Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

Energy Technology Data Exchange (ETDEWEB)

Laha, Dipranjan; Pramanik, Arindam [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Laskar, Aparna [CSIR-Indian Institute of Chemical Biology, Kolkata 700032 (India); Jana, Madhurya [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Pramanik, Panchanan [Department of Chemistry, Indian Institute of Technology, Kharagpur 721302 (India); Karmakar, Parimal, E-mail: pkarmakar_28@yahoo.co.in [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India)

2014-11-15

Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain.

Thermosensitive liposomes entrapping iron oxide nanoparticles for controllable drug release

International Nuclear Information System (INIS)

Tai, L-A; Wang, Y-C; Wang, Y-J; Yang, C-S; Tsai, P-J; Lo, L-W

2009-01-01

Iron oxide nanoparticles can serve as a heating source upon alternative magnetic field (AMF) exposure. Iron oxide nanoparticles can be mixed with thermosensitive nanovehicles for hyperthermia-induced drug release, yet such a design and mechanism may not be suitable for controllable drug release applications in which the tissues are susceptible to environmental temperature change such as brain tissue. In the present study, iron oxide nanoparticles were entrapped inside of thermosensitive liposomes for AMF-induced drug release while the environmental temperature was maintained at a constant level. Carboxyfluorescein was co-entrapped with the iron oxide nanoparticles in the liposomes as a model compound for monitoring drug release and environmental temperature was maintained with a water circulator jacket. These experiments have been successfully performed in solution, in phantom and in anesthetized animals. Furthermore, the thermosensitive liposomes were administered into rat forearm skeletal muscle, and the release of carboxylfluorescein triggered by the external alternative magnetic field was monitored by an implanted microdialysis perfusion probe with an on-line laser-induced fluorescence detector. In the future such a device could be applied to simultaneous magnetic resonance imaging and non-invasive drug release in temperature-sensitive applications.

Comparative Study of Different Methods to Determine the Role of Reactive Oxygen Species Induced by Zinc Oxide Nanoparticles

Directory of Open Access Journals (Sweden)

Nigar A. Najim

2016-08-01

Full Text Available Accumulation of reactive oxygen species (ROS followed by an increase in oxidative stress is associated with cellular responses to nanoparticle induced cell damages. Finding the best method for assessing intracellular ROS production is the key step in the detection of oxidative stress induced injury. This study evaluates and compares four different methods for the measurement of intracellular ROS generation using fluorogenic probe, 2´,7´-dichlorofluorescein diacetate (DCFH-DA. Hydrogen peroxide (H2O2 was utilised as a positive control to assess the reactivity of the probe. Spherically shaped zinc oxide (ZnO nanoparticles with an average particle size of 85.7 nm were used to determine the diverse roles of ROS in nanotoxicity in Hs888Lu and U937 cell lines. The results showed that different methods exhibit different patterns of ROS measurement. In conclusion this study found that the time point at which the DCFH-DA is added to the reaction, the incubation time and the oxidative species that is responsible for the oxidation of DCFH, have impact on the intracellular ROS measurement.

Iron nanoparticles increase 7-ketocholesterol-induced cell death, inflammation, and oxidation on murine cardiac HL1-NB cells

Directory of Open Access Journals (Sweden)

Edmond Kahn

2010-03-01

Full Text Available Edmond Kahn1, Mauhamad Baarine2, Sophie Pelloux3, Jean-Marc Riedinger4, Frédérique Frouin1, Yves Tourneur3, Gérard Lizard21INSE RM U678/UMR – S UPMC, IFR 14, CH U Pitié-Salpêtrière, 75634 Paris Cedex 13, France; 2Centre de Recherche INSE RM U866, Equipe Biochimie Métabolique et Nutritionnelle – Université de Bourgogne, Faculté des Sciences Gabriel, 6 Bd Gabriel, 21000 Dijon, France; 3Centre Commun de Quantimétrie, Université Lyon 1; Université de Lyon, Lyon, France; 4Département de Biologie et de Pathologie des Tumeurs, Centre Georges François-Leclerc, 21000 Dijon, FranceObjective: To evaluate the cytotoxicity of iron nanoparticles on cardiac cells and to determine whether they can modulate the biological activity of 7-ketocholesterol (7KC involved in the development of cardiovascular diseases. Nanoparticles of iron labeled with Texas Red are introduced in cultures of nonbeating mouse cardiac cells (HL1-NB with or without 7-ketocholesterol 7KC, and their ability to induce cell death, pro-inflammatory and oxidative effects are analyzed simultaneously.Study design: Flow cytometry (FCM, confocal laser scanning microscopy (CLSM, and subsequent factor analysis image processing (FAMIS are used to characterize the action of iron nanoparticles and to define their cytotoxicity which is evaluated by enhanced permeability to SYTOX Green, and release of lactate deshydrogenase (LDH. Pro-inflammatory effects are estimated by ELISA in order to quantify IL-8 and MCP-1 secretions. Pro-oxidative effects are measured with hydroethydine (HE.Results: Iron Texas Red nanoparticles accumulate at the cytoplasmic membrane level. They induce a slight LDH release, and have no inflammatory or oxidative effects. However, they enhance the cytotoxic, pro-inflammatory and oxidative effects of 7KC. The accumulation dynamics of SYTOX Green in cells is measured by CLSM to characterize the toxicity of nanoparticles. The emission spectra of SYTOX Green and

Concentration-dependent toxicity of iron oxide nanoparticles mediated by increased oxidative stress

Directory of Open Access Journals (Sweden)

Saba Naqvi

2010-11-01

induced by nanoparticles studied using the lactate dehydrogenase assay, showed both concentration- and time-dependent damage. Thus, this study concluded that use of a low optimum concentration of superparamagnetic iron oxide nanoparticles is important for avoidance of oxidative stress-induced cell injury and death.Keywords: superparamagnetic iron oxide nanoparticles, cytotoxicity, MTT assay, J774 cell line

Biologically Synthesized Gold Nanoparticles Ameliorate Cold and Heat Stress-Induced Oxidative Stress in Escherichia coli

Directory of Open Access Journals (Sweden)

Xi-Feng Zhang

2016-06-01

Full Text Available Due to their unique physical, chemical, and optical properties, gold nanoparticles (AuNPs have recently attracted much interest in the field of nanomedicine, especially in the areas of cancer diagnosis and photothermal therapy. Because of the enormous potential of these nanoparticles, various physical, chemical, and biological methods have been adopted for their synthesis. Synthetic antioxidants are dangerous to human health. Thus, the search for effective, nontoxic natural compounds with effective antioxidative properties is essential. Although AuNPs have been studied for use in various biological applications, exploration of AuNPs as antioxidants capable of inhibiting oxidative stress induced by heat and cold stress is still warranted. Therefore, one goal of our study was to produce biocompatible AuNPs using biological methods that are simple, nontoxic, biocompatible, and environmentally friendly. Next, we aimed to assess the antioxidative effect of AuNPs against oxidative stress induced by cold and heat in Escherichia coli, which is a suitable model for stress responses involving AuNPs. The response of aerobically grown E. coli cells to cold and heat stress was found to be similar to the oxidative stress response. Upon exposure to cold and heat stress, the viability and metabolic activity of E. coli was significantly reduced compared to the control. In addition, levels of reactive oxygen species (ROS and malondialdehyde (MDA and leakage of proteins and sugars were significantly elevated, and the levels of lactate dehydrogenase activity (LDH and adenosine triphosphate (ATP significantly lowered compared to in the control. Concomitantly, AuNPs ameliorated cold and heat-induced oxidative stress responses by increasing the expression of antioxidants, including glutathione (GSH, glutathione S-transferase (GST, super oxide dismutase (SOD, and catalase (CAT. These consistent physiology and biochemical data suggest that AuNPs can ameliorate cold and

Redox-active cerium oxide nanoparticles protect human dermal fibroblasts from PQ-induced damage

Directory of Open Access Journals (Sweden)

Claudia von Montfort

2015-04-01

Full Text Available Recently, it has been published that cerium (Ce oxide nanoparticles (CNP; nanoceria are able to downregulate tumor invasion in cancer cell lines. Redox-active CNP exhibit both selective pro-oxidative and antioxidative properties, the first being responsible for impairment of tumor growth and invasion. A non-toxic and even protective effect of CNP in human dermal fibroblasts (HDF has already been observed. However, the effect on important parameters such as cell death, proliferation and redox state of the cells needs further clarification. Here, we present that nanoceria prevent HDF from reactive oxygen species (ROS-induced cell death and stimulate proliferation due to the antioxidative property of these particles.

Iron oxide and gold nanoparticles in cancer therapy

Energy Technology Data Exchange (ETDEWEB)

Gotman, Irena, E-mail: gotman@technion.ac.il; Gutmanas, Elazar Y., E-mail: gutmanas@technion.ac.il [Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa, 32000 Israel (Israel); Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Psakhie, Sergey G. [Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Lozhkomoev, Aleksandr S. [Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

2016-08-02

Continuous research activities in the field of nanomedicine in the past decade have, to a great extent, been focused on nanoparticle technologies for cancer therapy. Gold and iron oxide nanoparticles (NP) are two of the most studied inorganic nanomaterials due to their unique optical and magnetic properties. Both types of NPs are emerging as promising systems for anti-tumor drug delivery and for nanoparticle-mediated thermal therapy of cancer. In thermal therapy, localized heating inside tumors or in proximity of tumor cells can be induced, for example, with Au NPs by radiofrequency ablation heating or conversion of photon energy (photothermal therapy) and in iron oxide magnetic NPs by heat generation through relaxation in an alternating magnetic field (magnetic hyperthermia). Furthermore, the superparamagnetic properties of iron oxide nanoparticles have led to their use as potent MRI (magnetic resonance imaging) contrast agents. Surface modification/coating can produce NPs with tailored and desired properties, such as enhanced blood circulation time, stability, biocompatibility and water solubility. To target nanoparticles to specific tumor cells, NPs should be conjugated with targeting moieties on the surface which bind to receptors or other molecular structures on the cell surface. The article presents several approaches to enhancing the specificity of Au and iron oxide nanoparticles for tumor tissue by appropriate surface modification/functionalization, as well as the effect of these treatments on the saturation magnetization value of iron oxide NPs. The use of other nanoparticles and nanostructures in cancer treatment is also briefly reviewed.

Comparative effects of macro-sized aluminum oxide and aluminum oxide nanoparticles on erythrocyte hemolysis: influence of cell source, temperature, and size

Energy Technology Data Exchange (ETDEWEB)

Vinardell, M. P., E-mail: mpvinardellmh@ub.edu; Sordé, A. [Universitat de Barcelona, Departament de Fisiologia, Facultat de Farmàcia (Spain); Díaz, J. [Universitat de Barcelona CCiT, Scientific and Technological Centers (Spain); Baccarin, T.; Mitjans, M. [Universitat de Barcelona, Departament de Fisiologia, Facultat de Farmàcia (Spain)

2015-02-15

Al{sub 2}O{sub 3} is the most abundantly produced nanomaterial and has been used in diverse fields, including the medical, military, and industrial sectors. As there are concerns about the health effects of nanoparticles, it is important to understand how they interact with cells, and specifically with red blood cells. The hemolysis induced by three commercial nano-sized aluminum oxide particles (nanopowder 13 nm, nanopowder <50 nm, and nanowire 2–6 × 200–400 nm) was compared to aluminum oxide and has been studied on erythrocytes from humans, rats, and rabbits, in order to elucidate the mechanism of action and the influence of size and shape on hemolytic behavior. The concentrations inducing 50 % hemolysis (HC{sub 50}) were calculated for each compound studied. The most hemolytic aluminum oxide particles were of nanopowder 13, followed by nanowire and nanopowder 50. The addition of albumin to PBS induced a protective effect on hemolysis in all the nano-forms of Al{sub 2}O{sub 3}, but not on Al{sub 2}O{sub 3}. The drop in HC{sub 50} correlated to a decrease in nanomaterial size, which was induced by a reduction of aggregation. Aluminum oxide nanoparticles are less hemolytic than other oxide nanoparticles and behave differently depending on the size and shape of the nanoparticles. The hemolytic behavior of aluminum oxide nanoparticles differs from that of aluminum oxide.

Laser-Induced Reductive Sintering of Nickel Oxide Nanoparticles under Ambient Conditions

KAUST Repository

Paeng, Dongwoo; Lee, Daeho; Yeo, Junyeob; Yoo, Jae-Hyuck; Allen, Frances I.; Kim, Eunpa; So, Hongyun; Park, Hee K.; Minor, Andrew M.; Grigoropoulos, Costas P.

2015-01-01

© 2015 American Chemical Society. This work is concerned with the kinetics of laser-induced reductive sintering of nonstoichiometric crystalline nickel oxide (NiO) nanoparticles (NPs) under ambient conditions. The mechanism of photophysical reductive sintering upon irradiation using a 514.5 nm continuous-wave (CW) laser on NiO NP thin films has been studied through modulating the laser power density and illumination time. Protons produced due to high-temperature decomposition of the solvent present in the NiO NP ink, oxygen vacancies in the NiO NPs, and electronic excitation in the NiO NPs by laser irradiation all affect the early stage of the reductive sintering process. Once NiO NPs are reduced by laser irradiation to Ni, they begin to coalesce, forming a conducting material. In situ optical and electrical measurements during the reductive sintering process take advantage of the distinct differences between the oxide and the metallic phases to monitor the transient evolution of the process. We observe four regimes: oxidation, reduction, sintering, and reoxidation. A characteristic time scale is assigned to each regime.

Laser-Induced Reductive Sintering of Nickel Oxide Nanoparticles under Ambient Conditions

KAUST Repository

Paeng, Dongwoo

2015-03-19

© 2015 American Chemical Society. This work is concerned with the kinetics of laser-induced reductive sintering of nonstoichiometric crystalline nickel oxide (NiO) nanoparticles (NPs) under ambient conditions. The mechanism of photophysical reductive sintering upon irradiation using a 514.5 nm continuous-wave (CW) laser on NiO NP thin films has been studied through modulating the laser power density and illumination time. Protons produced due to high-temperature decomposition of the solvent present in the NiO NP ink, oxygen vacancies in the NiO NPs, and electronic excitation in the NiO NPs by laser irradiation all affect the early stage of the reductive sintering process. Once NiO NPs are reduced by laser irradiation to Ni, they begin to coalesce, forming a conducting material. In situ optical and electrical measurements during the reductive sintering process take advantage of the distinct differences between the oxide and the metallic phases to monitor the transient evolution of the process. We observe four regimes: oxidation, reduction, sintering, and reoxidation. A characteristic time scale is assigned to each regime.

How Pt nanoparticles affect TiO2-induced gas-phase photocatalytic oxidation reactions

NARCIS (Netherlands)

Fraters, B.D.; Amrollahi Buky, Rezvaneh; Mul, Guido

2015-01-01

The effect of Pt nanoparticles on the gas-phase photocatalytic oxidation activity of TiO2 is shown to be largely dependent on the molecular functionality of the substrate. We demonstrate that Pt nanoparticles decrease rates in photocatalytic oxidation of propane, whereas a strong beneficial effect

Nanotoxicology of Metal Oxide Nanoparticles

Directory of Open Access Journals (Sweden)

Amedea B. Seabra

2015-06-01

Full Text Available This review discusses recent advances in the synthesis, characterization and toxicity of metal oxide nanoparticles obtained mainly through biogenic (green processes. The in vitro and in vivo toxicities of these oxides are discussed including a consideration of the factors important for safe use of these nanomaterials. The toxicities of different metal oxide nanoparticles are compared. The importance of biogenic synthesized metal oxide nanoparticles has been increasing in recent years; however, more studies aimed at better characterizing the potent toxicity of these nanoparticles are still necessary for nanosafely considerations and environmental perspectives. In this context, this review aims to inspire new research in the design of green approaches to obtain metal oxide nanoparticles for biomedical and technological applications and to highlight the critical need to fully investigate the nanotoxicity of these particles.

Gentamicin coated iron oxide nanoparticles as novel antibacterial agents

Science.gov (United States)

Bhattacharya, Proma; Neogi, Sudarsan

2017-09-01

Applications of different types of magnetic nanoparticles for biomedical purposes started a long time back. The concept of surface functionalization of the iron oxide nanoparticles with antibiotics is a novel technique which paves the path for further application of these nanoparticles by virtue of their property of superparamagnetism. In this paper, we have synthesized novel iron oxide nanoparticles surface functionalized with Gentamicin. The average size of the particles, concluded from the HR-TEM images, came to be around 14 nm and 10 nm for unmodified and modified nanoparticles, respectively. The magnetization curve M(H) obtained for these nanoparticles are typical of superparamagnetic nature and having almost zero values of coercivity and remanance. The release properties of the drug coated nanoparticles were studied; obtaining an S shaped profile, indicating the initial burst effect followed by gradual sustained release. In vitro investigations against various gram positive and gram negative strains viz Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis indicated significant antibacterial efficiency of the drug-nanoparticle conjugate. The MIC values indicated that a small amount like 0.2 mg ml-1 of drug capped particles induce about 98% bacterial death. The novelty of the work lies in the drug capping of the nanoparticles, which retains the superparamagnetic nature of the iron oxide nanoparticles and the medical properties of the drug simultaneously, which is found to extremely blood compatible.

Altering the structure and properties of iron oxide nanoparticles and graphene oxide/iron oxide composites by urea

Energy Technology Data Exchange (ETDEWEB)

Naghdi, Samira [Physics department, Bu-Ali Sina University, 65174 Hamedan (Iran, Islamic Republic of); Department of Mechanical Engineering, College of Engineering, Kyung Hee University, 446-701 Yongin (Korea, Republic of); Rhee, Kyong Yop, E-mail: rheeky@khu.ac.kr [Department of Mechanical Engineering, College of Engineering, Kyung Hee University, 446-701 Yongin (Korea, Republic of); Jaleh, Babak [Physics department, Bu-Ali Sina University, 65174 Hamedan (Iran, Islamic Republic of); Park, Soo Jin [Chemistry, Colloge of Natural Science, Inha University, 402-751 Incheon (Korea, Republic of)

2016-02-28

Graphical abstract: - Highlights: • Iron oxide (Fe{sub 2}O{sub 3}) nanoparticles were directly grown on graphene oxide (GO) using a facile microwave assistant method. • The effect of urea concentration on Fe{sub 2}O{sub 3} nanoparticles and GO/Fe{sub 2}O{sub 3} composite was examined. • Increasing urea concentration altered the morphology and decreased the particle size. • The increased concentration of urea induced a larger surface area with more active sites in the Fe{sub 2}O{sub 3} nanoparticles. • The increase in urea concentration led to decreased thermal stability of the Fe{sub 2}O{sub 3} nanoparticles. - Abstract: Iron oxide (Fe{sub 2}O{sub 3}) nanoparticles were grown on graphene oxide (GO) using a simple microwave-assisted method. The effects of urea concentration on Fe{sub 2}O{sub 3} nanoparticles and GO/Fe{sub 2}O{sub 3} composite were examined. The as-prepared samples were characterized using X-ray powder diffraction, Raman spectroscopy, and transmission electron microscopy. The Fe{sub 2}O{sub 3} nanoparticles were uniformly developed on GO sheets. The results showed that urea affects both Fe{sub 2}O{sub 3} morphology and particle size. In the absence of urea, the Fe{sub 2}O{sub 3} nanostructures exhibited a rod-like morphology. However, increasing urea concentration altered the morphology and decreased the particle size. The Raman results of GO/Fe{sub 2}O{sub 3} showed that the intensity ratio of D band to G band (I{sub D}/I{sub G}) was decreased by addition of urea, indicating that urea can preserve the GO sheets during synthesis of the composite from exposing more defects. The surface area and thermal stability of GO/Fe{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} were compared using the Brunauer–Emmett–Teller method and thermal gravimetric analysis, respectively. The results showed that the increased concentration of urea induced a larger surface area with more active sites in the Fe{sub 2}O{sub 3} nanoparticles. However, the increase in urea

Silver nanoparticles induced heat shock protein 70, oxidative stress and apoptosis in Drosophila melanogaster.

Science.gov (United States)

Ahamed, Maqusood; Posgai, Ryan; Gorey, Timothy J; Nielsen, Mark; Hussain, Saber M; Rowe, John J

2010-02-01

Due to the intensive commercial application of silver nanoparticles (Ag NPs), risk assessment of this nanoparticle is of great importance. Our previous in vitro study demonstrated that Ag NPs caused DNA damage and apoptosis in mouse embryonic stem cells and fibroblasts. However, toxicity of Ag NPs in vivo is largely lacking. This study was undertaken to examine the toxic effects of well-characterized polysaccharide coated 10 nm Ag NPs on heat shock stress, oxidative stress, DNA damage and apoptosis in Drosophila melanogaster. Third instar larvae of D. melanogaster were fed a diet of standard cornmeal media mixed with Ag NPs at the concentrations of 50 and 100 microg/ml for 24 and 48 h. Ag NPs up-regulated the expression of heat shock protein 70 and induced oxidative stress in D. melanogaster. Malondialdehyde level, an end product of lipid peroxidation was significantly higher while antioxidant glutathione content was significantly lower in Ag NPs exposed organisms. Activities of antioxidant enzyme superoxide dismutase and catalase were also significantly higher in the organisms exposed to Ag NPs. Furthermore, Ag NPs up-regulated the cell cycle checkpoint p53 and cell signaling protein p38 that are involved in the DNA damage repair pathway. Moreover, activities of caspase-3 and caspase-9, markers of apoptosis were significantly higher in Ag NPs exposed organisms. The results indicate that Ag NPs in D. melanogaster induce heat shock stress, oxidative stress, DNA damage and apoptosis. This study suggests that the organism is stressed and thus warrants more careful assessment of Ag NPs using in vivo models to determine if chronic exposure presents developmental and reproductive toxicity. Copyright 2009 Elsevier Inc. All rights reserved.

Silver nanoparticles induced heat shock protein 70, oxidative stress and apoptosis in Drosophila melanogaster

International Nuclear Information System (INIS)

Ahamed, Maqusood; Posgai, Ryan; Gorey, Timothy J.; Nielsen, Mark; Hussain, Saber M.; Rowe, John J.

2010-01-01

Due to the intensive commercial application of silver nanoparticles (Ag NPs), risk assessment of this nanoparticle is of great importance. Our previous in vitro study demonstrated that Ag NPs caused DNA damage and apoptosis in mouse embryonic stem cells and fibroblasts. However, toxicity of Ag NPs in vivo is largely lacking. This study was undertaken to examine the toxic effects of well-characterized polysaccharide coated 10 nm Ag NPs on heat shock stress, oxidative stress, DNA damage and apoptosis in Drosophila melanogaster. Third instar larvae of D. melanogaster were fed a diet of standard cornmeal media mixed with Ag NPs at the concentrations of 50 and 100 μg/ml for 24 and 48 h. Ag NPs up-regulated the expression of heat shock protein 70 and induced oxidative stress in D. melanogaster. Malondialdehyde level, an end product of lipid peroxidation was significantly higher while antioxidant glutathione content was significantly lower in Ag NPs exposed organisms. Activities of antioxidant enzyme superoxide dismutase and catalase were also significantly higher in the organisms exposed to Ag NPs. Furthermore, Ag NPs up-regulated the cell cycle checkpoint p53 and cell signaling protein p38 that are involved in the DNA damage repair pathway. Moreover, activities of caspase-3 and caspase-9, markers of apoptosis were significantly higher in Ag NPs exposed organisms. The results indicate that Ag NPs in D. melanogaster induce heat shock stress, oxidative stress, DNA damage and apoptosis. This study suggests that the organism is stressed and thus warrants more careful assessment of Ag NPs using in vivo models to determine if chronic exposure presents developmental and reproductive toxicity.

Cerium oxide and platinum nanoparticles protect cells from oxidant-mediated apoptosis

International Nuclear Information System (INIS)

Clark, Andrea; Zhu Aiping; Sun Kai; Petty, Howard R.

2011-01-01

Catalytic nanoparticles represent a potential clinical approach to replace or correct aberrant enzymatic activities in patients. Several diseases, including many blinding eye diseases, are promoted by excessive oxidant stress due to reactive oxygen species (ROS). Cerium oxide and platinum nanoparticles represent two potentially therapeutic nanoparticles that de-toxify ROS. In the present study, we directly compare these two classes of catalytic nanoparticles. Cerium oxide and platinum nanoparticles were found to be 16 ± 2.4 and 1.9 ± 0.2 nm in diameter, respectively. Using surface plasmon-enhanced microscopy, we find that these nanoparticles associate with cells. Furthermore, cerium oxide and platinum nanoparticles demonstrated superoxide dismutase catalytic activity, but did not promote hemolytic or cytolytic pathways in living cells. Importantly, both cerium oxide and platinum nanoparticles reduce oxidant-mediated apoptosis in target cells as judged by the activation of caspase 3. The ability to diminish apoptosis may contribute to maintaining healthy tissues.

Development of HSPA1A promoter-driven luciferase reporter gene assays in human cells for assessing the oxidative damage induced by silver nanoparticles

International Nuclear Information System (INIS)

Xin, Lili; Wang, Jianshu; Zhang, Leshuai W.; Che, Bizhong; Dong, Guangzhu; Fan, Guoqiang; Cheng, Kaiming

2016-01-01

The exponential increase in the total number of engineered nanoparticles in consumer products requires novel tools for rapid and cost-effective toxicology screening. In order to assess the oxidative damage induced by nanoparticles, toxicity test systems based on a human HSPA1A promoter-driven luciferase reporter in HepG2, LO2, A549, and HBE cells were established. After treated with heat shock and a group of silver nanoparticles (AgNPs) with different primary particle sizes, the cell viability, oxidative damage, and luciferase activity were determined. The time-dependent Ag + ions release from AgNPs in cell medium was also evaluated. Our results showed that heat shock produced a strong time-dependent induction of relative luciferase activity in the four luciferase reporter cells. Surprisingly, at 4 h of recovery, the relative luciferase activity was > 98 × the control level in HepG2-luciferase cells. Exposure to different sizes of AgNPs resulted in activation of the HSPA1A promoter in a dose-dependent manner, even at low cytotoxic or non-cytotoxic doses. The smaller (5 nm) AgNPs were more potent in luciferase induction than the larger (50 and 75 nm) AgNPs. These results were generally in accordance with the oxidative damage indicated by malondialdehyde concentration, reactive oxygen species induction and glutathione depletion, and Ag + ions release in cell medium. Compared with the other three luciferase reporter cells, the luciferase signal in HepG2-luciferase cells is obviously more sensitive and stable. We conclude that the luciferase reporter cells, especially the HepG2-luciferase cells, could provide a valuable tool for rapid screening of the oxidative damage induced by AgNPs. - Highlights: • We established the stable HSPA1A promoter-driven luciferase reporter cells. • Silver nanoparticles induced dose-dependent increases in luciferase activity. • HSPA1A promoter activity is a sensitive and responsive indicator of oxidative stress. • HepG2-luciferase

Development of HSPA1A promoter-driven luciferase reporter gene assays in human cells for assessing the oxidative damage induced by silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Xin, Lili, E-mail: llxin@suda.edu.cn [School of Public Health, Medical College of Soochow University, 199 Renai Road, Suzhou 215123, Jiangsu (China); Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, School of Public Health, Soochow University, Suzhou 215123 (China); Wang, Jianshu [Suzhou Center for Disease Prevention and Control, 72 Sanxiang Road, Suzhou, Jiangsu (China); Zhang, Leshuai W. [School of Radiation Medicine and Protection & School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 (China); Che, Bizhong; Dong, Guangzhu [School of Public Health, Medical College of Soochow University, 199 Renai Road, Suzhou 215123, Jiangsu (China); Fan, Guoqiang; Cheng, Kaiming [Suzhou Industrial Park Centers for Disease Control and Prevention, 58 Suqian Road, Suzhou, Jiangsu (China)

2016-08-01

The exponential increase in the total number of engineered nanoparticles in consumer products requires novel tools for rapid and cost-effective toxicology screening. In order to assess the oxidative damage induced by nanoparticles, toxicity test systems based on a human HSPA1A promoter-driven luciferase reporter in HepG2, LO2, A549, and HBE cells were established. After treated with heat shock and a group of silver nanoparticles (AgNPs) with different primary particle sizes, the cell viability, oxidative damage, and luciferase activity were determined. The time-dependent Ag{sup +} ions release from AgNPs in cell medium was also evaluated. Our results showed that heat shock produced a strong time-dependent induction of relative luciferase activity in the four luciferase reporter cells. Surprisingly, at 4 h of recovery, the relative luciferase activity was > 98 × the control level in HepG2-luciferase cells. Exposure to different sizes of AgNPs resulted in activation of the HSPA1A promoter in a dose-dependent manner, even at low cytotoxic or non-cytotoxic doses. The smaller (5 nm) AgNPs were more potent in luciferase induction than the larger (50 and 75 nm) AgNPs. These results were generally in accordance with the oxidative damage indicated by malondialdehyde concentration, reactive oxygen species induction and glutathione depletion, and Ag{sup +} ions release in cell medium. Compared with the other three luciferase reporter cells, the luciferase signal in HepG2-luciferase cells is obviously more sensitive and stable. We conclude that the luciferase reporter cells, especially the HepG2-luciferase cells, could provide a valuable tool for rapid screening of the oxidative damage induced by AgNPs. - Highlights: • We established the stable HSPA1A promoter-driven luciferase reporter cells. • Silver nanoparticles induced dose-dependent increases in luciferase activity. • HSPA1A promoter activity is a sensitive and responsive indicator of oxidative stress. • HepG2

Green Synthesized Zinc Oxide (ZnO) Nanoparticles Induce Oxidative Stress and DNA Damage in Lathyrus sativus L. Root Bioassay System.

Science.gov (United States)

Panda, Kamal K; Golari, Dambaru; Venugopal, A; Achary, V Mohan M; Phaomei, Ganngam; Parinandi, Narasimham L; Sahu, Hrushi K; Panda, Brahma B

2017-05-18

Zinc oxide nanoparticles (ZnONP-GS) were synthesised from the precursor zinc acetate (Zn(CH₃COO)₂) through the green route using the milky latex from milk weed ( Calotropis gigantea L. R. Br) by alkaline precipitation. Formation of the ZnONP-GS was monitored by UV-visible spectroscopy followed by characterization and confirmation by energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Both the ZnONP-GS and the commercially available ZnONP-S (Sigma-Aldrich) and cationic Zn 2+ from Zn(CH₃COO)₂ were tested in a dose range of 0-100 mg·L -1 for their potency (i) to induce oxidative stress as measured by the generation reactive oxygen species (ROS: O₂ •- , H₂O₂ and • OH), cell death, and lipid peroxidation; (ii) to modulate the activities of antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX); and (iii) to cause DNA damage as determined by Comet assay in Lathyrus sativus L. root bioassay system. Antioxidants such as Tiron and dimethylthiourea significantly attenuated the ZnONP-induced oxidative and DNA damage, suggesting the involvement of ROS therein. Our study demonstrated that both ZnONP-GS and ZnONP-S induced oxidative stress and DNA damage to a similar extent but were significantly less potent than Zn 2+ alone.

Probing the diffusion of vacuum ultraviolet ({lambda} = 172 nm) induced oxidants by nanoparticles immobilization

Energy Technology Data Exchange (ETDEWEB)

Khatri, Om P.; Hatanaka, Takeshi; Murase, Kuniaki [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Sugimura, Hiroyuki, E-mail: hiroyuki.sugimura@materials.mbox.media.kyoto-u.ac.jp [Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan)

2009-09-30

Vacuum ultraviolet (VUV, {lambda} = 172 nm) patterning of alkyl monolayer on silicon surface has been demonstrated with emphasis on the diffusion of VUV induced oxygen-derived active species, which are accountable for the pattern broadening. The VUV photons photo-dissociates the atmospheric oxygen and water molecules into the oxygen-derived active species (oxidants). These oxidants photo-oxidize the hexadecyl (HD) monolayer in VUV irradiated regions (Khatri et al., Langmuir. 24 (2008) 12077), as well as the little concentration of oxidants diffuses towards the masked areas. In this study, we performed VUV patterning at a vacuum pressure of 10 Pa to track the diffusion pathways for the oxidants with help of gold nanoparticles (AuNPs; {phi} = 10 nm) immobilization. At VUV irradiated sites AuNPs are found as uniformly distributed, but adjacent to the pattern boundary we observed quasi-linear arrays of AuNPs, which are determined by diffusion pathways of the oxidants. The diffusion of oxidants plays vital role in pattern broadening. The site selective anchoring of AuNPs demonstrates the utility of VUV photons for the construction of functional materials with microstructural architecture.

Radiation dose rate affects the radiosensitization of MCF-7 and HeLa cell lines to X-rays induced by dextran-coated iron oxide nanoparticles.

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Khoshgard, Karim; Kiani, Parvaneh; Haghparast, Abbas; Hosseinzadeh, Leila; Eivazi, Mohammad Taghi

2017-08-01

The aim of radiotherapy is to deliver lethal damage to cancerous tissue while preserving adjacent normal tissues. Radiation absorbed dose of the tumoral cells can increase when high atomic nanoparticles are present in them during irradiation. Also, the dose rate is an important aspect in radiation effects that determines the biological results of a given dose. This in vitro study investigated the dose-rate effect on the induced radiosensitivity by dextran-coated iron oxide in cancer cells. HeLa and MCF-7 cells were cultured in vitro and incubated with different concentrations of dextran-coated iron oxide nanoparticles. They were then irradiated with 6 MV photons at dose rates of 43, 185 and 370 cGy/min. The MTT test was used to obtain the cells' survival after 48 h of irradiations. Incubating the cells with the nanoparticles at concentrations of 10, 40 and 80 μg/ml showed no significant cytotoxicity effect. Dextran-coated iron oxide nanoparticles showed more radiosensitivity effect by increasing the dose rate and nanoparticles concentration. Radiosensitization enhancement factors of MCF-7 and HeLa cells at a dose-rate of 370 cGy/min and nanoparticles' concentration of 80 μg/ml were 1.21 ± 0.06 and 1.19 ± 0.04, respectively. Increasing the dose rate of 6 MV photons irradiation in MCF-7 and HeLa cells increases the radiosensitization induced by the dextran-coated iron nanoparticles in these cells.

In vitro toxicity of zinc oxide nanoparticles: a review

International Nuclear Information System (INIS)

Pandurangan, Muthuraman; Kim, Doo Hwan

2015-01-01

The toxic effect of ZnO nanoparticles is due to their solubility. ZnO nanoparticles dissolve in the extracellular region, which in turn increases the intracellular [Zn 2+ ] level. The mechanism for increased intracellular [Zn 2+ ] level and ZnO nanoparticles dissolution in the medium is still unclear. Cytotoxicity, increased oxidative stress, increased intracellular [Ca 2+ ] level, decreased mitochondrial membrane potential, and interleukin-8 productions occur in the BEAS-2B bronchial epithelial cells and A549 alveolar adenocarcinoma cells following the exposure of ZnO nanoparticles. Confluent C2C12 cells are more resistant to ZnO nanoparticles compared to the sparse monolayer. Loss of 3T3-L1 cell viability, membrane leakage, and morphological changes occurs due to exposure of ZnO nanoparticles. ZnO nanoparticle induces cytotoxicity and mitochondrial dysfunction in RKO colon carcinoma cells. The occurrence of apoptosis, increased ROS level, reduced mitochondrial activity and formation of tubular intracellular structures are reported following exposure of ZnO nanoparticles in skin cells. Macrophages, monocytes, and dendritic cells are affected by ZnO nanoparticles. In addition, genotoxicity is also induced. The present review summarizes the literature on in vitro toxicity of ZnO nanoparticles (10–100 nm) on various cell lines

In vitro toxicity of zinc oxide nanoparticles: a review

Energy Technology Data Exchange (ETDEWEB)

Pandurangan, Muthuraman; Kim, Doo Hwan, E-mail: frenzram1980@gmail.com [Konkuk University, Department of Bioresources and Food Sciences (Korea, Republic of)

2015-03-15

The toxic effect of ZnO nanoparticles is due to their solubility. ZnO nanoparticles dissolve in the extracellular region, which in turn increases the intracellular [Zn{sup 2+}] level. The mechanism for increased intracellular [Zn{sup 2+}] level and ZnO nanoparticles dissolution in the medium is still unclear. Cytotoxicity, increased oxidative stress, increased intracellular [Ca{sup 2+}] level, decreased mitochondrial membrane potential, and interleukin-8 productions occur in the BEAS-2B bronchial epithelial cells and A549 alveolar adenocarcinoma cells following the exposure of ZnO nanoparticles. Confluent C2C12 cells are more resistant to ZnO nanoparticles compared to the sparse monolayer. Loss of 3T3-L1 cell viability, membrane leakage, and morphological changes occurs due to exposure of ZnO nanoparticles. ZnO nanoparticle induces cytotoxicity and mitochondrial dysfunction in RKO colon carcinoma cells. The occurrence of apoptosis, increased ROS level, reduced mitochondrial activity and formation of tubular intracellular structures are reported following exposure of ZnO nanoparticles in skin cells. Macrophages, monocytes, and dendritic cells are affected by ZnO nanoparticles. In addition, genotoxicity is also induced. The present review summarizes the literature on in vitro toxicity of ZnO nanoparticles (10–100 nm) on various cell lines.

Pure and multi metal oxide nanoparticles: synthesis, antibacterial and cytotoxic properties.

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Stankic, Slavica; Suman, Sneha; Haque, Francia; Vidic, Jasmina

2016-10-24

Th antibacterial activity of metal oxide nanoparticles has received marked global attention as they can be specifically synthesized to exhibit significant toxicity to bacteria. The importance of their application as antibacterial agents is evident keeping in mind the limited range and effectiveness of antibiotics, on one hand, and the plethora of metal oxides, on the other, along with the propensity of nanoparticles to induce resistance being much lower than that of antibiotics. Effective inhibition against a wide range of bacteria is well known for several nano oxides consisting of one metal (Fe 3 O 4 , TiO 2 , CuO, ZnO), whereas, research in the field of multi-metal oxides still demands extensive exploration. This is understandable given that the relationship between physicochemical properties and biological activity seems to be complex and difficult to generalize even for metal oxide nanoparticles consisting of only one metal component. Also, despite the broad scope that metal oxide nanoparticles have as antibacterial agents, there arise problems in practical applications taking into account the cytotoxic effects. In this respect, the consideration of polymetallic oxides for biological applications becomes even greater since these can provide synergetic effects and unify the best physicochemical properties of their components. For instance, strong antibacterial efficiency specific of one metal oxide can be complemented by non-cytotoxicity of another. This review presents the main methods and technological advances in fabrication of nanostructured metal oxides with a particular emphasis to multi-metal oxide nanoparticles, their antibacterial effects and cytotoxicity.

Pure and multi metal oxide nanoparticles: synthesis, antibacterial and cytotoxic properties

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Slavica Stankic

2016-10-01

Full Text Available Abstract Th antibacterial activity of metal oxide nanoparticles has received marked global attention as they can be specifically synthesized to exhibit significant toxicity to bacteria. The importance of their application as antibacterial agents is evident keeping in mind the limited range and effectiveness of antibiotics, on one hand, and the plethora of metal oxides, on the other, along with the propensity of nanoparticles to induce resistance being much lower than that of antibiotics. Effective inhibition against a wide range of bacteria is well known for several nano oxides consisting of one metal (Fe3O4, TiO2, CuO, ZnO, whereas, research in the field of multi-metal oxides still demands extensive exploration. This is understandable given that the relationship between physicochemical properties and biological activity seems to be complex and difficult to generalize even for metal oxide nanoparticles consisting of only one metal component. Also, despite the broad scope that metal oxide nanoparticles have as antibacterial agents, there arise problems in practical applications taking into account the cytotoxic effects. In this respect, the consideration of polymetallic oxides for biological applications becomes even greater since these can provide synergetic effects and unify the best physicochemical properties of their components. For instance, strong antibacterial efficiency specific of one metal oxide can be complemented by non-cytotoxicity of another. This review presents the main methods and technological advances in fabrication of nanostructured metal oxides with a particular emphasis to multi-metal oxide nanoparticles, their antibacterial effects and cytotoxicity.

Evaluation of the role of oxidative stress, inflammation and apoptosis in the pulmonary and the hepatic toxicity induced by cerium oxide nanoparticles following intratracheal instillation in male Sprague-Dawley rats

Science.gov (United States)

Nalabotu, Siva Krishna

levels, reduced albumin levels, a diminished sodium-potassium ratio and decreased serum triglyceride levels. Consistent with these data, rats exposed to CeO2 nanoparticles also exhibited reductions in liver weight and dose dependent hydropic degeneration, hepatocyte enlargement, sinusoidal dilatation and the accumulation of granular material in the hepatocytes. In a follow-up study, we next examined if CeO2 deposition in the liver is characterized by increased oxidative stress and apoptosis. Our data demonstrate that increased cerium in the liver is associated with increased oxidative stress and apoptosis as assessed from hydroethidium staining, the analysis of lipid peroxidation, and TUNEL staining. In addition, increased cerium concentration in the liver was associated with an increased Bax to Bcl-2 ratio, elevated caspase-9 and elevated caspase-3 protein levels. Taken together, these data suggest that exposure to CeO 2 nanoparticles is associated with increased oxidative stress and cellular apoptosis in the lungs. It is also evident that CeO2 nanoparticles can translocate to liver and induce hepatic damage. The hepatic damage induced by CeO2 nanoparticles is associated with increased oxidative stress and apoptosis in the liver.

Green Synthesized Zinc Oxide (ZnO Nanoparticles Induce Oxidative Stress and DNA Damage in Lathyrus sativus L. Root Bioassay System

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Kamal K. Panda

2017-05-01

Full Text Available Zinc oxide nanoparticles (ZnONP-GS were synthesised from the precursor zinc acetate (Zn(CH3COO2 through the green route using the milky latex from milk weed (Calotropis gigantea L. R. Br by alkaline precipitation. Formation of the ZnONP-GS was monitored by UV-visible spectroscopy followed by characterization and confirmation by energy-dispersive X-ray spectroscopy (EDX, transmission electron microscopy (TEM, and X-ray diffraction (XRD. Both the ZnONP-GS and the commercially available ZnONP-S (Sigma-Aldrich and cationic Zn2+ from Zn(CH3COO2 were tested in a dose range of 0–100 mg·L−1 for their potency (i to induce oxidative stress as measured by the generation reactive oxygen species (ROS: O2•−, H2O2 and •OH, cell death, and lipid peroxidation; (ii to modulate the activities of antioxidant enzymes: catalase (CAT, superoxide dismutase (SOD, guaiacol peroxidase (GPX, and ascorbate peroxidase (APX; and (iii to cause DNA damage as determined by Comet assay in Lathyrus sativus L. root bioassay system. Antioxidants such as Tiron and dimethylthiourea significantly attenuated the ZnONP-induced oxidative and DNA damage, suggesting the involvement of ROS therein. Our study demonstrated that both ZnONP-GS and ZnONP-S induced oxidative stress and DNA damage to a similar extent but were significantly less potent than Zn2+ alone.

Mechanisms of carbon nanotube-induced toxicity: Focus on oxidative stress

Energy Technology Data Exchange (ETDEWEB)

Shvedova, Anna A., E-mail: ats1@cdc.gov [Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, University of Rome “Tor Vergata”, Rome (Italy); Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV, University of Rome “Tor Vergata”, Rome (Italy); Pietroiusti, Antonio [Department of Biopathology, University of Rome “Tor Vergata”, Rome (Italy); Fadeel, Bengt [Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA (United States); Kagan, Valerian E. [Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA (United States)

2012-06-01

Nanotechnologies are emerging as highly promising technologies in many sectors in the society. However, the increasing use of engineered nanomaterials also raises concerns about inadvertent exposure to these materials and the potential for adverse effects on human health and the environment. Despite several years of intensive investigations, a common paradigm for the understanding of nanoparticle-induced toxicity remains to be firmly established. Here, the so-called oxidative stress paradigm is scrutinized. Does oxidative stress represent a secondary event resulting inevitably from disruption of biochemical processes and the demise of the cell, or a specific, non-random event that plays a role in the induction of cellular damage e.g. apoptosis? The answer to this question will have important ramifications for the development of strategies for mitigation of adverse effects of nanoparticles. Recent examples of global lipidomics studies of nanoparticle-induced tissue damage are discussed along with proteomics and transcriptomics approaches to achieve a comprehensive understanding of the complex and interrelated molecular changes in cells and tissues exposed to nanoparticles. We also discuss instances of non-oxidative stress-mediated cellular damage resulting from direct physical interference of nanomaterials with cellular structures. -- Highlights: ► CNT induced non-random oxidative stress associated with apoptosis. ► Non-oxidative mechanisms for cellular toxicity of carbon nanotubes. ► Biodegradation of CNT by cells of innate immune system. ► “Omics”-based biomarkers of CNT exposures.

Mechanisms of carbon nanotube-induced toxicity: Focus on oxidative stress

International Nuclear Information System (INIS)

Shvedova, Anna A.; Pietroiusti, Antonio; Fadeel, Bengt; Kagan, Valerian E.

2012-01-01

Nanotechnologies are emerging as highly promising technologies in many sectors in the society. However, the increasing use of engineered nanomaterials also raises concerns about inadvertent exposure to these materials and the potential for adverse effects on human health and the environment. Despite several years of intensive investigations, a common paradigm for the understanding of nanoparticle-induced toxicity remains to be firmly established. Here, the so-called oxidative stress paradigm is scrutinized. Does oxidative stress represent a secondary event resulting inevitably from disruption of biochemical processes and the demise of the cell, or a specific, non-random event that plays a role in the induction of cellular damage e.g. apoptosis? The answer to this question will have important ramifications for the development of strategies for mitigation of adverse effects of nanoparticles. Recent examples of global lipidomics studies of nanoparticle-induced tissue damage are discussed along with proteomics and transcriptomics approaches to achieve a comprehensive understanding of the complex and interrelated molecular changes in cells and tissues exposed to nanoparticles. We also discuss instances of non-oxidative stress-mediated cellular damage resulting from direct physical interference of nanomaterials with cellular structures. -- Highlights: ► CNT induced non-random oxidative stress associated with apoptosis. ► Non-oxidative mechanisms for cellular toxicity of carbon nanotubes. ► Biodegradation of CNT by cells of innate immune system. ► “Omics”-based biomarkers of CNT exposures.

HRTEM Study of Oxide Nanoparticles in K3-ODS Ferritic Steel Developed for Radiation Tolerance

Energy Technology Data Exchange (ETDEWEB)

Hsiung, L; Fluss, M; Tumey, S; Kuntz, J; El-Dasher, B; Wall, M; Choi, W; Kimura, A; Willaime, F; Serruys, Y

2009-11-02

Crystal and interfacial structures of oxide nanoparticles and radiation damage in 16Cr-4.5Al-0.3Ti-2W-0.37 Y{sub 2}O{sub 3} ODS ferritic steel have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. Oxide nanoparticles with a complex-oxide core and an amorphous shell were frequently observed. The crystal structure of complex-oxide core is identified to be mainly monoclinic Y{sub 4}Al{sub 2}O{sub 9} (YAM) oxide compound. Orientation relationships between the oxide and the matrix are found to be dependent on the particle size. Large particles (> 20 nm) tend to be incoherent and have a spherical shape, whereas small particles (< 10 nm) tend to be coherent or semi-coherent and have a faceted interface. The observations of partially amorphous nanoparticles and multiple crystalline domains formed within a nanoparticle lead us to propose a three-stage mechanism to rationalize the formation of oxide nanoparticles containing core/shell structures in as-fabricated ODS steels. Effects of nanoparticle size and density on cavity formation induced by (Fe{sup 8+} + He{sup +}) dual-beam irradiation are briefly addressed.

Evaluation of Antiproliferative Potential of Cerium Oxide Nanoparticles on HeLa Human Cervical Tumor Cell

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Zoriţa Diaconeasa

2015-05-01

Full Text Available Cerium oxide nanoparticles (CeO2 nanoparticles as nanomaterials have promising biomedical applications. In this paper, the cytotoxicity induced by CONPs human cervical tumor cells was investigated. Cerium oxide nanoparticles were synthesized using the precipitation method. The nanoparticles were found to inhibit the proliferation of HeLa human cervical tumor cells in a dose dependent manner but did not showed to be cytotoxic as analyzed by MTT assay. The administrated treatment decreased the HeLa cell viability cells from 100% to 65% at the dose of 100 μg/mL.

Comparison of the Pulmonary Oxidative Stress Caused by Intratracheal Instillation and Inhalation of NiO Nanoparticles when Equivalent Amounts of NiO Are Retained in the Lung

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Masanori Horie

2016-01-01

Full Text Available NiO nanoparticles were administered to rat lungs via intratracheal instillation or inhalation. During pulmonary toxicity caused by NiO nanoparticles, the induction of oxidative stress is a major factor. Both intratracheal instillation and inhalation of NiO nanoparticles induced pulmonary oxidative stress. The oxidative stress response protein, heme oxygenase-1 (HO-1, was induced by the administration of NiO nanoparticles at both the protein and gene expression level. Additionally, certain oxidative-stress markers in the lung, such as 8-iso-prostaglandin F2α, thioredoxin, and inducible nitric oxide synthase were increased. Furthermore, the concentration of myeloperoxidase (MPO in the lung was also increased by the administration of NiO nanoparticles. When the amount of NiO in the lung is similar, the responses against pulmonary oxidative stress of intratracheal instillation and inhalation are also similar. However, the state of pulmonary oxidative stress in the early phase was different between intratracheal instillation and inhalation, even if the amount of NiO in the lung was similar. Inhalation causes milder oxidative stress than that caused by intratracheal instillation. On evaluation of the nanoparticle-induced pulmonary oxidative stress in the early phase, we should understand the different states of oxidative stress induced by intratracheal instillation and inhalation.

Cerium and yttrium oxide nanoparticles are neuroprotective

International Nuclear Information System (INIS)

Schubert, David; Dargusch, Richard; Raitano, Joan; Chan, S.-W.

2006-01-01

The responses of cells exposed to nanoparticles have been studied with regard to toxicity, but very little attention has been paid to the possibility that some types of particles can protect cells from various forms of lethal stress. It is shown here that nanoparticles composed of cerium oxide or yttrium oxide protect nerve cells from oxidative stress and that the neuroprotection is independent of particle size. The ceria and yttria nanoparticles act as direct antioxidants to limit the amount of reactive oxygen species required to kill the cells. It follows that this group of nanoparticles could be used to modulate oxidative stress in biological systems

Zinc Oxide Nanoparticle Induces Microglial Death by NADPH-Oxidase-Independent Reactive Oxygen Species as well as Energy Depletion.

Science.gov (United States)

Sharma, Anuj Kumar; Singh, Vikas; Gera, Ruchi; Purohit, Mahaveer Prasad; Ghosh, Debabrata

2017-10-01

Zinc oxide nanoparticle (ZnO-NP) is one of the most widely used engineered nanoparticles. Upon exposure, nanoparticle can eventually reach the brain through various routes, interact with different brain cells, and alter their activity. Microglia is the fastest glial cell to respond to any toxic insult. Nanoparticle exposure can activate microglia and induce neuroinflammation. Simultaneous to activation, microglial death can exacerbate the scenario. Therefore, we focused on studying the effect of ZnO-NP on microglia and finding out the pathway involved in the microglial death. The present study showed that the 24 h inhibitory concentration 50 (IC 50 ) of ZnO-NP for microglia is 6.6 μg/ml. Early events following ZnO-NP exposure involved increase in intracellular calcium level as well as reactive oxygen species (ROS). Neither of NADPH oxidase inhibitors, apocynin, (APO) and diphenyleneiodonium chloride (DPIC) were able to reduce the ROS level and rescue microglia from ZnO-NP toxicity. In contrary, N-acetyl cysteine (NAC) showed opposite effect. Exogenous supplementation of superoxide dismutase (SOD) reduced ROS significantly even beyond control level but partially rescued microglial viability. Interestingly, pyruvate supplementation rescued microglia near to control level. Following 10 h of ZnO-NP exposure, intracellular ATP level was measured to be almost 50 % to the control. ZnO-NP-induced ROS as well as ATP depletion both disturbed mitochondrial membrane potential and subsequently triggered the apoptotic pathway. The level of apoptosis-inducing proteins was measured by western blot analysis and found to be upregulated. Taken together, we have deciphered that ZnO-NP induced microglial apoptosis by NADPH oxidase-independent ROS as well as ATP depletion.

Sex-Dependent Depression-Like Behavior Induced by Respiratory Administration of Aluminum Oxide Nanoparticles

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Xin Zhang

2015-12-01

Full Text Available Ultrafine aluminum oxide, which are abundant in ambient and involved occupational environments, are associated with neurobehavioral alterations. However, few studies have focused on the effect of sex differences following exposure to environmental Al2O3 ultrafine particles. In the present study, male and female mice were exposed to Al2O3 nanoparticles (NPs through a respiratory route. Only the female mice showed depression-like behavior. Although no obvious pathological changes were observed in mice brain tissues, the neurotransmitter and voltage-gated ion channel related gene expression, as well as the small molecule metabolites in the cerebral cortex, were differentially modulated between male and female mice. Both mental disorder-involved gene expression levels and metabolomics analysis results strongly suggested that glutamate pathways were implicated in sex differentiation induced by Al2O3 NPs. Results demonstrated the potential mechanism of environmental ultrafine particle-induced depression-like behavior and the importance of sex dimorphism in the toxic research of environmental chemicals.

Increased mobility of metal oxide nanoparticles due to photo and thermal induced disagglomeration.

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Dongxu Zhou

Full Text Available Significant advances have been made on our understanding of the fate and transport of engineered nanomaterials. One unexplored aspect of nanoparticle aggregation is how environmental stimuli such as light exposure and temperature variations affect the mobility of engineered nanoparticles. In this study, TiO(2, ZnO, and CeO(2 were chosen as model materials for investigating the mobility of nanoparticles under three external stimuli: heat, light and sonication. Sunlight and high power sonication were able to partially disagglomerate metal oxide clusters, but primary particles bonded by solid state necks were left intact. A cycle of temperature increase from 25°C to 65°C and then decrease back was found to disagglomerate the compact clusters in the heating phase and reagglomerate them as more open fractal structures during the cooling phase. A fractal model summing the pair-wise DLVO interactions between primary particles within two fractal agglomerates predicts weak attractions on the order of a few kT. Our study shows that common environmental stimuli such as light exposure or temperature variation can disagglomerate nanoparticle clusters and enhance their mobility in open waters. This phenomenon warrants attention since it is likely that metal oxide nanoparticles will experience these natural stimuli during their transport in the environment.

Silver Nanoparticles-graphene Oxide Nanocomposite for Antibacterial Purpose

International Nuclear Information System (INIS)

Chook, S.W.; Chia, C.H.; Sarani Zakaria; Mohd Khan Ayob; Chee, K.L.; Neoh, H.M.; Huang, N.M.

2011-01-01

Graphene oxide (GO) sheets, a single layer of carbon atoms which can be served as substrates for fabricating metallic nanoparticles-GO nano composites, have been used in this study The nanocomposite of silver nanoparticles and graphene oxide were produced via in-situ synthesis and with the aid of chitosan to investigate the formation of silver nanoparticles on the graphene oxide sheets. XRD and UV-Vis studies confirmed the formation of silver nanoparticles on GO sheets, while TEM and FESEM images presented the loading of silver nanoparticles on the GO sheets. The degree of loading and distribution of the silver nanoparticles on the graphene oxide were depended on the procedure during the formation of silver nanoparticles. The nano composites can be potentially used in food packaging and biomedical applications. (author)

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.

Magnetic behavior of iron oxide nanoparticle-biomolecule assembly

International Nuclear Information System (INIS)

Kim, Taegyun; Reis, Lynn; Rajan, Krishna; Shima, Mutsuhiro

2005-01-01

Iron oxide nanoparticles of 8-20 nm in size were investigated as an assembly with biomolecules synthesized in an aqueous solution. The magnetic behavior of the biomolecule-nanoparticles assembly depends sensitively on the morphology and hence the distribution of the nanoparticles, where the dipole coupling between the nanoparticles governs the overall magnetic behavior. In assemblies of iron oxide nanoparticles with trypsin, we observe a formation of unusual self-alignment of nanoparticles within trypsin molecules. In such an assembly structure, the magnetic particles tend to exhibit a lower spin-glass transition temperature than as-synthesized bare iron oxide nanoparticles probably due to reduced interparticle couplings within the molecular matrix. The observed self-alignment of nanoparticles in biomolecules may be a useful approach for directed nanoparticles assembly

Zinc oxide nanoparticles decrease the expression and activity of plasma membrane calcium ATPase, disrupt the intracellular calcium homeostasis in rat retinal ganglion cells.

