine-induced hepatocellular carcinoma.

    Science.gov (United States)

    Subhapradha, Namasivayam; Shanmugam, Vairamani; Shanmugam, Annaian

    2017-09-01

    Rationale of this study was framed to investigate the protective effect and anti-cancer property of nanoparticles based on chitosan isolated from squid, Sepioteuthis lessoniana, on hepatic cells in N-Nitrosodiethylamine-induced hepatocellular carcinoma in rats. The results conferred that the chitosan nanoparticle supplementation had a protective effect on liver cells by reducing the levels of marker enzymes and bilirubin and thus increasing the albumin levels. The level of reduced glutathione, ascorbic acid and α-tocopherol significantly increased in both post- and pre-treatment with chitosan nanoparticles. The levels of antioxidant enzymes were enhanced and lipid peroxidation products were diminished while treating nitrosodiethylamine-induced hepatocellular carcinoma with chitosan nanoparticles. Supplementation of chitosan nanoparticles had potent anti-hyperlipidemic property that was evidenced by monitoring the serum lipid levels and its components. Animals pre-treated with chitosan nanoparticles along with nitrosodiethylamine showed a significant reduction in the total cholesterol and triglycerides levels with increase in the levels of phospholipids and free fatty acids. Chitosan nanoparticles treated rats showed significant increment in high-density lipoprotein cholesterol and reduction in low-density lipoprotein and very low-density lipoprotein cholesterol when compared with levels in nitrosodiethylamine-induced hepatocellular carcinoma. Nitrosodiethylamine-induced carcinoma changes on circulation and hepatic antioxidant defense mechanism were regulated by chitosan nanoparticles, concluding that the chitosan nanoparticles have a potent protective effect on liver cells which might be due to its robust antioxidant and anti-lipidemic property. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Oxidative stress induced by cerium oxide nanoparticles in cultured BEAS-2B cells

    International Nuclear Information System (INIS)

    Park, Eun-Jung; Choi, Jinhee; Park, Young-Kwon; Park, Kwangsik

    2008-01-01

    Cerium oxide nanoparticles of different sizes (15, 25, 30, 45 nm) were prepared by the supercritical synthesis method, and cytotoxicity was evaluated using cultured human lung epithelial cells (BEAS-2B). Exposure of the cultured cells to nanoparticles (5, 10, 20, 40 μg/ml) led to cell death, ROS increase, GSH decrease, and the inductions of oxidative stress-related genes such as heme oxygenase-1, catalase, glutathione S-transferase, and thioredoxin reductase. The increased ROS by cerium oxide nanoparticles triggered the activation of cytosolic caspase-3 and chromatin condensation, which means that cerium oxide nanoparticles exert cytotoxicity by an apoptotic process. Uptake of the nanoparticles to the cultured cells was also tested. It was observed that cerium oxide nanoparticles penetrated into the cytoplasm and located in the peri-region of the nucleus as aggregated particles, which may induce the direct interaction between nanoparticles and cellular molecules to cause adverse cellular responses

  3. Silver nanoparticles induce endoplasmatic reticulum stress response in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Christen, Verena [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Capelle, Martinus [Crucell, P.O. Box 2048, NL-2301 Leiden (Netherlands); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology Zürich, Department of Environmental Systems Science, CH-8092 Zürich (Switzerland)

    2013-10-15

    Silver nanoparticles (AgNPs) find increasing applications, and therefore humans and the environment are increasingly exposed to them. However, potential toxicological implications are not sufficiently known. Here we investigate effects of AgNPs (average size 120 nm) on zebrafish in vitro and in vivo, and compare them to human hepatoma cells (Huh7). AgNPs are incorporated in zebrafish liver cells (ZFL) and Huh7, and in zebrafish embryos. In ZFL cells AgNPs lead to induction of reactive oxygen species (ROS), endoplasmatic reticulum (ER) stress response, and TNF-α. Transcriptional alterations also occur in pro-apoptotic genes p53 and Bax. The transcriptional profile differed in ZFL and Huh7 cells. In ZFL cells, the ER stress marker BiP is induced, concomitant with the ER stress marker ATF-6 and spliced XBP-1 after 6 h and 24 h exposure to 0.5 g/L and 0.05 g/L AgNPs, respectively. This indicates the induction of different pathways of the ER stress response. Moreover, AgNPs induce TNF-α. In zebrafish embryos exposed to 0.01, 0.1, 1 and 5 mg/L AgNPs hatching was affected and morphological defects occurred at high concentrations. ER stress related gene transcripts BiP and Synv are significantly up-regulated after 24 h at 0.1 and 5 mg/L AgNPs. Furthermore, transcriptional alterations occurred in the pro-apoptotic genes Noxa and p21. The ER stress response was strong in ZFL cells and occurred in zebrafish embryos as well. Our data demonstrate for the first time that AgNPs lead to induction of ER stress in zebrafish. The induction of ER stress can have several consequences including the activation of apoptotic and inflammatory pathways. - Highlights: • Effects of silver nanoparticles (120 nm AgNPs) are investigated in zebrafish. • AgNPs induce all ER stress reponses in vitro in zebrafish liver cells. • AgNPs induce weak ER stress in zebrafish embryos. • AgNPs induce oxidative stress and transcripts of pro-apoptosis genes.

  4. Silver nanoparticles induce endoplasmatic reticulum stress response in zebrafish

    International Nuclear Information System (INIS)

    Christen, Verena; Capelle, Martinus; Fent, Karl

    2013-01-01

    Silver nanoparticles (AgNPs) find increasing applications, and therefore humans and the environment are increasingly exposed to them. However, potential toxicological implications are not sufficiently known. Here we investigate effects of AgNPs (average size 120 nm) on zebrafish in vitro and in vivo, and compare them to human hepatoma cells (Huh7). AgNPs are incorporated in zebrafish liver cells (ZFL) and Huh7, and in zebrafish embryos. In ZFL cells AgNPs lead to induction of reactive oxygen species (ROS), endoplasmatic reticulum (ER) stress response, and TNF-α. Transcriptional alterations also occur in pro-apoptotic genes p53 and Bax. The transcriptional profile differed in ZFL and Huh7 cells. In ZFL cells, the ER stress marker BiP is induced, concomitant with the ER stress marker ATF-6 and spliced XBP-1 after 6 h and 24 h exposure to 0.5 g/L and 0.05 g/L AgNPs, respectively. This indicates the induction of different pathways of the ER stress response. Moreover, AgNPs induce TNF-α. In zebrafish embryos exposed to 0.01, 0.1, 1 and 5 mg/L AgNPs hatching was affected and morphological defects occurred at high concentrations. ER stress related gene transcripts BiP and Synv are significantly up-regulated after 24 h at 0.1 and 5 mg/L AgNPs. Furthermore, transcriptional alterations occurred in the pro-apoptotic genes Noxa and p21. The ER stress response was strong in ZFL cells and occurred in zebrafish embryos as well. Our data demonstrate for the first time that AgNPs lead to induction of ER stress in zebrafish. The induction of ER stress can have several consequences including the activation of apoptotic and inflammatory pathways. - Highlights: • Effects of silver nanoparticles (120 nm AgNPs) are investigated in zebrafish. • AgNPs induce all ER stress reponses in vitro in zebrafish liver cells. • AgNPs induce weak ER stress in zebrafish embryos. • AgNPs induce oxidative stress and transcripts of pro-apoptosis genes

  5. Investigations of nano-particle toxicity and uptake of Cerium oxide and Titanium dioxide in Arabidopsis thaliana (L.)

    Science.gov (United States)

    The emergence of nanotechnology and incorporation of nanoparticles in consumer products necessitates risk assessment from an environmental and health safety standpoint. To date, very few studies have examined nanoparticle effects on terrestrial species, especially plants. In ...

  6. A review on radiation-induced nucleation and growth of colloidal metallic nanoparticles

    OpenAIRE

    Abedini, Alam; Daud, Abdul Razak; Abdul Hamid, Muhammad Azmi; Kamil Othman, Norinsan; Saion, Elias

    2013-01-01

    This review presents an introduction to the synthesis of metallic nanoparticles by radiation-induced method, especially gamma irradiation. This method offers some benefits over the conventional methods because it provides fully reduced and highly pure nanoparticles free from by-products or chemical reducing agents, and is capable of controlling the particle size and structure. The nucleation and growth mechanism of metallic nanoparticles are also discussed. The competition between nucleation ...

  7. Elevated carbon dioxide reduces emission of herbivore-induced volatiles in Zea mays.

    Science.gov (United States)

    Block, Anna; Vaughan, Martha M; Christensen, Shawn A; Alborn, Hans T; Tumlinson, James H

    2017-09-01

    Terpene volatiles produced by sweet corn (Zea mays) upon infestation with pests such as beet armyworm (Spodoptera exigua) function as part of an indirect defence mechanism by attracting parasitoid wasps; yet little is known about the impact of climate change on this form of plant defence. To investigate how a central component of climate change affects indirect defence, we measured herbivore-induced volatile emissions in plants grown under elevated carbon dioxide (CO 2 ). We found that S. exigua infested or elicitor-treated Z. mays grown at elevated CO 2 had decreased emission of its major sesquiterpene, (E)-β-caryophyllene and two homoterpenes, (3E)-4,8-dimethyl-1,3,7-nonatriene and (3E,7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene. In contrast, inside the leaves, elicitor-induced (E)-β-caryophyllene hyper-accumulated at elevated CO 2 , while levels of homoterpenes were unaffected. Furthermore, gene expression analysis revealed that the induction of terpene synthase genes following treatment was lower in plants grown at elevated CO 2 . Our data indicate that elevated CO 2 leads both to a repression of volatile synthesis at the transcriptional level and to limitation of volatile release through effects of CO 2 on stomatal conductance. These findings suggest that elevated CO 2 may alter the ability of Z. mays to utilize volatile terpenes to mediate indirect defenses. © 2017 John Wiley & Sons Ltd.

  8. Examining the efficiency of muffle furnance-induced alkaline hydrolysis in determining the titanium content of environmental samples containing engineered titanium dioxide particles

    Science.gov (United States)

    A novel muffle furnace (MF)-based potassium hydroxide (KOH) fusion digestion technique was developed and its comparative digestion and dissolution efficacy for different titanium dioxide nanoparticles (TiO2-NPs)/environmental matrices was evaluated. Digestion of different enviro...

  9. Uniform deposition of ternary chalcogenide nanoparticles onto mesoporous TiO{sub 2} film using liquid carbon dioxide-based coating

    Energy Technology Data Exchange (ETDEWEB)

    Nursanto, Eduardus Budi [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Park, Se Jin [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Jeon, Hyo Sang; Hwang, Yun Jeong [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Kim, Jaehoon, E-mail: jaehoonkim@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, 2066, Seobu-Ro, Jangan-Gu, Suwon, GyeongGi-Do 440–746 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), 2066, Seobu-Ro, Jangan-Gu, Suwon, GyeongGi-Do 440–746 (Korea, Republic of); Min, Byoung Koun, E-mail: bkmin@kist.re.kr [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Green School, Korea University, 145,Anam-ro, Seongbuk-gu, Seoul 136–713 (Korea, Republic of)

    2014-08-28

    We report the simultaneous deposition of two different metal precursors dissolved in liquid carbon dioxide (l-CO{sub 2}), aiming to the synthesis of ternary chalcopyrite (e.g. CuInS{sub 2}) nanoparticles on a mesoporous TiO{sub 2} film. The l-CO{sub 2}-based deposition of Cu and In precursors and subsequent reaction with a dilute H{sub 2}S gas resulted in Cu{sub x}In{sub y}S{sub z} nanoparticles uniformly deposited across the entire thickness of a mesoporous TiO{sub 2} film. Further heat treatment (air annealing and sulfurization) led to the formation of more stoichiometric CuInS{sub 2} nanoparticles. The formation of CuInS{sub 2} on TiO{sub 2} was confirmed by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The crystal growth of CuInS{sub 2} was also found to be controllable by adjusting the number of coating cycles of the l-CO{sub 2}-based deposition. - Highlights: • Simultaneous deposition of two different metal precursors dissolved in l-CO{sub 2}. • Uniform deposition of CuInS{sub 2} nanoparticles across mesoporous TiO{sub 2} film. • Highly crystalline CuInS{sub 2} formed on mesoporous TiO{sub 2} film. • Nearly stoichiometric ratio of Cu:In:S was obtained.

  10. Ultrasensitive detection of target analyte-induced aggregation of gold nanoparticles using laser-induced nanoparticle Rayleigh scattering.

