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Sample records for nanoparticle suspensions titanium

  1. The influence of natural organic matter and aging on suspension stability in guideline toxicity testing of silver, zinc oxide, and titanium dioxide nanoparticles with Daphnia magna

    DEFF Research Database (Denmark)

    Cupi, Denisa; Hartmann, Nanna Isabella Bloch; Baun, Anders

    2015-01-01

    The present study investigated changes in suspension stability and ecotoxicity of engineered nanoparticles (ENPs) by addition of Suwannee River natural organic matter and aging of stock and test suspensions prior to testing. Acute toxicity tests of silver (Ag), zinc oxide (ZnO), and titanium...... not decrease toxicity significantly. Conversely, the presence of Suwannee River natural organic matter (NOM; 20mgL-1) completely alleviated Ag ENP toxicity in all testing scenarios and did not aid in stabilizing suspensions. In contrast, addition of Suwannee River NOM stabilized ZnO ENP suspensions and did...... in stock suspensions. The authors' results suggest that aging and presence of Suwannee River NOM are important parameters in standard toxicity testing of ENPs, which in some cases may aid in gaining better control over the exposure conditions but in other cases might contribute to agglomeration...

  2. Interactions of ciprofloxacin (CIP), titanium dioxide (TiO{sub 2}) nanoparticles and natural organic matter (NOM) in aqueous suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Elke, E-mail: elke.fries@bgr.de [Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Bureau de Recherches Géologiques et Minières (BRGM), Orléans (France); Crouzet, Catherine; Michel, Caroline; Togola, Anne [Bureau de Recherches Géologiques et Minières (BRGM), Orléans (France)

    2016-09-01

    The aim of the present study was to investigate interactions of the antibiotic ciprofloxacin (CIP), titanium dioxide nanoparticles (TiO{sub 2} NP) and natural organic matter (NOM) in aqueous suspensions. The mean hydrodynamic diameter of particles of TiO{sub 2} NP and NOM in the suspensions ranged from 113 to 255 nm. During batch experiments the radioactivity resulting from {sup 14}CIP was determined in the filtrate (filter pore size 100 nm) by scintillation measurements. Up to 72 h, no significant sorption of NOM to TiO{sub 2} NP was observed at a TiO{sub 2} NP concentration of 5 mg/L. When the concentration of TiO{sub 2} NP was increased to 500 mg/L, a small amount of NOM of 9.5% ± 0.6% was sorbed at 72 h. The low sorption affinity of NOM on TiO{sub 2} NP surfaces could be explained by the negative charge of both components in alkaline media or by the low hydrophobicity of the NOM contents. At a TiO{sub 2} NP concentration of 5 mg L{sup −1}, the sorption of CIP on TiO{sub 2} NP was insignificant (TiO{sub 2} NP/CIP ratio: 10). When the TiO{sub 2} NP/CIP ratio was increased to 1000, a significant amount of 53.6% ± 7.2% of CIP was sorbed on TiO{sub 2} NP under equilibrium conditions at 64 h. In alkaline media, CIP is present mainly as zwitterions which have an affinity to sorb on negatively charged TiO{sub 2} NP surfaces. The sorption of CIP on TiO{sub 2} NP in the range of TiO{sub 2} NP concentrations currently estimated for municipal wastewater treatment plants is estimated to be rather low. The Freundlich sorption coefficients (K{sub F}) in the presence of NOM of 2167 L{sup n} mg mg{sup −n} kg{sup −1} was about 10 times lower than in the absence of NOM. This is an indication that the particle fraction of NOM < 100 nm could play a role as a carrier for ionic organic micro-pollutants as CIP. - Highlights: • Ciprofloxacine (CIP) and titanium dioxide nanoparticles (TiO{sub 2} NP) interact. • Organic carbon (OC) could influence such interactions. • Batch

  3. Influence of pH and media composition on suspension stability of silver, zinc oxide, and titanium dioxide nanoparticles and immobilization of Daphnia magna under guideline testing conditions.

    Science.gov (United States)

    Cupi, Denisa; Hartmann, Nanna B; Baun, Anders

    2016-05-01

    In aquatic toxicity testing of engineered nanoparticles (ENPs) the process of agglomeration is very important as it may alter bioavailability and toxicity. In the present study, we aimed to identify test conditions that are favorable for maintaining stable ENP suspensions. We evaluated the influence of key environmental parameters: pH (2-12) and ionic strength using M7, Soft EPA (S EPA) medium, and Very Soft EPA (VS EPA) medium; and observed the influence of these parameters on zeta potential, zeta average, and acute immobilization of Daphnia magna for three different ENPs. Despite being sterically stabilized, test suspensions of silver (Ag) ENPs formed large agglomerates in both VS EPA and M7 media; and toxicity was found to be higher in VS EPA medium due to increased dissolution. Low-agglomerate suspensions for zinc oxide (ZnO) could be obtained at pH 7 in VS EPA medium, but the increase in dissolution caused higher toxicity than in M7 medium. Titanium dioxide (TiO2) ENPs had a point of zero charge in the range of pH 7-8. At pH 7 in VS EPA, agglomerates with smaller hydrodynamic diameters (~200nm) were present compared to the high ionic strength M7 medium where hydrodynamic diameters reached micrometer range. The stable suspensions of TiO2 ENPs caused immobilization of D. magna, 48-h EC50 value of 13.7mgL(-1) (95% CI, 2.4mg-79.1mgL(-1)); whereas no toxicity was seen in the unstable, highly agglomerated M7 medium suspensions, 48-h EC50 >100mgL(-1). The current study provides a preliminary approach for methodology in testing and assessing stability and toxicity of ENPs in aquatic toxicity tests of regulatory relevance. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. An Investigation on the Thermophysical Properties of a Binary Molten Salt System Containing Both Aluminum Oxide and Titanium Oxide Nanoparticle Suspensions

    Science.gov (United States)

    Giridhar, Kunal

    Molten salts are showing great potential to replace current heat transfer and thermal energy storage fluids in concentrated solar plants because of their capability to maximize thermal energy storage, greater stability, cost effectiveness and significant thermal properties. However one of the major drawbacks of using molten salt as heat transfer fluid is that they are in solid state at room temperature and they have a high freezing point. Hence, significant resources would be required to maintain it in liquid form. If molten salt freezes while in operation, it would eventually damage piping network due to its volume shrinkage along with rendering the entire plant inoperable. It is long known that addition of nanoparticle suspensions has led to significant changes in thermal properties of fluids. In this investigation, aluminum oxide and titanium oxide nanoparticles of varying concentrations are added to molten salt/solar salt system consisting of 60% sodium nitrate and 40% potassium nitrate. Using differential scanning calorimeter, an attempt will be made to investigate changes in heat capacity of system, depression in freezing point and changes in latent heat of fusion. Scanning electron microscope will be used to take images of samples to study changes in micro-structure of mixture, ensure uniform distribution of nanoparticle in system and verify authenticity of materials used for experimentation. Due to enormous magnitude of CSP plant, actual implementation of molten salt system is on a large scale. With this investigation, even microscopic enhancement in heat capacity and slight lowering of freezing point will lead to greater benefits in terms of efficiency and cost of operation of plant. These results will further the argument for viability of molten salt as a heat transfer fluid and thermal storage system in CSP. One of the objective of this experimentation is to also collect experimental data which can be used for establishing relation between concentration

  5. Lactobacillusassisted synthesis of titanium nanoparticles

    Directory of Open Access Journals (Sweden)

    Jha Anal

    2007-01-01

    Full Text Available AbstractAn eco-friendlylactobacillussp. (microbe assisted synthesis of titanium nanoparticles is reported. The synthesis is performed at room temperature. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Ti nanoparticles. Individual nanoparticles as well as a number of aggregates almost spherical in shape having a size of 40–60 nm are found.

  6. Antibacterial effect of hydrogen peroxide-titanium dioxide suspensions in the decontamination of rough titanium surfaces.

    Science.gov (United States)

    Wiedmer, David; Petersen, Fernanda Cristina; Lönn-Stensrud, Jessica; Tiainen, Hanna

    2017-07-01

    The chemical decontamination of infected dental implants is essential for the successful treatment of peri-implantitis. The aim of this study was to assess the antibacterial effect of a hydrogen peroxide-titanium dioxide (H 2 O 2 -TiO 2 ) suspension against Staphylococcus epidermidis biofilms. Titanium (Ti) coins were inoculated with a bioluminescent S. epidermidis strain for 8 h and subsequently exposed to H 2 O 2 with and without TiO 2 nanoparticles or chlorhexidine (CHX). Bacterial regrowth, bacterial load and viability after decontamination were analyzed by continuous luminescence monitoring, live/dead staining and scanning electron microscopy. Bacterial regrowth was delayed on surfaces treated with H 2 O 2 -TiO 2 compared to H 2 O 2 . H 2 O 2 -based treatments resulted in a lower bacterial load compared to CHX. Few viable bacteria were found on surfaces treated with H 2 O 2 and H 2 O 2 -TiO 2 , which contrasted with a uniform layer of dead bacteria for surfaces treated with CHX. H 2 O 2 -TiO 2 suspensions could therefore be considered an alternative approach in the decontamination of dental implants.

  7. Influence of pH and media composition on suspension stability of silver, zinc oxide, and titanium dioxide nanoparticles and immobilization of Daphnia magna under guideline testing conditions

    DEFF Research Database (Denmark)

    Cupi, Denisa; Hartmann, Nanna B.; Baun, Anders

    2016-01-01

    sterically stabilized, test suspensions of silver (Ag) ENPs formed large agglomerates in both VS EPA and M7 media; and toxicity was found to be higher in VS EPA medium due to increased dissolution. Low-agglomerate suspensions for zinc oxide (ZnO) could be obtained at pH 7 in VS EPA medium, but the increase...

  8. Colloidal Plasmonic Titanium Nitride Nanoparticles: Properties and Applications

    DEFF Research Database (Denmark)

    Guler, Urcan; Suslov, Sergey; Kildishev, Alexander V.

    2015-01-01

    Optical properties of colloidal plasmonic titanium nitride nanoparticles are examined with an eye on their photothermal and photocatalytic applications via transmission electron microscopy and optical transmittance measurements. Single crystal titanium nitride cubic nanoparticles with an average ...

  9. The preparation, physicochemical properties, and the cohesive energy of liquid sodium containing titanium nanoparticles

    International Nuclear Information System (INIS)

    Saito, Jun-ichi; Itami, Toshio; Ara, Kuniaki

    2012-01-01

    Liquid sodium containing titanium nanoparticles (LSnanop) of 10-nm diameter was prepared by dispersing titanium nanoparticles (2 at.% Ti) into liquid sodium with the addition of stirring and ultrasonic sound wave. The titanium nanoparticles themselves were prepared by the vapor deposition method. This new liquid metal, LSnanop, shows a remarkable stability due to the Brownian motion of nanoparticles in liquid sodium medium. In addition, the difference of measured heat of reaction to water between this LSnanop and liquid sodium indicates the existence of cohesive energy between the liquid sodium medium and dispersed titanium nanoparticles. The origin of the cohesive energy, which serves to stabilize this new liquid metal, was explained by the model of screened nanoparticles in liquid sodium. In this model, negatively charged nanoparticles with transferred electrons from liquid sodium are surrounded by the positively charged screening shell, which may inhibit the gathering of nanoparticles by the “Coulombic repulsion coating.” The atomic volume of LSnanop shows the shrinkage from the linear law, which also suggests the existence of cohesive energy. The viscosity of LSnanop is almost the same as that of liquid sodium. This behavior was explained by the Einstein equation. The surface tension of LSnanop is 17 % larger than that of liquid sodium. The cohesive energy and the negative adsorption may be responsible to this increase. Titanium nanoparticles in liquid sodium seem to be free from the Coulomb fission. This new liquid metal containing nanoparticles suggests the possibility to prepare various stable suspensions with new properties.

  10. Absorption Spectra of Gold Nanoparticle Suspensions

    Science.gov (United States)

    Anan'eva, M. V.; Nurmukhametov, D. R.; Zverev, A. S.; Nelyubina, N. V.; Zvekov, A. A.; Russakov, D. M.; Kalenskii, A. V.; Eremenko, A. N.

    2018-02-01

    Three gold nanoparticle suspensions are obtained, and mean radii in distributions - (6.1 ± 0.2), (11.9 ± 0.3), and (17.3 ± 0.7) nm - are determined by the transmission electron microscopy method. The optical absorption spectra of suspensions are obtained and studied. Calculation of spectral dependences of the absorption index of suspensions at values of the gold complex refractive index taken from the literature showed a significant deviation of experimental and calculated data in the region of 450-800 nm. Spectral dependences of the absorption of suspensions are simulated within the framework of the Mie-Drude theory taking into account the interband absorption in the form of an additional term in the imaginary part of the dielectric permittivity of the Gaussian type. It is shown that to quantify the spectral dependences in the region of the plasmon absorption band of nanoparticles, correction of the parameters of the interband absorption is necessary in addition to the increase of the relaxation parameter of the Drude theory. Spectral dependences of the dielectric permittivity of gold in nanodimensional state are refined from the solution of the inverse problem. The results of the present work are important for predicting the special features of operation of photonic devices and optical detonators based on gold nanoparticles.

  11. Characterization for rbs of Titanium Oxide thin films grown by Dip Coating in a coloidal suspension of nano structured Titanium Oxide

    International Nuclear Information System (INIS)

    Pedrero, E.; Vigil, E.; Zumeta, I.

    1999-01-01

    The depth of Titanium Oxide thin films grown by Dip Coating in a coloidal suspension of nano structured Titanium Oxide was characterized using Rutherford Backscattering Spectrometry. Film depths are compared in function of bath and suspension parameters

  12. Local heating with titanium nitride nanoparticles

    DEFF Research Database (Denmark)

    Guler, Urcan; Ndukaife, Justus C.; Naik, Gururaj V.

    2013-01-01

    We investigate the feasibility of titanium nitride (TiN) nanoparticles as local heat sources in the near infrared region, focusing on biological window. Experiments and simulations provide promising results for TiN, which is known to be bio-compatible.......We investigate the feasibility of titanium nitride (TiN) nanoparticles as local heat sources in the near infrared region, focusing on biological window. Experiments and simulations provide promising results for TiN, which is known to be bio-compatible....

  13. Standardisation of magnetic nanoparticles in liquid suspension

    Science.gov (United States)

    Wells, James; Kazakova, Olga; Posth, Oliver; Steinhoff, Uwe; Petronis, Sarunas; Bogart, Lara K.; Southern, Paul; Pankhurst, Quentin; Johansson, Christer

    2017-09-01

    Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation, spanning a large number of industry sectors from imaging and actuation based applications in biomedicine and biotechnology, through large-scale environmental remediation uses such as water purification, to engineering-based applications such as position-controlled lubricants and soaps. Continuous advances in their manufacture have produced an ever-growing range of products, each with their own unique properties. At the same time, the characterisation of magnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpret the measurement data. In many cases, the stringent requirements of the end-user technologies dictate that magnetic nanoparticle products should be clearly defined, well characterised, consistent and safe; or to put it another way—standardised. The aims of this document are to outline the concepts and terminology necessary for discussion of magnetic nanoparticles, to examine the current state-of-the-art in characterisation methods necessary for the most prominent applications of magnetic nanoparticle suspensions, to suggest a possible structure for the future development of standardisation within the field, and to identify areas and topics which deserve to be the focus of future work items. We discuss potential roadmaps for the future standardisation of this developing industry, and the likely challenges to be encountered along the way.