Science.gov (United States)

Guo, Dadong; Bi, Hongsheng; Wang, Daoguang; Wu, Qiuxin

2013-08-01

Zinc oxide nanoparticle is one of the most important materials with diverse applications. However, it has been reported that zinc oxide nanoparticles are toxic to organisms, and that oxidative stress is often hypothesized to be an important factor in cytotoxicity mediated by zinc oxide nanoparticles. Nevertheless, the mechanism of toxicity of zinc oxide nanoparticles has not been completely understood. In this study, we investigated the cytotoxic effect of zinc oxide nanoparticles and the possible molecular mechanism involved in calcium homeostasis mediated by plasma membrane calcium ATPase in rat retinal ganglion cells. Real-time cell electronic sensing assay showed that zinc oxide nanoparticles could exert cytotoxic effect on rat retinal ganglion cells in a concentration-dependent manner; flow cytometric analysis indicated that zinc oxide nanoparticles could lead to cell damage by inducing the overproduction of reactive oxygen species. Furthermore, zinc oxide nanoparticles could also apparently decrease the expression level and their activity of plasma membrane calcium ATPase, which finally disrupt the intracellular calcium homeostasis and result in cell death. Taken together, zinc oxide nanoparticles could apparently decrease the plasma membrane calcium ATPase expression, inhibit their activity, cause the elevated intracellular calcium ion level and disrupt the intracellular calcium homeostasis. Further, the disrupted calcium homeostasis will trigger mitochondrial dysfunction, generate excessive reactive oxygen species, and finally initiate cell death. Thus, the disrupted calcium homeostasis is involved in the zinc oxide nanoparticle-induced rat retinal ganglion cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

Polyethylene glycol-functionalized poly (Lactic Acid-co-Glycolic Acid and graphene oxide nanoparticles induce pro-inflammatory and apoptotic responses in Candida albicans-infected vaginal epithelial cells.

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R Doug Wagner

Full Text Available Mucous-penetrating nanoparticles consisting of poly lactic acid-co-glycolic acid (PLGA-polyethylene glycol (PEG could improve targeting of microbicidal drugs for sexually transmitted diseases by intravaginal inoculation. Nanoparticles can induce inflammatory responses, which may exacerbate the inflammation that occurs in the vaginal tracts of women with yeast infections. This study evaluated the effects of these drug-delivery nanoparticles on VK2(E6/E7 vaginal epithelial cell proinflammatory responses to Candida albicans yeast infections. Vaginal epithelial cell monolayers were infected with C. albicans and exposed to 100 μg/ml 49.5 nm PLGA-PEG nanospheres or 20 μg/ml 1.1 x 500 nm PEG-functionalized graphene oxide (GO-PEG sheets. The cells were assessed for changes in mRNA and protein expression of inflammation-related genes by RT-qPCR and physiological markers of cell stress using high content analysis and flow cytometry. C. albicans exposure suppressed apoptotic gene expression, but induced oxidative stress in the cells. The nanomaterials induced cytotoxicity and programmed cell death responses alone and with C. albicans. PLGA-PEG nanoparticles induced mRNA expression of apoptosis-related genes and induced poly (ADP-ribose polymerase (PARP cleavage, increased BAX/BCL2 ratios, and chromatin condensation indicative of apoptosis. They also induced autophagy, endoplasmic reticulum stress, and DNA damage. They caused the cells to excrete inflammatory recruitment molecules chemokine (C-X-C motif ligand 1 (CXCL1, interleukin-1α (IL1A, interleukin-1β (IL1B, calprotectin (S100A8, and tumor necrosis factor α (TNF. GO-PEG nanoparticles induced expression of necrosis-related genes and cytotoxicity. They reduced autophagy and endoplasmic reticulum stress, and apoptotic gene expression responses. The results show that stealth nanoparticle drug-delivery vehicles may cause intracellular damage to vaginal epithelial cells by several mechanisms and that

Structural, optical, morphological and dielectric properties of cerium oxide nanoparticles

International Nuclear Information System (INIS)

Prabaharan, Devadoss Mangalam Durai Manoharadoss; Sadaiyandi, Karuppasamy; Mahendran, Manickam; Sagadevan, Suresh

2016-01-01

Cerium oxide (CeO 2 ) nanoparticles were prepared by the precipitation method. The average crystallite size of cerium oxide nanoparticles was calculated from the X-ray diffraction (XRD) pattern and found to be 11 nm. The FT-IR spectrum clearly indicated the strong presence of cerium oxide nanoparticles. Raman spectrum confirmed the cubic nature of the cerium oxide nanoparticles. The Scanning Electron Microscopy (SEM) analysis showed that the nanoparticles agglomerated forming spherical-shaped particles. The Transmission Electron Microscopic (TEM) analysis confirmed the prepared cerium oxide nanoparticles with the particle size being found to be 16 nm. The optical absorption spectrum showed a blue shift by the cerium oxide nanoparticles due to the quantum confinement effect. The dielectric properties of cerium oxide nanoparticles were studied for different frequencies at different temperatures. The dielectric constant and the dielectric loss of the cerium oxide nanoparticles decreased with increase in frequency. The AC electrical conductivity study revealed that the conduction depended on both the frequency and the temperature. (author)

Structural, optical, morphological and dielectric properties of cerium oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Prabaharan, Devadoss Mangalam Durai Manoharadoss [Department of Physics, NPR College of Engineering and Technology, Natham, Dindigul, Tamil Nadu (India); Sadaiyandi, Karuppasamy [Department of Physics, Alagappa Government Arts College, Karaikudi, Sivaganga, Tamil Nadu (India); Mahendran, Manickam [Department of Physics, Thiagarajar College of Engineering, Madurai, Tamil Nadu (India); Sagadevan, Suresh, E-mail: duraiphysics2011@gmail.com [Department of Physics, AMET University (India)

2016-03-15

Cerium oxide (CeO{sub 2}) nanoparticles were prepared by the precipitation method. The average crystallite size of cerium oxide nanoparticles was calculated from the X-ray diffraction (XRD) pattern and found to be 11 nm. The FT-IR spectrum clearly indicated the strong presence of cerium oxide nanoparticles. Raman spectrum confirmed the cubic nature of the cerium oxide nanoparticles. The Scanning Electron Microscopy (SEM) analysis showed that the nanoparticles agglomerated forming spherical-shaped particles. The Transmission Electron Microscopic (TEM) analysis confirmed the prepared cerium oxide nanoparticles with the particle size being found to be 16 nm. The optical absorption spectrum showed a blue shift by the cerium oxide nanoparticles due to the quantum confinement effect. The dielectric properties of cerium oxide nanoparticles were studied for different frequencies at different temperatures. The dielectric constant and the dielectric loss of the cerium oxide nanoparticles decreased with increase in frequency. The AC electrical conductivity study revealed that the conduction depended on both the frequency and the temperature. (author)

Antimicrobial effects of zinc oxide nanoparticles modified with silver

International Nuclear Information System (INIS)

Lopes, Rayssa Souza; Arantes, Tatiane Moraes

2016-01-01

Full text: With the emergence of resistant microbial organisms to multiple antibiotics, different shapes of silver nanoparticles are among the most promising antimicrobial agents that have been developed from nanotechnology. Besides the silver nanoparticles oxide nanoparticles such as zinc oxide (ZnO) is gaining prominence due to its bactericidal properties. [1-3]. Thus, this study aims to develop biomaterials from zinc oxide nanoparticles modified with silver with antimicrobial properties. The ZnO nanoparticles were synthesized by hydrothermal processing by alkaline hydrolysis zinc acetate. Colloidal dispersions of silver nanoparticles were synthesized by the Turkevich method using sodium citrate to reduce silver nitrate at high pH and at 90 °C in the presence of zinc oxide nanoparticles. Both nanoparticles were characterized by X-ray diffraction (XRD), FTIR and Raman spectroscopy and scanning electron microscopy (SEM). The XRD and Raman spectra showed crystalline ZnO colloidal nanoparticles were obtained in the hexagonal phase. XRD measure showed cubic silver diffraction peaks cubic phase confirmed the presence of the silver nanoparticles decorated zinc oxide nanoparticles. SEM images showed ZnO nanoparticles presented a nanorod shapes with length around 80 nm decorated with spherical silver nanoparticles about 20 nm in diameter The results showed that crystalline zinc oxide colloidal nanoparticles with rod-like morphology and uniform decorated with silver spherical nanoparticles size were obtained by hydrothermal synthesis. Results of antibacterial tests indicate that the ZnO/Ag nanoparticles have antibacterial properties against both Staphylococcus aureus and Escherichia coli. The results demonstrated that the ZnO/Ag nanoparticles have potential use as biomaterials in medical/odontological applications. (author)

Antimicrobial effects of zinc oxide nanoparticles modified with silver

Energy Technology Data Exchange (ETDEWEB)

Lopes, Rayssa Souza; Arantes, Tatiane Moraes, E-mail: rayssasouza.net@gmail.com [Universidade Federal de Goias (UFG), Goiania (Brazil)

2016-07-01

Full text: With the emergence of resistant microbial organisms to multiple antibiotics, different shapes of silver nanoparticles are among the most promising antimicrobial agents that have been developed from nanotechnology. Besides the silver nanoparticles oxide nanoparticles such as zinc oxide (ZnO) is gaining prominence due to its bactericidal properties. [1-3]. Thus, this study aims to develop biomaterials from zinc oxide nanoparticles modified with silver with antimicrobial properties. The ZnO nanoparticles were synthesized by hydrothermal processing by alkaline hydrolysis zinc acetate. Colloidal dispersions of silver nanoparticles were synthesized by the Turkevich method using sodium citrate to reduce silver nitrate at high pH and at 90 °C in the presence of zinc oxide nanoparticles. Both nanoparticles were characterized by X-ray diffraction (XRD), FTIR and Raman spectroscopy and scanning electron microscopy (SEM). The XRD and Raman spectra showed crystalline ZnO colloidal nanoparticles were obtained in the hexagonal phase. XRD measure showed cubic silver diffraction peaks cubic phase confirmed the presence of the silver nanoparticles decorated zinc oxide nanoparticles. SEM images showed ZnO nanoparticles presented a nanorod shapes with length around 80 nm decorated with spherical silver nanoparticles about 20 nm in diameter The results showed that crystalline zinc oxide colloidal nanoparticles with rod-like morphology and uniform decorated with silver spherical nanoparticles size were obtained by hydrothermal synthesis. Results of antibacterial tests indicate that the ZnO/Ag nanoparticles have antibacterial properties against both Staphylococcus aureus and Escherichia coli. The results demonstrated that the ZnO/Ag nanoparticles have potential use as biomaterials in medical/odontological applications. (author)

Characterization of coal fly ash nanoparticles and induced oxidative DNA damage in human peripheral blood mononuclear cells

International Nuclear Information System (INIS)

Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A.; Ali, Al-Yousef Sulaiman; Musarrat, Javed

2012-01-01

The nano-sized particles present in coal fly ash (CFA) were characterized through the X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analyses. The XRD data revealed the average crystallite size of the CFA nanoparticles (CFA-NPs) as 14 nm. TEM and SEM imaging demonstrated predominantly spherical and some polymorphic structures in the size range of 11 to 25 nm. The amount of heavy metal associated with CFA particles (μg/g) were determined as Fe (34160.0 ± 1.38), Ni (150.8 ± 0.78), Cu (99.3 ± 0.56) and Cr (64.0 ± 0.86). However, the bioavailability of heavy metals in terms of percent release was in the order as Cr > Ni > Cu > Fe in CFA-dimethyl sulfoxide (DMSO) extract. The comet and cytokinesis blocked micronucleus (CBMN) assays revealed substantial genomic DNA damage in peripheral blood mononuclear (PBMN) cells treated with CFA-NPs in Aq and DMSO extracts. About 1.8 and 3.6 strand breaks per unit of DNA were estimated through alkaline unwinding assay at 1:100 DNA nucleotide/CFA ppm ratios with the Aq and DMSO extracts, respectively. The DNA and mitochondrial damage was invariably greater with CFA-DMSO extract vis-à-vis -Aq extract. Generation of superoxide anions (O 2 • − ) and intracellular reactive oxygen species (ROS) through metal redox-cycling, alteration in mitochondrial potential and 8-oxodG production elucidated CFA-NPs induced oxidative stress as a plausible mechanism for CFA-induced genotoxicity. -- Highlights: ► CFA consists of spherical crystalline nanoparticles in size range of 11–25 nm. ► Alkaline unwinding assay revealed single-strandedness in CFA treated ctDNA. ► CFA nanoparticles exhibited the ability to induce ROS and oxidative DNA damage. ► Comet and CBMN assays revealed DNA and chromosomal breakage in PBMN cells. ► CFA-NPs resulted in mitochondrial membrane damage in PBMN cells.

Characterization of coal fly ash nanoparticles and induced oxidative DNA damage in human peripheral blood mononuclear cells

Energy Technology Data Exchange (ETDEWEB)

Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A. [Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Ali, Al-Yousef Sulaiman [Department of Medical Laboratory Sciences, College of Applied Medical Science, University of Dammam, P.O. Box 1683, Hafr Al Batin-31991 (Saudi Arabia); Musarrat, Javed, E-mail: musarratj1@yahoo.com [Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Department of Agricultural Microbiology, Faculty of Agricultural Sciences, AMU, Aligarh202002 (India)

2012-10-15

The nano-sized particles present in coal fly ash (CFA) were characterized through the X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analyses. The XRD data revealed the average crystallite size of the CFA nanoparticles (CFA-NPs) as 14 nm. TEM and SEM imaging demonstrated predominantly spherical and some polymorphic structures in the size range of 11 to 25 nm. The amount of heavy metal associated with CFA particles ({mu}g/g) were determined as Fe (34160.0 {+-} 1.38), Ni (150.8 {+-} 0.78), Cu (99.3 {+-} 0.56) and Cr (64.0 {+-} 0.86). However, the bioavailability of heavy metals in terms of percent release was in the order as Cr > Ni > Cu > Fe in CFA-dimethyl sulfoxide (DMSO) extract. The comet and cytokinesis blocked micronucleus (CBMN) assays revealed substantial genomic DNA damage in peripheral blood mononuclear (PBMN) cells treated with CFA-NPs in Aq and DMSO extracts. About 1.8 and 3.6 strand breaks per unit of DNA were estimated through alkaline unwinding assay at 1:100 DNA nucleotide/CFA ppm ratios with the Aq and DMSO extracts, respectively. The DNA and mitochondrial damage was invariably greater with CFA-DMSO extract vis-a-vis -Aq extract. Generation of superoxide anions (O{sub 2} Bullet {sup -}) and intracellular reactive oxygen species (ROS) through metal redox-cycling, alteration in mitochondrial potential and 8-oxodG production elucidated CFA-NPs induced oxidative stress as a plausible mechanism for CFA-induced genotoxicity. -- Highlights: Black-Right-Pointing-Pointer CFA consists of spherical crystalline nanoparticles in size range of 11-25 nm. Black-Right-Pointing-Pointer Alkaline unwinding assay revealed single-strandedness in CFA treated ctDNA. Black-Right-Pointing-Pointer CFA nanoparticles exhibited the ability to induce ROS and oxidative DNA damage. Black-Right-Pointing-Pointer Comet and CBMN assays revealed DNA and chromosomal

The role of magnetic iron oxide nanoparticles in the bacterially induced calcium carbonate precipitation.

Science.gov (United States)

Seifan, Mostafa; Ebrahiminezhad, Alireza; Ghasemi, Younes; Samani, Ali Khajeh; Berenjian, Aydin

2018-04-01

Recently, magnetic iron oxide nanoparticles (IONs) have been used to control and modify the characteristics of concrete and mortar. Concrete is one of the most used materials in the world; however, it is susceptible to cracking. Over recent years, a sustainable biotechnological approach has emerged as an alternative approach to conventional techniques to heal the concrete cracks by the incorporation of bacterial cells and nutrients into the concrete matrix. Once cracking occurs, CaCO 3 is induced and the crack is healed. Considering the positive effects of IONs on the concrete properties, the effect of these nanoparticles on bacterial growth and CaCO 3 biosynthesis needs to be evaluated for their possible application in bio self-healing concrete. In the present work, IONs were successfully synthesized and characterized using various techniques. The presence of IONs showed a significant effect on both bacterial growth and CaCO 3 precipitation. The highest bacterial growth was observed in the presence of 150 μg/mL IONs. The highest concentration of induced CaCO 3 (34.54 g/L) was achieved when the bacterial cells were immobilized with 300 μg/mL of IONs. This study provides new data and supports the possibility of using IONs as a new tool in designing the next generation of bio self-healing concrete.

Iron Oxide Nanoparticles Employed as Seeds for the Induction of Microcrystalline Diamond Synthesis

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Resto Oscar

2008-01-01

Full Text Available AbstractIron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. X-ray diffraction, visible, and ultraviolet Raman Spectroscopy, energy-filtered transmission electron microscopy , electron energy-loss spectroscopy, and X-ray photoelectron spectroscopy (XPS were employed to study the carbon bonding nature of the films and to analyze the carbon clustering around the seed nanoparticles leading to diamond synthesis. The results indicate that iron oxide nanoparticles lose the O atoms, becoming thus active C traps that induce the formation of a dense region of trigonally and tetrahedrally bonded carbon around them with the ensuing precipitation of diamond-type bonds that develop into microcrystalline diamond films under chemical vapor deposition conditions. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

Single-cell nanotoxicity assays of superparamagnetic iron oxide nanoparticles.

Science.gov (United States)

Eustaquio, Trisha; Leary, James F

2012-01-01

Properly evaluating the nanotoxicity of nanoparticles involves much more than bulk-cell assays of cell death by necrosis. Cells exposed to nanoparticles may undergo repairable oxidative stress and DNA damage or be induced into apoptosis. Exposure to nanoparticles may cause the cells to alter their proliferation or differentiation or their cell-cell signaling with neighboring cells in a tissue. Nanoparticles are usually more toxic to some cell subpopulations than others, and toxicity often varies with cell cycle. All of these facts dictate that any nanotoxicity assay must be at the single-cell level and must try whenever feasible and reasonable to include many of these other factors. Focusing on one type of quantitative measure of nanotoxicity, we describe flow and scanning image cytometry approaches to measuring nanotoxicity at the single-cell level by using a commonly used assay for distinguishing between necrotic and apoptotic causes of cell death by one type of nanoparticle. Flow cytometry is fast and quantitative, provided that the cells can be prepared into a single-cell suspension for analysis. But when cells cannot be put into suspension without altering nanotoxicity results, or if morphology, attachment, and stain location are important, a scanning image cytometry approach must be used. Both methods are described with application to a particular type of nanoparticle, a superparamagnetic iron oxide nanoparticle (SPION), as an example of how these assays may be applied to the more general problem of determining the effects of nanomaterial exposure to living cells.

Copper oxide nanoparticles induce the transcriptional modulation of oxidative stress-related genes in Arbacia lixula embryos.

Science.gov (United States)

Giannetto, Alessia; Cappello, Tiziana; Oliva, Sabrina; Parrino, Vincenzo; De Marco, Giuseppe; Fasulo, Salvatore; Mauceri, Angela; Maisano, Maria

2018-06-14

Copper oxide nanoparticles (CuO NPs) are widely used in various industrial applications, i.e. semiconductor devices, batteries, solar energy converter, gas sensor, microelectronics, heat transfer fluids, and have been recently recognized as emerging pollutants of increasing concern for human and marine environmental health. Therefore, the toxicity of CuO NPs needs to be thoroughly understood. In this study, we evaluated the potential role of oxidative stress in CuO NP toxicity by exploring the molecular response of Arbacia lixula embryos to three CuO NP concentrations (0.7, 10, 20 ppb) by investigating the transcriptional patterns of oxidative stress-related genes (catalase and superoxide dismutase) and metallothionein, here cloned and characterized for the first time. Time- and concentration-dependent changes in gene expression were detected in A. lixula embryos exposed to CuO NPs, up to pluteus stage (72 h post-fertilization, hpf), indicating that oxidative stress is one of the toxicity mechanisms for CuO NPs. These findings provide new insights into the comprehension of the molecular mechanisms underlying copper nanoparticle toxicity in A. lixula sea urchin and give new tools for monitoring of aquatic areas, thus corroborating the suitability of this embryotoxicity assay for future evaluation of impacted sites. Copyright © 2018 Elsevier B.V. All rights reserved.

Poly(organo phosphazene) nanoparticles surface modified with poly(ethylene oxide).

Science.gov (United States)

Vandorpe, J; Schacht, E; Stolnik, S; Garnett, M C; Davies, M C; Illum, L; Davis, S S

1996-10-05

The use of biodegradable derivatives of poly(organo phosphazenes) for the preparation of nanoparticles and their surface modification with the novel poly(ethylene oxide) derivative of poly(organo phosphazene) has been assessed using a range of in vitro characterization methods. The nanoparticles were produced by the precipitation solvent evaporation method from the derivative co-substituted with phenylalanine and glycine ethyl ester side groups. A reduction in particle size to less than 200 nm was achieved by an increase in pH of the preparation medium. The formation (and colloidal stability) of these nanoparticles seems to be controlled by two opposite effects: attractive hydrophobic interactions between phenylalanine ester groups and electrostatic repulsions arising from the carboxyl groups formed due to (partial) hydrolysis of the ester bond(s) at the high pH of the preparation medium. The poly[(glycine ethyl ester)phosphazene] derivative containing 5000-Da poly(ethylene oxide) as 5% of the side groups was used for the surface modification of nanoparticles. Adsorbed onto the particles, the polymer produced a thick coating layer of approximately 35 nm. The coated nanoparticles exhibited reduced surface negative potential and improved colloidal stability toward electrolyte-induced flocculation, relative to the uncoated system. However, the steric stabilization provided was less effective than that of a Poloxamine 908 coating. This difference in effectiveness of the steric stabilization might indicate that, although both the stabilizing polymers possess a 5000-Da poly(ethylene oxide) moiety, there is a difference in the arrangements of these poly(ethylene oxide) chains at the particle surface. (c) 1996 John Wiley & Sons, Inc.

A sol-gel method to synthesize indium tin oxide nanoparticles

Institute of Scientific and Technical Information of China (English)

Xiuhua Li; Xiujuan xu; Xin Yin; Chunzhong Li; Jianrong Zhang

2011-01-01

Transparent conductive indium tin oxide (ITO) nanoparticles were synthesized by a novel sol-gel method.Granulated indium and tin were dissolved in HNO3 and partially complexed with citric acid.A sol-gel process was induced when tertiary butyl alcohol was added dropwise to the above solution.ITO nanoparticles with an average crystallite size of 18.5 nm and surface area of 32.6 m2/g were obtained after the gel was heat-treated at 700 C.The ITO nanoparticles showed good sinterability,the starting sintering temperature decreased sharply to 900 C,and the 1400 C sintered pellet had a density of 98.1 ％ of theoretical density (TD).

Synthesis and characterization of dextran-coated iron oxide nanoparticles

Science.gov (United States)

Predescu, Andra Mihaela; Matei, Ecaterina; Berbecaru, Andrei Constantin; Pantilimon, Cristian; Drăgan, Claudia; Vidu, Ruxandra; Predescu, Cristian; Kuncser, Victor

2018-03-01

Synthesis and characterization of iron oxide nanoparticles coated with a large molar weight dextran for environmental applications are reported. The first experiments involved the synthesis of iron oxide nanoparticles which were coated with dextran at different concentrations. The synthesis was performed by a co-precipitation technique, while the coating of iron oxide nanoparticles was carried out in solution. The obtained nanoparticles were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectrometry, Fourier transform infrared spectroscopy and superconducting quantum interference device magnetometry. The results demonstrated a successful coating of iron oxide nanoparticles with large molar weight dextran, of which agglomeration tendency depended on the amount of dextran in the coating solution. SEM and TEM observations have shown that the iron oxide nanoparticles are of about 7 nm in size.

Conducting metal oxide and metal nitride nanoparticles

Science.gov (United States)

DiSalvo, Jr., Francis J.; Subban, Chinmayee V.

2017-12-26

Conducting metal oxide and nitride nanoparticles that can be used in fuel cell applications. The metal oxide nanoparticles are comprised of for example, titanium, niobium, tantalum, tungsten and combinations thereof. The metal nitride nanoparticles are comprised of, for example, titanium, niobium, tantalum, tungsten, zirconium, and combinations thereof. The nanoparticles can be sintered to provide conducting porous agglomerates of the nanoparticles which can be used as a catalyst support in fuel cell applications. Further, platinum nanoparticles, for example, can be deposited on the agglomerates to provide a material that can be used as both an anode and a cathode catalyst support in a fuel cell.

Ultrasmall lanthanide oxide nanoparticles for biomedical imaging and therapy

CERN Document Server

Lee, Gang Ho

2014-01-01

Most books discuss general and broad topics regarding molecular imagings. However, Ultrasmall Lanthanide Oxide Nanoparticles for Biomedical Imaging and Therapy, will mainly focus on lanthanide oxide nanoparticles for molecular imaging and therapeutics. Multi-modal imaging capabilities will discussed, along with up-converting FI by using lanthanide oxide nanoparticles. The synthesis will cover polyol synthesis of lanthanide oxide nanoparticles, Surface coatings with biocompatible and hydrophilic ligands will be discussed and TEM images and dynamic light scattering (DLS) patterns will be

Eupafolin nanoparticles protect HaCaT keratinocytes from particulate matter-induced inflammation and oxidative stress

Science.gov (United States)

Lin, Zih-Chan; Lee, Chiang-Wen; Tsai, Ming-Horng; Ko, Horng-Huey; Fang, Jia-You; Chiang, Yao-Chang; Liang, Chan-Jung; Hsu, Lee-Fen; Hu, Stephen Chu-Sung; Yen, Feng-Lin

2016-01-01

Exposure to particulate matter (PM), a major form of air pollution, can induce oxidative stress and inflammation and may lead to many diseases in various organ systems including the skin. Eupafolin, a flavonoid compound derived from Phyla nodiflora, has been previously shown to exhibit various pharmacological activities, including antioxidant and anti-inflammatory effects. Unfortunately, eupafolin is characterized by poor water solubility and skin penetration, which limits its clinical applications. To address these issues, we successfully synthesized a eupafolin nanoparticle delivery system (ENDS). Our findings showed that ENDS could overcome the physicochemical drawbacks of raw eupafolin with respect to water solubility and skin penetration, through reduction of particle size and formation of an amorphous state with hydrogen bonding. Moreover, ENDS was superior to raw eupafolin in attenuating PM-induced oxidative stress and inflammation in HaCaT keratinocytes, by mediating the antioxidant pathway (decreased reactive oxygen species production and nicotinamide adenine dinucleotide phosphate oxidase activity) and anti-inflammation pathway (decreased cyclooxygenase-2 expression and prostaglandin E2 production through downregulation of mitogen-activated protein kinase and nuclear factor-κB signaling). In summary, ENDS shows better antioxidant and anti-inflammatory activities than raw eupafolin through improvement of water solubility and skin penetration. Therefore, ENDS may potentially be used as a medicinal drug and/or cosmeceutical product to prevent PM-induced skin inflammation. PMID:27570454

Aneuploidogenic effects and DNA oxidation induced in vitro by differently sized gold nanoparticles

Directory of Open Access Journals (Sweden)

Di Bucchianico S

2014-05-01

Full Text Available Sebastiano Di Bucchianico,1 Maria Rita Fabbrizi,1 Silvia Cirillo,1 Chiara Uboldi,1 Douglas Gilliland,2 Eugenia Valsami-Jones,3,4 Lucia Migliore11Department of Translational Research and New Technologies in Medicine and Surgery, Medical Genetics Unit, University of Pisa, Pisa, Italy; 2European Commission-Joint Research Centre, Institute for Health and Consumer Protection, NanoBioSciences Unit, Ispra, Italy; 3School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK; 4Earth Sciences, Natural History Museum, Cromwell Road, London, UKAbstract: Gold nanoparticles (Au NPs are used in many fields, including biomedical applications; however, no conclusive information on their potential cytotoxicity and genotoxicity mechanisms is available. For this reason, experiments in human primary lymphocytes and murine macrophages (Raw264.7 were performed exposing cells to spherical citrate-capped Au NPs with two different nominal diameters (5 nm and 15 nm. The proliferative activity, mitotic, apoptotic, and necrotic markers, as well as chromosomal damage were assessed by the cytokinesis-block micronucleus cytome assay. Fluorescence in situ hybridization with human and murine pancentromeric probes was applied to distinguish between clastogenic and aneuploidogenic effects. Our results indicate that 5 nm and 15 nm Au NPs are able to inhibit cell proliferation by apoptosis and to induce chromosomal damage, in particular chromosome mis-segregation. DNA strand breaks were detected by comet assay, and the modified protocol using endonuclease-III and formamidopyrimidine-DNA glycosylase restriction enzymes showed that pyrimidines and purines were oxidatively damaged by Au NPs. Moreover, we show a size-independent correlation between the cytotoxicity of Au NPs and their tested mass concentration or absolute number, and genotoxic effects which were more severe for Au NP 15 nm compared to Au NP 5 nm. Results indicate that

Preparation and characterization of copper oxide nanoparticles decorated carbon nanoparticles using laser ablation in liquid

Science.gov (United States)

Khashan, K. S.; Jabir, M. S.; Abdulameer, F. A.

2018-05-01

Carbon nanoparticles CNPs ecorated by copper oxide nano-sized particles would be successfully equipped using technique named pulsed laser ablation in liquid. The XRD pattern proved the presence of phases assigned to carbon and different phases of copper oxide. The chemical structure of the as-prepared nanoparticles samples was decided by Energy Dispersive Spectrum (EDS) measurement. EDS analysis results show the contents of Carbon, Oxygen and Copper in the final product. These nanoparticles were spherical shaped with a size distribution 10 to 80 nm or carbon nanoparticles and 5 to 50 nm for carbon decorated copper oxide nanoparticles, according to Transmission Electron Microscopy (TEM) images and particle-size distribution histogram. It was found that after doping with copper oxide, nanoparticles become smaller and more regular in shape. Optical absorption spectra of prepared nanoparticles were measured using UV–VIS spectroscopy. The absorption spectrum of carbon nanoparticles without doping indicates absorption peak at about 228 nm. After doping with copper oxide, absorption shows appearance of new absorption peak at about (254-264) nm, which is referred to the movement of the charge between 2p and 4s band of Cu2+ ions.

Anticancer activity of Ficus religiosa engineered copper oxide nanoparticles

International Nuclear Information System (INIS)

Sankar, Renu; Maheswari, Ramasamy; Karthik, Selvaraju; Shivashangari, Kanchi Subramanian; Ravikumar, Vilwanathan

2014-01-01

The design, synthesis, characterization and application of biologically synthesized nanomaterials have become a vital branch of nanotechnology. There is a budding need to develop a method for environmentally benign metal nanoparticle synthesis, that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on an eco-friendly process for rapid synthesis of copper oxide nanoparticles using Ficus religiosa leaf extract as reducing and protecting agent. The synthesized copper oxide nanoparticles were confirmed by UV–vis spectrophotometer, absorbance peaks at 285 nm. The copper oxide nanoparticles were analyzed with field emission-scanning electron microscope (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD) spectrum. The FE-SEM and DLS analyses exposed that copper oxide nanoparticles are spherical in shape with an average particle size of 577 nm. FT-IR spectral analysis elucidates the occurrence of biomolecules required for the reduction of copper oxide ions. Zeta potential studies showed that the surface charge of the formed nanoparticles was highly negative. The XRD pattern revealed that synthesized nanoparticles are crystalline in nature. Further, biological activities of the synthesized nanoparticles were confirmed based on its stable anti-cancer effects. The apoptotic effect of copper oxide nanoparticles is mediated by the generation of reactive oxygen species (ROS) involving the disruption of mitochondrial membrane potential (Δψm) in A549 cells. The observed characteristics and results obtained in our in vitro assays suggest that the copper nanoparticles might be a potential anticancer agent. - Highlights: • Biogenic synthesis of copper oxide nanoparticles by leaf extract of Ficus religiosa • Characterized via UV–vis, FT-IR, DLS, FE-SEM with EDAX and XRD • Protein may act as an encapsulating, reducing and stabilizing

Anticancer activity of Ficus religiosa engineered copper oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Sankar, Renu; Maheswari, Ramasamy; Karthik, Selvaraju [Department of Biochemistry, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu (India); Shivashangari, Kanchi Subramanian, E-mail: shivashangari@gmail.com [Regional Forensic Science Laboratory, Tiruchirapalli, Tamilnadu (India); Ravikumar, Vilwanathan, E-mail: ravikumarbdu@gmail.com [Department of Biochemistry, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu (India)

2014-11-01

The design, synthesis, characterization and application of biologically synthesized nanomaterials have become a vital branch of nanotechnology. There is a budding need to develop a method for environmentally benign metal nanoparticle synthesis, that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on an eco-friendly process for rapid synthesis of copper oxide nanoparticles using Ficus religiosa leaf extract as reducing and protecting agent. The synthesized copper oxide nanoparticles were confirmed by UV–vis spectrophotometer, absorbance peaks at 285 nm. The copper oxide nanoparticles were analyzed with field emission-scanning electron microscope (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD) spectrum. The FE-SEM and DLS analyses exposed that copper oxide nanoparticles are spherical in shape with an average particle size of 577 nm. FT-IR spectral analysis elucidates the occurrence of biomolecules required for the reduction of copper oxide ions. Zeta potential studies showed that the surface charge of the formed nanoparticles was highly negative. The XRD pattern revealed that synthesized nanoparticles are crystalline in nature. Further, biological activities of the synthesized nanoparticles were confirmed based on its stable anti-cancer effects. The apoptotic effect of copper oxide nanoparticles is mediated by the generation of reactive oxygen species (ROS) involving the disruption of mitochondrial membrane potential (Δψm) in A549 cells. The observed characteristics and results obtained in our in vitro assays suggest that the copper nanoparticles might be a potential anticancer agent. - Highlights: • Biogenic synthesis of copper oxide nanoparticles by leaf extract of Ficus religiosa • Characterized via UV–vis, FT-IR, DLS, FE-SEM with EDAX and XRD • Protein may act as an encapsulating, reducing and stabilizing

Toxicity assessment and comparison between two types of iron oxide nanoparticles in Mytilus galloprovincialis

Energy Technology Data Exchange (ETDEWEB)

Taze, Chrysa; Panetas, Ioannis [Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kalogiannis, Stavros [Alexander Technological Educational Institution of Thessaloniki, Department of Nutrition and Dietetics, Thessaloniki (Greece); Feidantsis, Konstantinos [Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Gallios, George P. [Laboratory of General & Inorganic Chemical Technology, School of Chemistry, Aristotle University, GR-54124 Thessaloniki (Greece); Kastrinaki, Georgia [Aerosol & Particle Technology Laboratory, CERTH/CPERI, P.O. Box 60361, 57001 Thessaloniki (Greece); Konstandopoulos, Athanasios G. [Aerosol & Particle Technology Laboratory, CERTH/CPERI, P.O. Box 60361, 57001 Thessaloniki (Greece); Department of Chemical Engineering, Aristotle University, PO. Box 1517, 54006 Thessaloniki (Greece); Václavíková, Miroslava; Ivanicova, Lucia [Institute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, SK-04001 Kosice (Slovakia); Kaloyianni, Martha, E-mail: kaloyian@bio.auth.gr [Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

2016-03-15

Highlights: • The impact of two types of iron oxide nanoparticles on the physiological status of mussels was studied. • Oxidative parameters significantly changed after 1, 3, 7 days of exposure. • The nanoparticles induced oxidative stress to the animals. • All the parameters measured could be applied in biomonitoring studies. - Abstract: Nanoparticles (NPs), due to their increased application and production, are being released into the environment with unpredictable impact on the physiology of marine organisms, as well as on entire ecosystems and upcoming effects on human health. The aim of the present study was to evaluate and compare the oxidative responses of the mussel Mytilus galloprovincialis after exposure to iron oxide NPs and to iron oxide NPs incorporated into zeolite for 1, 3 and 7 days. Our results showed that both effectors induced changes on animal physiology by causing oxidative stress in hemocytes of exposed mussels compared to control animals. This was shown by the significant increase in reactive oxygen species (ROS) production, protein carbonylation, lipid peroxidation, ubiquitin conjugates and DNA damage. In addition an increase in prooxidant levels as measured by the prooxidant-antioxidant balance (PAB) assay was observed in exposed mussels’ hemolymph. The results show that ROS, DNA damage, protein and lipid oxidation, ubiquitin conjugates and PAB could constitute, after further investigation, reliable biomarkers for the evaluation of pollution or other environmental stressors. In addition, more studies are needed in order to ensure the safety of these NPs on various biomedical applications, since it is critical to design NPs that they meet the demands of application without causing cellular toxicity.

Toxicity assessment and comparison between two types of iron oxide nanoparticles in Mytilus galloprovincialis

International Nuclear Information System (INIS)

Taze, Chrysa; Panetas, Ioannis; Kalogiannis, Stavros; Feidantsis, Konstantinos; Gallios, George P.; Kastrinaki, Georgia; Konstandopoulos, Athanasios G.; Václavíková, Miroslava; Ivanicova, Lucia; Kaloyianni, Martha

2016-01-01

Highlights: • The impact of two types of iron oxide nanoparticles on the physiological status of mussels was studied. • Oxidative parameters significantly changed after 1, 3, 7 days of exposure. • The nanoparticles induced oxidative stress to the animals. • All the parameters measured could be applied in biomonitoring studies. - Abstract: Nanoparticles (NPs), due to their increased application and production, are being released into the environment with unpredictable impact on the physiology of marine organisms, as well as on entire ecosystems and upcoming effects on human health. The aim of the present study was to evaluate and compare the oxidative responses of the mussel Mytilus galloprovincialis after exposure to iron oxide NPs and to iron oxide NPs incorporated into zeolite for 1, 3 and 7 days. Our results showed that both effectors induced changes on animal physiology by causing oxidative stress in hemocytes of exposed mussels compared to control animals. This was shown by the significant increase in reactive oxygen species (ROS) production, protein carbonylation, lipid peroxidation, ubiquitin conjugates and DNA damage. In addition an increase in prooxidant levels as measured by the prooxidant-antioxidant balance (PAB) assay was observed in exposed mussels’ hemolymph. The results show that ROS, DNA damage, protein and lipid oxidation, ubiquitin conjugates and PAB could constitute, after further investigation, reliable biomarkers for the evaluation of pollution or other environmental stressors. In addition, more studies are needed in order to ensure the safety of these NPs on various biomedical applications, since it is critical to design NPs that they meet the demands of application without causing cellular toxicity.

The prospective protective effect of selenium nanoparticles against chromium-induced oxidative and cellular damage in rat thyroid

Directory of Open Access Journals (Sweden)

Hassanin KMA

2013-05-01

Full Text Available Kamel MA Hassanin,1 Samraa H Abd El-Kawi,2 Khalid S Hashem1 1Department of Biochemistry, Faculty of Veterinary Medicine, 2Department of Histology, Faculty of Medicine, Beni-Suef University, Beni-Suef, Egypt Background: Nanotechnology has enabled researchers to synthesize nanosize particles that possess increased surface areas. Compared to conventional microparticles, it has resulted in increased interactions with biological targets. Objective: The objective of this study was to determine the protective ability of selenium nanoparticles against hexavalent chromium-induced thyrotoxicity. Design: Twenty male rats were used in the study, and arbitrarily assigned to four groups. Group 1 was the control group, and was given phosphate-buffered saline. Group 2 was the chromium-treated group and was given K2Cr2O7 60 µg/kg body weight intraperitoneally as a single dose on the third day of administration. Group 3 was the nano-selenium-treated group and was given selenium nanoparticles (size 3–20 nm 0.5 mg/kg body weight intraperitoneally daily for 5 consecutive days. Group 4 was the nano-selenium chromium-treated group, which received selenium nanoparticles for 5 days and a single dose of K2Cr2O7 on the third day of administration. Materials and methods: Blood samples were collected from rats for measuring thyroid hormones (free triiodothyronine [T3] and free thyroxine [T4] and oxidative and antioxidant parameters (malondialdehyde [MDA], reduced glutathione [GSH], catalase, and superoxide dismutase [SOD]. Upon dissection, thyroid glands were taken for histopathological examination by using paraffin preparations stained with hematoxylin and eosin (H&E and Masson’s trichrome. Immunohistochemical staining was performed for detecting cellular proliferation using Ki67 antibodies. Results: The present study shows that K2Cr2O7 has a toxic effect on the thyroid gland as a result of inducing a marked oxidative damage and release of reactive oxygen species

Magnetic ferroferric oxide nanoparticles induce vascular endothelial cell dysfunction and inflammation by disturbing autophagy

Energy Technology Data Exchange (ETDEWEB)

Zhang, Lu, E-mail: chaperones@163.com [College of Bioengineering, Henan University of Technology, Lianhua Street, Zhengzhou 450001 (China); Wang, XueQin; Miao, YiMing; Chen, ZhiQiang; Qiang, PengFei; Cui, LiuQing; Jing, Hongjuan [College of Bioengineering, Henan University of Technology, Lianhua Street, Zhengzhou 450001 (China); Guo, YuQi [Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052 (China)

2016-03-05

Highlights: • B-Fe{sub 3}O{sub 4}NPs did not induce cell apoptosis or necrosis in HUVECs within 24 h. • B-Fe{sub 3}O{sub 4}NPs induced HUVEC dysfunction and inflammation. • B-Fe{sub 3}O{sub 4}NPs induced enhanced autophagic activity and blockade of autophagy flux. • Suppression of autophagy dysfunction attenuated B-Fe{sub 3}O{sub 4}NP-induced HUVEC dysfunction. - Abstract: Despite the considerable use of magnetic ferroferric oxide nanoparticles (Fe{sub 3}O{sub 4}NPs) worldwide, their safety is still an important topic of debate. In the present study, we detected the toxicity and biological behavior of bare-Fe{sub 3}O{sub 4}NPs (B-Fe{sub 3}O{sub 4}NPs) on human umbilical vascular endothelial cells (HUVECs). Our results showed that B-Fe{sub 3}O{sub 4}NPs did not induce cell death within 24 h even at concentrations up to 400 μg/ml. The level of nitric oxide (NO) and the activity of endothelial NO synthase (eNOS) were decreased after exposure to B-Fe{sub 3}O{sub 4}NPs, whereas the levels of proinflammatory cytokines were elevated. Importantly, B-Fe{sub 3}O{sub 4}NPs increased the accumulation of autophagosomes and LC3-II in HUVECs through both autophagy induction and the blockade of autophagy flux. The levels of Beclin 1 and VPS34, but not phosphorylated mTOR, were increased in the B-Fe{sub 3}O{sub 4}NP-treated HUVECs. Suppression of autophagy induction or stimulation of autophagy flux, at least partially, attenuated the B-Fe{sub 3}O{sub 4}NP-induced HUVEC dysfunction. Additionally, enhanced autophagic activity might be linked to the B-Fe{sub 3}O{sub 4}NP-induced production of proinflammatory cytokines. Taken together, these results demonstrated that B-Fe{sub 3}O{sub 4}NPs disturb the process of autophagy in HUVECs, and eventually lead to endothelial dysfunction and inflammation.

Oxide nanoparticles in an Al-alloyed oxide dispersion strengthened steel: crystallographic structure and interface with ferrite matrix

Science.gov (United States)

Zhang, Zhenbo; Pantleon, Wolfgang

2017-07-01

Oxide nanoparticles are quintessential for ensuring the extraordinary properties of oxide dispersion strengthened (ODS) steels. In this study, the crystallographic structure of oxide nanoparticles, and their interface with the ferritic steel matrix in an Al-alloyed ODS steel, i.e. PM2000, were systematically investigated by high-resolution transmission electron microscopy. The majority of oxide nanoparticles were identified to be orthorhombic YAlO3. During hot consolidation and extrusion, they develop a coherent interface and a near cuboid-on-cube orientation relationship with the ferrite matrix in the material. After annealing at 1200 °C for 1 h, however, the orientation relationship between the oxide nanoparticles and the matrix becomes arbitrary, and their interface mostly incoherent. Annealing at 1300 °C leads to considerable coarsening of oxide nanoparticles, and a new orientation relationship of pseudo-cube-on-cube between oxide nanoparticles and ferrite matrix develops. The reason for the developing interfaces and orientation relationships between oxide nanoparticles and ferrite matrix under different conditions is discussed.

Copper(ii) oxide nanoparticles penetrate into HepG2 cells, exert cytotoxicity via oxidative stress and induce pro-inflammatory response

Science.gov (United States)

Piret, Jean-Pascal; Jacques, Diane; Audinot, Jean-Nicolas; Mejia, Jorge; Boilan, Emmanuelle; Noël, Florence; Fransolet, Maude; Demazy, Catherine; Lucas, Stéphane; Saout, Christelle; Toussaint, Olivier

2012-10-01

The potential toxic effects of two types of copper(ii) oxide (CuO) nanoparticles (NPs) with different specific surface areas, different shapes (rod or spheric), different sizes as raw materials and similar hydrodynamic diameter in suspension were studied on human hepatocarcinoma HepG2 cells. Both CuO NPs were shown to be able to enter into HepG2 cells and induce cellular toxicity by generating reactive oxygen species. CuO NPs increased the abundance of several transcripts coding for pro-inflammatory interleukins and chemokines. Transcriptomic data, siRNA knockdown and DNA binding activities suggested that Nrf2, NF-κB and AP-1 were implicated in the response of HepG2 cells to CuO NPs. CuO NP incubation also induced activation of MAPK pathways, ERKs and JNK/SAPK, playing a major role in the activation of AP-1. In addition, cytotoxicity, inflammatory and antioxidative responses and activation of intracellular transduction pathways induced by rod-shaped CuO NPs were more important than spherical CuO NPs. Measurement of Cu2+ released in cell culture medium suggested that Cu2+ cations released from CuO NPs were involved only to a small extent in the toxicity induced by these NPs on HepG2 cells.The potential toxic effects of two types of copper(ii) oxide (CuO) nanoparticles (NPs) with different specific surface areas, different shapes (rod or spheric), different sizes as raw materials and similar hydrodynamic diameter in suspension were studied on human hepatocarcinoma HepG2 cells. Both CuO NPs were shown to be able to enter into HepG2 cells and induce cellular toxicity by generating reactive oxygen species. CuO NPs increased the abundance of several transcripts coding for pro-inflammatory interleukins and chemokines. Transcriptomic data, siRNA knockdown and DNA binding activities suggested that Nrf2, NF-κB and AP-1 were implicated in the response of HepG2 cells to CuO NPs. CuO NP incubation also induced activation of MAPK pathways, ERKs and JNK/SAPK, playing a major

Cetuximab-conjugated iron oxide nanoparticles for cancer imaging and therapy

Directory of Open Access Journals (Sweden)

Tseng SH

2015-05-01

Full Text Available Shih-Heng Tseng,1,2 Min-Yuan Chou,2 I-Ming Chu1 1Department of Chemical Engineering, National Tsing Hua University, 2Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan Abstract: We have developed a theranostic nanoparticle, ie, cet-PEG-dexSPIONs, by conjugation of the anti-epidermal growth factor receptor (EGFR monoclonal antibody, cetuximab, to dextran-coated superparamagnetic iron oxide nanoparticles (SPIONs via periodate oxidation. Approximately 31 antibody molecules were conjugated to each nanoparticle. Cet-PEG-dexSPIONs specifically bind to EGFR-expressing tumor cells and enhance image contrast on magnetic resonance imaging. Cet-PEG-dexSPION-treated A431 cells showed significant inhibition of epidermal growth factor-induced EGFR phosphorylation and enhancement of EGFR internalization and degradation. In addition, a significant increase in apoptosis was detected in EGFR-overexpressing cell lines, A431 and 32D/EGFR, after 24 hours of incubation at 37°C with cet-PEG-dexSPIONs compared with cetuximab alone. The antibody-dependent cell-mediated cytotoxicity of cetuximab was observed in cet-PEG-dexSPIONs. The results demonstrated that cet-PEG-dexSPIONs retained the therapeutic effect of cetuximab in addition to having the ability to target and image EGFR-expressing tumors. Cet-PEG-dexSPIONs represent a promising targeted magnetic probe for early detection and treatment of EGFR-expressing tumor cells. Keywords: epidermal growth factor receptor, cetuximab, superparamagnetic iron oxide nanoparticle, magnetic resonance imaging, sodium periodate, polyethylene glycol

Comparative Study of Antidiabetic Activity and Oxidative Stress Induced by Zinc Oxide Nanoparticles and Zinc Sulfate in Diabetic Rats.

Science.gov (United States)

Nazarizadeh, Ali; Asri-Rezaie, Siamak

2016-08-01

In the current study, antidiabetic activity and toxic effects of zinc oxide nanoparticles (ZnO) were investigated in diabetic rats compared to zinc sulfate (ZnSO4) with particular emphasis on oxidative stress parameters. One hundred and twenty male Wistar rats were divided into two healthy and diabetic groups, randomly. Each major group was further subdivided into five subgroups and then orally supplemented with various doses of ZnO (1, 3, and 10 mg/kg) and ZnSO4 (30 mg/kg) for 56 consecutive days. ZnO showed greater antidiabetic activity compared to ZnSO4 evidenced by improved glucose disposal, insulin levels, and zinc status. The altered activities of erythrocyte antioxidant enzymes as well as raised levels of lipid peroxidation and a marked reduction of total antioxidant capacity were observed in rats receiving ZnO. ZnO nanoparticles acted as a potent antidiabetic agent, however, severely elicited oxidative stress particularly at higher doses.

Mechanism of oxidative stress involved in the toxicity of ZnO nanoparticles against eukaryotic cells

Directory of Open Access Journals (Sweden)

M. Saliani

2016-01-01

Full Text Available ZnO NPs (zinc oxide nanoparticles has generated significant scientific interest as a novel antibacterial and anticancer agent. Since oxidative stress is a critical determinant of ZnO NPs-induced damage, it is necessary to characterize their underlying mode of action. Different structural and physicochemical properties of ZnO NPs such as particle surface, size, shape, crystal structure, chemical position, and presence of metals can lead to changes in biological activities including ROS (reactive oxygen species production. However, there are some inconsistencies in the literature on the relation between the physicochemical features of ZnO NPs and their plausible oxidative stress mechanism. Herein, the possible oxidative stress mechanism of ZnO NPs was reviewed. This is worthy of further detailed evaluations in order to improve our understanding of vital NPs characteristics governing their toxicity. Therefore, this study focuses on the different reported oxidative stress paradigms induced by ZnO NPs including ROS generated by NPs, oxidative stress due to the NPs-cell interaction, and role of the particle dissolution in the oxidative damage. Also, this study tries to characterize and understand the multiple pathways involved in oxidative stress induced by ZnO NPs. Knowledge about different cellular signaling cascades stimulated by ZnO NPs lead to the better interpretation of the toxic influences induced by the cellular and acellular parameters. Regarding the potential benefits of toxic effects of ZnO NPs, in-depth evaluation of their toxicity mechanism and various effects of these nanoparticles would facilitate their implementation for biomedical applications.

Linear-chain assemblies of iron oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Dhak, Prasanta; Kim, Min-Kwan; Lee, Jae Hyeok; Kim, Miyoung; Kim, Sang-Koog, E-mail: sangkoog@snu.ac.kr

2017-07-01

Highlights: • Hydrothermal synthesis of pure phase 200 nm Fe{sub 3}O{sub 4} nanoparticles. • Studies of linear-chain assemblies of iron oxide nanosphere by FESEM. • Micromagnetic simulations showed the presence of 3D vortex states. • The B.E. for different numbers of particles in linear chain assemblies were calculated. - Abstract: We synthesized iron oxide nanoparticles using a simple hydrothermal approach and found several types of segments of their linear-chain self-assemblies as observed by field emission scanning electron microscopy. X-ray diffraction and transmission electron microscopy measurements confirm a well-defined single-phase FCC structure. Vibrating sample magnetometry measurements exhibit a ferromagnetic behavior. Micromagnetic numerical simulations show magnetic vortex states in the nanosphere model. Also, calculations of binding energies for different numbers of particles in the linear-chain assemblies explain a possible mechanism responsible for the self-assemblies of segments of the linear chains of nanoparticles. This work offers a step towards linear-chain self-assemblies of iron oxide nanoparticles and the effect of magnetic vortex states in individual nanoparticles on their binding energy.

Toxicity, toxicokinetics and biodistribution of dextran stabilized Iron oxide Nanoparticles for biomedical applications.

Science.gov (United States)

Remya, N S; Syama, S; Sabareeswaran, A; Mohanan, P V

2016-09-10

Advancement in the field of nanoscience and technology has alarmingly raised the call for comprehending the potential health effects caused by deliberate or unintentional exposure to nanoparticles. Iron oxide magnetic nanoparticles have an increasing number of biomedical applications and hence a complete toxicological profile of the nanomaterial is therefore a mandatory requirement prior to its intended usage to ensure safety and to minimize potential health hazards upon its exposure. The present study elucidates the toxicity of in house synthesized Dextran stabilized iron oxide nanoparticles (DINP) in a regulatory perspective through various routes of exposure, its associated molecular, immune, genotoxic, carcinogenic effects and bio distribution profile. Synthesized ferrite nanomaterials were successfully coated with dextran (dextran helps in improvising particle stability in biological environments. The nanoparticles do not seem to induce oxidative stress mediated toxicological effects, nor altered physiological process or behavior changes or visible pathological lesions. Furthermore no anticipated health hazards are likely to be associated with the use of DINP and could be concluded that the synthesized DINP is nontoxic/safe to be used for biomedical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrasmall iron oxide nanoparticles for biomedical applications: improving the colloidal and magnetic properties.

Science.gov (United States)

Costo, Rocio; Bello, Valentina; Robic, Caroline; Port, Marc; Marco, Jose F; Puerto Morales, M; Veintemillas-Verdaguer, Sabino

2012-01-10

A considerable increase in the saturation magnetization, M(s) (40%), and initial susceptibility of ultrasmall (<5 nm) iron oxide nanoparticles prepared by laser pyrolysis was obtained through an optimized acid treatment. Moreover, a significant enhancement in the colloidal properties, such as smaller aggregate sizes in aqueous media and increased surface charge densities, was found after this chemical protocol. The results are consistent with a reduction in nanoparticle surface disorder induced by a dissolution-recrystallization mechanism.

X-ray diffraction on nanoparticles chromium and nickel oxides obtained by gelatin using synchrotron radiation

International Nuclear Information System (INIS)

Menezes, Alan Silva de; Medeiros, Angela Maria de Lemos; Miranda, Marcus Aurelio Ribeiro; Almeida, Juliana Marcela Abraao; Remedios, Claudio Marcio Rocha; Silva, Lindomar R.D. da; Gouveia, S.T.; Sasaki, Jose Marcos; Jardim, P.M.

2003-01-01

Full text: Cr 2 O 3 nanoparticles has many applications like green pigments, wear resistance, and coating materials for thermal protection. Several methods to produce chromium oxide nanoparticles have already been studied, gas condensation, laser induced pyrolysis, microwave plasma, sol-gel and gamma radiation methods. Many applications for this kind of material can be provide concerning the particle size. For instance, particle size approximately of 200 nm are preferable as pigment due to its opacity and below 50 nm can be used as transparent pigment. In this work we have demonstrated that chromium and nickel oxide nanoparticles can be prepared by gelatin method. X-Ray diffraction (XRD) show that mean particle size for chromium oxide of 15-150 nm and nickel oxide of 90 nm were obtained for several temperature of sintering. The X-Ray powder diffraction pattern were performed using Synchrotron Radiation X-Ray source at XRD1 beamline in National Laboratory of Light Synchrotron (LNLS). (author)

Shifts in oxidation states of cerium oxide nanoparticles detected inside intact hydrated cells and organelles

Energy Technology Data Exchange (ETDEWEB)

Szymanski, Craig J.; Munusamy, Prabhakaran; Mihai, Cosmin; Xie, Yumei; Hu, Dehong; Gilles, Marry K.; Tyliszczak, T.; Thevuthasan, Suntharampillai; Baer, Donald R.; Orr, Galya

2015-09-01

Cerium oxide nanoparticles (CNPs) have been shown to induce diverse biological effects, ranging from toxic to beneficial. The beneficial effects have been attributed to the potential antioxidant activity of CNPs via certain redox reactions, depending on their oxidation state or Ce3+/Ce4+ ratio. However, this ratio is strongly dependent on the environment and age of the nanoparticles and it is unclear whether and how the complex intracellular environment impacts this ratio and the possible redox reactions of CNPs. To identify any changes in the oxidation state of CNPs in the intracellular environment and better understand their intracellular reactions, we directly quantified the oxidation states of CNPs outside and inside intact hydrated cells and organelles using correlated scanning transmission x-ray and super resolution fluorescence microscopies. By analyzing hundreds of small CNP aggregates, we detected a shift to a higher Ce3+/Ce4+ ratio in CNPs inside versus outside the cells, indicating a net reduction of CNPs in the intracellular environment. We further found a similar ratio in the cytoplasm and in the lysosomes, indicating that the net reduction occurs earlier in the internalization pathway. Together with oxidative stress and toxicity measurements, our observations identify a net reduction of CNPs in the intracellular environment, which is consistent with their involvement in potentially beneficial oxidation reactions, but also point to interactions that can negatively impact the health of cells.