    Science.gov (United States)

    Lin, Jia-Hui; Tseng, Wei-Lung

    2015-01-01

    Detection of salt- and analyte-induced aggregation of gold nanoparticles (AuNPs) mostly relies on costly and bulky analytical instruments. To response this drawback, a portable, miniaturized, sensitive, and cost-effective detection technique is urgently required for rapid field detection and monitoring of target analyte via the use of AuNP-based sensor. This study combined a miniaturized spectrometer with a 532-nm laser to develop a laser-induced Rayleigh scattering technique, allowing the sensitive and selective detection of Rayleigh scattering from the aggregated AuNPs. Three AuNP-based sensing systems, including salt-, thiol- and metal ion-induced aggregation of the AuNPs, were performed to examine the sensitivity of laser-induced Rayleigh scattering technique. Salt-, thiol-, and metal ion-promoted NP aggregation were exemplified by the use of aptamer-adsorbed, fluorosurfactant-stabilized, and gallic acid-capped AuNPs for probing K(+), S-adenosylhomocysteine hydrolase-induced hydrolysis of S-adenosylhomocysteine, and Pb(2+), in sequence. Compared to the reported methods for monitoring the aggregated AuNPs, the proposed system provided distinct advantages of sensitivity. Laser-induced Rayleigh scattering technique was improved to be convenient, cheap, and portable by replacing a diode laser and a miniaturized spectrometer with a laser pointer and a smart-phone. Using this smart-phone-based detection platform, we can determine whether or not the Pb(2+) concentration exceed the maximum allowable level of Pb(2+) in drinking water. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Titanium dioxide nanoparticles enhance production of superoxide anion and alter the antioxidant system in human osteoblast cells

    Directory of Open Access Journals (Sweden)

    Niska K

    2015-02-01

    Full Text Available Karolina Niska,1 Katarzyna Pyszka,1 Cecylia Tukaj,2 Michal Wozniak,1 Marek Witold Radomski,3–5 Iwona Inkielewicz-Stepniak1 1Department of Medical Chemistry, 2Department of Electron Microscopy, Medical University of Gdansk, Gdansk, Poland; 3School of Pharmacy and Pharmaceutical Sciences, Trinity Biomedical Sciences Institute, The University of Dublin Trinity College, Dublin, Ireland; 4Kardio-Med Silesia, 5Silesian Medical University, Zabrze, Poland Abstract: Titanium dioxide (TiO2 nanoparticles (NPs are manufactured worldwide for a variety of engineering and bioengineering applications. TiO2NPs are frequently used as a material for orthopedic implants. However, to the best of our knowledge, the biocompatibility of TiO2NPs and their effects on osteoblast cells, which are responsible for the growth and remodeling of the human skeleton, have not been thoroughly investigated. In the research reported here, we studied the effects of exposing hFOB 1.19 human osteoblast cells to TiO2NPs (5–15 nm for 24 and 48 hours. Cell viability, alkaline phosphatase (ALP activity, cellular uptake of NPs, cell morphology, superoxide anion (O2•- generation, superoxide dismutase (SOD activity and protein level, sirtuin 3 (SIR3 protein level, correlation between manganese (Mn SOD and SIR, total antioxidant capacity, and malondialdehyde were measured following exposure of hFOB 1.19 cells to TiO2NPs. Exposure of hFOB 1.19 cells to TiO2NPs resulted in: (1 cellular uptake of NPs; (2 increased cytotoxicity and cell death in a time- and concentration-dependent manner; (3 ultrastructure changes; (4 decreased SOD and ALP activity; (5 decreased protein levels of SOD1, SOD2, and SIR3; (6 decreased total antioxidant capacity; (7 increased O2•- generation; and (8 enhanced lipid peroxidation (malondialdehyde level. The linear relationship between the protein level of MnSOD and SIR3 and between O2•- content and SIR3 protein level was observed. Importantly, the cytotoxic

  12. Efficacy of larvicidal activity of green synthesized titanium dioxide nanoparticles using Mangifera indica extract against blood-feeding parasites.

    Science.gov (United States)

    Rajakumar, Govindasamy; Rahuman, Abdul Abdul; Roopan, Selvaraj Mohana; Chung, Ill-Min; Anbarasan, Karunanithi; Karthikeyan, Viswanathan

    2015-02-01

    Titanium dioxide nanoparticles (TiO2 NPs) are considered to be among the best photocatalytic materials due to their long-term thermodynamic stability, strong oxidizing power, and relative non-toxicity. Nano-preparations with TiO2 NPs are currently under investigation as novel treatments for acne vulgaris, recurrent condyloma acuminata, atopic dermatitis, hyperpigmented skin lesions, and other non-dermatologic diseases. The present study was to investigate the acaricidal and larvicidal activity of synthesized TiO2 NPs utilizing leaf aqueous extract of Mangifera indica L. (Anacardiaceae) against hematophagous parasites. The anti-parasitic activity of TiO2 NPs against the larvae of Rhipicephalus (Boophilus) microplus, Hyalomma anatolicum anatolicum and Haemaphysalis bispinosa (Acari: Ixodidae), fourth instar larvae of Anopheles subpictus, and Culex quinquefasciatus (Diptera: Culicidae) were assessed. The green synthesized TiO2 NPs were analyzed by UV-Vis, FTIR, X-ray diffraction (XRD), AFM, SEM, and TEM. The XRD analysis of synthesized TiO2 NPs revealed the dominant peak at 2θ value of 27.81 which matched the 110 crystallographic plane of the rutile structure indicating the crystal structure. The FTIR spectra exhibited a prominent peak at 3,448 cm(-1) and showed OH stretching due to the alcoholic group, and the OH group may act as a capping agent. The SEM images of TiO2 NPs displayed spherical, oval in shape, individual, and some in aggregates. Characterization of the synthesized TiO2 NPs using AFM offered three-dimensional visualization and uneven surface morphology. The TEM micrograph showed agglomerates, round and slight elongation with an average size of 30 ± 5 nm. The maximum efficacy was observed in synthesized TiO2 NPs against the larvae of R. microplus, Hyalomma anatolicum anatolicum, Haemaphysalis bispinosa, A. subpictus, and Culex quinquefasciatus with LC50 value of 28.56, 33.17, 23.81, 5.84, and 4.34 mg/L, respectively. In the present study, a novel

  13. Titanium dioxide nanoparticles enhance production of superoxide anion and alter the antioxidant system in human osteoblast cells

    Science.gov (United States)

    Niska, Karolina; Pyszka, Katarzyna; Tukaj, Cecylia; Wozniak, Michal; Radomski, Marek Witold; Inkielewicz-Stepniak, Iwona

    2015-01-01

    Titanium dioxide (TiO2) nanoparticles (NPs) are manufactured worldwide for a variety of engineering and bioengineering applications. TiO2NPs are frequently used as a material for orthopedic implants. However, to the best of our knowledge, the biocompatibility of TiO2NPs and their effects on osteoblast cells, which are responsible for the growth and remodeling of the human skeleton, have not been thoroughly investigated. In the research reported here, we studied the effects of exposing hFOB 1.19 human osteoblast cells to TiO2NPs (5–15 nm) for 24 and 48 hours. Cell viability, alkaline phosphatase (ALP) activity, cellular uptake of NPs, cell morphology, superoxide anion (O2•−2) generation, superoxide dismutase (SOD) activity and protein level, sirtuin 3 (SIR3) protein level, correlation between manganese (Mn) SOD and SIR, total antioxidant capacity, and malondialdehyde were measured following exposure of hFOB 1.19 cells to TiO2NPs. Exposure of hFOB 1.19 cells to TiO2NPs resulted in: (1) cellular uptake of NPs; (2) increased cytotoxicity and cell death in a time- and concentration-dependent manner; (3) ultrastructure changes; (4) decreased SOD and ALP activity; (5) decreased protein levels of SOD1, SOD2, and SIR3; (6) decreased total antioxidant capacity; (7) increased O2•− generation; and (8) enhanced lipid peroxidation (malondialdehyde level). The linear relationship between the protein level of MnSOD and SIR3 and between O2•− content and SIR3 protein level was observed. Importantly, the cytotoxic effects of TiO2NPs were attenuated by the pretreatment of hFOB 1.19 cells with SOD, indicating the significant role of O2•− in the cell damage and death observed. Thus, decreased expression of SOD leading to increased oxidizing stress may underlie the nanotoxic effects of TiO2NPs on human osteoblasts. PMID:25709434

  14. Determination of Histamine in Silages Using Nanomaghemite Core (γ-Fe2O3-Titanium Dioxide Shell Nanoparticles Off-Line Coupled with Ion Exchange Chromatography

    Directory of Open Access Journals (Sweden)

    Natalia Cernei

    2016-09-01

    Full Text Available The presence of biogenic amines is a hallmark of degraded food and its products. Herein, we focused on the utilization of magnetic nanoparticles off-line coupled with ion exchange chromatography with post-column ninhydrin derivatization and Vis detection for histamine (Him separation and detection. Primarily, we described the synthesis of magnetic nanoparticles with nanomaghemite core (γ-Fe2O3 functionalized with titanium dioxide and, then, applied these particles to specific isolation of Him. To obtain further insight into interactions between paramagnetic particles’ (PMP surface and Him, a scanning electron microscope was employed. It was shown that binding of histamine causes an increase of relative current response of deprotonated PMPs, which confirmed formation of Him-PMPs clusters. The recovery of the isolation showed that titanium dioxide-based particles were able to bind and preconcentrate Him with recovery exceeding 90%. Finally, we successfully carried out the analyses of real samples obtained from silage. We can conclude that our modified particles are suitable for Him isolation, and thus may serve as the first isolation step of Him from biological samples, as it is demonstrated on alfalfa seed variety Tereza silage.

  15. Radiation Induced Formation of Acrylated Palm Oil Nanoparticles using Cetyltrimethylammonium Bromide Microemulsion System

    International Nuclear Information System (INIS)

    Rida Tajau; Rida Tajau; Wan Mohd Zin Wan Yunus

    2011-01-01

    In this study, we report the preparation of Acrylated Palm Oil (APO) nanoparticles using aqueous Cetyltrimethylammonium bromide (CTAB) microemulsion system. This microemulsion system which contains the dispersed APO nano droplets was subjected to the gamma irradiation to induce the formation of the crosslinked APO nanoparticle. After irradiation at higher doses, the size of APO nanoparticles was transformed from a submicron-sized to a nano-sized of the particles. Size decreasing might be due to the intermolecular and the intramolecular crosslinking reactions of the APO nanoparticles during the irradiation process. (author)

  16. Synthesis, characterization, and photocatalytic activities of Cobalt(II)-Titanium dioxide nanorods, and electrophoretic deposition of Titanium dioxide nanoparticle/nanorod composite films for self-cleaning applications

    Science.gov (United States)

    Kang, Wonjun

    This dissertation consists of two projects. The first project is synthesis, characterization, and photocatalytic activities of Co(II)-TiO2 nanorods. We modified brookite TiO2 nanorods with cobalt(II) ions to design new photocatalysts with visible light absorption. X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) data indicated that the local structure of Co(II)-TiO2 nanorods was shown as tetrahedral and octahedral Co(II) sites at TiO2 nanorod surface. Dimethylglyoxime (DMG) has been used to remove surface Co(II) from Co(II)-TiO2 nanorods to determine single-site Co(II) ions selectively attached to the TiO 2 nanorod surface. We proposed a mechanism that the Co-Co bond of the precursor Co2(CO)8 undergoes heterolysis followed by disproportionation of Co(I) to produce Co(II) and Co(0) precipitate. Finally, the Co(II)-TiO2 nanorods showed greater activity than TiO 2 nanorods in the degradation of 5,8-dihydroxy-1,4-naphthoquinone (DHNQ) dye under visible light irradiation. The second project is electrophoretic deposition (EPD) of TiO2 nanoparticle/nanorod composite films for self-cleaning applications. We developed novel electrolyte system for EPD of TiO2 nanoparticle/nanorod composites for self-cleaning coatings. A mixture of TiO2 powder and TiO2 nanorods was used as EPD suspension in a mixture of THF and acetone. TiO2 nanoparticle/nanorod composite films were fabricated on aluminium substrates via the EPD method, and were characterized by scanning electron microscope (SEM). SEM images showed that TiO2 nanoparticle/nanorod composite films had a uniform pore structure. The hydrophobic properties of surfaces in TiO2 nanoparticle/nanorod composite films were evaluated by water contact angle measurements. It was found that the surfaces of TiO2 nanoparticle/nanorod composite films were hydrophobic with contact angle of 103°. These hydrophobic surfaces are expected to have potential applications for self-cleaning.

  17. Green-synthetized silver nanoparticles for Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy (NELIBS) using a mobile instrument

    Science.gov (United States)

    Poggialini, F.; Campanella, B.; Giannarelli, S.; Grifoni, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Safi, A.; Palleschi, V.

    2018-03-01

    When compared to other analytical techniques, LIBS shows relatively low precision and, generally, high Limits of Detection (LODs). Until recently, the attempts in improving the LIBS performances have been based on the use of more stable/powerful lasers, high sensitivity detectors or controlled environmental parameters. This can hinder the competitiveness of LIBS by increasing the instrumental setup cost and the difficulty of operation. Sample treatment has proved to be a viable and simple way to increase the LIBS signal; in particular, the Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy (NELIBS) methodology uses a deposition of metal nanoparticles on the sample to greatly increase the emission of the LIBS plasma. In this work, we used a simple, fast, "green" and low-cost method to synthetize silver nanoparticles by using coffee extract as reducing agents for a silver nitrate solution. This allowed us to obtain nanoparticles of about 25 nm in diameter. We then explored the application of such nanoparticles to the NELIBS analysis of metallic samples with a mobile LIBS instrument. By adjusting the laser parameters and optimizing the sample preparation procedure, we obtained a NELIBS signal that is 4 times the LIBS one. This showed the potential of green-synthetized nanoparticle for NELIBS applications and suggests the possibility of an in-situ application of the technique.

  18. Radiolysis and sputtering of carbon dioxide ice induced by swift Ti, Ni, and Xe ions

    Energy Technology Data Exchange (ETDEWEB)

    Mejía, C. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente 225, 22453-900 Rio de Janeiro, RJ (Brazil); Bender, M.; Severin, D. [Materials Research Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Trautmann, C. [Materials Research Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technische Universität, 64287 Darmstadt (Germany); Boduch, Ph. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); Bordalo, V. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); Observatório Nacional-MCTI, Rua General José Cristino 77, 20921-400 Rio de Janeiro, RJ (Brazil); Domaracka, A.; Lv, X.Y. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); and others

    2015-12-15

    Solid carbon dioxide (CO{sub 2}) is found in several bodies of the solar system, the interstellar medium (ISM) and young stellar objects, where it is exposed to cosmic and stellar wind radiation. Here, the chemical and physical modifications induced by heavy ion irradiation of pure solid CO{sub 2} at low temperature (T = 15–30 K) are analyzed. The experiments were performed with Ti (550 MeV) and Xe (630 MeV) ions at the UNILAC of GSI/Darmstadt and with Ni ions (46 and 52 MeV) at IRRSUD of GANIL/Caen. The evolution of the thin CO{sub 2} ice films (deposited on a CsI window) was monitored by mid-infrared absorption spectroscopy (FTIR). The dissociation rate of CO{sub 2}, determined from the fluence dependence of the IR absorption peak intensity, is found to be proportional to the electronic stopping power S{sub e}. We also confirm that the sputtering yield shows a quadric increase with electronic stopping power. Furthermore, the production rates of daughter molecules such as CO, CO{sub 3} and O{sub 3} were found to be linear in S{sub e}.