  14. Standardisation of magnetic nanoparticles in liquid suspension

    International Nuclear Information System (INIS)

    Wells, James; Kazakova, Olga; Posth, Oliver; Steinhoff, Uwe; Petronis, Sarunas; Bogart, Lara K; Southern, Paul; Pankhurst, Quentin; Johansson, Christer

    2017-01-01

    Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation, spanning a large number of industry sectors from imaging and actuation based applications in biomedicine and biotechnology, through large-scale environmental remediation uses such as water purification, to engineering-based applications such as position-controlled lubricants and soaps. Continuous advances in their manufacture have produced an ever-growing range of products, each with their own unique properties. At the same time, the characterisation of magnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpret the measurement data. In many cases, the stringent requirements of the end-user technologies dictate that magnetic nanoparticle products should be clearly defined, well characterised, consistent and safe; or to put it another way—standardised. The aims of this document are to outline the concepts and terminology necessary for discussion of magnetic nanoparticles, to examine the current state-of-the-art in characterisation methods necessary for the most prominent applications of magnetic nanoparticle suspensions, to suggest a possible structure for the future development of standardisation within the field, and to identify areas and topics which deserve to be the focus of future work items. We discuss potential roadmaps for the future standardisation of this developing industry, and the likely challenges to be encountered along the way. (topical review)

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

    Science.gov (United States)

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

  16. Quantum chemical evaluation for the stability of liquid sodium containing titanium nanoparticles

    International Nuclear Information System (INIS)

    Suzuki, Ai; Inaba, Kenji; Ishizawa, Yukie; Miura, Ryuji; Hatakeyama, Nozomu; Miyamoto, Akira; Saito, Jun-ichi; Ara, Kuniaki

    2015-01-01

    Recently, liquid sodium containing titanium nanoparticles (LSnanop) have attracted considerable attention. In this study, suspension state of Ti nanoparticle in liquid sodium was quantum chemically evaluated. The atomic interaction between Ti nanoparticles and sodium atoms in the liquid sodium medium was investigated. There were some literatures which gained quantum chemical insight into a nanoparticle with the surrounding sodium atom. However, liquid sodium medium itself together with a Ti nanoparticle under the realistic temperature has not yet been investigated theoretically. To overcome the problem of conventional theoretical method, we applied computationally low-load Tight Binding Quantum Chemical Molecular Dynamics (TB-QCMD) calculation method to investigate the suspension state of the Ti nanoparticle in liquid sodium metal. (author)

  17. Thermal transport phenomena in nanoparticle suspensions

    International Nuclear Information System (INIS)

    Cardellini, Annalisa; Fasano, Matteo; Bozorg Bigdeli, Masoud; Chiavazzo, Eliodoro; Asinari, Pietro

    2016-01-01

    Nanoparticle suspensions in liquids have received great attention, as they may offer an approach to enhance thermophysical properties of base fluids. A good variety of applications in engineering and biomedicine has been investigated with the aim of exploiting the above potential. However, the multiscale nature of nanosuspensions raises several issues in defining a comprehensive modelling framework, incorporating relevant molecular details and much larger scale phenomena, such as particle aggregation and their dynamics. The objectives of the present topical review is to report and discuss the main heat and mass transport phenomena ruling macroscopic behaviour of nanosuspensions, arising from molecular details. Relevant experimental results are included and properly put in the context of recent observations and theoretical studies, which solved long-standing debates about thermophysical properties enhancement. Major transport phenomena are discussed and in-depth analysis is carried out for highlighting the role of geometrical (nanoparticle shape, size, aggregation, concentration), chemical (pH, surfactants, functionalization) and physical parameters (temperature, density). We finally overview several computational techniques available at different scales with the aim of drawing the attention on the need for truly multiscale predictive models. This may help the development of next-generation nanoparticle suspensions and their rational use in thermal applications. (topical review)

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

    International Nuclear Information System (INIS)

    Olyveira, Gabriel Molina de; Pessan, Luiz Antonio

    2009-01-01

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

  19. Effects of the silica nanoparticles (NPSiO2 on the stabilization and transport of hazardous nanoparticle suspensions into landfill soil columns

    Directory of Open Access Journals (Sweden)

    Elizabeth Mendes de Oliveira

    Full Text Available Abstract This study evaluates the stability and transport behaviors of hazardous nanoparticles into soil landfills using experimental procedures to simulate the effects of natural silica nanoparticle suspensions during their percolation into the soil layers of municipal waste landfills. For this, we prepared stabilized suspensions of nanoparticle oxides containing silicon (NPSiO2, titanium (NPTiO2, copper (NPCuO and zinc (NPZnO, which are recognized as hazardous to the environment, and we conducted leaching experiments within the soil column by simulating landfills layers and simulating the capture and attenuation of nanomaterials into municipal waste landfills. The results demonstrated that the presence of NPSiO2 in suspensions increases the stable concentrations of copper, zinc and titanium oxides and strongly decreases soil layer effectiveness. In contrast, NPZnO improves effectiveness due to its ability to promote agglomeration and setting conditions, allowing further complexation.

  20. Viscosity, thermal diffusivity and Prandtl number of nanoparticle suspensions

    Institute of Scientific and Technical Information of China (English)

    WANG Buxuan; ZHOU Leping; PENG Xiaofeng

    2004-01-01

    Using our reported experimental data of effective thermal conductivity, specific heat capacity and viscosity for CuO nanoparticle suspensions, the corresponding thermal diffusivity and Prandtl number are calculated. With the hard sphere model and considering effects of particle clustering and surface adsorption, the increase of viscosity for nanoparticle suspension observed is explained. It is shown that the effective thermal conductivity will be strongly affected by the formation and correlated spatial distribution of nanoparticle clusters when compared to viscosity in hosting liquid.

  1. Preparation of titanium-tritium suspension for use in fluorescent tube starters

    International Nuclear Information System (INIS)

    Sastry, K.V.S.; Kulkarni, B.A.

    1997-01-01

    Titanium-tritium suspension is useful in the starter glow bulbs of fluorescent tube lights for initial ionisation. This paper describes the method of preparation and conditions for better yield. (author). 1 tab

  2. Biomolecule-coated metal nanoparticles on titanium.

    Science.gov (United States)

    Christensen, Stephen L; Chatt, Amares; Zhang, Peng

    2012-02-07

    Immobilizations of nanoparticles and biomolecules on biocompatible substrates such as titanium are two promising approaches to bringing new functionalities to Ti-based biomaterials. Herein, we used a variety of X-ray spectroscopic techniques to study and better understand metal-thiolate interactions in biofunctionalized metal nanoparticle systems supported on Ti substrates. Using a facile one-step procedure, a series of Au nanoparticle samples with varied biomolecule coatings ((2-mercatopropionyl)glycine (MPG) and bovine serum albumin (BSA)) and biomolecule concentrations are prepared. Ag and Pd systems are also studied to observe change with varying metal composition. The structure and properties of these biomolecule-coated nanoparticles are investigated with scanning electron microscopy (SEM) and element-specific X-ray techniques, including extended X-ray absorption fine structure (Au L(3)-edge), X-ray absorption near-edge structure (Au L(3), Ag L(3), Pd L(3), and S K-edge), and X-ray photoelectron spectroscopy (Au 4f, Ag 3d, Pd 3d, and S 2p core level). It was found that, by comparison of SEM and X-ray spectroscopy results, the coating of metal nanoparticles with varying model biomolecule systems can have a significant effect on both surface coverage and organization. This work offers a facile chemical method for bio- and nanofunctionalization of Ti substrates as well as provides a physical picture of the structure and bonding of biocoated metal nanoparticles, which may lead to useful applications in orthopedics and biomedicine.

  3. Titanium nitride room-temperature ferromagnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Iu.G., E-mail: morozov@ism.ac.ru [Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, 8 Academician Osipyan Street, Chernogolovka, Moscow Region, 142432 (Russian Federation); Belousova, O.V. [Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, 8 Academician Osipyan Street, Chernogolovka, Moscow Region, 142432 (Russian Federation); Belyakov, O.A. [Ogarev Mordovia State University, Saransk, 68 Bol' shevistskaya Street, 430005 (Russian Federation); Parkin, I.P., E-mail: i.p.parkin@ucl.ac.uk [Department of Chemistry, Materials Chemistry Research Centre, University College London, 20 Gordon Street, London, WC1H 0AJ (United Kingdom); Sathasivam, S. [Department of Chemistry, Materials Chemistry Research Centre, University College London, 20 Gordon Street, London, WC1H 0AJ (United Kingdom); Kuznetcov, M.V., E-mail: maxim1968@mail.ru [All-Russian Research Institute on Problems of Civil Defense and Emergencies of Emergency Control Ministry of Russia (EMERCOM), 7 Davidkovskaya Street, Moscow, 121352 (Russian Federation)

    2016-08-05

    Cubic and near-spherical TiN nanoparticles ranging in average size from 20 to 125 nm were prepared by levitation-jet aerosol synthesis through condensation of titanium vapor in an inert gas flow with gaseous nitrogen injection. The nanoparticles were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD), BET measurements, UV–Vis, FT-IR, Raman spectroscopy, XPS, and vibrating-sample magnetometry. Room-temperature ferromagnetism with maximum magnetization up to 2.5 emu/g was recorded for the nanoparticles. The results indicate that the observed ferromagnetic ordering was related to the defect Ti–N structures on the surface of nanoparticles. This suggestion is in good correlation with the measured spectroscopical data. - Highlights: • Levitation-jet aerosol synthesis of TiN nanoparticles (NPs). • SEM, XRD, BET, UV–vis, FT-IR, Raman, XPS and magnetic characterization of the NPs. • Correlation between optical and XPS measurements data and maximum magnetization of the NPs.

  4. Colloidal Plasmonic Titanium Nitride Nanoparticles: Properties and Applications

    Directory of Open Access Journals (Sweden)

    Guler Urcan

    2015-01-01

    Full Text Available Optical properties of colloidal plasmonic titanium nitride nanoparticles are examined with an eye on their photothermal and photocatalytic applications via transmission electron microscopy and optical transmittance measurements. Single crystal titanium nitride cubic nanoparticles with an average size of 50 nm, which was found to be the optimum size for cellular uptake with gold nanoparticles [1], exhibit plasmon resonance in the biological transparency window and demonstrate a high absorption efficiency. A self-passivating native oxide at the surface of the nanoparticles provides an additional degree of freedom for surface functionalization. The titanium oxide shell surrounding the plasmonic core can create new opportunities for photocatalytic applications.

  5. Dispersion and Stabilization of Photocatalytic TiO2 Nanoparticles in Aqueous Suspension for Coatings Applications

    Directory of Open Access Journals (Sweden)

    Siti Hajar Othman

    2012-01-01

    Full Text Available To produce titanium dioxide (TiO2 nanoparticle coatings, it is desirable that the nanoparticles are dispersed into a liquid solution and remain stable for a certain period of time. Controlling the dispersion and aggregation of the nanoparticles is crucial to exploit the advantages of the nanometer-sized TiO2 particles. In this work, TiO2 nanoparticles were dispersed and stabilized in aqueous suspensions using two common dispersants which were polyacrylic acid (PAA and ammonium polymethacrylate (Darvan C. The effect of parameters such as ultrasonication amplitude and type and amount of dispersants on the dispersibility and stability of the TiO2 aqueous suspensions were examined. Rupture followed by erosion was determined to be the main break up mechanisms when ultrasonication was employed. The addition of dispersant was found to produce more dispersed and more stabilized aqueous suspension. 3 wt.% of PAA with average molecular weight (Mw of 2000 g/mol (PAA 2000 was determined to produce the best and most stable dispersion. The suspensions were then coated on quartz glass, whereby the photocatalytic activity of the coatings was studied via the degradation of formaldehyde gas under UV light. The coatings were demonstrated to be photocatalytically active.

  6. A simple route to prepare stable hydroxyapatite nanoparticles suspension

    International Nuclear Information System (INIS)

    Han Yingchao; Wang Xinyu; Li Shipu

    2009-01-01

    A simple ultrasound assisted precipitation method with addition of glycosaminoglycans (GAGs) is proposed to prepare stable hydroxyapatite (HAP) nanoparticles suspension from the mixture of Ca(H 2 PO 4 ) 2 solution and Ca(OH) 2 solution. The product was characterized by XRD, FT-IR, TEM, HRTEM and particle size, and zeta potential analyzer. TEM observation shows that the suspension is composed of 10-20 nm x 20-50 nm short rod-like and 10-30 nm similar spherical HAP nanoparticles. The number-averaged particle size of stable suspension is about 30 nm between 11.6 and 110.5 nm and the zeta potential is -60.9 mV. The increase of stability of HAP nanoparticles suspension mainly depends on the electrostatic effect and steric effect of GAGs. The HAP nanoparticles can be easily transported into the cancer cells and exhibit good potential as gene or drug carrier system.

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

    Science.gov (United States)

    Lappas, Courtney M

    2015-11-01

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

  8. Optical detection of magnetic nanoparticles in colloidal suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Gimenez, Alejandro J.; Ramirez-Wong, Diana G.; Favela-Camacho, Sarai E. [Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional Unidad Querétaro, Querétaro, México (Mexico); Sanchez, Isaac C. [Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712 (United States); Yáñez-Limón, J.M.; Luna-Bárcenas, Gabriel [Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional Unidad Querétaro, Querétaro, México (Mexico)

    2016-03-15

    This study reports the change of light transmittance and light scattering dispersion by colloidal suspensions of magnetic nanoparticles. Optical changes were observed during the application of transversal magnetic fields to magnetic nanoparticles and nanowires at concentrations spanning from 20 µg/mL to 2 ng/mL. Results show that light scattering modulation is a simple, fast and inexpensive method for detection of magnetic nanoparticles at low concentrations. Frequency and time response of the optical modulation strongly depends on the geometry of the particles. In this regard, light transmittance and scattering measurements may prove useful in characterizing the morphology of suspended nanoparticles. - Highlights: • A simple route to characterize magnetic nanowire suspension is proposed. • Studied concentration as low as 2 ng/mL compares with more complex techniques. • Transmission and scattering modes allow full characterization of nanoparticles.

  9. Development of a Fabrication Process Using Suspension Plasma Spray for Titanium Oxide Photovoltaic Device

    Directory of Open Access Journals (Sweden)

    Hsian Sagr Hadi A

    2017-03-01

    Full Text Available In order to reduce the high costs of conventional materials, and to reduce the power necessary for the deposition of titanium dioxide, titanium tetrabutoxide has been developed in the form of a suspension of TiO2 using water instead of expensive ethanol. To avoid sedimentation of hydroxide particles in the suspension, mechanical milling of the suspension was conducted in order to create diffusion in colloidal suspension before using it as feedstock. Consequently, through the creation of a colloidal suspension, coating deposition was able to be conducted without sedimentation of the hydroxide particles in the suspension during the deposition process. Though an amorphous as-deposited coating was able to be deposited, through post heat treatment at 630 °C for 60 min, the chemical structure became anatase rich. In addition, it was confirmed that the post heat treated anatase rich coating had enough photo-catalytic activity to decolor methylene-blue droplets. From these results, this technique was found to have high potential in the low cost photo-catalytic titanium coating production process.

  10. 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

  11. Mucin secretion induced by titanium dioxide nanoparticles.

    Directory of Open Access Journals (Sweden)

    Eric Y T Chen

    2011-01-01

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

  12. Deposition of silver nanoparticles on titanium surface for antibacterial effect

    Directory of Open Access Journals (Sweden)

    Liao Juan

    2010-04-01

    Full Text Available Liao Juan1, Zhu Zhimin3, Mo Anchun1,2, Li Lei1, Zhang Jingchao11State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, PR China; 2Department of Dental Implant, West China Stomatology Hospital, Sichuan University, Chengdu 610041, PR China; 3Department of Prosthodontics, West China Stomatology Hospital, Sichuan University, Chengdu 610041, PR ChinaAbstract: Microbial colonization on implanted devices and biofilm formation is a recurrent complication in implant surgery and may result in loss of implants. The aim of this study was to deposit silver nanoparticles on a titanium surface to obtain antibacterial properties. In the present study, we prepared a silver nanoparticle-modified titanium (Ti-nAg surface using silanization method. The morphology and chemical components of the Ti-nAg surface were characterized by scanning electron microscopy (SEM equipped with energy-dispersive spectroscopy (EDS. Two species of bacteria, Staphylococcus aureus and Escherichia coli, were utilized to test the antibacterial effect of the Ti-nAg treated surface. The SEM examination revealed that a small quantity of silver nanoparticles was sparsely deposited on the titanium surface. The diameter of these nanoparticles ranged from ten to several hundred nm. EDS analyses revealed that there was 4.26% of Ag present on the surface. After a 24-hour incubation, 94% of Staphylococcus aureus and over 95% of Escherichia coli had been killed on the Ti-nAg surface, and the SEM examination of anti-adhesive efficacy test showed that there were less bacteria attached to Ti-nAg surface than to a control surface of untreated Titanium. These data suggest that silver nanoparticle-modified titanium is a promising material with an antibacterial property that may be used as an implantable biomaterial.Keywords: nano-silver, titanium, antibacterial activity, silanization method

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-02-24

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

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

  15. Self-Suspended Suspensions of Covalently Grafted Hairy Nanoparticles

    KAUST Repository

    Choudhury, Snehashis

    2015-03-17

    © 2015 American Chemical Society. Dispersions of small particles in liquids have been studied continuously for almost two centuries for their ability to simultaneously advance understanding of physical properties of fluids and their widespread use in applications. In both settings, the suspending (liquid) and suspended (solid) phases are normally distinct and uncoupled on long length and time scales. In this study, we report on the synthesis and physical properties of a novel family of covalently grafted nanoparticles that exist as self-suspended suspensions with high particle loadings. In such suspensions, we find that the grafted polymer chains exhibit unusual multiscale structural transitions and enhanced conformational stability on subnanometer and nanometer length scales. On mesoscopic length scales, the suspensions display exceptional homogeneity and colloidal stability. We attribute this feature to steric repulsions between grafted chains and the space-filling constraint on the tethered chains in the single-component self-suspended materials, which inhibits phase segregation. On macroscopic length scales, the suspensions exist as neat fluids that exhibit soft glassy rheology and, counterintuitively, enhanced elasticity with increasing temperature. This feature is discussed in terms of increased interpenetration of the grafted chains and jamming of the nanoparticles. (Chemical Presented).