Structural and magnetic properties of core-shell iron-iron oxide nanoparticles

DEFF Research Database (Denmark)

Kuhn, Luise Theil; Bojesen, A.; Timmermann, L.

2002-01-01

We present studies of the structural and magnetic properties of core-shell iron-iron oxide nanoparticles. alpha-Fe nanoparticles were fabricated by sputtering and subsequently covered with a protective nanocrystalline oxide shell consisting of either maghaemite (gamma-Fe2O3) or partially oxidized...... magnetite (Fe3O4). We observed that the nanoparticles were stable against further oxidation, and Mossbauer spectroscopy at high applied magnetic fields and low temperatures revealed a stable form of partly oxidized magnetite. The nanocrystalline structure of the oxide shell results in strong canting...... of the spin structure in the oxide shell, which thereby modifies the magnetic properties of the core-shell nanoparticles....

Enzymatic biosensors based on the use of metal oxide nanoparticles

International Nuclear Information System (INIS)

Shi, Xinhao; Gu, Wei; Li, Bingyu; Chen, Ningning; Zhao, Kai; Xian, Yuezhong

2014-01-01

Over the past decades, various techniques have been developed to obtain materials at a nanoscale level to design biosensors with high sensitivity, selectivity and efficiency. Metal oxide nanoparticles (MONPs) are of particular interests and have received much attention because of their unique physical, chemical and catalytic properties. This review summarizes the progress made in enzymatic biosensors based on the use of MONPs. Synthetic methods, strategies for immobilization, and the functions of MONPs in enzymatic biosensing systems are reviewed and discussed. The article is subdivided into sections on enzymatic biosensors based on (a) zinc oxide nanoparticles, (b) titanium oxide nanoparticles, (c) iron oxide nanoparticles, and (d) other metal oxide nanoparticles. While substantial advances have been made in MONPs-based enzymatic biosensors, their applications to real samples still lie ahead because issues such as reproducibility and sensor stability have to be solved. (author)

Immobilized WO3 nanoparticles on graphene oxide as a photo-induced antibacterial agent against UV-resistant Bacillus pumilus

Science.gov (United States)

Hosseini, Farshad; Rasuli, Reza; Jafarian, Vahab

2018-04-01

We present the antibacterial and photo-catalytic activity of immobilized WO3 nanoparticles on graphene oxide sheets. WO3 nanoparticles were immobilized on graphene oxide using the arc discharge method in arc currents of 5, 20, 40 and 60 A. Tauc plots of the UV-visible spectra show that the band gap of the prepared samples decreases (to ~2.7 eV) with respect to the WO3 nanoparticles. Photo-catalytic activity was examined by the degradation of rhodamine B under ultra-violet irradiation and the results show that the photo-catalytic activity of WO3 nanoparticles is increased by immobilizing them on graphene oxide sheets. In addition, the photo-degradation yield of the samples prepared by the 5 A arc current is 84% in 120 min, which is more than that of the other samples. The antibacterial activity of the prepared samples was studied against Bacillus pumilus (B. pumilus) bacteria, showing high resistance to ultra-violet exposure. Our results show that the bare and immobilized WO3 nanoparticles become more active under UV irradiation and their antibacterial properties are comparable with Ag nanoparticles. Besides this, the results show that although the photo-catalytic activity of the post-annealed samples at 500 °C is less than the as-prepared samples, it is, however, more active against B. pumilus bacteria under UV irradiation.

Exposure to nickel oxide nanoparticles induces pulmonary inflammation through NLRP3 inflammasome activation in rats.

Science.gov (United States)

Cao, Zhengwang; Fang, Yiliang; Lu, Yonghui; Qian, Fenghua; Ma, Qinglong; He, Mingdi; Pi, Huifeng; Yu, Zhengping; Zhou, Zhou

2016-01-01

With recent advances in the manufacture and application of nickel oxide nanoparticles (NiONPs), concerns about their adverse effects on the respiratory system are increasing. However, the underlying cellular and molecular mechanisms of NiONP-induced pulmonary toxicity remain unclear. In this study, we focused on the impacts of NiONPs on pulmonary inflammation and investigated whether the NLRP3 inflammasome is involved in NiONP-induced pulmonary inflammation and injury. NiONP suspensions were administered by single intratracheal instillation to rats, and inflammatory responses were evaluated at 3 days, 7 days, or 28 days after treatment. NiONP exposure resulted in sustained pulmonary inflammation accompanied by inflammatory cell infiltration, alveolar proteinosis, and cytokine secretion. Expression of Nlrp3 was markedly upregulated by the NiONPs, which was accompanied by overexpression of the active form of caspase-1 (p20) and interleukin (IL)-1β secretion in vivo. NiONP-induced IL-1β secretion was partially prevented by co-treatment with a caspase-1 inhibitor in macrophages. Moreover, siRNA-mediated Nlrp3 knockdown completely attenuated NiONP-induced cytokine release and caspase-1 activity in macrophages in vitro. In addition, NiONP-induced NLRP3 inflammasome activation requires particle uptake and reactive oxygen species production. Collectively, our findings suggest that the NLRP3 inflammasome participates in NiONP-induced pulmonary inflammation and offer new strategies to combat the pulmonary toxicity induced by NiONPs.

Acid monolayer functionalized iron oxide nanoparticle catalysts

Science.gov (United States)

Ikenberry, Myles

Superparamagnetic iron oxide nanoparticle functionalization is an area of intensely active research, with applications across disciplines such as biomedical science and heterogeneous catalysis. This work demonstrates the functionalization of iron oxide nanoparticles with a quasi-monolayer of 11-sulfoundecanoic acid, 10-phosphono-1-decanesulfonic acid, and 11-aminoundecanoic acid. The carboxylic and phosphonic moieties form bonds to the iron oxide particle core, while the sulfonic acid groups face outward where they are available for catalysis. The particles were characterized by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), potentiometric titration, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectrometry (XPS), and dynamic light scattering (DLS). The sulfonic acid functionalized particles were used to catalyze the hydrolysis of sucrose at 80° and starch at 130°, showing a higher activity per acid site than the traditional solid acid catalyst Amberlyst-15, and comparing well against results reported in the literature for sulfonic acid functionalized mesoporous silicas. In sucrose catalysis reactions, the phosphonic-sulfonic nanoparticles (PSNPs) were seen to be incompletely recovered by an external magnetic field, while the carboxylic-sulfonic nanoparticles (CSNPs) showed a trend of increasing activity over the first four recycle runs. Between the two sulfonic ligands, the phosphonates produced a more tightly packed monolayer, which corresponded to a higher sulfonic acid loading, lower agglomeration, lower recoverability through application of an external magnetic field, and higher activity per acid site for the hydrolysis of starch. Functionalizations with 11-aminoundecanoic acid resulted in some amine groups binding to the surfaces of iron oxide nanoparticles. This amine binding is commonly ignored in iron oxide

Intratracheal instillation of cerium oxide nanoparticles induces hepatic toxicity in male Sprague-Dawley rats

Directory of Open Access Journals (Sweden)

Nalabotu SK

2011-10-01

Full Text Available Siva K Nalabotu1,2, Madhukar B Kolli1,2, William E Triest3,4, Jane Y Ma5, Nandini DPK Manne2,6, Anjaiah Katta1,2, Hari S Addagarla2, Kevin M Rice2,6–8, Eric R Blough1,2,6,7,91Department of Pharmacology, Physiology and Toxicology, Marshall University, Joan C Edwards School of Medicine; 2Center for Diagnostic Nanosystems, Marshall University; 3Pathology and Laboratory Medicine Service, Veterans Affairs Medical Center; 4Section of Pathology, Department of Anatomy and Pathology, Joan C Edwards School of Medicine, Marshall University, Huntington; 5Health Effects Laboratory Division, NIOSH, Morgantown; 6Department of Biological Sciences; 7School of Kinesiology, College of Health Professions, Marshall University; 8Biotechnology Department, West Virginia State University; 9Department of Cardiology, Joan C Edwards School of Medicine, Marshall University Huntington, WV, USABackground: Cerium oxide (CeO2 nanoparticles have been posited to have both beneficial and toxic effects on biological systems. Herein, we examine if a single intratracheal instillation of CeO2 nanoparticles is associated with systemic toxicity in male Sprague-Dawley rats.Methods and results: Compared with control animals, CeO2 nanoparticle exposure was associated with increased liver ceria levels, elevations in serum alanine transaminase levels, reduced albumin levels, a diminished sodium-potassium ratio, and decreased serum triglyceride levels (P < 0.05. Consistent with these data, rats exposed to CeO2 nanoparticles also exhibited reductions in liver weight (P < 0.05 and dose-dependent hydropic degeneration, hepatocyte enlargement, sinusoidal dilatation, and accumulation of granular material. No histopathological alterations were observed in the kidney, spleen, and heart. Analysis of serum biomarkers suggested an elevation of acute phase reactants and markers of hepatocyte injury in the rats exposed to CeO2 nanoparticles.Conclusion: Taken together, these data suggest that

Synthesis and magnetic characterizations of uniform iron oxide nanoparticles

International Nuclear Information System (INIS)

Jiang, FuYi; Li, XiaoYi; Zhu, Yuan; Tang, ZiKang

2014-01-01

Uniform iron oxide nanoparticles with a cubic shape were prepared by the decomposition of homemade iron oleate in 1-octadecene with the presence of oleic acid. The particle shape and size uniformity are sensitive to the quantity of oleic acid. XRD, HRTEM and SAED results indicated that the main phase content of as-prepared iron oxide nanoparticles is Fe 3 O 4 with an inverse spinel structure. Magnetic measurements revealed that the as-prepared iron oxide nanoparticles display a ferromagnetic behavior with a blocking temperature of 295 K. At low temperatures the magnetic anisotropy of the aligned nanoparticles caused the appearance of a hysteresis loop.

Superparamagnetic iron oxide nanoparticles incorporated into silica nanoparticles by inelastic collision via ultrasonic field: Role of colloidal stability

Energy Technology Data Exchange (ETDEWEB)

Sodipo, Bashiru Kayode; Azlan, Abdul Aziz [Nano-Optoelectronics Research and Technology (NOR) Lab, School of Physics, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia Nano-Biotechnology Research (Malaysia); Innovation (NanoBRI), Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Pulau Pinang (Malaysia)

2015-04-24

Superparamagnetic iron oxide nanoparticles (SPION)/Silica composite nanoparticles were prepared by ultrasonically irradiating colloidal suspension of silica and SPION mixture. Both silica and SPION were synthesized independently via co-precipitation and sol-gel method, respectively. Their mixtures were sonicated at different pH between 3 and 5. Electrophoresis measurement and other physicochemical analyses of the products demonstrate that at lower pH SPION was found incorporated into the silica. However, at pH greater than 4, SPION was unstable and unable to withstand the turbulence flow and shock wave from the ultrasonic field. Results suggest that the formation of the SPION/silica composite nanoparticles is strongly related to the inelastic collision induced by ultrasonic irradiation. More so, the formation the composite nanoparticles via the ultrasonic field are dependent on the zeta potential and colloidal stability of the particles.

Topical application of zinc oxide nanoparticles reduces bacterial skin infection in mice and exhibits antibacterial activity by inducing oxidative stress response and cell membrane disintegration in macrophages.

Science.gov (United States)

Pati, Rashmirekha; Mehta, Ranjit Kumar; Mohanty, Soumitra; Padhi, Avinash; Sengupta, Mitali; Vaseeharan, Baskarlingam; Goswami, Chandan; Sonawane, Avinash

2014-08-01

Here we studied immunological and antibacterial mechanisms of zinc oxide nanoparticles (ZnO-NPs) against human pathogens. ZnO-NPs showed more activity against Staphylococcus aureus and least against Mycobacterium bovis-BCG. However, BCG killing was significantly increased in synergy with antituberculous-drug rifampicin. Antibacterial mechanistic studies showed that ZnO-NPs disrupt bacterial cell membrane integrity, reduce cell surface hydrophobicity and down-regulate the transcription of oxidative stress-resistance genes in bacteria. ZnO-NP treatment also augmented the intracellular bacterial killing by inducing reactive oxygen species production and co-localization with Mycobacterium smegmatis-GFP in macrophages. Moreover, ZnO-NPs disrupted biofilm formation and inhibited hemolysis by hemolysin toxin producing S. aureus. Intradermal administration of ZnO-NPs significantly reduced the skin infection, bacterial load and inflammation in mice, and also improved infected skin architecture. We envision that this study offers novel insights into antimicrobial actions of ZnO-NPs and also demonstrates ZnO-NPs as a novel class of topical anti-infective agent for the treatment of skin infections. This in-depth study demonstrates properties of ZnO nanoparticles in infection prevention and treatment in several skin infection models, dissecting the potential mechanisms of action of these nanoparticles and paving the way to human applications. Copyright © 2014 Elsevier Inc. All rights reserved.

Titanium oxide nanoparticles as additives in engine oil

Directory of Open Access Journals (Sweden)

Meena Laad

2018-04-01

Full Text Available This research study investigates the tribological behaviour of titanium oxide (TiO2 nanoparticles as additives in mineral based multi-grade engine oil. All tests were performed under variable load and varying concentrations of nanoparticles in lubricating oil. The friction and wear experiments were performed using pin-on-disc tribotester. This study shows that mixing of TiO2 nanoparticles in engine oil significantly reduces the friction and wear rate and hence improves the lubricating properties of engine oil. The dispersion analysis of TiO2 nanoparticles in lubricating oil using UV spectrometer confirms that TiO2 nanoparticles possess good stability and solubility in the lubricant and improve the lubricating properties of the engine oil. Keywords: Titanium oxide, Nanoparticles, UV spectrometer, Tribotester, Engine oil

Chemical nature of catalysts of oxide nanoparticles in environment

Indian Academy of Sciences (India)

Carbon nanostructures (CNS) are often grown using oxide nanoparticles as catalyst in chemical vapour deposition and these oxides are not expected to survive as such during growth. In the present study, the catalysts of cobalt- and nickel oxide-based nanoparticles of sizes varying over a range have been reduced at 575 ...

Influence of Camellia sinensis extract on Zinc Oxide nanoparticle green synthesis

Science.gov (United States)

Nava, O. J.; Luque, P. A.; Gómez-Gutiérrez, C. M.; Vilchis-Nestor, A. R.; Castro-Beltrán, A.; Mota-González, M. L.; Olivas, A.

2017-04-01

This work addresses low cost, non-toxic green synthesis of Zinc Oxide nanoparticles prepared using different amounts of Camellia sinensis extract. The Synthesized material was studied and characterized through Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), transmission electron microscopy (TEM). The Zinc Oxide nanoparticles presented the desired Znsbnd O bond at 618 cm-1, demonstrated growth in a purely hexagonal Wurtzite crystal structure, and, depending on the amount of extract used, they presented different size and shape homogeneity. The photocatalytic activity of the obtained Zinc Oxide nanoparticles was studied. The photocatalytic degradation studies were done at a 1:1 M ratio of methylene blue to Zinc Oxide nanoparticles under UV light. The obtained results presented a better degradation rate than commercially available Zinc Oxide nanoparticles.

Ex vivo assessment of polyol coated-iron oxide nanoparticles for MRI diagnosis applications: toxicological and MRI contrast enhancement effects

Science.gov (United States)

Bomati-Miguel, Oscar; Miguel-Sancho, Nuria; Abasolo, Ibane; Candiota, Ana Paula; Roca, Alejandro G.; Acosta, Milena; Schwartz, Simó; Arus, Carles; Marquina, Clara; Martinez, Gema; Santamaria, Jesus

2014-03-01

Polyol synthesis is a promising method to obtain directly pharmaceutical grade colloidal dispersion of superparamagnetic iron oxide nanoparticles (SPIONs). Here, we study the biocompatibility and performance as T2-MRI contrast agents (CAs) of high quality magnetic colloidal dispersions (average hydrodynamic aggregate diameter of 16-27 nm) consisting of polyol-synthesized SPIONs (5 nm in mean particle size) coated with triethylene glycol (TEG) chains (TEG-SPIONs), which were subsequently functionalized to carboxyl-terminated meso-2-3-dimercaptosuccinic acid (DMSA) coated-iron oxide nanoparticles (DMSA-SPIONs). Standard MTT assays on HeLa, U87MG, and HepG2 cells revealed that colloidal dispersions of TEG-coated iron oxide nanoparticles did not induce any loss of cell viability after 3 days incubation with dose concentrations below 50 μg Fe/ml. However, after these nanoparticles were functionalized with DMSA molecules, an increase on their cytotoxicity was observed, so that particles bearing free terminal carboxyl groups on their surface were not cytotoxic only at low concentrations (MRI studies in mice indicated that both types of coated-iron oxide nanoparticles produced higher negative T2-MRI contrast enhancement than that measured for a similar commercial T2-MRI CAs consisting in dextran-coated ultra-small iron oxide nanoparticles (Ferumoxtran-10). In conclusion, the above attributes make both types of as synthesized coated-iron oxide nanoparticles, but especially DMSA-SPIONs, promising candidates as T2-MRI CAs for nanoparticle-enhanced MRI diagnosis applications.

Nickel oxide nanoparticles exert cytotoxicity via oxidative stress and induce apoptotic response in human liver cells (HepG2).

Science.gov (United States)

Ahamed, Maqusood; Ali, Daoud; Alhadlaq, Hisham A; Akhtar, Mohd Javed

2013-11-01

Increasing use of nickel oxide nanoparticles (NiO NPs) necessitates an improved understanding of their potential impact on human health. Previously, toxic effects of NiO NPs have been investigated, mainly on airway cells. However, information on effect of NiO NPs on human liver cells is largely lacking. In this study, we investigated the reactive oxygen species (ROS) mediated cytotoxicity and induction of apoptotic response in human liver cells (HepG2) due to NiO NPs exposure. Prepared NiO NPs were crystalline and spherical shaped with an average diameter of 44 nm. NiO NPs induced cytotoxicity (cell death) and ROS generation in HepG2 cells in dose-dependent manner. Further, ROS scavenger vitamin C reduced cell death drastically caused by NiO NPs exposure indicating that oxidative stress plays an important role in NiO NPs toxicity. Micronuclei induction, chromatin condensation and DNA damage in HepG2 cells treated with NiO NPs suggest that NiO NPs induced cell death via apoptotic pathway. Quantitative real-time PCR analysis showed that following the exposure of HepG2 cells to NiO NPs, the expression level of mRNA of apoptotic genes (bax and caspase-3) were up-regulated whereas the expression level of anti-apoptotic gene bcl-2 was down-regulated. Moreover, activity of caspase-3 enzyme was also higher in NiO NPs treated cells. To the best of our knowledge this is the first report demonstrating that NiO NPs caused cytotoxicity via ROS and induced apoptosis in HepG2 cells, which is likely to be mediated through bax/bcl-2 pathway. This work warrants careful assessment of Ni NPs before their commercial and industrial applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fluorophore-conjugated iron oxide nanoparticle labeling and analysis of engrafting human hematopoietic stem cells

DEFF Research Database (Denmark)

Maxwell, Dustin J; Bonde, Jesper; Hess, David A

2008-01-01

culture conditions to maintain viability without inducing terminal differentiation. In the current study, fluorescent molecules were covalently linked to dextran-coated iron oxide nanoparticles (Feridex) to characterize human HSC labeling to monitor the engraftment process. Conjugating fluorophores...... to the dextran coat for fluorescence-activated cell sorting purification eliminated spurious signals from nonsequestered nanoparticle contaminants. A short-term defined incubation strategy was developed that allowed efficient labeling of both quiescent and cycling HSC, with no discernable toxicity in vitro...

Synthesis, Characterization, and Cytotoxicity of Iron Oxide Nanoparticles

Directory of Open Access Journals (Sweden)

S. Kanagesan

2013-01-01

Full Text Available In order to study the response of human breast cancer cells' exposure to nanoparticle, iron oxide (α-Fe2O3 nanoparticles were synthesized by a simple low temperature combustion method using Fe(NO33·9H2O as raw material. X-ray diffraction studies confirmed that the resultant powders are pure α-Fe2O3. Transmission electron microscopy study revealed the spherical shape of the primary particles, and the size of the iron oxide nanoparticles is in the range of 19 nm. The magnetic hysteresis loops demonstrated that the sample exposed ferromagnetic behaviors with a relatively low coercivity. The cytotoxicity of α-Fe2O3 nanoparticle was also evaluated on human breast cancer cells to address the current deficient knowledge of cellular response to nanoparticle exposure.

Surface modification of PLGA nanoparticles to deliver nitric oxide to inhibit Escherichia coli growth

Energy Technology Data Exchange (ETDEWEB)

Reger, Nina A. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); Meng, Wilson S. [Division of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282 (United States); Gawalt, Ellen S., E-mail: gawalte@duq.edu [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219 (United States)

2017-04-15

Highlights: • Thin film functionalized PLGA nanoparticles were modified to release nitric oxide from an s-nitrosothiol donor. • The nitric oxide modified nanoparticles were bacteriostatic against Escherichia coli. • The nitric oxide modified nanoparticles increased the effectiveness of tetracycline against Escherichia coli. • The modified nitric oxide nanoparticles did not exhibit cytotoxic effects against fibroblasts. - Abstract: Polymer nanoparticles consisting of poly (DL-lactic-co-glycolic acid) were surface functionalized to deliver nitric oxide. These biodegradable and biocompatible nanoparticles were modified with an S-nitrosothiol molecule, S-nitrosocysteamine, as the nitric oxide delivery molecule. S-nitrosocysteamine was covalently immobilized on the nanoparticle surface using small organic molecule linkers and carbodiimide coupling. Nanoparticle size, zeta potential, and morphology were determined using dynamic light scattering and scanning electron microscopy, respectively. Subsequent attachment of the S-nitrosothiol resulted in a nitric oxide release of 37.1 ± 1.1 nmol per milligram of nanoparticles under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli culture growth by 31.8%, indicating that the nitric oxide donor was effective at releasing nitric oxide even after attachment to the nanoparticle surface. Combining the nitric oxide modified nanoparticles with tetracycline, a commonly prescribed antibiotic for E. coli infections, increased the effectiveness of the antibiotic by 87.8%, which allows for lower doses of antibiotics to be used in order to achieve the same effect. The functionalized nanoparticles were not cytotoxic to mouse fibroblasts.

Surface modification of PLGA nanoparticles to deliver nitric oxide to inhibit Escherichia coli growth

International Nuclear Information System (INIS)

Reger, Nina A.; Meng, Wilson S.; Gawalt, Ellen S.

2017-01-01

Highlights: • Thin film functionalized PLGA nanoparticles were modified to release nitric oxide from an s-nitrosothiol donor. • The nitric oxide modified nanoparticles were bacteriostatic against Escherichia coli. • The nitric oxide modified nanoparticles increased the effectiveness of tetracycline against Escherichia coli. • The modified nitric oxide nanoparticles did not exhibit cytotoxic effects against fibroblasts. - Abstract: Polymer nanoparticles consisting of poly (DL-lactic-co-glycolic acid) were surface functionalized to deliver nitric oxide. These biodegradable and biocompatible nanoparticles were modified with an S-nitrosothiol molecule, S-nitrosocysteamine, as the nitric oxide delivery molecule. S-nitrosocysteamine was covalently immobilized on the nanoparticle surface using small organic molecule linkers and carbodiimide coupling. Nanoparticle size, zeta potential, and morphology were determined using dynamic light scattering and scanning electron microscopy, respectively. Subsequent attachment of the S-nitrosothiol resulted in a nitric oxide release of 37.1 ± 1.1 nmol per milligram of nanoparticles under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli culture growth by 31.8%, indicating that the nitric oxide donor was effective at releasing nitric oxide even after attachment to the nanoparticle surface. Combining the nitric oxide modified nanoparticles with tetracycline, a commonly prescribed antibiotic for E. coli infections, increased the effectiveness of the antibiotic by 87.8%, which allows for lower doses of antibiotics to be used in order to achieve the same effect. The functionalized nanoparticles were not cytotoxic to mouse fibroblasts.

Zinc oxide nanoparticles induce apoptosis and autophagy in human ovarian cancer cells

Directory of Open Access Journals (Sweden)

Bai D

2017-09-01

. Finally, the Western blot analysis revealed upregulation of Bax, caspase-9, Rad51, γ-H2AX, p53, and LC3 and downregulation of Bcl-2. Conclusion: The study findings demonstrated that the ZnO NPs are able to induce significant cytotoxicity, apoptosis, and autophagy in human ovarian cells through reactive oxygen species generation and oxidative stress. Therefore, this study suggests that ZnO NPs are suitable and inherent anticancer agents due to their several favorable characteristic features including favorable band gap, electrostatic charge, surface chemistry, and potentiation of redox cycling cascades. Keywords: zinc oxide nanoparticles, human ovarian cancer cells SKOV3, mitochondrial membrane potential, apoptosis, DNA fragmentation, autophagy

Differential plasma protein binding to metal oxide nanoparticles

International Nuclear Information System (INIS)

Deng, Zhou J; Mortimer, Gysell; Minchin, Rodney F; Schiller, Tara; Musumeci, Anthony; Martin, Darren

2009-01-01

Nanoparticles rapidly interact with the proteins present in biological fluids, such as blood. The proteins that are adsorbed onto the surface potentially dictate the biokinetics of the nanomaterials and their fate in vivo. Using nanoparticles with different sizes and surface characteristics, studies have reported the effects of physicochemical properties on the composition of adsorbed plasma proteins. However, to date, few studies have been conducted focusing on the nanoparticles that are commonly exposed to the general public, such as the metal oxides. Using previously established ultracentrifugation approaches, two-dimensional gel electrophoresis and mass spectrometry, the current study investigated the binding of human plasma proteins to commercially available titanium dioxide, silicon dioxide and zinc oxide nanoparticles. We found that, despite these particles having similar surface charges in buffer, they bound different plasma proteins. For TiO 2 , the shape of the nanoparticles was also an important determinant of protein binding. Agglomeration in water was observed for all of the nanoparticles and both TiO 2 and ZnO further agglomerated in biological media. This led to an increase in the amount and number of different proteins bound to these nanoparticles. Proteins with important biological functions were identified, including immunoglobulins, lipoproteins, acute-phase proteins and proteins involved in complement pathways and coagulation. These results provide important insights into which human plasma proteins bind to particular metal oxide nanoparticles. Because protein absorption to nanoparticles may determine their interaction with cells and tissues in vivo, understanding how and why plasma proteins are adsorbed to these particles may be important for understanding their biological responses.

Magnetic properties of iron oxide nanoparticles prepared by seeded-growth route

International Nuclear Information System (INIS)

Espinosa, A.; Muñoz-Noval, A.; García-Hernández, M.; Serrano, A.; Jiménez de la Morena, J.; Figuerola, A.; Quarta, A.; Pellegrino, T.; Wilhelm, C.; García, M. A.

2013-01-01

In this work we investigate the magnetic properties of iron oxide nanoparticles obtained by two-step synthesis (seeded-growth route) with sizes that range from 6 to 18 nm. The initial seeds result monocrystalline and exhibit ferromagnetic behavior with low saturation field. The subsequent growth of a shell enhances the anisotropy inducing magnetic frustration, and, consequently, reducing its magnetization. This increase in anisotropy occurs suddenly at a certain size (∼10 nm). Electronic and structural analysis with X-ray absorption spectroscopy indicates a step reduction in the oxidation state as the particle reaches 10 nm size while keeping its overall structure in spite of the magnetic polydispersity. The formation of antiphase magnetic boundaries due to island percolation in the growing shells is hypothesized to be the mechanism responsible of the magnetic behavior, as a direct consequence of the two-step synthesis route of the nanoparticles.

Surface modification of promising cerium oxide nanoparticles for nanomedicine applications

KAUST Repository

Nanda, Himansu Sekhar

2016-11-14

Cerium oxide nanoparticles (CNPs) or nanoceria have emerged as a potential nanomedicine for the treatment of several diseases such as cancer. CNPs have a natural tendency to aggregate or agglomerate in their bare state, which leads to sedimentation in a biological environment. Since the natural biological environment is essentially aqueous, nanoparticle surface modification using suitable biocompatible hydrophilic chemical moieties is highly desirable to create effective aqueous dispersions. In this report, (6-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-hexyl)triethoxysilane was used as a functional, biocompatible organosilane to modify the surface of CNPs to produce promising nanoparticles which open substantial therapeutic avenues. The surface modified nanoparticles were produced in situ via an ammonia-induced ethylene glycol-assisted precipitation method and were characterized using complimentary characterization techniques. The interaction between the functional moiety and the nanoparticle was studied using powerful cross polarization/magic angle sample spinning solid state nuclear magnetic resonance spectroscopy. The surface-modified nanoparticles were extremely small and demonstrated a significant improvement in aqueous dispersibility. Moreover, the existence of a strong ionic coordination between the functional moiety and the surface of the nanoparticle was realised, indicating that the surface modified nanoceria are stable and that the nanoparticles should demonstrate an enhanced circulation time in a biological environment. The surface modification approach should be promising for the production of CNPs for nanomedicine applications. © The Royal Society of Chemistry.

Eupafolin nanoparticles protect HaCaT keratinocytes from particulate matter-induced inflammation and oxidative stress

Directory of Open Access Journals (Sweden)

Lin ZC

2016-08-01

applications. To address these issues, we successfully synthesized a eupafolin nanoparticle delivery system (ENDS. Our findings showed that ENDS could overcome the physicochemical drawbacks of raw eupafolin with respect to water solubility and skin penetration, through reduction of particle size and formation of an amorphous state with hydrogen bonding. Moreover, ENDS was superior to raw eupafolin in attenuating PM-induced oxidative stress and inflammation in HaCaT keratinocytes, by mediating the antioxidant pathway (decreased reactive oxygen species production and nicotinamide adenine dinucleotide phosphate oxidase activity and anti-inflammation pathway (decreased cyclooxygenase-2 expression and prostaglandin E2 production through downregulation of mitogen-activated protein kinase and nuclear factor-κB signaling. In summary, ENDS shows better antioxidant and anti-inflammatory activities than raw eupafolin through improvement of water solubility and skin penetration. Therefore, ENDS may potentially be used as a medicinal drug and/or cosmeceutical product to prevent PM-induced skin inflammation. Keywords: eupafolin, nanoparticles, particulate matter, oxidative stress, cyclooxygenase-2, keratinocytes

Manganese oxide nanoparticles, methods and applications

Science.gov (United States)

Abruna, Hector D.; Gao, Jie; Lowe, Michael A.

2017-08-29

Manganese oxide nanoparticles having a chemical composition that includes Mn.sub.3O.sub.4, a sponge like morphology and a particle size from about 65 to about 95 nanometers may be formed by calcining a manganese hydroxide material at a temperature from about 200 to about 400 degrees centigrade for a time period from about 1 to about 20 hours in an oxygen containing environment. The particular manganese oxide nanoparticles with the foregoing physical features may be used within a battery component, and in particular an anode within a lithium battery to provide enhanced performance.

The detection of HBV DNA with gold-coated iron oxide nanoparticle gene probes

International Nuclear Information System (INIS)

Xi Dong; Luo Xiaoping; Lu Qianghua; Yao Kailun; Liu Zuli; Ning Qin

2008-01-01

Gold-coated iron oxide nanoparticle Hepatitis B virus (HBV) DNA probes were prepared, and their application for HBV DNA measurement was studied. Gold-coated iron oxide nanoparticles were prepared by the citrate reduction of tetra-chloroauric acid in the presence of iron oxide nanoparticles which were added as seeds. With a fluorescence-based method, the maximal surface coverage of hexaethiol 30-mer oligonucleotides and the maximal percentage of hybridization strands on gold-coated iron oxide nanoparticles were (120 ± 8) oligonucleotides per nanoparticle, and (14 ± 2%), respectively, which were comparable with those of (132 ± 10) and (22 ± 3%) in Au nanoparticle groups. Large network aggregates were formed when gold-coated iron oxide nanoparticle HBV DNA gene probe was applied to detect HBV DNA molecules as evidenced by transmission electron microscopy and the high specificity was verified by blot hybridization. Our results further suggested that detecting DNA with iron oxide nanoparticles and magnetic separator was feasible and might be an alternative effective method

Structure of Oxide Nanoparticles in Fe-16Cr MA/ODS Ferritic Steel

Energy Technology Data Exchange (ETDEWEB)

Hsiung, L; Fluss, M; Kimura, A

2010-04-06

Oxide nanoparticles in Fe-16Cr ODS ferritic steel fabricated by mechanical alloying (MA) method have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. A partial crystallization of oxide nanoparticles was frequently observed in as-fabricated ODS steel. The crystal structure of crystalline oxide particles is identified to be mainly Y{sub 4}Al{sub 2}O{sub 9} (YAM) with a monoclinic structure. Large nanoparticles with a diameter larger than 20 nm tend to be incoherent and have a nearly spherical shape, whereas small nanoparticles with a diameter smaller than 10 nm tend to be coherent or semi-coherent and have faceted boundaries. The oxide nanoparticles become fully crystallized after prolonged annealing at 900 C. These results lead us to propose a three-stage formation mechanism of oxide nanoparticles in MA/ODS steels.

Safety assessment of chronic oral exposure to iron oxide nanoparticles

International Nuclear Information System (INIS)

Chamorro, Susana; Vaquero, María Pilar; Brenes, Agustín; Gutiérrez, Lucía; Salas, Gorka; Luengo, Yurena; Verdoy, Dolores; José Teran, Francisco

2015-01-01

Iron oxide nanoparticles with engineered physical and biochemical properties are finding a rapidly increasing number of biomedical applications. However, a wide variety of safety concerns, especially those related to oral exposure, still need to be addressed for iron oxide nanoparticles in order to reach clinical practice. Here, we report on the effects of chronic oral exposure to low doses of γ-Fe 2 O 3 nanoparticles in growing chickens. Animal observation, weight, and diet intake reveal no adverse signs, symptoms, or mortality. No nanoparticle accumulation was observed in liver, spleen, and duodenum, with feces as the main excretion route. Liver iron level and duodenal villi morphology reflect the bioavailability of the iron released from the partial transformation of γ-Fe 2 O 3 nanoparticles in the acid gastric environment. Duodenal gene expression studies related to the absorption of iron from γ-Fe 2 O 3 nanoparticles indicate the enhancement of a ferric over ferrous pathway supporting the role of mucins. Our findings reveal that oral administration of iron oxide nanoparticles is a safe route for drug delivery at low nanoparticle doses. (paper)

Synthesis, characterisation and electrochemical evaluation of reduced graphene oxide modified antimony nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Silwana, Bongiwe; Horst, Charlton van der [Natural Resources and the Environment (NRE), Council for Scientific and Industrial Research (CSIR), Stellenbosch 7600 (South Africa); SensorLab, Department of Chemistry, University of the Western Cape, Bellville 7535 (South Africa); Iwuoha, Emmanuel [SensorLab, Department of Chemistry, University of the Western Cape, Bellville 7535 (South Africa); Somerset, Vernon, E-mail: vsomerset@csir.co.za [Natural Resources and the Environment (NRE), Council for Scientific and Industrial Research (CSIR), Stellenbosch 7600 (South Africa)

2015-10-01

This paper demonstrates some aspects on the synthesis and characterisation of nanoparticles of metallic alloys using polyvinyl alcohol as a stabiliser, which combines high surface area and superior hybrid properties. The present experimental design was to synthesise a nanocomposite of reduced graphene oxide and antimony nanoparticles to be used as thin films for macro- and micro-carbon electrodes for enhancing sensing of different toxic metal pollutants in the environment. The synthetic process of reduced graphene oxide was done using the modified Hummers method while antimony pentachloride was reduced with sodium borohydride into nanoparticles of antimony using polyvinyl-alcohol as a stabiliser. The systematic investigation of morphology was done by scanning electron microscopy and high resolution-transmission electron microscope, which revealed the synthesis of a product, consists of reduced graphene oxide antimony nanoparticles. The electrochemical behaviour of the reduced graphene oxide antimony nanoparticles coated on a glassy carbon electrode was performed using voltammetric and impedance techniques. Electrochemical impedance measurements showed that the overall resistance, including the charge–transfer resistance, was smaller with reduced graphene oxide antimony nanoparticles than reduced graphene oxide and antimony nanoparticles, on their own. Evaluation of the reduced graphene oxide antimony nanoparticle sensor in the stripping voltammetry has shown a linear working range for concentration of platinum (II) between 6.0 × 10{sup −6}–5.4 × 10{sup −5} μg L{sup −1} with limit of detection of 6 × 10{sup −6} μg L{sup −1} (signal-to-noise ratio = 3), which is below the World Health Organisation guidelines for freshwater. - Highlights: • Reduced graphene oxide modified antimony nanoparticles were chemically synthesised. • TEM results show rGO-Sb nanoparticles with a diameter range of between 2 and 20 nm. • Impedance results confirm

The interfacial orientation relationship of oxide nanoparticles in a hafnium-containing oxide dispersion-strengthened austenitic stainless steel

Energy Technology Data Exchange (ETDEWEB)

Miao, Yinbin, E-mail: miao2@illinois.edu [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Mo, Kun [Nuclear Engineering Division, Argonne National Laboratory, Lemont, IL 60493 (United States); Cui, Bai [Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588 (United States); Department of Material Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Chen, Wei-Ying [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Miller, Michael K.; Powers, Kathy A. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States); McCreary, Virginia; Gross, David [Department of Material Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Almer, Jonathan [X-ray Science Division, Argonne National Laboratory, Lemont, IL 60493 (United States); Robertson, Ian M. [Department of Material Science and Engineering, University of Wisconsin-Madison, Madison, WA 53706 (United States); Department of Material Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Stubbins, James F. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

2015-03-15

This work reports comprehensive investigations on the orientation relationship of the oxide nanoparticles in a hafnium-containing austenitic oxide dispersion-strengthened 316 stainless steel. The phases of the oxide nanoparticles were determined by a combination of scanning transmission electron microscopy–electron dispersive X-ray spectroscopy, atom probe tomography and synchrotron X-ray diffraction to be complex Y–Ti–Hf–O compounds with similar crystal structures, including bixbyite Y{sub 2}O{sub 3}, fluorite Y{sub 2}O{sub 3}–HfO{sub 2} solid solution and pyrochlore (or fluorite) Y{sub 2}(Ti,Hf){sub 2−x}O{sub 7−x}. High resolution transmission electron microscopy was used to characterize the particle–matrix interfaces. Two different coherency relationships along with one axis-parallel relation between the oxide nanoparticles and the steel matrix were found. The size of the nanoparticles significantly influences the orientation relationship. The results provide insight into the relationship of these nanoparticles with the matrix, which has implications for interpreting material properties as well as responses to radiation. - Highlights: • The oxide nanoparticles in a hafnium-containing austenitic ODS were characterized. • The nanoparticles are Y–Hf–Ti–O enriched phases according to APT and STEM–EDS. • Two coherency and an axis-parallel orientation relationships were found by HR-TEM. • Particle size has a prominent effect on the orientation relationship (OR). • Formation mechanism of the oxide nanoparticles was discussed based on the ORs.

Synthesis and optical properties of Au decorated colloidal tungsten oxide nanoparticles

International Nuclear Information System (INIS)

Tahmasebi, Nemat; Mahdavi, Seyed Mohammad

2015-01-01

Highlights: • Tungsten oxide nanoparticles were prepared by pulsed laser ablation (PLA). • A very fine metallic Au particles or coating are decorated on the surface of tungsten oxide nanoparticles. • UV–Vis spectroscopy shows an absorption peak at ∼530 nm which is due to SPR effect of gold. • After exposing to hydrogen gas, Au/WO_3 colloidal nanoparticles show excellent gasochromic coloring. - Abstract: In this study, colloidal tungsten oxide nanoparticles were fabricated by pulsed laser ablation of tungsten target using the first harmonic of a Nd:YAG laser (1064 nm) in deionized water. After ablation, a 0.33 g/lit HAuCl_4 aqueous solution was added into as-prepared colloidal nanoparticles. In this process, Au"3"+ ions were reduced to decorate gold metallic state (Au"0) onto colloidal tungsten oxide nanoparticles surface. The morphology and chemical composition of the synthesized nanoparticles were studied by AFM, XRD, TEM and XPS techniques. UV–Vis analysis reveals a distinct absorption peak at ∼530 nm. This peak can be attributed to the surface plasmon resonance (SPR) of Au and confirms formation of gold state. Moreover, X-ray photoelectron spectroscopy reveals that Au ions’ reduction happens after adding HAuCl_4 solution into as-prepared colloidal tungsten oxide nanoparticles. Transmission electron microscope shows that an Au shell has been decorated onto colloidal WO_3 nanoparticles. Noble metal decorated tungsten oxide nanostructure could be an excellent candidate for photocatalysis, gas sensing and gasochromic applications. Finally, the gasochromic behavior of the synthesized samples was investigated by H_2 and O_2 gases bubbling into the produced colloidal Au/WO_3 nanoparticles. Synthesized colloidal nanoparticles show excellent coloration contrast (∼80%) through NIR spectra.

Promising iron oxide-based magnetic nanoparticles in biomedical engineering.

Science.gov (United States)

Tran, Phuong Ha-Lien; Tran, Thao Truong-Dinh; Vo, Toi Van; Lee, Beom-Jin

2012-12-01

For the past few decades biomedical engineering has imprinted its significant impact on the map of science through its wide applications on many other fields. An important example obviously proving this fact is the versatile application of magnetic nanoparticles in theranostics. Due to preferable properties such as biocompatibility, non-toxicity compared to other metal derivations, iron oxide-based magnetic nanoparticles was chosen to be addressed in this review. Aim of this review is to give the readers a whole working window of these magnetic nanoparticles in the current context of science. Thus, preparation of magnetic iron oxide nanoparticles with the so-far techniques, methods of characterizing the nanoparticles as well as their most recent biomedical applications will be stated.

Cerium oxide nanoparticles protect rodent lungs from hypobaric hypoxia-induced oxidative stress and inflammation

Directory of Open Access Journals (Sweden)

Arya A

2013-11-01

Full Text Available Aditya Arya,1 Niroj Kumar Sethy,1 Sushil Kumar Singh,2 Mainak Das,3 Kalpana Bhargava1 1Peptide and Proteomics Division, Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Delhi, 2Functional Materials Division, Solid State Physics Laboratory, Defence Research and Development Organization, Delhi, 3Biological Science and Bioengineering, Indian Institute of Technology, Kanpur, Uttar Pradesh, India Background: Cerium oxide nanoparticles (nanoceria are effective at quenching reactive oxygen species (ROS in cell culture and animal models. Although nanoceria reportedly deposit in lungs, their efficacy in conferring lung protection during oxidative stress remains unexplored. Thus, the study evaluated the protective efficacy of nanoceria in rat lung tissue during hypobaric hypoxia. Methods: A total of 48 animals were randomly divided into four equal groups (control [C], nanoceria treated [T], hypoxia [H], and nanoceria treated plus hypoxia [T+H]. Animals were injected intraperitoneally with either a dose of 0.5 µg/kg body weight/week of nanoceria (T and T+H groups or vehicle (C and H groups for 5 weeks. After the final dose, H and T+H animals were challenged with hypobaric hypoxia, while C and T animals were maintained at normoxia. Lungs were isolated and homogenate was obtained for analysis of ROS, lipid peroxidation, glutathione, protein carbonylation, and 4-hydroxynonenal-adduct formation. Plasma was used for estimating major inflammatory cytokines using enzyme-linked immunosorbent assay. Intact lung tissues were fixed and both transmission electron microscopy and histopathological examinations were carried out separately for detecting internalization of nanoparticles as well as altered lung morphology. Results: Spherical nanoceria of 7–10 nm diameter were synthesized using a microemulsion method, and the lung protective efficacy of the nanoceria evaluated during hypobaric hypoxia. With repeated

Protein capped nanosilver free radical oxidation: role of biomolecule capping on nanoparticle colloidal stability and protein oxidation.

Science.gov (United States)

Ahumada, Manuel; Bohne, Cornelia; Oake, Jessy; Alarcon, Emilio I

2018-05-03

We studied the effect of human serum albumin protein capped spherical nanosilver on the nanoparticle stability upon peroxyl radical oxidation. The nanoparticle-protein composite is less prone to oxidation compared to the individual components. However, higher concentrations of hydrogen peroxide were formed in the nanoparticle-protein system.

Antibacterial effects of zinc oxide nanoparticles on Escherichia coli ...

African Journals Online (AJOL)

To study the antibacterial mechanisms, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to observe morphological changes of E. coli K88 treated with 0.8 μg/ml zinc oxide nanoparticles. The results reveal that zinc oxide nanoparticles could damage cell membranes, lead to leakage of ...

Dextran and Polymer Polyethylene Glycol (PEG Coating Reduce Both 5 and 30 nm Iron Oxide Nanoparticle Cytotoxicity in 2D and 3D Cell Culture

Directory of Open Access Journals (Sweden)

Alisa Morss Clyne

2012-05-01

Full Text Available Superparamagnetic iron oxide nanoparticles are widely used in biomedical applications, yet questions remain regarding the effect of nanoparticle size and coating on nanoparticle cytotoxicity. In this study, porcine aortic endothelial cells were exposed to 5 and 30 nm diameter iron oxide nanoparticles coated with either the polysaccharide, dextran, or the polymer polyethylene glycol (PEG. Nanoparticle uptake, cytotoxicity, reactive oxygen species (ROS formation, and cell morphology changes were measured. Endothelial cells took up nanoparticles of all sizes and coatings in a dose dependent manner, and intracellular nanoparticles remained clustered in cytoplasmic vacuoles. Bare nanoparticles in both sizes induced a more than 6 fold increase in cell death at the highest concentration (0.5 mg/mL and led to significant cell elongation, whereas cell viability and morphology remained constant with coated nanoparticles. While bare 30 nm nanoparticles induced significant ROS formation, neither 5 nm nanoparticles (bare or coated nor 30 nm coated nanoparticles changed ROS levels. Furthermore, nanoparticles were more toxic at lower concentrations when cells were cultured within 3D gels. These results indicate that both dextran and PEG coatings reduce nanoparticle cytotoxicity, however different mechanisms may be important for different size nanoparticles.

After oxidation, zinc nanoparticles lose their ability to enhance responses to odorants.

Science.gov (United States)

Hagerty, Samantha; Daniels, Yasmine; Singletary, Melissa; Pustovyy, Oleg; Globa, Ludmila; MacCrehan, William A; Muramoto, Shin; Stan, Gheorghe; Lau, June W; Morrison, Edward E; Sorokulova, Iryna; Vodyanoy, Vitaly

2016-12-01

Electrical responses of olfactory sensory neurons to odorants were examined in the presence of zinc nanoparticles of various sizes and degrees of oxidation. The zinc nanoparticles were prepared by the underwater electrical discharge method and analyzed by atomic force microscopy and X-ray photoelectron spectroscopy. Small (1.2 ± 0.3 nm) zinc nanoparticles significantly enhanced electrical responses of olfactory neurons to odorants. After oxidation, however, these small zinc nanoparticles were no longer capable of enhancing olfactory responses. Larger zinc oxide nanoparticles (15 nm and 70 nm) also did not modulate responses to odorants. Neither zinc nor zinc oxide nanoparticles produced olfactory responses when added without odorants. The enhancement of odorant responses by small zinc nanoparticles was explained by the creation of olfactory receptor dimers initiated by small zinc nanoparticles. The results of this work will clarify the mechanisms for the initial events in olfaction, as well as to provide new ways to alleviate anosmia related to the loss of olfactory receptors.

Reduced graphene oxide and inorganic nanoparticles composites – synthesis and characterization

Directory of Open Access Journals (Sweden)

Onyszko Magdalena

2015-12-01

Full Text Available Graphene – novel 2D material, which possesses variety of fascinating properties, can be considered as a convenient support material for the nanoparticles. In this work various methods of synthesis of reduced graphene oxide with metal or metal oxide nanoparticles will be presented. The hydrothermal approach for deposition of platinum, palladium and zirconium dioxide nanoparticles in ethylene glycol/water solution was applied. Here, platinum/reduced graphene oxide (Pt/RGO, palladium/reduced graphene oxide (Pd/RGO and zirconium dioxide/reduced graphene oxide (ZrO2/RGO nanocomposites were prepared. Additionally, manganese dioxide/reduced graphene oxide nanocomposite (MnO2/RGO was synthesized in an oleic-water interface. The obtained nanocomposites were investigated by transmission electron microscopy (TEM, X-ray diffraction analysis (XRD, Raman spectroscopy and thermogravimetric analysis (TGA. The results shows that GO can be successfully used as a template for direct synthesis of metal or metal oxide nanoparticles on its surface with a homogenous distribution.

Surface interactions affect the toxicity of engineered metal oxide nanoparticles toward Paramecium.

Science.gov (United States)

Li, Kungang; Chen, Ying; Zhang, Wen; Pu, Zhichao; Jiang, Lin; Chen, Yongsheng

2012-08-20

To better understand the potential impacts of engineered metal oxide nanoparticles (NPs) in the ecosystem, we investigated the acute toxicity of seven different types of engineered metal oxide NPs against Paramecium multimicronucleatum, a ciliated protozoan, using the 48 h LC(50) (lethal concentration, 50%) test. Our results showed that the 48 h LC(50) values of these NPs to Paramecium ranged from 0.81 (Fe(2)O(3) NPs) to 9269 mg/L (Al(2)O(3) NPs); their toxicity to Paramecium increased as follows: Al(2)O(3) Paramecium; this implies that metal oxide NPs with strong association with the cell surface might induce more severe cytotoxicity in unicellular organisms.

Oxide nanoparticles in an Al-alloyed oxide dispersion strengthened steel: crystallographic structure and interface with ferrite matrix

DEFF Research Database (Denmark)

Zhang, Zhenbo; Pantleon, Wolfgang

2017-01-01

Oxide nanoparticles are quintessential for ensuring the extraordinary properties of oxide dispersion strengthened (ODS) steels. In this study, the crystallographic structure of oxide nanoparticles, and their interface with the ferritic steel matrix in an Al-alloyed ODS steel, i.e. PM2000, were...

Anti-oxidant effect of gold nanoparticles restrains hyperglycemic conditions in diabetic mice

Directory of Open Access Journals (Sweden)

Eom SooHyun

2010-07-01

Full Text Available Abstract Background Oxidative stress is imperative for its morbidity towards diabetic complications, where abnormal metabolic milieu as a result of hyperglycemia, leads to the onset of several complications. A biological antioxidant capable of inhibiting oxidative stress mediated diabetic progressions; during hyperglycemia is still the need of the era. The current study was performed to study the effect of biologically synthesized gold nanoparticles (AuNPs to control the hyperglycemic conditions in streptozotocin induced diabetic mice. Results The profound control of AuNPs over the anti oxidant enzymes such as GSH, SOD, Catalase and GPx in diabetic mice to normal, by inhibition of lipid peroxidation and ROS generation during hyperglycemia evidence their anti-oxidant effect during hyperglycemia. The AuNPs exhibited an insistent control over the blood glucose level, lipids and serum biochemical profiles in diabetic mice near to the control mice provokes their effective role in controlling and increasing the organ functions for better utilization of blood glucose. Histopathological and hematological studies revealed the non-toxic and protective effect of the gold nanoparticles over the vital organs when administered at dosage of 2.5 mg/kilogram.body.weight/day. ICP-MS analysis revealed the biodistribution of gold nanoparticles in the vital organs showing accumulation of AuNPs in the spleen comparatively greater than other organs. Conclusion The results obtained disclose the effectual role of AuNPs as an anti-oxidative agent, by inhibiting the formation of ROS, scavenging free radicals; thus increasing the anti-oxidant defense enzymes and creating a sustained control over hyperglycemic conditions which consequently evoke the potential of AuNPs as an economic therapeutic remedy in diabetic treatments and its complications.

Biocompatibility of chitosan-coated iron oxide nanoparticles with osteoblast cells

Directory of Open Access Journals (Sweden)

Shi S

2012-10-01

Full Text Available Si-Feng Shi,1 Jing-Fu Jia,2 Xiao-Kui Guo,3 Ya-Ping Zhao,2 De-Sheng Chen,1 Yong-Yuan Guo,1 Tao Cheng,1 Xian-Long Zhang11Department of Orthopedic Surgery, Shanghai Sixth People’s Hospital, School of Medicine, 2School of Chemistry and Chemical Technology, 3Department of Medical Microbiology and Parasitology, School of Medicine, Shanghai Jiao Tong University Shanghai, ChinaBackground: Bone disorders (including osteoporosis, loosening of a prosthesis, and bone infections are of great concern to the medical community and are difficult to cure. Therapies are available to treat such diseases, but all have drawbacks and are not specifically targeted to the site of disease. Chitosan is widely used in the biomedical community, including for orthopedic applications. The aim of the present study was to coat chitosan onto iron oxide nanoparticles and to determine its effect on the proliferation and differentiation of osteoblasts.Methods: Nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, x-ray diffraction, zeta potential, and vibrating sample magnetometry. Uptake of nanoparticles by osteoblasts was studied by transmission electron microscopy and Prussian blue staining. Viability and proliferation of osteoblasts were measured in the presence of uncoated iron oxide magnetic nanoparticles or those coated with chitosan. Lactate dehydrogenase, alkaline phosphatase, total protein synthesis, and extracellular calcium deposition was studied in the presence of the nanoparticles.Results: Chitosan-coated iron oxide nanoparticles enhanced osteoblast proliferation, decreased cell membrane damage, and promoted cell differentiation, as indicated by an increase in alkaline phosphatase and extracellular calcium deposition. Chitosan-coated iron oxide nanoparticles showed good compatibility with osteoblasts.Conclusion: Further research is necessary to optimize magnetic nanoparticles for the treatment of bone disease

Ceriodaphnia dubia as a potential bio-indicator for assessing acute aluminum oxide nanoparticle toxicity in fresh water environment.

Directory of Open Access Journals (Sweden)

Sunandan Pakrashi

Full Text Available Growing nanomaterials based consumer applications have raised concerns about their potential release into the aquatic ecosystems and the consequent toxicological impacts. So environmental monitoring of the nanomaterials in aqueous systems becomes imperative. The current study reveals the potential of Ceriodaphnia dubia (C. dubia as a bio-indicator for aluminum oxide nanoparticles in a fresh water aquatic ecosystem where it occupies an important ecological niche as a primary consumer. This study aims to investigate the aluminium oxide nanoparticle induced acute toxicity on Ceriodaphnia dubia in a freshwater system. The bioavailability of the aluminum oxide nanoparticles has been studied with respect to their aggregation behavior in the system and correlated with the toxicity endpoints. The oxidative stress generated by the particles contributed greatly toward their toxicity. The crucial role of leached aluminium ion mediated toxicity in the later phases (48 h and 72 h in conjunction with the effects from the nano-sized particles in the initial phases (24 h puts forth the dynamics of nanotoxicity in the test system. The internalization of nanoparticles (both gross and systemic uptake as substantiated through the transmission electron microscopy (TEM and inductively coupled plasma optical emission spectral (ICP-OES analysis was another major contributor toward acute toxicity. Concluding the present study, Ceriodaphnia dubia can be a promising candidate for bio-monitoring the aluminium oxide nanoparticles in a fresh water system.

Chromium Elimination from Water by use of Iron Oxide Nanoparticles Absorbents

Directory of Open Access Journals (Sweden)

S Shokraei

2014-09-01

Results: results showed that best absorbent is soil absorbent and iron oxide nanoparticles, with maximum removal percent equal to 96.2%. Also best turnover was obtained from 8837 ppm of primary concentration of heavy metal. In other hand, in other experiments that used from iron oxide nanoparticles, adding of nanoparticles caused to increase in chrome absorption and conversion of Cr6+ to Cr3+. Conclusion: with use of the results of this study can be said that Combining of iron oxide nanoparticles with chrome removal filters can be convert Cr6+ to Cr3+, and process turnover will increased.