  19. Counter flow induced draft cooling tower option for supercritical carbon dioxide Brayton cycle

    Energy Technology Data Exchange (ETDEWEB)

    Pidaparti, Sandeep R., E-mail: sandeep.pidaparti@gmail.com [Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, Atlanta, GA 30332 (United States); Moisseytsev, Anton; Sienicki, James J. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Ranjan, Devesh, E-mail: devesh.ranjan@me.gatech.edu [Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, Atlanta, GA 30332 (United States)

    2015-12-15

    Highlights: • A code was developed to investigate the various aspects of using cooling tower for S-CO{sub 2} Brayton cycles. • Cooling tower option to reject heat is quantitatively compared to the direct water cooling and dry air cooling options. • Optimum water conditions resulting in minimal plant capital cost per unit power consumption are calculated. - Abstract: A simplified qualitative analysis was performed to investigate the possibility of using counter flow induced draft cooling tower option to reject heat from the supercritical carbon dioxide Brayton cycle for advanced fast reactor (AFR)-100 and advanced burner reactor (ABR)-1000 plants. A code was developed to estimate the tower dimensions, power and water consumption, and to perform economic analysis. The code developed was verified against a vendor provided quotation and is used to understand the effect of ambient air and water conditions on the design of cooling tower. The calculations indicated that there exists optimum water conditions for given ambient air conditions which will result in minimum power consumption, thereby increasing the cycle efficiency. A cost-based optimization technique is used to estimate the optimum water conditions which will improve the overall plant economics. A comparison of different cooling options for the S-CO{sub 2} cycle indicated that the cooling tower option is a much more practical and economical option compared to the dry air cooling or direct water cooling options.

  20. Genotoxicity, potential cytotoxicity and cell uptake of titanium dioxide nanoparticles in the marine fish Trachinotus carolinus (Linnaeus, 1766)

    Energy Technology Data Exchange (ETDEWEB)

    Vignardi, Caroline P., E-mail: carolpatvig@usp.br [Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, Praça do Oceanogáfico 191, Cidade Universitária, Butantã, São Paulo, SP 05508900 (Brazil); Hasue, Fabio M., E-mail: humbigutis@gmail.com [Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, Praça do Oceanogáfico 191, Cidade Universitária, Butantã, São Paulo, SP 05508900 (Brazil); Sartório, Priscila V., E-mail: pri.sartorio@gmail.com [Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, Praça do Oceanogáfico 191, Cidade Universitária, Butantã, São Paulo, SP 05508900 (Brazil); Cardoso, Caroline M., E-mail: camargonato@gmail.com [Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, Praça do Oceanogáfico 191, Cidade Universitária, Butantã, São Paulo, SP 05508900 (Brazil); Machado, Alex S.D., E-mail: mamiferomarinho@gmail.com [Faculty of Veterinary Medicine, Integrated College North of Minas Osmane Barbosa Avenue, 11111, JK, Montes Claros, MG 39404006 (Brazil); and others

    2015-01-15

    Highlights: • TiO{sub 2}–NP cytogenotoxicity and cell uptake in marine fish was studied. • TiO{sub 2}–NP suspension was in primary particle, agglomerated and aggregated form. • TiO{sub 2}–NP genotoxicity was time/dose dependent and may induce cell uptake. • Methodology proved to be efficient for evaluating the toxic effect of TiO{sub 2}–NP. - Abstract: Nanoparticles have physicochemical characteristics that make them useful in areas such as science, technology, medicine and in products of everyday use. Recently the manufacture and variety of these products has grown rapidly, raising concerns about their impact on human health and the environment. Adverse effects of exposure to nanoparticles have been reported for both terrestrial and aquatic organisms, but the toxic effects of the substances on marine organisms remain poorly understood. The main aim of this study was to evaluate the genotoxicity of TiO{sub 2}–NP in the marine fish Trachinotus carolinus, through cytogenotoxic methods. The fish received two different doses of 1.5 μg and 3.0 μg–TiO{sub 2}–NP g{sup −1} by intraperitoneal injection. Blood samples were collected to analyze erythrocyte viability using the Trypan Blue exclusion test, comet assay (pH > 13), micronucleus (MN) and other erythrocyte nuclear abnormalities (ENA) 24, 48 and 72 h after injection. The possible cell uptake of TiO{sub 2}–NP in fish injected with the higher dose was investigated after 72 h using transmission electron microscopy (TEM). The results showed that TiO{sub 2}–NP is genotoxic and potentially cytotoxic for this species, causing DNA damage, inducing the formation of MN and other ENA, and decreasing erythrocyte viability. TEM examination revealed that cell uptake of TiO{sub 2}–NP was mainly in the kidney, liver, gills and to a lesser degree in muscle. To the extent of the authors’ knowledge, this is the first in vivo study of genotoxicity and other effects of TiO{sub 2}–NP in a marine fish.

  1. Plasmon transmutation: inducing new modes in nanoclusters by adding dielectric nanoparticles.

    Science.gov (United States)

    Wen, Fangfang; Ye, Jian; Liu, Na; Van Dorpe, Pol; Nordlander, Peter; Halas, Naomi J

    2012-09-12

    Planar clusters of coupled plasmonic nanoparticles support nanoscale electromagnetic "hot spots" and coherent effects, such as Fano resonances, with unique near and far field signatures, currently of prime interest for sensing applications. Here we show that plasmonic cluster properties can be substantially modified by the addition of individual, discrete dielectric nanoparticles at specific locations on the cluster, introducing new plasmon modes, or transmuting existing plasmon modes to new ones, in the resulting metallodielectric nanocomplex. Depositing a single carbon nanoparticle in the junction between a pair of adjacent nanodisks induces a metal-dielectric-metal quadrupolar plasmon mode. In a ten-membered cluster, placement of several carbon nanoparticles in junctions between multiple adjacent nanoparticles introduces a collective magnetic plasmon mode into the Fano dip, giving rise to an additional subradiant mode in the metallodielectric nanocluster response. These examples illustrate that adding dielectric nanoparticles to metallic nanoclusters expands the number and types of plasmon modes supported by these new mixed-media nanoscale assemblies.

  2. Synthesis of Photocrosslinkable and Amine Containing Multifunctional Nanoparticles via Polymerization-Induced Self-Assembly.

    Science.gov (United States)

    Huang, Jianbing; Li, Decai; Liang, Hui; Lu, Jiang

    2017-08-01

    Photo-crosslinkable and amine-containing block copolymer nanoparticles are synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization-induced self-assembly of a multifunctional core-forming monomer, 2-((3-(4-(diethylamino)phenyl)acryloyl)oxy)ethyl methacrylate (DEMA), using poly(2-hydroxypropyl methacrylate) macromolecular chain transfer agent as a steric stabilizer in methanol at 65 °C. By tuning the chain length of PDEMA, a range of nanoparticle morphologies (sphere, worm, and vesicle) can be obtained. Since cinnamate groups can easily undergo a [2 + 2] cycloaddition of the carbon-carbon double bonds upon UV irradiation, the as-prepared block copolymer nanoparticles are readily stabilized by photo-crosslinking to produce anisotropic nanoparticles. The crosslinked block copolymer nanoparticles can be used as templates for in situ formation polymer/gold hybrid nanoparticles. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Strong Antibody Responses Induced by Protein Antigens Conjugated onto the Surface of Lecithin-Based Nanoparticles

    Science.gov (United States)

    Sloat, Brian R.; Sandoval, Michael A.; Hau, Andrew M.; He, Yongqun; Cui, Zhengrong

    2009-01-01

    An accumulation of research over the years has demonstrated the utility of nanoparticles as antigen carriers with adjuvant activity. Herein we defined the adjuvanticity of a novel lecithin-based nanoparticle engineered from emulsions. The nanoparticles were spheres of around 200 nm. Model protein antigens, bovine serum albumin (BSA) or Bacillus anthracis protective antigen (PA) protein, were covalently conjugated onto the nanoparticles. Mice immunized with the BSA-conjugated nanoparticles developed strong anti-BSA antibody responses comparable to that induced by BSA adjuvanted with incomplete Freund's adjuvant and 6.5-fold stronger than that induced by BSA adsorbed onto aluminum hydroxide. Immunization of mice with the PA-conjugated nanoparticles elicited a quick, strong, and durable anti-PA antibody response that afforded protection of the mice against a lethal dose of anthrax lethal toxin challenge. The potent adjuvanticity of the nanoparticles was likely due to their ability to move the antigens into local draining lymph nodes, to enhance the uptake of the antigens by antigen-presenting cells (APCs), and to activate APCs. This novel nanoparticle system has the potential to serve as a universal protein-based vaccine carrier capable of inducing strong immune responses. PMID:19729045

  4. Visible laser induced positive ion emissions from NaCl nanoparticles prepared by droplet rapid drying

    International Nuclear Information System (INIS)

    Sun, Mao-Xu; Guo, Deng-Zhu; Xing, Ying-Jie; Zhang, Geng-Min

    2012-01-01

    Highlights: ► NaCl nanoparticles were firstly prepared by heat induced explosion on silicon wafer. ► We found that laser induced ion emissions from NaCl nanoparticles are more prominent. ► We found that water adsorption can efficiently enhance laser induced ion emissions. ► The ultra-photothermal effect in NaCl nanoparticles was observed and explained. - Abstract: A novel convenient way for the formation of sodium chloride (NaCl) nanoparticles on silicon wafer is proposed by using a droplet rapid drying method. The laser induced positive ion emissions from NaCl nanoparticles with and without water treatment is demonstrated by using a laser desorption/ionization time-of-flight mass spectrometer, with laser intensity well below the plasma formation threshold. It is found that the positive ion emissions from NaCl nanoparticles are obviously higher than that from microsize NaCl particles under soft 532 nm laser irradiations, and water adsorption can efficiently enhance the ion emissions from NaCl nanoparticles. The initial kinetic energies of the emitted ions are estimated as 16–17 eV. The synergy of the ultra-thermal effect in nanomaterials, the defect-mediated multiphoton processes, and the existence of intermediate states in NaCl-water interfaces are suggested as the mechanisms.

  5. Laser-Induced, Local Oxidation of Copper Nanoparticle Films During Raman Measurements

    Science.gov (United States)

    Hight Walker, Angela R.; Cheng, Guangjun; Calizo, Irene

    2011-03-01

    The optical properties of gold and silver nanoparticles and their films have been thoroughly investigated as surface enhanced Raman scattering (SERS) substrates and chemical reaction promoters. Similar to gold and silver nanoparticles, copper nanoparticles exhibit distinct plasmon absorptions in the visible region. The work on copper nanoparticles and their films is limited due to their oxidization in air. However, their high reactivity actually provides an opportunity to exploit the laser-induced thermal effect and chemical reactions of these nanoparticles. Here, we present our investigation of the local oxidation of a copper nanoparticle film induced by a visible laser source during Raman spectroscopic measurements. The copper nanoparticle film is prepared by drop-casting chemically synthesized copper colloid onto silicon oxide/silicon substrate. The local oxidation induced by visible lasers in Raman spectroscopy is monitored with the distinct scattering peaks for copper oxides. Optical microscopy and scanning electron microscopy have been used to characterize the laser-induced morphological changes in the film. The results of this oxidation process with different excitation wavelengths and different laser powers will be presented.

  6. Effects of carbon dioxide therapy on the healing of acute skin wounds induced on the back of rats

    Directory of Open Access Journals (Sweden)

    Maria Vitória Carmo Penhavel

    2013-05-01

    Full Text Available PURPOSE: To evaluate the healing effect of carbon dioxide therapy on skin wounds induced on the back of rats. METHODS: Sixteen rats underwent excision of a round dermal-epidermal dorsal skin flap of 2.5 cm in diameter. The animals were divided into two groups, as follows: carbon dioxide group - subcutaneous injections of carbon dioxide on the day of operation and at three, six and nine days postoperatively; control group - no postoperative wound treatment. Wounds were photographed on the day of operation and at six and 14 days postoperatively for analysis of wound area and major diameter. All animals were euthanized on day 14 after surgery. The dorsal skin and the underlying muscle layer containing the wound were resected for histopathological analysis. RESULTS: There was no statistically significant difference between groups in the percentage of wound closure, in histopathological findings, or in the reduction of wound area and major diameter at 14 days postoperatively. CONCLUSION: Under the experimental conditions in which this study was conducted, carbon dioxide therapy had no effects on the healing of acute skin wounds in rats.

  7. Ruthenium dioxide nanoparticles in ionic liquids: synthesis, characterization and catalytic properties in hydrogenation of olefins and arenes

    International Nuclear Information System (INIS)

    Rossi, Liane M.; Dupont, Jairton; Machado, Giovanna; Fichtner, Paulo F.P.; Radtke, Claudio; Baumvol, Israel J.R.; Teixeira, Sergio R.

    2004-01-01

    The reaction of NaBH 4 with RuCl 3 dissolved in 1-n-butyl-3-methylimidazolium hexafluorophosphate (BMI.PF 6 ) ionic liquid is a simple and reproducible method for the synthesis of stable RuO 2 nanoparticles with a narrow size distribution within 2-3 nm. RuO 2 nanoparticles were characterized by XRD, XPS, EDS and TEM. These nanoparticles showed high catalytic activity either in the solventless or liquid-liquid biphasic hydrogenation of olefins and arenes under mild reaction conditions. Hg(0) and CS 2 poisoning experiments and XRD and TEM analysis of particles isolated after catalysis indicated the formation of Ru(0) nanoparticles. The nanoparticles could be re-used in solventless conditions up to 10 times in the hydrogenation of 1-hexene yielding a total turnover number for exposed Ru atoms of 175,000. (author)

  8. In vitro cell transformation induced by synthetic amorphous silica nanoparticles.

    Science.gov (United States)

    Fontana, Caroline; Kirsch, Anaïs; Seidel, Carole; Marpeaux, Léa; Darne, Christian; Gaté, Laurent; Remy, Aurélie; Guichard, Yves

    2017-11-01

    Synthetic amorphous silica nanoparticles (SAS) are among the most widely produced and used nanomaterials, but little is known about their carcinogenic potential. This study aims to evaluate the ability of four different SAS, two precipitated, NM-200 and NM-201, and two pyrogenic, NM-202 and NM-203, to induce the transformation process. For this, we used the recently developed in vitro Bhas 42 cell transformation assay (CTA). The genome of the transgenic Bhas 42 cells contains several copies of the v-Ha-ras gene, making them particularly sensitive to tumor-promoter agents. The Bhas 42 CTA, which includes an initiation assay and a promotion assay, was validated in our laboratory using known soluble carcinogenic substances. Its suitability for particle-type substances was verified by using quartz Min-U-Sil 5 (Min-U-Sil) and diatomaceous earth (DE) microparticles. As expected given their known transforming properties, Min-U-Sil responded positively in the Bhas 42 CTA and DE responded negatively. Transformation assays were performed with SAS at concentrations ranging from 2μg/cm 2 to 80μg/cm 2 . Results showed that all SAS have the capacity to induce transformed foci, interestingly only in the promotion assay, suggesting a mode of action similar to tumor-promoter substances. NM-203 exhibited transforming activity at a lower concentration than the other SAS. In conclusion, this study showed for the first time the transforming potential of different SAS, which act as tumor-promoter substances in the Bhas 42 model of cell transformation. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Co-exposure to titanium dioxide nanoparticles does not affect cadmium toxicity in radish seeds (Raphanus sativus).