  16. Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, Katherine [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    The viscosities of both aqueous and cyanate ester monomer (BECy) based suspensions of alumina nanoparticle were studied. The applications for these suspensions are different: aqueous suspensions of alumina nanoparticles are used in the production of technical ceramics made by slip casting or tape casting, and the BECy based suspensions are being developed for use in an injection-type composite repair resin. In the case of aqueous suspensions, it is advantageous to achieve a high solids content with low viscosity in order to produce a high quality product. The addition of a dispersant is useful so that higher solids content suspensions can be used with lower viscosities. For BECy suspensions, the addition of nanoparticles to the BECy resin is expected to enhance the mechanical properties of the cured composite. The addition of saccharides to aqueous suspensions leads to viscosity reduction. Through DSC measurements it was found that the saccharide molecules formed a solution with water and this resulted in lowering the melting temperature of the free water according to classic freezing point depression. Saccharides also lowered the melting temperature of the bound water, but this followed a different rule. The shear thinning and melting behaviors of the suspensions were used to develop a model based on fractal-type agglomeration. It is believed that the structure of the particle flocs in these suspensions changes with the addition of saccharides which leads to the resultant viscosity decrease. The viscosity of the BECy suspensions increased with solids content, and the viscosity increase was greater than predicted by the classical Einstein equation for dilute suspensions. Instead, the Mooney equation fits the viscosity behavior well from 0-20 vol% solids. The viscosity reduction achieved at high particle loadings by the addition of benzoic acid was also investigated by NMR. It appears that the benzoic acid interacts with the surface of the alumina particle which may

  17. Influence of Alkali Treatment on Anodized Titanium Alloys in Wollastonite Suspension

    Directory of Open Access Journals (Sweden)

    Alicja Kazek-Kęsik

    2017-08-01

    Full Text Available The surface modification of titanium alloys is an effective method to improve their biocompatibility and tailor the material to the desired profile of implant functionality. In this work, technologically-advanced titanium alloys—Ti-15Mo, Ti-13Nb-13Zr and Ti-6Al-7Nb—were anodized in suspensions, followed by treatment in alkali solutions, with wollastonite deposition from the powder phase suspended in solution. The anodized samples were immersed in NaOH or KOH solution with various concentrations with a different set of temperatures and exposure times. Based on their morphologies (observed by scanning electron microscope, the selected samples were investigated by Raman and X-ray photoelectron spectroscopy (XPS. Titaniate compounds were formed on the previously anodized titanium surfaces. The surface wettability significantly decreased, mainly on the modified Ti-15Mo alloy surface. Titanium alloy compounds had an influence on the results of the titanium alloys’ surface modification, which caused the surfaces to exhibit differential physical properties. In this paper, we present the influence of the anodization procedure on alkali treatment effects and the properties of obtained hybrid coatings.

  18. The Promising Features of New Nano Liquid Metals—Liquid Sodium Containing Titanium Nanoparticles (LSnanop

    Directory of Open Access Journals (Sweden)

    Toshio Itami

    2015-07-01

    Full Text Available A new kind of suspension liquid was developed by dispersing Ti nanoparticles (10 nm in liquid Na, which was then determined by TEM (transmission electron microscopy analysis. The volume fraction was estimated to be 0.0088 from the analyzed Ti concentration (2 at. % and the densities of Ti and Na. This suspension liquid, Liquid Sodium containing nanoparticles of titanium (LSnanop, shows, despite only a small addition of Ti nanoparticles, many striking features, namely a negative deviation of 3.9% from the ideal solution for the atomic volume, an increase of 17% in surface tension, a decrease of 11% for the reaction heat to water, and the suppression of chemical reactivity to water and oxygen. The decrease in reaction heat to water seems to be derived from the existence of excess cohesive energy of LSnanop. The excess cohesive energy was discussed based on simple theoretical analyses, with particular emphasis on the screening effect. The suppression of reactivity is discussed with the relation to the decrease of heat of reaction to water or the excess cohesive energy, surface tension, the action as a plug of Ti oxide, negative adsorption on the surface of LSnanop, and percolation.

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

    Science.gov (United States)

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

  20. 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.

  1. Source of cytotoxicity in a colloidal silver nanoparticle suspension.

    Science.gov (United States)

    Hatipoglu, Manolya Kukut; Keleştemur, Seda; Altunbek, Mine; Culha, Mustafa

    2015-05-15

    Silver nanoparticles (AgNPs) are increasingly used in a variety of applications because of their potential antimicrobial activity and their plasmonic and conductivity properties. In this study, we investigated the source of cytotoxicity, genotoxicity, and reactive oxygen species (ROS) production on human dermal fibroblast and human lung cancer (A549) cell lines upon exposure to AgNP colloidal suspensions prepared with the simplest and most commonly used Lee–Meisel method with a variety of reaction times and the concentrations of the reducing agent. The AgNPs synthesized with shorter reaction times were more cytotoxic and genotoxic due to the presence of a few nanometer-sized AgNP seeds. The suspensions prepared with an increased citrate concentration were not cytotoxic, but they induced more ROS generation on A549 cells due to the high citrate concentration. The genotoxicity of the suspension decreased significantly at the higher citrate concentrations. The analysis of both transmission electron microscopy images from the dried droplet areas of the colloidal suspensions and toxicity data indicated that the AgNP seeds were the major source of toxicity. The completion of the nucleation step and the formation of larger AgNPs effectively decreased the toxicity.

  2. Capillary interactions in nano-particle suspensions

    International Nuclear Information System (INIS)

    Bossev, D.P.; Warren, G.

    2009-01-01

    We have investigated the structures formed by colloidal particles suspended in solvents at volume fractions below 10% and interacting through capillary bridges. Such systems resemble colloidal gas of sticky nano-spheres that form pearl-necklace like chains that, in turn, induce strong viscoelasticity due to the formation of 3-D fractal network. The capillary force dominates the electrostatic and Van der Waals forces in solutions and can bridge multiple particles depending of the volume of the capillary bridge. We have investigated the morphology of the structures formed at different fractions of the bridging fluid. Small-angle neutron scattering (SANS) is used to study nanoparticles with an average diameter of 10 nm in polar and non-polar organic solvents at ambient temperatures. SANS intensity as a function of the scattering vector is analyzed as a product of a form factor, that depends on the particle shape, and a structure factor, that characterizes the interparticle inter reactions. The interaction of particles in polar solvents is considered to be through electrostatic repulsion and the data is successfully fitted by Hayter-Penfold mean spherical approximation (HPMSA). Computer simulations of a pearl necklace-like chain of spheres is conducted to explain the structure factor when capillary bridges are present. Alternatively, we have analyzed the slope of the intensity at low scattering vector in a double logarithmic plot to determine the dimension of the fractal structures formed by the particles at different volume fraction of the bridging fluid. We have also studied the properties of the capillary bridge between a pair of particles. The significance of this study is to explore the possibility of using capillary force as a tool to engineer new colloidal structures and materials in solutions and to optimize their viscoelastic properties. (author)

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

    OpenAIRE

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Bazhenov Yuriy Mikhaylovich

    2012-10-01

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

  5. Shear thickening behavior of nanoparticle suspensions with carbon nanofillers

    Energy Technology Data Exchange (ETDEWEB)

    Sha, Xiaofei; Yu, Kejing, E-mail: yukejing@gmail.com; Cao, Haijian; Qian, Kun [Ministry of Education, Jiangnan University, Key Laboratory of Eco-textiles (China)

    2013-07-15

    Suspensions comprised of silica nanoparticle (average diameter: 650 nm) and carbon nanofillers dispersed in polyethylene glycol were prepared and investigated. Rheological measurement demonstrated that the mixed suspensions showed a non-Newtonian flow profile, and the shear thickening effect was enhanced by the addition of carbon nanotubes (CNTs) (main range of diameter: 10-20 nm; length: 5-15 {mu}m; purity: >97 wt%) and graphene nanoplatelets (GNs) (average diameter: >50 nm; average length: 20 {mu}m; purity: >92 wt%). It suggested that better the aggregation effect of dispersed particles was, the more significant the shear thickening effect achieved. The results also revealed that the formation of large nanomaterials clusters could be suitable to explain the phenomena. Furthermore, the trend of shear thickening behavior of the silica suspension with CNTs was more striking than that of GNs. The physical reactions between those multi-dispersed phases had been described by the schematic illustrations in papers. Otherwise, a model was built to explain these behaviors, which could be attributed to the unique structures and inherent properties of these two different nanofillers. And the morphologies of the shear thickening fluid which were examined by transmission electron microscopy confirmed this mechanism.

  6. A comparison between acoustic properties and heat effects in biogenic (magnetosomes) and abiotic magnetite nanoparticle suspensions

    International Nuclear Information System (INIS)

    Józefczak, A.; Leszczyński, B.; Skumiel, A.; Hornowski, T.

    2016-01-01

    Magnetic nanoparticles show unique properties and find many applications because of the possibility to control their properties using magnetic field. Magnetic nanoparticles are usually synthesized chemically and modification of the particle surface is necessary. Another source of magnetic nanoparticles are various magnetotactic bacteria. These biogenic nanoparticles (magnetosomes) represent an attractive alternative to chemically synthesized iron oxide particles because of their unique characteristics and a high potential for biotechnological and biomedical applications. This work presents a comparison between acoustic properties of biogenic and abiotic magnetite nanoparticle suspensions. Experimental studies have shown the influence of a biological membrane on the ultrasound properties of magnetosomes suspension. Finally the heat effect in synthetic and biogenic magnetite nanoparticles is also discussed. The experimental study shows that magnetosomes present good heating efficiency. - Highlights: • A biogenic and abiotic magnetite nanoparticle suspensions are investigated. • A comparison between ultrasonic properties and heat effects is presented. • Magnetosomes and abiotic magnetite nanoparticles exhibit good heating efficiency.

  7. Recent Developments in Suspension Plasma Sprayed Titanium Oxide and Hydroxyapatite Coatings

    Science.gov (United States)

    Jaworski, R.; Pawlowski, L.; Pierlot, C.; Roudet, F.; Kozerski, S.; Petit, F.

    2010-01-01

    The paper aims at reviewing of the recent studies related to the development of suspension plasma sprayed TiO2 and Ca5(PO4)3OH (hydroxyapatite, HA) coatings as well as their multilayer composites obtained onto stainless steel, titanium and aluminum substrates. The total thickness of the coatings was in the range 10 to 150 μm. The suspensions on the base of distilled water, ethanol and their mixtures were formulated with the use of fine commercial TiO2 pigment crystallized as rutile and HA milled from commercial spray-dried powder or synthesized from calcium nitrate and ammonium phosphate in an optimized reaction. The powder was crystallized as hydroxyapatite. Pneumatic and peristaltic pump liquid feeders were applied. The injection of suspension to the plasma jet was studied carefully with the use of an atomizer injector or a continuous stream one. The injectors were placed outside or inside of the anode-nozzle of the SG-100 plasma torch. The stream of liquid was tested under angle right or slightly backwards with regard to the torch axis. The sprayed deposits were submitted to the phase analysis by the use of x-ray diffraction. The content of anatase and rutile was calculated in the titanium oxide deposits as well as the content of the decomposition phases in the hydroxyapatite ones. The micro-Raman spectroscopy was used to visualize the area of appearance of some phases. Scratch test enabled to characterize the adhesion of the deposits, their microhardness and friction coefficient. The electric properties including electron emission, impedance spectroscopy, and dielectric properties of some coatings were equally tested.

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

    Directory of Open Access Journals (Sweden)

    Matteo Crosera

    2015-08-01

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

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

    Science.gov (United States)

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

    2015-08-07

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

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

    OpenAIRE

    Naofumi Uekawa; Naoya Endo; Keisuke Ishii; Takashi Kojima; Kazuyuki Kakegawa

    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 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...

  11. The structure and properties of fluoroplastic modified with titanium nanoparticles

    Science.gov (United States)

    Baronin, G. S.; Buznik, V. M.; Dmitriev, O. S.; Zavrazhina, C. V.; Mishchenko, S. V.; Zavrazhin, D. O.; Khudyakov, V. V.

    2017-12-01

    The results of studying the structure and properties of a mixture of polytetrafluoroethylene (PTFE) and fillers, which are composites of ultrafine polytetrafluoroethylene and titanium (TiFP) nanoparticles, are presented. These composites are obtained with pyrolytic redistribution of a powdered PTFE - (NH4)2TiF6 mixture. It has been found that the composite properties depend on the type and concentration of the inorganic filler and the composite production technology. The created composites exceed the original PTFE in a number of characteristics (deflection temperature, thermal conductivity and durability).

  12. Effect of Chemical Stabilizers in Silver Nanoparticle Suspensions on Nanotoxicity

    International Nuclear Information System (INIS)

    Bae, Eun Joo; Park, Hee Jin; Park, Jun Su; Yoon, Je Yong; Yi, Jong Heop; Kim, Young Hun; Choi, Kyung Hee

    2011-01-01

    Colloidal silver nanoparticles (AgNPs) have been commercialized as the typically stabilized form via the addition of a variety of surfactants or polymers. Herein, to examine the effects of stabilizing AgNPs in suspension, we modified the surface of bare AgNPs with four type of surfactants (NaDDBS, SDS, TW80, CTAB) and polymers (PVP, PAA, PAH, CMC). The modified AgNPs was applied to compare suspension stability and nanotoxicity test using Escherichia coli (E. coli) as a model organism. Modification of AgNPs surface using chemical stabilizer may be not related with molecular weight, but chemical structure such as ionic state and functional group of stabilizer. In this study, it is noteworthy that AgNPs modified with a cationic stabilizer (CTAB, PAH) were importantly toxic to E. coli, rather than anionic stabilizers (NaDDBS, SDS). Comparing similar anionic stabilizer, i.e., NaDDBS and SDS, the result showed that lipophilicity of chemical structure can affect on E. coli, because NaDDBS, which contains a lipophilic benzene ring, accelerated the cytotoxicity of AgNPs. Interestingly, none of the stabilizers tested, including biocompatible nonionic stabilizers (i.e., TW80 and cellulose) caused a reduction in AgNP toxicity. This showed that toxicity of AgNPs cannot be reduced using stabilizers

  13. Effect of Chemical Stabilizers in Silver Nanoparticle Suspensions on Nanotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Eun Joo; Park, Hee Jin; Park, Jun Su; Yoon, Je Yong; Yi, Jong Heop [Seoul National University, Seoul (Korea, Republic of); Kim, Young Hun [Kwangwoon University, Seoul (Korea, Republic of); Choi, Kyung Hee [National Institute of Environmental Research, Incheon (Korea, Republic of)

    2011-02-15

    Colloidal silver nanoparticles (AgNPs) have been commercialized as the typically stabilized form via the addition of a variety of surfactants or polymers. Herein, to examine the effects of stabilizing AgNPs in suspension, we modified the surface of bare AgNPs with four type of surfactants (NaDDBS, SDS, TW80, CTAB) and polymers (PVP, PAA, PAH, CMC). The modified AgNPs was applied to compare suspension stability and nanotoxicity test using Escherichia coli (E. coli) as a model organism. Modification of AgNPs surface using chemical stabilizer may be not related with molecular weight, but chemical structure such as ionic state and functional group of stabilizer. In this study, it is noteworthy that AgNPs modified with a cationic stabilizer (CTAB, PAH) were importantly toxic to E. coli, rather than anionic stabilizers (NaDDBS, SDS). Comparing similar anionic stabilizer, i.e., NaDDBS and SDS, the result showed that lipophilicity of chemical structure can affect on E. coli, because NaDDBS, which contains a lipophilic benzene ring, accelerated the cytotoxicity of AgNPs. Interestingly, none of the stabilizers tested, including biocompatible nonionic stabilizers (i.e., TW80 and cellulose) caused a reduction in AgNP toxicity. This showed that toxicity of AgNPs cannot be reduced using stabilizers.