Efficient One-Pot Synthesis of Colloidal Zirconium Oxide Nanoparticles for High-Refractive-Index Nanocomposites.

Science.gov (United States)

Liu, Chao; Hajagos, Tibor Jacob; Chen, Dustin; Chen, Yi; Kishpaugh, David; Pei, Qibing

2016-02-01

Zirconium oxide nanoparticles are promising candidates for optical engineering, photocatalysis, and high-κ dielectrics. However, reported synthetic methods for the colloidal zirconium oxide nanoparticles use unstable alkoxide precursors and have various other drawbacks, limiting their wide application. Here, we report a facile one-pot method for the synthesis of colloidally stable zirconium oxide nanoparticles. Using a simple solution of zirconium trifluoroacetate in oleylamine, highly stable zirconium oxide nanoparticles have been synthesized with high yield, following a proposed amidization-assisted sol-gel mechanism. The nanoparticles can be readily dispersed in nonpolar solvents, forming a long-term stable transparent solution, which can be further used to fabricate high-refractive-index nanocomposites in both monolith and thin-film forms. In addition, the same method has also been extended to the synthesis of titanium oxide nanoparticles, demonstrating its general applicability to all group IVB metal oxide nanoparticles.

Cu-Ag core–shell nanoparticles with enhanced oxidation stability for printed electronics

International Nuclear Information System (INIS)

Lee, Changsoo; Kim, Na Rae; Koo, Jahyun; Lee, Yung Jong; Lee, Hyuck Mo

2015-01-01

In this work, we synthesized uniform Cu–Ag core–shell nanoparticles using a facile two-step process that consists of thermal decomposition and galvanic displacement methods. The core–shell structure of these nanoparticles was confirmed through characterization using transmission electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction. Furthermore, we investigated the oxidation stability of the Cu–Ag core–shell nanoparticles in detail. Both qualitative and quantitative x-ray photoelectron spectroscopy analyses confirm that the Cu–Ag core–shell nanoparticles have considerably higher oxidation stability than Cu nanoparticles. Finally, we formulated a conductive ink using the synthesized nanoparticles and coated it onto glass substrates. Following the sintering process, we compared the resistivity of the Cu–Ag core–shell nanoparticles with that of the Cu nanoparticles. The results of this study clearly show that the Cu–Ag core–shell nanoparticles can potentially be used as an alternative to Ag nanoparticles because of their superior oxidation stability and electrical properties. (paper)

Toxicity of superparamagnetic iron oxide nanoparticles: Research strategies and implications for nanomedicine

International Nuclear Information System (INIS)

Li Lei; Jiang Ling-Ling; Zeng Yun; Liu Gang

2013-01-01

Superparamagnetic iron oxide nanoparticles (SPIONs) are one of the most versatile and safe nanoparticles in a wide variety of biomedical applications. In the past decades, considerable efforts have been made to investigate the potential adverse biological effects and safety issues associated with SPIONs, which is essential for the development of next-generation SPIONs and for continued progress in translational research. In this mini review, we summarize recent developments in toxicity studies on SPIONs, focusing on the relationship between the physicochemical properties of SPIONs and their induced toxic biological responses for a better toxicological understanding of SPIONs. (topical review - magnetism, magnetic materials, and interdisciplinary research)

ICAM-1 targeted catalase encapsulated PLGA-b-PEG nanoparticles against vascular oxidative stress.

Science.gov (United States)

Sari, Ece; Tunc-Sarisozen, Yeliz; Mutlu, Hulya; Shahbazi, Reza; Ucar, Gulberk; Ulubayram, Kezban

2015-01-01

Targeted delivery of therapeutics is the favourable idea, whereas it is possible to distribute the therapeutically active drug molecule only to the site of action. For this purpose, in this study, catalase encapsulated poly(D,L-lactide-co-glycolide)-block-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles were developed and an endothelial target molecule (anti-ICAM-1) was conjugated to this carrier system in order to decrease the oxidative stress level in the target site. According to the enzymatic activity results, initial catalase activity of nanoparticles was increased from 27.39 U/mg to up to 45.66 U/mg by adding 5 mg/mL bovine serum albumin (BSA). After 4 h, initial catalase activity was preserved up to 46.98% while free catalase retained less than 4% of its activity in proteolytic environment. Furthermore, FITC labelled anti-ICAM-1 targeted catalase encapsulated nanoparticles (anti-ICAM-1/CatNPs) were rapidly taken up by cultured endothelial cells and concomitantly endothelial cells were resistant to H2O2 induced oxidative impairment.

Viscous properties of aluminum oxide nanotubes and aluminium oxide nanoparticles - silicone oil suspensions

Science.gov (United States)

Thapa, Ram; French, Steven; Delgado, Adrian; Ramos, Carlos; Gutierrez, Jose; Chipara, Mircea; Lozano, Karen

2010-03-01

Electrorheological (ER) fluids consisting of γ-aluminum oxide nanotubes and γ-aluminum oxide nanoparticles dispersed within silicone oil were prepared. The relationship between shear stress and shear rate was measured and theoretically simulated by using an extended Bingham model for both the rheological and electrorheological features of these systems. Shear stress and viscosity showed a sharp increase for the aluminum oxide nanotubes suspensions subjected to applied electric fields whereas aluminum oxide nanoparticles suspensions showed a moderate change. It was found that the transition from liquid to solid state (mediated by the applied electric field) can be described by a power law and that for low applied voltages the relationship is almost linear.

Role of epithelial-mesenchymal transition (EMT) and fibroblast function in cerium oxide nanoparticles-induced lung fibrosis

International Nuclear Information System (INIS)

Ma, Jane; Bishoff, Bridget; Mercer, R.R.; Barger, Mark; Schwegler-Berry, Diane; Castranova, Vincent

2017-01-01

The emission of cerium oxide nanoparticles (CeO 2 ) from diesel engines, using cerium compounds as a catalyst to lower the diesel exhaust particles, is a health concern. We have previously shown that CeO 2 induced pulmonary inflammation and lung fibrosis. The objective of the present study was to investigate the modification of fibroblast function and the role of epithelial-mesenchymal transition (EMT) in CeO 2 -induced fibrosis. Male Sprague-Dawley rats were exposed to CeO 2 (0.15 to 7 mg/kg) by a single intratracheal instillation and sacrificed at various times post-exposure. The results show that at 28 days after CeO 2 (3.5 mg/kg) exposure, lung fibrosis was evidenced by increased soluble collagen in bronchoalveolar lavage fluid, elevated hydroxyproline content in lung tissues, and enhanced sirius red staining for collagen in the lung tissue. Lung fibroblasts and alveolar type II (ATII) cells isolated from CeO 2 -exposed rats at 28 days post-exposure demonstrated decreasing proliferation rate when compare to the controls. CeO 2 exposure was cytotoxic and altered cell function as demonstrated by fibroblast apoptosis and aggregation, and ATII cell hypertrophy and hyperplasia with increased surfactant. The presence of stress fibers, expressed as α-smooth muscle actin (SMA), in CeO 2 -exposed fibroblasts and ATII cells was significantly increased compared to the control. Immunohistofluorescence analysis demonstrated co-localization of TGF-β or α-SMA with prosurfactant protein C (SPC)-stained ATII cells. These results demonstrate that CeO 2 exposure affects fibroblast function and induces EMT in ATII cells that play a role in lung fibrosis. These findings suggest potential adverse health effects in response to CeO 2 nanoparticle exposure. - Highlights: • CeO 2 exposure induced lung fibrosis. • CeO 2 were detected in lung tissue, alveolar type II (ATII) cells and fibroblasts. • CeO 2 caused ATII cell hypertrophy and hyperplasia and altered fibroblast function

Role of epithelial-mesenchymal transition (EMT) and fibroblast function in cerium oxide nanoparticles-induced lung fibrosis

Energy Technology Data Exchange (ETDEWEB)

Ma, Jane [Health Effects Laboratory Division, NIOSH, Morgantown, WV (United States); Bishoff, Bridget [Mylan Pharmaceuticals, Morganntown, WV (United States); Mercer, R.R.; Barger, Mark; Schwegler-Berry, Diane [Health Effects Laboratory Division, NIOSH, Morgantown, WV (United States); Castranova, Vincent, E-mail: vcastran@hsc.wvu.edu [School of Pharmacy, West Virginia University, Morgantown, WV (United States)

2017-05-15

The emission of cerium oxide nanoparticles (CeO{sub 2}) from diesel engines, using cerium compounds as a catalyst to lower the diesel exhaust particles, is a health concern. We have previously shown that CeO{sub 2} induced pulmonary inflammation and lung fibrosis. The objective of the present study was to investigate the modification of fibroblast function and the role of epithelial-mesenchymal transition (EMT) in CeO{sub 2}-induced fibrosis. Male Sprague-Dawley rats were exposed to CeO{sub 2} (0.15 to 7 mg/kg) by a single intratracheal instillation and sacrificed at various times post-exposure. The results show that at 28 days after CeO{sub 2} (3.5 mg/kg) exposure, lung fibrosis was evidenced by increased soluble collagen in bronchoalveolar lavage fluid, elevated hydroxyproline content in lung tissues, and enhanced sirius red staining for collagen in the lung tissue. Lung fibroblasts and alveolar type II (ATII) cells isolated from CeO{sub 2}-exposed rats at 28 days post-exposure demonstrated decreasing proliferation rate when compare to the controls. CeO{sub 2} exposure was cytotoxic and altered cell function as demonstrated by fibroblast apoptosis and aggregation, and ATII cell hypertrophy and hyperplasia with increased surfactant. The presence of stress fibers, expressed as α-smooth muscle actin (SMA), in CeO{sub 2}-exposed fibroblasts and ATII cells was significantly increased compared to the control. Immunohistofluorescence analysis demonstrated co-localization of TGF-β or α-SMA with prosurfactant protein C (SPC)-stained ATII cells. These results demonstrate that CeO{sub 2} exposure affects fibroblast function and induces EMT in ATII cells that play a role in lung fibrosis. These findings suggest potential adverse health effects in response to CeO{sub 2} nanoparticle exposure. - Highlights: • CeO{sub 2} exposure induced lung fibrosis. • CeO{sub 2} were detected in lung tissue, alveolar type II (ATII) cells and fibroblasts. • CeO{sub 2} caused ATII

A novel thermal decomposition approach for the synthesis of silica-iron oxide core–shell nanoparticles

International Nuclear Information System (INIS)

Kishore, P.N.R.; Jeevanandam, P.

2012-01-01

Highlights: ► Silica-iron oxide core–shell nanoparticles have been synthesized by a novel thermal decomposition approach. ► The silica-iron oxide core–shell nanoparticles are superparamagnetic at room temperature. ► The silica-iron oxide core–shell nanoparticles serve as good photocatalyst for the degradation of Rhodamine B. - Abstract: A simple thermal decomposition approach for the synthesis of magnetic nanoparticles consisting of silica as core and iron oxide nanoparticles as shell has been reported. The iron oxide nanoparticles were deposited on the silica spheres (mean diameter = 244 ± 13 nm) by the thermal decomposition of iron (III) acetylacetonate, in diphenyl ether, in the presence of SiO 2 . The core–shell nanoparticles were characterized by X-ray diffraction, infrared spectroscopy, field emission-scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy, diffuse reflectance spectroscopy, and magnetic measurements. The results confirm the presence of iron oxide nanoparticles on the silica core. The core–shell nanoparticles are superparamagnetic at room temperature indicating the presence of iron oxide nanoparticles on silica. The core–shell nanoparticles have been demonstrated as good photocatalyst for the degradation of Rhodamine B.

Interfacial bonding stabilizes rhodium and rhodium oxide nanoparticles on layered Nb oxide and Ta oxide supports.

Science.gov (United States)

Strayer, Megan E; Binz, Jason M; Tanase, Mihaela; Shahri, Seyed Mehdi Kamali; Sharma, Renu; Rioux, Robert M; Mallouk, Thomas E

2014-04-16

Metal nanoparticles are commonly supported on metal oxides, but their utility as catalysts is limited by coarsening at high temperatures. Rhodium oxide and rhodium metal nanoparticles on niobate and tantalate supports are anomalously stable. To understand this, the nanoparticle-support interaction was studied by isothermal titration calorimetry (ITC), environmental transmission electron microscopy (ETEM), and synchrotron X-ray absorption and scattering techniques. Nanosheets derived from the layered oxides KCa2Nb3O10, K4Nb6O17, and RbTaO3 were compared as supports to nanosheets of Na-TSM, a synthetic fluoromica (Na0.66Mg2.68(Si3.98Al0.02)O10.02F1.96), and α-Zr(HPO4)2·H2O. High surface area SiO2 and γ-Al2O3 supports were also used for comparison in the ITC experiments. A Born-Haber cycle analysis of ITC data revealed an exothermic interaction between Rh(OH)3 nanoparticles and the layered niobate and tantalate supports, with ΔH values in the range -32 kJ·mol(-1) Rh to -37 kJ·mol(-1) Rh. In contrast, the interaction enthalpy was positive with SiO2 and γ-Al2O3 supports. The strong interfacial bonding in the former case led to "reverse" ripening of micrometer-size Rh(OH)3, which dispersed as 0.5 to 2 nm particles on the niobate and tantalate supports. In contrast, particles grown on Na-TSM and α-Zr(HPO4)2·H2O nanosheets were larger and had a broad size distribution. ETEM, X-ray absorption spectroscopy, and pair distribution function analyses were used to study the growth of supported nanoparticles under oxidizing and reducing conditions, as well as the transformation from Rh(OH)3 to Rh nanoparticles. Interfacial covalent bonding, possibly strengthened by d-electron acid/base interactions, appear to stabilize Rh(OH)3, Rh2O3, and Rh nanoparticles on niobate and tantalate supports.

Synthesis of oxide-free aluminum nanoparticles for application to conductive film

Science.gov (United States)

Jong Lee, Yung; Lee, Changsoo; Lee, Hyuck Mo

2018-02-01

Aluminum nanoparticles are considered promising as alternatives to conventional ink materials, replacing silver and copper nanoparticles, due to their extremely low cost and low melting temperature. However, a serious obstacle to realizing their use as conductive ink materials is the oxidation of aluminum. In this research, we synthesized the oxide-free aluminum nanoparticles using catalytic decomposition and an oleic acid coating method, and these materials were applied to conductive ink for the first time. The injection time of oleic acid determines the size of the aluminum nanoparticles by forming a self-assembled monolayer on the nanoparticles instead of allowing the formation of an oxide phase. Fabricated nanoparticles were analyzed by transmission electron microscopy and x-ray photoelectron spectroscopy to verify their structural and chemical composition. In addition, conductive inks made of these nanoparticles exhibit electrical properties when they are sintered at over 300 °C in a reducing atmosphere. This result shows that aluminum nanoparticles can be used as an alternative conductive material in printed electronics and can solve the cost issues associated with noble metals.

Microbially-mediated method for synthesis of non-oxide semiconductor nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Phelps, Tommy J.; Lauf, Robert J.; Moon, Ji-Won; Rondinone, Adam Justin; Love, Lonnie J.; Duty, Chad Edward; Madden, Andrew Stephen; Li, Yiliang; Ivanov, Ilia N.; Rawn, Claudia Jeanette

2017-09-19

The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component comprising at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals. The invention is also directed to non-oxide semiconductor nanoparticle compositions produced as above and having distinctive properties.

Microbially-mediated method for synthesis of non-oxide semiconductor nanoparticles

Science.gov (United States)

Phelps, Tommy J.; Lauf, Robert J.; Moon, Ji Won; Rondinone, Adam J.; Love, Lonnie J.; Duty, Chad Edward; Madden, Andrew Stephen; Li, Yiliang; Ivanov, Ilia N.; Rawn, Claudia Jeanette

2014-06-24

The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component containing at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals. The invention is also directed to non-oxide semiconductor nanoparticle compositions produced as above and having distinctive properties.

Dextran-modified iron oxide nanoparticles

Czech Academy of Sciences Publication Activity Database

Hradil, Jiří; Pisarev, A. G.; Babič, Michal; Horák, Daniel

2007-01-01

Roč. 5, 1-2 (2007), s. 162-168 ISSN 1672-2515 R&D Projects: GA ČR GA203/05/2256 Institutional research plan: CEZ:AV0Z40500505 Keywords : iron oxide * nanoparticles * dextran Subject RIV: CD - Macromolecular Chemistry

Electro-oxidation of methanol and formic acid on platinum nanoparticles with different oxidation levels

International Nuclear Information System (INIS)

Hsieh, Chien-Te; Hsiao, Han-Tsung; Tzou, Dong-Ying; Yu, Po-Yuan; Chen, Po-Yen; Jang, Bi-Sheng

2015-01-01

Herein reported is an atomic layer deposition (ALD) process of platinum (Pt) from (methylcyclopentadienyl) trimethylplatinum (MeCpPtMe 3 ) and oxygen (O 2 ) for synthesizing the Pt electrocatalysts toward methanol and formic acid oxidation. The as-synthesized Pt catalysts are thermally reduced in 5 vol% H 2 within temperature window of 150–450 °C. The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species, e.g., PtO and PtO 2 . The presence of Pt–O species not only enhances catalytic activity but also improves anti-poisoning ability toward the oxidation of methanol and formic acid. The improved activity originates from the fact that the Pt–O species, formed by the ALD route, creates a large number of active sites (e.g., Pt–O ads and Pt–(OH) ads ) to strip the CO-adsorbed sites, leading to a high-level of CO tolerance. This work also proposes a stepwise reaction steps to shed some lights on how the Pt–O species promote the catalytic activity. - Highlights: • This study adopts atomic layer deposition (ALD) to grow metallic Pt nanoparticles. • The Pt catalysts show catalytic activity toward methanol and formic acid oxidation. • The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species. • The Pt–O species creates a number of active sites to strip the CO-adsorbed sites. • A stepwise reaction step concerning the promoted catalytic activity is proposed

DNA-length-dependent quenching of fluorescently labeled iron oxide nanoparticles with gold, graphene oxide and MoS2 nanostructures.

Science.gov (United States)

Balcioglu, Mustafa; Rana, Muhit; Robertson, Neil; Yigit, Mehmet V

2014-08-13

We controlled the fluorescence emission of a fluorescently labeled iron oxide nanoparticle using three different nanomaterials with ultraefficient quenching capabilities. The control over the fluorescence emission was investigated via spacing introduced by the surface-functionalized single-stranded DNA molecules. DNA molecules were conjugated on different templates, either on the surface of the fluorescently labeled iron oxide nanoparticles or gold and nanographene oxide. The efficiency of the quenching was determined and compared with various fluorescently labeled iron oxide nanoparticle and nanoquencher combinations using DNA molecules with three different lengths. We have found that the template for DNA conjugation plays significant role on quenching the fluorescence emission of the fluorescently labeled iron oxide nanoparticles. We have observed that the size of the DNA controls the quenching efficiency when conjugated only on the fluorescently labeled iron oxide nanoparticles by setting a spacer between the surfaces and resulting change in the hydrodynamic size. The quenching efficiency with 12mer, 23mer and 36mer oligonucleotides decreased to 56%, 54% and 53% with gold nanoparticles, 58%, 38% and 32% with nanographene oxide, 46%, 38% and 35% with MoS2, respectively. On the other hand, the presence, not the size, of the DNA molecules on the other surfaces quenched the fluorescence significantly with different degrees. To understand the effect of the mobility of the DNA molecules on the nanoparticle surface, DNA molecules were attached to the surface with two different approaches. Covalently immobilized oligonucleotides decreased the quenching efficiency of nanographene oxide and gold nanoparticles to ∼22% and ∼21%, respectively, whereas noncovalently adsorbed oligonucleotides decreased it to ∼25% and ∼55%, respectively. As a result, we have found that each nanoquencher has a powerful quenching capability against a fluorescent nanoparticle, which can be

Size-dependent cytotoxicity of yttrium oxide nanoparticles on primary osteoblasts in vitro

Energy Technology Data Exchange (ETDEWEB)

Zhou, Guoqiang, E-mail: zhougq1982@163.com; Li, Yunfei; Ma, Yanyan; Liu, Zhu; Cao, Lili; Wang, Da; Liu, Sudan; Xu, Wenshi; Wang, Wenying [Hebei University, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science (China)

2016-05-15

Yttrium oxide nanoparticles are an excellent host material for the rare earth metals and have high luminescence efficiency providing a potential application in photodynamic therapy and biological imaging. In this study, the effects of yttrium oxide nanoparticles with four different sizes were investigated using primary osteoblasts in vitro. The results demonstrated that the cytotoxicity generated by yttrium oxide nanoparticles depended on the particle size, and smaller particles possessed higher toxicological effects. For the purpose to elucidate the relationship between reactive oxygen species generation and cell damage, cytomembrane integrity, intracellular reactive oxygen species level, mitochondrial membrane potential, cell apoptosis rate, and activity of caspase-3 in cells were then measured. Increased reactive oxygen species level was also observed in a size-dependent way. Thus, our data demonstrated that exposure to yttrium oxide nanoparticles resulted in a size-dependent cytotoxicity in cultured primary osteoblasts, and reactive oxygen species generation should be one possible damage pathway for the toxicological effects produced by yttrium oxide particles. The results may provide useful information for more rational applications of yttrium oxide nanoparticles in the future.

Toxicity of iron oxide nanoparticles against osteoblasts

International Nuclear Information System (INIS)

Shi Sifeng; Jia Jingfu; Guo Xiaokui; Zhao Yaping; Liu Boyu; Chen Desheng; Guo Yongyuan; Zhang Xianlong

2012-01-01

Magnetic nanoparticles have been widely used for tissue repair, magnetic resonance imaging, immunoassays and drug delivery. They are very promising in orthopaedic applications and several magnetic nanoparticles have been exploited for the treatment of orthopaedic disease. Here, we conducted an in vitro study to examine the interaction of magnetic iron oxide nanoparticles with human osteoblasts to evaluate the dose-related toxicity of the nanoparticles on osteoblasts. A transmission electron microscope was used to visualise the internalised magnetic nanoparticles in osteoblasts. The CCK-8 results revealed increased cell viability (107.5 % vitality compared with the control group) when co-cultured at a low concentration (20 μg/mL) and decreased cell viability (59.5 % vitality in a concentration of 300 μg/mL and 25.9 % in 500 μg/mL) when co-cultured in high concentrations. The flow cytometric detection revealed similar results with 5.48 % of apoptosis in a concentration of 20 μg/mL, 23.40 % of apoptosis in a concentration of 300 μg/mL and 28.49 % in a concentration of 500 μg/mL. The disrupted cytoskeleton of osteoblasts was also revealed using a laser scanning confocal microscope. We concluded that use of a low concentration of magnetic iron oxide nanoparticles is important to avoid damage to osteoblasts.

Toxicity of iron oxide nanoparticles against osteoblasts

Energy Technology Data Exchange (ETDEWEB)

Shi Sifeng [Shanghai Jiao Tong University, Department of Orthopaedic Surgery, Shanghai Sixth People' s Hospital (China); Jia Jingfu [Shanghai Jiao Tong University, School of Chemistry and Chemical Technology (China); Guo Xiaokui [Shanghai Jiao Tong University School of Medicine, Department of Medical Microbiology and Parasitology, Institutes of Medical Sciences (China); Zhao Yaping [Shanghai Jiao Tong University, School of Chemistry and Chemical Technology (China); Liu Boyu [Shanghai Jiao Tong University School of Medicine, Department of Medical Microbiology and Parasitology, Institutes of Medical Sciences (China); Chen Desheng; Guo Yongyuan; Zhang Xianlong, E-mail: zhangxianlong20101@163.com [Shanghai Jiao Tong University, Department of Orthopaedic Surgery, Shanghai Sixth People' s Hospital (China)

2012-09-15

Magnetic nanoparticles have been widely used for tissue repair, magnetic resonance imaging, immunoassays and drug delivery. They are very promising in orthopaedic applications and several magnetic nanoparticles have been exploited for the treatment of orthopaedic disease. Here, we conducted an in vitro study to examine the interaction of magnetic iron oxide nanoparticles with human osteoblasts to evaluate the dose-related toxicity of the nanoparticles on osteoblasts. A transmission electron microscope was used to visualise the internalised magnetic nanoparticles in osteoblasts. The CCK-8 results revealed increased cell viability (107.5 % vitality compared with the control group) when co-cultured at a low concentration (20 {mu}g/mL) and decreased cell viability (59.5 % vitality in a concentration of 300 {mu}g/mL and 25.9 % in 500 {mu}g/mL) when co-cultured in high concentrations. The flow cytometric detection revealed similar results with 5.48 % of apoptosis in a concentration of 20 {mu}g/mL, 23.40 % of apoptosis in a concentration of 300 {mu}g/mL and 28.49 % in a concentration of 500 {mu}g/mL. The disrupted cytoskeleton of osteoblasts was also revealed using a laser scanning confocal microscope. We concluded that use of a low concentration of magnetic iron oxide nanoparticles is important to avoid damage to osteoblasts.

Optical Nonlinear Refractive Index of Laser-Ablated Gold Nanoparticles Graphene Oxide Composite

Directory of Open Access Journals (Sweden)

Amir Reza Sadrolhosseini

2014-01-01

Full Text Available Gold nanoparticles were prepared in graphene oxide using laser ablation technique. The ablation times were varied from 10 to 40 minutes, and the particle size was decreased from 16.55 nm to 5.18 nm in spherical shape. The nanoparticles were capped with carboxyl and the hydroxyl groups were obtained from Fourier transform infrared spectroscopy. Furthermore, the UV-visible peak shifted with decreasing of nanoparticles size, appearing from 528 nm to 510 nm. The Z-scan technique was used to measure the nonlinear refractive indices of graphene oxide with different concentrations and a gold nanoparticle graphene oxide nanocomposite. Consequently, the optical nonlinear refractive indices of graphene oxide and gold nanoparticle graphene oxide nanocomposite were shifted from 1.63×10-9 cm2/W to 4.1×10-9 cm2/W and from 1.85×10-9 cm2/W to 5.8×10-9 cm2/W, respectively.

Contrast agents for MRI based on iron oxide nanoparticles prepared by laser pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Morales, M.P. E-mail: puerto@icmm.csic.es; Bomati-Miguel, O.; Perez de Alejo, R.; Ruiz-Cabello, J.; Veintemillas-Verdaguer, S.; O' Grady, K

2003-10-01

Colloidal suspensions of magnetic particles with application as contrast agents in magnetic resonance imaging have been prepared by coating iron oxide nanoparticles with dextran. The particles were prepared by laser-induced pyrolysis of iron pentacarbonyl vapors. By adjusting the experimental conditions, the particle and crystal size of the iron oxide nanoparticles were varied in the range 2-7 nm with a very narrow size distribution. The suspensions consisted of dextran-coated nanoparticle aggregates with a hydrodynamic diameter of around 50 nm and unimodal size distributions. It was observed that an important enhancement of the magnetic properties of the nanoparticles and the suspensions (saturation magnetization and susceptibility values) takes place as the particle and the crystallite size increases. Consequently, the {sup 1}H NMR relaxation times of the suspensions, characterized by the longitudinal (R{sub 1}) and transversal (R{sub 2}) relaxation rates, also increase with the crystal order. This effect was more pronounced for the values of R{sub 2}. The mechanism of MRI enhancement appears to be related to water protons diffusing within the inhomogeneous magnetic field created by the magnetic clusters. The global structure of the cluster, the anisotropy and the magnetic field around it are important factors affecting the value of R{sub 2}.

Contrast agents for MRI based on iron oxide nanoparticles prepared by laser pyrolysis

International Nuclear Information System (INIS)

Morales, M.P.; Bomati-Miguel, O.; Perez de Alejo, R.; Ruiz-Cabello, J.; Veintemillas-Verdaguer, S.; O'Grady, K.

2003-01-01

Colloidal suspensions of magnetic particles with application as contrast agents in magnetic resonance imaging have been prepared by coating iron oxide nanoparticles with dextran. The particles were prepared by laser-induced pyrolysis of iron pentacarbonyl vapors. By adjusting the experimental conditions, the particle and crystal size of the iron oxide nanoparticles were varied in the range 2-7 nm with a very narrow size distribution. The suspensions consisted of dextran-coated nanoparticle aggregates with a hydrodynamic diameter of around 50 nm and unimodal size distributions. It was observed that an important enhancement of the magnetic properties of the nanoparticles and the suspensions (saturation magnetization and susceptibility values) takes place as the particle and the crystallite size increases. Consequently, the 1 H NMR relaxation times of the suspensions, characterized by the longitudinal (R 1 ) and transversal (R 2 ) relaxation rates, also increase with the crystal order. This effect was more pronounced for the values of R 2 . The mechanism of MRI enhancement appears to be related to water protons diffusing within the inhomogeneous magnetic field created by the magnetic clusters. The global structure of the cluster, the anisotropy and the magnetic field around it are important factors affecting the value of R 2

Determination of Conjugation Efficiency of Antibodies and Proteins to the Superparamagnetic Iron Oxide Nanoparticles by Capillary Electrophoresis with Laser-Induced Fluorescence Detection

Energy Technology Data Exchange (ETDEWEB)

Wang, F.-H.; Yoshitake, Takashi [Karolinska Institutet, Department of Neuroscience (Sweden); Kim, Do-Kyung; Muhammed, Mamoun [Royal Institute of Technology, Materials Chemistry Division (Sweden); Bjelke, Boerje [MRI-Center, Experimental Unit, Karolinska Institutet (Sweden); Kehr, Jan [Karolinska Institutet, Department of Neuroscience (Sweden)], E-mail: Jan.Kehr@neuro.ki.se

2003-04-15

The method based on capillary electrophoresis with laser-induced fluorescence detection (CE/LIF) was developed for determination of magnetic iron oxide nanoparticles (hydrodynamic diameters of 100 nm) functionalized with molecules containing primary amino groups. The magnetic nanoparticles with carboxylic or aminopropyl-trimethoxysilane groups at their surface were conjugated to the model proteins (bovine serum albumin, BSA; streptavidin or goat anti-rabbit immunoglobulin G, IgG) using carbodiimide as a zero-length cross-linker.The nanoparticle-protein conjugates (hydrodynamic diameter 163-194 nm) were derivatized with naphthalene-2,3-dicarboxaldehyde reagent and separated by CE/LIF with a helium-cadmium laser (excitation at 442 nm, emission at 488 nm). The separations were carried out by using a fused-silica capillary (effective length 48 cm, inner diameter 75 um) and 100 mM sodium borate buffer (pH 9.2), the potential was 30 kV. The detection limit for BSA-conjugate was 1.3 pg/10 nl, i.e. about 20 amol. The present method provides an efficient and fast tool for sensitive determination of the efficacy of biomolecular functionalization of magnetic nanoparticles. The CE/LIF technique requires only negligible sample volumes for analysis, which is especially suitable for controlling the process of preparation of functionalized nanoparticles with unique properties aimed to be used for diagnostic or therapeutic purposes.

Pulmonary toxicity of well-dispersed cerium oxide nanoparticles following intratracheal instillation and inhalation

Energy Technology Data Exchange (ETDEWEB)

Morimoto, Yasuo, E-mail: yasuom@med.uoeh-u.ac.jp; Izumi, Hiroto; Yoshiura, Yukiko; Tomonaga, Taisuke; Oyabu, Takako; Myojo, Toshihiko; Kawai, Kazuaki; Yatera, Kazuhiro [University of Occupational and Environmental Health (Japan); Shimada, Manabu; Kubo, Masaru [Hiroshima University (Japan); Yamamoto, Kazuhiro [National Institute of Advanced Industrial Science and Technology (AIST) (Japan); Kitajima, Shinichi [National Sanatorium Hoshizuka Keiaien (Japan); Kuroda, Etsushi [Osaka University, Laboratory of Vaccine Science, WPI Immunology Frontier Research Center (Japan); Kawaguchi, Kenji; Sasaki, Takeshi [National Institute of Advanced Industrial Science and Technology (AIST) (Japan)

2015-11-15

We performed inhalation and intratracheal instillation studies of cerium dioxide (CeO{sub 2}) nanoparticles in order to investigate their pulmonary toxicity, and observed pulmonary inflammation not only in the acute and but also in the chronic phases. In the intratracheal instillation study, F344 rats were exposed to 0.2 mg or 1 mg of CeO{sub 2} nanoparticles. Cell analysis and chemokines in bronchoalveolar lavage fluid (BALF) were analyzed from 3 days to 6 months following the instillation. In the inhalation study, rats were exposed to the maximum concentration of inhaled CeO{sub 2} nanoparticles (2, 10 mg/m{sup 3}, respectively) for 4 weeks (6 h/day, 5 days/week). The same endpoints as in the intratracheal instillation study were examined from 3 days to 3 months after the end of the exposure. The intratracheal instillation of CeO{sub 2} nanoparticles caused a persistent increase in the total and neutrophil number in BALF and in the concentration of cytokine-induced neutrophil chemoattractant (CINC)-1, CINC-2, chemokine for neutrophil, and heme oxygenase-1 (HO-1), an oxidative stress marker, in BALF during the observation time. The inhalation of CeO{sub 2} nanoparticles also induced a persistent influx of neutrophils and expression of CINC-1, CINC-2, and HO-1 in BALF. Pathological features revealed that inflammatory cells, including macrophages and neutrophils, invaded the alveolar space in both studies. Taken together, the CeO{sub 2} nanoparticles induced not only acute but also chronic inflammation in the lung, suggesting that CeO{sub 2} nanoparticles have a pulmonary toxicity that can lead to irreversible lesions.

Polymer-supported metals and metal oxide nanoparticles: synthesis, characterization, and applications

International Nuclear Information System (INIS)

Sarkar, Sudipta; Guibal, E.; Quignard, F.; SenGupta, A. K.

2012-01-01

Metal and metal oxide nanoparticles exhibit unique properties in regard to sorption behaviors, magnetic activity, chemical reduction, ligand sequestration among others. To this end, attempts are being continuously made to take advantage of them in multitude of applications including separation, catalysis, environmental remediation, sensing, biomedical applications and others. However, metal and metal oxide nanoparticles lack chemical stability and mechanical strength. They exhibit extremely high pressure drop or head loss in fixed-bed column operation and are not suitable for any flow-through systems. Also, nanoparticles tend to aggregate; this phenomenon reduces their high surface area to volume ratio and subsequently reduces effectiveness. By appropriately dispersing metal and metal oxide nanoparticles into synthetic and naturally occurring polymers, many of the shortcomings can be overcome without compromising the parent properties of the nanoparticles. Furthermore, the appropriate choice of the polymer host with specific functional groups may even lead to the enhancement of the properties of nanoparticles. The synthesis of hybrid materials involves two broad pathways: dispersing the nanoparticles (i) within pre-formed or commercially available polymers; and (ii) during the polymerization process. This review presents a broad coverage of nanoparticles and polymeric/biopolymeric host materials and the resulting properties of the hybrid composites. In addition, the review discusses the role of the Donnan membrane effect exerted by the host functionalized polymer in harnessing the desirable properties of metal and metal oxide nanoparticles for intended applications.

Functionalized iron oxide nanoparticles for controlling the movement of immune cells

Science.gov (United States)

White, Ethan E.; Pai, Alex; Weng, Yiming; Suresh, Anil K.; van Haute, Desiree; Pailevanian, Torkom; Alizadeh, Darya; Hajimiri, Ali; Badie, Behnam; Berlin, Jacob M.

2015-04-01

Immunotherapy is currently being investigated for the treatment of many diseases, including cancer. The ability to control the location of immune cells during or following activation would represent a powerful new technique for this field. Targeted magnetic delivery is emerging as a technique for controlling cell movement and localization. Here we show that this technique can be extended to microglia, the primary phagocytic immune cells in the central nervous system. The magnetized microglia were generated by loading the cells with iron oxide nanoparticles functionalized with CpG oligonucleotides, serving as a proof of principle that nanoparticles can be used to both deliver an immunostimulatory cargo to cells and to control the movement of the cells. The nanoparticle-oligonucleotide conjugates are efficiently internalized, non-toxic, and immunostimulatory. We demonstrate that the in vitro migration of the adherent, loaded microglia can be controlled by an external magnetic field and that magnetically-induced migration is non-cytotoxic. In order to capture video of this magnetically-induced migration of loaded cells, a novel 3D-printed ``cell box'' was designed to facilitate our imaging application. Analysis of cell movement velocities clearly demonstrate increased cell velocities toward the magnet. These studies represent the initial step towards our final goal of using nanoparticles to both activate immune cells and to control their trafficking within the diseased brain.Immunotherapy is currently being investigated for the treatment of many diseases, including cancer. The ability to control the location of immune cells during or following activation would represent a powerful new technique for this field. Targeted magnetic delivery is emerging as a technique for controlling cell movement and localization. Here we show that this technique can be extended to microglia, the primary phagocytic immune cells in the central nervous system. The magnetized microglia were

Enzymatic oxidative biodegradation of nanoparticles: Mechanisms, significance and applications

Energy Technology Data Exchange (ETDEWEB)

Vlasova, Irina I. [Department of Environmental and Occupational Health, Center for Free Radical and Antioxidant Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15219 (United States); Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow 119453 (Russian Federation); Kapralov, Alexandr A. [Department of Environmental and Occupational Health, Center for Free Radical and Antioxidant Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15219 (United States); Michael, Zachary P.; Burkert, Seth C. [Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Shurin, Michael R. [Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA 15261 (United States); Department of Immunology, University of Pittsburgh Medical Center, Pittsburgh, PA 15261 (United States); Star, Alexander [Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Shvedova, Anna A., E-mail: ats@cdc.gov [Pathology and Physiology Research Branch, Health Effects Laboratory Division (HELD), National Institute for Occupational Safety and Health (NIOSH) and Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26505 (United States); Kagan, Valerian E., E-mail: kagan@pitt.edu [Department of Environmental and Occupational Health, Center for Free Radical and Antioxidant Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15219 (United States); Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Departments of Pharmacology and Chemical Biology and Radiation Oncology, University of Pittsburgh, Pittsburgh, PA 15260 (United States)

2016-05-15

Biopersistence of carbon nanotubes, graphene oxide (GO) and several other types of carbonaceous nanomaterials is an essential determinant of their health effects. Successful biodegradation is one of the major factors defining the life span and biological responses to nanoparticles. Here, we review the role and contribution of different oxidative enzymes of inflammatory cells – myeloperoxidase, eosinophil peroxidase, lactoperoxidase, hemoglobin, and xanthine oxidase – to the reactions of nanoparticle biodegradation. We further focus on interactions of nanomaterials with hemoproteins dependent on the specific features of their physico-chemical and structural characteristics. Mechanistically, we highlight the significance of immobilized peroxidase reactive intermediates vs diffusible small molecule oxidants (hypochlorous and hypobromous acids) for the overall oxidative biodegradation process in neutrophils and eosinophils. We also accentuate the importance of peroxynitrite-driven pathways realized in macrophages via the engagement of NADPH oxidase- and NO synthase-triggered oxidative mechanisms. We consider possible involvement of oxidative machinery of other professional phagocytes such as microglial cells, myeloid-derived suppressor cells, in the context of biodegradation relevant to targeted drug delivery. We evaluate the importance of genetic factors and their manipulations for the enzymatic biodegradation in vivo. Finally, we emphasize a novel type of biodegradation realized via the activation of the “dormant” peroxidase activity of hemoproteins by the nano-surface. This is exemplified by the binding of GO to cyt c causing the unfolding and ‘unmasking’ of the peroxidase activity of the latter. We conclude with the strategies leading to safe by design carbonaceous nanoparticles with optimized characteristics for mechanism-based targeted delivery and regulatable life-span of drugs in circulation. - Highlights: • Nanoparticles can be degraded by

Orthogonal Clickable Iron Oxide Nanoparticle Platform for Targeting, Imaging, and On-Demand Release.

Science.gov (United States)

Guldris, Noelia; Gallo, Juan; García-Hevia, Lorena; Rivas, José; Bañobre-López, Manuel; Salonen, Laura M

2018-04-12

A versatile iron oxide nanoparticle platform is reported that can be orthogonally functionalized to obtain highly derivatized nanomaterials required for a wide variety of applications, such as drug delivery, targeted therapy, or imaging. Facile functionalization of the nanoparticles with two ligands containing isocyanate moieties allows for high coverage of the surface with maleimide and alkyne groups. As a proof-of-principle, the nanoparticles were subsequently functionalized with a fluorophore as a drug model and with biotin as a targeting ligand towards tumor cells through Diels-Alder and azide-alkyne cycloaddition reactions, respectively. The thermoreversibility of the Diels-Alder product was exploited to induce the on-demand release of the loaded molecules by magnetic hyperthermia. Additionally, the nanoparticles were shown to target cancer cells through in vitro experiments, as analyzed by magnetic resonance imaging. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of iron oxide nanoparticles via sonochemical method and their characterization

Institute of Scientific and Technical Information of China (English)

Amir Hassanjani-Roshan; Mohammad Reza Vaezi; Ali Shokuhfar; Zohreh Rajabali

2011-01-01

Preparation of iron oxide (α-Fe2O3) nanoparticles was carried out via a sonochemical process. The process parameters such as temperature,sonication time and power of ultrasonication play important roles in the size and morphology of the final products. The iron oxide nanoparticles were characterized by transmission electron microscopy,X-ray powder diffraction,and thermogravimetric and differential thermal analyses. From transmission electron microscopy observations,the size of the iron oxide nanoparticles is estimated to be significantly smaller than 19 nm. X-ray diffraction data of the powder after annealing provide direct evidence that the iron oxide was formed during the sonochemical process.

Chronic exposure of zinc oxide nanoparticles causes deviant phenotype in Drosophila melanogaster

Energy Technology Data Exchange (ETDEWEB)

Anand, Avnika Singh; Prasad, Dipti N.; Singh, Shashi Bala; Kohli, Ekta, E-mail: ektakohli@hotmail.com

2017-04-05

Zinc oxide nanoparticles (ZnO NPs) are commonly used nanomaterials (NMs) with versatile applications from high-end technologies to household products. This pervasive utilisation has brought human in the close interface with nanoparticles (NPs), hence questioning their safety prior to usage is a must. In this study, we have assessed the effects of chronic exposure to ZnO NPs (<50 nm) on the model organism Drosophila melanogaster. Potential toxic effects were studied by evaluating longevity, climbing ability, oxidative stress and DNA fragmentation. Ensuing exposure, the F0 (parent), F1, F2, F3 and F4 generation flies were screened for the aberrant phenotype. Flies exposed to ZnO NPs showed distinctive phenotypic changes, like deformed segmented thorax and single or deformed wing, which were transmitted to the offspring’s in subsequent generations. The unique abnormal phenotype is evident of chronic toxicity induced by ZnO NPs, although appalling, it strongly emphasize the importance to understand NPs toxicity for safer use.

Gold nanoparticle catalyzed oxidation of alcohols - From biomass to commodity chemicals

DEFF Research Database (Denmark)

Taarning, Esben; Christensen, Claus H.

2007-01-01

and glycerol are rich in alcohol functionalities. Thus, a key step in utilizing these resources lies in the conversion of this functional group. Benign oxidations involving oxygen as the stoichiometric oxidant are important from both an environmental and economical perspective. Recently, it has become clear...... that supported gold nanoparticles are highly active catalysts for oxidizing alcohols and aldehydes using oxygen as the oxidant. This perspective will focus on the use of gold nanoparticles in the oxidation of renewables....

Mercury removal in wastewater by iron oxide nanoparticles

International Nuclear Information System (INIS)

Vélez, E; Campillo, G E; Morales, G; Hincapié, C; Osorio, J; Arnache, O; Uribe, J I; Jaramillo, F

2016-01-01

Mercury is one of the persistent pollutants in wastewater; it is becoming a severe environmental and public health problem, this is why nowadays its removal is an obligation. Iron oxide nanoparticles are receiving much attention due to their properties, such as: great biocompatibility, ease of separation, high relation of surface-area to volume, surface modifiability, reusability, excellent magnetic properties and relative low cost. In this experiment, Fe 3 O 4 and γ-Fe 2 O 3 nanoparticles were synthesized using iron salts and NaOH as precipitation agents, and Aloe Vera as stabilizing agent; then these nanoparticles were characterized by three different measurements: first, using a Zetasizer Nano ZS for their size estimation, secondly UV-visible spectroscopy which showed the existence of resonance of plasmon at λ max ∼360 nm, and lastly by Scanning Electron Microscopy (SEM) to determine nanoparticles form. The results of this characterization showed that the obtained Iron oxides nanoparticles have a narrow size distribution (∼100nm). Mercury removal of 70% approximately was confirmed by atomic absorption spectroscopy measurements. (paper)

A halogen-free synthesis of gold nanoparticles using gold(III) oxide

International Nuclear Information System (INIS)

Sashuk, Volodymyr; Rogaczewski, Konrad

2016-01-01

Gold nanoparticles are one of the most used nanomaterials. They are usually synthesized by the reduction of gold(III) chloride. However, the presence of halide ions in the reaction mixture is not always welcome. In some cases, these ions have detrimental influence on the morphology and structure of resulting nanoparticles. Here, we present a simple and halogen-free procedure to prepare gold nanoparticles by reduction of gold(III) oxide in neat oleylamine. The method provides the particles with an average size below 10 nm and dispersity of tens of percent. The process of nanoparticle formation was monitored using UV–Vis spectroscopy. The structure and chemical composition of the nanoparticles was determined by SEM, XPS and EDX. We also proposed the mechanism of reduction of gold(III) oxide based on MS, IR and NMR data. Importantly, the synthetic protocol is general and applicable for the preparation of other coinage metal nanoparticles from the corresponding metal oxides. For instance, we demonstrated that the absence of halogen enables efficient alloying of metals when preparing gold–silver bimetallic nanoparticles.

Investigation of carrier oil stabilized iron oxide nanoparticles and its ...

African Journals Online (AJOL)

Iron oxide nanoparticles were synthesized by co-precipitation method. The polyunsaturated carrier oil (flaxseed oil) is used as a stabilizing agent for iron oxide nanoparticles. Kirby Bauer method was used to investigate the antibiotic sensitivity of carrier oil stabilized and uncoated SPIONs at 10 and 20 μg/L on Gram-positive ...

Preparation and Biocompatible Surface Modification of Redox Altered Cerium Oxide Nanoparticle Promising for Nanobiology and Medicine

KAUST Repository

Nanda, Himansu Sekhar

2016-11-03

The biocompatible surface modification of metal oxide nanoparticles via surface functionalization technique has been used as an important tool in nanotechnology and medicine. In this report, we have prepared aqueous dispersible, trivalent metal ion (samarium)-doped cerium oxide nanoparticles (SmCNPs) as model redox altered CNPs of biological relevance. SmCNP surface modified with hydrophilic biocompatible (6-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-hexyl) triethoxysilane (MEEETES) were prepared using ammonia-induced ethylene glycol-assisted precipitation method and were characterized using a variety of complementary characterization techniques. The chemical interaction of functional moieties with the surface of doped nanoparticle was studied using powerful 13C cross polarization magic angle sample spinning nuclear magnetic resonance spectroscopy. The results demonstrated the production of the extremely small size MEEETES surface modified doped nanoparticles with significant reduction in aggregation compared to their unmodified state. Moreover, the functional moieties had strong chemical interaction with the surface of the doped nanoparticles. The biocompatible surface modification using MEEETES should also be extended to several other transition metal ion doped and co-doped CNPs for the production of aqueous dispersible redox altered CNPs that are promising for nanobiology and medicine.

Preparation and Biocompatible Surface Modification of Redox Altered Cerium Oxide Nanoparticle Promising for Nanobiology and Medicine

KAUST Repository

Nanda, Himansu Sekhar

2016-01-01

The biocompatible surface modification of metal oxide nanoparticles via surface functionalization technique has been used as an important tool in nanotechnology and medicine. In this report, we have prepared aqueous dispersible, trivalent metal ion (samarium)-doped cerium oxide nanoparticles (SmCNPs) as model redox altered CNPs of biological relevance. SmCNP surface modified with hydrophilic biocompatible (6-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-hexyl) triethoxysilane (MEEETES) were prepared using ammonia-induced ethylene glycol-assisted precipitation method and were characterized using a variety of complementary characterization techniques. The chemical interaction of functional moieties with the surface of doped nanoparticle was studied using powerful 13C cross polarization magic angle sample spinning nuclear magnetic resonance spectroscopy. The results demonstrated the production of the extremely small size MEEETES surface modified doped nanoparticles with significant reduction in aggregation compared to their unmodified state. Moreover, the functional moieties had strong chemical interaction with the surface of the doped nanoparticles. The biocompatible surface modification using MEEETES should also be extended to several other transition metal ion doped and co-doped CNPs for the production of aqueous dispersible redox altered CNPs that are promising for nanobiology and medicine.

Preparation and Biocompatible Surface Modification of Redox Altered Cerium Oxide Nanoparticle Promising for Nanobiology and Medicine

Directory of Open Access Journals (Sweden)

Himansu Sekhar Nanda

2016-11-01

Full Text Available The biocompatible surface modification of metal oxide nanoparticles via surface functionalization technique has been used as an important tool in nanotechnology and medicine. In this report, we have prepared aqueous dispersible, trivalent metal ion (samarium-doped cerium oxide nanoparticles (SmCNPs as model redox altered CNPs of biological relevance. SmCNP surface modified with hydrophilic biocompatible (6-{2-[2-(2-methoxy-ethoxy-ethoxy]-ethoxy}-hexyl triethoxysilane (MEEETES were prepared using ammonia-induced ethylene glycol-assisted precipitation method and were characterized using a variety of complementary characterization techniques. The chemical interaction of functional moieties with the surface of doped nanoparticle was studied using powerful 13C cross polarization magic angle sample spinning nuclear magnetic resonance spectroscopy. The results demonstrated the production of the extremely small size MEEETES surface modified doped nanoparticles with significant reduction in aggregation compared to their unmodified state. Moreover, the functional moieties had strong chemical interaction with the surface of the doped nanoparticles. The biocompatible surface modification using MEEETES should also be extended to several other transition metal ion doped and co-doped CNPs for the production of aqueous dispersible redox altered CNPs that are promising for nanobiology and medicine.

Effect of Magnesium Oxide Nanoparticles on Water Glass Structure

Directory of Open Access Journals (Sweden)

Bobrowski A.

2012-09-01

Full Text Available An attempt has been made to determine the effect of an addition of colloidal suspensions of the nanoparticles of magnesium oxide on the structure of water glass, which is a binder for moulding and core sands. Nanoparticles of magnesium oxide MgO in propanol and ethanol were introduced in the same mass content (5wt.% and structural changes were determined by measurement of the FT-IR absorption spectra.

Synthesis of tungsten oxide, silver, and gold nanoparticles by radio frequency plasma in water

International Nuclear Information System (INIS)

Hattori, Yoshiaki; Nomura, Shinfuku; Mukasa, Shinobu; Toyota, Hiromichi; Inoue, Toru; Usui, Tomoya

2013-01-01

Highlights: •RF plasma in water was used for nanoparticle synthesis. •Nanoparticles were produced from erosion of metallic electrode. •Rectangular and spherical tungsten oxide nanoparticles were produced. •No oxidations of the silver and gold spherical nanoparticles were produced. -- Abstract: A process for synthesis of nanoparticles using plasma in water generated by a radio frequency of 27.12 MHz is proposed. Tungsten oxide, silver, and gold nanoparticles were produced at 20 kPa through erosion of a metallic electrode exposed to plasma. Characterization of the produced nanoparticles was carried out by XRD, absorption spectrum, and TEM. The nanoparticle sizes were compared with those produced by a similar technique using plasma in liquid

Room-temperature solution synthesis of Ag nanoparticle functionalized molybdenum oxide nanowires and their catalytic applications.

Science.gov (United States)

Dong, Wenjun; Huang, Huandi; Zhu, Yanjun; Li, Xiaoyun; Wang, Xuebin; Li, Chaorong; Chen, Benyong; Wang, Ge; Shi, Zhan

2012-10-26

A simple chemical solution route for the synthesis of large-scale high-quality Ag nanoparticle functionalized molybdenum oxide nanowire at room temperature has been developed. In the synthesis, the protonated amine was intercalated into the molybdenum bronze layers to reduce the electrostatic force of the lamellar structures, and then the Ag nanoparticle functionalized long nanowires could be easily induced by a redox reaction between a molybdenum oxide-amine intermediate and Ag(+) at room temperature. The intercalation lamellar structures improved the nucleation and growth of the Ag nanoparticles, with the result that uniform Ag nanoparticles occurred on the surface of the MoO(3) nanowire. In this way Ag nanoparticles with average sizes of around 6 nm, and high-purity nanowires with mean diameter of around 50 nm and with typical lengths of several tens to hundreds of micrometers were produced. The heteronanostructured nanowires were intricately and inseparably connected to each other with hydrogen bonds and/or bridge oxygen atoms and packed together, forming a paper-like porous network film. The Ag-MoO(3) nanowire film performs a promoted catalytic property for the epoxidation of cis-cyclooctene, and the heteronanostructured nanowire film sensor shows excellent sensing performance to hydrogen and oxygen at room temperature.

Zinc oxide nanoparticles and monocytes: Impact of size, charge and solubility on activation status

International Nuclear Information System (INIS)

Prach, Morag; Stone, Vicki; Proudfoot, Lorna

2013-01-01

Zinc oxide (ZnO) particle induced cytotoxicity was dependent on size, charge and solubility, factors which at sublethal concentrations may influence the activation of the human monocytic cell line THP1. ZnO nanoparticles (NP; average diameter 70 nm) were more toxic than the bulk form ( 2+ ion with protein. This association with protein may influence interaction of the ZnO particles and NP with THP1 cells. After 24 h exposure to the ZnO particles and NP at sublethal concentrations there was little effect on immunological markers of inflammation such as HLA DR and CD14, although they may induce a modest increase in the adhesion molecule CD11b. The cytokine TNFα is normally associated with proinflammatory immune responses but was not induced by the ZnO particles and NP. There was also no effect on LPS stimulated TNFα production. These results suggest that ZnO particles and NP do not have a classical proinflammatory effect on THP1 cells. -- Highlights: ► ZnO is cytotoxic to THP-1 monocytes. ► ZnO nanoparticles are more toxic than the bulk form. ► Positive charge enhances ZnO nanoparticle cytotoxicity. ► Sublethal doses of ZnO particles do not induce classical proinflammatory markers.

Morphology-dependent activity of Pt nanocatalysts for ethanol oxidation in acidic media: Nanowires versus nanoparticles

International Nuclear Information System (INIS)

Zhou Weiping; Li Meng; Koenigsmann, Christopher; Ma Chao; Wong, Stanislaus S.; Adzic, Radoslav R.

2011-01-01

Highlights: → We demonstrate the morphology effect of Pt catalysts in electrooxidation of ethanol and CO in an acidic solution. → Pt nanowires and nanoparticles were used as catalysts. → Pt nanowires display a higher catalytic activity by a factor of at least two relative to those nanoparticles for ethanol oxidation. → The rate for CO monolayer oxidation exhibits similar morphology-dependent behavior with a markedly enhanced rate on the Pt nanowires. - Abstract: The morphology of nanostructured Pt catalysts is known to affect significantly the kinetics of various reactions. Herein, we report on a pronounced morphology effect in the electrooxidation of ethanol and carbon monoxide (CO) on Pt nanowires and nanoparticles in an acidic solution. The high resolution transmission electron microscopy analysis showed the inherent morphology difference between these two nanostructured catalysts. Voltammetric and chronoamperometric studies of the ethanol electrooxidation revealed that these nanowires had a higher catalytic activity by a factor of two relative to these nanoparticles. The rate for CO monolayer oxidation exhibits similar morphology-dependent behavior with a markedly enhanced rate on the Pt nanowires. In situ infrared reflection-absorption spectroscopy measurements revealed a different trend for chemisorbed CO formation and CO 2 -to-acetic acid reaction product ratios on these two nanostructures. The morphology-induced change in catalytic activity and selectivity in ethanol electrocatalysis is discussed in detail.