    Science.gov (United States)

    Manesh, R Roshan; Grassi, G; Bergami, E; Marques-Santos, L F; Faleri, C; Liberatori, G; Corsi, I

    2018-02-01

    Recent developments on environmental fate models indicate that as nano waste, engineered nanomaterials (ENMs) could reach terrestrial ecosystems thus potentially affecting environmental and human health. Plants can be therefore exposed to ENMs but controversial data in terms of fate and toxicity are currently available. Furthermore, there is a current lack of information on complex interactions/transformations to which ENMs undergo in the natural environment as for instance interacting with existing toxic compounds. The aim of the present study was to assess the behavior and biological effects of titanium dioxide nanoparticles (n-TiO 2 ) (Aeroxide P25, Degussa Evonik) and its interaction with cadmium (CdCl 2 ) in plants using radish seeds (Raphanus sativus L. Parvus) as model species. Radish seeds were exposed to n-TiO 2 (1-1000mg/L) and CdCl 2 (1-250mg/L) alone and in combination using a seed germination and seedling growth toxicity test OECD 208. Percentage of seed germination, germination index (GI) and root elongation were calculated. Cell morphology and oxidative stress parameters as glutathione-S-transferase (GST) and catalase activities (CAT) were measured in radish seeds after 5 days of exposure. Z-Average, PdI and Z-potential of n-TiO 2 in Milli-Q water as exposure medium were also determined. DLS analysis showed small aggregates of n-TiO 2 , negative Z-potential and stable PdI in seed's exposure media. Germination percentage, GI and root length resulted affected by n-TiO 2 exposure compared to controls. In particular, n-TiO 2 at 1mg/L and 100mg/L did not affect radish seeds germination (100%) while at concentration of 10mg/L, 200mg/L, 500mg/L, and 1000mg/L a slight but not significant decrease of germination % was observed. Similarly root length and GI resulted significantly higher in seeds exposed to 10mg/L and 200mg/L compared to 1mg/L, 100mg/L, 500mg/L, 1000mg/L and control (p germination % and GI compared to control seeds and a concentration dependent

  10. Carbon dioxide sequestration induced mineral precipitation healing of fractured reservoir seals

    Science.gov (United States)

    Welch, N.; Crawshaw, J.

    2017-12-01

    Initial experiments and the thermodynaic basis for carbon dioxide sequestration induced mineral precipitation healing of fractures through reservoir seals will be presented. The basis of this work is the potential exists for the dissolution of reservoir host rock formation carbonate minerals in the acidified injection front of CO2 during sequestration or EOR. This enriched brine and the bulk CO2 phase will then flow through the reservoir until contact with the reservoir seal. At this point any fractures present in the reservoir seal will be the preferential flow path for the bulk CO2 phase as well as the acidified brine front. These fractures would currently be filled with non-acidified brine saturated in seal formation brine. When the acidifeid brine from the host formation and the cap rock brine mix there is the potential for minerals to fall out of solution, and for these precipitated minerals to decrease or entirely cut off the fluid flow through the fractures present in a reservoir seal. Initial equilibrium simulations performed using the PHREEQC1 database drived from the PHREEQE2 database are used to show the favorable conditions under which this mineral precipitation can occurs. Bench scale fluid mixing experiments were then performed to determine the kinetics of the mineral precipitation process, and determine the progress of future experiemnts involving fluid flow within fractured anhydrite reservoir seal samples. 1Parkhurst, D.L., and Appelo, C.A.J., 2013, Description of input and examples for PHREEQC version 3—A computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations: U.S. Geological Survey Techniques and Methods, book 6, chap. A43, 497 p., available only at https://pubs.usgs.gov/tm/06/a43/. 2Parkhurst, David L., Donald C. Thorstenson, and L. Niel Plummer. PHREEQE: a computer program for geochemical calculations. No. 80-96. US Geological Survey, Water Resources Division,, 1980.

  11. 3D characterization of coal strains induced by compression, carbon dioxide sorption, and desorption at in-situ stress conditions

    International Nuclear Information System (INIS)

    Pone, J. Denis N.; Halleck, Phillip M.; Mathews, Jonathan P.

    2010-01-01

    Sequestration of carbon dioxide in unmineable coal seams is an option to combat climate change and an opportunity to enhance coalbed methane production. Prediction of sequestration potential in coal requires characterization of porosity, permeability, sorption capacity and the magnitude of swelling due to carbon dioxide uptake or shrinkage due to methane and water loss. Unfortunately, the majority of data characterizing coal-gas systems have been obtained from powdered, unconfined coal samples. Little is known about confined coal behavior during carbon dioxide uptake and methane desorption. The present work focuses on the characterization of lithotype specific deformation, and strain behavior during CO 2 uptake at simulated in-situ stress conditions. It includes the evaluation of three-dimensional strain induced by the confining stress, the sorption, and the desorption of carbon dioxide. X-ray computed tomography allowed three-dimensional characterization of the bituminous coal deformation samples under hydrostatic stress. The application of 6.9 MPa of confining stress contributes an average of - 0.34% volumetric strain. Normal strains due to confining stress were - 0.08%, - 0.15% and - 0.11% along the x, y and z axes respectively. Gas injection pressure was 3.1 MPa and the excess sorption was 0.85 mmol/g. Confined coal exposed to CO 2 for 26 days displays an average volumetric expansion of 0.4%. Normal strains due to CO 2 sorption were 0.11%, 0.22% and 0.11% along x, y and z axes. Drainage of the CO 2 induced an average of - 0.33% volumetric shrinkage. Normal strains due to CO 2 desorption were - 0.23%, - 0.08% and - 0.02% along x, y and z axes. Alternating positive and negative strain values observed along the sample length during compression, sorption and desorption respectively emphasized that both localized compression/compaction and expansion of coal will occur during CO 2 sequestration. (author)

  12. Intratracheally instilled titanium dioxide nanoparticles translocate to heart and liver and activate complement cascade in the heart of C57BL/6 mice

    DEFF Research Database (Denmark)

    Husain, Mainul; Wu, Dongmei; Saber, Anne T.

    2015-01-01

    translocation from the lungs. Adult female C57BL/6 mice were exposed via intratracheal instillation to 18 or 162 mu g of industrially relevant titanium dioxide nanoparticles (nano-TiO2) alongside vehicle controls. Using the nano-scale hyperspectral microscope, translocation to heart and liver was confirmed...... of translocation are unclear. We employed a nano-scale hyperspectral microscope to spatially observe and spectrally profile NPs in tissues and blood following pulmonary deposition in mice. In addition, we characterized effects occurring in blood, liver and heart at the mRNA and protein level following...... at both doses, and to blood at the highest dose, in mice analyzed 24 h post-exposure. Global gene expression profiling and ELISA analysis revealed activation of complement cascade and inflammatory processes in heart and specific activation of complement factor 3 in blood, suggesting activation of an early...

  13. Controlling Foam Morphology of Poly(methyl methacrylate via Surface Chemistry and Concentration of Silica Nanoparticles and Supercritical Carbon Dioxide Process Parameters

    Directory of Open Access Journals (Sweden)

    Deniz Rende

    2013-01-01

    Full Text Available Polymer nanocomposite foams have received considerable attention because of their potential use in advanced applications such as bone scaffolds, food packaging, and transportation materials due to their low density and enhanced mechanical, thermal, and electrical properties compared to traditional polymer foams. In this study, silica nanofillers were used as nucleating agents and supercritical carbon dioxide as the foaming agent. The use of nanofillers provides an interface upon which CO2 nucleates and leads to remarkably low average cell sizes while improving cell density (number of cells per unit volume. In this study, the effect of concentration, the extent of surface modification of silica nanofillers with CO2-philic chemical groups, and supercritical carbon dioxide process conditions on the foam morphology of poly(methyl methacrylate, PMMA, were systematically investigated to shed light on the relative importance of material and process parameters. The silica nanoparticles were chemically modified with tridecafluoro-1,1,2,2-tetrahydrooctyl triethoxysilane leading to three different surface chemistries. The silica concentration was varied from 0.85 to 3.2% (by weight. The supercritical CO2 foaming was performed at four different temperatures (40, 65, 75, and 85°C and between 8.97 and 17.93 MPa. By altering the surface chemistry of the silica nanofiller and manipulating the process conditions, the average cell diameter was decreased from 9.62±5.22 to 1.06±0.32 μm, whereas, the cell density was increased from 7.5±0.5×108 to 4.8±0.3×1011 cells/cm3. Our findings indicate that surface modification of silica nanoparticles with CO2-philic surfactants has the strongest effect on foam morphology.

  14. Amorphous silica nanoparticles impair vascular homeostasis and induce systemic inflammation

    Directory of Open Access Journals (Sweden)

    Nemmar A

    2014-06-01

    Full Text Available Abderrahim Nemmar,1 Sulayma Albarwani,2 Sumaya Beegam,1 Priya Yuvaraju,1 Javed Yasin,3 Samir Attoub,4 Badreldin H Ali5 1Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates; 2Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University, Al-Khod, Sultanate of Oman; 3Department of Internal Medicine, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates; 4Department of Pharmacology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates; 5Department of Pharmacology, College of Medicine and Health Sciences, Sultan Qaboos University, Al-Khod, Sultanate of Oman Abstract: Amorphous silica nanoparticles (SiNPs are being used in biomedical, pharmaceutical, and many other industrial applications entailing human exposure. However, their potential vascular and systemic pathophysiologic effects are not fully understood. Here, we investigated the acute (24 hours systemic toxicity of intraperitoneally administered 50 nm and 500 nm SiNPs in mice (0.5 mg/kg. Both sizes of SiNPs induced a platelet proaggregatory effect in pial venules and increased plasma concentration of plasminogen activator inhibitor-1. Elevated plasma levels of von Willebrand factor and fibrinogen and a decrease in the number of circulating platelets were only seen following the administration of 50 nm SiNPs. The direct addition of SiNPs to untreated mouse blood significantly induced in vitro platelet aggregation in a dose-dependent fashion, and these effects were more pronounced with 50 nm SiNPs. Both sizes of SiNPs increased lactate dehydrogenase activity and interleukin 1β concentration. However, tumor necrosis factor α concentration was only increased after the administration of 50 nm SiNPs. Nevertheless, plasma markers of oxidative stress, including 8-isoprostane

  15. Molecular and physiological responses to titanium dioxide ...

    Science.gov (United States)

    - Changes in tissue transcriptomes and productivity of Arabidopsis thaliana were investigated during exposure of plants to two widely-used engineered metal oxide nanoparticles, titanium dioxide (nano-titanium) and cerium dioxide (nano-cerium). Microarray analyses confirmed that exposure to either nanoparticle altered the transcriptomes of rosette leaves and roots, with comparatively larger numbers of differentially expressed genes (DEGs) found under nano-titania exposure. Nano-titania induced more DEGs in rosette leaves, whereas roots had more DEGs under nano-ceria exposure. MapMan analyses indicated that while nano-titania up-regulated overall and secondary metabolism in both tissues, metabolic processes under nano-ceria remained mostly unchanged. Gene enrichment analysis indicated that both nanoparticles mainly enriched ontology groups such as responses to stress (abiotic and biotic), and defense responses (pathogens), and responses to endogenous stimuli (hormones). Nano-titania specifically induced genes associated with photosynthesis, whereas nano-ceria induced expression of genes related to activating transcription factors, most notably those belonging to the ethylene responsive element binding protein family. Interestingly, there were also increased numbers of rosette leaves and plant biomass under nano-ceria exposure, but not under nano-titania. Other transcriptomic responses did not clearly relate to responses observed at the organism level. This may b

  16. In vitro exposure of haemocytes of the clam Ruditapes philippinarum to titanium dioxide (TiO2) nanoparticles: nanoparticle characterisation, effects on phagocytic activity and internalisation of nanoparticles into haemocytes.

    Science.gov (United States)

    Marisa, Ilaria; Marin, Maria Gabriella; Caicci, Federico; Franceschinis, Erica; Martucci, Alessandro; Matozzo, Valerio

    2015-02-01

    The continuous growth of nanotechnology and nano-industries, the considerable increase of products containing nanoparticles (NPs) and the potential release of NPs in aquatic environments suggest a need to study NP effects on aquatic organisms. In this context, in vitro assays are commonly used for evaluating or predicting the negative effects of chemicals and for understanding their mechanisms of action. In this study, a physico-chemical characterisation of titanium dioxide NPs (n-TiO2) was performed, and an in vitro approach was used to investigate the effects of n-TiO2 on haemocytes of the clam Ruditapes philippinarum. In particular, the effects on haemocyte phagocytic activity were evaluated in two different experiments (with and without pre-treatment of haemocytes) by exposing cells to P25 n-TiO2 (0, 1 and 10 μg/mL). In addition, the capability of n-TiO2 to interact with clam haemocytes was evaluated with a transmission electron microscope (TEM). In this study, n-TiO2 particles showed a mean diameter of approximately 21 nm, and both anatase (70%) and rutile (30%) phases were revealed. In both experiments, n-TiO2 significantly decreased the phagocytic index compared with the control, suggesting that NPs are able to interfere with cell functions. The results of the TEM analysis support this hypothesis. Indeed, we observed that TiO2 NPs interact with cell membranes and enter haemocyte cytoplasm and vacuoles after 60 min of exposure. To the best of our knowledge, this is the first study demonstrating the internalisation of TiO2 NPs into R. philippinarum haemocytes. The present study can contribute to the understanding of the mechanisms of action of TiO2 NPs in bivalve molluscs, at least at the haemocyte level. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Fabrication of fluorescent silica nanoparticles with aggregation-induced emission luminogens for cell imaging.

    Science.gov (United States)

    Chen, Sijie; Lam, Jacky W Y; Tang, Ben Zhong

    2013-01-01

    Fluorescence-based techniques have found wide applications in life science. Among various luminogenic materials, fluorescent nanoparticles have attracted much attention due to their fabulous emission properties and potential applications as sensors. Here, we describe the fabrication of fluorescent silica nanoparticles (FSNPs) containing aggregation-induced emission (AIE) luminogens. By employing surfactant-free sol-gel reaction, FSNPs with uniform size and high surface charge and colloidal stability are generated. The FSNPs emit strong light upon photoexcitation, due to the AIE characteristic of the silole -aggregates in the hybrid nanoparticles. The FSNPs are cytocompatible and can be utilized as fluorescent visualizer for intracellular imaging for HeLa cells.