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

    Science.gov (United States)

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

  15. Solid lipid nanoparticles suspension versus commercial solutions for dermal delivery of minoxidil.

    Science.gov (United States)

    Padois, Karine; Cantiéni, Céline; Bertholle, Valérie; Bardel, Claire; Pirot, Fabrice; Falson, Françoise

    2011-09-15

    Solid lipid nanoparticles have been reported as possible carrier for skin drug delivery. Solid lipid nanoparticles are produced from biocompatible and biodegradable lipids. Solid lipid nanoparticles made of semi-synthetic triglycerides stabilized with a mixture of polysorbate and sorbitan oleate were loaded with 5% of minoxidil. The prepared systems were characterized for particle size, pH and drug content. Ex vivo skin penetration studies were performed using Franz-type glass diffusion cells and pig ear skin. Ex vivo skin corrosion studies were realized with a method derived from the Corrositex(®) test. Solid lipid nanoparticles suspensions were compared to commercial solutions in terms of skin penetration and skin corrosion. Solid lipid nanoparticles suspensions have been shown as efficient as commercial solutions for skin penetration; and were non-corrosive while commercial solutions presented a corrosive potential. Solid lipid nanoparticles suspensions would constitute a promising formulation for hair loss treatment. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Preparation and evaluation of tilmicosin-loaded hydrogenated castor oil nanoparticle suspensions of different particle sizes.

    Science.gov (United States)

    Chen, Xiaojin; Wang, Ting; Lu, Mengmeng; Zhu, Luyan; Wang, Yan; Zhou, WenZhong

    2014-01-01

    Three tilmicosin-loaded hydrogenated castor oil nanoparticle (TMS-HCO-NP) suspensions of different particle sizes were prepared with different polyvinyl alcohol surfactant concentrations using a hot homogenization and ultrasonic technique. The in vitro release, in vitro antibacterial activity, mammalian cytotoxicity, acute toxicity in mice, and stability study were conducted to evaluate the characteristics of the suspensions. The in vitro tilmicosin release rate, antibacterial activity, mammalian cytotoxicity, acute toxicity in mice, and stability of the suspensions were evaluated. When prepared with polyvinyl alcohol concentrations of 0.2%, 1%, and 5%, the mean diameters of the nanoparticles in the three suspensions were 920±35 nm, 452±10 nm, and 151±4 nm, respectively. The three suspensions displayed biphasic release profiles similar to that of freeze-dried TMS-HCO-NP powders, with the exception of having a faster initial release. Moreover, suspensions of smaller-sized particles showed faster initial release, and lower minimum inhibitory concentrations and minimum bactericidal concentrations. Time-kill curves showed that within 12 hours, the suspension with the 151 nm particles had the most potent bactericidal activity, but later, the suspensions with larger-sized particles showed increased antibacterial activity. None of the three suspensions were cytotoxic at clinical dosage levels. At higher drug concentrations, all three suspensions showed similar concentration-dependent cytotoxicity. The suspension with the smallest-sized particle showed significantly more acute toxicity in mice, perhaps due to faster drug release. All three suspensions exhibited good stability at 4°C and at room temperature for at least 6 months. These results demonstrate that TMS-HCO-NP suspensions can be a promising formulation for tilmicosin, and that nanoparticle size can be an important consideration for formulation development.

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

    Science.gov (United States)

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

    2014-07-01

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

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

    Science.gov (United States)

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

    2016-03-29

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

  19. 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.

  20. Synthesis of titanium oxide nanoparticles using DNA-complex as template for solution-processable hybrid dielectric composites

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, J.C. [Center for Sustainable Materials Chemistry, 153 Gilbert Hall, Oregon State University, Corvallis, OR (United States); Mejia, I.; Murphy, J.; Quevedo, M. [Department of Materials Science and Engineering, University of Texas at Dallas, Dallas, TX (United States); Garcia, P.; Martinez, C.A. [Engineering and Technology Institute, Autonomous University of Ciudad Juarez, Ciudad Juarez, Chihuahua (Mexico)

    2015-09-15

    Highlights: • We developed a synthesis method to produce TiO{sub 2} nanoparticles using a DNA complex. • The nanoparticles were anatase phase (~6 nm diameter), and stable in alcohols. • Composites showed a k of 13.4, 4.6 times larger than the k of polycarbonate. • Maximum processing temperature was 90 °C. • Low temperature enables their use in low-voltage, low-cost, flexible electronics. - Abstract: We report the synthesis of TiO{sub 2} nanoparticles prepared by the hydrolysis of titanium isopropoxide (TTIP) in the presence of a DNA complex for solution processable dielectric composites. The nanoparticles were incorporated as fillers in polycarbonate at low concentrations (1.5, 5 and 7 wt%) to produce hybrid dielectric films with dielectric constant higher than thermally grown silicon oxide. It was found that the DNA complex plays an important role as capping agent in the formation and suspension stability of nanocrystalline anatase phase TiO{sub 2} at room temperature with uniform size (∼6 nm) and narrow distribution. The effective dielectric constant of spin-cast polycarbonate thin-films increased from 2.84 to 13.43 with the incorporation of TiO{sub 2} nanoparticles into the polymer host. These composites can be solution processed with a maximum temperature of 90 °C and could be potential candidates for its application in low-cost macro-electronics.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-15

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-06

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  5. Turkevich method for silver/titanium dioxide nanoparticles with antimicrobial application in polymers systems;Obtencao de nanoparticulas de prata/dioxido de titanio pelo metodo Turkevich para aplicacoes antimicrobiais em matrizes polimericas

    Energy Technology Data Exchange (ETDEWEB)

    Olyveira, Gabriel Molina de; Pessan, Luiz Antonio, E-mail: gmolyveira@yahoo.com.b, E-mail: acarvalho@ufscar.b [Universidade Federal de Sao Carlos (PPG-CEM/UFSCar), SP (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Carvalho, Antonio Jose Felix de [Universidade Federal de Sao Carlos (UFSCar), Sorocaba, SP (Brazil)

    2009-07-01

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

  6. Nanobiotechnology approach to fabricate polycaprolactone nanofibers containing solid titanium nanoparticles as future implant materials

    DEFF Research Database (Denmark)

    Sheikh, Faheem A.; Kanjwal, Muzafar Ahmed; Cha, Jaegwan

    2011-01-01

    In this study, a good combination of electrospun poly(caprolactone) nanofibers incorporated with high purity titanium nanoparticles is introduced for hard tissue engineering applications. A simple approach to utilize the colloidal properties of poly(caprolactone) and titanium nanoparticles...... nanofiber mats, they were incubated in simulated body fluid at 37 °C for 10 days. Field emission scanning electron microscopy in combination with energy-dispersive X-ray spectroscopy indicated that incorporation of titanium strongly activates precipitation of the apatite-like materials from the utilized...... simulated body fluid. Moreover, in-vivo experiments using experimental dogs revealed that nanofibers can yield good tissue regeneration on the surfaces of nanofibers....

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

    Science.gov (United States)

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

    2018-06-01

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

  8. Experimental and numerical study on the optical properties and agglomeration of nanoparticle suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Otanicar, Todd, E-mail: todd-otanicar@utulsa.edu; Hoyt, Jordan; Fahar, Maryam [University of Tulsa, Department of Mechanical Engineering (United States); Jiang, Xuchuan [University of New South Wales, School of Materials Science and Engineering (Australia); Taylor, Robert A. [University of New South Wales, School of Mechanical and Manufacturing Engineering (Australia)

    2013-11-15

    Nanoparticles have garnered significant interest because of their ability to enhance greatly the optical properties of the base fluid in which they are suspended. The optical properties of nanoparticles are sensitive to the materials used, as well as to the host medium. Most fluids exhibit refractive indices that are highly temperature-dependent, resulting in nanoparticle suspensions which also exhibit temperature-dependent optical properties. Previous work has shown that temperature increases result in decreased absorption in nanoparticle suspensions. Here, we expand previous work to include core–shell particles due to the potential spectral shifts in optical properties that will arise from the base fluid with temperature changes and the role of agglomeration under temperature cycling through both experimental and numerical efforts. Thermal cycling tests for silica and gold, the constituents of the core–shell nanoparticles used in this study, were tested to determine the extent of particle agglomeration resulting from up to 200 accelerated heating cycles. Optical properties were recorded after heating two base fluids (water and ethylene glycol) with multiple surfactants for silver nanospheres and silica–gold core–shell nanoparticles. It was found that the temperature results in a small increase in the transmittance for both particle types and a blue shift in the spectral transmittance for core–shell nanoparticles. Further, the coupling effect of temperature and agglomeration played a significant role in determining both the spectral properties—particularly the resulting transmittance—of the silver nanoparticle suspensions.

  9. The Effect of pH and Time on The Stability of Superparamagnetic Maghemite Nanoparticle Suspensions

    Directory of Open Access Journals (Sweden)

    Nurdin Irwan

    2016-01-01

    Full Text Available Maghemite (γ-Fe2O3 nanoparticles have been synthesized using a chemical co-precipitation method. The morphology and particle size is characterized using Transmission Electron Microscopy (TEM, and magnetic characterization using Alternating Gradient Magnetometry (AGM. The stability of the maghemite nanoparticles suspension were studied at different pH and time of storage. Dynamic Light Scattering (DLS and Zeta Potential were conducted to determine the stability of the suspensions. TEM observation showed that the particles size is 9.6 nm and have spherical morphology. The particles showed superparamagnetic behavior with saturation magnetization 25.5 emu/g. The suspensions are stable in the acidic condition at pH 4 and alkaline condition at pH 10. The suspensions remain stable after 4 weeks of storage.

  10. Degradability of aged aquatic suspensions of C60 nanoparticles

    DEFF Research Database (Denmark)

    Hartmann, Nanna Isabella Bloch; Buendia, Inmaculada M.; Bak, Jimmy

    2011-01-01

    In this study, aged aqueous suspensions of C(60) (nC(60)) were investigated in the respirometric OECD test for ready biodegradability. Two suspensions of nC(60) were prepared by stirring and aged under indirect exposure to sunlight for 36 months. ATR-FTIR analyses confirmed the presence of C(60)-...

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

    Science.gov (United States)

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

  12. Interparticle potential of 10 nanometer titanium nanoparticles in liquid sodium: Theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soo Jae; Park, Gun Yeop; Park, Hyun Sun; Baek, Je Hyun [POSTECH, Pohang (Korea, Republic of); Kim, Moo Hwan [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    A suspension of titanium nanoparticles (Ti NPs) in liquid sodium (Na) has been proposed as a method to mitigate the violent sodium-water reaction (SWR). The interparticle potential between Ti NPs in liquid Na may play a significant role in the agglomeration of NPs on the reaction surface and in the bulk liquid Na, since the potential contributes to a reduction in the long-term dispersion stability. For the effective control of the SWR with NPs, a physical understanding of the molecular dynamics of NPs in liquid Na is key. Therefore in this study, the nonretarded Van der Waals model and the solvation potential model are employed to analyze the interparticle potential. The ab initio calculation reveals that a strong repulsive force driven by the solvation potential exceeds the interparticle attraction and predicts the agglomeration energy required for two 10-nm Ti NPs to be 4 x 10{sup -17} J. The collision theory suggests that Ti NPs can be effective suppressors of the SWR due to the high energy barrier that prevents significant agglomeration of Ti NPs in quiescent liquid Na.

  13. Pyrolytic carbon coating for cytocompatibility of titanium oxide nanoparticles: a promising candidate for medical applications

    International Nuclear Information System (INIS)

    Behzadi, Shahed; Simchi, Abdolreza; Imani, Mohammad; Yousefi, Mohammad; Galinetto, Pietro; Amiri, Houshang; Stroeve, Pieter; Mahmoudi, Morteza

    2012-01-01

    Nanoparticles for biomedical use must be cytocompatible with the biological environment that they are exposed to. Current research has focused on the surface functionalization of nanoparticles by using proteins, polymers, thiols and other organic compounds. Here we show that inorganic nanoparticles such as titanium oxide can be coated by pyrolytic carbon (PyC) and that the coating has cytocompatible properties. Pyrolization and condensation of methane formed a thin layer of pyrolytic carbon on the titanium oxide core. The formation of the PyC shell retards coalescence and sintering of the ceramic phase. Our MTT assay shows that the PyC-coated particles are cytocompatible at employed doses. (paper)

  14. Titanium

    DEFF Research Database (Denmark)

    Fage, Simon W; Muris, Joris; Jakobsen, Stig S

    2016-01-01

    Exposure to titanium (Ti) from implants and from personal care products as nanoparticles (NPs) is common. This article reviews exposure sources, ion release, skin penetration, allergenic effects, and diagnostic possibilities. We conclude that human exposure to Ti mainly derives from dental...... and medical implants, personal care products, and foods. Despite being considered to be highly biocompatible relative to other metals, Ti is released in the presence of biological fluids and tissue, especially under certain circumstances, which seem to be more likely with regard to dental implants. Although...... most of the studies reviewed have important limitations, Ti seems not to penetrate a competent skin barrier, either as pure Ti, alloy, or as Ti oxide NPs. However, there are some indications of Ti penetration through the oral mucosa. We conclude that patch testing with the available Ti preparations...

  15. Effects of titanium dioxide nanoparticles on human keratinocytes.

    Science.gov (United States)

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

    2017-01-01

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

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

    International Nuclear Information System (INIS)

    Zhang Hui; Yang Lu

    2012-01-01

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

  17. Partitioning and Dissolution Behavior of Metal-based Engineered Nanoparticles in Sediment and Soil Suspensions

    Directory of Open Access Journals (Sweden)

    Koetsem F. Van

    2013-04-01

    Full Text Available Nowadays engineered nanoparticles are being used in a whole range of commercial applications and are therefore expected to inevitably find their way into the environment where their fate and behavior are still largely unknown. The objective of this study was to investigate the behavior and fate of a number of engineered nanoparticles (CeO2, SnO2, Ag in sediment and soil suspensions. In particular, the association of nanoparticles with solid phases, the kinetics of these interactions, and the solubility of the nanoparticulate matter in sediment and soil suspensions were studied. Four different sediments and three different soils were sampled at various locations in Flanders (Belgium, dried, grinded and characterized. Sediment and soil suspensions were prepared with Milli-Q water (1/10 S/L, spiked with the different metallic nanoparticles or corresponding ions, and continuously shaken for 24 hours. At regular time intervals, samples of the suspensions were collected and centrifuged at 500 or 2000 rpm, or left for gravitational settling. The supernatant was analyzed for total metal contents after aqua regia digestion and for dissolved metal ions after centrifugal ultrafiltration. In a second experiment, the impact of centrifugation speed on the amount of suspended matter in the supernatant was also studied. Relations between soil or sediment properties, suspended matter and metals in the supernatant were investigated. First data already point towards a strong association of nanoparticles with suspended material. The remaining data are still being collected and will be presented at the conference.

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

    Science.gov (United States)

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

    2016-11-29

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

  19. Degradability of aged aquatic suspensions of C60 nanoparticles

    DEFF Research Database (Denmark)

    Hartmann, B.; Buendia, Inmaculada M.; Baun, Anders

    2011-01-01

    While studies of the potential human and environmental effects of C60 and its derivatives are emerging in the scientific literature, the environmental fate of C60 is still largely unknown. In this study, aged aqueous suspensions of C60 (nC60) were investigated in the respirometric OECD test...... for ready biodegradability. Two suspensions of nC60 were prepared by stirring and aged under indirect exposure to sunlight for 36 months, which resulted in relatively stable suspensions with a dark-brown colour. The suspended nC60 could not be extracted into toluene and indicating that the particles were...... no longer present as underivatised nC60 but had undergone a transformation. TEM images and particle tracking analysis showed that the suspension consisted of particle aggregates with a size of 156 nm (SD=54nm) and 139nm (Sd=49), respectively, but also contained smaller aggregates. Samples of the nC60...

  20. Self-Suspended Suspensions of Covalently Grafted Hairy Nanoparticles

    KAUST Repository

    Choudhury, Snehashis; Agrawal, Akanksha; Kim, Sung A; Archer, Lynden A.

    2015-01-01

    length scales. On mesoscopic length scales, the suspensions display exceptional homogeneity and colloidal stability. We attribute this feature to steric repulsions between grafted chains and the space-filling constraint on the tethered chains

  1. An improved experimental methodology to evaluate the effectiveness of protective gloves against nanoparticles in suspension.