Morphology-dependent activity of Pt nanocatalysts for ethanol oxidation in acidic media: Nanowires versus nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Zhou Weiping, E-mail: wpzhou@bnl.gov [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Li Meng [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Koenigsmann, Christopher [Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794 (United States); Ma Chao [Condensed Matter Physics and Materials Sciences Department, Brookhaven National Laboratory, Building 480, Upton, NY 11973 (United States); Wong, Stanislaus S. [Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794 (United States); Condensed Matter Physics and Materials Sciences Department, Brookhaven National Laboratory, Building 480, Upton, NY 11973 (United States); Adzic, Radoslav R. [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

2011-11-30

Highlights: > We demonstrate the morphology effect of Pt catalysts in electrooxidation of ethanol and CO in an acidic solution. > Pt nanowires and nanoparticles were used as catalysts. > Pt nanowires display a higher catalytic activity by a factor of at least two relative to those nanoparticles for ethanol oxidation. > The rate for CO monolayer oxidation exhibits similar morphology-dependent behavior with a markedly enhanced rate on the Pt nanowires. - Abstract: The morphology of nanostructured Pt catalysts is known to affect significantly the kinetics of various reactions. Herein, we report on a pronounced morphology effect in the electrooxidation of ethanol and carbon monoxide (CO) on Pt nanowires and nanoparticles in an acidic solution. The high resolution transmission electron microscopy analysis showed the inherent morphology difference between these two nanostructured catalysts. Voltammetric and chronoamperometric studies of the ethanol electrooxidation revealed that these nanowires had a higher catalytic activity by a factor of two relative to these nanoparticles. The rate for CO monolayer oxidation exhibits similar morphology-dependent behavior with a markedly enhanced rate on the Pt nanowires. In situ infrared reflection-absorption spectroscopy measurements revealed a different trend for chemisorbed CO formation and CO{sub 2}-to-acetic acid reaction product ratios on these two nanostructures. The morphology-induced change in catalytic activity and selectivity in ethanol electrocatalysis is discussed in detail.

Morphological changes of the red blood cells treated with metal oxide nanoparticles.

Science.gov (United States)

Kozelskaya, A I; Panin, A V; Khlusov, I A; Mokrushnikov, P V; Zaitsev, B N; Kuzmenko, D I; Vasyukov, G Yu

2016-12-01

The toxic effect of Al 2 O 3 , SiО 2 and ZrО 2 nanoparticles on red blood cells of Wistar rats was studied in vitro using the atomic force microscopy and the fluorescence analysis. Transformation of discocytes into echinocytes and spherocytes caused by the metal oxide nanoparticles was revealed. It was shown that only extremely high concentration of the nanoparticles (2mg/ml) allows correct estimating of their effect on the cell morphology. Besides, it was found out that the microviscosity changes of red blood cell membranes treated with nanoparticles began long before morphological modifications of the cells. On the contrary, the negatively charged ZrO 2 and SiO 2 nanoparticles did not affect ghost microviscosity up to concentrations of 1μg/ml and 0.1mg/ml, correspondingly. In its turn, the positively charged Al 2 O 3 nanoparticles induced structural changes in the lipid bilayer of the red blood cells already at a concentration of 0.05μg/ml. A decrease in microviscosity of the erythrocyte ghosts treated with Al 2 O 3 and SiO 2 nanoparticles was shown. It was detected that the interaction of ZrO 2 nanoparticles with the cells led to an increase in the membrane microviscosity and cracking of swollen erythrocytes. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of gadolinium oxide nanoparticles on the oxidative burst from human neutrophil granulocytes

International Nuclear Information System (INIS)

Abrikossova, Natalia; Skoglund, Caroline; Ahrén, Maria; Uvdal, Kajsa; Bengtsson, Torbjörn

2012-01-01

We have previously shown that gadolinium oxide (Gd 2 O 3 ) nanoparticles are promising candidates to be used as contrast agents in magnetic resonance (MR) imaging applications. In this study, these nanoparticles were investigated in a cellular system, as possible probes for visualization and targeting intended for bioimaging applications. We evaluated the impact of the presence of Gd 2 O 3 nanoparticles on the production of reactive oxygen species (ROS) from human neutrophils, by means of luminol-dependent chemiluminescence. Three sets of Gd 2 O 3 nanoparticles were studied, i.e. as synthesized, dialyzed and both PEG-functionalized and dialyzed Gd 2 O 3 nanoparticles. In addition, neutrophil morphology was evaluated by fluorescent staining of the actin cytoskeleton and fluorescence microscopy. We show that surface modification of these nanoparticles with polyethylene glycol (PEG) is essential in order to increase their biocompatibility. We observed that the as synthesized nanoparticles markedly decreased the ROS production from neutrophils challenged with prey (opsonized yeast particles) compared to controls without nanoparticles. After functionalization and dialysis, more moderate inhibitory effects were observed at a corresponding concentration of gadolinium. At lower gadolinium concentration the response was similar to that of the control cells. We suggest that the diethylene glycol (DEG) present in the as synthesized nanoparticle preparation is responsible for the inhibitory effects on the neutrophil oxidative burst. Indeed, in the present study we also show that even a low concentration of DEG, 0.3%, severely inhibits neutrophil function. In summary, the low cellular response upon PEG-functionalized Gd 2 O 3 nanoparticle exposure indicates that these nanoparticles are promising candidates for MR-imaging purposes. (paper)

Solid-stabilized emulsion formation using stearoyl lactylate coated iron oxide nanoparticles

Science.gov (United States)

Vengsarkar, Pranav S.; Roberts, Christopher B.

2014-10-01

Iron oxide nanoparticles can exhibit highly tunable physicochemical properties that are extremely important in applications such as catalysis, biomedicine and environmental remediation. The small size of iron oxide nanoparticles can be used to stabilize oil-in-water Pickering emulsions due to their high energy of adsorption at the interface of oil droplets in water. The objective of this work is to investigate the effect of the primary particle characteristics and stabilizing agent chemistry on the stability of oil-in-water Pickering emulsions. Iron oxide nanoparticles were synthesized by the co-precipitation method using stoichiometric amounts of Fe2+ and Fe3+ salts. Sodium stearoyl lactylate (SSL), a Food and Drug Administration approved food additive, was used to functionalize the iron oxide nanoparticles. SSL is useful in the generation of fat-in-water emulsions due to its high hydrophilic-lipophilic balance and its bilayer-forming capacity. Generation of a monolayer or a bilayer coating on the nanoparticles was controlled through systematic changes in reagent concentrations. The coated particles were then characterized using various analytical techniques to determine their size, their crystal structure and surface functionalization. The capacity of these bilayer coated nanoparticles to stabilize oil-in-water emulsions under various salt concentrations and pH values was also systematically determined using various characterization techniques. This study successfully demonstrated the ability to synthesize iron oxide nanoparticles (20-40 nm) coated with SSL in order to generate stable Pickering emulsions that were pH-responsive and resistant to significant destabilization in a saline environment, thereby lending themselves to applications in advanced oil spill recovery and remediation.

Facile solid-state synthesis of oxidation-resistant metal nanoparticles at ambient conditions

Science.gov (United States)

Lee, Kyu Hyung; Jung, Hyuk Joon; Lee, Ju Hee; Kim, Kyungtae; Lee, Byeongno; Nam, Dohyun; Kim, Chung Man; Jung, Myung-Hwa; Hur, Nam Hwi

2018-05-01

A simple and scalable method for the synthesis of metal nanoparticles in the solid-state was developed, which can produce nanoparticles in the absence of solvents. Nanoparticles of coinage metals were synthesized by grinding solid hydrazine and the metal precursors in their acetates and oxides at 25 °C. The silver and gold acetates converted completely within 6 min into Ag and Au nanoparticles, respectively, while complete conversion of the copper acetate to the Cu sub-micrometer particles took about 2 h. Metal oxide precursors were also converted into metal nanoparticles by grinding alone. The resulting particles exhibit distinctive crystalline lattice fringes, indicating the formation of highly crystalline phases. The Cu sub-micrometer particles are better resistant to oxidation and exhibit higher conductivity compared to conventional Cu nanoparticles. This solid-state method was also applied for the synthesis of platinum group metals and intermetallic Cu3Au, which can be further extended to synthesize other metal nanoparticles.

Scalable fractionation of iron oxide nanoparticles using a CO2 gas-expanded liquid system

International Nuclear Information System (INIS)

Vengsarkar, Pranav S.; Xu, Rui; Roberts, Christopher B.

2015-01-01

Iron oxide nanoparticles exhibit highly size-dependent physicochemical properties that are important in applications such as catalysis and environmental remediation. In order for these size-dependent properties to be effectively harnessed for industrial applications scalable and cost-effective techniques for size-controlled synthesis or size separation must be developed. The synthesis of monodisperse iron oxide nanoparticles can be a prohibitively expensive process on a large scale. An alternative involves the use of inexpensive synthesis procedures followed by a size-selective processing technique. While there are many techniques available to fractionate nanoparticles, many of the techniques are unable to efficiently fractionate iron oxide nanoparticles in a scalable and inexpensive manner. A scalable apparatus capable of fractionating large quantities of iron oxide nanoparticles into distinct fractions of different sizes and size distributions has been developed. Polydisperse iron oxide nanoparticles (2–20 nm) coated with oleic acid used in this study were synthesized using a simple and inexpensive version of the popular coprecipitation technique. This apparatus uses hexane as a CO 2 gas-expanded liquid to controllably precipitate nanoparticles inside a 1L high-pressure reactor. This paper demonstrates the operation of this new apparatus and for the first time shows the successful fractionation results on a system of metal oxide nanoparticles, with initial nanoparticle concentrations in the gram-scale. The analysis of the obtained fractions was performed using transmission electron microscopy and dynamic light scattering. The use of this simple apparatus provides a pathway to separate large quantities of iron oxide nanoparticles based upon their size for use in various industrial applications.

Electro-oxidation of methanol and formic acid on platinum nanoparticles with different oxidation levels

Energy Technology Data Exchange (ETDEWEB)

Hsieh, Chien-Te, E-mail: cthsieh@saturn.yzu.edu.tw [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan (China); Hsiao, Han-Tsung; Tzou, Dong-Ying; Yu, Po-Yuan [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan (China); Chen, Po-Yen; Jang, Bi-Sheng [Materials and Electro-Optics Research Division, National Chung-Shan Institute of Science and Technology, Taoyuan 325, Taiwan (China)

2015-01-15

Herein reported is an atomic layer deposition (ALD) process of platinum (Pt) from (methylcyclopentadienyl) trimethylplatinum (MeCpPtMe{sub 3}) and oxygen (O{sub 2}) for synthesizing the Pt electrocatalysts toward methanol and formic acid oxidation. The as-synthesized Pt catalysts are thermally reduced in 5 vol% H{sub 2} within temperature window of 150–450 °C. The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species, e.g., PtO and PtO{sub 2}. The presence of Pt–O species not only enhances catalytic activity but also improves anti-poisoning ability toward the oxidation of methanol and formic acid. The improved activity originates from the fact that the Pt–O species, formed by the ALD route, creates a large number of active sites (e.g., Pt–O{sub ads} and Pt–(OH){sub ads}) to strip the CO-adsorbed sites, leading to a high-level of CO tolerance. This work also proposes a stepwise reaction steps to shed some lights on how the Pt–O species promote the catalytic activity. - Highlights: • This study adopts atomic layer deposition (ALD) to grow metallic Pt nanoparticles. • The Pt catalysts show catalytic activity toward methanol and formic acid oxidation. • The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species. • The Pt–O species creates a number of active sites to strip the CO-adsorbed sites. • A stepwise reaction step concerning the promoted catalytic activity is proposed.

Interactive effects of cerium oxide and diesel exhaust nanoparticles on inducing pulmonary fibrosis

Energy Technology Data Exchange (ETDEWEB)

Ma, Jane Y.C., E-mail: jym1@cdc.gov [Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Young, Shih-Houng; Mercer, Robert R.; Barger, Mark; Schwegler-Berry, Diane [Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Ma, Joseph K. [School of Pharmacy, West Virginia University, Morgantown, WV 26506 (United States); Castranova, Vincent [Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States)

2014-07-15

Cerium compounds have been used as a fuel-borne catalyst to lower the generation of diesel exhaust particles (DEPs), but are emitted as cerium oxide nanoparticles (CeO{sub 2}) along with DEP in the diesel exhaust. The present study investigates the effects of the combined exposure to DEP and CeO{sub 2} on the pulmonary system in a rat model. Specific pathogen-free male Sprague–Dawley rats were exposed to CeO{sub 2} and/or DEP via a single intratracheal instillation and were sacrificed at various time points post-exposure. This investigation demonstrated that CeO{sub 2} induces a sustained inflammatory response, whereas DEP elicits a switch of the pulmonary immune response from Th1 to Th2. Both CeO{sub 2} and DEP activated AM and lymphocyte secretion of the proinflammatory cytokines IL-12 and IFN-γ, respectively. However, only DEP enhanced the anti-inflammatory cytokine IL-10 production in response to ex vivo LPS or Concanavalin A challenge that was not affected by the presence of CeO{sub 2}, suggesting that DEP suppresses host defense capability by inducing the Th2 immunity. The micrographs of lymph nodes show that the particle clumps in DEP + CeO{sub 2} were significantly larger than CeO{sub 2} or DEP, exhibiting dense clumps continuous throughout the lymph nodes. Morphometric analysis demonstrates that the localization of collagen in the lung tissue after DEP + CeO{sub 2} reflects the combination of DEP-exposure plus CeO{sub 2}-exposure. At 4 weeks post-exposure, the histological features demonstrated that CeO{sub 2} induced lung phospholipidosis and fibrosis. DEP induced lung granulomas that were not significantly affected by the presence of CeO{sub 2} in the combined exposure. Using CeO{sub 2} as diesel fuel catalyst may cause health concerns. - Highlights: • DEP induced acute lung inflammation and switched immune response from Th1 to Th2. • DEP induced lung granulomas were not affected by the presence of CeO{sub 2}. • CeO{sub 2} induced sustained lung

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.

Effect of the number of iron oxide nanoparticle layers on the magnetic properties of nanocomposite LbL assemblies

International Nuclear Information System (INIS)

Dincer, Ilker; Tozkoparan, Onur; German, Sergey V.; Markin, Alexey V.; Yildirim, Oguz; Khomutov, Gennady B.; Gorin, Dmitry A.; Venig, Sergey B.; Elerman, Yalcin

2012-01-01

Aqueous colloidal suspension of iron oxide nanoparticles has been synthesized. Z-potential of iron oxide nanoparticles stabilized by citric acid was −35±3 mV. Iron oxide nanoparticles have been characterized by the light scattering method and transmission electron microscopy. The polyelectrolyte/iron oxide nanoparticle thin films with different numbers of iron oxide nanoparticle layers have been prepared on the surface of silicon substrates via the layer-by-layer assembly technique. The physical properties and chemical composition of nanocomposite thin films have been studied by atomic force microscopy, magnetic force microscopy, magnetization measurements, Raman spectroscopy. Using the analysis of experimental data it was established, that the magnetic properties of nanocomposite films depended on the number of iron oxide nanoparticle layers, the size of iron oxide nanoparticle aggregates, the distance between aggregates, and the chemical composition of iron oxide nanoparticles embedded into the nanocomposite films. The magnetic permeability of nanocomposite coatings has been calculated. The magnetic permeability values depend on the number of iron oxide nanoparticle layers in nanocomposite film. - Highlights: ► The magnetic properties of nanocomposite films depended on the number of iron oxide nanoparticle layers. ► The iron oxide nanoparticle phase in nanocomposite coatings is a mixture of magnetite and maghemite phases. ► The magnetite and maghemite phases depend on a number of iron oxide nanoparticle layers because the iron oxide nanoparticles are oxidized from magnetite to maghemite.

Environment friendly route of iron oxide nanoparticles from Zingiber officinale (ginger) root extract

Science.gov (United States)

Xin Hui, Yau; Yi Peng, Teoh; Wei Wen, Liu; Zhong Xian, Ooi; Peck Loo, Kiew

2016-11-01

Iron oxide nanoparticles were prepared from the reaction between the Zingiber officinale (ginger) root extracts and ferric chloride solution at 50°C for 2 h in mild stirring condition. The synthesized powder forms of nanoparticles were further characterized by using UV-Vis spectroscopy and X-ray Diffraction spectrometry. UV-Vis analysis shows the absorption peak of iron oxide nanoparticles is appeared at 370 nm. The calculation of crystallite size from the XRD showed that the average particle size of iron oxide nanoparticles was 68.43 nm. Therefore, this eco-friendly technique is low cost and large scale nanoparticles synthesis to fulfill the demand of various applications.

X-Ray Photoelectron Spectroscopic Characterization of Iron Oxide Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Radu, T., E-mail: Teodora.Radu@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293, Cluj Napoca (Romania); Iacovita, C. [Department of Pharmaceutical Physics-Biophysics, Faculty of Pharmacy, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400349, Cluj-Napoca (Romania); Benea, D. [Faculty of Physics, Babes Bolyai University, 400271, Cluj-Napoca (Romania); Turcu, R. [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293, Cluj Napoca (Romania)

2017-05-31

Highlights: • Characterization of three types of iron oxides magnetic nanoparticles. • A correlation between valence band XPS and the degree of iron oxidation is proposed. • Theoretical contributions of Fe in tetragonal and octahedral environment are shown. - Abstract: We report X-ray photoelectron spectroscopy (XPS) results on iron oxide magnetic nanoparticle (Fe{sub 3}O{sub 4}) synthesized using solvothermal reduction in the presence of polyethylene glycol. The magnetite obtained was employed as precursor for the synthesis of γ-Fe{sub 2}O{sub 3} (by oxygen dissociation) which in turn was transformed into α-Fe{sub 2}O{sub 3}. We confirmed the magnetite, maghemite and hematite structure by Fourier Transformed Spectroscopy (FTIR) and X-ray diffraction (XRD). The analysis of the XPS core level and valence band (VB) photoemission spectra for all investigated samples is discussed in terms of the degree of iron oxidation. This is of fundamental importance to better understand the electronic structure of the obtained iron oxide nanoparticles in order to control and improve their quality for specific biomedical applications. Moreover, theoretical band structure calculations are performed for magnetite and the separate contributions of Fe in tetragonal and octahedral environment are shown.

Oxidation effect on templating of metal oxide nanoparticles within block copolymers

International Nuclear Information System (INIS)

Akcora, Pinar; Briber, Robert M.; Kofinas, Peter

2009-01-01

Amphiphilic norbornene-b-(norbornene dicarboxylic acid) diblock copolymers with different block ratios were prepared as templates for the incorporation of iron ions using an ion exchange protocol. The disordered arrangement of iron oxide particles within these copolymers was attributed to the oxidation of the iron ions and the strong interactions between iron oxide nanoparticles, particularly at high iron ion concentrations, which was found to affect the self-assembly of the block copolymer morphologies.

Synthesis and heating effect of iron/iron oxide composite and iron oxide nanoparticles.

Science.gov (United States)

Zeng, Q; Baker, I; Loudis, J A; Liao, Y F; Hoopes, P J

2007-02-09

Fe/Fe oxide nanoparticles, in which the core consists of metallic Fe and the shell is composed of Fe oxides, were obtained by reduction of an aqueous solution of FeCl 3 within a NaBH 4 solution, or, using a water-in-oil micro-emulsion with CTAB as the surfactant. The reduction was performed either in an inert atmosphere or in air, and passivation with air was performed to produce the Fe/Fe 3 O 4 core/shell composite. Phase identification and particle size were determined by X-ray diffraction and TEM. Thermal analysis was performed using a differential scanning calorimeter. The quasistatic magnetic properties were measured using a VSM, and the specific absorption rates (SARs) of both Fe oxide and Fe/Fe 3 O 4 composite nanoparticles either dispersed in methanol or in an epoxy resin were measured by Luxtron fiber temperature sensors in an alternating magnetic field of 150 Oe at 250 kHz. It was found that the preparation conditions, including the concentrations of solutions, the mixing procedure and the heat treatment, influence the particle size, the crystal structure and consequently the magnetic properties of the particles. Compared with Fe oxides, the saturation magnetization ( M S ) of Fe/Fe 3 O 4 particles (100-190 emu/g) can be twice as high, and the coercivity ( H C ) can be tunable from several Oe to several hundred Oe. Hence, the SAR of Fe/Fe 3 O 4 composite nanoparticles can be much higher than that of Fe oxides, with a maximum SAR of 345 W/g. The heating behavior is related to the magnetic behavior of the nanoparticles.

Effects of amorphous silica coating on cerium oxide nanoparticles induced pulmonary responses

International Nuclear Information System (INIS)

Ma, Jane; Mercer, Robert R.; Barger, Mark; Schwegler-Berry, Diane; Cohen, Joel M.; Demokritou, Philip; Castranova, Vincent

2015-01-01

Recently cerium compounds have been used in a variety of consumer products, including diesel fuel additives, to increase fuel combustion efficiency and decrease diesel soot emissions. However, cerium oxide (CeO 2 ) nanoparticles have been detected in the exhaust, which raises a health concern. Previous studies have shown that exposure of rats to nanoscale CeO 2 by intratracheal instillation (IT) induces sustained pulmonary inflammation and fibrosis. In the present study, male Sprague–Dawley rats were exposed to CeO 2 or CeO 2 coated with a nano layer of amorphous SiO 2 (aSiO 2 /CeO 2 ) by a single IT and sacrificed at various times post-exposure to assess potential protective effects of the aSiO 2 coating. The first acellular bronchoalveolar lavage (BAL) fluid and BAL cells were collected and analyzed from all exposed animals. At the low dose (0.15 mg/kg), CeO 2 but not aSiO 2 /CeO 2 exposure induced inflammation. However, at the higher doses, both particles induced a dose-related inflammation, cytotoxicity, inflammatory cytokines, matrix metalloproteinase (MMP)-9, and tissue inhibitor of MMP at 1 day post-exposure. Morphological analysis of lung showed an increased inflammation, surfactant and collagen fibers after CeO 2 (high dose at 3.5 mg/kg) treatment at 28 days post-exposure. aSiO 2 coating significantly reduced CeO 2 -induced inflammatory responses in the airspace and appeared to attenuate phospholipidosis and fibrosis. Energy dispersive X-ray spectroscopy analysis showed Ce and phosphorous (P) in all particle-exposed lungs, whereas Si was only detected in aSiO 2 /CeO 2 -exposed lungs up to 3 days after exposure, suggesting that aSiO 2 dissolved off the CeO 2 core, and some of the CeO 2 was transformed to CePO 4 with time. These results demonstrate that aSiO 2 coating reduce CeO 2 -induced inflammation, phospholipidosis and fibrosis. - Highlights: • Both CeO 2 and aSiO 2 /CeO 2 particles were detected in the respective particle-exposed lungs. • The

Synthesis and luminescent properties of PEO/lanthanide oxide nanoparticle hybrid films

International Nuclear Information System (INIS)

Goubard, F.; Vidal, F.; Bazzi, R.; Tillement, O.; Chevrot, C.; Teyssie, D.

2007-01-01

In this study, we investigate the optical properties of lanthanide oxide nanoparticles dispersed in poly(ethylene oxide) (PEO) network as thermally stable polymeric films. The aim of this work is both to keep a good optical transparency in the visible domain and to obtain luminescent materials after incorporation of nanoparticles. For this purpose, we develop luminescent nanocrystals of oxides containing terbium ion as a doping element in Gd 2 O 3 . These sub-5-nm lanthanide oxides nanoparticles have been prepared by direct oxide precipitation in high-boiling polyalcohol solutions and characterized by luminescence spectroscopy. PEO/lanthanide oxide nanohybrid films are prepared by radical polymerization of poly(ethylene glycol) methacrylate after introduction of lanthanide oxide particles. As a first result; the obtained films present interesting luminescence properties with a very low lanthanide oxide content (up to 0.29 wt%). Furthermore, these films are still transparent and keep their original mechanical properties. Prior to describe the specific applications to optical use, we report here the dynamic mechanical analysis (DMA), X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), and luminescent properties of. nanohybrid films

Toxic Effects of Nickel Oxide Bulk and Nanoparticles on the Aquatic Plant Lemna gibba L.

Directory of Open Access Journals (Sweden)

Abdallah Oukarroum

2015-01-01

Full Text Available The aquatic plant Lemna gibba L. was used to investigate and compare the toxicity induced by 30 nm nickel oxide nanoparticles (NiO-NPs and nickel(II oxide as bulk (NiO-Bulk. Plants were exposed during 24 h to 0–1000 mg/L of NiO-NPs or NiO-Bulk. Analysis of physicochemical characteristics of nanoparticles in solution indicated agglomerations of NiO-NPs in culture medium and a wide size distribution was observed. Both NiO-NPs and NiO-Bulk caused a strong increase in reactive oxygen species (ROS formation, especially at high concentration (1000 mg/L. These results showed a strong evidence of a cellular oxidative stress induction caused by the exposure to NiO. Under this condition, NiO-NPs and NiO-Bulk induced a strong inhibitory effect on the PSII quantum yield, indicating an alteration of the photosynthetic electron transport performance. Under the experimental conditions used, it is clear that the observed toxicity impact was mainly due to NiO particles effect. Therefore, results of this study permitted determining the use of ROS production as an early biomarker of NiO exposure on the aquatic plant model L. gibba used in toxicity testing.

Characterization of injected aluminum oxide nanoparticle clouds in an rf discharge

Science.gov (United States)

Krüger, Harald; Killer, Carsten; Schütt, Stefan; Melzer, André

2018-02-01

An experimental setup to deagglomerate and insert nanoparticles into a radio frequency discharge has been developed to confine defined aluminum oxide nanoparticles in a dusty plasma. For the confined particle clouds we have measured the spatially resolved in situ size and density distributions. Implementing the whole plasma chamber into the sample volume of an FTIR spectrometer the infrared spectrum of the confined aluminum oxide nanoparticles has been obtained. We have investigated the dependency of the absorbance of the nanoparticles in terms of plasma power, pressure and cloud shape. The particles’ infrared phonon resonance has been identified.

Characterization of the oleic acid/iron oxide nanoparticle interface by magnetic resonance

Energy Technology Data Exchange (ETDEWEB)

Masur, S., E-mail: sabrina.masur@uni-due.de; Zingsem, B.; Marzi, T.; Meckenstock, R.; Farle, M.

2016-10-01

The synthesis of colloidal nanoparticles involves surfactant molecules, which bind to the particle surface and stabilize nanoparticles against aggregation. In many cases these protecting shells also can be used for further functionalization. In this study, we investigated monodisperse single crystalline iron oxide core/shell nanoparticles (Fe{sub x}O{sub y}-NPs) in situ covered with an oleic acid layer which showed two electron spin resonance (ESR) signals. The nanoparticles with the ligands attached were characterized by transmission electron microscopy (TEM) and ferro- and paramagnetic resonance (FMR, EPR). Infrared spectroscopy confirmed the presence of the functional groups and revealed that the oleic acid (OA) is chemisorbed as a carboxylate on the iron oxide and is coordinated symmetrically to the oxide atoms. We show that the EPR signal of the OA ligand molecule can be used as a local probe to determine the temperature changes at the surface of the nanoparticle. - Highlights: • Monodisperse single crystalline iron oxide core/shell nanoparticles (Fe{sub x}O{sub y}-NPs) in situ covered with an oleic acid layer two electron spin resonance (ESR) signals. • We show that the EPR signal of the OA ligand molecule can be used as a local probe to determine the temperature changes at the surface of the nanoparticle.

Weak ferromagnetism and exchange biasing in cobalt oxide nanoparticle systems

NARCIS (Netherlands)

Tomou, A; Gournis, D; Panagiotopoulos, [No Value; Huang, Y; Hadjipanayis, GC; Kooi, BJ; Panagiotopoulos, I.

2006-01-01

Cobalt oxide nanoparticle systems have been prepared by wet chemical processing involving the encapsulation of the nanoparticles by an organic ligand shell (oleic acid and oleylamine). CoO nanoparticles were easily prepared by this method, while the synthesis of the CoPt/CoO nanocomposites was

Synthesis and functionalisation of metal and metal oxide nanoparticles for theranostics

OpenAIRE

Mundell, VJ

2013-01-01

Metal and metal oxide nanoparticles including calcium oxide, gold, and superparamagnetic iron oxide nanoparticles (SPIOs) were synthesised using a range of techniques including reduction, co-precipitation and spinning disc technology. SPIOs were primarily synthesised via a co-precipitation method using iron (II) chloride, iron (III) chloride and ammonia; a spinning disc reactor and gaseous ammonia were trialled successfully for scale up, producing spherical particles of 10-40 nm in diameter a...

The Green Synthesis and Evaluation of Silver Nanoparticles and Zinc Oxide Nanoparticles

Science.gov (United States)

Gebear-Eigzabher, Bellsabel

Nanoparticle (NP) research has received exceptional attention as the field of study that contributes to transforming the world of materials science. When implementing NPs in consumer and industrial products, their unique properties improve technologies to the extent of significant game-changing breakthroughs. Conversely, the increased production of NPs, their use, their disposal or inadvertent release in the environment drove the need for processes and policies that ensures consumer and environmental safety. Mitigation of any harmful effects that NPs could potentially have combines methods of safe preparation, safe handling and safe disposal as well as containment of any inadvertent release. Our focus is in safe preparation of nanomaterials and we report green and energy efficient synthesis methods for metal NPs and metal oxide NPs of two popular materials: silver (Ag) and zinc oxide (ZnO). The thesis explained: 1) The impact of NPs in nowadays' world; 2) Synthesis methods that were designed to include environmentally-friendly staring materials and energy-saving fabrication processes, with emphasis on maintaining NPs final size and morphology when compared with existing methods; and 3) Nanoparticles characterization and data collection which allowed us to determine and/or validate their properties. Nanoparticles were studied using transmission electron microscope (TEM), X-Ray powder diffraction (XRD), low-voltage (5 keV) transmission electron microscopy (LV EM 5), Fourier-Transform Infrared Spectroscopy (FT-IR), and Ultraviolet-Visible (UV-Vis) spectroscopy. We developed an aqueous-based preparation of zinc oxide nanoparticles (ZnO NPs) using microwave-assisted chemistry to render a well-controlled particle size distribution within each set of reaction conditions in the range of 15 nm to 75 nm. We developed a scalable silver nanoparticles synthesis by chemical reduction methods. The NPs could be used in consumer products. The measurement tools for consumer products

Host thin films incorporating nanoparticles

Science.gov (United States)

Qureshi, Uzma

The focus of this research project was the investigation of the functional properties of thin films that incorporate a secondary nanoparticulate phase. In particular to assess if the secondary nanoparticulate material enhanced a functional property of the coating on glass. In order to achieve this, new thin film deposition methods were developed, namely use of nanopowder precursors, an aerosol assisted transport technique and an aerosol into atmospheric pressure chemical vapour deposition system. Aerosol assisted chemical vapour deposition (AACVD) was used to deposit 8 series of thin films on glass. Five different nanoparticles silver, gold, ceria, tungsten oxide and zinc oxide were tested and shown to successfully deposit thin films incorporating nanoparticles within a host matrix. Silver nanoparticles were synthesised and doped within a titania film by AACVD. This improved solar control properties. A unique aerosol assisted chemical vapour deposition (AACVD) into atmospheric pressure chemical vapour deposition (APCVD) system was used to deposit films of Au nanoparticles and thin films of gold nanoparticles incorporated within a host titania matrix. Incorporation of high refractive index contrast metal oxide particles within a host film altered the film colour. The key goal was to test the potential of nanopowder forms and transfer the suspended nanopowder via an aerosol to a substrate in order to deposit a thin film. Discrete tungsten oxide nanoparticles or ceria nanoparticles within a titanium dioxide thin film enhanced the self-cleaning and photo-induced super-hydrophilicity. The nanopowder precursor study was extended by deposition of zinc oxide thin films incorporating Au nanoparticles and also ZnO films deposited from a ZnO nanopowder precursor. Incorporation of Au nanoparticles within a VO: host matrix improved the thermochromic response, optical and colour properties. Composite VC/TiC and Au nanoparticle/V02/Ti02 thin films displayed three useful

Genotoxic effects of zinc oxide nanoparticles

Science.gov (United States)

Heim, Julia; Felder, Eva; Tahir, Muhammad Nawaz; Kaltbeitzel, Anke; Heinrich, Ulf Ruediger; Brochhausen, Christoph; Mailänder, Volker; Tremel, Wolfgang; Brieger, Juergen

2015-05-01

The potential toxicity of nanoparticles has currently provoked public and scientific discussions, and attempts to develop generally accepted handling procedures for nanoparticles are under way. The investigation of the impact of nanoparticles on human health is overdue and reliable test systems accounting for the special properties of nanomaterials must be developed. Nanoparticular zinc oxide (ZnO) may be internalised through ambient air or the topical application of cosmetics, only to name a few, with unpredictable health effects. Therefore, we analysed the determinants of ZnO nanoparticle (NP) genotoxicity. ZnO NPs (15-18 nm in diameter) were investigated at concentrations of 0.1, 10 and 100 μg mL-1 using the cell line A549. Internalised NPs were only infrequently detectable by TEM, but strongly increased Zn2+ levels in the cytoplasm and even more in the nuclear fraction, as measured by atom absorption spectroscopy, indicative of an internalised zinc and nuclear accumulation. We observed a time and dosage dependent reduction of cellular viability after ZnO NP exposure. ZnCl2 exposure to cells induced similar impairments of cellular viability. Complexation of Zn2+ with diethylene triamine pentaacetic acid (DTPA) resulted in the loss of toxicity of NPs, indicating the relevant role of Zn2+ for ZnO NP toxicity. Foci analyses showed the induction of DNA double strand breaks (DSBs) by ZnO NPs and increased intracellular reactive oxygen species (ROS) levels. Treatment of the cells with the ROS scavenger N-acetyl-l-cysteine (NAC) resulted in strongly decreased intracellular ROS levels and reduced DNA damage. However, a slow increase of ROS after ZnO NP exposure and reduced but not quashed DSBs after NAC-treatment suggest that Zn2+ may exert genotoxic activities without the necessity of preceding ROS-induction. Our data indicate that ZnO NP toxicity is a result of cellular Zn2+ intake. Subsequently increased ROS-levels cause DNA damage. However, we found evidence for

Single step radiolytic synthesis of iridium nanoparticles onto graphene oxide

International Nuclear Information System (INIS)

Rojas, J.V.; Molina Higgins, M.C.; Toro Gonzalez, M.; Castano, C.E.

2015-01-01

Graphical abstract: - Highlights: • Ir nanoparticles were synthesized through a single step gamma irradiation process. • Homogeneously distributed Ir nanoparticles on graphene oxide are ∼2.3 nm in size. • Ir−O bonds evidenced the interaction of the nanoparticles with the support. - Abstract: In this work a new approach to synthesize iridium nanoparticles on reduced graphene oxide is presented. The nanoparticles were directly deposited and grown on the surface of the carbon-based support using a single step reduction method through gamma irradiation. In this process, an aqueous isopropanol solution containing the iridium precursor, graphene oxide, and sodium dodecyl sulfate was initially prepared and sonicated thoroughly to obtain a homogeneous dispersion. The samples were irradiated with gamma rays with energies of 1.17 and 1.33 MeV emitted from the spontaneous decay of the 60 Co irradiator. The interaction of gamma rays with water in the presence of isopropanol generates highly reducing species homogeneously distributed in the solution that can reduce the Ir precursor down to a zero valence state. An absorbed dose of 60 kGy was used, which according to the yield of reducing species is sufficient to reduce the total amount of precursor present in the solution. This novel approach leads to the formation of 2.3 ± 0.5 nm Ir nanoparticles distributed along the surface of the support. The oxygenated functionalities of graphene oxide served as nucleation sites for the formation of Ir nuclei and their subsequent growth. XPS results revealed that the interaction of Ir with the support occurs through Ir−O bonds.

Synthesis of oxidation resistant lead nanoparticle films by modified pulsed laser ablation

Energy Technology Data Exchange (ETDEWEB)

Shin, Eunsung; Murray, P. Terrence; Subramanyam, Guru; Malik, Hans K.; Schwartz, Kenneth L. [Research Institute, University of Dayton, Dayton, OH 45469-0170 (United States); Research Institute, University of Dayton, Dayton, OH 45469-0170, USA and Graduate Materials Engineering, University of Dayton, Dayton, OH 45469-0240 (United States); Department of Electrical and Computer Engineering, University of Dayton, Dayton, OH 45469-0232 (United States); Northrop Grumman Electronic Systems, Linthicum, MD 21090 (United States)

2012-07-30

Thin layers of lead nanoparticles have been produced by a modified pulsed laser ablation (PLA) process in which smaller nanoparticles were swept out of the ablation chamber by a stream of flowing Ar. Large ({mu}m-sized) particles, which are usually deposited during the standard PLA process, were successfully eliminated from the deposit. The nanoparticles deposited on room temperature substrates were well distributed, and the most probable particle diameter was in the order of 30 nm. Since lead is highly reactive, the nanoparticles formed in Ar were quickly oxidized upon exposure to air. A small partial pressure of H{sub 2}S gas was subsequently added to the effluent, downstream from the ablation chamber, and this resulted in the formation of nanoparticle deposits that were surprisingly oxidation resistant. The properties of the nanoparticle films (as determined by transmission electron microscopy, scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and conductivity measurements) are reported, and the mechanism of the oxidation retardation process is discussed.

Multiwalled Carbon Nanotubes Decorated with Cobalt Oxide Nanoparticles

Directory of Open Access Journals (Sweden)

D. G. Larrude

2012-01-01

Full Text Available Multiwalled carbon nanotubes (MWCNTs synthesized by spray pyrolysis were decorated with cobalt oxide nanoparticles using a simple synthesis route. This wet chemistry method yielded nanoparticles randomly anchored to the surface of the nanotubes by decomposition of cobalt nitrate hexahydrate diluted in acetone. Electron microscopy analysis indicated that dispersed particles were formed on the MWCNTs walls. The average size increased with the increasing concentration of cobalt nitrate in acetone in the precursor mixture. TEM images indicated that nanoparticles were strongly attached to the tube walls. The Raman spectroscopy results suggested that the MWCNT structure was slightly damaged after the nanoparticle growth.

Cytotoxic Effect of Iron Oxide Nanoparticles on Mouse Embryonic Stem Cells by MTT Assay

Directory of Open Access Journals (Sweden)

Homa Mohseni Kouchesfehani

2016-07-01

Full Text Available Background: Despite the wide range of applications, there is a serious lack of information on the impact of the nanoparticles on human health and the environment. The present study was done to determine the range of dangerous concentrations of iron oxide nanoparticle and their effects on mouse embryonic stem cells. Methods: Iron oxide nanoparticles with less than 20 nanometers diameter were encapsulated by a PEG-phospholipid. The suspension of iron oxide nanoparticles was prepared using the culture media and cell viability was determined by MTT assay. Results: MTT assay was used to examine the cytotoxicity of iron oxide nanoparticle s. Royan B1 cells were treated with medium containing different concentrations (10, 20, 30, 40, 50, and 60µg/ml of the iron oxide nanoparticle. Cell viability was determined at 12 and 24 hours after treatment which showed significant decreases when concentration and time period increased. Conclusion: The main mechanism of nanoparticles action is still unknown, but in vivo and in vitro studies in different environments suggest that they are capable of producing reactive oxygen species (ROS. Therefore, they may have an effect on the concentration of intracellular calcium, activation of transcription factors, and changes in cytokine. The results of this study show that the higher concentration and duration of treatment of cells with iron oxide nanoparticles increase the rate of cell death.

CHEMISTRY OF SO2 AND DESOX PROCESSES ON OXIDE NANOPARTICLES.

Energy Technology Data Exchange (ETDEWEB)

RODRIGUEZ, J.A.

2006-06-30

On bulk stoichiometric oxides, SO{sub 2} mainly reacts with the O centers to form SO{sub 3} or SO{sub 4} species that decompose at elevated temperatures. Adsorption on the metal cations occurs below 300 K and does not lead to cleavage of the S-O bonds. In bulk oxides, the occupied cation bands are too stable for effective bonding interactions with the LUMO of SO{sub 2}. The effects of quantum confinement on the electronic properties of oxide nanoparticles and the structural defects that usually accompany these systems in general favor the bonding and dissociation of SO{sub 2}. Thus, nanoparticles of MgO, CaO, SrO, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3} and CeO{sub 2} are all more efficient for sequestering SO{sub 2} than the corresponding bulk oxides. Structural imperfections in pure or metal-doped ceria nanoparticles accelerate the reduction of SO{sub 2} by CO by facilitating the formation and migration of O vacancies in the oxide surface.

Synthesis of Monodisperse Iron Oxide Nanoparticles without Surfactants

Directory of Open Access Journals (Sweden)

Xiao-Chen Yang

2014-01-01

Full Text Available Monodisperse iron oxide nanoparticles could be successfully synthesized with two kinds of precipitants through a precipitation method. As-prepared nanoparticles in the size around 10 nm with regular spherical-like shape were achieved by adjusting pH values. NaOH and NH3·H2O were used as two precipitants for comparison. The average size of nanoparticles with NH3·H2O precipitant got smaller and represented better dispersibility, while nanoparticles with NaOH precipitant represented better magnetic property. This work provided a simple method without using any organic solvents, organic metal salts, or surfactants which could easily obtain monodisperse nanoparticles with tunable morphology.

Doxorubicin loaded PVA coated iron oxide nanoparticles for targeted drug delivery

International Nuclear Information System (INIS)

Kayal, S.; Ramanujan, R.V.

2010-01-01

Magnetic drug targeting is a drug delivery system that can be used in locoregional cancer treatment. Coated magnetic particles, called carriers, are very useful for delivering chemotherapeutic drugs. Magnetic carriers were synthesized by coprecipitation of iron oxide followed by coating with polyvinyl alcohol (PVA). Characterization was carried out using X-ray diffraction, TEM, TGA, FTIR and VSM techniques. The magnetic core of the carriers was magnetite (Fe 3 O 4 ), with average size of 10 nm. The room temperature VSM measurements showed that magnetic particles were superparamagnetic. The amount of PVA bound to the iron oxide nanoparticles were estimated by thermogravimetric analysis (TGA) and the attachment of PVA to the iron oxide nanoparticles was confirmed by FTIR analysis. Doxorubicin (DOX) drug loading and release profiles of PVA coated iron oxide nanoparticles showed that up to 45% of adsorbed drug was released in 80 h, the drug release followed the Fickian diffusion-controlled process. The binding of DOX to the PVA was confirmed by FTIR analysis. The present findings show that DOX loaded PVA coated iron oxide nanoparticles are promising for magnetically targeted drug delivery.

Zinc oxide nanoparticles as novel alpha-amylase inhibitors

Science.gov (United States)

Dhobale, Sandip; Thite, Trupti; Laware, S. L.; Rode, C. V.; Koppikar, Soumya J.; Ghanekar, Ruchika-Kaul; Kale, S. N.

2008-11-01

Amylase inhibitors, also known as starch blockers, contain substances that prevent dietary starches from being absorbed by the body via inhibiting breakdown of complex sugars to simpler ones. In this sense, these materials are projected as having potential applications in diabetes control. In this context, we report on zinc oxide nanoparticles as possible alpha-amylase inhibitors. Zinc oxide nanoparticles have been synthesized using soft-chemistry approach and 1-thioglycerol was used as a surfactant to yield polycrystalline nanoparticles of size ˜18 nm, stabilized in wurtzite structure. Conjugation study and structural characterization have been done using x-ray diffraction technique, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and transmission electron microscopy. Cytotoxicity studies on human fibrosarcoma (HT-1080) and skin carcinoma (A-431) cell lines as well as mouse primary fibroblast cells demonstrate that up to a dose of 20 μg/ml, ZnO nanoparticles are nontoxic to the cells. We report for the first time the alpha-amylase inhibitory activity of ZnO nanoparticles wherein an optimum dose of 20 μg/ml was sufficient to exhibit 49% glucose inhibition at neutral pH and 35 °C temperature. This inhibitory activity was similar to that obtained with acarbose (a standard alpha-amylase inhibitor), thereby projecting ZnO nanoparticles as novel alpha-amylase inhibitors.

Effect of surfactant for magnetic properties of iron oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Haracz, S. [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland); Hilgendorff, M. [Freie Universität Berlin, Fachbereich Physik, Arnimalle 14, 14195 Berlin (Germany); Rybka, J.D. [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland); Giersig, M. [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland); Freie Universität Berlin, Fachbereich Physik, Arnimalle 14, 14195 Berlin (Germany)

2015-12-01

Highlights: • Dynamic behavior of magnetic nanoparticles. • Synthesis of iron oxide nanoparticles. • Effect of surfactant for magnetic properties. - Abstract: For different medical applications nanoparticles (NPs) with well-defined magnetic properties have to be used. Coating ligand can change the magnetic moment on the surface of nanostructures and therefore the magnetic behavior of the system. Here we investigated magnetic NPs in a size of 13 nm conjugated with four different kinds of surfactants. The surface anisotropy and the magnetic moment of the system were changed due to the presence of the surfactant on the surface of iron oxide NPs.

Effects of aluminium oxide nanoparticles on bacterial growth

Directory of Open Access Journals (Sweden)

Doskocz Nina

2017-01-01

Full Text Available Production and wide application of nanomaterials have led to nanotechnology development but their release to environment and the induction of toxic reactions, affects the natural microbial communities. Therefore, studies on the impact of nanoparticles on microorganisms and environment are required and needed. The aim of this study was to assess the impact of aluminium oxide nanoparticles on the growth of Pseudomonas putida. To compare the harmfulness of different forms of aluminium oxide, the ecotoxicity of its macro-forms was also evaluated in the study. Research showed that the exposure to nanoparticles can negatively influence microorganisms. The EC50-16h determined in this study was 0.5 mg/l, and NOEC equaled 0.19 mg/l. Nano-Al2O3 proved to be more toxic to P. putida than aluminium oxide. This indicates that the nano-form of a given substance demonstrates different properties and may constitute a far greater danger for the environment than the same substance in the large form. According to EU and US EPA criteria, nano-Al2O3 proved to be very toxic and highly toxic, respectively. Changes in bacterial communities caused by nanoparticles may affect the normal biological, chemical and nutrient cycle in the ecosystem and the effect triggered by nanomaterials in relation to other organisms is unpredictable.

Colloidosome-based synthesis of a multifunctional nanostructure of silver and hollow iron oxide nanoparticles

KAUST Repository

Pan, Yue

2010-03-16

Nanoparticles that self-assemble on a liquid-liquid interface serve as the building block for making heterodimeric nanostructures. Specifically, hollow iron oxide nanoparticles within hexane form colloidosomes in the aqueous solution of silver nitrate, and iron oxide exposed to the aqueous phase catalyzes the reduction of silver ions to afford a heterodimer of silver and hollow iron oxide nanoparticles. Transmission electron microscopy, selected area electron diffraction, energy-dispersive X-ray spectrometry, X-ray diffraction, UV-vis spectroscopy, and SQUID were used to characterize the heterodimers. Interestingly, the formation of silver nanoparticles helps the removal of spinglass layer on the hollow iron oxide nanoparticles. This work demonstrates a powerful yet convenient strategy for producing sophisticated, multifunctional nanostructures. © 2010 American Chemical Society.

The development of latent fingerprints by zinc oxide and tin oxide nanoparticles prepared by precipitation technique

Science.gov (United States)

Luthra, Deepali; Kumar, Sacheen

2018-05-01

Fingerprints are the very important evidence at the crime scene which must be developed clearly with shortest duration of time to solve the case. Metal oxide nanoparticles could be the mean to develop the latent fingerprints. Zinc oxide and Tin Oxide Nanoparticles were prepared by using chemical precipitation technique which were dried and characterized by X-ray diffraction, UV-Visible spectroscopy and FTIR. The size of zinc oxide crystallite was found to be 14.75 nm with minimum reflectance at 360 nm whereas tin oxide have the size of 90 nm and reflectance at minimum level 321 nm. By using these powdered samples on glass, plastic and glossy cardboard, latent fingerprints were developed. Zinc oxide was found to be better candidate than tin oxide for the fingerprint development on all the three types of substrates.

Photoactive nanocomplex formed from chlorophyll assembly on TMA-coated iron oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Barbaros, Sibel; Meray, Zeynep; Tecim, Tuğba; Genç, Rükan, E-mail: rukangnc@gmail.com [Mersin University, Functional Nanomaterials Laboratory, Chemical Engineering Department, Engineering Faculty (Turkey)

2016-07-15

In this study, hierarchical self-assembly of photocatalytic nanodisks through non-covalent interactions between spinach-extracted chlorophyll molecules and trimethylammonium hydroxide-coated magnetic iron oxide nanoparticles was discussed. Combination of chlorophyll molecules with iron oxide nanoparticles generated an alteration in light absorption at both visible and near-IR region with accompanying enhancement in fluorescence emission. Further, photocatalytic role of resulting molecular assembly was studied by means of the photoinduced degradation of methylene blue dye under UV light and direct sun irradiation at neutral pH. In order to enhance the long-term stability of the hybrid nanocatalyst, commercially available cellulose membrane was used as a support and magnetic recovery and reusability was achieved where the nanocatalyst retained more than 90 % of its efficiency even after four cycles. This simple strategy could initiate the development of new materials for wastewater treatment including membrane-based technologies. On the other hand, their sunlight-induced photocatalytic activity could easily be conducted to dye-synthesized solar cells or their enhanced photoluminescence can provide a strong basis for future bioimaging tools.Graphical Abstract.

Non-immunogenic dextran-coated superparamagnetic iron oxide nanoparticles: a biocompatible, size-tunable contrast agent for magnetic resonance imaging.

Science.gov (United States)

Unterweger, Harald; Janko, Christina; Schwarz, Marc; Dézsi, László; Urbanics, Rudolf; Matuszak, Jasmin; Őrfi, Erik; Fülöp, Tamás; Bäuerle, Tobias; Szebeni, János; Journé, Clément; Boccaccini, Aldo R; Alexiou, Christoph; Lyer, Stefan; Cicha, Iwona

2017-01-01

Iron oxide-based contrast agents have been in clinical use for magnetic resonance imaging (MRI) of lymph nodes, liver, intestines, and the cardiovascular system. Superparamagnetic iron oxide nanoparticles (SPIONs) have high potential as a contrast agent for MRI, but no intravenous iron oxide-containing agents are currently approved for clinical imaging. The aim of our work was to analyze the hemocompatibility and immuno-safety of a new type of dextran-coated SPIONs (SPIONdex) and to characterize these nanoparticles with ultra-high-field MRI. Key parameters related to nanoparticle hemocompatibility and immuno-safety were investigated in vitro and ex vivo. To address concerns associated with hypersensitivity reactions to injectable nanoparticulate agents, we analyzed complement activation-related pseudoallergy (CARPA) upon intravenous administration of SPIONdex in a pig model. Furthermore, the size-tunability of SPIONdex and the effects of size reduction on their biocompatibility were investigated. In vitro, SPIONdex did not induce hemolysis, complement or platelet activation, plasma coagulation, or leukocyte procoagulant activity, and had no relevant effect on endothelial cell viability or endothelial-monocytic cell interactions. Furthermore, SPIONdex did not induce CARPA even upon intravenous administration of 5 mg Fe/kg in pigs. Upon SPIONdex administration in mice, decreased liver signal intensity was observed after 15 minutes and was still detectable 24 h later. In addition, by changing synthesis parameters, a reduction in particle size contrast agent.

In vitro assessment of the antimicrobial activity of silver and zinc oxide nanoparticles against fish pathogens.

Science.gov (United States)

Shaalan, Mohamed Ibrahim; El-Mahdy, Magdy Mohamed; Theiner, Sarah; El-Matbouli, Mansour; Saleh, Mona

2017-07-21

Antibiotic resistance is a global issue that threatens public health. The excessive use of antibiotics contributes to this problem as the genes of antibiotic resistance can be transferred between the bacteria in humans, animals and aquatic organisms. Metallic nanoparticles could serve as future substitutes for some conventional antibiotics because of their antimicrobial activity. The aim of this study was to evaluate the antimicrobial effects of silver and zinc oxide nanoparticles against major fish pathogens and assess their safety in vitro. Silver nanoparticles were synthesized by chemical reduction and characterized with UV-Vis spectroscopy, transmission electron microscopy and zeta sizer. The concentrations of silver and zinc oxide nanoparticles were measured using inductively coupled plasma-mass spectrometry. Subsequently, silver and zinc oxide nanoparticles were tested for their antimicrobial activity against Aeromonas hydrophila, Aeromonas salmonicida subsp. salmonicida, Edwardsiella ictaluri, Edwardsiella tarda, Francisella noatunensis subsp. orientalis, Yersinia ruckeri and Aphanomyces invadans and the minimum inhibitory concentrations were determined. MTT assay was performed on eel kidney cell line (EK-1) to determine the cell viability after incubation with nanoparticles. The interaction between silver nanoparticles and A. salmonicida was investigated by transmission electron microscopy. The tested nanoparticles exhibited marked antimicrobial activity. Silver nanoparticles inhibited the growth of both A. salmonicida and A. invadans at a concentration of 17 µg/mL. Zinc oxide nanoparticles inhibited the growth of A. salmonicida, Y. ruckeri and A. invadans at concentrations of 15.75, 31.5 and 3.15 µg/mL respectively. Silver nanoparticles showed higher cell viability when compared to zinc oxide nanoparticles in the MTT assay. Transmission electron microscopy showed the attachment of silver nanoparticles to the bacterial membrane and disruption of its

Effects of silver nanoparticles to soil invertebrates: Oxidative stress biomarkers in Eisenia fetida

International Nuclear Information System (INIS)

Gomes, Susana I.L.; Hansen, Ditte; Scott-Fordsmand, Janeck J.; Amorim, Mónica J.B.

2015-01-01

Silver nanoparticles (Ag-NPs) are among the most produced NPs worldwide having several applications in consumer products. Ag-NPs are known to cause oxidative stress in several organisms and cell lines, however comparatively less information is available regarding their effects on soil living invertebrates. The purpose of this study was to investigate if Ag-NPs cause oxidative stress on soil invertebrates. The model soil species Eisenia fetida was used. Our results showed that total glutathione (TG) is the first mechanism triggered by Ag-NPs, followed by glutathione peroxidase (GPx) and glutathione reductase (GR), however oxidative damage was observed for higher doses and exposure time (increased lipid peroxidation, LPO). AgNO 3 exposure caused impairment in GPx and glutathione-S-transferase (GST), probably as result of the higher bioavailability of Ag in the salt-form. The current results indicate that effects are partly caused by Ag ions released from Ag-NPs, but specific particle effects cannot be excluded. - Highlights: • Oxidative stress of Ag-NPs and AgNO 3 was assessed in Eisenia fetida. • Both Ag forms induced oxidative damage (LPO) via different mechanisms. • Ag-NPs activated total glutathione, followed by GPx and GR. • AgNO 3 impaired GPx and GST. • Overall results indicated effects from Ag ionization and NPs specific effects. - Oxidative stress to Ag in Eisenia fetida occurs via different mechanisms for Ag nanoparticles and AgNO 3

Progress in electrochemical synthesis of magnetic iron oxide nanoparticles

International Nuclear Information System (INIS)

Ramimoghadam, Donya; Bagheri, Samira; Hamid, Sharifah Bee Abd

2014-01-01

Recently, magnetic iron oxide particles have been emerged as significant nanomaterials due to its extensive range of application in various fields. In this regard, synthesis of iron oxide nanoparticles with desirable properties and high potential applications are greatly demanded. Therefore, investigation on different iron oxide phases and their magnetic properties along with various commonly used synthetic techniques are remarked and thoroughly described in this review. Electrochemical synthesis as a newfound method with unique advantages is elaborated, followed by design approaches and key parameters to control the properties of the iron oxide nanoparticles. Additionally, since the dispersion of iron oxide nanoparticles is as important as its preparation, surface modification issue has been a serious challenge which is comprehensively discussed using different surfactants. Despite the advantages of the electrochemical synthesis method, this technique has been poorly studied and requires deep investigations on effectual parameters such as current density, pH, electrolyte concentration etc. - Highlights: • IONPs are applied in chemical industries, medicine, magnetic storage etc. • Electrochemical synthesis (EC) is convenient, eco-friendly, selective and low-cost. • EC key factors are current density, pH, electrolyte concentration, electrode type. • Organic, inorganic and biological materials can be used to modify IONPs’ surface. • The physicochemical properties of IONPs can be controlled by adding surfactants

Scalable fractionation of iron oxide nanoparticles using a CO{sub 2} gas-expanded liquid system

Energy Technology Data Exchange (ETDEWEB)

Vengsarkar, Pranav S.; Xu, Rui; Roberts, Christopher B., E-mail: croberts@eng.auburn.edu [Auburn University, Department of Chemical Engineering (United States)

2015-10-15

Iron oxide nanoparticles exhibit highly size-dependent physicochemical properties that are important in applications such as catalysis and environmental remediation. In order for these size-dependent properties to be effectively harnessed for industrial applications scalable and cost-effective techniques for size-controlled synthesis or size separation must be developed. The synthesis of monodisperse iron oxide nanoparticles can be a prohibitively expensive process on a large scale. An alternative involves the use of inexpensive synthesis procedures followed by a size-selective processing technique. While there are many techniques available to fractionate nanoparticles, many of the techniques are unable to efficiently fractionate iron oxide nanoparticles in a scalable and inexpensive manner. A scalable apparatus capable of fractionating large quantities of iron oxide nanoparticles into distinct fractions of different sizes and size distributions has been developed. Polydisperse iron oxide nanoparticles (2–20 nm) coated with oleic acid used in this study were synthesized using a simple and inexpensive version of the popular coprecipitation technique. This apparatus uses hexane as a CO{sub 2} gas-expanded liquid to controllably precipitate nanoparticles inside a 1L high-pressure reactor. This paper demonstrates the operation of this new apparatus and for the first time shows the successful fractionation results on a system of metal oxide nanoparticles, with initial nanoparticle concentrations in the gram-scale. The analysis of the obtained fractions was performed using transmission electron microscopy and dynamic light scattering. The use of this simple apparatus provides a pathway to separate large quantities of iron oxide nanoparticles based upon their size for use in various industrial applications.