  18. Size and alloying induced shift in core and valence bands of Pd-Ag and Pd-Cu nanoparticles

    International Nuclear Information System (INIS)

    Sengar, Saurabh K.; Mehta, B. R.; Govind

    2014-01-01

    In this report, X-ray photoelectron spectroscopy studies have been carried out on Pd, Ag, Cu, Pd-Ag, and Pd-Cu nanoparticles having identical sizes corresponding to mobility equivalent diameters of 60, 40, and 20 nm. The nanoparticles were prepared by the gas phase synthesis method. The effect of size on valence and core levels in metal and alloy nanoparticles has been studied by comparing the values to those with the 60 nm nanoparticles. The effect of alloying has been investigated by comparing the valence and core level binding energies of Pd-Cu and Pd-Ag alloy nanoparticles with the corresponding values for Pd, Ag, and Cu nanoparticles of identical sizes. These effects have been explained in terms of size induced lattice contractions, alloying induced charge transfer, and hybridization effects. The observation of alloying and size induced binding energy shifts in bimetallic nanoparticles is important from the point of view of hydrogen reactivity

  19. Green Synthesis of Silver Nanoparticles Induced by the Fungus ...

    African Journals Online (AJOL)

    Ag) nanoparticles synthesized and stabilized using Penicillium citrinum isolated from soil. Methods: The pure colonies of Penicillium citrinum were cultured in Czapek dox broth. The supernatant of the broth was examined for the ability to ...

  20. Roughening of Pt nanoparticles induced by surface-oxide formation

    NARCIS (Netherlands)

    Zhu, T.; Hensen, E.J.M.; Santen, van R.A.; Tian, N.; Sun, S.-G.; Kaghazchi, P.; Jacob, T.

    2013-01-01

    Using density functional theory (DFT) and thermodynamic considerations we studied the equilibrium shape of Pt nanoparticles (NPs) under electrochemical conditions. We found that at very high oxygen coverage, obtained at high electrode potentials, the experimentally-observed tetrahexahedral (THH) NPs

  1. Heat-induced spinodal decomposition of Ag–Cu nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Sopoušek, J.; Zobač, O.; Buršík, Jiří; Roupcová, Pavla; Vykoukal, V.; Brož, P.; Pinkas, J.; Vřešťál, J.

    2015-01-01

    Roč. 17, č. 42 (2015), s. 28277-28285 ISSN 1463-9076 Institutional support: RVO:68081723 Keywords : nanoparticle synthesis * CALPHAD * XRD Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.449, year: 2015

  2. Tunable top-down fabrication and functional surface coating of single-crystal titanium dioxide nanostructures and nanoparticles

    NARCIS (Netherlands)

    Dekker, N.H.; Ha, S.; Janissen, R.; Ussembayev, Y.; van Oene, M.M.; Solano Hermosilla, B.P.

    2016-01-01

    Titanium dioxide (TiO2) is a key component of diverse optical and electronic applications that exploit its exceptional material properties. In particular, the use of TiO2 in its single-crystalline phase can offer substantial advantages over its amorphous and polycrystalline phases for existing and

  3. Germination and early plant development of ten plant species exposed to titanium dioxide and cerium oxide nanoparticles

    Science.gov (United States)

    Ten agronomic plant species were exposed to different concentrations of nano titanium dioxide (nTiO2) or nano cerium oxide (nCeO2) (0, 250, 500 and 1000 mg/L) to examine potential effects on germination and early seedling development. We modified a standard test protocol develop...

  4. Preparation of gold nanoparticle dimers via streptavidin-induced interlinking

    International Nuclear Information System (INIS)

    Zon, Vera B.; Sachsenhauser, Matthias; Rant, Ulrich

    2013-01-01

    There is great interest in establishing efficient means of organizing nanoparticles into complex structures, especially in fields like nano-optical devices. One of the demonstrated routes uses biomolecular scaffolds, like the streptavidin–biotin system, to deterministically separate and structure particle complexes. However, controlled formation of streptavidin-linked nanoparticle dimers or trimers is challenging, and large aggregates are often formed under conditions that are difficult to regulate. Here, we studied the aggregates and interlinking kinetics of biotin-functionalized 20 nm gold nanoparticles in the presence of the interlinking protein, streptavidin. We found two different protein-linker concentration regions where small stable particle aggregates are formed: when the protein and nanoparticle concentrations are similar and when the protein to nanoparticle concentration ratio exceeds intermediate concentrations (10:1–100:1) that promote precipitation of large aggregates. We attribute this behavior to the limited availability of free-linker molecules and the limited availability of free ligand (biotin) on the particle surface for low and high protein concentrations, respectively. Furthermore, we show that the product can be additionally enriched up to 25 % through either centrifugation in sucrose or size-exclusion chromatography. These results provide additional understanding into the assembly of ligand-functionalized nanoparticles with water-soluble linkers and provide a facile way to produce well-defined small aggregates for potential use in, for instance, surface-enhanced spectroscopy

  5. Attenuated effects of chitosan-capped gold nanoparticles on LPS-induced toxicity in laboratory rats

    International Nuclear Information System (INIS)

    Stefan, Marius; Melnig, Viorel; Pricop, Daniela; Neagu, Anca; Mihasan, Marius; Tartau, Liliana; Hritcu, Lucian

    2013-01-01

    The impact of nanoparticles in medicine and biology has increased rapidly in recent years. Gold nanoparticles (AuNP) have advantageous properties such as chemical stability, high electron density and affinity to biomolecules. However, the effects of AuNP on human body after repeated administration are still unclear. Therefore, the purpose of the present study was to evaluate the effects of gold-11.68 nm (AuNP1, 9.8 μg) and gold-22.22 nm (AuNP2, 19.7 μg) nanoparticles capped with chitosan on brain and liver tissue reactivity in male Wistar rats exposed to lipopolysaccharide (LPS from Escherichia coli serotype 0111:B4, 250 μg) upon 8 daily sessions of intraperitoneal administration. Our results suggest that the smaller size of chitosan-capped AuNP shows the protective effects against LPS-induced toxicity, suggesting a very high potential for biomedical applications. - Highlights: ► Smaller size of chitosan-capped gold nanoparticles acts against LPS-induced toxicity. ► Larger size of chitosan-capped gold nanoparticles agglomerated inside neurons and induced toxicity in combination with LPS. ► Chitosan has excellent biocompatible proprieties. ► Smaller size of chitosan-capped gold nanoparticles demonstrates great potential in biomedical applications.

  6. A mixture of anatase and rutile TiO2 nanoparticles induces histamine secretion in mast cells

    Directory of Open Access Journals (Sweden)

    Chen Eric Y

    2012-01-01

    Full Text Available Abstract Background Histamine released from mast cells, through complex interactions involving the binding of IgE to FcεRI receptors and the subsequent intracellular Ca2+ signaling, can mediate many allergic/inflammatory responses. The possibility of titanium dioxide nanoparticles (TiO2 NPs, a nanomaterial pervasively used in nanotechnology and pharmaceutical industries, to directly induce histamine secretion without prior allergen sensitization has remained uncertain. Results TiO2 NP exposure increased both histamine secretion and cytosolic Ca2+ concentration ([Ca2+]C in a dose dependent manner in rat RBL-2H3 mast cells. The increase in intracellular Ca2+ levels resulted primarily from an extracellular Ca2+ influx via membrane L-type Ca2+ channels. Unspecific Ca2+ entry via TiO2 NP-instigated membrane disruption was demonstrated with the intracellular leakage of a fluorescent calcein dye. Oxidative stress induced by TiO2 NPs also contributed to cytosolic Ca2+ signaling. The PLC-IP3-IP3 receptor pathways and endoplasmic reticulum (ER were responsible for the sustained elevation of [Ca2+]C and histamine secretion. Conclusion Our data suggests that systemic circulation of NPs may prompt histamine release at different locales causing abnormal inflammatory diseases. This study provides a novel mechanistic link between environmental TiO2 NP exposure and allergen-independent histamine release that can exacerbate manifestations of multiple allergic responses.

  7. Estimation of TiO₂ nanoparticle-induced genotoxicity persistence and possible chronic gastritis-induction in mice.

    Science.gov (United States)

    Mohamed, Hanan Ramadan Hamad

    2015-09-01

    Titanium dioxide (TiO2) nanoparticles are widely used as a food additive and coloring agent in many consumer products however limited data is available on the nano-TiO2 induced genotoxicity persistence. Thus, this study investigated the persistence of nano-TiO2 induced genotoxicity and possible induction of chronic gastritis in mice. The mice were orally administered 5, 50 or 500 mg/kg body weight nano-TiO2 for five consecutive days, and then mice from each dosage group were sacrificed 24 h or one or two weeks after the last treatment. The administration of nano-TiO2 resulted in persistent apoptotic DNA fragmentation and mutations in p53 exons (5-8) as well as significant persistent elevations in malondialdehyde and nitric oxide levels and decreases in the reduced glutathione level and catalase activity compared with the control mice in a dose- and time-dependent manner. Necrosis and inflammation were evident upon histological examination. These findings could be attributed to the persistent accumulation of nano-TiO2 at the tested doses at all three time points. Based on these findings, we conclude that the administration of nano-TiO2, even at low doses, leads to persistent accumulation of nano-TiO2 in mice, resulting in persistent inflammation, apoptosis and oxidative stress, ultimately leading to the induction of chronic gastritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Anti-biofilm activity of biogenic selenium nanoparticles and selenium dioxide against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis.

    Science.gov (United States)

    Shakibaie, Mojtaba; Forootanfar, Hamid; Golkari, Yaser; Mohammadi-Khorsand, Tayebe; Shakibaie, Mohammad Reza

    2015-01-01

    The aim of the present study was to investigate the anti-biofilm activity of biologically synthesized selenium nanoparticles (Se NPs) against the biofilm produced by clinically isolated bacterial strains compared to that of selenium dioxide. Thirty strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis were isolated from various specimens of the patients hospitalized in different hospitals (Kerman, Iran). Quantification of the biofilm using microtiter plate assay method introduced 30% of S. aureus, 13% of P. aeruginosa and 17% of P. mirabilis isolates as severely adherent strains. Transmission electron micrograph (TEM) of the purified Se NPs (produced by Bacillus sp. MSh-1) showed individual and spherical nano-structure in the size range of 80-220nm. Obtained results of the biofilm formation revealed that selenium nanoparticles inhibited the biofilm of S. aureus, P. aeruginosa, and P. mirabilis by 42%, 34.3%, and 53.4%, respectively, compared to that of the non-treated samples. Effect of temperature and pH on the biofilm formation in the presence of Se NPs and SeO2 was also evaluated. Copyright © 2014 Elsevier GmbH. All rights reserved.

  9. The influence of adding modified zirconium oxide-titanium dioxide nano-particles on mechanical properties of orthodontic adhesive: an in vitro study.

    Science.gov (United States)

    Felemban, Nayef H; Ebrahim, Mohamed I

    2017-01-13

    The purpose of this in-vitro study was to examine the effect of incorporating different concentrations of Zirconium oxide-Titanium dioxide (ZrO2-TiO2) nanoparticles, which can have antibacterial properties, on the mechanical properties of an orthodontic adhesive. ZrO2-TiO2 (Zirconium oxide, HWNANO, Hongwu International Group Ltd, China) -Titanium dioxide, Nanoshell, USA) nanopowder were incorporated into orthodontic adhesive (Transbond XT, 3 M Unitek, Monrovia, USA) with different concentrations (0.5% weight nonofiller and 1% weight nanofiller). The size of nanoparticle was 70-80 nm for ZrO2 and less than 50 nm for TiO2. For measuring the shear bond strength of the three groups of orthodontic adhesives [Transbond (control), Transbond mixed with 0.5% weight ZrO2-TiO2, and Transbond mixed with 1% weight ZrO2-TiO2], 30 freshly extracted human first premolars were used and bonded with stainless steel metal brackets (Dentaurum®, Discovery®, Deutschland), using the 3 orthodontic adhesives and 3 M Unitek; Transbond TM Plus Self-Etching Primer (10 samples in each group). The recorded values of compressive strength and tensile strength (measured separately on 10 samples of orthodontic adhesives (add the 3 D size of sample, light cured for 40 s on both sides) of each orthodontic adhesives), as well as the shear bond strength in Mega Pascal unit (MPa) were collected and exposed to one-way analysis of variance (ANOVA) and Tukey's post-hoc tests. orthodontic adhesive with 1% weight ZrO2-TiO2 showed the highest mean compressive (73.42 ± 1.55 MPa, p: 0.003, F: 12.74), tensile strength (8.65 ± 0.74 MPa, p: 0.001, F: 68.20), and shear bond strength (20.05 ± 0.2 MPa, p: 0.001, F: 0.17). Adding ZrO2-TiO2 nanoparticle to orthodontic adhesive increased compressive strength, tensile strength, and shear bond strength in vitro, but in vivo studies and randomized clinical trials are needed to validate the present findings.

  10. Titanium Dioxide Nanoparticle-Based Interdigitated Electrodes: A Novel Current to Voltage DNA Biosensor Recognizes E. coli O157:H7.

    Directory of Open Access Journals (Sweden)

    Sh Nadzirah

    Full Text Available Nanoparticle-mediated bio-sensing promoted the development of novel sensors in the front of medical diagnosis. In the present study, we have generated and examined the potential of titanium dioxide (TiO2 crystalline nanoparticles with aluminium interdigitated electrode biosensor to specifically detect single-stranded E.coli O157:H7 DNA. The performance of this novel DNA biosensor was measured the electrical current response using a picoammeter. The sensor surface was chemically functionalized with (3-aminopropyl triethoxysilane (APTES to provide contact between the organic and inorganic surfaces of a single-stranded DNA probe and TiO2 nanoparticles while maintaining the sensing system's physical characteristics. The complement of the target DNA of E. coli O157:H7 to the carboxylate-probe DNA could be translated into electrical signals and confirmed by the increased conductivity in the current-to-voltage curves. The specificity experiments indicate that the biosensor can discriminate between the complementary sequences from the base-mismatched and the non-complementary sequences. After duplex formation, the complementary target sequence can be quantified over a wide range with a detection limit of 1.0 x 10(-13M. With target DNA from the lysed E. coli O157:H7, we could attain similar sensitivity. Stability of DNA immobilized surface was calculated with the relative standard deviation (4.6%, displayed the retaining with 99% of its original response current until 6 months. This high-performance interdigitated DNA biosensor with high sensitivity, stability and non-fouling on a novel sensing platform is suitable for a wide range of biomolecular interactive analyses.