    Science.gov (United States)

    Vinches, Ludwig; Zemzem, Mohamed; Hallé, Stéphane; Peyro, Caroline; Wilkinson, Kevin J; Tufenkji, Nathalie

    2017-07-01

    Recent studies underline the potential health risks associated to the "nano" revolution, particularly for the workers who handle engineered nanoparticles (ENPs) that can be found in the formulation of several commercial products. Although many Health & Safety agencies recommend the use of protective gloves against chemicals, few studies have investigated the effectiveness of these gloves towards nanoparticle suspensions. Moreover, the data that are available are often contradictory. This study was designed to evaluate the effectiveness of protective gloves against nanoparticles in suspension. For this purpose, a new methodology was developed in order to take into account parameters encountered in the workplace such as mechanical deformations (MD) that simulate hand flexion and sweat. The effects of the precise experimental protocol on the concentrations of nanoparticles that were detected in the sampling suspension were assessed. Several samples of nitrile rubber gloves (73 µm thick), taken from different boxes, were brought into contact with gold nanoparticles (5 nm) in water. During their exposure to ENPs, the glove samples submitted systematic mechanical deformations and were placed in contact with a physiological solution simulating human sweat. Under these conditions, results obtained by inductively coupled plasma mass spectrometry (ICPMS) showed that the 5 nm gold nanoparticles passed through the protective gloves. This result was acquired, in spite of the observation of significant losses during the sampling phase that will be important for future experiments evaluating the effectiveness of these materials.

  2. Nitroxide-Mediated Radical Polymerization of Styrene Initiated from the Surface of Titanium Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Abbasian

    2016-01-01

    Full Text Available Titanium dioxide (TiO2 nanoparticles, with an average size of about 45 nm, were encapsulated by polystyrene using in situ nitroxide mediated radical polymerization   in the presence of 3-aminopropyl triethoxy silane (APTES as a coupling agent and 2, 2, 6, 6-tetramethylpiperidinyl-1-oxy  as a initiator. First, the initiator for NMRP was covalently bonded onto the surface of Titanium dioxide nanoparticles through our novel method. For this purpose, the surface of TiO2 nanoparticle was treated with 3-aminopropyl triethoxy silane, a silane coupling agent, and then these functionalized nanoparticles was reacted with ±-chloro phenyl acetyl chloride. The chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2, 2, 6, 6-tetramethyl piperidine. These modified TiO2 nanoparticles were then dispersed in styrene (St monomers to carry out the in situ free radical polymerization.

  3. Rheological and electrical properties of polymeric nanoparticle solutions and their influence on RBC suspensions

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Koseva, N.; Kowalczyk, A.; Říha, Pavel; Ivanov, I.

    2014-01-01

    Roč. 24, č. 3 (2014), s. 35190 ISSN 1430-6395 Institutional support: RVO:67985874 Keywords : nanoparticles and RBC suspensions * poly(acrylic acid) * rheology * electrical conductivity Subject RIV: BK - Fluid Dynamics Impact factor: 1.078, year: 2014 http://www.ar.ethz.ch/TMPPDF/24308140293.696/ApplRheol_24_35190.pdf

  4. Effects of Atomization Injection on Nanoparticle Processing in Suspension Plasma Spray

    Directory of Open Access Journals (Sweden)

    Hong-bing Xiong

    2016-05-01

    Full Text Available Liquid atomization is applied in nanostructure dense coating technology to inject suspended nano-size powder materials into a suspension plasma spray (SPS torch. This paper presents the effects of the atomization parameters on the nanoparticle processing. A numerical model was developed to simulate the dynamic behaviors of the suspension droplets, the solid nanoparticles or agglomerates, as well as the interactions between them and the plasma gas. The plasma gas was calculated as compressible, multi-component, turbulent jet flow in Eulerian scheme. The droplets and the solid particles were calculated as discrete Lagrangian entities, being tracked through the spray process. The motion and thermal histories of the particles were given in this paper and their release and melting status were observed. The key parameters of atomization, including droplet size, injection angle and velocity were also analyzed. The study revealed that the nanoparticle processing in SPS preferred small droplets with better atomization and less aggregation from suspension preparation. The injection angle and velocity influenced the nanoparticle release percentage. Small angle and low initial velocity might have more nanoparticles released. Besides, the melting percentage of nanoparticles and agglomerates were studied, and the critical droplet diameter to ensure solid melting was drawn. Results showed that most released nanoparticles were well melted, but the agglomerates might be totally melted, partially melted, or even not melted at all, mainly depending on the agglomerate size. For better coating quality, the suspension droplet size should be limited to a critical droplet diameter, which was inversely proportional to the cubic root of weight content, for given critical agglomerate diameter of being totally melted.

  5. Titanium

    Science.gov (United States)

    Woodruff, Laurel G.; Bedinger, George M.; Piatak, Nadine M.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Titanium is a mineral commodity that is essential to the smooth functioning of modern industrial economies. Most of the titanium produced is refined into titanium dioxide, which has a high refractive index and is thus able to impart a durable white color to paint, paper, plastic, rubber, and wallboard. Because of their high strength-to-weight ratio and corrosion resistance, titanium metal and titanium metal alloys are used in the aerospace industry as well as for welding rod coatings, biological implants, and consumer goods.Ilmenite and rutile are currently the principal titanium-bearing ore minerals, although other minerals, including anatase, perovskite, and titanomagnetite, could have economic importance in the future. Ilmenite is currently being mined from two large magmatic deposits hosted in rocks of Proterozoic-age anorthosite plutonic suites. Most rutile and nearly one-half of the ilmenite produced are from heavy-mineral alluvial, fluvial, and eolian deposits. Titanium-bearing minerals occur in diverse geologic settings, but many of the known deposits are currently subeconomic for titanium because of complications related to the mineralogy or because of the presence of trace contaminants that can compromise the pigment production process.Global production of titanium minerals is currently dominated by Australia, Canada, Norway, and South Africa; additional amounts are produced in Brazil, India, Madagascar, Mozambique, Sierra Leone, and Sri Lanka. The United States accounts for about 4 percent of the total world production of titanium minerals and is heavily dependent on imports of titanium mineral concentrates to meet its domestic needs.Titanium occurs only in silicate or oxide minerals and never in sulfide minerals. Environmental considerations for titanium mining are related to waste rock disposal and the impact of trace constituents on water quality. Because titanium is generally inert in the environment, human health risks from titanium and titanium

  6. A review on potential neurotoxicity of titanium dioxide nanoparticles

    Science.gov (United States)

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

    2015-08-01

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

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

    Science.gov (United States)

    2013-01-01

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

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

    Science.gov (United States)

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

    2013-04-15

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

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

    Directory of Open Access Journals (Sweden)

    Jiaying Xu

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

  10. NMR relaxometric properties and cytotoxicity of Gd2O3 nanoparticle suspensions in an organic liquid

    Science.gov (United States)

    Babić-Stojić, Branka; Jokanović, Vukoman; Milivojević, Dušan; Požek, Miroslav; Jagličić, Zvonko; Makovec, Darko; Arsikin, Katarina; Paunović, Verica

    2014-10-01

    Gd2O3 nanoparticles and their agglomerates from approximately 10 to 80 nm in size suspended in an organic liquid were synthesized via polyol route. The reaction between diethylene glycol and added acetic acid, which occurred simultaneously with the synthesis of Gd2O3 nanoparticles, was catalyzed by sodium bisulfate to transform as much as possible diethylene glycol in corresponding ester at the end of complete reaction. The produced nanosized material of gadolinium oxide was investigated by TEM, DLS, FTIR spectroscopy, and NMR relaxometry. Biological evaluation of this material was done by MTT and crystal violet assays to determine the cell viability. Longitudinal and transverse relaxivities of water-diluted Gd2O3 nanoparticle suspensions estimated to be r 1 = 13.6 and r 2 = 14.7 s-1 mM-1 are about three times higher compared to the relaxivities obtained for standard contrast agent Gd-DTPA (Magnevist). Good MRI signal intensities of the water-diluted Gd2O3 nanoparticle suspensions were recorded in the Gd concentration range 0.2-0.3 mM for which the suspensions were not toxic exhibiting simultaneously higher signal intensities than those for Magnevist in the Gd concentration range 0.4-1 mM for which this standard contrast agent was not toxic. These properties make the produced Gd2O3 nanoparticle material promising for potential application as MRI contrast agent.

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

    Science.gov (United States)

    Tanabe, Ichiro; Kurawaki, Yuji

    2018-05-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Donya Ramimoghadam

    2014-01-01

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

  14. Solid lipid nanoparticle suspension enhanced the therapeutic efficacy of praziquantel against tapeworm

    Directory of Open Access Journals (Sweden)

    Xie S

    2011-10-01

    Full Text Available Shuyu Xie1,*, Baoliang Pan1,*, Baoxin Shi2, Zhuangzhi Zhang2, Xu Zhang2, Ming Wang1, Wenzhong Zhou11Department of Preventive Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China; 2Veterinary Research Institute, Xinjiang Academy of Animal Science, Xinjiang, People’s Republic of China *These authors contributed equally to this study Abstract: Hydatid disease caused by tapeworm is an increasing public health and socioeconomic concern. In order to enhance the therapeutic efficacy of praziquantel (PZQ against tapeworm, PZQ-loaded hydrogenated castor oil solid lipid nanoparticle (PZQ-HCO-SLN suspension was prepared by a hot homogenization and ultrasonication method. The stability of the suspension at 4°C and room temperature was evaluated by the physicochemical characteristics of the nanoparticles and in-vitro release pattern of the suspension. Pharmacokinetics was studied after subcutaneous administration of the suspension in dogs. The therapeutic effect of the novel formulation was evaluated in dogs naturally infected with Echinococcus granulosus. The results showed that the drug recovery of the suspension was 97.59% ± 7.56%. Nanoparticle diameter, polydispersivity index, and zeta potential were 263.00 ± 11.15 nm, 0.34 ± 0.06, and -11.57 ± 1.12 mV, respectively and showed no significant changes after 4 months of storage at both 4°C and room temperature. The stored suspensions displayed similar in-vitro release patterns as that of the newly prepared one. SLNs increased the bioavailability of PZQ 5.67-fold and extended the mean residence time of the drug from 56.71 to 280.38 hours. Single subcutaneous administration of PZQ-HCO-SLN suspension obtained enhanced therapeutic efficacy against tapeworm in infected dogs. At the dose of 5 mg/kg, the stool-ova reduction and negative conversion rates and tapeworm removal rate of the suspension were 100%, while the native PZQ were 91

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

    Science.gov (United States)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  17. Plasma synthesis of titanium nitride, carbide and carbonitride nanoparticles by means of reactive anodic arc evaporation from solid titanium

    International Nuclear Information System (INIS)

    Kiesler, D.; Bastuck, T.; Theissmann, R.; Kruis, F. E.

    2015-01-01

    Plasma methods using the direct evaporation of a transition metal are well suited for the cost-efficient production of ceramic nanoparticles. In this paper, we report on the development of a simple setup for the production of titanium-ceramics by reactive anodic arc evaporation and the characterization of the aerosol as well as the nanopowder. It is the first report on TiC X N 1 − X synthesis in a simple anodic arc plasma. By means of extensive variations of the gas composition, it is shown that the composition of the particles can be tuned from titanium nitride over a titanium carbonitride phase (TiC X N 1 − X ) to titanium carbide as proven by XRD data. The composition of the plasma gas especially a very low concentration of hydrocarbons around 0.2 % of the total plasma gas is crucial to tune the composition and to avoid the formation of free carbon. Examination of the particles by HR-TEM shows that the material consists mostly of cubic single crystalline particles with mean sizes between 8 and 27 nm

  18. Stability of titania nanoparticles in soil suspensions and transport in saturated homogeneous soil columns

    Energy Technology Data Exchange (ETDEWEB)

    Fang Jing [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Shan Xiaoquan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)], E-mail: xiaoquan@rcees.ac.cn; Wen Bei [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)], E-mail: bwen@rcees.ac.cn; Lin Jinming [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Owens, Gary [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2009-04-15

    The stability of TiO{sub 2} nanoparticles in soil suspensions and their transport behavior through saturated homogeneous soil columns were studied. The results showed that TiO{sub 2} could remain suspended in soil suspensions even after settling for 10 days. The suspended TiO{sub 2} contents in soil suspensions after 24 h were positively correlated with the dissolved organic carbon and clay content of the soils, but were negatively correlated with ionic strength, pH and zeta potential. In soils containing soil particles of relatively large diameters and lower solution ionic strengths, a significant portion of the TiO{sub 2} (18.8-83.0%) readily passed through the soils columns, while TiO{sub 2} was significantly retained by soils with higher clay contents and salinity. TiO{sub 2} aggregate sizes in the column outflow significantly increased after passing through the soil columns. The estimated transport distances of TiO{sub 2} in some soils ranged from 41.3 to 370 cm, indicating potential environmental risk of TiO{sub 2} nanoparticles to deep soil layers. - TiO{sub 2} nanoparticles could efficiently suspend in soil suspensions and potentially transport to deeper soil layers.

  19. Stability of titania nanoparticles in soil suspensions and transport in saturated homogeneous soil columns

    International Nuclear Information System (INIS)

    Fang Jing; Shan Xiaoquan; Wen Bei; Lin Jinming; Owens, Gary

    2009-01-01

    The stability of TiO 2 nanoparticles in soil suspensions and their transport behavior through saturated homogeneous soil columns were studied. The results showed that TiO 2 could remain suspended in soil suspensions even after settling for 10 days. The suspended TiO 2 contents in soil suspensions after 24 h were positively correlated with the dissolved organic carbon and clay content of the soils, but were negatively correlated with ionic strength, pH and zeta potential. In soils containing soil particles of relatively large diameters and lower solution ionic strengths, a significant portion of the TiO 2 (18.8-83.0%) readily passed through the soils columns, while TiO 2 was significantly retained by soils with higher clay contents and salinity. TiO 2 aggregate sizes in the column outflow significantly increased after passing through the soil columns. The estimated transport distances of TiO 2 in some soils ranged from 41.3 to 370 cm, indicating potential environmental risk of TiO 2 nanoparticles to deep soil layers. - TiO 2 nanoparticles could efficiently suspend in soil suspensions and potentially transport to deeper soil layers

  20. Smectite clay--inorganic nanoparticle mixed suspensions: phase behaviour and rheology.

    Science.gov (United States)

    Bailey, Louise; Lekkerkerker, Henk N W; Maitland, Geoffrey C

    2015-01-14

    Smectite clay minerals and their suspensions have long been of both great scientific and applications interest and continue to display a remarkable range of new and interesting behaviour. Recently there has been an increasing interest in the properties of mixed suspensions of such clays with nanoparticles of different size, shape and charge. This review aims to summarize the current status of research in this area focusing on phase behaviour and rheological properties. We will emphasize the rich range of data that has emerged for these systems and the challenges they present for future investigations. The review starts with a brief overview of the behaviour and current understanding of pure smectite clays and their suspensions. We then cover the work on smectite clay-inorganic nanoparticle mixed suspensions according to the shape and charge of the nanoparticles - spheres, rods and plates either positively or negatively charged. We conclude with a summary of the overarching trends that emerge from these studies and indicate where gaps in our understanding need further research for better understanding the underlying chemistry and physics.

  1. Considerable Variation of Antibacterial Activity of Cu Nanoparticles Suspensions Depending on the Storage Time, Dispersive Medium, and Particle Sizes

    Directory of Open Access Journals (Sweden)

    Olga V. Zakharova

    2015-01-01

    Full Text Available Suspensions of Cu nanoparticles are promising for creating the new class of alternative antimicrobial products. In this study we examined copper nanoparticles of various sizes obtained by the method of wire electric explosion: nanopowder average size 50 nm (Cu 50 and 100 nm (Cu 100. The paper presents the complex study of the influence of physicochemical properties such as particle size and concentration of the freshly prepared and 24-hour suspensions of Cu nanoparticles in distilled water and physiological solution upon their toxicity to bacteria E. coli M-17. Ionic solution of Cu2+ and sodium dichloroisocyanurate was used for comparison study. It has been shown that decrease in the nanoparticle size leads to changes in the correlation between toxicity and concentration as toxicity peaks are observed at low concentrations (0.0001⋯0.01 mg/L. It has been observed that antibacterial properties of Cu 50 nanoparticle suspensions are ceased after 24-hour storage, while for Cu 100 suspensions no correlation between antibacterial properties and storage time has been noted. Cu 100 nanoparticle suspensions at 10 mg/L concentration display higher toxicity at substituting physiological solution for water than Cu 50 suspensions. Dependence of the toxicity on the mean particle aggregates size in suspension was not revealed.