Conductometric gas sensors based on metal oxides modified with gold nanoparticles: a review

International Nuclear Information System (INIS)

Korotcenkov, Ghenadii; Cho, Beong K.; Brinzari, Vladimir

2016-01-01

This review (with 170 refs.) discusses approaches towards surface functionalizaton of metal oxides by gold nanoparticles, and the application of the resulting nanomaterials in resistive gas sensors. The articles is subdivided into sections on (a) methods for modification of metal oxides with gold nanoparticles; (b) the response of gold nanoparticle-modified metal oxide sensors to gaseous species, (c) a discussion of the limitations of such sensors, and (d) a discussion on future tasks and trends along with an outlook. It is shown that, in order to achieve significant improvements in sensor parameters, it is necessary to warrant a good control the size and density of gold nanoparticles on the surface of metal oxide crystallites, the state of gold in the cluster, and the properties of the metal oxide support. Current challenges include an improved reproducibility of sensor preparation, better long-term stabilities, and a better resistance to sintering and poisoning of gold clusters during operation. Additional research focused on better understanding the role of gold clusters and nanoparticles in gas-sensing effects is also required. (author)

Synthesis and luminescent properties of PEO/lanthanide oxide nanoparticle hybrid films

Energy Technology Data Exchange (ETDEWEB)

Goubard, F. [LPPI, Universite de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise cedex (France)]. E-mail: fabrice.goubard@u-cergy.fr; Vidal, F. [LPPI, Universite de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise cedex (France); Bazzi, R. [LPCML, Universite Lyon 1, 43 Bd. du 11 Novembre 1918, 69622 Villeurbanne (France); Tillement, O. [LPCML, Universite Lyon 1, 43 Bd. du 11 Novembre 1918, 69622 Villeurbanne (France); Nano-H, 23 rue Royal, 69001 Lyon (France); Chevrot, C. [LPPI, Universite de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise cedex (France); Teyssie, D. [LPPI, Universite de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise cedex (France)

2007-10-15

In this study, we investigate the optical properties of lanthanide oxide nanoparticles dispersed in poly(ethylene oxide) (PEO) network as thermally stable polymeric films. The aim of this work is both to keep a good optical transparency in the visible domain and to obtain luminescent materials after incorporation of nanoparticles. For this purpose, we develop luminescent nanocrystals of oxides containing terbium ion as a doping element in Gd{sub 2}O{sub 3}. These sub-5-nm lanthanide oxides nanoparticles have been prepared by direct oxide precipitation in high-boiling polyalcohol solutions and characterized by luminescence spectroscopy. PEO/lanthanide oxide nanohybrid films are prepared by radical polymerization of poly(ethylene glycol) methacrylate after introduction of lanthanide oxide particles. As a first result; the obtained films present interesting luminescence properties with a very low lanthanide oxide content (up to 0.29 wt%). Furthermore, these films are still transparent and keep their original mechanical properties. Prior to describe the specific applications to optical use, we report here the dynamic mechanical analysis (DMA), X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), and luminescent properties of. nanohybrid films.

Synergistic effect of bolus exposure to zinc oxide nanoparticles on bleomycin-induced secretion of pro-fibrotic cytokines without lasting fibrotic changes in murine lungs.

Science.gov (United States)

Wu, Wenting; Ichihara, Gaku; Hashimoto, Naozumi; Hasegawa, Yoshinori; Hayashi, Yasuhiko; Tada-Oikawa, Saeko; Suzuki, Yuka; Chang, Jie; Kato, Masashi; D'Alessandro-Gabazza, Corina N; Gabazza, Esteban C; Ichihara, Sahoko

2014-12-30

Zinc oxide (ZnO) nanoparticles are widely used in various products, and the safety evaluation of this manufactured material is important. The present study investigated the inflammatory and fibrotic effects of pulmonary exposure to ZnO nanoparticles in a mouse model of pulmonary fibrosis. Pulmonary fibrosis was induced by constant subcutaneous infusion of bleomycin (BLM). Female C57BL/6Jcl mice were divided into BLM-treated and non-treated groups. In each treatment group, 0, 10, 20 or 30 µg of ZnO nanoparticles were delivered into the lungs through pharyngeal aspiration. Bronchoalveolar lavage fluid (BALF) and the lungs were sampled at Day 10 or 14 after administration. Pulmonary exposure by a single bolus of ZnO nanoparticles resulted in severe, but transient inflammatory infiltration and thickening of the alveolar septa in the lungs, along with the increase of total and differential cell counts in BLAF. The BALF level of interleukin (IL)-1β and transforming growth factor (TGF)-β was increased at Day 10 and 14, respectively. At Day 10, the synergistic effect of BLM and ZnO exposure was detected on IL-1β and monocyte chemotactic protein (MCP)-1 in BALF. The present study demonstrated the synergistic effect of pulmonary exposure to ZnO nanoparticles and subcutaneous infusion of BLM on the secretion of pro-fibrotic cytokines in the lungs.

Trends in the Catalytic CO Oxidation Activity of Nanoparticles

DEFF Research Database (Denmark)

Nørskov, Jens Kehlet; Falsig, Hanne; Larsen, Britt Hvolbæk

2008-01-01

Going for gold: Density functional calculations show how gold nanoparticles are more active catalysts for CO oxidation than other metal nanoparticles. The high catalytic activity of nanosized gold clusters at low temperature is found to be related to the ability of low-coordinate metal atoms...

Surface functionalization of dopamine coated iron oxide nanoparticles for various surface functionalities

Energy Technology Data Exchange (ETDEWEB)

Sherwood, Jennifer; Xu, Yaolin; Lovas, Kira [Chemical and Biological Engineering, The University of Alabama, Tuscaloosa , AL 35487 (United States); Qin, Ying [Alabama Innovation and Mentoring of Entrepreneurs, The University of Alabama, Tuscaloosa, AL 35487 (United States); Bao, Yuping, E-mail: ybao@eng.ua.edu [Chemical and Biological Engineering, The University of Alabama, Tuscaloosa , AL 35487 (United States)

2017-04-01

We present effective conjugation of four small molecules (glutathione, cysteine, lysine, and Tris(hydroxymethyl)aminomethane) onto dopamine-coated iron oxide nanoparticles. Conjugation of these molecules could improve the surface functionality of nanoparticles for more neutral surface charge at physiological pH and potentially reduce non-specific adsorption of proteins to nanoparticles surfaces. The success of conjugation was evaluated with dynamic light scattering by measuring the surface charge changes and Fourier transform infrared spectroscopy for surface chemistry analysis. The stability of dopamine-coated nanoparticles and the ability of conjugated nanoparticles to reduce the formation of protein corona were evaluated by measuring the size and charge of the nanoparticles in biological medium. This facile conjugation method opens up possibilities for attaching various surface functionalities onto iron oxide nanoparticle surfaces for biomedical applications.

Surface functionalization of dopamine coated iron oxide nanoparticles for various surface functionalities

International Nuclear Information System (INIS)

Sherwood, Jennifer; Xu, Yaolin; Lovas, Kira; Qin, Ying; Bao, Yuping

2017-01-01

We present effective conjugation of four small molecules (glutathione, cysteine, lysine, and Tris(hydroxymethyl)aminomethane) onto dopamine-coated iron oxide nanoparticles. Conjugation of these molecules could improve the surface functionality of nanoparticles for more neutral surface charge at physiological pH and potentially reduce non-specific adsorption of proteins to nanoparticles surfaces. The success of conjugation was evaluated with dynamic light scattering by measuring the surface charge changes and Fourier transform infrared spectroscopy for surface chemistry analysis. The stability of dopamine-coated nanoparticles and the ability of conjugated nanoparticles to reduce the formation of protein corona were evaluated by measuring the size and charge of the nanoparticles in biological medium. This facile conjugation method opens up possibilities for attaching various surface functionalities onto iron oxide nanoparticle surfaces for biomedical applications.

in vivo EFFECTS OF RARE-EARTH BASED NANOPARTICLES ON OXIDATIVE BALANCE IN RATS

Directory of Open Access Journals (Sweden)

V. K. Klochkov

2016-12-01

Full Text Available The purpose of the research was to find the influence of rare-earth based nanoparticles (CeO2, GdVO2: Eu3+ on the oxidative balance in rats. We analyzed biochemical markers of oxidative stress (lipid peroxidation level, nitric oxide metabolites, sulfhydryl groups content and enzyme activities (superoxide dismutase, catalase in tissues of rats. It has been found that administration of both types of the nanoparticles increased nitric oxide metabolites and products of lipid peroxidation in liver and spleen within 5 days. At injections of GdVO2: Eu3+ lipid peroxidation products, nitric oxide metabolites in serum at 5, 10 and 15 days of the experiment was also increased whereas the level of sulfhydryl groups decreased compared to the intact state and the control. In contrast, under the influence of nanoparticle CeO2 level diene conjugates were not significantly changed and the level of nitric oxide metabolites within 15 day even decreased. During this period, under the influence of both types of nanoparticles the activity of superoxide dismutase was increased, catalase activity was not changed. Oxidative stress coefficient showed the less pronounced CeO2 prooxidant effect (2.04 in comparison to GdVO2: Eu3+ (6.89. However, after-effect of both types of nanoparticles showed complete restoration of oxidative balance values.

CuO reduction induced formation of CuO/Cu2O hybrid oxides

Science.gov (United States)

Yuan, Lu; Yin, Qiyue; Wang, Yiqian; Zhou, Guangwen

2013-12-01

Reduction of CuO nanowires results in the formation of a unique hierarchical hybrid nanostructure, in which the parent oxide phase (CuO) works as the skeleton while the lower oxide (Cu2O) resulting from the reduction reaction forms as partially embedded nanoparticles that decorate the skeleton of the parent oxide. Using in situ transmission electron microscopy observations of the reduction process of CuO nanowires, we demonstrate that the formation of such a hierarchical hybrid oxide structure is induced by topotactic nucleation and growth of Cu2O islands on the parent CuO nanowires.

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.

Human nitric oxide biomarker as potential NO donor in conjunction with superparamagnetic iron oxide @ gold core shell nanoparticles for cancer therapeutics.

Science.gov (United States)

Singh, Nimisha; Patel, Khushbu; Sahoo, Suban K; Kumar, Rajender

2018-03-01

Nitric oxide releasing superparamagnetic (Fe 3 O 4 -Au@NTHP) nanoparticles were synthesized by conjugation of human biomarker of nitric oxide, N-nitrosothioproline with iron oxide-gold (Fe 3 O 4 -Au) core shell nanoparticles. The structure and morphology of the prepared nanoparticles were confirmed by ATR-FTIR, HR-TEM, EDAX, XPS, DLS and VSM measurements. N-nitrosothioproline is a natural molecule and nontoxic to humans. Thus, the core shell nanoparticles prepared were highly biocompatible. The prepared Fe 3 O 4 -Au@NTHP nanoparticles also provided an excellent release of nitric oxide in dark and upon light irradiation for cancer treatment. The amount of NO release was controllable with the wavelength of light and time of irradiation. The developed nanoparticles provided efficient cellular uptake and good cytotoxicity in picomolar range when tested on HeLa cancerous cells. These nanoparticles on account of their controllable NO release can also be used to release small amount of NO for killing cancerous cells without any toxic effect. Furthermore, the magnetic and photochemical properties of these nanoparticles provides dual platform for magneto therapy and phototherapy for cancer treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

In-situ synthesis of magnetic iron-oxide nanoparticle-nanofibre composites using electrospinning

International Nuclear Information System (INIS)

Burke, Luke; Mortimer, Chris J.; Curtis, Daniel J.; Lewis, Aled R.; Williams, Rhodri; Hawkins, Karl; Maffeis, Thierry G.G.; Wright, Chris J.

2017-01-01

We demonstrate a facile, one-step process to form polymer scaffolds composed of magnetic iron oxide nanoparticles (MNPs) contained within electrospun nano- and micro-fibres of two biocompatible polymers, Poly(ethylene oxide) (PEO) and Poly(vinyl pyrrolidone) (PVP). This was achieved with both needle and free-surface electrospinning systems demonstrating the scalability of the composite fibre manufacture; a 228 fold increase in fibre fabrication was observed for the free-surface system. In all cases the nanoparticle-nanofibre composite scaffolds displayed morphological properties as good as or better than those previously described and fabricated using complex multi-stage techniques. Fibres produced had an average diameter (Needle-spun: 125 ± 18 nm (PEO) and 1.58 ± 0.28 μm (PVP); Free-surface electrospun: 155 ± 31 nm (PEO)) similar to that reported previously, were smooth with no bead defects. Nanoparticle-nanofibre composites were characterised using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS) (Nanoparticle average diameter ranging from 8 ± 3 nm to 27 ± 5 nm), XRD (Phase of iron oxide nanoparticles identified as magnetite) and nuclear magnetic resonance relaxation measurements (NMR) (T1/T2: 32.44 for PEO fibres containing MNPs) were used to verify the magnetic behaviour of MNPs. This study represents a significant step forward for production rates of magnetic nanoparticle-nanofibre composite scaffolds by the electrospinning technique. - Graphical abstract: We present a novel facile, one-step process for the in-situ synthesis of magnetic iron oxide nanoparticle-nanofibre composites using both needle and free-surface electrospinning. This is a significant step forward for production rates of magnetic nanoparticle-nanofibre scaffolds both in terms of fibre and nanoparticle production. - Highlights: • We present a novel process for the in-situ synthesis of magnetic iron oxide nanoparticle

In-situ synthesis of magnetic iron-oxide nanoparticle-nanofibre composites using electrospinning

Energy Technology Data Exchange (ETDEWEB)

Burke, Luke; Mortimer, Chris J. [Biomaterials, Biofouling and Biofilms Engineering Laboratory (B3EL), Systems and Process Engineering Centre, College of Engineering, Swansea University, Fabian Way, Swansea SA1 8EN (United Kingdom); Systems and Process Engineering Centre, College of Engineering, Swansea University, Fabian Way, Swansea SA1 8EN (United Kingdom); Curtis, Daniel J.; Lewis, Aled R.; Williams, Rhodri [Systems and Process Engineering Centre, College of Engineering, Swansea University, Fabian Way, Swansea SA1 8EN (United Kingdom); Hawkins, Karl [Centre for NanoHealth (CNH), Swansea University, Singleton Park, Swansea SA2 8PP (United Kingdom); Maffeis, Thierry G.G. [Systems and Process Engineering Centre, College of Engineering, Swansea University, Fabian Way, Swansea SA1 8EN (United Kingdom); Wright, Chris J., E-mail: c.wright@swansea.ac.uk [Biomaterials, Biofouling and Biofilms Engineering Laboratory (B3EL), Systems and Process Engineering Centre, College of Engineering, Swansea University, Fabian Way, Swansea SA1 8EN (United Kingdom); Systems and Process Engineering Centre, College of Engineering, Swansea University, Fabian Way, Swansea SA1 8EN (United Kingdom); Centre for NanoHealth (CNH), Swansea University, Singleton Park, Swansea SA2 8PP (United Kingdom)

2017-01-01

We demonstrate a facile, one-step process to form polymer scaffolds composed of magnetic iron oxide nanoparticles (MNPs) contained within electrospun nano- and micro-fibres of two biocompatible polymers, Poly(ethylene oxide) (PEO) and Poly(vinyl pyrrolidone) (PVP). This was achieved with both needle and free-surface electrospinning systems demonstrating the scalability of the composite fibre manufacture; a 228 fold increase in fibre fabrication was observed for the free-surface system. In all cases the nanoparticle-nanofibre composite scaffolds displayed morphological properties as good as or better than those previously described and fabricated using complex multi-stage techniques. Fibres produced had an average diameter (Needle-spun: 125 ± 18 nm (PEO) and 1.58 ± 0.28 μm (PVP); Free-surface electrospun: 155 ± 31 nm (PEO)) similar to that reported previously, were smooth with no bead defects. Nanoparticle-nanofibre composites were characterised using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS) (Nanoparticle average diameter ranging from 8 ± 3 nm to 27 ± 5 nm), XRD (Phase of iron oxide nanoparticles identified as magnetite) and nuclear magnetic resonance relaxation measurements (NMR) (T1/T2: 32.44 for PEO fibres containing MNPs) were used to verify the magnetic behaviour of MNPs. This study represents a significant step forward for production rates of magnetic nanoparticle-nanofibre composite scaffolds by the electrospinning technique. - Graphical abstract: We present a novel facile, one-step process for the in-situ synthesis of magnetic iron oxide nanoparticle-nanofibre composites using both needle and free-surface electrospinning. This is a significant step forward for production rates of magnetic nanoparticle-nanofibre scaffolds both in terms of fibre and nanoparticle production. - Highlights: • We present a novel process for the in-situ synthesis of magnetic iron oxide nanoparticle

Characterization of Titanium Oxide Nanoparticles Obtained by Hydrolysis Reaction of Ethylene Glycol Solution of Alkoxide

Directory of Open Access Journals (Sweden)

Naofumi Uekawa

2012-01-01

Full Text Available Transparent and stable sols of titanium oxide nanoparticles were obtained by heating a mixture of ethylene glycol solution of titanium tetraisopropoxide (TIP and a NH3 aqueous solution at 368 K for 24 h. The concentration of NH3 aqueous solution affected the structure of the obtained titanium oxide nanoparticles. For NH3 aqueous solution concentrations higher than 0.2 mol/L, a mixture of anatase TiO2 nanoparticles and layered titanic acid nanoparticles was obtained. The obtained sol was very stable without formation of aggregated precipitates and gels. Coordination of ethylene glycol to Ti4+ ions inhibited the rapid hydrolysis reaction and aggregation of the obtained nanoparticles. The obtained titanium oxide nanoparticles had a large specific surface area: larger than 350 m2/g. The obtained titanium oxide nanoparticles showed an enhanced adsorption towards the cationic dye molecules. The selective adsorption corresponded to presence of layered titanic acid on the obtained anatase TiO2 nanoparticles.

Characterization of Titanium Oxide Nanoparticles Obtained by Hydrolysis Reaction of Ethylene Glycol Solution of Alkoxide

International Nuclear Information System (INIS)

Uekawa, N.; Endo, N.; Ishii, K.; Kojima, T.; Kakegawa, K.

2012-01-01

Transparent and stable sols of titanium oxide nanoparticles were obtained by heating a mixture of ethylene glycol solution of titanium tetraisopropoxide (TIP) and a NH 3 aqueous solution at 368 K for 24 h. The concentration of NH 3 aqueous solution affected the structure of the obtained titanium oxide nanoparticles. For NH 3 aqueous solution concentrations higher than 0.2 mol/L, a mixture of anatase TiO 2 nanoparticles and layered titanic acid nanoparticles was obtained. The obtained sol was very stable without formation of aggregated precipitates and gels. Coordination of ethylene glycol to Ti4+ ions inhibited the rapid hydrolysis reaction and aggregation of the obtained nanoparticles. The obtained titanium oxide nanoparticles had a large specific surface area: larger than 350 m2/g. The obtained titanium oxide nanoparticles showed an enhanced adsorption towards the cationic dye molecules. The selective adsorption corresponded to presence of layered titanic acid on the obtained anatase TiO 2 nanoparticles.

Antibacterial activity of magnetic iron oxide nanoparticles synthesized by laser ablation in liquid

International Nuclear Information System (INIS)

Ismail, Raid A.; Sulaiman, Ghassan M.; Abdulrahman, Safa A.; Marzoog, Thorria R.

2015-01-01

In this study, (50–110 nm) magnetic iron oxide (α-Fe 2 O 3 ) nanoparticles were synthesized by pulsed laser ablation of iron target in dimethylformamide (DMF) and sodium dodecyl sulfate (SDS) solutions. The structural properties of the synthesized nanoparticles were investigated by using Fourier Transform Infrared (FT-IR) spectroscopy, UV–VIS absorption, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). The effect of laser fluence on the characteristics of these nanoparticles was studied. Antibacterial activities of iron oxide nanoparticles were tested against Gram-positive; Staphylococcus aureus and Gram-negative; Escherichia coli, Pseudomonas aeruginosa and Serratia marcescens. The results showed a noteworthy inhibition on both bacterial strains. The preparation conditions were found to affect significantly the antibacterial activity of these nanoparticles. The synthesized magnetic nanoparticles were used to capture rapidly S. aureus bacteria under the magnetic field effect. - Highlights: • Synthesis magnetic iron oxide nanoparticles by pulsed laser ablation • Antibacterial activity against Gram-positive and Gram-negative bacteria • Captured magnetic nanoparticles by S. aureus bacteria under effect of magnetic field

Antibacterial activity of magnetic iron oxide nanoparticles synthesized by laser ablation in liquid

Energy Technology Data Exchange (ETDEWEB)

Ismail, Raid A., E-mail: raidismail@yahoo.com [Laser Physics Division, Applied Science Department, University of Technology, Baghdad (Iraq); Sulaiman, Ghassan M. [Biotechnology Division, Applied Science Department, University of Technology, Baghdad (Iraq); Abdulrahman, Safa A. [Laser Physics Division, Applied Science Department, University of Technology, Baghdad (Iraq); Marzoog, Thorria R. [Biotechnology Division, Applied Science Department, University of Technology, Baghdad (Iraq)

2015-08-01

In this study, (50–110 nm) magnetic iron oxide (α-Fe{sub 2}O{sub 3}) nanoparticles were synthesized by pulsed laser ablation of iron target in dimethylformamide (DMF) and sodium dodecyl sulfate (SDS) solutions. The structural properties of the synthesized nanoparticles were investigated by using Fourier Transform Infrared (FT-IR) spectroscopy, UV–VIS absorption, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). The effect of laser fluence on the characteristics of these nanoparticles was studied. Antibacterial activities of iron oxide nanoparticles were tested against Gram-positive; Staphylococcus aureus and Gram-negative; Escherichia coli, Pseudomonas aeruginosa and Serratia marcescens. The results showed a noteworthy inhibition on both bacterial strains. The preparation conditions were found to affect significantly the antibacterial activity of these nanoparticles. The synthesized magnetic nanoparticles were used to capture rapidly S. aureus bacteria under the magnetic field effect. - Highlights: • Synthesis magnetic iron oxide nanoparticles by pulsed laser ablation • Antibacterial activity against Gram-positive and Gram-negative bacteria • Captured magnetic nanoparticles by S. aureus bacteria under effect of magnetic field.

Improvement of the oxidation stability of cobalt nanoparticles

Directory of Open Access Journals (Sweden)

Celin Dobbrow

2012-01-01

Full Text Available In order to enhance the resistance of cobalt nanoparticles to oxidation in air, the impact of different stabilization strategies on the isothermal oxidation of particle dispersions and powders was kinetically investigated and compared to as-prepared particle preparations. A post-synthesis treatment with different alcohols was employed, and we also investigate the influence of two different polymer shells on the oxidation process. We found a parabolic decrease of the magnetization for all particle charges, indicating that the process is dominated by a diffusion of oxygen to the cobalt core and a radial growth of the oxide layer from the particle surface to the core. A significant deceleration of the oxidation process was observed for all alcohol-passivated particle preparations, and this resulted finally in a stagnation effect. The stabilizing effect increases in the sequence Co@OA/MeOH < Co@OA/EtOH < Co@OA/iPrOH. For polymer-coated particle preparations Co@PCL and Co@PS, the deceleration was even more pronounced. The results demonstrate that cobalt nanoparticles can effectively be protected against oxidation in order to improve their mid- to longterm stability.

Effect of charged deep states in hydrogenated amorphous silicon on the behavior of iron oxides nanoparticles deposited on its surface

International Nuclear Information System (INIS)

Gmucova, Katarina; Weis, Martin; Nadazdy, Vojtech; Capek, Ignac; Satka, Alexander; Chitu, Livia; Cirak, Julius; Majkova, Eva

2008-01-01

Langmuir-Blodgett technique has been used for the deposition of ordered two-dimensional arrays of iron oxides (Fe 3 O 4 /Fe 2 O 3 ) nanoparticles onto the photovoltaic hydrogenated amorphous silicon (a-Si:H) thin film. Electric field at the a-Si:H/iron oxides nanoparticles interface was directly in the electrochemical cell modified by light soaking and bias voltage (negative or positive) pretreatment resulting in the change of the dominant type of charged deep states in the a-Si:H layer. Induced reversible changes in the nanoparticle redox behavior have been observed. We suggest two possible explanations of the data obtained, both of them are needed to describe measured electrochemical signals. The first one consists in the electrocatalytical effect caused by the defect states (negatively or positively charged) in the a-Si:H layer. The second one consists in the possibility to manipulate the nanoparticle cores in the prepared structure immersed in aqueous solution via the laser irradiation under specific bias voltage. In this case, the nanoparticle cores are assumed to be covered with surface clusters of heterovalent complexes created onto the surface regions with prevailing ferrous or ferric valency. Immersed in the high viscosity surrounding composed of the wet organic nanoparticle envelope these cores are able to perform a field-assisted pivotal motion. The local electric field induced by the deep states in the a-Si:H layer stabilizes their 'orientation ordering' in an energetically favourable position

Examining mechanism of toxicity of copper oxide nanoparticles to Saccharomyces cerevisiae and Caenorhabditis elegans

Science.gov (United States)

Mashock, Michael J.

Copper oxide nanoparticles (CuO NPs) are an up and coming technology increasingly being used in industrial and consumer applications and thus may pose risk to humans and the environment. In the present study, the toxic effects of CuO NPs were studied with two model organisms Saccharomyces cerevisiae and Caenorhabditis elegans. The role of released Cu ions during dissolution of CuO NPs in growth media were studied with freshly suspended, aged NPs, and the released Cu 2+ fraction. Exposures to the different Cu treatments showed significant inhibition of S. cerevisiae cellular metabolic activity. Inhibition from the NPs was inversely proportional to size and was not fully explained by the released Cu ions. S. cerevisiae cultures grown under respiring conditions demonstrated greater metabolic sensitivity when exposed to CuO NPs compared to cultures undergoing fermentation. The cellular response to both CuO NPs and released Cu ions on gene expression was analyzed via microarray analysis after an acute exposure. It was observed that both copper exposures resulted in an increase in carbohydrate storage, a decrease in protein production, protein misfolding, increased membrane permeability, and cell cycle arrest. Cells exposed to NPs up-regulated genes related to oxidative phosphorylation but also may be inducing cell cycle arrest by a different mechanism than that observed with released Cu ions. The effect of CuO NPs on C. elegans was examined by using several toxicological endpoints. The CuO NPs displayed a more inhibitory effect, compared to copper sulfate, on nematode reproduction, feeding, and development. We investigated the effects of copper oxide nanoparticles and copper sulfate on neuronal health, a known tissue vulnerable to heavy metal toxicity. In transgenic C. eleganswith neurons expressing a green fluorescent protein reporter, neuronal degeneration was observed in up to 10% of the population after copper oxide nanoparticle exposure. Additionally, nematode

Effects of concentration of Ag nanoparticles on surface structure and in vitro biological responses of oxide layer on pure titanium via plasma electrolytic oxidation

Energy Technology Data Exchange (ETDEWEB)

Shin, Ki Ryong; Kim, Yeon Sung; Kim, Gye Won [Department of Materials Science and Engineering, Hanyang University, Ansan 425-791 (Korea, Republic of); Yang, Hae Woong [School of Materials Science and Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Ko, Young Gun, E-mail: younggun@ynu.ac.kr [School of Materials Science and Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Shin, Dong Hyuk, E-mail: dhshin@hanyang.ac.kr [Department of Materials Science and Engineering, Hanyang University, Ansan 425-791 (Korea, Republic of)

2015-08-30

Highlights: • Ag nanoparticles were embedded into the oxide surface without any compositional changes. • Oxide layer from the electrolyte with 0.1 g/l Ag nanoparticles could disinfect all bacteria. • With increasing Ag nanoparticles, bone-forming ability and cell proliferation rate decrease. - Abstract: This study was to investigate how Ag nanoparticles with various concentrations affect the surface structure and in vitro biological properties of oxide layers on the pure titanium produced by a plasma electrolytic oxidation (PEO) process. For this aim, PEO processes were carried out at an AC current density of 100 mA/cm{sup 2} for 300 s in potassium pyrophosphate (K{sub 4}P{sub 2}O{sub 7}) electrolytes containing 0, 0.1, 0.3 and 0.5 g/l Ag nanoparticles. Structural investigations using scanning electron microscopy evidenced that the oxide layers showed the successful incorporation of Ag nanoparticles, and the topographical deformation of the porous surface was found when the concentration of Ag nanoparticles was more than 0.1 g/l. Based on the anti-bacterial activity of all oxide layers, the Ag nanoparticles uniformly spread were of considerable importance in triggering the disinfection of E. coli bacteria. The bone forming abilities and cell (MC3T3-E1) proliferation rates of oxide layers produced in electrolytes containing 0 and 0.1 g/l Ag nanoparticles were higher than those containing 0.3 and 0.5 g/l Ag nanoparticles. Consequently, the oxide layer on pure titanium via PEO process in the electrolyte with 0.1 g/l Ag nanoparticles exhibited better the bioactivity accompanying the anti-bacterial activity.

Facile preparation of superhydrophobic surfaces based on metal oxide nanoparticles

Science.gov (United States)

Bao, Xue-Mei; Cui, Jin-Feng; Sun, Han-Xue; Liang, Wei-Dong; Zhu, Zhao-Qi; An, Jin; Yang, Bao-Ping; La, Pei-Qing; Li, An

2014-06-01

A novel method for fabrication of superhydrophobic surfaces was developed by facile coating various metal oxide nanoparticles, including ZnO, Al2O3 and Fe3O4, on various substrates followed by treatment with polydimethylsiloxane (PDMS) via chemical vapor deposition (CVD) method. Using ZnO nanoparticles as a model, the changes in the surface chemical composition and crystalline structures of the metal oxide nanoparticles by PDMS treatment were investigated by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The results show that the combination of the improved surface roughness generated from of the nanoparticles aggregation with the low surface-energy of silicon-coating originated from the thermal pyrolysis of PDMS would be responsible for the surface superhydrophobicity. By a simple dip-coating method, we show that the metal oxide nanoparticles can be easily coated onto the surfaces of various textural and dimensional substrates, including glass slide, paper, fabric or sponge, for preparation of superhydrophobic surfaces for different purpose. The present strategy may provide an inexpensive and new route to surperhydrophobic surfaces, which would be of technological significance for various practical applications especially for separation of oils or organic contaminates from water.

Facile preparation of superhydrophobic surfaces based on metal oxide nanoparticles

International Nuclear Information System (INIS)

Bao, Xue-Mei; Cui, Jin-Feng; Sun, Han-Xue; Liang, Wei-Dong; Zhu, Zhao-Qi; An, Jin; Yang, Bao-Ping; La, Pei-Qing; Li, An

2014-01-01

A novel method for fabrication of superhydrophobic surfaces was developed by facile coating various metal oxide nanoparticles, including ZnO, Al 2 O 3 and Fe 3 O 4 , on various substrates followed by treatment with polydimethylsiloxane (PDMS) via chemical vapor deposition (CVD) method. Using ZnO nanoparticles as a model, the changes in the surface chemical composition and crystalline structures of the metal oxide nanoparticles by PDMS treatment were investigated by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The results show that the combination of the improved surface roughness generated from of the nanoparticles aggregation with the low surface-energy of silicon-coating originated from the thermal pyrolysis of PDMS would be responsible for the surface superhydrophobicity. By a simple dip-coating method, we show that the metal oxide nanoparticles can be easily coated onto the surfaces of various textural and dimensional substrates, including glass slide, paper, fabric or sponge, for preparation of superhydrophobic surfaces for different purpose. The present strategy may provide an inexpensive and new route to surperhydrophobic surfaces, which would be of technological significance for various practical applications especially for separation of oils or organic contaminates from water.

Facile preparation of superhydrophobic surfaces based on metal oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Bao, Xue-Mei; Cui, Jin-Feng; Sun, Han-Xue; Liang, Wei-Dong; Zhu, Zhao-Qi; An, Jin; Yang, Bao-Ping; La, Pei-Qing; Li, An, E-mail: lian2010@lut.cn

2014-06-01

A novel method for fabrication of superhydrophobic surfaces was developed by facile coating various metal oxide nanoparticles, including ZnO, Al{sub 2}O{sub 3} and Fe{sub 3}O{sub 4}, on various substrates followed by treatment with polydimethylsiloxane (PDMS) via chemical vapor deposition (CVD) method. Using ZnO nanoparticles as a model, the changes in the surface chemical composition and crystalline structures of the metal oxide nanoparticles by PDMS treatment were investigated by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The results show that the combination of the improved surface roughness generated from of the nanoparticles aggregation with the low surface-energy of silicon-coating originated from the thermal pyrolysis of PDMS would be responsible for the surface superhydrophobicity. By a simple dip-coating method, we show that the metal oxide nanoparticles can be easily coated onto the surfaces of various textural and dimensional substrates, including glass slide, paper, fabric or sponge, for preparation of superhydrophobic surfaces for different purpose. The present strategy may provide an inexpensive and new route to surperhydrophobic surfaces, which would be of technological significance for various practical applications especially for separation of oils or organic contaminates from water.

Electrodeposition of silver nanoparticle arrays on transparent conductive oxides

International Nuclear Information System (INIS)

Zhang, Dezhong; Tang, Yang; Jiang, Fuguo; Han, Zhihua; Chen, Jie

2016-01-01

Highlights: • The sliver nanoparticles' size and the distance between nanoparticles are tunable. - Abstract: In this paper, we present a facile method for the preparation of silver nanoparticles on aluminum-doped zinc oxide (AZO) via electrodeposition techniques at room temperature. The morphology and structure of silver nanoparticles are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), respectively. Due to localized surface plasmon resonances, as-prepared silver nanoparticles on AZO glass exhibited different reflectivity in contrast with bare AZO glass. The weighted reflection of AZO substrate increased from 10.2% to 12.8%. The high reflection property of silver nanoparticle arrays on AZO substrate might be applicable for thin film solar cells and other optoelectronics applications.

Electrodeposition of silver nanoparticle arrays on transparent conductive oxides

Energy Technology Data Exchange (ETDEWEB)

Zhang, Dezhong; Tang, Yang, E-mail: tangyang@nicenergy.com; Jiang, Fuguo; Han, Zhihua; Chen, Jie

2016-04-30

Highlights: • The sliver nanoparticles' size and the distance between nanoparticles are tunable. - Abstract: In this paper, we present a facile method for the preparation of silver nanoparticles on aluminum-doped zinc oxide (AZO) via electrodeposition techniques at room temperature. The morphology and structure of silver nanoparticles are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), respectively. Due to localized surface plasmon resonances, as-prepared silver nanoparticles on AZO glass exhibited different reflectivity in contrast with bare AZO glass. The weighted reflection of AZO substrate increased from 10.2% to 12.8%. The high reflection property of silver nanoparticle arrays on AZO substrate might be applicable for thin film solar cells and other optoelectronics applications.

Size distribution of magnetic iron oxide nanoparticles using Warren-Averbach XRD analysis

Science.gov (United States)

Mahadevan, S.; Behera, S. P.; Gnanaprakash, G.; Jayakumar, T.; Philip, J.; Rao, B. P. C.

2012-07-01

We use the Fourier transform based Warren-Averbach (WA) analysis to separate the contributions of X-ray diffraction (XRD) profile broadening due to crystallite size and microstrain for magnetic iron oxide nanoparticles. The profile shape of the column length distribution, obtained from WA analysis, is used to analyze the shape of the magnetic iron oxide nanoparticles. From the column length distribution, the crystallite size and its distribution are estimated for these nanoparticles which are compared with size distribution obtained from dynamic light scattering measurements. The crystallite size and size distribution of crystallites obtained from WA analysis are explained based on the experimental parameters employed in preparation of these magnetic iron oxide nanoparticles. The variation of volume weighted diameter (Dv, from WA analysis) with saturation magnetization (Ms) fits well to a core shell model wherein it is known that Ms=Mbulk(1-6g/Dv) with Mbulk as bulk magnetization of iron oxide and g as magnetic shell disorder thickness.

Iron oxide nanoparticles stabilized inside highly ordered ...

Indian Academy of Sciences (India)

CdS nanoparticles prepared in reverse micellar system was incorporated into ... The molar ratio of various constituents of the hydrothermal gel was ... other synthesis techniques for the preparation of iron oxide nanocomposites using.

Effects of amorphous silica coating on cerium oxide nanoparticles induced pulmonary responses

Energy Technology Data Exchange (ETDEWEB)

Ma, Jane, E-mail: jym1@cdc.gov [Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV (United States); Mercer, Robert R.; Barger, Mark; Schwegler-Berry, Diane [Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV (United States); Cohen, Joel M.; Demokritou, Philip [Harvard TH Chan School of Public Health, Harvard University, Boston, MA (United States); Castranova, Vincent [School of Pharmacy, West Virginia University, Morgantown, WV (United States)

2015-10-01

Recently cerium compounds have been used in a variety of consumer products, including diesel fuel additives, to increase fuel combustion efficiency and decrease diesel soot emissions. However, cerium oxide (CeO{sub 2}) nanoparticles have been detected in the exhaust, which raises a health concern. Previous studies have shown that exposure of rats to nanoscale CeO{sub 2} by intratracheal instillation (IT) induces sustained pulmonary inflammation and fibrosis. In the present study, male Sprague–Dawley rats were exposed to CeO{sub 2} or CeO{sub 2} coated with a nano layer of amorphous SiO{sub 2} (aSiO{sub 2}/CeO{sub 2}) by a single IT and sacrificed at various times post-exposure to assess potential protective effects of the aSiO{sub 2} coating. The first acellular bronchoalveolar lavage (BAL) fluid and BAL cells were collected and analyzed from all exposed animals. At the low dose (0.15 mg/kg), CeO{sub 2} but not aSiO{sub 2}/CeO{sub 2} exposure induced inflammation. However, at the higher doses, both particles induced a dose-related inflammation, cytotoxicity, inflammatory cytokines, matrix metalloproteinase (MMP)-9, and tissue inhibitor of MMP at 1 day post-exposure. Morphological analysis of lung showed an increased inflammation, surfactant and collagen fibers after CeO{sub 2} (high dose at 3.5 mg/kg) treatment at 28 days post-exposure. aSiO{sub 2} coating significantly reduced CeO{sub 2}-induced inflammatory responses in the airspace and appeared to attenuate phospholipidosis and fibrosis. Energy dispersive X-ray spectroscopy analysis showed Ce and phosphorous (P) in all particle-exposed lungs, whereas Si was only detected in aSiO{sub 2}/CeO{sub 2}-exposed lungs up to 3 days after exposure, suggesting that aSiO{sub 2} dissolved off the CeO{sub 2} core, and some of the CeO{sub 2} was transformed to CePO{sub 4} with time. These results demonstrate that aSiO{sub 2} coating reduce CeO{sub 2}-induced inflammation, phospholipidosis and fibrosis. - Highlights: • Both

Aqueous starch as a stabilizer in zinc oxide nanoparticle synthesis via laser ablation

Energy Technology Data Exchange (ETDEWEB)

Zamiri, Reza; Zakaria, Azmi [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Ahangar, Hossein Abbastabar [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Darroudi, Majid [Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Zak, Ali Khorsand [Low Dimensional Material Research Center, Department of Physics, University of Malaya, Kuala Lumpur 50603 (Malaysia); Drummen, Gregor P.C., E-mail: gpcdrummen@bionano-solutions.de [Bionanoscience and Bio-Imaging Program, Cellular Stress and Ageing Program, Bio and Nano-Solutions, D-40472 Duesseldorf (Germany)

2012-03-05

Highlights: Black-Right-Pointing-Pointer Zinc oxide nanoparticles were synthesized via LASiS in aqueous starch solution. Black-Right-Pointing-Pointer Nanoparticles of {+-}15 nm are produced with a narrow size distribution. Black-Right-Pointing-Pointer Starch can be used as a template to control nanoparticle size. Black-Right-Pointing-Pointer Starch stabilizes zinc oxide nanoparticles in solution through steric hindrance. - Abstract: Zinc oxide is a semiconductor with exceptional thermal, luminescent and electrical properties, even compared with other semiconducting nanoparticles. Its potential for advanced applications in lasers and light emitting diodes, as bio-imaging agent, in biosensors and as drug delivery vehicles, in ointments, coatings and pigments has pulled zinc oxide into the focus of various scientific and engineering research fields. Recently we started investigating if nanoparticle synthesis via laser ablation in the presence of natural stabilizers allows control over size and shape and constitutes a useful, uncomplicated alternative over conventional synthesis methods. In the current paper, we determined the ability of natural starch to act as a size controller and stabilizer in the preparation of zinc oxide nanoparticles via ablation of a ZnO plate in a starch solution with a nanosecond Q-Switched Nd:YAG pulsed laser at its original wavelength ({lambda} = 1064 nm). Our results show that the particle diameter decreases with increasing laser irradiation time to a mean nanoparticle size of approximately 15 nm with a narrow size distribution. Furthermore, the obtained particle size in starch solution is considerably smaller compared with analogous ZnO nanoparticle synthesis in distilled water. The synthesized and capped nanoparticles retained their photoluminescent properties, but showed blue emission rather than the often reported green luminescence. Evaluation of old preparations compared with freshly made samples showed no agglomeration or

Aqueous starch as a stabilizer in zinc oxide nanoparticle synthesis via laser ablation

International Nuclear Information System (INIS)

Zamiri, Reza; Zakaria, Azmi; Ahangar, Hossein Abbastabar; Darroudi, Majid; Zak, Ali Khorsand; Drummen, Gregor P.C.

2012-01-01

Highlights: ► Zinc oxide nanoparticles were synthesized via LASiS in aqueous starch solution. ► Nanoparticles of ±15 nm are produced with a narrow size distribution. ► Starch can be used as a template to control nanoparticle size. ► Starch stabilizes zinc oxide nanoparticles in solution through steric hindrance. - Abstract: Zinc oxide is a semiconductor with exceptional thermal, luminescent and electrical properties, even compared with other semiconducting nanoparticles. Its potential for advanced applications in lasers and light emitting diodes, as bio-imaging agent, in biosensors and as drug delivery vehicles, in ointments, coatings and pigments has pulled zinc oxide into the focus of various scientific and engineering research fields. Recently we started investigating if nanoparticle synthesis via laser ablation in the presence of natural stabilizers allows control over size and shape and constitutes a useful, uncomplicated alternative over conventional synthesis methods. In the current paper, we determined the ability of natural starch to act as a size controller and stabilizer in the preparation of zinc oxide nanoparticles via ablation of a ZnO plate in a starch solution with a nanosecond Q-Switched Nd:YAG pulsed laser at its original wavelength (λ = 1064 nm). Our results show that the particle diameter decreases with increasing laser irradiation time to a mean nanoparticle size of approximately 15 nm with a narrow size distribution. Furthermore, the obtained particle size in starch solution is considerably smaller compared with analogous ZnO nanoparticle synthesis in distilled water. The synthesized and capped nanoparticles retained their photoluminescent properties, but showed blue emission rather than the often reported green luminescence. Evaluation of old preparations compared with freshly made samples showed no agglomeration or flocculation, which was reflected in no significant change in the ZnO nanoparticle size and size distribution. Overall

Impact of metal and metal oxide nanoparticles on plant: A critical review

Science.gov (United States)

Rastogi, Anshu; Zivcak, Marek; Sytar, Oksana; Kalaji, Hazem M.; He, Xiaolan; Mbarki, Sonia; Brestic, Marian

2017-10-01

An increasing need of nanotechnology in various industries may cause a huge environment dispersion of nanoparticles in coming years. A concern about nanoparticles interaction with flora and fauna is raised due to a growing load of it in the environment. In recent years, several investigators have shown impact of nanoparticles on plant growth and its accumulation in food source. This review examines the research performed in the last decade to show how metal and metal oxide nanoparticles are influencing the plant metabolisms. We addressed here, the impact of nanoparticle on plant in relation to its size, concentration, and exposure methodology. Based on the available reports, we proposed oxidative burst as a general mechanism through which the toxic effects of nanoparticles are spread in plants. This review summarises the current understanding and the future possibilities of plant-nanoparticle research.

Magnetic properties of Fe-oxide and (Fe, Co) oxide nanoparticles synthesized in polystyrene resin matrix

Science.gov (United States)

Rodak, D.; Kroll, E.; Tsoi, G. M.; Vaishnava, P. P.; Naik, R.; Wenger, L. E.; Suryanarayanan, R.; Naik, V. M.; Boolchand, P.

2003-03-01

Magnetic nanoparticles have potential applications ranging from drug delivery and imaging in the medical field to sensing and memory storage in technology. The preparation, structure, and physical properties of iron oxide-based nanoparticles synthesized by ion exchange in a polystyrene resin matrix have been investigated. Employing a synthesis method developed originally by Ziolo, et. al^1, nanoparticles were prepared in a sulfonated divinyl benzene polystyrene resin matrix using various aqueous solutions of (1) FeCl_2, (2) FeCl_3, (3) FeCl2 : 2FeCl3 , (4) 9FeCl2 : CoCl_2, and (5) 4FeCl2 : CoCl_2. Powder x-ray diffraction measurements were used to identify the phases present while transmission electron microscopy was used for particle size distribution determinations. SQUID magnetization measurements (field-cooled and zero-field-cooled) and Fe^57 Mössbauer effect measurements indicate the presence of ferromagnetic iron oxide phases and a superparamagnetic behavior with blocking temperatures (T_B) varying from 50 K to room temperature. Nanoparticles synthesized using a stoichiometric mixture of FeCl2 and FeCl3 exhibit the lowest TB and smallest particle size distribution. The Mössbauer effect measurements have also been used to identify the iron oxides phases present and their relative amounts in the nanoparticles ^1R.F. Ziolo, et al., Science 207, 219 (1992). *Permanent address: Kettering University, Flint, MI 48504

Prophylactic Treatment with Cerium Oxide Nanoparticles Attenuate Hepatic Ischemia Reperfusion Injury in Sprague Dawley Rats

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Nandini D.P.K. Manne

2017-07-01

Full Text Available Background: Hepatic ischemia reperfusion is one the main causes for graft failure following transplantation. Although, the molecular events that lead to hepatic failure following ischemia reperfusion (IR are diverse and complex, previous studies have shown that excessive formation of reactive oxygen species (ROS are responsible for hepatic IR injury. Cerium oxide (CeO2 nanoparticles have been previously shown to act as an anti-oxidant and anti-inflammatory agent. Here, we evaluated the protective effects of CeO2 nanoparticles on hepatic ischemia reperfusion injury. Methods: Male Sprague Dawley rats were randomly assigned to one of the four groups: Control, CeO2 nanoparticle only, hepatic ischemia reperfusion (IR group and hepatic ischemia reperfusion (IR plus CeO2 nanoparticle group (IR+ CeO2. Partial warm hepatic ischemia was induced in left lateral and median lobes for 1h, followed by 6h of reperfusion. Animals were sacrificed after 6h of reperfusion and blood and tissue samples were collected and processed for various biochemical experiments. Results: Prophylactic treatment with CeO2 nanoparticles (0.5mg/kg i.v (IR+CeO2 group 1 hour prior to hepatic ischemia and subsequent reperfusion injury lead to a decrease in serum levels of alanine aminotransaminase and lactate dehydrogenase at 6 hours after reperfusion. These changes were accompanied by significant decrease in hepatocyte necrosis along with reduction in several serum inflammatory markers such as macrophage derived chemokine, macrophage inflammatory protein-2, KC/GRO, myoglobin and plasminogen activator inhibitor-1. However, immunoblotting demonstrated no significant changes in the levels of apoptosis related protein markers such as bax, bcl2 and caspase 3 in IR and IR+ CeO2 groups at 6 hours suggesting necrosis as the main pathway for hepatocyte death. Conclusion: Taken together, these data suggest that CeO2 nanoparticles attenuate IR induced cell death and can be used as a prophylactic

Extracellular synthesis of zinc oxide nanoparticle using seaweeds of gulf of Mannar, India

Science.gov (United States)

2013-01-01

Background The biosynthesis of metal nanoparticles by marine resources is thought to be clean, nontoxic, and environmentally acceptable “green procedures”. Marine ecosystems are very important for the overall health of both marine and terrestrial environments. The use of natural sources like Marine biological resources essential for nanotechnology. Seaweeds constitute one of the commercially important marine living renewable resources. Seaweeds such as green Caulerpa peltata, red Hypnea Valencia and brown Sargassum myriocystum were used for synthesis of Zinc oxide nanoparticles. Result The preliminary screening of physico-chemical parameters such as concentration of metals, concentration of seaweed extract, temperature, pH and reaction time revealed that one seaweed S. myriocystum were able to synthesize zinc oxide nanoparticles. It was confirmed through the, initial colour change of the reaction mixture and UV visible spectrophotometer. The extracellular biosynthesized clear zinc oxide nanoparticles size 36 nm through characterization technique such as DLS, AFM, SEM –EDX, TEM, XRD and FTIR. The biosynthesized ZnO nanoparticles are effective antibacterial agents against Gram-positive than the Gram-negative bacteria. Conclusion Based on the FTIR results, fucoidan water soluble pigments present in S. myriocystum leaf extract is responsible for reduction and stabilization of zinc oxide nanoparticles. by this approach are quite stable and no visible changes were observed even after 6 months. These soluble elements could have acted as both reduction and stabilizing agents preventing the aggregation of nanoparticles in solution, extracellular biological synthesis of zinc oxide nanoparticles of size 36 nm. PMID:24298944

Limonia acidissima L. leaf mediated synthesis of zinc oxide nanoparticles: A potent tool against Mycobacterium tuberculosis.

Science.gov (United States)

Taranath, Tarikere C; Patil, Bheemanagouda N

2016-06-01

The present investigation was undertaken to synthesize zinc oxide nanoparticles using Limonia acidissima L. and to test their efficacy against the growth of Mycobacterium tuberculosis. The formation of zinc oxide nanoparticles was confirmed with UV-visible spectrophotometry. Fourier transform infrared spectroscopy shows the presence of bio-molecules involved in the stabilization of zinc oxide nanoparticles. The shape and size was confirmed with atomic force microscope, X-ray diffraction, and high resolution transmission electron microscope. These nanoparticles were tested for their effect on the growth of M. tuberculosis through the microplate alamar blue assay technique. The UV-visible data reveal that an absorbance peak at 374nm confirms formation of zinc oxide nanoparticles and they are spherical in shape with sizes between 12nm and 53nm. These nanoparticles control the growth of M. tuberculosis at 12.5μg/mL. Phytosynthesis of zinc oxide nanoparticles is a green, eco-friendly technology because it is inexpensive and pollution free. In the present investigation, based on our results we conclude that the aqueous extract of leaves of L. acidissima can be used for the synthesis of zinc oxide nanoparticles. These nanoparticles control the growth of M. tuberculosis and this was confirmed with the microplate alamar blue method. The potential of biogenic zinc oxide nanoparticles may be harnessed as a novel medicine ingredient to combat tuberculosis disease. Copyright © 2016 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Highly Sensitive DNA Sensor Based on Upconversion Nanoparticles and Graphene Oxide.

Science.gov (United States)

Alonso-Cristobal, P; Vilela, P; El-Sagheer, A; Lopez-Cabarcos, E; Brown, T; Muskens, O L; Rubio-Retama, J; Kanaras, A G

2015-06-17

In this work we demonstrate a DNA biosensor based on fluorescence resonance energy transfer (FRET) between NaYF4:Yb,Er nanoparticles and graphene oxide (GO). Monodisperse NaYF4:Yb,Er nanoparticles with a mean diameter of 29.1 ± 2.2 nm were synthesized and coated with a SiO2 shell of 11 nm, which allowed the attachment of single strands of DNA. When these DNA-functionalized NaYF4:Yb,Er@SiO2 nanoparticles were in the proximity of the GO surface, the π-π stacking interaction between the nucleobases of the DNA and the sp(2) carbons of the GO induced a FRET fluorescence quenching due to the overlap of the fluorescence emission of the NaYF4:Yb,Er@SiO2 and the absorption spectrum of GO. By contrast, in the presence of the complementary DNA strands, the hybridization leads to double-stranded DNA that does not interact with the GO surface, and thus the NaYF4:Yb,Er@SiO2 nanoparticles remain unquenched and fluorescent. The high sensitivity and specificity of this sensor introduces a new method for the detection of DNA with a detection limit of 5 pM.

Oxidation of Bioethanol using Zeolite-Encapsulated Gold Nanoparticles

DEFF Research Database (Denmark)

Mielby, Jerrik Jørgen; Abildstrøm, Jacob Oskar; Wang, Feng

2014-01-01

With the ongoing developments in biomass conversion, the oxidation of bioethanol to acetaldehyde may become a favorable and green alternative to the preparation from ethylene. Here, a simple and effective method to encapsulate gold nanoparticles in zeolite silicalite-1 is reported and their high...... zeolite crystals comprise a broad range of mesopores and contain up to several hundred gold nanoparticles with a diameter of 2-3nm that are distributed inside the zeolites rather than on the outer surface. The encapsulated nanoparticles have good stability and result in 50% conversion of ethanol with 98...

Oxidation of Bioethanol using Zeolite-Encapsulated Gold Nanoparticles

DEFF Research Database (Denmark)

Mielby, Jerrik Jørgen; Abildstrøm, Jacob Oskar; Wang, Feng

2014-01-01

With the ongoing developments in biomass conversion, the oxidation of bioethanol to acetaldehyde may become a favorable and green alternative to the preparation from ethylene. Here, a simple and effective method to encapsulate gold nanoparticles in zeolite silicalite‐1 is reported and their high...... zeolite crystals comprise a broad range of mesopores and contain up to several hundred gold nanoparticles with a diameter of 2–3 nm that are distributed inside the zeolites rather than on the outer surface. The encapsulated nanoparticles have good stability and result in 50 % conversion of ethanol with 98...

PEGylated bilirubin nanoparticle as an anti-oxidative and anti-inflammatory demulcent in pancreatic islet xenotransplantation.

Science.gov (United States)

Kim, Min Jun; Lee, Yonghyun; Jon, Sangyong; Lee, Dong Yun

2017-07-01

Transplanted islets suffer hypoxic stress, which leads to nonspecific inflammation. This is the major cause of islet graft failure during the early stage of intrahepatic islet transplantation. Although bilirubin has shown potent anti-oxidative and anti-inflammatory functions, its clinical applications have been limited due to its insolubility and short half-life. To overcome this problem, novel amphiphilic bilirubin nanoparticles are designed. Hydrophilic poly(ethylene glycol) (PEG) is conjugated to the hydrophobic bilirubin molecule. Then, the PEG-bilirubin conjugates form nanoparticles via self-assembly, i.e., so-called to BRNPs. BRNPs can protect islet cells not only from chemically induced oxidative stress by scavenging reactive oxygen species molecules, but also from activated macrophages by suppressing cytokine release. Importantly, in vivo experiments demonstrate that BRNP treatment can dramatically and significantly prolong islet graft survival compared to bilirubin treatment. In addition, immunohistochemical analysis shows BRNPs have potent anti-oxidative and anti-inflammatory capabilities. Collectively, novel BRNPs can be a new potent remedy for successful islet transplantation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biocompatible Metal-Oxide Nanoparticles: Nanotechnology Improvement of Conventional Prosthetic Acrylic Resins

Directory of Open Access Journals (Sweden)

Laura S. Acosta-Torres

2011-01-01

Full Text Available Nowadays, most products for dental restoration are produced from acrylic resins based on heat-cured Poly(Methyl MethAcrylate (PMMA. The addition of metal nanoparticles to organic materials is known to increase the surface hydrophobicity and to reduce adherence to biomolecules. This paper describes the use of nanostructured materials, TiO2 and Fe2O3, for simultaneously coloring and/or improving the antimicrobial properties of PMMA resins. Nanoparticles of metal oxides were included during suspension polymerization to produce hybrid metal oxides-alginate-containing PMMA. Metal oxide nanoparticles were characterized by dynamic light scattering, and X-ray diffraction. Physicochemical characterization of synthesized resins was assessed by a combination of spectroscopy, scanning electron microscopy, viscometry, porosity, and mechanical tests. Adherence of Candida albicans cells and cellular compatibility assays were performed to explore biocompatibility and microbial adhesion of standard and novel materials. Our results show that introduction of biocompatible metal nanoparticles is a suitable means for the improvement of conventional acrylic dental resins.