  11. Ameliorative Effects of Dimetylthiourea and N-Acetylcysteine on Nanoparticles Induced Cyto-Genotoxicity in Human Lung Cancer Cells-A549

    Science.gov (United States)

    Srivastava, Ritesh Kumar; Rahman, Qamar; Kashyap, Mahendra Pratap; Lohani, Mohtashim; Pant, Aditya Bhushan

    2011-01-01

    We study the ameliorative potential of dimetylthiourea (DMTU), an OH• radical trapper and N-acetylcysteine (NAC), a glutathione precursor/H2O2 scavenger against titanium dioxide nanoparticles (TiO2-NPs) and multi-walled carbon nanotubes (MWCNTs) induced cyto-genotoxicity in cultured human lung cancer cells-A549. Cytogenotoxicity was induced by exposing the cells to selected concentrations (10 and 50 µg/ml) of either of TiO2-NPs or MWCNTs for 24 h. Anti-cytogenotoxicity effects of DMTU and NAC were studied in two groups, i.e., treatment of 30 minutes prior to toxic insult (short term exposure), while the other group received DMTU and NAC treatment during nanoparticles exposure, i.e., 24 h (long term exposure). Investigations were carried out for cell viability, generation of reactive oxygen species (ROS), micronuclei (MN), and expression of markers of oxidative stress (HSP27, CYP2E1), genotoxicity (P53) and CYP2E1 dependent n- nitrosodimethylamine-demethylase (NDMA-d) activity. In general, the treatment of both DMTU and NAC was found to be effective significantly against TiO2-NPs and MWCNTs induced cytogenotoxicity in A549 cells. Long-term treatment of DMTU and NAC during toxic insults has shown better prevention than short-term pretreatment. Although, cells responded significantly to both DMTU and NAC, but responses were chemical specific. In part, TiO2-NPs induced toxic responses were mediated through OH• radicals generation and reduction in the antioxidant defense system. While in the case of MWCNTs, adverse effects were primarily due to altering/hampering the enzymatic antioxidant system. Data indicate the applicability of human lung cancer cells-A549 as a pre-screening tool to identify the target specific prophylactic and therapeutic potential of drugs candidate molecules against nanoparticles induced cellular damages. PMID:21980536

  12. Ameliorative effects of dimetylthiourea and N-acetylcysteine on nanoparticles induced cyto-genotoxicity in human lung cancer cells-A549.

    Directory of Open Access Journals (Sweden)

    Ritesh Kumar Srivastava

    Full Text Available We study the ameliorative potential of dimetylthiourea (DMTU, an OH• radical trapper and N-acetylcysteine (NAC, a glutathione precursor/H₂O₂ scavenger against titanium dioxide nanoparticles (TiO₂-NPs and multi-walled carbon nanotubes (MWCNTs induced cyto-genotoxicity in cultured human lung cancer cells-A549. Cytogenotoxicity was induced by exposing the cells to selected concentrations (10 and 50 µg/ml of either of TiO₂-NPs or MWCNTs for 24 h. Anti-cytogenotoxicity effects of DMTU and NAC were studied in two groups, i.e., treatment of 30 minutes prior to toxic insult (short term exposure, while the other group received DMTU and NAC treatment during nanoparticles exposure, i.e., 24 h (long term exposure. Investigations were carried out for cell viability, generation of reactive oxygen species (ROS, micronuclei (MN, and expression of markers of oxidative stress (HSP27, CYP2E1, genotoxicity (P⁵³ and CYP2E1 dependent n- nitrosodimethylamine-demethylase (NDMA-d activity. In general, the treatment of both DMTU and NAC was found to be effective significantly against TiO₂-NPs and MWCNTs induced cytogenotoxicity in A549 cells. Long-term treatment of DMTU and NAC during toxic insults has shown better prevention than short-term pretreatment. Although, cells responded significantly to both DMTU and NAC, but responses were chemical specific. In part, TiO₂-NPs induced toxic responses were mediated through OH• radicals generation and reduction in the antioxidant defense system. While in the case of MWCNTs, adverse effects were primarily due to altering/hampering the enzymatic antioxidant system. Data indicate the applicability of human lung cancer cells-A549 as a pre-screening tool to identify the target specific prophylactic and therapeutic potential of drugs candidate molecules against nanoparticles induced cellular damages.

  13. Functionalization of nanoparticle titanium dioxide with different bifunctional organic molecules and trimers of transition compounds for obtaining new materials

    International Nuclear Information System (INIS)

    Rivera Martinez, Maria Cinthya

    2012-01-01

    Functionalization of titanium dioxide in nanoporous anatase phase is investigated for obtaining new nanomaterials. Functionalizations were performed using two heating methods: the conventional of refluxing heating method and microwave irradiation with bifunctional organic molecules is used to study how to anchor molecules and the change in the wettability of the material. Besides, reactions with organic molecules were performed as the derived from nanoproxene. The growth layer by layer is performed using the bifunctional molecules previous for the immobilization of cobalt trimers. Functionalized molecules were characterized by infrared spectroscopy, X-ray diffraction, contact angle, scanning electron microscopy, x-ray elemental analysis, plasma atomic emission spectroscopy coupled inductively, x-ray photoelectron spectroscopy and thermogravimetric analysis. This type of functionalizations on nanoporous titanium dioxide could potentially improve optical sensitivity and activity of this nanomaterial in the visible region. (author) [es

  14. Efficacy of piroxicam plus cisplatin-loaded PLGA nanoparticles in inducing apoptosis in mesothelioma cells.

    Science.gov (United States)

    Menale, Ciro; Piccolo, Maria Teresa; Favicchia, Ilaria; Aruta, Maria Grazia; Baldi, Alfonso; Nicolucci, Carla; Barba, Vincenzo; Mita, Damiano Gustavo; Crispi, Stefania; Diano, Nadia

    2015-02-01

    Combined treatment based on cisplatin-loaded Poly(D,L-lactic-co-glicolic)acid (PLGA) nanoparticles (NP-C) plus the NSAID piroxicam was used as novel treatment for mesothelioma to reduce side effects related to cisplatin toxicity. PLGA nanoparticles were prepared by double emulsion solvent evaporation method. Particle size, drug release profile and in vitro cellular uptake were characterized by TEM, DLS, LC/MS and fluorescence microscopy. MSTO-211H cell line was used to analyse NP-C biological efficacy by FACS and protein analysis. Cisplatin was encapsulated in 197 nm PLGA nanoparticles with 8.2% drug loading efficiency and 47% encapsulation efficiency. Cisplatin delivery from nanoparticles reaches 80% of total encapsulated drug in 14 days following a triphasic trend. PLGA nanoparticles in MSTO-211H cells were localized in the perinuclear space NP-C in combination with piroxicam induced apoptosis using a final cisplatin concentration 1.75 fold less than free drug. Delivered cisplatin cooperated with piroxicam in modulating cell cycle regulators as caspase-3, p53 and p21. Cisplatin loaded PLGA nanoparticles plus piroxicam showed a good efficacy in exerting cytotoxic activity and inducing the same molecular apoptotic effects of the free drugs. Sustained cisplatin release allowed to use less amount of drug, decreasing toxic side effects. This novel approach could represent a new strategy for mesothelioma treatment.

  15. Structural analysis of platinum-palladium nanoparticles dispersed on titanium dioxide to evaluate cyclo-olefines reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, N., E-mail: necastillo@yahoo.co [Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Edificio B, 04510 Mexico DF (Mexico); Centro de Investigacion y de Estudios Avanzados del IPN, Depto. de Fisica, Av. IPN 2508, C.P. 07360, Mexico DF (Mexico); Perez, R. [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Campus Morelos, 62251 Cuernavaca Morelos (Mexico); Martinez-Ortiz, M.J.; Diaz-Barriga, L. [Instituto Politecnico Nacional - ESIQIE, UPALM Edif. 7, 07738 Mexico DF (Mexico); Garcia, L. [Instituto Politecnico Nacional - ESIT, UPALM, 07738 Mexico DF (Mexico); Conde-Gallardo, A. [Centro de Investigacion y de Estudios Avanzados del IPN, Depto. de Fisica, Av. IPN 2508, C.P. 07360, Mexico DF (Mexico)

    2010-04-16

    Structural and chemical properties were correlated to explain catalytic behavior of Pt-Pd/TiO{sub 2} in a cyclo-olefin reaction. Bimetallic nanoparticles supported on TiO{sub 2} were prepared by wetness impregnation techniques at different concentrations of Pt and Pd {approx}1 metallic wt%. The physicochemical properties of these metallic nanoparticles supported on TiO{sub 2} were characterized by N{sub 2} physisorption (Brunauer-Emmett-Teller-BET), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The relationship between chemical composition, physicochemical properties and particle size on the cyclo-olefin reaction was then studied. XRD and TEM results show that these nanoparticles are composed of Pt-Pd with FFC structure (a = 0.389-0.391 nm) supported on TiO{sub 2} (anatase-like structure), and the materials present tetragonal structure nanoparticles (a = 0.37842, b = 0.37842, c = 0.95146 nm). Samples with higher contents of platinum and particle sizes of 4.2 nm show the highest catalytic conversion in cyclo-olefins reaction. Finally, structural examinations of Pt{sub x}-Pd{sub (1-x)}/TiO{sub 2} based system was then conducted to study the effects of metals on the nanostructure of the materials.

  16. Structural analysis of platinum-palladium nanoparticles dispersed on titanium dioxide to evaluate cyclo-olefines reactivity

    International Nuclear Information System (INIS)

    Castillo, N.; Perez, R.; Martinez-Ortiz, M.J.; Diaz-Barriga, L.; Garcia, L.; Conde-Gallardo, A.

    2010-01-01

    Structural and chemical properties were correlated to explain catalytic behavior of Pt-Pd/TiO 2 in a cyclo-olefin reaction. Bimetallic nanoparticles supported on TiO 2 were prepared by wetness impregnation techniques at different concentrations of Pt and Pd ∼1 metallic wt%. The physicochemical properties of these metallic nanoparticles supported on TiO 2 were characterized by N 2 physisorption (Brunauer-Emmett-Teller-BET), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The relationship between chemical composition, physicochemical properties and particle size on the cyclo-olefin reaction was then studied. XRD and TEM results show that these nanoparticles are composed of Pt-Pd with FFC structure (a = 0.389-0.391 nm) supported on TiO 2 (anatase-like structure), and the materials present tetragonal structure nanoparticles (a = 0.37842, b = 0.37842, c = 0.95146 nm). Samples with higher contents of platinum and particle sizes of 4.2 nm show the highest catalytic conversion in cyclo-olefins reaction. Finally, structural examinations of Pt x -Pd (1-x) /TiO 2 based system was then conducted to study the effects of metals on the nanostructure of the materials.

  17. Stability and Aggregation of Silver and Titanium Dioxide Nanoparticles in Seawater: Role of Salinity and Dissolved Organic Matter

    Science.gov (United States)

    The behavior and fate of nanoparticles (NPs) in the marine environment is largely unknown and has the potential to have important environmental and human health implications. The aggregation state and fate of NPs in the marine environment is greatly influenced by their interactio...

  18. High-density platinum nanoparticle-decorated titanium dioxide nanofiber networks for efficient capillary photocatalytic hydrogen generation

    Science.gov (United States)

    Zhaodong Li; Chunhua Yao; Yi-Cheng Wang; Solomon Mikael; Sundaram Gunasekaran; Zhenqiang Ma; Zhiyong Cai; Xudong Wang

    2016-01-01

    Aldehyde-functionalized cellulose nanofibers (CNFs) were applied to synthesize Pt nanoparticles (NPs) on CNF surfaces via on-site Pt ion reduction and achieve high concentration and uniform Pt NP loading. ALD could then selectively deposit TiO2 on CNFs and keep the Pt NPs uncovered due to their drastically different hydro-affinity properties. The...

  19. Ultrasound-induced inertial cavitation from gas-stabilizing nanoparticles.

    Science.gov (United States)

    Kwan, J J; Graham, S; Myers, R; Carlisle, R; Stride, E; Coussios, C C

    2015-08-01

    The understanding of cavitation from nanoparticles has been hindered by the inability to control nanobubble size. We present a method to manufacture nanoparticles with a tunable single hemispherical depression (nanocups) of mean diameter 90, 260, or 650 nm entrapping a nanobubble. A modified Rayleigh-Plesset crevice model predicts the inertial cavitation threshold as a function of cavity size and frequency, and is verified experimentally. The ability to tune cavitation nanonuclei and predict their behavior will be useful for applications ranging from cancer therapy to ultrasonic cleaning.

  20. High ordered biomineralization induced by carbon nanoparticles in the sea urchin Paracentrotus lividus

    International Nuclear Information System (INIS)

    Manno, Daniela; Buccolieri, Alessandro; Filippo, Emanuela; Serra, Antonio; Carata, Elisabetta; Tenuzzo, Bernadetta A; Panzarini, Elisa; Dini, Luciana; Rossi, Marco

    2012-01-01

    A surprising and unexpected biomineralization process was observed during toxicological assessment of carbon nanoparticles on Paracentrotus lividus (sea urchin) pluteus larvae. The larvae activate a process of defense against external material, by incorporating the nanoparticles into microstructures of aragonite similarly to pearl oysters. Aiming at a better understanding of this phenomenon, the larvae were exposed to increasing concentrations of carbon nanoparticles and the biomineralization products were analyzed by electron microscopy, x-ray diffraction and Raman spectroscopy. In order to evaluate the possible influence of Sp-CyP-1 expression on this biomineralization process by larvae, analyses of gene expression (Sp-CyP-1) and calcein labeling were performed. Overall, we report experimental evidence about the capability of carbon nanoparticles to induce an increment of Sp-CyP-1 expression with the consequent activation of a biomineralization process leading to the production of a new pearl-like biomaterial never previously observed in sea urchins. (paper)

  1. Induced Magnetic Anisotropy in Liquid Crystals Doped with Resonant Semiconductor Nanoparticles

    Directory of Open Access Journals (Sweden)

    Vicente Marzal

    2016-01-01

    Full Text Available Currently, there are many efforts to improve the electrooptical properties of liquid crystals by means of doping them with different types of nanoparticles. In addition, liquid crystals may be used as active media to dynamically control other interesting phenomena, such as light scattering resonances. In this sense, mixtures of resonant nanoparticles hosted in a liquid crystal could be a potential metamaterial with interesting properties. In this work, the artificial magnetism induced in a mixture of semiconductor nanoparticles surrounded by a liquid crystal is analyzed. Effective magnetic permeability of mixtures has been obtained using the Maxwell-Garnett effective medium theory. Furthermore, permeability variations with nanoparticles size and their concentration in the liquid crystal, as well as the magnetic anisotropy, have been studied.