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

    OpenAIRE

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-23

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

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

    Science.gov (United States)

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

    2015-06-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  6. Surface Modification of Silica Nanoparticles with Titanium Tetraisopropoxide and Evaluation of their Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Leila Mazaheri

    2012-12-01

    Full Text Available Silica nanoparticles were modified with titanium tetraisopropoxide (TTIP via atwo-step sol-gel route. The modified silica nanoparticles were characterized using FTIR spectroscopy, thermal gravimetric analysis (TGA and EDAX elemental analysis. Photocatalytic activity of the modified nanocomposites was evaluated by photo-activated degradation of Rhodamine B (Rh.B dyestuff, as a colorant model, in distilled water. Reduction in Rh.B concentration in aqueous solution was evaluated by UV-visible spectroscopy and with the aid of visual observations. The FTIR spectroscopy results confirmed the formation of Ti-O-Si chemical bond on the surfaceof silica nanoparticles. TGA test results showed that the weight loss of the modified sample is due to deterioration of the alkoxy groups of the SiO2 surface. According to the results of EDAX elemental analysis, the presence of carbon and titanium in the structure of the modified samples and also reduction in oxygen levels are attributed to the chemical interactions due to surface chemical modification. Carbon detection in the composition can be attributed to the presence of isopropoxide in titanium tetraisopropoxide compound. The results also revealed that, with TiO2 grafting on the silica nanoparticles surface, absorption in UV region is increased and that the silica nanoparticles modified with titanate compound show photocatalytic characteristics and degradation ability of Rh.B dyestuff under UV light irradiation. It became also evident that the photocatalytic activity of the modified nanoparticles is less than TiO2 nanoparticles. However, by inclusion of modified silica nanoparticles into the polymeric coating, the photocatalytic properties of the coating can be established. Although modified silica nanoparticles have less photocatalytic activity compared to TiO2 nanoparticles, but they cause less damage to the polymer matrix.

  7. Synthesis, characterization and magnetorheological properties of carbonyl iron suspension with superparamagnetic nanoparticles as an additive

    International Nuclear Information System (INIS)

    Leong, Siti Asma’ Nikmat; Mohd Samin, Pakharuddin; Idris, Ani; Rahman, Azura Hanis A; Mazlan, Saiful Amri

    2016-01-01

    Magnetorheological (MR) fluids are suspensions of micron-sized particles dispersed in carrier fluid. Due to high density magnetic particles, MR fluids are facing the problem with the instability of the suspension caused by high settling rate. Recently, researches have been conducted on the advantages of using the mixture of magnetic nanoparticles and microparticles, called bidisperse MR fluids. However, even though the sedimentation stability is improved, there is a reduction in dynamic yield stress when the nanoparticle is introduced. In this work, the investigation of magnetic iron nanoparticles (γ-Fe 2 O 3 ) as an additive to magnetic carbonyl iron (CI) suspension has been proposed so as to improve the sedimentation stability and redispersibility, but at the same time enhance the MR performance. The results indicated that the addition of nanoparticles reduced the sedimentation rate, improved redispersibility and enhanced the rheological performance of MR fluids as the particle fill the voids between the microparticles and strengthened the interparticle chains contributing to well-arranged particle structures. (paper)

  8. Harmonic decomposition of magneto-optical signal from suspensions of superparamagnetic nanoparticles

    Science.gov (United States)

    Patterson, Cody; Syed, Maarij; Takemura, Yasushi

    2018-04-01

    Magnetic nanoparticles (MNPs) are widely used in biomedical applications. Characterizing dilute suspensions of superparamagnetic iron oxide nanoparticles (SPIONs) in bio-relevant media is particularly valuable for magnetic particle imaging, hyperthermia, drug delivery, etc. Here, we study dilute aqueous suspensions of single-domain magnetite nanoparticles using an AC Faraday rotation (FR) setup. The setup uses an oscillating magnetic field (800 Hz) which generates a multi-harmonic response. Each harmonic is collected and analyzed using the Fourier components of the theoretical signal determined by a Langevin-like magnetization. With this procedure, we determine the average magnetic moment per particle μ , particle number density n, and Verdet constant of the sample. The fitted values of μ and n are shown to be consistent across each harmonic. Additionally, we present the results of these parameters as n is varied. The large values of μ reveal the possibility of clustering as reported in other literature. This suggests that μ is representative of the average magnetic moment per cluster of nanoparticles. Multiple factors, including the external magnetic field, surfactant degradation, and laser absorption, can contribute to dynamic and long-term aggregation leading to FR signals that represent space- and time-averaged sample parameters. Using this powerful analysis procedure, future studies are aimed at determining the clustering mechanisms in this AC system and characterizing SPION suspensions at different frequencies and viscosities.

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

    Science.gov (United States)

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

  10. Tuning the Electronic Structure of Titanium Oxide Support to Enhance the Electrochemical Activity of Platinum Nanoparticles

    KAUST Repository

    Shi, Feifei; Baker, L. Robert; Hervier, Antoine; Somorjai, Gabor A.; Komvopoulos, Kyriakos

    2013-01-01

    on pristine TiO2 support were achieved by tuning the electronic structure of the titanium oxide support of Pt nanoparticle catalysts. This was accomplished by adding oxygen vacancies or doping with fluorine. Experimental trends are interpreted in the context

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

    Science.gov (United States)

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

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

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    NARCIS (Netherlands)

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

    2017-01-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

  16. Effect of Magnetic Nanoparticles on Tobacco BY-2 Cell Suspension Culture

    Science.gov (United States)

    Krystofova, Olga; Sochor, Jiri; Zitka, Ondrej; Babula, Petr; Kudrle, Vit; Adam, Vojtech; Kizek, Rene

    2012-01-01

    Nanomaterials are structures whose exceptionality is based on their large surface, which is closely connected with reactivity and modification possibilities. Due to these properties nanomaterials are used in textile industry (antibacterial textiles with silver nanoparticles), electronics (high-resolution imaging, logical circuits on the molecular level) and medicine. Medicine represents one of the most important fields of application of nanomaterials. They are investigated in connection with targeted therapy (infectious diseases, malignant diseases) or imaging (contrast agents). Nanomaterials including nanoparticles have a great application potential in the targeted transport of pharmaceuticals. However, there are some negative properties of nanoparticles, which must be carefully solved, as hydrophobic properties leading to instability in aqueous environment, and especially their possible toxicity. Data about toxicity of nanomaterials are still scarce. Due to this fact, in this work we focused on studying of the effect of magnetic nanoparticles (NPs) and modified magnetic nanoparticles (MNPs) on tobacco BY-2 plant cell suspension culture. We aimed at examining the effect of NPs and MNPs on growth, proteosynthesis—total protein content, thiols—reduced (GSH) and oxidized (GSSG) glutathione, phytochelatins PC2-5, glutathione S-transferase (GST) activity and antioxidant activity of BY-2 cells. Whereas the effect of NPs and MNPs on growth of cell suspension culture was only moderate, significant changes were detected in all other biochemical parameters. Significant changes in protein content, phytochelatins levels and GST activity were observed in BY-2 cells treated with MNPs nanoparticles treatment. Changes were also clearly evident in the case of application of NPs. Our results demonstrate the ability of MNPs to negatively affect metabolism and induce biosynthesis of protective compounds in a plant cell model represented by BY-2 cell suspension culture. The

  17. Titanium Dioxide Nanoparticles in Food and Personal Care Products

    Science.gov (United States)

    Weir, Alex; Westerhoff, Paul; Fabricius, Lars

    2012-01-01

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

  18. 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.

  19. Shear viscosity enhancement in water–nanoparticle suspensions

    International Nuclear Information System (INIS)

    Balasubramanian, Ganesh; Sen, Swarnendu; Puri, Ishwar K.

    2012-01-01

    Equilibrium molecular dynamics simulations characterize the increase in the shear viscosity of water around a suspended silicon dioxide nanoparticle. Water layering on the solid surface decreases the fraction of adjacent fluid molecules that are more mobile and hence less viscous, thereby increasing the shear viscosity. The contribution of the nanoparticle surface area to this rheological behavior is identified and an empirical model that accounts for it is provided. The model successfully reproduces the shear viscosity predictions from previous experimental measurements as well as our simulations. -- Highlights: ► Layering of water on the solid surfaces increases the fraction of less mobile molecules adjacent to them. ► A nondimensional parameter predicts of viscosity enhancement due to particle shape, volume fraction. ► Model predictions agree with the results of atomistic simulations and experimental measurements.

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

    Science.gov (United States)

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

    2015-06-02

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

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

    Science.gov (United States)

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

    2018-03-01

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

  2. Electrorheological properties of suspensions of hollow globular titanium oxide/polypyrrole particles

    Czech Academy of Sciences Publication Activity Database

    Sedlačík, M.; Mrlík, M.; Pavlínek, V.; Sáha, P.; Quadrat, Otakar

    2012-01-01

    Roč. 290, č. 1 (2012), s. 41-48 ISSN 0303-402X R&D Projects: GA ČR GA202/09/1626 Institutional research plan: CEZ:AV0Z40500505 Keywords : electrorheology * titanium oxide * hollow globular clusters Subject RIV: JI - Composite Materials Impact factor: 2.161, year: 2012

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

    Science.gov (United States)

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

    2015-03-04

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

  4. Uptake, accumulation, and biotransformation of metal oxide nanoparticles by a marine suspension-feeder

    International Nuclear Information System (INIS)

    Montes, Milka O.; Hanna, Shannon K.; Lenihan, Hunter S.; Keller, Arturo A.

    2012-01-01

    Highlights: ► Suspension-feeding by mussels can greatly alter mobility and fate of metal oxide nanoparticles. ► Bioprocessing of metal oxide nanoparticles by mussels removes large fraction from water column. ► Mussels repackage metal oxide nanoparticles in highly concentrated pseudofeces. ► Novel biological pathway between major compartments in marine systems. ► Very different outcome for ZnO and CeO 2 nanoparticles based on their solubility. - Abstract: A growing body of evidence indicates that some engineered nanoparticles (ENPs) are toxic to organisms that perform important ecosystem services in terrestrial and aquatic ecosystems. However, toxicity can be influenced by the biotransformation of contaminants, including ENPs, as it may alter the fate and transport of these substances. In turn, fate and transport can influence their bioavailability. To understand how biotransformation influences the fate and transport of ENPs in marine ecosystems, we exposed suspension-feeding mussels, Mytilus galloprovincialis, to two common nano-metal oxides, CeO 2 and ZnO, over a range of concentrations from 1 mg L −1 to 10 mg L −1 , in a laboratory experiment. Mussels exposed to 10 mg L −1 accumulated 62 μg g −1 of Ce and 880 μg g −1 of Zn on a dry tissue basis but rejected 21,000 μg g −1 for Ce and 63,000 μg g −1 for Zn in pseudofeces. Scanning electron microscope evidence indicates CeO 2 remained as ENPs but ZnO did not after being rejected by the mussels. Mussels filtered most of the CeO 2 from the aqueous media, while a significant fraction of Zn remained in solution. Differences in ENP solubility affect ENP uptake, excretion, and accumulation in mussels. Our study highlights the potential role of marine suspension feeders in biotransformation of ENPs.

  5. Stability and phase transfer of catalytically active platinum nanoparticle suspensions

    International Nuclear Information System (INIS)

    Sriram, Indira; Curtin, Alexandra E.; Chiaramonti, Ann N.; Cuchiaro, J. Hunter; Weidner, Andrew R.; Tingley, Tegan M.; Greenlee, Lauren F.; Jeerage, Kavita M.

    2015-01-01

    In this work, we present a robust synthesis protocol for platinum nanoparticles that yields a monomodal dispersion of particles that are approximately 100 nm in diameter. We determine that these particles are actually agglomerates of much smaller particles, creating a “raspberry” morphology. We demonstrate that these agglomerates are stable at room temperature for at least 8 weeks by dynamic light scattering. Furthermore, we demonstrate consistent electrocatalytic activity for methanol oxidation. Finally, we quantitatively explore the relationship between dispersion solvent and particle agglomeration; specifically, particles are found to agglomerate abruptly as solvent polarity decreases

  6. Stability and phase transfer of catalytically active platinum nanoparticle suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Sriram, Indira; Curtin, Alexandra E.; Chiaramonti, Ann N.; Cuchiaro, J. Hunter; Weidner, Andrew R.; Tingley, Tegan M.; Greenlee, Lauren F.; Jeerage, Kavita M., E-mail: jeerage@boulder.nist.gov [National Instrument of Standards and Technology, Applied Chemicals and Materials Division (United States)

    2015-05-15

    In this work, we present a robust synthesis protocol for platinum nanoparticles that yields a monomodal dispersion of particles that are approximately 100 nm in diameter. We determine that these particles are actually agglomerates of much smaller particles, creating a “raspberry” morphology. We demonstrate that these agglomerates are stable at room temperature for at least 8 weeks by dynamic light scattering. Furthermore, we demonstrate consistent electrocatalytic activity for methanol oxidation. Finally, we quantitatively explore the relationship between dispersion solvent and particle agglomeration; specifically, particles are found to agglomerate abruptly as solvent polarity decreases.

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

    Science.gov (United States)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-01

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

  9. Nanofluid bioconvection in water-based suspensions containing nanoparticles and oxytactic microorganisms: oscillatory instability

    Directory of Open Access Journals (Sweden)

    Kuznetsov Andrey

    2011-01-01

    Full Text Available Abstract The aim of this article is to propose a novel type of a nanofluid that contains both nanoparticles and motile (oxytactic microorganisms. The benefits of adding motile microorganisms to the suspension include enhanced mass transfer, microscale mixing, and anticipated improved stability of the nanofluid. In order to understand the behavior of such a suspension at the fundamental level, this article investigates its stability when it occupies a shallow horizontal layer. The oscillatory mode of nanofluid bioconvection may be induced by the interaction of three competing agencies: oxytactic microorganisms, heating or cooling from the bottom, and top or bottom-heavy nanoparticle distribution. The model includes equations expressing conservation of total mass, momentum, thermal energy, nanoparticles, microorganisms, and oxygen. Physical mechanisms responsible for the slip velocity between the nanoparticles and the base fluid, such as Brownian motion and thermophoresis, are accounted for in the model. An approximate analytical solution of the eigenvalue problem is obtained using the Galerkin method. The obtained solution provides important physical insights into the behavior of this system; it also explains when the oscillatory mode of instability is possible in such system.

  10. Excitation of high energy levels under laser exposure of suspensions of nanoparticles in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Shafeev, G.A. [Wave Research Center of A.M. Prokhorov General Physics Institute, 38, Vavilov Street, 119991 Moscow (Russian Federation)], E-mail: shafeev@kapella.gpi.ru; Simakin, A.V. [Wave Research Center of A.M. Prokhorov General Physics Institute, 38, Vavilov Street, 119991 Moscow (Russian Federation); Bozon-Verduraz, F. [ITODYS, UMR CNRS 7086, Universite Paris 7-Denis Diderot, 2, place Jussieu, 75251 Paris cedex 05 (France); Robert, M. [Laboratoire d' Electrochimie Moleculaire, UMR CNRS 7591, Universite Paris 7 Denis Diderot, 2, place Jussieu, 75251 Paris cedex 05 (France)

    2007-12-15

    Laser exposure of suspensions of nanoparticles in liquids leads to excitation of high energy levels in both liquid and nanoparticle material. The emission spectrum of the colloidal solution under exposure of a suspension metallic nanoparticles in water to radiation of a Nd:YAG laser of a picosecond range of pulse duration is discussed. Excitation of nuclear energy levels and neutron release is experimentally studied on the model system of transmutation of Hg into Au that occurs under exposure of Hg nanodrops suspended in D{sub 2}O. The proposed mechanism involves: (i) emission of X-ray photons by Hg nanoparticles upon laser exposure, leading to neutron release from D{sub 2}O, (ii) initiation of Hg {yields} Au transmutation by the capture of neutrons. The effect of transmutation is more pronounced using {sup 196}Hg isotope instead of Hg of natural isotope composition. The influence of laser pulse duration on the degree of transmutation (from fs through ns range) is discussed.