Biocompatible Metal-Oxide Nanoparticles: Nanotechnology Improvement of Conventional Prosthetic Acrylic Resins

International Nuclear Information System (INIS)

Acosta-Torres, L.S.; Lopez-Marin, L.M.; Padron, G.H.; Castano, V.M.; Nunez-Anita, R.E.

2011-01-01

Nowadays, most products for dental restoration are produced from acrylic resins based on heat-cured Poly(Methyl Methacrylate) (PMMA). The addition of metal nanoparticles to organic materials is known to increase the surface hydrophobicity and to reduce adherence to biomolecules. This paper describes the use of nano structured materials, TiO 2 and Fe 2 O 3 , for simultaneously coloring and/or improving the antimicrobial properties of PMMA resins. Nanoparticles of metal oxides were included during suspension polymerization to produce hybrid metal oxides-alginate-containing PMMA. Metal oxide nanoparticles were characterized by dynamic light scattering, and X-ray diffraction. Physicochemical characterization of synthesized resins was assessed by a combination of spectroscopy, scanning electron microscopy, viscometry, porosity, and mechanical tests. Adherence of Candida albicans cells and cellular compatibility assays were performed to explore biocompatibility and microbial adhesion of standard and novel materials. Our results show that introduction of biocompatible metal nanoparticles is a suitable means for the improvement of conventional acrylic dental resins.

In vitro cytotoxicity of iron oxide nanoparticles: effects of chitosan and polyvinyl alcohol as stabilizing agents

Science.gov (United States)

Tran, Phong A.; Nguyen, Hiep T.; Fox, Kate; Tran, Nhiem

2018-03-01

Iron oxide magnetic nanoparticles have significant potential in biomedical applications such as in diagnosis, imaging and therapeutic agent delivery. The choice of stabilizers and surface functionalization is important as it is known to strongly influence the cytotoxicity of the nanoparticles. The present study aimed at investigating the effects of surface charges on the cytotoxicity of iron oxide nanoparticles. We used a co-precipitation method to synthesize iron oxide nanoparticles which were then stabilized with either chitosan (CS) or polyvinyl alcohol (PVA) which have net positive charge and zero charge at physiological pH, respectively. The nanoparticles were characterized in terms of size, charges and chemical oxidation state. Cytotoxicity of the nanoparticles was assessed using mouse fibroblast cells and was correlated with surface charges of the nanoparticles and their aggregation.

Nanostructural evolution from nanosheets to one-dimensional nanoparticles for manganese oxide

International Nuclear Information System (INIS)

Pan, Hongmei; Kong, Xingang; Wen, Puhong; Kitayama, Tomonori; Feng, Qi

2012-01-01

Highlights: ► Nanosheets were transformed to other one-dimensional nanoparticles. ► Nanofibers, nanotubes, nanoribbons, and nanobelts were obtained. ► Nanoparticle morphology can be controlled with organic amines. ► Organic amines act as morphology directing agent. -- Abstract: This paper introduces a novel hydrothermal soft chemical synthesis process for manganese oxide nanostructured particles using two-dimensional manganese oxide nanosheets as precursor. In this process, a birnessite-type manganese oxide with a layered structure was exfoliated into its elementary layer nanosheets, and then the nanosheets were hydrothermally treated to transform the two-dimensional morphology of the nanosheets to one-dimensional nanoparticles. The manganese oxide nanofibers, nanotubes, nanobelts, nanoribbons, and fabric-ribbon-like particles constructed from nanofibers or nanobelts were obtained using this hydrothermal soft chemical process. The nanostructural evolution from the two-dimensional nanosheets to the one-dimensional nanoparticles was characterized by XRD, SEM, TEM, and TG-DTA analysis. The morphology and nanostructure of the products are strongly dependent on the molecular dimension of organic amine cations added in the reaction system. The organic amine cations act as a morphology directing agent in the nanostructural evolution process.

Monte Carlo simulations for dose enhancement in cancer treatment using bismuth oxide nanoparticles implanted in brain soft tissue.

Science.gov (United States)

Taha, Eslam; Djouider, Fathi; Banoqitah, Essam

2018-03-26

The objective of this work is to study the dosimetric performances of bismuth oxide nanoparticles implanted in tumors in cancer radiotherapy. GEANT4 based Monte Carlo numerical simulations were performed to assess dose enhancement distributions in and around a 1 × 1 × 1 cm 3 tumor implanted with different concentrations of bismuth oxide and irradiated with low energies 125 I, 131 Cs, and 103 Pd radioactive sources. Dose contributions were considered from photoelectrons, Auger electrons, and characteristic X-rays. Our results show the dose enhancement increased with increasing both bismuth oxide concentration in the target and photon energy. A dose enhancement factor up to 18.55 was obtained for a concentration of 70 mg/g of bismuth oxide in the tumor when irradiated with 131 Cs source. This study showed that bismuth oxide nanoparticles are innovative agents that could be potentially applicable to in vivo cancer radiotherapy due to the fact that they induce a highly localized energy deposition within the tumor.

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

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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.

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)

Biogenic copper oxide nanoparticles synthesis using Tabernaemontana divaricate leaf extract and its antibacterial activity against urinary tract pathogen.

Science.gov (United States)

Sivaraj, Rajeshwari; Rahman, Pattanathu K S M; Rajiv, P; Salam, Hasna Abdul; Venckatesh, R

2014-12-10

This investigation explains the biosynthesis and characterization of copper oxide nanoparticles from an Indian medicinal plant by an eco-friendly method. The main objective of this study is to synthesize copper oxide nanoparticles from Tabernaemontana divaricate leaves through a green chemistry approach. Highly stable, spherical copper oxide nanoparticles were synthesized by using 50% concentration of Tabernaemontana leaf extract. Formation of copper oxide nanoparticles have been characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM) analysis. All the analyses revealed that copper oxide nanoparticles were 48±4nm in size. Functional groups and chemical composition of copper oxide were also confirmed. Antimicrobial activity of biogenic copper oxide nanoparticles were investigated and maximum zone of inhibition was found in 50μg/ml copper oxide nanoparticles against urinary tract pathogen (Escherichia coli). Copyright © 2014 Elsevier B.V. All rights reserved.

Biogenic copper oxide nanoparticles synthesis using Tabernaemontana divaricate leaf extract and its antibacterial activity against urinary tract pathogen

Science.gov (United States)

Sivaraj, Rajeshwari; Rahman, Pattanathu K. S. M.; Rajiv, P.; Salam, Hasna Abdul; Venckatesh, R.

2014-12-01

This investigation explains the biosynthesis and characterization of copper oxide nanoparticles from an Indian medicinal plant by an eco-friendly method. The main objective of this study is to synthesize copper oxide nanoparticles from Tabernaemontana divaricate leaves through a green chemistry approach. Highly stable, spherical copper oxide nanoparticles were synthesized by using 50% concentration of Tabernaemontana leaf extract. Formation of copper oxide nanoparticles have been characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM) analysis. All the analyses revealed that copper oxide nanoparticles were 48 ± 4 nm in size. Functional groups and chemical composition of copper oxide were also confirmed. Antimicrobial activity of biogenic copper oxide nanoparticles were investigated and maximum zone of inhibition was found in 50 μg/ml copper oxide nanoparticles against urinary tract pathogen (Escherichia coli).

HIGHLY MICROBIAL RESISTANT GRAPHEME OXIDE NANOPARTICLES: SYNTHESIS, CHARACTERIZATION AND ITS ANTIBACTERIAL ACTIVITY

OpenAIRE

Vijaylaxmee Mishra; Richa Sharma

2014-01-01

The present work deigned to prepare graphene oxide nanoparticles and their antimicrobial activity has been evaluated. Graphene oxide is a singal layer of carbon arranged in a hexagonal pattern the basal planes and the edges of graphene oxide nanoparticles contain functional exogenous groups such as hydroxyl, carbonyl and epoxy group, which not only expand the interlayer distance but also make the atomic thick layer hydrophilic. Most important application in area related to transparent conduct...

Gas Sensors Based on Tin Oxide Nanoparticles Synthesized from a Mini-Arc Plasma Source

Directory of Open Access Journals (Sweden)

Ganhua Lu

2006-01-01

Full Text Available Miniaturized gas sensors or electronic noses to rapidly detect and differentiate trace amount of chemical agents are extremely attractive. In this paper, we report on the fabrication and characterization of a functional tin oxide nanoparticle gas sensor. Tin oxide nanoparticles are first synthesized using a convenient and low-cost mini-arc plasma source. The nanoparticle size distribution is measured online using a scanning electrical mobility spectrometer (SEMS. The product nanoparticles are analyzed ex-situ by high resolution transmission electron microscopy (HRTEM for morphology and defects, energy dispersive X-ray (EDX spectroscopy for elemental composition, electron diffraction for crystal structure, and X-ray photoelectron spectroscopy (XPS for surface composition. Nonagglomerated rutile tin oxide (SnO2 nanoparticles as small as a few nm have been produced. Larger particles bear a core-shell structure with a metallic core and an oxide shell. The nanoparticles are then assembled onto an e-beam lithographically patterned interdigitated electrode using electrostatic force to fabricate the gas sensor. The nanoparticle sensor exhibits a fast response and a good sensitivity when exposed to 100 ppm ethanol vapor in air.

Facile radiolytic synthesis of ruthenium nanoparticles on graphene oxide and carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Rojas, J.V., E-mail: jvrojas@vcu.edu [Mechanical and Nuclear Engineering Department, Virginia Commonwealth University, 401 West Main Street, Richmond, Virginia, 23284 (United States); Toro-Gonzalez, M.; Molina-Higgins, M.C. [Mechanical and Nuclear Engineering Department, Virginia Commonwealth University, 401 West Main Street, Richmond, Virginia, 23284 (United States); Castano, C.E., E-mail: cecastanolond@vcu.edu [Nanomaterials Core Characterization Facility, Chemical and Life Science Engineering Department, Virginia Commonwealth University, 601 West Main Street, Richmond, Virginia, 23284 (United States)

2016-03-15

Graphical abstract: - Highlights: • Facile radiolytic synthesis of Ru nanoparticles on graphene oxide and carbon nanotubes. • Homogeneously distributed Rh nanoparticles on supports are ∼2.5 nm in size. • Simultaneous reduction of graphene oxide and Ru ions occurs during the synthesis. • Ru-O bonds evidenced the interaction of the nanoparticles with the support. - Abstract: Ruthenium nanoparticles on pristine (MWCNT) and functionalized carbon nanotubes (f-MWCNT), and graphene oxide have been prepared through a facile, single step radiolytic method at room temperature, and ambient pressure. This synthesis process relies on the interaction of high energy gamma rays from a {sup 60}Co source with the water in the aqueous solutions containing the Ru precursor, leading to the generation of highly reducing species that further reduce the Ru metal ions to zero valence state. Transmission electron microscopy and X-Ray diffraction revealed that the nanoparticles were homogeneously distributed on the surface of the supports with an average size of ∼2.5 nm. X-ray Photoelectron spectroscopy analysis showed that the interaction of the Ru nanoparticles with the supports occurred through oxygenated functionalities, creating metal-oxygen bonds. This method demonstrates to be a simple and clean approach to produce well dispersed nanoparticles on the aforementioned supports without the need of any hazardous chemical.

Facile radiolytic synthesis of ruthenium nanoparticles on graphene oxide and carbon nanotubes

International Nuclear Information System (INIS)

Rojas, J.V.; Toro-Gonzalez, M.; Molina-Higgins, M.C.; Castano, C.E.

2016-01-01

Graphical abstract: - Highlights: • Facile radiolytic synthesis of Ru nanoparticles on graphene oxide and carbon nanotubes. • Homogeneously distributed Rh nanoparticles on supports are ∼2.5 nm in size. • Simultaneous reduction of graphene oxide and Ru ions occurs during the synthesis. • Ru-O bonds evidenced the interaction of the nanoparticles with the support. - Abstract: Ruthenium nanoparticles on pristine (MWCNT) and functionalized carbon nanotubes (f-MWCNT), and graphene oxide have been prepared through a facile, single step radiolytic method at room temperature, and ambient pressure. This synthesis process relies on the interaction of high energy gamma rays from a "6"0Co source with the water in the aqueous solutions containing the Ru precursor, leading to the generation of highly reducing species that further reduce the Ru metal ions to zero valence state. Transmission electron microscopy and X-Ray diffraction revealed that the nanoparticles were homogeneously distributed on the surface of the supports with an average size of ∼2.5 nm. X-ray Photoelectron spectroscopy analysis showed that the interaction of the Ru nanoparticles with the supports occurred through oxygenated functionalities, creating metal-oxygen bonds. This method demonstrates to be a simple and clean approach to produce well dispersed nanoparticles on the aforementioned supports without the need of any hazardous chemical.

Laser sintering of magnesia with nanoparticles of iron oxide and aluminum oxide

International Nuclear Information System (INIS)

García, L.V.; Mendivil, M.I.; Roy, T.K. Das; Castillo, G.A.; Shaji, S.

2015-01-01

Highlights: • Laser sintered MgO pellets with nanoparticles of Al 2 O 3 and Fe 2 O 3 . • Characterized these pellets by XRD, SEM and XPS. • Spinel formations were observed in both cases. • Changes in morphology and structure were analyzed. - Abstract: Nanoparticles of iron oxide (Fe 2 O 3 , 20–40 nm) and aluminum oxide (Al 2 O 3 , 50 nm) were mixed in different concentrations (3, 5 and 7 wt%) in a magnesium oxide (MgO) matrix. The mixture pellet was irradiated with 532 nm output from a Q-switched Nd:YAG laser using different laser fluence and translation speed for sintering. The refractory samples obtained were analyzed using X-ray diffraction technique, scanning electron microscopy and X-ray photoelectron spectroscopy. The results showed that the samples irradiated at translation speed of 110 μm/s and energy fluence of 1.7 J/cm 2 with a concentration of 5 and 7 wt% of Fe 2 O 3 presented the MgFe 2 O 4 spinel-type phase. With the addition of Al 2 O 3 nanoparticles, at a translation speed of 110 μm/s and energy fluence of 1.7 J/cm 2 , there were the formations of MgAl 2 O 4 spinel phase. The changes in morphologies and microstructure due to laser irradiation were analyzed

Nanostructured Metal Oxides And Mixed Metal Oxides, Methods Of Making These Nanoparticles, And Methods Of Their Use

KAUST Repository

Polshettiwar, Vivek

2013-04-11

Embodiments of the present disclosure provide for nanoparticles, methods of making nanoparticles, methods of using the nanoparticles, and the like. Nanoparticles of the present disclosure can have a variety of morphologies, which may lead to their use in a variety of technologies and processes. Nanoparticles of the present may be used in sensors, optics, mechanics, circuits, and the like. In addition, nanoparticles of the present disclosure may be used in catalytic reactions, for CO oxidation, as super-capacitors, in hydrogen storage, and the like.

Nanostructured Metal Oxides And Mixed Metal Oxides, Methods Of Making These Nanoparticles, And Methods Of Their Use

KAUST Repository

Polshettiwar, Vivek; Fihri, Aziz

2013-01-01

Embodiments of the present disclosure provide for nanoparticles, methods of making nanoparticles, methods of using the nanoparticles, and the like. Nanoparticles of the present disclosure can have a variety of morphologies, which may lead to their use in a variety of technologies and processes. Nanoparticles of the present may be used in sensors, optics, mechanics, circuits, and the like. In addition, nanoparticles of the present disclosure may be used in catalytic reactions, for CO oxidation, as super-capacitors, in hydrogen storage, and the like.

Plasma-induced synthesis of Pt nanoparticles supported on TiO2 nanotubes for enhanced methanol electro-oxidation

Science.gov (United States)

Su, Nan; Hu, Xiulan; Zhang, Jianbo; Huang, Huihong; Cheng, Jiexu; Yu, Jinchen; Ge, Chao

2017-03-01

A Pt/C/TiO2 nanotube composite catalyst was successfully prepared for enhanced methanol electro-oxidation. Pt nanoparticles with a particle size of 2 nm were synthesized by plasma sputtering in water, and anatase TiO2 nanotubes with an inner diameter of approximately 100 nm were prepared by a simple two-step anodization method and annealing process. Field-emission scanning electron microscopy images indicated that the different morphologies of TiO2 synthesized on the surface of Ti foils were dependent on the different anodization parameters. The electrochemical performance of Pt/C/TiO2 catalysts for methanol oxidation showed that TiO2 nanotubes were more suitable for use as Pt nanoparticle support materials than irregular TiO2 short nanorods due to their tubular morphology and better electronic conductivity. X-ray photoelectron spectroscopy characterization showed that the binding energies of the Pt 4f of the Pt/C/TiO2 nanotubes exhibited a slightly positive shift caused by the relatively strong interaction between Pt and the TiO2 nanotubes, which could mitigate the poisoning of the Pt catalyst by COads, and further enhance the electrocatalytic performance. Thus, the as-obtained Pt/C/TiO2 nanotubes composites may become a promising catalyst for methanol electro-oxidation.

Size characterization of metal oxide nanoparticles in commercial sunscreen products

Science.gov (United States)

Bairi, Venu Gopal; Lim, Jin-Hee; Fong, Andrew; Linder, Sean W.

2017-07-01

There is an increase in the usage of engineered metal oxide (TiO2 and ZnO) nanoparticles in commercial sunscreens due to their pleasing esthetics and greater sun protection efficiency. A number of studies have been done concerning the safety of nanoparticles in sunscreen products. In order to do the safety assessment, it is pertinent to develop novel analytical techniques to analyze these nanoparticles in commercial sunscreens. This study is focused on developing analytical techniques that can efficiently determine particle size of metal oxides present in the commercial sunscreens. To isolate the mineral UV filters from the organic matrices, specific procedures such as solvent extraction were identified. In addition, several solvents (hexane, chloroform, dichloromethane, and tetrahydrofuran) have been investigated. The solvent extraction using tetrahydrofuran worked well for all the samples investigated. The isolated nanoparticles were characterized by using several different techniques such as transmission electron microscopy, scanning electron microscopy, dynamic light scattering, differential centrifugal sedimentation, and x-ray diffraction. Elemental analysis mapping studies were performed to obtain individual chemical and morphological identities of the nanoparticles. Results from the electron microscopy techniques were compared against the bulk particle sizing techniques. All of the sunscreen products tested in this study were found to contain nanosized (≤100 nm) metal oxide particles with varied shapes and aspect ratios, and four among the 11 products were showed to have anatase TiO2.

Oxidative stress and toxicity of gold nanoparticles in Mytilus edulis

International Nuclear Information System (INIS)

Tedesco, Sara; Doyle, Hugh; Blasco, Julian; Redmond, Gareth; Sheehan, David

2010-01-01

Gold nanoparticles (AuNP) have potential applications in drug delivery, cancer diagnosis and therapy, food industry and environment remediation. However, little is known about their potential toxicity or fate in the environment. Mytilus edulis was exposed in tanks to750 ppb AuNP (average diameter 5.3 ± 1 nm) for 24 h to study in vivo biological effects of nanoparticles. Traditional biomarkers and an affinity procedure selective for thiol-containing proteins followed by two-dimensional electrophoresis (2DE) separations were used to study toxicity and oxidative stress responses. Results were compared to those obtained for treatment with cadmium chloride, a well known pro-oxidant. M. edulis mainly accumulated AuNP in digestive gland which also showed higher lipid peroxidation. One-dimensional SDS/PAGE (1DE) and 2DE analysis of digestive gland samples revealed decreased thiol-containing proteins for AuNP. Lysosomal membrane stability measured in haemolymph gave lower values for neutral red retention time (NRRT) in both treatments but was greater in AuNP. Oxidative stress occurred within 24 h of AuNP exposure in M. edulis. Previously we showed that larger diameter AuNP caused modest effects, indicating that nanoparticle size is a key factor in biological responses to nanoparticles. This study suggests that M. edulis is a suitable model animal for environmental toxicology studies of nanoparticles.

Dewetting of polymer thin films on modified curved surfaces: preparation of polymer nanoparticles with asymmetric shapes by anodic aluminum oxide templates.

Science.gov (United States)

Liu, Chih-Ting; Tsai, Chia-Chan; Chu, Chien-Wei; Chi, Mu-Huan; Chung, Pei-Yun; Chen, Jiun-Tai

2018-04-18

We study the dewetting behaviors of poly(methyl methacrylate) (PMMA) thin films coated in the cylindrical nanopores of anodic aluminum oxide (AAO) templates by thermal annealing. Self-assembled monolayers (SAMs) of n-octadecyltrichlorosilane (ODTS) are introduced to modify the pore surfaces of the AAO templates to induce the dewetting process. By using scanning electron microscopy (SEM), the dewetting-induced morphology transformation from the PMMA thin films to PMMA nanoparticles with asymmetric shapes can be observed. The sizes of the PMMA nanoparticles can be controlled by the original PMMA solution concentrations. The dewetting phenomena on the modified nanopores are explained by taking into account the excess intermolecular interaction free energy (ΔG). This work opens a new possibility for creating polymer nanoparticles with asymmetric shapes in confined geometries.

Electron spin resonance spectroscopy for immunoassay using iron oxide nanoparticles as probe.

Science.gov (United States)

Jiang, Jia; Tian, Sizhu; Wang, Kun; Wang, Yang; Zang, Shuang; Yu, Aimin; Zhang, Ziwei

2018-02-01

With the help of iron oxide nanoparticles, electron spin resonance spectroscopy (ESR) was applied to immunoassay. Iron oxide nanoparticles were used as the ESR probe in order to achieve an amplification of the signal resulting from the large amount of Fe 3+ ion enclosed in each nanoparticle. Rabbit IgG was used as antigen to test this method. Polyclonal antibody of rabbit IgG was used as antibody to detect the antigen. Iron oxide nanoparticle with a diameter of either 10 or 30 nm was labeled to the antibody, and Fe 3+ in the nanoparticle was probed for ESR signal. The sepharose beads were used as solid phase to which rabbit IgG was conjugated. The nanoparticle-labeled antibody was first added in the sample containing antigen, and the antigen-conjugated sepharose beads were then added into the sample. The nanoparticle-labeled antibody bound to the antigen on sepharose beads was separated from the sample by centrifugation and measured. We found that the detection ranges of the antigen obtained with nanoparticles of different sizes were different because the amount of antibody on nanoparticles of 10 nm was about one order of magnitude higher than that on nanoparticles of 30 nm. When 10 nm nanoparticle was used as probe, the upper limit of detection was 40.00 μg mL -1 , and the analytical sensitivity was 1.81 μg mL -1 . When 30 nm nanoparticle was used, the upper limit of detection was 3.00 μg mL -1 , and the sensitivity was 0.014 and 0.13 μg mL -1 depending on the ratio of nanoparticle to antibody. Graphical abstract Schematic diagram of procedure and ESR spectra.

Ultrastructural Analysis of Human Breast Cancer Cells during Their Overtime Interaction with Cerium Oxide Nanoparticles

KAUST Repository

AlAbbadi, Shatha H.

2016-12-01

Cerium oxide nanoparticles have been proposed as an anticancer agent, thanks to their ability of tuning the redox activity in accordance to different conditions, which lead to selective roles on healthy and cancer cells. Recent evidence suggested the ability of these nanoparticles to be toxic against cancer cells, while confer protection from oxidative stress, toward healthy cells. The main focus of this study was to determine the ultrastructural effects of cerium oxide nanoparticles over multiple incubation time of 1, 3, and 7 days on breast healthy and cancer cells. Cellular characterizations were carried out using electron microscopes, both transmission and scanning electron microscopes, while the viability assessments were performed by propidium iodide and trypan blue viability assays. The obtained results of the viability assays and electron microscopy suggested higher toxic effects on the cancer cell line viability by using a nanoceria dose of 300 μg/mL after 1 day of treatment. Such effects were shown to be preserved at 3 days, and in a longer time point of 7 days. On the contrary, the healthy cells underwent less effects on their viability at time point of 1 and 7 days. The 3 days treatment demonstrated a reduction on the number of cells that did not correlate with an increase of the dead cells, which suggested a possible initial decrease of the cell growth rate, which could be due to the high intracellular loading of nanoparticles. To conclude, the overall result of this experiment suggested that 300 μg/mL of CeO2 nanoparticles is the most suitable dose, within the range and the time point tested, which induces long-lasting cytotoxic effects in breast cancer cells, without harming the normal cells, as highlighted by the viability assays and ultrastructural characterization of electron microscopy analysis.

Synthesis, characterization and antibacterial activity of hybrid chitosan-cerium oxide nanoparticles: As a bionanomaterials.

Science.gov (United States)

Senthilkumar, R P; Bhuvaneshwari, V; Ranjithkumar, R; Sathiyavimal, S; Malayaman, V; Chandarshekar, B

2017-11-01

The hybrid chitosan cerium oxide nanoparticles were prepared for the first time by green chemistry approach using plant leaf extract. The intense peak observed around 292nm in the UV-vis spectrum indicate the formation of cerium oxide nanoparticles. The XRD pattern revealed that the hybrid chitosan-cerium oxide nanoparticles have a polycrystalline structure with cubic fluorite phase. The FTIR spectrum of prepared samples showed the formation of Ce-O bonds and chitosan main chains COC and CO. The FESEM image of hybrid chitosan cerium oxide nanoparticles revealed that the particles are spherical in shape with grains size varying from 23.12nm to 89.91nm. EDAX analysis confirmed the presence of Ce, O, C and N elements in the prepared sample. TEM images showed that the prepared hybrid chitosan-cerium oxide nanoparticles are predominantly uniform in size and most of the particles are spherical in shape with less agglomeration and the particles size varies from 3.61nm to 24.40nm. The prepared chitosan cerium oxide nanoparticles of 50μL concentration showed good antibacterial properties against test pathogens, which was confirmed by the FESEM analysis. The prepared small particle size facilitate that these hybrid ChiCO 2 NPs could effectively be used in biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Oxide-nitride-oxide dielectric stacks with Si nanoparticles obtained by low-energy ion beam synthesis

International Nuclear Information System (INIS)

Ioannou-Sougleridis, V; Dimitrakis, P; Vamvakas, V Em; Normand, P; Bonafos, C; Schamm, S; Mouti, A; Assayag, G Ben; Paillard, V

2007-01-01

Formation of a thin band of silicon nanoparticles within silicon nitride films by low-energy (1 keV) silicon ion implantation and subsequent thermal annealing is demonstrated. Electrical characterization of metal-insulator-semiconductor capacitors reveals that oxide/Si-nanoparticles-nitride/oxide dielectric stacks exhibit enhanced charge transfer characteristics between the substrate and the silicon nitride layer compared to dielectric stacks using unimplanted silicon nitride. Attractive results are obtained in terms of write/erase memory characteristics and data retention, indicating the large potential of the low-energy ion-beam-synthesis technique in SONOS memory technology

From iron coordination compounds to metal oxide nanoparticles.

Science.gov (United States)

Iacob, Mihail; Racles, Carmen; Tugui, Codrin; Stiubianu, George; Bele, Adrian; Sacarescu, Liviu; Timpu, Daniel; Cazacu, Maria

2016-01-01

Various types, shapes and sizes of iron oxide nanoparticles were obtained depending on the nature of the precursor, preparation method and reaction conditions. The mixed valence trinuclear iron acetate, [Fe 2 III Fe II O(CH 3 COO) 6 (H 2 O) 3 ]·2H 2 O (FeAc1), μ 3 -oxo trinuclear iron(III) acetate, [Fe 3 O(CH 3 COO) 6 (H 2 O) 3 ]NO 3 ∙4H 2 O (FeAc2), iron furoate, [Fe 3 O(C 4 H 3 OCOO) 6 (CH 3 OH) 3 ]NO 3 ∙2CH 3 OH (FeF), iron chromium furoate, FeCr 2 O(C 4 H 3 OCOO) 6 (CH 3 OH) 3 ]NO 3 ∙2CH 3 OH (FeCrF), and an iron complex with an original macromolecular ligand (FePAZ) were used as precursors for the corresponding oxide nanoparticles. Five series of nanoparticle samples were prepared employing either a classical thermal pathway (i.e., thermal decomposition in solution, solvothermal method, dry thermal decomposition/calcination) or using a nonconventional energy source (i.e., microwave or ultrasonic treatment) to convert precursors into iron oxides. The resulting materials were structurally characterized by wide-angle X-ray diffraction and Fourier transform infrared, Raman, energy-dispersive X-ray, and X-ray fluorescence spectroscopies, as well as thermogravimetric analysis. The morphology was characterized by transmission electron microscopy, atomic force microscopy and dynamic light scattering. The parameters were varied within each route to fine tune the size and shape of the formed nanoparticles.

From iron coordination compounds to metal oxide nanoparticles

Directory of Open Access Journals (Sweden)

Mihail Iacob

2016-12-01

Full Text Available Various types, shapes and sizes of iron oxide nanoparticles were obtained depending on the nature of the precursor, preparation method and reaction conditions. The mixed valence trinuclear iron acetate, [Fe2IIIFeIIO(CH3COO6(H2O3]·2H2O (FeAc1, μ3-oxo trinuclear iron(III acetate, [Fe3O(CH3COO6(H2O3]NO3∙4H2O (FeAc2, iron furoate, [Fe3O(C4H3OCOO6(CH3OH3]NO3∙2CH3OH (FeF, iron chromium furoate, FeCr2O(C4H3OCOO6(CH3OH3]NO3∙2CH3OH (FeCrF, and an iron complex with an original macromolecular ligand (FePAZ were used as precursors for the corresponding oxide nanoparticles. Five series of nanoparticle samples were prepared employing either a classical thermal pathway (i.e., thermal decomposition in solution, solvothermal method, dry thermal decomposition/calcination or using a nonconventional energy source (i.e., microwave or ultrasonic treatment to convert precursors into iron oxides. The resulting materials were structurally characterized by wide-angle X-ray diffraction and Fourier transform infrared, Raman, energy-dispersive X-ray, and X-ray fluorescence spectroscopies, as well as thermogravimetric analysis. The morphology was characterized by transmission electron microscopy, atomic force microscopy and dynamic light scattering. The parameters were varied within each route to fine tune the size and shape of the formed nanoparticles.

Global DNA methylation and oxidative stress biomarkers in workers exposed to metal oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Liou, Saou-Hsing; Wu, Wei-Te; Liao, Hui-Yi [National Institute of Environmental Health Sciences, National Health Research Institutes, Zhunan, Miaoli County, Taiwan (China); Chen, Chao-Yu; Tsai, Cheng-Yen; Jung, Wei-Ting [Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan (China); Lee, Hui-Ling, E-mail: huilinglee3573@gmail.com [Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan (China)

2017-06-05

Highlights: • Global methylation and oxidative DNA damage levels in nanomaterial handling workers were assessed. • 8-isoprostane in exhaled breath condensate of workers exposed to nanoparticles was higher. • 8-OHdG was negatively correlated with global methylation. • Exposure to metal oxide nanoparticles may lead to global methylation and DNA oxidative damage. - Abstract: This is the first study to assess global methylation, oxidative DNA damage, and lipid peroxidation in workers with occupational exposure to metal oxide nanomaterials (NMs). Urinary and white blood cell (WBC) 8-hydroxydeoxyguanosine (8-OHdG), and exhaled breath condensate (EBC) 8-isoprostane were measured as oxidative stress biomarkers. WBC global methylation was measured as an epigenetic alteration. Exposure to TiO{sub 2}, SiO{sub 2,} and indium tin oxide (ITO) resulted in significantly higher oxidative biomarkers such as urinary 8-OHdG and EBC 8-isoprostane. However, significantly higher WBC 8-OHdG and lower global methylation were only observed in ITO handling workers. Significant positive correlations were noted between WBC and urinary 8-OHdG (Spearman correlation r = 0.256, p = 0.003). Furthermore, a significant negative correlation was found between WBC 8-OHdG and global methylation (r = −0.272, p = 0.002). These results suggest that exposure to metal oxide NMs may lead to global methylation, DNA oxidative damage, and lipid peroxidation.

Influence of synthesis energy on physical properties of the oxide nanoparticles

International Nuclear Information System (INIS)

Medeiros, A.A.S.; Mello, V.S. e; Trajano, M.F.; Alves, S.M.

2014-01-01

Nanoparticles are present in many research areas giving a range of applications, one of them is lubricant technology. Oxide nanoparticles have been used as extreme pressure additives in boundary lubrication with good results. The great challenge of this technology is in control of the nanoparticles dispersion to ensure their actions as anti-wear additive. This study goal was to evaluate the influence of the amount of energy synthesis in the dispersive properties, size and shape of nanoparticles synthesized by microwave, varying the amount of energy transferred during the synthesis process. The morphology of the nanoparticles was evaluated by SEM and XRD spectrum was used to identify the crystallite size and the formation of copper oxides. The results showed that the size and shape of the particle, and consequently the dispersion, are directly related to amount of energy used in the synthesis are directly related. (author)

Systematic study of ligand structures of metal oxide EUV nanoparticle photoresists

KAUST Repository

Jiang, Jing

2015-03-19

Ligand stabilized metal oxide nanoparticle resists are promising candidates for EUV lithography due to their high sensitivity for high-resolution patterning and high etching resistance. As ligand exchange is responsible for the patterning mechanism, we systematically studied the influence of ligand structures of metal oxide EUV nanoparticles on their sensitivity and dissolution behavior. ZrO2 nanoparticles were protected with various aromatic ligands with electron withdrawing and electron donating groups. These nanoparticles have lower sensitivity compared to those with aliphatic ligands suggesting the structures of these ligands is more important than their pka on resist sensitivity. The influence of ligand structure was further studied by comparing the nanoparticles’ solubility for a single type ligand to mixtures of ligands. The mixture of nanoparticles showed improved pattern quality. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Cerium fluoride nanoparticles protect cells against oxidative stress

International Nuclear Information System (INIS)

Shcherbakov, Alexander B.; Zholobak, Nadezhda M.; Baranchikov, Alexander E.; Ryabova, Anastasia V.; Ivanov, Vladimir K.

2015-01-01

A novel facile method of non-doped and fluorescent terbium-doped cerium fluoride stable aqueous sols synthesis is proposed. Intense green luminescence of CeF 3 :Tb nanoparticles can be used to visualize these nanoparticles' accumulation in cells using confocal laser scanning microscopy. Cerium fluoride nanoparticles are shown for the first time to protect both organic molecules and living cells from the oxidative action of hydrogen peroxide. Both non-doped and terbium-doped CeF 3 nanoparticles are shown to provide noteworthy protection to cells against the vesicular stomatitis virus. - Highlights: • Facile method of CeF 3 and CeF 3 :Tb stable aqueous sols synthesis is proposed. • Naked CeF 3 nanoparticles are shown to be non-toxic and to protect cells from the action of H 2 O 2 . • CeF 3 and CeF 3 :Tb nanoparticles are shown to protect living cells against the vesicular stomatitis virus

Cerium fluoride nanoparticles protect cells against oxidative stress

Energy Technology Data Exchange (ETDEWEB)

Shcherbakov, Alexander B.; Zholobak, Nadezhda M. [Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Kyiv D0368 (Ukraine); Baranchikov, Alexander E. [Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, Moscow 119991 (Russian Federation); Ryabova, Anastasia V. [Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow 119991 (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow 115409 (Russian Federation); Ivanov, Vladimir K., E-mail: van@igic.ras.ru [Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, Moscow 119991 (Russian Federation); National Research Tomsk State University, Tomsk 634050 (Russian Federation)

2015-05-01

A novel facile method of non-doped and fluorescent terbium-doped cerium fluoride stable aqueous sols synthesis is proposed. Intense green luminescence of CeF{sub 3}:Tb nanoparticles can be used to visualize these nanoparticles' accumulation in cells using confocal laser scanning microscopy. Cerium fluoride nanoparticles are shown for the first time to protect both organic molecules and living cells from the oxidative action of hydrogen peroxide. Both non-doped and terbium-doped CeF{sub 3} nanoparticles are shown to provide noteworthy protection to cells against the vesicular stomatitis virus. - Highlights: • Facile method of CeF{sub 3} and CeF{sub 3}:Tb stable aqueous sols synthesis is proposed. • Naked CeF{sub 3} nanoparticles are shown to be non-toxic and to protect cells from the action of H{sub 2}O{sub 2}. • CeF{sub 3} and CeF{sub 3}:Tb nanoparticles are shown to protect living cells against the vesicular stomatitis virus.

Recent Advances in Antimicrobial Hydrogels Containing Metal Ions and Metals/Metal Oxide Nanoparticles

Directory of Open Access Journals (Sweden)

Fazli Wahid

2017-11-01

Full Text Available Recently, the rapid emergence of antibiotic-resistant pathogens has caused a serious health problem. Scientists respond to the threat by developing new antimicrobial materials to prevent or control infections caused by these pathogens. Polymer-based nanocomposite hydrogels are versatile materials as an alternative to conventional antimicrobial agents. Cross-linking of polymeric materials by metal ions or the combination of polymeric hydrogels with nanoparticles (metals and metal oxide is a simple and effective approach for obtaining a multicomponent system with diverse functionalities. Several metals and metal oxides such as silver (Ag, gold (Au, zinc oxide (ZnO, copper oxide (CuO, titanium dioxide (TiO2 and magnesium oxide (MgO have been loaded into hydrogels for antimicrobial applications. The incorporation of metals and metal oxide nanoparticles into hydrogels not only enhances the antimicrobial activity of hydrogels, but also improve their mechanical characteristics. Herein, we summarize recent advances in hydrogels containing metal ions, metals and metal oxide nanoparticles with potential antimicrobial properties.

Silica Nanoparticles Induce Oxidative Stress and Autophagy but Not Apoptosis in the MRC-5 Cell Line

Directory of Open Access Journals (Sweden)

Sorina Nicoleta Petrache Voicu

2015-12-01

Full Text Available This study evaluated the in vitro effects of 62.5 µg/mL silica nanoparticles (SiO2 NPs on MRC-5 human lung fibroblast cells for 24, 48 and 72 h. The nanoparticles’ morphology, composition, and structure were investigated using high resolution transmission electron microscopy, selected area electron diffraction and X-ray diffraction. Our study showed a decreased cell viability and the induction of cellular oxidative stress as evidenced by an increased level of reactive oxygen species (ROS, carbonyl groups, and advanced oxidation protein products after 24, 48, and 72 h, as well as a decreased concentration of glutathione (GSH and protein sulfhydryl groups. The protein expression of Hsp27, Hsp60, and Hsp90 decreased at all time intervals, while the level of protein Hsp70 remained unchanged during the exposure. Similarly, the expression of p53, MDM2 and Bcl-2 was significantly decreased for all time intervals, while the expression of Bax, a marker for apoptosis, was insignificantly downregulated. These results correlated with the increase of pro-caspase 3 expression. The role of autophagy in cellular response to SiO2 NPs was demonstrated by a fluorescence-labeled method and by an increased level of LC3-II/LC3-I ratio. Taken together, our data suggested that SiO2 NPs induced ROS-mediated autophagy in MRC-5 cells as a possible mechanism of cell survival.

Oxidative stress response in neural stem cells exposed to different superparamagnetic iron oxide nanoparticles

Czech Academy of Sciences Publication Activity Database

Pongrac, I. M.; Pavičić, I.; Milić, M.; Brkić Ahmed, L.; Babič, Michal; Horák, Daniel; Vinković Vrček, I.; Gajović, S.

2016-01-01

Roč. 11, 26 April (2016), s. 1701-1715 ISSN 1176-9114 R&D Projects: GA ČR(CZ) GC16-01128J EU Projects: European Commission(XE) 316120 - GLOWBRAIN Institutional support: RVO:61389013 Keywords : superparamagnetic iron oxide nanoparticles * biocompatibility * oxidative stress Subject RIV: CD - Macromolecular Chemistry

The Effect of Zinc Oxide Nanoparticles on Safflower Plant Growth and Physiology

Directory of Open Access Journals (Sweden)

Z. Hafizi

2018-02-01

Full Text Available In this paper, a study of the effect of ZnO nanoparticles on safflower growth and physiology was performed. Each of these elements plays a particular role in the plant life, the presence of these elements is necessary for plant’s life cycle and growth. Zinc deficiency causes the biggest problems in safflower’s production. Considering the importance of nanoparticles in today's world, this research investigated the effect of Zinc oxide nanoparticles on the concentration of guaiacol peroxidase, polypeptide oxidase, dehydrogenase and malondialdehyde in four plant sample groups in greenhouse and laboratory conditions. Results of showed that malondialdehyde enzyme increased with different treatments of various concentrations of Zinc oxide. The enzyme guaiacol oxidase increased at concentrations of 100 mg/L and polyphenol oxide at concentrations of 10 and 500 mg/L and dehydrogenase in 1000 mg/L and decreased in other treatments. In addition to showing the effect of nanoparticles in plants, these findings determine the beneficial concentrations of nanoparticles that have a positive effect on the level of enzymes in plants.

Effect of metal oxide nanoparticles on Godavari river water treatment

Science.gov (United States)

Goud, Ravi Kumar; Ajay Kumar, V.; Reddy, T. Rakesh; Vinod, B.; Shravani, S.

2018-05-01

Nowadays there is a continuously increasing worldwide concern for the development of water treatment technologies. In the area of water purification, nanotechnology offers the possibility of an efficient removal of pollutants and germs. Nanomaterials reveal good results than other techniques used in water treatment because of its high surface area to volume ratio. In the present work, iron oxide and copper oxide nanoparticles were synthesized by simple heating method. The synthesized nanoparticles were used to purify Godavari river water. The effect of nanoparticles at 70°C temperature, 12 centimeter of sand bed height and pH of 8 shows good results as compared to simple sand bed filter. The attained values of BOD5, COD and Turbidity were in permissible limit of world health organization.

Characterization of physicochemical and colloidal properties of hydrogel chitosan-coated iron-oxide nanoparticles for cancer therapy

International Nuclear Information System (INIS)

Catalano, E; Di Benedetto, A

2017-01-01

Superparamagnetic iron oxide nanoparticles have recently been investigated for their potential to kill cancer cells with promising results, owing to their ability to be targeted and heated by magnetic fields. In this study, novel hydrogel, chitosan Fe 3 O 4 magnetic nanoparticles were synthesized to induce magnetic hyperthermia, and targeted delivering of chemotherapeutics in the cancer microenvironment. The characteristic properties of synthesized bare and CS-MNPs were analyzed by various analytical methods: X-ray diffraction, Fourier transformed infrared spectroscopy, Scanning electron microscopy and Thermo-gravimetric analysis/differential thermal analysis. Magnetic nanoparticles were successfully synthesized using the co-precipitation method. This synthesis technique resulted in nanoparticles with an average particle size of 16 nm. The pure obtained nanoparticles were then successfully encapsulated with 4-nm-thick chitosan coating. The formation of chitosan on the surface of nanoparticles was confirmed by physicochemical analyses. Heating experiments at safe magnetic field (f = 100 kHz, H =10-20 kA m -1 ) revealed that the maximum achieved temperature of water stable chitosan-coated nanoparticles (50 mg ml -1 ) is fully in agreement with cancer therapy and biomedical applications. (paper)

Characterization of physicochemical and colloidal properties of hydrogel chitosan-coated iron-oxide nanoparticles for cancer therapy

Science.gov (United States)

Catalano, E.; Di Benedetto, A.

2017-05-01

Superparamagnetic iron oxide nanoparticles have recently been investigated for their potential to kill cancer cells with promising results, owing to their ability to be targeted and heated by magnetic fields. In this study, novel hydrogel, chitosan Fe3O4 magnetic nanoparticles were synthesized to induce magnetic hyperthermia, and targeted delivering of chemotherapeutics in the cancer microenvironment. The characteristic properties of synthesized bare and CS-MNPs were analyzed by various analytical methods: X-ray diffraction, Fourier transformed infrared spectroscopy, Scanning electron microscopy and Thermo-gravimetric analysis/differential thermal analysis. Magnetic nanoparticles were successfully synthesized using the co-precipitation method. This synthesis technique resulted in nanoparticles with an average particle size of 16 nm. The pure obtained nanoparticles were then successfully encapsulated with 4-nm-thick chitosan coating. The formation of chitosan on the surface of nanoparticles was confirmed by physicochemical analyses. Heating experiments at safe magnetic field (f = 100 kHz, H =10-20 kA m-1) revealed that the maximum achieved temperature of water stable chitosan-coated nanoparticles (50 mg ml-1) is fully in agreement with cancer therapy and biomedical applications.

Synthesis of iron oxide nanoparticles of narrow size distribution on ...

Indian Academy of Sciences (India)

WINTEC

Abstract. We report here the preparation of nanoparticles of iron oxide in the presence of polysaccharide templates. ... using different chemical methods viz. sonochemical, sol- .... 3.2 Characterization of iron oxide prepared by template assisted ...

In vitro studies on oxidative stress-independent, Ag nanoparticles-induced cell toxicity of Candida albicans, an opportunistic pathogen

Directory of Open Access Journals (Sweden)

Radhakrishnan VS

2018-03-01

Full Text Available Venkatraman Srinivasan Radhakrishnan,1 Surya Prakash Dwivedi,2 Mohammed Haris Siddiqui,3 Tulika Prasad1 1Advanced Instrumentation Research Facility (AIRF, Jawaharlal Nehru University, New Delhi, 2School of Biotechnology, IFTM University, Moradabad, 3Department of Bioengineering, Integral University, Lucknow, Uttar Pradesh, India Abstract: Silver nanoparticles (AgNps have attracted maximal attention among all metal nanoparticles, and the study of their biological properties has gained impetus for further medical adoption. This study evaluated the cellular and molecular mechanisms associated with the action of AgNps against an opportunistic pathogen, Candida albicans. Spherical, stable AgNp (average size 21.6 nm prepared by a chemical reduction method showed minimum inhibitory concentration (required to inhibit the growth of 90% of organisms at 40 µg/mL. AgNps have been reported to induce oxidative stress-mediated programmed cell death through the accumulation of intracellular reactive oxygen species (ROS. However, this study demonstrated that intracellular levels of AgNp-induced ROS could be reversed by using antioxidant ascorbic acid, but the sensitivity of AgNp-treated Candida cells could not be completely reversed. Moreover, in addition to the generation of ROS, the AgNps were found to affect other cellular targets resulting in altered membrane fluidity, membrane microenvironment, ergosterol content, cellular morphology, and ultrastructure. Thus, the generation of ROS does not seem to be the sole major cause of AgNp-mediated cell toxicity in Candida. Rather, the multitargeted action of AgNps, generation of ROS, alterations in ergosterol content, and membrane fluidity together seem to have potentiated anti-Candida action. Thus, this “nano-based drug therapy” is likely to favor broad-spectrum activity, multiple cellular targets, and minimum host toxicity. AgNps, therefore, appear to have the potential to address the challenges in multidrug

Development of highly faceted reduced graphene oxide-coated copper oxide and copper nanoparticles on a copper foil surface

Directory of Open Access Journals (Sweden)

Rebeca Ortega-Amaya

2016-07-01

Full Text Available This work describes the formation of reduced graphene oxide-coated copper oxide and copper nanoparticles (rGO-Cu2ONPs, rGO-CuNPs on the surface of a copper foil supporting graphene oxide (GO at annealing temperatures of 200–1000 °C, under an Ar atmosphere. These hybrid nanostructures were developed from bare copper oxide nanoparticles which grew at an annealing temperature of 80 °C under nitrogen flux. The predominant phase as well as the particle size and shape strongly depend on the process temperature. Characterization with transmission electron microscopy and scanning electron microscopy indicates that Cu or Cu2O nanoparticles take rGO sheets from the rGO network to form core–shell Cu–rGO or Cu2O–rGO nanostructures. It is noted that such ones increase in size from 5 to 800 nm as the annealing temperature increases in the 200–1000 °C range. At 1000 °C, Cu nanoparticles develop a highly faceted morphology, displaying arm-like carbon nanorods that originate from different facets of the copper crystal structure.

Dynamic Behavior of CuZn Nanoparticles under Oxidizing and Reducing Conditions

DEFF Research Database (Denmark)

Holse, Christian; Elkjær, Christian Fink; Nierhoff, Anders Ulrik Fregerslev

2015-01-01

migrate to the Cu surface forming a Cu–Zn surface alloy. The oxidation and reduction dynamics of the CuZn nanoparticles is of great importance to industrial methanol synthesis for which the direct interaction of Cu and ZnO nanocrystals synergistically boosts the catalytic activity. Thus, the present......The oxidation and reduction of CuZn nanoparticles was studied using X-ray photoelectron spectroscopy (XPS) and in situ transmission electron microscopy (TEM). CuZn nanoparticles with a narrow size distribution were produced with a gas-aggregation cluster source in conjunction with mass......-filtration. A direct comparison between the spatially averaged XPS information and the local TEM observations was thus made possible. Upon oxidation in O2, the as-deposited metal clusters transform into a polycrystalline cluster consisting of separate CuO and ZnO nanocrystals. Specifically, the CuO is observed...

Stability of silver nanoparticles: agglomeration and oxidation in biological relevant conditions

Science.gov (United States)

Valenti, Laura E.; Giacomelli, Carla E.

2017-05-01

Silver nanoparticles (Ag-NP) are the most used nanomaterial in consumer products due to the intrinsic antimicrobial capacity of silver. However, Ag-NP may be also harmful to algae, aquatic species, mammalian cells, and higher plants because both Ag+ and nanoparticles are responsible of cell damages. The oxidative dissolution of Ag-NP would proceed to completion under oxic conditions, but the rate and extent of the dissolution depend on several factors. This work correlates the effect of the capping agent (albumin and citrate) with the stability of Ag-NP towards agglomeration in simulated body fluid (SBF) and oxidation in the presence of ROS species (H2O2). Capping provides colloidal stability only through electrostatic means, whereas albumin acts as bulky ligands giving steric and electrostatic repulsion, inhibiting the agglomeration in SBF. However, citrate capping protects Ag-NP from dissolution to a major extent than albumin does because of its reducing power. Moreover, citrate in solution minimizes the oxidation of albumin-coated Ag-NP even after long incubation times. H2O2-induced dissolution proceeds to completion with Ag-NP incubated in SBF, while incubation in citrate leads to an incomplete oxidation. In short, albumin is an excellent capping agent to minimize Ag-NP agglomeration whereas citrate provides a mild-reductive medium that prevents dissolution in biological relevant media as well as in the presence of ROS species. These results provide insight into how the surface properties and media composition affect the release of Ag+ from Ag-NP, related to the cell toxicity and relevant to the storage and lifetime of silver-containing nanomaterials.

Stability of silver nanoparticles: agglomeration and oxidation in biological relevant conditions

Energy Technology Data Exchange (ETDEWEB)

Valenti, Laura E.; Giacomelli, Carla E., E-mail: giacomel@fcq.unc.edu.ar [Universidad Nacional de Córdoba, Ciudad Universitaria, Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) CONICET-UNC, Departamento de Fisicoquímica, Facultad de Ciencias Químicas (Argentina)

2017-05-15

Silver nanoparticles (Ag-NP) are the most used nanomaterial in consumer products due to the intrinsic antimicrobial capacity of silver. However, Ag-NP may be also harmful to algae, aquatic species, mammalian cells, and higher plants because both Ag{sup +} and nanoparticles are responsible of cell damages. The oxidative dissolution of Ag-NP would proceed to completion under oxic conditions, but the rate and extent of the dissolution depend on several factors. This work correlates the effect of the capping agent (albumin and citrate) with the stability of Ag-NP towards agglomeration in simulated body fluid (SBF) and oxidation in the presence of ROS species (H{sub 2}O{sub 2}). Capping provides colloidal stability only through electrostatic means, whereas albumin acts as bulky ligands giving steric and electrostatic repulsion, inhibiting the agglomeration in SBF. However, citrate capping protects Ag-NP from dissolution to a major extent than albumin does because of its reducing power. Moreover, citrate in solution minimizes the oxidation of albumin-coated Ag-NP even after long incubation times. H{sub 2}O{sub 2}-induced dissolution proceeds to completion with Ag-NP incubated in SBF, while incubation in citrate leads to an incomplete oxidation. In short, albumin is an excellent capping agent to minimize Ag-NP agglomeration whereas citrate provides a mild-reductive medium that prevents dissolution in biological relevant media as well as in the presence of ROS species. These results provide insight into how the surface properties and media composition affect the release of Ag{sup +} from Ag-NP, related to the cell toxicity and relevant to the storage and lifetime of silver-containing nanomaterials.

Evaluation of the sonosensitizing properties of nano-graphene oxide in comparison with iron oxide and gold nanoparticles

Science.gov (United States)

Beik, Jaber; Abed, Ziaeddin; Shakeri-Zadeh, Ali; Nourbakhsh, Mitra; Shiran, Mohammad Bagher

2016-07-01

In cancer hyperthermia, ultrasound is considered as an appropriate source of energy to achieve desired therapeutic levels of heating. It is assumed that such a heating is targeted to cancer cells by using nanoparticles as sonosensitization agents. Here, we report the sonosensitizing effects of Nano-Graphene Oxide (NGO) and compare them with gold nanoparticles (AuNPs), Iron Oxide nanoparticles (IONPs). Experiments were conducted to explore the effects of nanoparticle type and concentration, as well as ultrasound power, on transient heating up of the solutions exposed by 1 MHz ultrasound. Nanoparticles concentration was selected from 0.25 to 2.5 mg/ml and the solutions were exposed by ultrasound powers from 1 to 8 W. Real time temperature monitoring was done by a thermocouple and obtained data was analyzed. Temperature profiles of various nanoparticle solutions showed the higher heating rates, in comparison to water. Heating rise was strongly depended on nanoparticles concentration and ultrasound power. AuNPs showed a superior efficiency in heat generation enhancement in comparison to IONPs and NGO. Our result supports the idea of sonosensitizing capabilities of AuNPs, IONPs, and NGO. Targeted hyperthermia may be achievable by preferential loading of tumor with nanoparticles and subsequent ultrasound irradiation.

Shape control of the magnetic iron oxide nanoparticles under different chain length of reducing agents

International Nuclear Information System (INIS)

Ngoi, Kuan Hoon; Chia, Chin-Hua; Zakaria, Sarani; Chiu, Wee Siong

2015-01-01

We report on the effect of using reducing agents with different chain-length on the synthesis of iron oxide nanoparticles by thermal decomposition of iron (III) acetylacetonate in 1-octadecene. This modification allows us to control the shape of nanoparticles into spherical and cubic iron oxide nanoparticles. The highly monodisperse 14 nm spherical nanoparticles are obtained under 1,2-dodecanediol and average 14 nm edge-length cubic iron oxide nanoparticles are obtained under 1,2-tetradecanediol. The structural characterization such as transmission electron microscope (TEM) and X-ray diffraction (XRD) shows similar properties between two particles with different shapes. The vibrating sample magnetometer (VSM) shows no significant difference between spherical and cubic nanoparticles, which are 36 emu/g and 37 emu/g respectively and superparamagnetic in nature

Shape control of the magnetic iron oxide nanoparticles under different chain length of reducing agents

Energy Technology Data Exchange (ETDEWEB)

Ngoi, Kuan Hoon; Chia, Chin-Hua, E-mail: chia@ukm.edu.my; Zakaria, Sarani [School of Applied Physics, Faculty Science and Technology, University Kebangsaan Malaysia 43600 UKM Bangi, Selangor (Malaysia); Chiu, Wee Siong [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Lembah Pantai, Kuala Lumpur (Malaysia)

2015-09-25

We report on the effect of using reducing agents with different chain-length on the synthesis of iron oxide nanoparticles by thermal decomposition of iron (III) acetylacetonate in 1-octadecene. This modification allows us to control the shape of nanoparticles into spherical and cubic iron oxide nanoparticles. The highly monodisperse 14 nm spherical nanoparticles are obtained under 1,2-dodecanediol and average 14 nm edge-length cubic iron oxide nanoparticles are obtained under 1,2-tetradecanediol. The structural characterization such as transmission electron microscope (TEM) and X-ray diffraction (XRD) shows similar properties between two particles with different shapes. The vibrating sample magnetometer (VSM) shows no significant difference between spherical and cubic nanoparticles, which are 36 emu/g and 37 emu/g respectively and superparamagnetic in nature.