  2. Femtosecond Laser-Induced Formation of Wurtzite Phase ZnSe Nanoparticles in Air

    Directory of Open Access Journals (Sweden)

    Hsuan I Wang

    2012-01-01

    Full Text Available We demonstrate an effective method to prepare wurtzite phase ZnSe nanoparticles from zincblende ZnSe single crystal using femtosecond pulse laser ablation. The fabricated ZnSe nanoparticles are in spherical shape and uncontaminated while synthesized under ambient environment. By controlling the laser fluences, the average size of ZnSe nanoparticles can be varied from ~16 nm to ~22 nm in diameter. In Raman spectra, the surface phonon mode becomes dominant in the smaller average particle size with uniform size distribution. The interesting phase transition from the zinc blende structure of ZnSe single crystal to wurtzite structure of ZnSe nanoparticles may have been induced by the ultrahigh ablation pressure at the local area due to the sudden injection of high energy leading to solid-solid transition.

  3. Celastrol nanoparticles inhibit corneal neovascularization induced by suturing in rats

    Directory of Open Access Journals (Sweden)

    Li ZR

    2012-03-01

    Full Text Available Zhanrong Li1, Lin Yao1, Jingguo Li2, Wenxin Zhang1, Xianghua Wu1, Yi Liu1, Miaoli Lin1, Wenru Su1, Yongping Li1, Dan Liang11State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, 2School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of ChinaPurpose: Celastrol, a traditional Chinese medicine, is widely used in anti-inflammation and anti-angiogenesis research. However, the poor water solubility of celastrol restricts its further application. This paper aims to study the effect of celastrol nanoparticles (CNPs on corneal neovascularization (CNV and determine the possible mechanism.Methods: To improve the hydrophilicity of celastrol, celastrol-loaded poly(ethylene glycol-block-poly(ε-caprolactone nanopolymeric micelles were developed. The characterization of CNPs was measured by dynamic light scattering and transmission electron microscopy analysis. Celastrol loading content and release were assessed by ultraviolet-visible analysis and high performance liquid chromatography, respectively. In vitro, human umbilical vein endothelial cell proliferation and capillary-like tube formation were assayed. In vivo, suture-induced CNV was chosen to evaluate the effect of CNPs on CNV in rats. Immunohistochemistry for CD68 assessed the macrophage infiltration of the cornea on day 6 after surgery. Real-time quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were used to evaluate the messenger ribonucleic acid and protein levels, respectively, of vascular endothelial growth factor, matrix metalloproteinase 9, and monocyte chemoattractant protein 1 in the cornea.Results: The mean diameter of CNPs with spherical shape was 48 nm. The celastrol loading content was 7.36%. The release behavior of CNPs in buffered solution (pH 7.4 showed a typical two-phase release profile. CNPs inhibited the proliferation of human umbilical vein endothelial

  4. Peripheral blood picture changes induced by chronic radone and silicon dioxide treatment (in combination or separately)

    International Nuclear Information System (INIS)

    Ivanov, Z.; Dermendzhiev, Kh.; Nikolova, M.

    1975-01-01

    Peripheral blood changes have been studied in rats after the following treatments: 4 hours daily for six months with a radon concentration of 1.10 -10 Ci/1 (group I), 1.10 -12 Ci/1 (group II) 50 mg pure silicon dioxide in 1 ml physiological solution (group III), and intratracheal incorporation of radon concentration in air of 1.10 -10 Ci/1 and silicon dioxide (group IV). Examinations during the third and sixth month after the start of experiment showed development of leukopenia in groups I, III and IV; lymphopenia was established in groups I and IV, and lymphocytosis in group III. Atypical morphological changes were observed in red blood cells. (A.B.)

  5. Re: Engineered Nanoparticles Induce Cell Apoptosis: Potential for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Fehmi Narter

    2016-09-01

    Full Text Available Engineered nanoparticles (ENPs have been widely applied in industry, biology and medicine recently (i.e. clothes, sunscreens, cosmetics, foods, diagnostic medicine, imaging and drug delivery. There are many kinds of manufactured nanomaterial products including TiO2, ZnO, CeO2, Fe2O3, and CuO (as metal oxide nanoparticles as well as gold, silver, platinum and palladium (as metal nanoparticles, and other carbon-based ENP’s such as carbon nanotububes and quantum dots. ENPs with their sizes no larger than 100 nm are able to enter the human body and accumulate in organs and cause toxic effects. In many researches, ENP effects on the cancer cells of different organs with related cell apoptosis were noted (AgNP, nano-Cr2O3, Au-Fe2O3 NPs, nano-TiO2, nano-HAP, nano-Se, MoO3 nanoplate, Realgar nanoparticles. ENPs, with their unique properties, such as surface charge, particle size, composition and surface modification with tissue recognition ligands or antibodies, has been increasingly explored as a tool to carry small molecular weight drugs as well as macromolecules for cancer therapy, thus generating the new concept “nanocarrier”. Direct induction of cell apoptosis by ENPs provides an opportunity for cancer treatment. In the century of nanomedicine that depends on development of the nanotechnology, ENPs have a great potential for application in cancer treatment with minimal side effects.

  6. Carbonation acceleration of calcium hydroxide nanoparticles: induced by yeast fermentation

    Science.gov (United States)

    Lopez-Arce, Paula; Zornoza-Indart, Ainara

    2015-09-01

    Carbonation of Ca(OH)2 nanoparticles and consolidation of limestone are accelerated by high humidity and a yeast fermentation system that supplies a saturated atmosphere on CO2, H2O vapor and ethanol during 28 days. Nanoparticles were analyzed by X-ray diffraction and differential thermal analyses with thermogravimetry. Spectrophotometry, scanning electron microscopy analyses, and hydric and mechanical tests were also performed in stones specimens. Samples exposed to the yeast environment achieve 100 % relative CaCO3 yield, whereas at high humidity but without the yeast and under laboratory environment, relative yields of 95 % CaCO3 and 15 % CaCO3 are, respectively, reached, with white crusts and glazing left on the stone surfaces when the nanoparticles are applied at a concentration of 25 g/l. The largest increase in the drilling resistance and surface hardness values with slight increase in the capillarity absorption and desorption coefficients and with lesser stone color changes are produced at a concentration of 5 g/l, in the yeast system environment. This especially happens in stone specimens initially with bimodal pore size distributions, more amounts of pores with diameters between 0.1 and 1 µm, higher open porosity values and faster capillary coefficients. An inexpensive and reliable method based on water and yeast-sugar solution is presented to speed up carbonation of Ca(OH)2 nanoparticles used as a consolidating product to improve the mechanical properties of decayed limestone from archaeological and architectural heritage.

  7. The bioaccumulation and toxicity induced by gold nanoparticles in ...

    African Journals Online (AJOL)

    It is essential to characterize the bioaccumulation and toxicity of gold nanoparticles (GNPs) in blood prior to using them in drug delivery, diagnostics, and treatment. The aim of the present study was to evaluate the blood absorbance spectra after intraperitoneal administration of 50 μl of 10, 20, and 50 nm GNPs in rat for ...

  8. Carbon black nanoparticles induce type II epithelial cells to release chemotaxins for alveolar macrophages

    Directory of Open Access Journals (Sweden)

    Donaldson Ken

    2005-12-01

    Full Text Available Abstract Background Alveolar macrophages are a key cell in dealing with particles deposited in the lungs and in determining the subsequent response to that particle exposure. Nanoparticles are considered a potential threat to the lungs and the mechanism of pulmonary response to nanoparticles is currently under intense scrutiny. The type II alveolar epithelial cell has previously been shown to release chemoattractants which can recruit alveolar macrophages to sites of particle deposition. The aim of this study was to assess the responses of a type II epithelial cell line (L-2 to both fine and nanoparticle exposure in terms of secretion of chemotactic substances capable of inducing macrophage migration. Results Exposure of type II cells to carbon black nanoparticles resulted in significant release of macrophage chemoattractant compared to the negative control and to other dusts tested (fine carbon black and TiO2 and nanoparticle TiO2 as measured by macrophage migration towards type II cell conditioned medium. SDS-PAGE analysis of the conditioned medium from particle treated type II cells revealed that a higher number of protein bands were present in the conditioned medium obtained from type II cells treated with nanoparticle carbon black compared to other dusts tested. Size-fractionation of the chemotaxin-rich supernatant determined that the chemoattractants released from the epithelial cells were between 5 and 30 kDa in size. Conclusion The highly toxic nature and reactive surface chemistry of the carbon black nanoparticles has very likely induced the type II cell line to release pro-inflammatory mediators that can potentially induce migration of macrophages. This could aid in the rapid recruitment of inflammatory cells to sites of particle deposition and the subsequent removal of the particles by phagocytic cells such as macrophages and neutrophils. Future studies in this area could focus on the exact identity of the substance(s released by the

  9. 3D characterization of coal strains induced by compression, carbon dioxide sorption, and desorption at in-situ stress conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pone, J. Denis N.; Halleck, Phillip M.; Mathews, Jonathan P. [Department of Energy and Mineral Engineering and The EMS Energy Institute, The Pennsylvania State University, University Park, PA 16802 (United States)

    2010-06-01

    Sequestration of carbon dioxide in unmineable coal seams is an option to combat climate change and an opportunity to enhance coalbed methane production. Prediction of sequestration potential in coal requires characterization of porosity, permeability, sorption capacity and the magnitude of swelling due to carbon dioxide uptake or shrinkage due to methane and water loss. Unfortunately, the majority of data characterizing coal-gas systems have been obtained from powdered, unconfined coal samples. Little is known about confined coal behavior during carbon dioxide uptake and methane desorption. The present work focuses on the characterization of lithotype specific deformation, and strain behavior during CO{sub 2} uptake at simulated in-situ stress conditions. It includes the evaluation of three-dimensional strain induced by the confining stress, the sorption, and the desorption of carbon dioxide. X-ray computed tomography allowed three-dimensional characterization of the bituminous coal deformation samples under hydrostatic stress. The application of 6.9 MPa of confining stress contributes an average of - 0.34% volumetric strain. Normal strains due to confining stress were - 0.08%, - 0.15% and - 0.11% along the x, y and z axes respectively. Gas injection pressure was 3.1 MPa and the excess sorption was 0.85 mmol/g. Confined coal exposed to CO{sub 2} for 26 days displays an average volumetric expansion of 0.4%. Normal strains due to CO{sub 2} sorption were 0.11%, 0.22% and 0.11% along x, y and z axes. Drainage of the CO{sub 2} induced an average of - 0.33% volumetric shrinkage. Normal strains due to CO{sub 2} desorption were - 0.23%, - 0.08% and - 0.02% along x, y and z axes. Alternating positive and negative strain values observed along the sample length during compression, sorption and desorption respectively emphasized that both localized compression/compaction and expansion of coal will occur during CO{sub 2} sequestration. (author)

  10. Mechanism of solid-state plasma-induced dewetting for formation of copper and gold nanoparticles.

    Science.gov (United States)

    Kwon, Soon-Ho; Choe, Han Joo; Lee, Hyo-Chang; Chung, Chin-Wook; Lee, Jung-Joong

    2013-09-01

    Cu and Au nanoparticles were fabricated by plasma treatment on Cu and Au films at 653 K. The nanoparticles were formed by dewetting the metallic films using plasma. Scanning electron microscopy and transmission electron microscopy investigations showed that the plasma-induced dewetting of the Cu and Au films proceeded through heterogeneous hole nucleation and growth along the grain boundaries to lower the surface energy. The amount of energy transferred to surface atoms by one Ar ion was calculated to be 16.1 eV, which was sufficient for displacing Cu and Au atoms. Compared to thermally activated dewetting, more uniform particles could be obtained by plasma-induced dewetting because a much larger number of holes with smaller sizes was generated. The plasma dewetting process is less sensitive to the oxidation of metallic films compared to the annealing process. As a result, Cu nanoparticles could be fabricated at 653 K, whereas the thermally activated dewetting was not possible.

  11. Spatial Manipulation and Assembly of Nanoparticles by Atomic Force Microscopy Tip-Induced Dielectrophoresis.

    Science.gov (United States)

    Zhou, Peilin; Yu, Haibo; Yang, Wenguang; Wen, Yangdong; Wang, Zhidong; Li, Wen Jung; Liu, Lianqing

    2017-05-17

    In this article, we present a novel method of spatial manipulation and assembly of nanoparticles via atomic force microscopy tip-induced dielectrophoresis (AFM-DEP). This method combines the high-accuracy positioning of AFM with the parallel manipulation of DEP. A spatially nonuniform electric field is induced by applying an alternating current (AC) voltage between the conductive AFM probe and an indium tin oxide glass substrate. The AFM probe acted as a movable DEP tweezer for nanomanipulation and assembly of nanoparticles. The mechanism of AFM-DEP was analyzed by numerical simulation. The effects of solution depth, gap distance, AC voltage, solution concentration, and duration time were experimentally studied and optimized. Arrays of 200 nm polystyrene nanoparticles were assembled into various nanostructures, including lines, ellipsoids, and arrays of dots. The sizes and shapes of the assembled structures were controllable. It was thus demonstrated that AFM-DEP is a flexible and powerful tool for nanomanipulation.

  12. Influence of external magnetic field on laser-induced gold nanoparticles fragmentation

    International Nuclear Information System (INIS)

    Serkov, A. A.; Rakov, I. I.; Simakin, A. V.; Kuzmin, P. G.; Shafeev, G. A.; Mikhailova, G. N.; Antonova, L. Kh.; Troitskii, A. V.; Kuzmin, G. P.

    2016-01-01

    Laser-assisted fragmentation is an efficient method of the nanoparticles size and morphology control. However, its exact mechanisms are still under consideration. One of the remaining problems is the plasma formation, inevitably occurring upon the high intensity laser irradiation. In this Letter, the role of the laser-induced plasma is studied via introduction of high-intensity external magnetic field (up to 7.5 T). Its presence is found to cause the plasma emission to start earlier regarding to a laser pulse, also increasing the plume luminosity. Under these conditions, the acceleration of nanoparticles fragmentation down to a few nanometers is observed. Laser-induced plasma interaction with magnetic field and consequent energy transfer from plasma to nanoparticles are discussed.