  11. Charge density modification of carboxylated cellulose nanocrystals for stable silver nanoparticles suspension preparation

    International Nuclear Information System (INIS)

    Hoeng, Fanny; Denneulin, Aurore; Neuman, Charles; Bras, Julien

    2015-01-01

    Synthesis of silver nanoparticles using cellulose nanocrystals (CNC) has been found to be a great method for producing metallic particles in a sustainable way. In this work, we propose to evaluate the influence of the charge density of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-oxidized CNC on the morphology and the stability of synthetized silver nanoparticles. Silver nanoparticles were obtained by sol–gel reaction using borohydride reduction, and charge density of TEMPO-oxidized CNC was tuned by an amine grafting. The grafting was performed at room temperature and neutral pH. Crystallinity and morphology were kept intact during the peptidic reaction on CNC allowing knowing the exact impact of the charge density. Charge density has been found to have a strong impact on shape, organization, and suspension stability of resulting silver particles. Results show an easy way to tune the charge density of CNC and propose a sustainable way to control the morphology and stability of silver nanoparticles in aqueous suspension

  12. A molecular dynamics study of liquid layering and thermal conductivity enhancement in nanoparticle suspensions

    Science.gov (United States)

    Paul, J.; Madhu, A. K.; Jayadeep, U. B.; Sobhan, C. B.; Peterson, G. P.

    2018-03-01

    Liquid layering is considered to be one of the factors contributing to the often anomalous enhancement in thermal conductivity of nanoparticle suspensions. The extent of this layering was found to be significant at lower particle sizes, as reported in an earlier work by the authors. In continuation to that work, an investigation was conducted to better understand the fundamental parameters impacting the reported anomalous enhancement in thermal conductivity of nanoparticle suspensions (nanofluids), utilizing equilibrium molecular dynamics simulations in a copper-argon system. Nanofluids containing nanoparticles of size less than 6 nm were investigated and studied analytically. The heat current auto-correlation function in the Green-Kubo formulation for thermal conductivity was decomposed into self-correlations and cross-correlations of different species and the kinetic, potential, collision and enthalpy terms of the dominant portion of the heat current vector. The presence of liquid layering around the nanoparticle was firmly established through simulations that show the dominant contribution of Ar-Ar self-correlation and the trend displayed by the kinetic-potential cross-correlation within the argon species.

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

    KAUST Repository

    Memon, Nasir

    2013-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Mirco Bundschuh

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

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

    Science.gov (United States)

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

    2008-09-01

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

  16. X-ray absorption investigation of titanium oxynitride nanoparticles obtained from laser pyrolysis

    International Nuclear Information System (INIS)

    Simon, Pardis; March, Katia; Stéphan, Odile; Leconte, Yann; Reynaud, Cécile; Herlin-Boime, Nathalie; Flank, Anne-Marie

    2013-01-01

    Highlights: • Original Ti(O,N) nanoparticles with a TiO FCC structure were synthesized by laser pyrolysis. • EELS and XAS allows to demonstrate that the nanoparticles are a solid solution of N and O in Ti. • Upon heat treatment, oxidation occurs from the surface with survival of FCC contribution till 400 °C. • Optical properties (absorption in the visible range) can be adjusted through the control of oxidation state. - Abstract: This work presents a structural study by X-ray Absorption Spectroscopy (XAS) and Electron Energy-Loss Spectroscopy (EELS) of complex titanium oxynitride nanoparticles (Ti(O,N)), synthesized by laser pyrolysis from titanium tetraisopropoxide and ammonia as precursors. Previous structural characterizations obtained by XRD and XPS have shown that the nanoparticles present a TiO type face-centered cubic (FCC) structure but with three different oxidation degree for titanium. The synthesis of this kind of titanium oxide or oxynitride nanoparticles is very unusual. Moreover, their properties are highly dependent of their structure. EELS spectrum-imaging data were therefore used for mapping the different chemical species. These measurements reveal that the nanoparticles are composed of a FCC solid solution of nitrogen and oxygen in titanium. The local structure around Ti was then studied. XANES measurements show an absorption threshold corresponding to a global valence state between Ti 3+ and Ti 4+ , with a pre-edge structure characteristic of a mix between a face-centered cubic (FCC) structure and a disordered TiO 2 structure whereas the EXAFS signal is dominated by the contribution of the FCC structure. Oxidative heat-treatments have been performed from 250 to 450 °C in order to follow the transition towards the dioxide phase. EELS measurements show that the oxidation occurs from the surface of the nanoparticles. XAS show that this transition does not involve any other crystallographic phase than TiO 2 , mainly in its anatase form, and

  17. Comparison between experimental and predicted specific absorption rate of functionalized iron oxide nanoparticle suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Yuan [Mechanical, Aerospace and Nuclear Engineering Department Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Tasciuc, Diana-Andra Borca, E-mail: borcad@rpi.edu [Mechanical, Aerospace and Nuclear Engineering Department Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

    2011-10-15

    Radio-frequency heated magnetic nanoaparticle suspensions have potential applications in cancer hyperthermia. To optimize these systems for hyperthermia applications it is important to be able to predict how their heat generation or specific absorption rate (SAR) is influenced by various factors, including nanoparticle coating or functionalization and aggregation. However, at present it is unclear how well-existing models predict experimental SAR results. Direct comparisons between predicted and measured SAR are scarce, despite an abundance of works reporting on heat generation rate of various magnetic nanoparticles suspensions. The main objective of this paper is to experimentally assess the validity of current models for SAR and extract information on the effects of coating and aggregation on heat generation rate. In this context, AC susceptibility and magnetization of suspensions of uncoated particles, as well as particles with aminosilane and carboxymethyl-dextran functionalizations, were measured. These properties were then used to predict the heat generation rate in alternating magnetic field starting from first principles, which was then compared to measured SAR. It was found that experimental SAR agrees relatively well with predictions (by a factor of two) when using experimental susceptibility values for the SAR calculation. However, for uncoated and amine-functionalized particles poor agreement (more than an order of magnitude difference) was found when the experimental susceptibility was substituted with predictions based on the Debye model. This apparent discrepancy is attributed to dipolar interactions between nanoparticles within aggregates in these samples, which enhances the imaginary part of the susceptibility and, consequently, the SAR values. The results also suggest that the thermal resistance effect of the coating has little influence on the SAR. - Highlights: > Thermal resistance of nanoparticle coating has little impact on heat dissipation

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    Science.gov (United States)

    Grande, Fedora; Tucci, Paola

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sarah Triboulet

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

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

    Science.gov (United States)

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

    2015-01-01

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

  2. Discrete deposition of hydroxyapatite nanoparticles on a titanium implant with predisposing substrate microtopography accelerated osseointegration

    International Nuclear Information System (INIS)

    Nishimura, Ichiro; Huang Yuhong; Butz, Frank; Ogawa, Takahiro; Lin, Audrey; Wang, Chiachien Jake

    2007-01-01

    We report here a new versatile method to deposit discrete hydroxyapatite (HA) nanoparticles on a titanium (Ti) implant with predisposing substrate microtopography, which exhibited an unexpectedly robust biological effect. Commercially pure Ti substrates were treated with 3-aminopropyltriethoxysilane, on which HA nanoparticles (20 nm) were deposited and chemically bonded to TiO 2 . The HA deposition rate was linearly related to the treatment time and HA nanoparticles were deposited on up to 50% of the substrate surface. As a result, the discrete deposition of HA nanoparticles generated novel 20-40 nm nanotopography on the Ti substrate with microtopography that was smooth (turned) or roughened by double acid etching (DAE). The experimental implants with or without HA nanoparticles were surgically placed in rat femur and an implant push-in test was performed after two weeks of healing. The deposition of HA nanoparticles on the DAE surface increased the mechanical withstanding load by 129% and 782% as compared to the control DAE and turned implants, respectively. Micro-computed tomography-based 3D bone morphometry revealed equivalent bone volumes around the DAE implant with or without HA nanoparticles. These data suggest that the discrete deposition of HA nanoparticles accelerates the early osseointegration process, likely through increased shear bonding strengths

  3. Discrete deposition of hydroxyapatite nanoparticles on a titanium implant with predisposing substrate microtopography accelerated osseointegration

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Ichiro [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Huang Yuhong [Chemat Technology, Incorporated, Northridge, CA (United States); Butz, Frank [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Ogawa, Takahiro [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Lin, Audrey [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Wang, Chiachien Jake [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States)

    2007-06-20

    We report here a new versatile method to deposit discrete hydroxyapatite (HA) nanoparticles on a titanium (Ti) implant with predisposing substrate microtopography, which exhibited an unexpectedly robust biological effect. Commercially pure Ti substrates were treated with 3-aminopropyltriethoxysilane, on which HA nanoparticles (20 nm) were deposited and chemically bonded to TiO{sub 2}. The HA deposition rate was linearly related to the treatment time and HA nanoparticles were deposited on up to 50% of the substrate surface. As a result, the discrete deposition of HA nanoparticles generated novel 20-40 nm nanotopography on the Ti substrate with microtopography that was smooth (turned) or roughened by double acid etching (DAE). The experimental implants with or without HA nanoparticles were surgically placed in rat femur and an implant push-in test was performed after two weeks of healing. The deposition of HA nanoparticles on the DAE surface increased the mechanical withstanding load by 129% and 782% as compared to the control DAE and turned implants, respectively. Micro-computed tomography-based 3D bone morphometry revealed equivalent bone volumes around the DAE implant with or without HA nanoparticles. These data suggest that the discrete deposition of HA nanoparticles accelerates the early osseointegration process, likely through increased shear bonding strengths.

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

    International Nuclear Information System (INIS)

    Shih Yanghsin; Zhuang Chengming; Tso Chihping; Lin Chenghan

    2012-01-01

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

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Science.gov (United States)

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

  7. UV-induced photochemical transformations of citrate-capped silver nanoparticle suspensions

    International Nuclear Information System (INIS)

    Gorham, Justin M.; MacCuspie, Robert I.; Klein, Kate L.; Fairbrother, D. Howard; Holbrook, R. David

    2012-01-01

    Due to the increasing use of silver nanoparticles (AgNPs) in consumer products, it is essential to understand how variables, such as light exposure, may change the physical and chemical characteristics of AgNP suspensions. To this end, the effect of 300 nm ultraviolet (UV) light on (20, 40, 60 and 80) nm citrate-capped AgNP suspensions has been investigated. As a consequence of irradiation, the initial yellow hue of the AgNP suspensions is transformed towards a near colorless solution due to the loss of the surface plasmon resonance (SPR) absorbance. The decrease in SPR absorbance followed a first-order decay process for all particle sizes with a rate constant that increased linearly with the AgNP specific surface area and non-linearly with light intensity. The rate of loss of the SPR absorbance decreased with increasing citrate concentration, suggesting a surface-mediated transformation. Absorbance, atomic force microscopy, and dynamic light scattering results all indicated that AgNP photolysis was accompanied by a diameter decrease and occasional aggregation. Furthermore, in situ transmission electron microscopy imaging using a specialized liquid cell also showed a decrease in the particle size and the formation of a core–shell structure in UV-exposed AgNPs. X-ray photoelectron spectroscopy analysis suggested that this shell consisted of oxidized silver. The SPR in UV-exposed AgNP suspensions could be regenerated by addition of a strong reducing agent (NaBH 4 ), supporting the idea that oxidized silver is present after photolysis. Evidence for UV-enhanced dissolution and the production of silver ions was obtained with the Donnan membrane technique. This study reveals that the physico-chemical properties of aqueous AgNP suspensions will change significantly upon exposure to UV light, with implications for environmental health and safety risk assessments.

  8. Short-term exposure to gold nanoparticle suspension impairs swimming behavior in a widespread calanoid copepod.

    Science.gov (United States)

    Michalec, François-Gaël; Holzner, Markus; Barras, Alexandre; Lacoste, Anne-Sophie; Brunet, Loïc; Lee, Jae-Seong; Slomianny, Christian; Boukherroub, Rabah; Souissi, Sami

    2017-09-01

    Calanoid copepods play an important role in the functioning of marine and brackish ecosystems. Information is scarce on the behavioral toxicity of engineered nanoparticles to these abundant planktonic organisms. We assessed the effects of short-term exposure to nonfunctionalized gold nanoparticles on the swimming behavior of the widespread estuarine copepod Eurytemora affinis. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of males, ovigerous and non-ovigerous females. We quantified changes in their swimming activity and in the kinematics and geometrical properties of their motion, three important descriptors of the motility patterns of zooplankters. In females, exposure to gold nanoparticles in suspension (11.4 μg L -1 ) for 30 min caused depressed activity and lower velocity and acceleration, whereas the same exposure caused minimal effects in males. This response differs clearly from the hyperactive behavior that is commonly observed in zooplankters exposed to pollutants, and from the generally lower sensitivity of female copepods to toxicants. Accumulation of gold nanoparticles on the external appendages was not observed, precluding mechanical effects. Only very few nanoparticles appeared sporadically in the inner part of the gut in some samples, either as aggregates or as isolated nanoparticles, which does not suggest systemic toxicity resulting from pronounced ingestion. Hence, the precise mechanisms underlying the behavioral toxicity observed here remain to be elucidated. These results demonstrate that gold nanoparticles can induce marked behavioral alterations at very low concentration and short exposure duration. They illustrate the applicability of swimming behavior as a suitable and sensitive endpoint for investigating the toxicity of nanomaterials present in estuarine and marine environments. Changes in swimming behavior may impair the ability of planktonic copepods to interact with their environment

  9. Investigations of suspension stability of iron oxide nanoparticles using time-resolved UV–visible spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vikram, S.; Vasanthakumari, R. [B. S. Abdur Rahman University, Polymer Nanotechnology Centre (India); Tsuzuki, Takuya [Australian National University, Research School of Engineering, College of Engineering and Computer Science (Australia); Rangarajan, Murali, E-mail: r-murali@cb.amrita.edu [Amrita University, Center of Excellence in Advanced Materials and Green Technologies, Amrita School of Engineering Coimbatore (India)

    2016-09-15

    This study examines the suspension stability of iron oxide nanoparticles of different sizes, magnetic susceptibility, and saturation magnetization over long time scales in dilute systems using time-resolved UV–visible spectroscopy. The effects of citric acid as a chelating agent and applied external magnetic field are also studied. UV–visible spectra are obtained at different times for citric-acid-stabilized nanoparticles dispersed in water, and the peak absorbance is tracked with time, in the presence and absence of external magnetic fields. It is seen that the nanoparticles sediment slowly even in the absence of chain formation, with the phenomenon occurring in two-to-three regimes for the systems studied. Sedimentation exhibits either exponential or power-law behavior of maximum absorbance with time. In the dilute dispersions studied, thermal dispersion is about two orders of magnitude stronger than van der Waals interactions, and chain formation is not easy. Yet, it is likely that local anisotropic structures of the nanoparticles form, through which the attractive interactions result in sedimentation. Citric acid gradually stabilizes the aggregating particles; after an initial faster sedimentation, electrostatic repulsion causes the particles to segregate, as observed by a linear increase in the concentration of the nanoparticles at long times. In the presence of magnetic field, stabilization effects are significantly reduced. It is seen that though the attractive force between the nanoparticles and the external field is smaller than Brownian forces, together with van der Waals interactions, these attractive forces likely act as directing agents facilitating sedimentation. This study demonstrates that aggregation-induced sedimentation of magnetic nanoparticles is likely to play a significant role in magnetic drug targeting even when the particles are stabilized with chelating agents.Graphical abstract.