Core-shell iron-iron oxide nanoparticles

DEFF Research Database (Denmark)

Kuhn, Luise Theil; Bojesen, A.; Timmermann, L.

2004-01-01

We present studies of the magnetic properties of core-shell iron-iron oxide nanoparticles. By combining Mossbauer and X-ray absorption spectroscopy we have been able to measure the change from a Fe3O4-like to a gamma-Fe2O3-like composition from the interface to the surface. Furthermore, we have...

Optical investigations on indium oxide nano-particles prepared through precipitation method

International Nuclear Information System (INIS)

Seetha, M.; Bharathi, S.; Dhayal Raj, A.; Mangalaraj, D.; Nataraj, D.

2009-01-01

Visible light emitting indium oxide nanoparticles were synthesized by precipitation method. Sodium hydroxide dissolved in ethanol was used as a precipitating agent to obtain indium hydroxide precipitates. Precipitates, thus formed were calcined at 600 deg. C for 1 h to obtain indium oxide nanoparticles. The structure of the particles as determined from the X-Ray diffraction pattern was found to be body centered cubic. The phase transformation of the prepared nanoparticles was analyzed using thermogravimetry. Surface morphology of the prepared nanoparticles was analyzed using high resolution-scanning electron microscopy and transmission electron microscopy. The results of the analysis show cube-like aggregates of size around 50 nm. It was found that the nanoparticles have a strong emission at 427 nm and a weak emission at 530 nm. These emissions were due to the presence of singly ionized oxygen vacancies and the nature of the defect was confirmed through Electron paramagnetic resonance analysis.

Preparation of ciprofloxacin-coated zinc oxide nanoparticles and their antibacterial effects against clinical isolates of Staphylococcus aureus and Escherichia coli

DEFF Research Database (Denmark)

Seif, Sepideh; Kazempour, Zarah Bahri; Pourmand, Mohammad Reza

2011-01-01

In the present research study, ciprofloxacincoated zinc oxide nanoparticles were prepared using a precipitation method. The nature of interactions between zinc oxide nanoparticles and ciprofloxacin (CAS 85721-33-1) was studied by Fourier transform infrared spectroscopy. The results show...... that the carbonyl group in ciprofloxacin is actively involved in forming chemical - rather than physical - bonds with zinc oxide nanoparticles. Also the antibacterial activity of free zinc oxide nanoparticles and ciprofloxacin-coated zinc oxide nanoparticles have been evaluated against different clinical isolates...... of Staphylococcus aureus and Escherichia coli. The free zinc oxide nanoparticles did not show potent antibacterial activity against all test strains. In contrast, only the low concentrations of ciprofloxacincoated zinc oxide nanoparticles (equivalent to the sub-minimum inhibitory concentrations of pure...

Anti-oxidative and inflammatory responses induced by fly ash particles and carbon black in lung epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Diabate, Silvia; Plaumann, Diana; Uebel, Caroline; Weiss, Carsten [Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Eggenstein-Leopoldshafen (Germany); Bergfeldt, Britta [Karlsruhe Institute of Technology, Institute of Technical Chemistry, Eggenstein-Leopoldshafen (Germany)

2011-12-15

Combustion-derived nanoparticles as constituents of ambient particulate matter have been shown to induce adverse health effects due to inhalation. However, the components inducing these effects as well as the biological mechanisms are still not fully understood. The fine fraction of fly ash particles collected from the electrostatic precipitator of a municipal solid waste incinerator was taken as an example for real particles with complex composition released into the atmosphere to study the mechanism of early biological responses of BEAS-2B human lung epithelial cells. The studies include the effects of the water-soluble and -insoluble fractions of the fly ash and the well-studied carbon black nanoparticles were used as a reference. Fly ash induced reactive oxygen species (ROS) and increased the total cellular glutathione (tGSH) content. Carbon black also induced ROS generation; however, in contrast to the fly ash, it decreased the intracellular tGSH. The fly ash-induced oxidative stress was correlated with induction of the anti-oxidant enzyme heme oxygenase-1 and increase of the redox-sensitive transcription factor Nrf2. Carbon black was not able to induce HO-1. ROS generation, tGSH increase and HO-1 induction were only induced by the insoluble fraction of the fly ash, not by the water-soluble fraction. ROS generation and HO-1 induction were markedly inhibited by pre-incubation of the cells with the anti-oxidant N-acetyl cysteine which confirmed the involvement of oxidative stress. Both effects were also reduced by the metal chelator deferoxamine indicating a contribution of bioavailable transition metals. In summary, both fly ash and carbon black induce ROS but only fly ash induced an increase of intracellular tGSH and HO-1 production. Bioavailable transition metals in the solid water-insoluble matrix of the fly ash mostly contribute to the effects. (orig.)

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

Laser sintering of magnesia with nanoparticles of iron oxide and aluminum oxide

Energy Technology Data Exchange (ETDEWEB)

García, L.V.; Mendivil, M.I.; Roy, T.K. Das; Castillo, G.A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66451 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66451 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

2015-05-01

Highlights: • Laser sintered MgO pellets with nanoparticles of Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3}. • Characterized these pellets by XRD, SEM and XPS. • Spinel formations were observed in both cases. • Changes in morphology and structure were analyzed. - Abstract: Nanoparticles of iron oxide (Fe{sub 2}O{sub 3}, 20–40 nm) and aluminum oxide (Al{sub 2}O{sub 3}, 50 nm) were mixed in different concentrations (3, 5 and 7 wt%) in a magnesium oxide (MgO) matrix. The mixture pellet was irradiated with 532 nm output from a Q-switched Nd:YAG laser using different laser fluence and translation speed for sintering. The refractory samples obtained were analyzed using X-ray diffraction technique, scanning electron microscopy and X-ray photoelectron spectroscopy. The results showed that the samples irradiated at translation speed of 110 μm/s and energy fluence of 1.7 J/cm{sup 2} with a concentration of 5 and 7 wt% of Fe{sub 2}O{sub 3} presented the MgFe{sub 2}O{sub 4} spinel-type phase. With the addition of Al{sub 2}O{sub 3} nanoparticles, at a translation speed of 110 μm/s and energy fluence of 1.7 J/cm{sup 2}, there were the formations of MgAl{sub 2}O{sub 4} spinel phase. The changes in morphologies and microstructure due to laser irradiation were analyzed.

Molecular Dynamics Simulations of Silica Nanoparticles Grafted with Poly(ethylene oxide) Oligomer Chains

KAUST Repository

Hong, Bingbing; Panagiotopoulos, Athanassios Z.

2012-01-01

A molecular model of silica nanoparticles grafted with poly(ethylene oxide) oligomers has been developed for predicting the transport properties of nanoparticle organic-hybrid materials (NOHMs). Ungrafted silica nanoparticles in a medium of poly(ethylene

Aerobic oxidation of aldehydes under ambient conditions using supported gold nanoparticle catalysts

DEFF Research Database (Denmark)

Marsden, Charlotte Clare; Taarning, Esben; Hansen, David

2008-01-01

A new, green protocol for producing simple esters by selectively oxidizing an aldehyde dissolved in a primary alcohol has been established, utilising air as the oxidant and supported gold nanoparticles as catalyst. The oxidative esterifications proceed with excellent selectivities at ambient cond...... conditions; the reactions can be performed in an open flask and at room temperature. Benzaldehyde is even oxidised at a reasonable rate below -70 degrees C. Acrolein is oxidised to methyl acrylate in high yield using the same protocol.......A new, green protocol for producing simple esters by selectively oxidizing an aldehyde dissolved in a primary alcohol has been established, utilising air as the oxidant and supported gold nanoparticles as catalyst. The oxidative esterifications proceed with excellent selectivities at ambient...

Interaction effects in magnetic oxide nanoparticle systems

Indian Academy of Sciences (India)

The interaction effects in magnetic nanoparticle system were studied through a Monte Carlo simulation. The results of simulations were compared with two different magnetic systems, namely, iron oxide polymer nanocomposites prepared by polymerization over core and nanocrystalline cobalt ferrite thin films prepared by ...

Electrochemical Glucose Oxidation Using Glassy Carbon Electrodes Modified with Au-Ag Nanoparticles: Influence of Ag Content

Directory of Open Access Journals (Sweden)

Nancy Gabriela García-Morales

2015-01-01

Full Text Available This paper describes the application of glassy carbon modified electrodes bearing Aux-Agy nanoparticles to catalyze the electrochemical oxidation of glucose. In particular, the paper shows the influence of the Ag content on this oxidation process. A simple method was applied to prepare the nanoparticles, which were characterized by transmission electron microscopy, Ultraviolet-Visible spectroscopy, X-ray diffraction spectroscopy, and cyclic voltammetry. These nanoparticles were used to modify glassy carbon electrodes. The effectiveness of these electrodes for electrochemical glucose oxidation was evaluated. The modified glassy carbon electrodes are highly sensitive to glucose oxidation in alkaline media, which could be attributed to the presence of Aux-Agy nanoparticles on the electrode surface. The voltammetric results suggest that the glucose oxidation speed is controlled by the glucose diffusion to the electrode surface. These results also show that the catalytic activity of the electrodes depends on the Ag content of the nanoparticles. Best results were obtained for the Au80-Ag20 nanoparticles modified electrode. This electrode could be used for Gluconic acid (GA production.

Evaluation of the antitumor activity of platinum nanoparticles in the treatment of hepatocellular carcinoma induced in rats.

Science.gov (United States)

Medhat, Amina; Mansour, Somaya; El-Sonbaty, Sawsan; Kandil, Eman; Mahmoud, Mustafa

2017-07-01

This study aimed to evaluate the antitumor activity of platinum nanoparticles compared with cis-platin both in vitro and in vivo in the treatment of hepatocellular carcinoma induced in rats. The treatment efficacy of platinum nanoparticles was evaluated by measuring antioxidant activities against oxidative stress caused by diethylnitrosamine in liver tissue. The measurements included reduced glutathione content and superoxide dismutase activity, as well as malondialdehyde level. Liver function tests were also determined, in addition to the evaluation of serum alpha-fetoprotein, caspase-3, and cytochrome c in liver tissue. Total RNA extraction from liver tissue samples was also done for the relative quantification of B-cell lymphoma 2, matrix metallopeptidase 9, and tumor protein p53 genes. Histopathological examination was also performed for liver tissue. Results showed that platinum nanoparticles are more potent than cis-platin in treatment of hepatocellular carcinoma induced by diethylnitrosamine in rats as it ameliorated the investigated parameters toward normal control animals. These findings were well appreciated with histopathological studies of diethylnitrosamine group treated with platinum nanoparticles, suggesting that platinum nanoparticles can serve as a good therapeutic agent for the treatment of hepatocellular carcinoma which should attract further studies.

Photocatalytic degradation of phenol by iodine doped tin oxide nanoparticles under UV and sunlight irradiation

Energy Technology Data Exchange (ETDEWEB)

Al-Hamdi, Abdullah M.; Sillanpää, Mika [Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Dutta, Joydeep, E-mail: dutta@squ.edu.om [Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 17, 123 Al-Khoudh (Oman)

2015-01-05

Highlights: • A sol–gel method used to synthesize tin oxide nanoparticles. • Nanoparticles of tin oxide doped with different iodine concentrations. • Degradation studies carried up with UV–vis, TOC, HPLC and GC instruments. • 1% iodine doped tin dioxide showed maximum photodegradation efficiency. - Abstract: Iodine doped tin oxide (SnO{sub 2}:I) nanoparticles were prepared by sol–gel synthesis and their photocatalytic activities with phenol as a test contaminant were studied. In the presence of the catalysts, phenol degradation under direct sunlight was comparable to what was achieved under laboratory conditions. Photocatalytic oxidation reactions were studied by varying the catalyst loading, light intensity, illumination time, pH of the reactant and phenol concentration. Upon UV irradiation in the presence of SnO{sub 2}:I nanoparticles, phenol degrades very rapidly within 30 min, forming carboxylic acid which turns the solution acidic. Phenol degradation rate with 1% iodine doped SnO{sub 2} nanoparticles is at least an order of magnitude higher compared to the degradation achieved through undoped SnO{sub 2} nanoparticles under similar illumination conditions.

Photocatalytic degradation of phenol by iodine doped tin oxide nanoparticles under UV and sunlight irradiation

International Nuclear Information System (INIS)

Al-Hamdi, Abdullah M.; Sillanpää, Mika; Dutta, Joydeep

2015-01-01

Highlights: • A sol–gel method used to synthesize tin oxide nanoparticles. • Nanoparticles of tin oxide doped with different iodine concentrations. • Degradation studies carried up with UV–vis, TOC, HPLC and GC instruments. • 1% iodine doped tin dioxide showed maximum photodegradation efficiency. - Abstract: Iodine doped tin oxide (SnO 2 :I) nanoparticles were prepared by sol–gel synthesis and their photocatalytic activities with phenol as a test contaminant were studied. In the presence of the catalysts, phenol degradation under direct sunlight was comparable to what was achieved under laboratory conditions. Photocatalytic oxidation reactions were studied by varying the catalyst loading, light intensity, illumination time, pH of the reactant and phenol concentration. Upon UV irradiation in the presence of SnO 2 :I nanoparticles, phenol degrades very rapidly within 30 min, forming carboxylic acid which turns the solution acidic. Phenol degradation rate with 1% iodine doped SnO 2 nanoparticles is at least an order of magnitude higher compared to the degradation achieved through undoped SnO 2 nanoparticles under similar illumination conditions

Synergistic Effects of Zinc Oxide Nanoparticles and Fatty Acids on Toxicity to Caco-2 Cells

DEFF Research Database (Denmark)

Cao, Yi; Roursgaard, Martin; Kermanizadeh, Ali

2015-01-01

epithelial (Caco-2) cells. The ZnO NPs exposure concentration dependently induced cytotoxicity to Caco-2 cells showing as reduced proliferation and activity measured by 3 different assays. PA exposure induced cytotoxicity, and coexposure to ZnO NPs and PA showed the largest cytotoxic effects. The presence......Fatty acids exposure may increase sensitivity of intestinal epithelial cells to cytotoxic effects of zinc oxide (ZnO) nanoparticles (NPs). This study evaluated the synergistic effects of ZnO NPs and palmitic acid (PA) or free fatty acids (FFAs) mixture (oleic/PA 2:1) on toxicity to human colon...

Morphology and electronic structure of the oxide shell on the surface of iron nanoparticles.

Science.gov (United States)

Wang, Chongmin; Baer, Donald R; Amonette, James E; Engelhard, Mark H; Antony, Jiji; Qiang, You

2009-07-01

An iron (Fe) nanoparticle exposed to air at room temperature will be instantly covered by an oxide shell that is typically approximately 3 nm thick. The nature of this native oxide shell, in combination with the underlying Fe(0) core, determines the physical and chemical behavior of the core-shell nanoparticle. One of the challenges of characterizing core-shell nanoparticles is determining the structure of the oxide shell, that is, whether it is FeO, Fe(3)O(4), gamma-Fe(2)O(3), alpha-Fe(2)O(3), or something else. The results of prior characterization efforts, which have mostly used X-ray diffraction and spectroscopy, electron diffraction, and transmission electron microscopic imaging, have been framed in terms of one of the known Fe-oxide structures, although it is not necessarily true that the thin layer of Fe oxide is a known Fe oxide. In this Article, we probe the structure of the oxide shell on Fe nanoparticles using electron energy loss spectroscopy (EELS) at the oxygen (O) K-edge with a spatial resolution of several nanometers (i.e., less than that of an individual particle). We studied two types of representative particles: small particles that are fully oxidized (no Fe(0) core) and larger core-shell particles that possess an Fe core. We found that O K-edge spectra collected for the oxide shell in nanoparticles show distinct differences from those of known Fe oxides. Typically, the prepeak of the spectra collected on both the core-shell and the fully oxidized particles is weaker than that collected on standard Fe(3)O(4). Given the fact that the origin of this prepeak corresponds to the transition of the O 1s electron to the unoccupied state of O 2p hybridized with Fe 3d, a weak pre-edge peak indicates a combination of the following four factors: a higher degree of occupancy of the Fe 3d orbital; a longer Fe-O bond length; a decreased covalency of the Fe-O bond; and a measure of cation vacancies. These results suggest that the coordination configuration in

Reduced graphene oxide decorated with Fe doped SnO{sub 2} nanoparticles for humidity sensor

Energy Technology Data Exchange (ETDEWEB)

Toloman, D. [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj-Napoca (Romania); Popa, A., E-mail: popa@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj-Napoca (Romania); Stan, M.; Socaci, C.; Biris, A.R. [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj-Napoca (Romania); Katona, G. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, 400028 Cluj-Napoca (Romania); Tudorache, F. [Interdisciplinary Research Department – Field Science & RAMTECH, Al. I. Cuza University, 11 Carol I Blvd., 7000506 Iasi (Romania); Petrila, I. [Interdisciplinary Research Department – Field Science & RAMTECH, Al. I. Cuza University, 11 Carol I Blvd., 7000506 Iasi (Romania); Faculty of Automatic Control and Computer Engineering, Gheorghe Asachi Technical University, 27 Dimitrie Mangeron Street, 700050 Iasi (Romania); Iacomi, F. [Faculty of Physics, Al. I. Cuza University, 11 Carol I Blvd., 7000506 Iasi (Romania)

2017-04-30

Highlights: • Reduced graphene oxide decorated with Fe doped SnO{sub 2} nanoparticles were synthesized. • The decoration of rGO layers with SnO{sub 2}:Fe nanoparticles was highlited by TEM. • The reduction of graphene oxide was evidenced using XRD and FT-IR. • Sensitivity tests for relative humidity (RH) were carried out. • The composite sensor exhibited enhanced sensing response as compared with Fe:SnO{sub 2}. - Abstract: Reduced graphene oxide (rGO) decorated with Fe doped SnO{sub 2} nanoparticles were fabricated via the electrostatic interaction between positively charged modified Fe-doped SnO{sub 2} oxide and negatively charged graphene oxide (GO) in the presence of poly(allylamine) hydrochloride (PAH). The decoration of rGO layers with SnO{sub 2}:Fe nanoparticles was highlited by TEM microsopy. For composite sample the diffraction patterns coincide well with those of SnO{sub 2}:Fe nanoparticles. The reduction of graphene oxide was evidenced using XRD and FT-IR spectroscopy. The formation of SnO{sub 2}:Fe-PAH-graphene composites was confirmed by FT-IR, Raman and EPR spectroscopy. Sensitivity tests for relative humidity (RH) measurements were carried out at five different concentrations of humid air at room temperature. The prepared composite sensor exhibited a higher sensing response as compared with Fe:SnO{sub 2} nanoparticles.

The acute pulmonary and thrombotic effects of cerium oxide nanoparticles after intratracheal instillation in mice

Directory of Open Access Journals (Sweden)

Nemmar A

2017-04-01

Full Text Available Abderrahim Nemmar,1 Suhail Al-Salam,2 Sumaya Beegam,1 Priya Yuvaraju,2 Badreldin H Ali3 1Department of Physiology, 2Department of Pathology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE; 3Department of Pharmacology and Clinical Pharmacy, College of Medicine & Health Sciences, Sultan Qaboos University, Muscat, Al-Khod, Sultanate of Oman Abstract: Cerium oxide nanoparticles (CeO2 NPs, used as a diesel fuel catalyst, can be emitted into the ambient air, resulting in exposure to humans by inhalation. Recent studies have reported the development of lung toxicity after pulmonary exposure to CeO2 NPs. However, little is known about the possible thrombotic effects of these NPs. The present study investigated the acute (24 hours effect of intratracheal (IT instillation of either CeO2 NPs (0.1 or 0.5 mg/kg or saline (control on pulmonary and systemic inflammation and oxidative stress and thrombosis in mice. CeO2 NPs induced a significant increase of neutrophils into the bronchoalveolar lavage (BAL fluid with an elevation of tumor necrosis factor α (TNFα and a decrease in the activity of the antioxidant catalase. Lung sections of mice exposed to CeO2 NPs showed a dose-dependent infiltration of inflammatory cells consisting of macrophages and neutrophils. Similarly, the plasma levels of C-reactive protein and TNFα were significantly increased, whereas the activities of catalase and total antioxidant were significantly decreased. Interestingly, CeO2 NPs significantly and dose dependently induced a shortening of the thrombotic occlusion time in pial arterioles and venules. Moreover, the plasma concentrations of fibrinogen and plasminogen activator inhibitor-1 were significantly elevated by CeO2 NPs. The direct addition of CeO2 NPs (1, 5, or 25 µg/mL to mouse whole blood, collected from the inferior vena cava, in vitro neither caused significant platelet aggregation nor affected prothrombin time or partial

Cobalt iron oxide nanoparticles induce cytotoxicity and regulate the apoptotic genes through ROS in human liver cells (HepG2).

Science.gov (United States)

Ahamed, Maqusood; Akhtar, Mohd Javed; Khan, M A Majeed; Alhadlaq, Hisham A; Alshamsan, Aws

2016-12-01

Cobalt iron oxide (CoFe 2 O 4 ) nanoparticles (CIO NPs) have been one of the most widely explored magnetic NPs because of their excellent chemical stability, mechanical hardness and heat generating potential. However, there is limited information concerning the interaction of CIO NPs with biological systems. In this study, we investigated the reactive oxygen species (ROS) mediated cytotoxicity and apoptotic response of CIO NPs in human liver cells (HepG2). Diameter of crystalline CIO NPs was found to be 23nm with a band gap of 1.97eV. CIO NPs induced cell viability reduction and membrane damage, and degree of induction was dose- and time-dependent. CIO NPs were also found to induce oxidative stress revealed by induction of ROS, depletion of glutathione and lower activity of superoxide dismutase enzyme. Real-time PCR data has shown that mRNA level of tumor suppressor gene p53 and apoptotic genes (bax, CASP3 and CASP9) were higher, while the expression level of anti-apoptotic gene bcl-2 was lower in cells following exposure to CIO NPs. Activity of caspase-3 and caspase-9 enzymes was also higher in CIO NPs exposed cells. Furthermore, co-exposure of N-acetyl-cysteine (ROS scavenger) efficiently abrogated the modulation of apoptotic genes along with the prevention of cytotoxicity caused by CIO NPs. Overall, we observed that CIO NPs induced cytotoxicity and apoptosis in HepG2 cells through ROS via p53 pathway. This study suggests that toxicity mechanisms of CIO NPs should be further investigated in animal models. Copyright © 2016 Elsevier B.V. All rights reserved.

Antioxidant Cerium Oxide Nanoparticles in Biology and Medicine

Directory of Open Access Journals (Sweden)

Bryant C. Nelson

2016-05-01

Full Text Available Previously, catalytic cerium oxide nanoparticles (CNPs, nanoceria, CeO2-x NPs have been widely utilized for chemical mechanical planarization in the semiconductor industry and for reducing harmful emissions and improving fuel combustion efficiency in the automobile industry. Researchers are now harnessing the catalytic repertoire of CNPs to develop potential new treatment modalities for both oxidative- and nitrosative-stress induced disorders and diseases. In order to reach the point where our experimental understanding of the antioxidant activity of CNPs can be translated into useful therapeutics in the clinic, it is necessary to evaluate the most current evidence that supports CNP antioxidant activity in biological systems. Accordingly, the aims of this review are three-fold: (1 To describe the putative reaction mechanisms and physicochemical surface properties that enable CNPs to both scavenge reactive oxygen species (ROS and to act as antioxidant enzyme-like mimetics in solution; (2 To provide an overview, with commentary, regarding the most robust design and synthesis pathways for preparing CNPs with catalytic antioxidant activity; (3 To provide the reader with the most up-to-date in vitro and in vivo experimental evidence supporting the ROS-scavenging potential of CNPs in biology and medicine.

One-pot synthesis of graphene supported platinum–cobalt nanoparticles as electrocatalysts for methanol oxidation

International Nuclear Information System (INIS)

Kepenienė, V.; Tamašauskaitė-Tamašiūnaitė, L.; Jablonskienė, J.; Semaško, M.; Vaičiūnienė, J.; Vaitkus, R.; Norkus, E.

2016-01-01

In the present study the graphene supported platinum–cobalt nanoparticles were prepared via microwave synthesis. The composition of prepared catalysts was examined by Inductively Coupled Plasma Optical Emission Spectroscopy. The shape and size of catalyst particles were determined by Transmission Electron Microscopy. The electrocatalytic activity of the graphene supported platinum–cobalt nanoparticles was investigated towards the electro-oxidation of methanol in an alkaline medium. It has been found that the graphene supported platinum–cobalt nanoparticles having the Pt:Co molar ratio 1:7 show the highest activity towards the electro-oxidation of methanol among the catalysts with the Pt:Co molar ratios equal to 1:1 and 1:44, graphene supported bare Co and Pt/C catalysts. - Highlights: • Preparation of graphene supported Pt-Co nanoparticles by microwave synthesis. • Electrocatalysts for oxidation of methanol. • Higher activity of PtCo/graphene towards methanol oxidation.

One-pot synthesis of graphene supported platinum–cobalt nanoparticles as electrocatalysts for methanol oxidation

Energy Technology Data Exchange (ETDEWEB)

Kepenienė, V., E-mail: virginalisk@gmail.com [Department of Catalysis, Center for Physical Sciences and Technology, Vilnius LT 01108 (Lithuania); Tamašauskaitė-Tamašiūnaitė, L.; Jablonskienė, J.; Semaško, M.; Vaičiūnienė, J. [Department of Catalysis, Center for Physical Sciences and Technology, Vilnius LT 01108 (Lithuania); Vaitkus, R. [Faculty of Chemistry, Vilnius University, Vilnius LT 03225 (Lithuania); Norkus, E. [Department of Catalysis, Center for Physical Sciences and Technology, Vilnius LT 01108 (Lithuania)

2016-03-01

In the present study the graphene supported platinum–cobalt nanoparticles were prepared via microwave synthesis. The composition of prepared catalysts was examined by Inductively Coupled Plasma Optical Emission Spectroscopy. The shape and size of catalyst particles were determined by Transmission Electron Microscopy. The electrocatalytic activity of the graphene supported platinum–cobalt nanoparticles was investigated towards the electro-oxidation of methanol in an alkaline medium. It has been found that the graphene supported platinum–cobalt nanoparticles having the Pt:Co molar ratio 1:7 show the highest activity towards the electro-oxidation of methanol among the catalysts with the Pt:Co molar ratios equal to 1:1 and 1:44, graphene supported bare Co and Pt/C catalysts. - Highlights: • Preparation of graphene supported Pt-Co nanoparticles by microwave synthesis. • Electrocatalysts for oxidation of methanol. • Higher activity of PtCo/graphene towards methanol oxidation.

In vitro cardiotoxicity screening of silver and metal oxide nanoparticles using human induced pluripotent stem cell-derived cardiomyocytes

Science.gov (United States)

Exposure risk to silver and metal oxide nanoparticles (NPs) continues to increase due to their widespread use in products and applications. In vivo studies have shown Ag, TiO2 and CeO2 NPs translocate to the heart following various routes of exposure. Thus, it is critical to asse...

NAD+-Carrying Mesoporous Silica Nanoparticles Can Prevent Oxidative Stress-Induced Energy Failures of Both Rodent Astrocytes and PC12 Cells

Science.gov (United States)

Chen, Heyu; Wang, Yao; Zhang, Jixi; Ma, Yingxin; Wang, Caixia; Zhou, Ying; Gu, Hongchen; Ying, Weihai

2013-01-01

Aim To test the hypothesis that NAD+-carrying mesoporous silica nanoparticles (M-MSNs@NAD+) can effectively deliver NAD+ into cells to produce cytoprotective effects. Methods & Materials NAD+ was incorporated into M-MSNs. Primary rat astrocyte cultures and PC12 cells were treated with H2O2, followed by post-treatment with M-MSNs@NAD+. After various durations of the post-treatment, intracellular NAD+ levels, intracellular ATP levels and lactate dehydrogenase (LDH) release were determined. Results & Discussion M-MSNs can be effectively loaded with NAD+. The M-MSNs@NAD+ can significantly attenuate H2O2-induced NAD+ and ATP decreases in both astrocyte cultures and PC12 cells. M-MSNs@NAD+ can also partially prevent the H2O2-induced LDH release from both astrocyte cultures and PC12 cells. In contrast, the NAD+ that is spontaneously released from the M-MSNs@NAD+ is insufficient to prevent the H2O2-induced damage. Conclusions Our study has suggested the first approach that can effectively deliver NAD+ into cells, which provides an important basis both for elucidating the roles of intracellular NAD+ in biological functions and for therapeutic applications of NAD+. Our study has also provided the first direct evidence demonstrating a key role of NAD+ depletion in oxidative stress-induced ATP decreases. PMID:24040179

Green Synthesis of Formulated Zinc Oxide Nanoparticles for Chemical Protection of Skin Care and Related Applications

Science.gov (United States)

Koppolu, Ramya

Nanomaterials have diversified applications based on the unique properties. These nanoparticles and functionalized nanocomposites have been studied in the health care filed. Nanoparticles are mostly used in sunscreens which are a part of human life. These sunscreens consist of titanium dioxide and zinc oxide nanoparticles. Due to the higher band crevices, they help the skin to protect from ultraviolet rays, for instance, ultraviolet B and ultraviolet A. A series of nanostructured zinc oxide nanoparticles were prepared by cost-effective chemical and bioinspired methods and variables were optimized. Highly stable and spherical zinc oxide nanoparticles were formulated by aloe vera ( Aloe barbadensis) plant extract and avocado (Persea americana Mill) fruit extract. The state-of-the-art instrumentation was used to characterize the morphology, elemental composition, and particle size distribution. X-ray diffraction data indicated highly crystalline and ultrafine nanoparticles were obtained from the colloidal methods. The X-ray photoelectron spectroscopy results showed the chemical state of zinc, carbon, and oxygen atoms were well-indexed and are used as fingerprint identification of the elements. Transmission electron microscopy images show the shape of particles were cubic and fiber shape contingent upon the protecting operators and heat treatment conditions. The toxicity studies of zinc oxide nanoparticles were found to cause an increase in nitric oxide, which is protecting against further oxidative stress and appears to be nontoxic.

Efficient internalization of silica-coated iron oxide nanoparticles of different sizes by primary human macrophages and dendritic cells

International Nuclear Information System (INIS)

Kunzmann, Andrea; Andersson, Britta; Vogt, Carmen; Feliu, Neus; Ye Fei; Gabrielsson, Susanne; Toprak, Muhammet S.; Buerki-Thurnherr, Tina; Laurent, Sophie; Vahter, Marie; Krug, Harald; Muhammed, Mamoun; Scheynius, Annika; Fadeel, Bengt

2011-01-01

Engineered nanoparticles are being considered for a wide range of biomedical applications, from magnetic resonance imaging to 'smart' drug delivery systems. The development of novel nanomaterials for biomedical applications must be accompanied by careful scrutiny of their biocompatibility. In this regard, particular attention should be paid to the possible interactions between nanoparticles and cells of the immune system, our primary defense system against foreign invasion. On the other hand, labeling of immune cells serves as an ideal tool for visualization, diagnosis or treatment of inflammatory processes, which requires the efficient internalization of the nanoparticles into the cells of interest. Here, we compare novel monodispersed silica-coated iron oxide nanoparticles with commercially available dextran-coated iron oxide nanoparticles. The silica-coated iron oxide nanoparticles displayed excellent magnetic properties. Furthermore, they were non-toxic to primary human monocyte-derived macrophages at all doses tested whereas dose-dependent toxicity of the smaller silica-coated nanoparticles (30 nm and 50 nm) was observed for primary monocyte-derived dendritic cells, but not for the similarly small dextran-coated iron oxide nanoparticles. No macrophage or dendritic cell secretion of pro-inflammatory cytokines was observed upon administration of nanoparticles. The silica-coated iron oxide nanoparticles were taken up to a significantly higher degree when compared to the dextran-coated nanoparticles, irrespective of size. Cellular internalization of the silica-coated nanoparticles was through an active, actin cytoskeleton-dependent process. We conclude that these novel silica-coated iron oxide nanoparticles are promising materials for medical imaging, cell tracking and other biomedical applications.

Surface modification and functionalization of metal and metal oxide nanoparticles by organic ligands

NARCIS (Netherlands)

Neouze, M.A.; Schubert, U.S.

2008-01-01

Metal or metal oxide nanoparticles possess unique features compared to equivalent larger-scale materials. For applications, it is often necessary to stabilize or functionalize such nanoparticles. Thus, modification of the surface of nanoparticles is an important chemical challenge. In this survey,

Comparison of the Effects of Pre-training Administration of Zinc Oxide and ‎Zinc Oxide Nanoparticles on Long-term Memory of Adult Male Mice

Directory of Open Access Journals (Sweden)

N Issapare

2016-01-01

Full Text Available BACKGROUND AND OBJECTIVE: Zinc oxide nanoparticles are one of the most widely used nanoparticles in fields of industry, medicine, pharmaceutical sciences, cosmetics, and nutrition. Multiple studies have demonstrated the negative effects of zinc oxide nanoparticles on the nervous system, while others have revealed their enhancing effects on the activity of nerve cells, involved in memory processes. The aim of this study was to compare the effects of zinc oxide nanoparticles and zinc oxide on long-term memory of mice. METHODS: In this experimental study, 49 NMRI adult male mice, with the mean weight of 25±5 g, were randomly divided into seven groups, each consisting of seven mice: control group, three treatment groups receiving zinc oxide nanoparticles (1, 2.5, and 5 mg/kg of  zinc oxide nanoparticles, respectively, and three treatment groups receiving zinc oxide (1, 2.5, and 5 mg/kg of zinc oxide, respectively. Intraperitoneal injections were performed before training (electric shock. Passive avoidance memory of mice was evaluated, using the Step-Down device. The latency time to descend the platform was regarded as an indicator of memory on days 1, 3, and 7 following training. FINDINGS: Pre-training administration of zinc oxide nanoparticles and zinc oxide at a dose of 2.5 mg/kg yielded no effects on the motor activity of mice. However, a significant decline was reported in the latency time to descend the platform on days 1, 3, and 7 following training (58±17, 45±13, and 39±14 in the zinc oxide group and 93±18, 62±12, and 14±3 in the nano zinc oxide group, respectively (p<0.01 however, the dosage of 5 mg/kg had less significant short-term effects (130±38, 49±14, and 68±10 in the zinc oxide group and 132±46, 41±13, and 58±24 in the nano zinc oxide group, respectively. Also, the dosage of 1 mg/kg was almost ineffective. CONCLUSION: The results showed that weakened long-term memory, caused by zinc oxide administration, is not

The formation of magnetic carboxymethyl-dextrane-coated iron-oxide nanoparticles using precipitation from an aqueous solution

International Nuclear Information System (INIS)

Makovec, Darko; Gyergyek, Sašo; Primc, Darinka; Plantan, Ivan

2015-01-01

The formation of spinel iron-oxide nanoparticles during the co-precipitation of Fe 3+ /Fe 2+ ions from an aqueous solution in the presence of carboxymethyldextrane (CMD) was studied. To follow the formation of the nanoparticles, a mixture of the Fe ions, CMD and ammonia was heated to different temperatures, while the samples were taken, quenched in liquid nitrogen, freeze-dried and characterized using transmission electron microscopy (TEM), X-ray diffractometry (XRD) and magnetometry. The CMD plays a role in the reactions of the Fe ions' precipitation by partially immobilizing the Fe 3+ ions into a complex. At room temperature, the amorphous material is precipitated. Then, above approximately 30 °C, the spinel nanoparticles form inside the amorphous matrix, and at approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles. The CMD bonded to the nanoparticles' surfaces hinders the mass transport and thus prevents their growth. - Highlights: • The carboxymethyl-dextrane coated iron-oxide nanoparticles were synthesized. • The carboxymethyl-dextrane significantly modifies formation of the spinel nanoparticles. • The spinel nanoparticles are formed inside the amorphous matrix. • At approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles

The formation of magnetic carboxymethyl-dextrane-coated iron-oxide nanoparticles using precipitation from an aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Makovec, Darko [Department for Materials Synthesis, Jožef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia); Gyergyek, Sašo, E-mail: saso.gyergyek@ijs.si [Department for Materials Synthesis, Jožef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia); Primc, Darinka [Department for Materials Synthesis, Jožef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia); Plantan, Ivan [Lek Pharmaceuticals d.d., Mengeš (Slovenia)

2015-03-01

The formation of spinel iron-oxide nanoparticles during the co-precipitation of Fe{sup 3+}/Fe{sup 2+} ions from an aqueous solution in the presence of carboxymethyldextrane (CMD) was studied. To follow the formation of the nanoparticles, a mixture of the Fe ions, CMD and ammonia was heated to different temperatures, while the samples were taken, quenched in liquid nitrogen, freeze-dried and characterized using transmission electron microscopy (TEM), X-ray diffractometry (XRD) and magnetometry. The CMD plays a role in the reactions of the Fe ions' precipitation by partially immobilizing the Fe{sup 3+} ions into a complex. At room temperature, the amorphous material is precipitated. Then, above approximately 30 °C, the spinel nanoparticles form inside the amorphous matrix, and at approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles. The CMD bonded to the nanoparticles' surfaces hinders the mass transport and thus prevents their growth. - Highlights: • The carboxymethyl-dextrane coated iron-oxide nanoparticles were synthesized. • The carboxymethyl-dextrane significantly modifies formation of the spinel nanoparticles. • The spinel nanoparticles are formed inside the amorphous matrix. • At approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles.

Properties of Zinc Oxide Nanoparticles and Their Activity Against Microbes

Science.gov (United States)

Siddiqi, Khwaja Salahuddin; ur Rahman, Aziz; Tajuddin; Husen, Azamal

2018-05-01

Zinc oxide is an essential ingredient of many enzymes, sun screens, and ointments for pain and itch relief. Its microcrystals are very efficient light absorbers in the UVA and UVB region of spectra due to wide bandgap. Impact of zinc oxide on biological functions depends on its morphology, particle size, exposure time, concentration, pH, and biocompatibility. They are more effective against microorganisms such as Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, Sarcina lutea, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Pseudomonas vulgaris, Candida albicans, and Aspergillus niger. Mechanism of action has been ascribed to the activation of zinc oxide nanoparticles by light, which penetrate the bacterial cell wall via diffusion. It has been confirmed from SEM and TEM images of the bacterial cells that zinc oxide nanoparticles disintegrate the cell membrane and accumulate in the cytoplasm where they interact with biomolecules causing cell apoptosis leading to cell death.

Design of near-infrared fluorescent bioactive conjugated functional iron oxide nanoparticles for optical detection of colon cancer

Directory of Open Access Journals (Sweden)

Corem-Salkmon E

2012-10-01

Full Text Available Enav Corem-Salkmon, Benny Perlstein, Shlomo MargelThe Institute of Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan, IsraelBackground: Colon cancer is one of the major causes of death in the Western world. Early detection significantly improves long-term survival for patients with the disease. Near-infrared (NIR fluorescent nanoparticles hold great promise as contrast agents for tumor detection. NIR offers several advantages for bioimaging compared with fluorescence in the visible spectrum, ie, lower autofluorescence of biological tissues, lower absorbance, and consequently deeper penetration into biomatrices.Methods and results: NIR fluorescent iron oxide nanoparticles with a narrow size distribution were prepared by nucleation, followed by controlled growth of thin iron oxide films onto cyanine NIR dye conjugated gelatin-iron oxide nuclei. For functionalization, and in order to increase the NIR fluorescence intensity, the NIR fluorescent iron oxide nanoparticles obtained were coated with human serum albumin containing cyanine NIR dye. Leakage of the NIR dye from these nanoparticles into phosphate-buffered saline solution containing 4% albumin was not detected. The work presented here is a feasibility study to test the suitability of iron oxide-human serum albumin NIR fluorescent nanoparticles for optical detection of colon cancer. It demonstrates that encapsulation of NIR fluorescent dye within these nanoparticles significantly reduces photobleaching of the dye. Tumor-targeting ligands, peanut agglutinin and anticarcinoembryonic antigen antibodies (αCEA, were covalently conjugated with the NIR fluorescent iron oxide-human serum albumin nanoparticles via a poly(ethylene glycol spacer. Specific colon tumor detection was demonstrated in chicken embryo and mouse models for both nonconjugated and the peanut agglutinin-conjugated or αCEA-conjugated NIR fluorescent iron oxide-human serum albumin

Is Neurotoxicity of Metallic Nanoparticles the Cascades of Oxidative Stress?

Science.gov (United States)

Song, Bin; Zhang, YanLi; Liu, Jia; Feng, XiaoLi; Zhou, Ting; Shao, LongQuan

2016-06-01

With the rapid development of nanotechnology, metallic (metal or metal oxide) nanoparticles (NPs) are widely used in many fields such as cosmetics, the food and building industries, and bio-medical instruments. Widespread applications of metallic NP-based products increase the health risk associated with human exposures. Studies revealed that the brain, a critical organ that consumes substantial amounts of oxygen, is a primary target of metallic NPs once they are absorbed into the body. Oxidative stress (OS), apoptosis, and the inflammatory response are believed to be the main mechanisms underlying the neurotoxicity of metallic NPs. Other studies have disclosed that antioxidant pretreatment or co-treatment can reverse the neurotoxicity of metallic NPs by decreasing the level of reactive oxygen species, up-regulating the activities of antioxidant enzymes, decreasing the proportion of apoptotic cells, and suppressing the inflammatory response. These findings suggest that the neurotoxicity of metallic NPs might involve a cascade of events following NP-induced OS. However, additional research is needed to determine whether NP-induced OS plays a central role in the neurotoxicity of metallic NPs, to develop a comprehensive understanding of the correlations among neurotoxic mechanisms and to improve the bio-safety of metallic NP-based products.

Examination of Zinc Oxide Nanoparticles as a Fluorescent Fingerprint Detection Powder

International Nuclear Information System (INIS)

Tun Tun Lin

2010-12-01

Detection of latent fingerprint was performed using zinc oxide nanoparticles which were produced by simple and efficient method in aqueous media from zinc nitrate. Synthesized ZnO nanoparticles were characterized by XRD, SEM and AFM for ZnO purification and particle size examination. In this paper an effort has been made to compare the results of using ZnO nanoparticles and conventional fingerprint powders such as ZnO bulk powder, CaO, TiO2, printer toner powder and graphite. Fingerprints on different materials were also examined by the use of ZnO and Graphite powder, which is currently used in the Central Intelligence Department of Myanmar Police Force.From this research, it was observed that zinc oxide nanoparticles powder produced a much clearer picture of the fingerprints, compared to conventional powders and it has very good quality at sticking to the fingerprint residue but not to the background surface.

Comparison and functionalization study of microemulsion-prepared magnetic iron oxide nanoparticles.

Science.gov (United States)

Okoli, Chuka; Sanchez-Dominguez, Margarita; Boutonnet, Magali; Järås, Sven; Civera, Concepción; Solans, Conxita; Kuttuva, Gunaratna Rajarao

2012-06-05

Magnetic iron oxide nanoparticles (MION) for protein binding and separation were obtained from water-in-oil (w/o) and oil-in-water (o/w) microemulsions. Characterization of the prepared nanoparticles have been performed by TEM, XRD, SQUID magnetometry, and BET. Microemulsion-prepared magnetic iron oxide nanoparticles (ME-MION) with sizes ranging from 2 to 10 nm were obtained. Study on the magnetic properties at 300 K shows a large increase of the magnetization ~35 emu/g for w/o-ME-MION with superparamagnetic behavior and nanoscale dimensions in comparison with o/w-ME-MION (10 emu/g) due to larger particle size and anisotropic property. Moringa oleifera coagulation protein (MOCP) bound w/o- and o/w-ME-MION showed an enhanced performance in terms of coagulation activity. A significant interaction between the magnetic nanoparticles and the protein can be described by changes in fluorescence emission spectra. Adsorbed protein from MOCP is still retaining its functionality even after binding to the nanoparticles, thus implying the extension of this technique for various applications.

Photoluminescence study on amino functionalized dysprosium oxide-zinc oxide composite bifunctional nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Joseph, Aswathy; Praveen, G.L; Abha, K.; Lekha, G.M [Department of Chemistry, University of Kerala, Kariavattom, Kerala 695581 (India); George, Sony, E-mail: emailtosony@gmail.com [Department of Chemistry, University of Kerala, Kariavattom, Kerala 695581 (India)

2012-08-15

An organic dispersion of 9-15 nm size stable dysprosium oxide incorporated zinc oxide nanocomposites exhibiting luminescence in the visible region has been synthesised by a wet chemical precipitation technique at room temperature. Tetraethoxysilane TEOS [(C{sub 2}H{sub 5}O){sub 4}Si], (3-aminopropyl) trimethoxysilane (APTS) and a 1:1 mixture of TEOS-APTS have been used as capping agents to control the particle size as well as to achieve uniform dispersion of composite nanoparticles in methanol medium. X-ray diffractometer (XRD) analysis reveals the formation phase of amino-functionalised colloidal dysprosium oxide incorporated ZnO composite nanoparticles to be of zincite structure. The Transmission Electron Microscopy (TEM) images show that the particles are spheroids in shape, having average crystalline sizes ranging from 9 to 15 nm. The photoluminescence (PL) observed in these composites has been attributed to the presence of near band edge excitonic emission and existence of defect centres. The time correlated single photon counting studies of the composite nanoparticles exhibited three decay pathways. The enhanced PL emission intensity of solid state fluorescence spectra of samples is attributed to the absence of vibrational relaxation process. - Highlights: Black-Right-Pointing-Pointer Nano-composites are synthesised using a one step wet chemical precipitation method. Black-Right-Pointing-Pointer A significant fluorescence life time of 8.25 ns is obtained for the nano-composite. Black-Right-Pointing-Pointer Nano-composite particles exhibited pale yellow fluorescence rather than blue. Black-Right-Pointing-Pointer Vibrational cascade free enhanced fluorescence is obtained for the dry sample.

Controlled synthesis of size-tunable nickel and nickel oxide nanoparticles using water-in-oil microemulsions

International Nuclear Information System (INIS)

Kumar, Ajeet; Saxena, Amit; Shankar, Ravi; Mozumdar, Subho; De, Arnab

2013-01-01

Industrial demands have generated a growing need to synthesize pure metal and metal–oxide nanoparticles of a desired size. We report a novel and convenient method for the synthesis of spherical, size tunable, well dispersed, stable nickel and nickel oxide nanoparticles by reduction of nickel nitrate at room temperature in a TX-100/n-hexanol/cyclohexane/water system by a reverse microemulsion route. We determined that reduction with alkaline sodium borohydrate in nitrogen atmosphere leads to the formation of nickel nanoparticles, while the use of hydrazine hydrate in aerobic conditions leads to the formation of nickel oxide nanoparticles. The influence of several reaction parameters on the size of nickel and nickel oxide nanoparticles were evaluated in detail. It was found that the size can be easily controlled either by changing the molar ratio of water to surfactant or by simply altering the concentration of the reducing agent. The morphology and structure of the nanoparticles were characterized by quasi-elastic light scattering (QELS), transmission electron microscopy (TEM), x-ray diffraction (XRD), electron diffraction analysis (EDA) and energy dispersive x-ray (EDX) spectroscopy. The results show that synthesized nanoparticles are of high purity and have an average size distribution of 5–100 nm. The nanoparticles prepared by our simple methodology have been successfully used for catalyzing various chemical reactions. (paper)

The disclosed transformation of pre-sputtered Ti films into nanoparticles via controlled thermal oxidation

Science.gov (United States)

Awad, M. A.; Raaif, M.

2018-05-01

Nanoparticles of TiO2 were successfully prepared from pre-sputtered Ti films using the controlled thermal oxidation. The effect of oxidation temperature on structural, morphological and optical properties in addition to photocatalysis activity of the sputtered films was tested and explained. Analysis of XRD and EDAX elucidated the enhancement in crystallization and oxygen content with the increase of oxidation temperature. SEM depicted the formation of very fine nanoparticles with no specific border on the films oxidized at 550 and 600 °C, whilst crystallites with larger size of approximately from 16 to 23 nm have been observed for the film oxidized at 650 °C. Both optical transmission and refractive index were increased with increasing the oxidation temperature. A red shift in the absorption edge was obtained for the films oxidized at 650 °C compared to that oxidized at 600 °C. The photocatalysis tests demonstrated the priority of 600 °C nanoparticle films to decompose methyl orange (MO) more than 650 °C treated film.

Anti-Biofilm Efficacy of Nitric Oxide-Releasing Silica Nanoparticles

OpenAIRE

Hetrick, Evan M.; Shin, Jae Ho; Paul, Heather S.; Schoenfisch, Mark H.

2009-01-01

The ability of nitric oxide (NO)-releasing silica nanoparticles to kill biofilm-based microbial cells is reported. Biofilms of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans were formed in vitro and exposed to NO-releasing silica nanoparticles. Replicative viability experiments revealed that ≥ 99% of cells from each type of biofilm were killed via NO release, with the greatest efficacy (≥ 99.999% killing) against gram-negative...

Metal Oxide Nanoparticle Photoresists for EUV Patterning

KAUST Repository

Jiang, Jing

2014-01-01

© 2014SPST. Previous studies of methacrylate based nanoparticle have demonstrated the excellent pattern forming capability of these hybrid materials when used as photoresists under 13.5 nm EUV exposure. HfO2 and ZrO2 methacrylate resists have achieved high resolution (∼22 nm) at a very high EUV sensitivity (4.2 mJ/cm2). Further investigations into the patterning process suggests a ligand displacement mechanism, wherein, any combination of a metal oxide with the correct ligand could generate patterns in the presence of the suitable photoactive compound. The current investigation extends this study by developing new nanoparticle compositions with transdimethylacrylic acid and o-toluic acid ligands. This study describes their synthesis and patterning performance under 248 nm KrF laser (DUV) and also under 13.5 nm EUV exposures (dimethylacrylate nanoparticles) for the new resist compositions.

Plasma-induced synthesis of Pt nanoparticles supported on TiO{sub 2} nanotubes for enhanced methanol electro-oxidation

Energy Technology Data Exchange (ETDEWEB)

Su, Nan [College of Materials Science and Engineering, Nanjing Tech University, Xin-Mo-Fan Road No. 5, 210009, Nanjing, Jiangsu (China); The Synergetic Innovation Center for Advanced Materials, Xin-Mo-Fan Road No. 5, 210009, Nanjing, Jiangsu (China); Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Xin-Mo-Fan Road No. 5, 210009, Nanjing, Jiangsu (China); Hu, Xiulan, E-mail: whoxiulan@163.com [College of Materials Science and Engineering, Nanjing Tech University, Xin-Mo-Fan Road No. 5, 210009, Nanjing, Jiangsu (China); The Synergetic Innovation Center for Advanced Materials, Xin-Mo-Fan Road No. 5, 210009, Nanjing, Jiangsu (China); Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Xin-Mo-Fan Road No. 5, 210009, Nanjing, Jiangsu (China); Zhang, Jianbo; Huang, Huihong; Cheng, Jiexu; Yu, Jinchen; Ge, Chao [College of Materials Science and Engineering, Nanjing Tech University, Xin-Mo-Fan Road No. 5, 210009, Nanjing, Jiangsu (China)

2017-03-31

Highlights: • Pt nanoparticles are synthesized by plasma sputtering in water. • Pt/C/TiO{sub 2} nanotubes shows better mass activity and CO-poisoning tolerance than Pt/C. • TiO{sub 2} nanotubes are more suitable for support materials than TiO{sub 2} small particles. • The metal-support interactions between Pt and TiO{sub 2} nanotubes are detected by XPS. - Abstract: A Pt/C/TiO{sub 2} nanotube composite catalyst was successfully prepared for enhanced methanol electro-oxidation. Pt nanoparticles with a particle size of 2 nm were synthesized by plasma sputtering in water, and anatase TiO{sub 2} nanotubes with an inner diameter of approximately 100 nm were prepared by a simple two-step anodization method and annealing process. Field-emission scanning electron microscopy images indicated that the different morphologies of TiO{sub 2} synthesized on the surface of Ti foils were dependent on the different anodization parameters. The electrochemical performance of Pt/C/TiO{sub 2} catalysts for methanol oxidation showed that TiO{sub 2} nanotubes were more suitable for use as Pt nanoparticle support materials than irregular TiO{sub 2} short nanorods due to their tubular morphology and better electronic conductivity. X-ray photoelectron spectroscopy characterization showed that the binding energies of the Pt 4f of the Pt/C/TiO{sub 2} nanotubes exhibited a slightly positive shift caused by the relatively strong interaction between Pt and the TiO{sub 2} nanotubes, which could mitigate the poisoning of the Pt catalyst by CO{sub ads}, and further enhance the electrocatalytic performance. Thus, the as-obtained Pt/C/TiO{sub 2} nanotubes composites may become a promising catalyst for methanol electro-oxidation.

In vitro antiplasmodial activity of PDDS-coated metal oxide nanoparticles against Plasmodium falciparum

Science.gov (United States)

Jacob Inbaneson, Samuel; Ravikumar, Sundaram

2013-06-01

Malaria is the most important parasitic disease, leading to annual death of about one million people and the Plasmodium falciparum develops resistant to well-established antimalarial drugs. The newest antiplasmodial drug from metal oxide nanoparticles helps in addressing this problem. Commercial nanoparticles such as Fe3O4, MgO, ZrO2, Al2O3 and CeO2 coated with PDDS and all the coated and non-coated nanoparticles were screened for antiplasmodial activity against P. falciparum. The Al2O3 nanoparticles (71.42 ± 0.49 μg ml-1) showed minimum level of IC50 value and followed by MgO (72.33 ± 0.37 μg ml-1) and Fe3O4 nanoparticles (77.23 ± 0.42 μg ml-1). The PDDS-Fe3O4 showed minimum level of IC50 value (48.66 ± 0.45 μg ml-1), followed by PDDS-MgO (60.28 ± 0.42 μg ml-1) and PDDS-CeO2 (67.06 ± 0.61 μg ml-1). The PDDS-coated metal oxide nanoparticles showed superior antiplasmodial activity than the non-PDDS-coated metal oxide nanoparticles. Statistical analysis reveals that, significant in vitro antiplasmodial activity ( P activity and it might be used for the development of antiplasmodial drugs.

Pt nanoparticles embedded on reduced graphite oxide with excellent electrocatalytic properties

Energy Technology Data Exchange (ETDEWEB)

Saravanan, Gengan, E-mail: saravanan3che@gmail.com [Central University of Tamil Nadu, Department of Chemistry, Thiruvarur, 610101 (India); Mohan, Subramanian, E-mail: sanjnamohan@yahoo.com [EMFT Division, CSIR-Central Electrochemical Research Institute, Tamilnadu, Karaikudi 630 006 (India)

2016-11-15

Graphical abstract: RGO/Nano Pt: This study explore the electrocatalytic oxidation performance of reduced graphite oxide (RGO) anchored with nano Pt. This graphene composite reveal superior electrooxidation performance that is associated with the flexible RGO matrix and the uniform distribution of Pt particles, which enhances surface area, fast electron transfer, uniform particle size distribution; consequently, the RGO matrix provides more stability to Pt particles during electrooxidation process. Display Omitted - Highlights: • Greener electrochemical method applied to prepare well-dispersed Pt-rGO. • Pt-rGO large surface area excellent charge transfer better catalytic activity. • Low-cost highly efficient carbon-based electrodes for direct formic acid fuel cell. • rGO an excellent support to anchor Pt nanoparticles on its surface. • Pt-rGO distinctly enhanced current density towards formic acid electrooxidation. - Abstract: Economically viable electrochemical approach has been developed for the synthesis of Pt nanoparticles through electrodeposition technique on the surface of Reduced Graphite Oxide (RGO). Pt nanoparticles embedded Reduced Graphite Oxide on Glassy Carbon Electrode are employed (Pt-rGO/GCE) for electrooxidation of formic acid. Scanning Electron Microscopy (SEM) image and Transmission Electron Microscopy (TEM) image shows that reduced graphite oxide act as an excellent support to anchor the Pt nanoparticles. Cyclic voltammetry results confirmed that Pt-rGO/GCE enhanced current density as many folds than that of bare platinum electrode for electrooxidation of formic acid. X-ray diffraction (XRD) patterns for Pt-graphene composites illustrate that peaks at 69.15 and 23° for Pt (220) and graphene carbon (002) respectively. {sup 13}C NMR spectrum of the electrochemically reduced graphite oxide resonance contains only one peak at 133 ppm which retains graphitic sp{sup 2} carbon and does not contain any oxygenated carbon and the carbonyl

Targeted magnetic iron oxide nanoparticles for tumor imaging and therapy

Directory of Open Access Journals (Sweden)

Xiang-Hong Peng

2008-10-01