  13. A Cu-Zn nanoparticle promoter for selective carbon dioxide reduction and its application in visible-light-active Z-scheme systems using water as an electron donor.

    Science.gov (United States)

    Yin, Ge; Sako, Hiroshi; Gubbala, Ramesh V; Ueda, Shigenori; Yamaguchi, Akira; Abe, Hideki; Miyauchi, Masahiro

    2018-04-17

    Selective carbon dioxide photoreduction to produce formic acid was achieved under visible light irradiation using water molecules as electron donors, similar to natural plants, based on the construction of a Z-scheme light harvesting system modified with a Cu-Zn alloy nanoparticle co-catalyst. The faradaic efficiency of our Z-scheme system for HCOOH generation was over 50% under visible light irradiation.

  14. Manganese Dioxide Coated Graphene Nanoribbons Supported Palladium Nanoparticles as an Efficient Catalyst for Ethanol Electrooxidation in Alkaline Media

    International Nuclear Information System (INIS)

    Liu, Qi; Jiang, Kun; Fan, Jinchen; Lin, Yan; Min, Yulin; Xu, Qunjie; Cai, Wen-Bin

    2016-01-01

    Design of appropriate supporting materials is an alternative route to yield efficient Pt-free catalysts for ethanol oxidation reaction, which in practice may determine the conversion efficiency of direct alkaline ethanol fuel cells. In this work, graphene nanoribbons (GNRs) coated with MnO_2 are used as a unique supporting material for loading and dispersing Pd nanoparticles. XRD, TEM and XPS are applied to characterize the structure of as-synthesized Pd/MnO_2/GNRs nanocomposite catalyst, revealing a good dispersion as well as a modification of electronic property of Pd nanoparticles. Electrochemical measurements demonstrate that the as-synthesized nanocomposite displays largely enhanced electrocatalytic activity and durability toward ethanol oxidation in alkaline media as compared to the other tested Pd-based catalysts with various supports.

  15. Silver-doped manganese dioxide and trioxide nanoparticles inhibit both gram positive and gram negative pathogenic bacteria.

    Science.gov (United States)

    Kunkalekar, R K; Prabhu, M S; Naik, M M; Salker, A V

    2014-01-01

    Palladium, ruthenium and silver-doped MnO2 and silver doped Mn2O3 nanoparticles were synthesized by simple co-precipitation technique. SEM-TEM analysis revealed the nano-size of these synthesized samples. XPS data illustrates that Mn is present in 4+ and 3+ oxidation states in MnO2 and Mn2O3 respectively. Thermal analysis gave significant evidence for the phase changes with increasing temperature. Antibacterial activity of these synthesized nanoparticles on three Gram positive bacterial cultures (Staphylococcus aureus ATCC 6538, Streptococcus epidermis ATCC 12228, Bacillus subtilis ATCC 6633) and three Gram negative cultures (Escherichia coli ATCC 8739, Salmonella abony NCTC 6017 and Klebsiella pneumoniae ATCC 1003) was investigated using a disc diffusion method and live/dead assay. Only Ag-doped MnO2 and Ag-doped Mn2O3 nanoparticles showed antibacterial property against all six-test bacteria but Ag-doped MnO2 was found to be more effective than Ag-doped Mn2O3. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Production of mono- and bimetallic nanoparticles of noble metals by pyrolysis of organic extracts on silicon dioxide

    International Nuclear Information System (INIS)

    Serga, V; Kulikova, L; Cvetkov, A; Krumina, A; Kodols, M; Chornaja, S; Dubencovs, K; Sproge, E

    2013-01-01

    In the present work the influence of the tri-n-octylammonium (Oct 3 NH + ) salt anion (PtCl 6 2- , PdCl 4 2- , AuCl 4 − ) nature on the phase composition and mean size of crystallites of the extract pyrolysis products on the SiO 2 nanopowder has been studied. The XRD phase analysis of the composites (metal loading 2.4 wt.%) made under the same conditions, at the pyrolysis of Pt- and Au-containing extracts has shown the formation of nanoparticles of Pt (d Pt = 15 nm) and Au (d Au = 33 nm), respectively. The end-product of the pyrolysis of the Pd-containing extract has an admixture phase of PdO along with the main metal phase (d Pd = 21 nm). At the preparation of bimetallic particles (Pt-Pd, Pt-Au, Pd-Au) on the SiO 2 nanopowder it has been found that the nanoparticles of the PtPd alloy, Pt and Au or Pd and Au nanoparticles are the products of the thermal decomposition of two-component mixtures of extracts. The investigation of catalytic properties of the produced composites in the reaction of glycerol oxidation by molecular oxygen in alkaline aqueous solutions has shown that all bimetallic composites exhibit catalytic activity in contrast to monometallic ones

  17. Nanoparticle detection in aqueous solutions using Raman and Laser Induced Breakdown Spectroscopy

    NARCIS (Netherlands)

    Sovago, M.; Buis, E.-J.; Sandtke, M.

    2013-01-01

    We show the chemical identification and quantification of the concentration and size of nanoparticle (NP) dispersions in aqueous solutions by using a combination of Raman Spectroscopy and Laser Induced Breakdown Spectroscopy (LIBS). The two spectroscopic techniques are applied to demonstrate the NP

  18. Nanoparticles of barium induce apoptosis in human phagocytes.

    Science.gov (United States)

    Mores, Luana; França, Eduardo Luzia; Silva, Núbia Andrade; Suchara, Eliane Aparecida; Honorio-França, Adenilda Cristina

    2015-01-01

    Nutrients and immunological factors of breast milk are essential for newborn growth and the development of their immune system, but this secretion can contain organic and inorganic toxins such as barium. Colostrum contamination with barium is an important issue to investigate because this naturally occurring element is also associated with human activity and industrial pollution. The study evaluated the administration of barium nanoparticles to colostrum, assessing the viability and functional activity of colostral mononuclear phagocytes. Colostrum was collected from 24 clinically healthy women (aged 18-35 years). Cell viability, superoxide release, intracellular Ca(2+) release, and phagocyte apoptosis were analyzed in the samples. Treatment with barium lowered mononuclear phagocyte viability, increased superoxide release, and reduced intracellular calcium release. In addition, barium increased cell death by apoptosis. These data suggest that nanoparticles of barium in colostrum are toxic to cells, showing the importance of avoiding exposure to this element.

  19. Acoustic stimulation can induce a selective neural network response mediated by piezoelectric nanoparticles

    Science.gov (United States)

    Rojas, Camilo; Tedesco, Mariateresa; Massobrio, Paolo; Marino, Attilio; Ciofani, Gianni; Martinoia, Sergio; Raiteri, Roberto

    2018-06-01

    Objective. We aim to develop a novel non-invasive or minimally invasive method for neural stimulation to be applied in the study and treatment of brain (dys)functions and neurological disorders. Approach. We investigate the electrophysiological response of in vitro neuronal networks when subjected to low-intensity pulsed acoustic stimulation, mediated by piezoelectric nanoparticles adsorbed on the neuronal membrane. Main results. We show that the presence of piezoelectric barium titanate nanoparticles induces, in a reproducible way, an increase in network activity when excited by stationary ultrasound waves in the MHz regime. Such a response can be fully recovered when switching the ultrasound pulse off, depending on the generated pressure field amplitude, whilst it is insensitive to the duration of the ultrasound pulse in the range 0.5 s–1.5 s. We demonstrate that the presence of piezoelectric nanoparticles is necessary, and when applying the same acoustic stimulation to neuronal cultures without nanoparticles or with non-piezoelectric nanoparticles with the same size distribution, no network response is observed. Significance. We believe that our results open up an extremely interesting approach when coupled with suitable functionalization strategies of the nanoparticles in order to address specific neurons and/or brain areas and applied in vivo, thus enabling remote, non-invasive, and highly selective modulation of the activity of neuronal subpopulations of the central nervous system of mammalians.

  20. Doping induced magnetism in Co-ZnS nanoparticles

    International Nuclear Information System (INIS)

    Sambasivam, S.; Paul Joseph, D.; Lin, J.G.; Venkateswaran, C.

    2009-01-01

    Zn 1-x Co x S nanoparticles with x=0, 0.1, 0.2, and 0.3 were synthesized by the co-precipitation method using thiophenol as capping agent. The effect of Co doping on the structural, optical and magnetic properties are investigated. The X-ray diffraction patterns show single phase with cubic structure and the images of Transmission Electron Microscopy indicate an average particle size of 39 nm. Significant blue shift in the optical absorbing band edge was observed with increasing Co doping. In the Co doped samples, room-temperature (RT) magnetic hysteresis is observed and the magnetization reduces with increasing Co content. However, these samples show paramagnetic resonance instead of ferromagnetic resonance at both 300 and 80 K, suggesting that the origin of RT magnetization in these Zn 1-x Co x S nanoparticles involves with the frustration of antiferromagnetic interactions. - Graphical abstract: Figure shows the magnetization data of Zn 1-x Co x S (0.1≤x≤0.3) nanoparticles annealed at 573 K/2 h in vacuum and measured at 300 K. This interesting feature of systematic reduction in magnetization may be due to introduction of antiferromagnetic ordering with increasing 'Co' concentration which may be due to competition between the antiferromagnetic and ferromagnetic ordering within the sample. One could also observe the exchange bias effect which is an interface interaction observed in a ferromagnetic-antiferromagnetic mixture. The exchange bias field (loop shift) towards negative field was around 63 Oe for the Zn 1-x Co x S (0.1≤x≤0.3) nanoparticles.

  1. Thermal induced structural transformation of bimetallic AuPd nanoparticles

    International Nuclear Information System (INIS)

    Bruma, A; Li, Z Y

    2014-01-01

    High Angle Annular Dark Field Scanning Transmission Electron Microscope (HAADF-STEM) has been employed for the study of thermal effects of structural transformation of AuPd nanoparticles produced by physical vapour deposition. Depending on the duration of annealing at a temperature of 500 K, atomic resolved imaging analysis reveals the formation of various structure morphologies from the ordered L1 2 superlattice to the core-shell structure. The effects of Pd-oxides are also discussed

  2. Experimental and statistical analysis of surface charge, aggregation and adsorption behaviors of surface-functionalized titanium dioxide nanoparticles in aquatic system

    Energy Technology Data Exchange (ETDEWEB)

    Xiang Chengcheng [West Virginia University, Department of Mechanical and Aerospace Engineering, WVNano Initiative (United States); Yang Feng, E-mail: feng.yang@mail.wvu.edu [West Virginia University, Department of Industrial and Management Systems Engineering (United States); Li Ming [West Virginia University, Department of Mechanical and Aerospace Engineering, WVNano Initiative (United States); Jaridi, Majid [West Virginia University, Department of Industrial and Management Systems Engineering (United States); Wu Nianqiang, E-mail: nick.wu@mail.wvu.edu [West Virginia University, Department of Mechanical and Aerospace Engineering, WVNano Initiative (United States)

    2013-01-15

    One hundred and fifty nanometers sized anatase titanium dioxide nanoparticles (TiO{sub 2} NPs) have been functionalized with the -CH{sub 3}, -NH{sub 2}, -SH, -OH, -COOH, and -SO{sub 3}H terminal groups. Surface charge, aggregation, and adsorption behaviors of the functionalized NPs in aquatic phase have been investigated by a set of experiments following the full factorial design. The dependence of surface charge, suspension size, and surface adsorption upon the various factors (including surface chemistry of NPs, the pH value, and ionic strength of an aqueous solution) has been studied with the statistical methods such as multiple linear regressions and multiple comparison tests. The surface functional group on the TiO{sub 2} NPs affects the characteristics in the simulated aquatic environment. The correlations among the characteristics of NPs have also been investigated by obtaining Pearson's correlation coefficient. The hydrodynamic size is negatively correlated with the absolute value of zeta potential, and positively correlated with the ionic strength. In the NaCl solution, the charge screening effect is responsible for the aggregation. In the CaCl{sub 2} solution, the charge screening effect is dominant mechanism for aggregation at a low salt concentration. In contrast, the interaction between Ca{sup 2+} ions and the specific functional group plays a significant role at a high salt concentration. The adsorption efficiency of humic acid decreases with an increase in the pH value, whereas increases with an increase in the ionic strength. The adsorption efficiency is positively correlated with the zeta potential. The statistical analysis methods and the results have implications in assessment of potential environmental risks posed by engineered nanoparticles.

  3. Ultrasonic assisted dispersive solid-phase microextraction of Eriochrome Cyanine R from water sample on ultrasonically synthesized lead (II) dioxide nanoparticles loaded on activated carbon: Experimental design methodology.

    Science.gov (United States)

    Bahrani, Sonia; Ghaedi, Mehrorang; Mansoorkhani, Mohammad Javad Khoshnood; Asfaram, Arash; Bazrafshan, Ali Akbar; Purkait, Mihir Kumar

    2017-01-01

    The present research focus on designing an appropriate dispersive solid-phase microextraction (UA-DSPME) for preconcentration and determination of Eriochrome Cyanine R (ECR) in aqueous solutions with aid of sonication using lead (II) dioxide nanoparticles loaded on activated carbon (PbO-NPs-AC). This material was fully identified with XRD and SEM. Influence of pH, amounts of sorbent, type and volume of eluent, and sonication time on response properties were investigated and optimized by central composite design (CCD) combined with surface response methodology using STATISTICA. Among different solvents, dimethyl sulfoxide (DMSO) was selected as an efficient eluent, which its combination by present nanoparticles and application of ultrasound waves led to enhancement in mass transfer. The predicted maximum extraction (100%) under the optimum conditions of the process variables viz. pH 4.5, eluent 200μL, adsorbent dosage 2.5mg and 5min sonication was close to the experimental value (99.50%). at optimum conditions some experimental features like wide 5-2000ngmL -1 ECR, low detection limit (0.43ngmL -1 , S/N=3:1) and good repeatability and reproducibility (relative standard deviation, <5.5%, n=12) indicate versatility in successful applicability of present method for real sample analysis. Investigation of accuracy by spiking known concentration of ECR over 200-600ngmL -1 gave mean recoveries from 94.850% to 101.42% under optimal conditions. The procedure was also applied for the p