  10. Investigations of suspension stability of iron oxide nanoparticles using time-resolved UV–visible spectroscopy

    International Nuclear Information System (INIS)

    Vikram, S.; Vasanthakumari, R.; Tsuzuki, Takuya; Rangarajan, Murali

    2016-01-01

    This study examines the suspension stability of iron oxide nanoparticles of different sizes, magnetic susceptibility, and saturation magnetization over long time scales in dilute systems using time-resolved UV–visible spectroscopy. The effects of citric acid as a chelating agent and applied external magnetic field are also studied. UV–visible spectra are obtained at different times for citric-acid-stabilized nanoparticles dispersed in water, and the peak absorbance is tracked with time, in the presence and absence of external magnetic fields. It is seen that the nanoparticles sediment slowly even in the absence of chain formation, with the phenomenon occurring in two-to-three regimes for the systems studied. Sedimentation exhibits either exponential or power-law behavior of maximum absorbance with time. In the dilute dispersions studied, thermal dispersion is about two orders of magnitude stronger than van der Waals interactions, and chain formation is not easy. Yet, it is likely that local anisotropic structures of the nanoparticles form, through which the attractive interactions result in sedimentation. Citric acid gradually stabilizes the aggregating particles; after an initial faster sedimentation, electrostatic repulsion causes the particles to segregate, as observed by a linear increase in the concentration of the nanoparticles at long times. In the presence of magnetic field, stabilization effects are significantly reduced. It is seen that though the attractive force between the nanoparticles and the external field is smaller than Brownian forces, together with van der Waals interactions, these attractive forces likely act as directing agents facilitating sedimentation. This study demonstrates that aggregation-induced sedimentation of magnetic nanoparticles is likely to play a significant role in magnetic drug targeting even when the particles are stabilized with chelating agents.Graphical abstract

  11. Gas-phase Crystallization of Titanium Dioxide Nanoparticles

    International Nuclear Information System (INIS)

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

    2002-01-01

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

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

    Science.gov (United States)

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

  13. Strong saturable absorption of black titanium oxide nanoparticle films

    Science.gov (United States)

    Zhang, Rong-Fang; Guo, Deng-Zhu; Zhang, Geng-Min

    2017-12-01

    Nonlinear optical materials with strong saturable absorption (SA) properties play an essential role in passive mode-locking generation of ultrafast lasers. Here we report black TiO2-x nanoparticles are promising candidate for such an application. Black TiO2-x nanoparticles are synthesized by using cathodic plasma electrolysis, and nanoparticle films are deposited on optical glass plates via natural sedimentation and post annealing. Characterization of the samples with TEM, SEM, XRD and XPS reveal that nanoparticles have diameters of 8-70 nm, and are in polycrystalline structure and co-existence of anatase, rutile and abundant oxygen-deficient phases. Optical transmittance and reflectance measurements with a UV/VIS/NIR spectrophotometer evidence an excellent wide-spectral optical absorption property. The nonlinear optical properties of the samples were measured by using open-aperture Z-scan technique with picosecond 532-nm laser, and verified by direct transmission measurements using nanosecond 1064-nm laser. Strong SA behavior was detected, and the nonlinear absorption coefficient is as high as β = - 4.9 × 10-8 m/W, at least two orders larger than most previous reports on ordinary TiO2. The strong SA behaviors are ascribed to the existence of plenty surface states and defect states within bandgap, and the relaxation rates of electrons from upper energy levels to lower ones are much slower than excitation rates.

  14. Ultrastructural analyses of platelets and fibrin networks in BALB/c mice after inhalation of spherical and rod-shaped titanium nanoparticles

    CSIR Research Space (South Africa)

    Oosthuizen, MA

    2010-10-01

    Full Text Available Engineered nanoparticles are designed to perform specific functions and therefore have specific properties that could potentially be harmful. Nanoparticles such as titanium dioxide have the potential to become transparent and are therefore widely...

  15. Ex situ integration of iron oxide nanoparticles onto the exfoliated expanded graphite flakes in water suspension

    Directory of Open Access Journals (Sweden)

    Jović Nataša

    2014-01-01

    Full Text Available Hybrid structures composed of exfoliated expanded graphite (EG and iron oxide nanocrystals have been produced by an ex situ process. The iron oxide nanoparticles coated with meso-2,3-dimercaptosuccinic acid (DMSA, or poly(acrylic acid (PAA were integrated onto the exfoliated EG flakes by mixing their aqueous suspensions at room temperature under support of 1-ethyl-3-(3-dimethylaminopropylcarbodiimide (EDC and N-hydroxysuccin-nimide (NHS. EG flakes have been used both, naked and functionalized with branched polyethylenimine (PEI. Complete integration of two constituents has been achieved and mainteined stable for more than 12 months. No preferential spatial distribution of anchoring sites for attachement of iron oxide nanoparticles has been observed, regardless EG flakes have been used naked or functionalized with PEI molecules. The structural and physico-chemical characteristics of the exfoliated expanded graphite and its hybrids nanostructures has been investigated by SEM, TEM, FTIR and Raman techniques. [Projekat Ministarstva nauke Republike Srbije, br. 45015

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-15

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

  18. Uptake, accumulation, and biotransformation of metal oxide nanoparticles by a marine suspension-feeder

    Energy Technology Data Exchange (ETDEWEB)

    Montes, Milka O. [University of California Center for Environmental Implications of Nanotechnology, Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106 (United States); University of Texas of the Permian Basin, 4901 E. University, Odessa, TX 79762 (United States); Hanna, Shannon K.; Lenihan, Hunter S. [University of California Center for Environmental Implications of Nanotechnology, Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106 (United States); Keller, Arturo A., E-mail: keller@bren.ucsb.edu [University of California Center for Environmental Implications of Nanotechnology, Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106 (United States)

    2012-07-30

    Highlights: Black-Right-Pointing-Pointer Suspension-feeding by mussels can greatly alter mobility and fate of metal oxide nanoparticles. Black-Right-Pointing-Pointer Bioprocessing of metal oxide nanoparticles by mussels removes large fraction from water column. Black-Right-Pointing-Pointer Mussels repackage metal oxide nanoparticles in highly concentrated pseudofeces. Black-Right-Pointing-Pointer Novel biological pathway between major compartments in marine systems. Black-Right-Pointing-Pointer Very different outcome for ZnO and CeO{sub 2} nanoparticles based on their solubility. - Abstract: A growing body of evidence indicates that some engineered nanoparticles (ENPs) are toxic to organisms that perform important ecosystem services in terrestrial and aquatic ecosystems. However, toxicity can be influenced by the biotransformation of contaminants, including ENPs, as it may alter the fate and transport of these substances. In turn, fate and transport can influence their bioavailability. To understand how biotransformation influences the fate and transport of ENPs in marine ecosystems, we exposed suspension-feeding mussels, Mytilus galloprovincialis, to two common nano-metal oxides, CeO{sub 2} and ZnO, over a range of concentrations from 1 mg L{sup -1} to 10 mg L{sup -1}, in a laboratory experiment. Mussels exposed to 10 mg L{sup -1} accumulated 62 {mu}g g{sup -1} of Ce and 880 {mu}g g{sup -1} of Zn on a dry tissue basis but rejected 21,000 {mu}g g{sup -1} for Ce and 63,000 {mu}g g{sup -1} for Zn in pseudofeces. Scanning electron microscope evidence indicates CeO{sub 2} remained as ENPs but ZnO did not after being rejected by the mussels. Mussels filtered most of the CeO{sub 2} from the aqueous media, while a significant fraction of Zn remained in solution. Differences in ENP solubility affect ENP uptake, excretion, and accumulation in mussels. Our study highlights the potential role of marine suspension feeders in biotransformation of ENPs.

  19. Characterisation of the de-agglomeration effects of bovine serum albumin on nanoparticles in aqueous suspension.

    Science.gov (United States)

    Tantra, Ratna; Tompkins, Jordan; Quincey, Paul

    2010-01-01

    This paper describes the use of nanoparticle characterisation tools to evaluate the interaction between bovine serum albumin (BSA) and dispersed nanoparticles in aqueous media. Dynamic light scattering, zeta-potential measurements and scanning electron microscopy were used to probe the state of zinc oxide (ZnO) and titanium dioxide (TiO(2)) nanoparticles in the presence of various concentrations of BSA, throughout a three-day period. BSA was shown to adhere to ZnO but not to TiO(2). The adsorption of BSA led to subsequent de-agglomeration of the sub-micron ZnO clusters into smaller fragments, even breaking them up into individual isolated nanoparticles. We propose that certain factors, such as adsorption kinetics of BSA on to the surface of ZnO, as well as the initial agglomerated state of the ZnO, prior to BSA addition, are responsible for promoting the de-agglomeration process. Hence, in the case of TiO(2) we see no de-agglomeration because: (a) the nanoparticles are more highly agglomerated to begin with and (b) BSA does not adsorb effectively on the surface of the nanoparticles. The zeta-potential results show that, for either ZnO or TiO(2), the presence of BSA resulted in enhanced stability. In the case of ZnO, the enhanced stability is limited to BSA concentrations below 0.5 wt.%. Steric and electrostatic repulsion are thought to be responsible for improved stability of the dispersion.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  2. Photocatalytic selective oxidation of phenol in suspensions of titanium dioxide with exposed {0 0 1} facets

    International Nuclear Information System (INIS)

    Ye, Hengpeng; Lu, Shaoming

    2013-01-01

    Anatase TiO 2 nanocrystals with exposed {0 0 1} facets were tailored by hydrothermal treatment of Ti(OC 4 H 9 ) 4 –HF–H 2 O mixed solution. The photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption–desorption isotherms and X-ray photoelectron spectroscopy (XPS). The effect of structure of the photocatalyst on the photocatalytic selective oxidation of phenol under UV irradiation was studied. The experiment results showed that (1) the percentage of the exposed {0 0 1} facets of the nanocrystal increases with increasing the nominal atomic ratio of fluorine to titanium (R F ), (2) catechol and hydroquinone are main intermediates detected during photocatalytic oxidation of phenol, and (3) both photocatalytic oxidation of phenol and selectivity (yield) of catechol are positively correlated with the percentage of exposed {0 0 1} facets of the high-energy TiO 2 nanocrystals. The enhanced conversion of phenol and selectivity (yield) of catechol were ascribed to the synergistic effects of the exposed high-energy {0 0 1} facets and surface fluorination. This study may provide new insight into the selective oxidation of organics.

  3. Biosynthesis and characterization of zinc, magnesium and titanium nanoparticles: an eco-friendly approach

    Science.gov (United States)

    Raliya, Ramesh; Tarafdar, J. C.

    2014-02-01

    In the present study, zinc (Zn), magnesium (Mg) and titanium (Ti) nanoparticles synthesized using fungus by employing various precursor salts of sulfate salts, nitrate salts, chloride salts and oxide salts. To access the nanoparticle production potential, over a hundreds of fungi were isolated from the soil and tested with precursor salts of the Zn, Mg and Ti. Out of which, only 14 fungal isolates were identified, having potential to reduce metal salt into metal nanoparticles. Upon molecular identification, six were identified as Aspergillus flavus, two each as Aspergillus terreus and Aspergillus tubingensis and one each as Aspergillus niger, Rhizoctonia bataticola, Aspergillus fumigatus, and Aspergillus oryzae. Factors responsible for more production of monodispersed Zn, Mg and Ti nanoparticles were optimized. It was concluded that 0.01 mM precursor salt concentration, 72 h of incubation at pH 5.5 and temperature 28 °C resulted smaller nanoparticles obtained. The biosynthesized functional Zn and Ti nanoparticles can be stored up to 90 days and Mg nanoparticles up to 105 days in its nanoform. Bio-transformed products were analyzed using valid characterization technique i.e. dynamic light scattering, transmission electron microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy to confirm size, shape, surface morphology and elemental composition. It was found that the average size of developed nano Zn was 8.2 nm, with surface charge of -5.70 mV and 98 % particles were of Zn metal only. Similarly, the average size of Mg nanoparticles was 6.4 nm with surface charge of -6.66 and 97.4 % Mg metal yield, whereas, Ti nanoparticles size were found in the ranges between 1.5 and 30 nm with surface charge of -6.25 mV and 98.6 % Ti metal yield.

  4. Photocatalytic inactivation of bacteria from spoiled raw chicken carcasses in aqueous suspensions by TiO2 nanoparticles

    Science.gov (United States)

    Bacterial spoilage is a major cause of reduced shelf life of fresh poultry; therefore, decreasing contamination by spoilage bacteria could increase the shelf life of these products. Titanium dioxide (TiO2) nanoparticles in the presence of UVA light possess antibacterial activities towards several ba...

  5. Ionic Liquid-Tethered Nanoparticle Suspensions: A Novel Class of Ionogels

    KAUST Repository

    Moganty, Surya S.

    2012-04-10

    We report a novel class of silica ionogels created by dispersing silica nanoparticles densely grafted with the ionic liquid (IL) 1-trimethoxysilyl propyl-3-methyl-imidazolium bis- (trifluoromethylsulfonyl) imide (SpmImTSFI) in a 1-butyl-3- methyl-pyrrolidinium bis(trifluoromethylsulfonyl) imide (BmpyrTFSI) IL host. We find that over the entire range of nanoparticle volume fractions studied the systems exist as stable suspensions of SiO 2-SpmImTFSI in the BmpyrTFSI host. Remarkably, we also find that addition of even minute quantities of SiO 2-SpmImTFSI to the BmpyrTFSI IL suppresses crystallization of the host. The resulting disordered hybrid fluids exhibit liquid-like transport properties over a vastly extended temperature range; they open the way for facile synthesis of ILs with extended operating temperature windows. These observations are explained in terms of ionic coupling of the nanoparticle-tethered and free TFSI anions, which is thought to suppress crystallization of BmpyrTFSI. © 2012 American Chemical Society.

  6. Effect of Nitric Acid Concentrations on Synthesis and Stability of Maghemite Nanoparticles Suspension

    Directory of Open Access Journals (Sweden)

    Irwan Nurdin

    2014-01-01

    Full Text Available Maghemite (γ-Fe2O3 nanoparticles have been synthesized using a chemical coprecipitation method at different nitric acid concentrations as an oxidizing agent. Characterization of all samples performed by several techniques including X-ray diffraction (XRD, transmission electron microscopy (TEM, alternating gradient magnetometry (AGM, thermogravimetric analysis (TGA, dynamic light scattering (DLS, and zeta potential. The XRD patterns confirmed that the particles were maghemite. The crystallite size of all samples decreases with the increasing concentration of nitric acid. TEM observation showed that the particles have spherical morphology with narrow particle size distribution. The particles showed superparamagnetic behavior with decreased magnetization values at the increasing concentration of nitric acid. TGA measurement showed that the stability temperature decreases with the increasing concentration of nitric acid. DLS measurement showed that the hydrodynamic particle sizes decrease with the increasing concentration of nitric acid. Zeta potential values show a decrease with the increasing concentration of nitric acid. The increasing concentration of nitric acid in synthesis of maghemite nanoparticles produced smaller size particles, lower magnetization, better thermal stability, and more stable maghemite nanoparticles suspension.

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

    International Nuclear Information System (INIS)

    Babitha, S; Korrapati, Purna Sai

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-15

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

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

    Science.gov (United States)

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

    2014-09-15

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

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

    Directory of Open Access Journals (Sweden)

    Vaishaali Natarajan

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

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  12. Electrical pulse – mediated enhanced delivery of silver nanoparticles into living suspension cells for surface enhanced Raman spectroscopy

    International Nuclear Information System (INIS)

    Lin, J; Li, B; Feng, S; Chen, G; Li, Y; Huang, Z; Chen, R; Yu, Y; Huang, H; Lin, S; Li, C; Su, Y; Zeng, H

    2012-01-01

    Electrical pulse-mediated enhanced silver nanoparticles delivery is a much better method for intracellular surface-enhanced Raman spectroscopy (SERS) measurements of suspension cells. Robust and high-quality SERS spectra of living suspension cells were obtained based on an electroporation-SERS method, which can overcomes the shortcoming of non-uniform distribution of silver nanoparticles localized in the cell cytoplasm after electroporation and reduces the amount variance of silver nanoparticles delivered into different cells. The electroporation parameters include three 150 V (375 V/cm) electric pulses of 1, 5, and 5 ms durations respectively. Our results indicate that considerable amount of silver nanoparticles can be rapidly delivered into the human promyelocytic leukemia HL60 cells, and the satisfied SERS spectra were obtained while the viability of the treated cells was highly maintained (91.7%). The electroporation-SERS method offers great potential approach in delivering silver nanoparticles into living suspension cells, which is useful for widely biomedical applications including the real-time intracellular SERS analysis of living cells

  13. Magnetic field analysis in a suspension of gyrotactic microorganisms and nanoparticles over a stretching surface

    Energy Technology Data Exchange (ETDEWEB)

    Akbar, Noreen Sher, E-mail: noreensher@yahoo.com [DBS& H, CEME, National University of Sciences and Technology, Islamabad (Pakistan); Khan, Zafar Hayat [Department of Mathematics, University of Malakand, Dir (Lower), Khyber Pakhtunkhwa (Pakistan)

    2016-07-15

    The combine effects of magnetic field bioconvection, Brownian motion and thermophoresis on a free convection nanofluid flow over a stretching sheet containing gyrotactic microorganisms are investigated. The self-similar Buongiorno model is analyzed first time for stretching sheet numerically. The present results are compared with available data and are found in an excellent agreement. Pertinent results are presented graphically and discussed quantitatively with respect to variation in bioconvection parameters. - Highlights: • Two dimensional MHD flow in a suspension of gyrotactic microorganisms and nanoparticles over a stretching surface is discussed first paper in literature. • Governed problem for proposed model solved numerically using fourth-order Runge–Kutta–Fehlberg method. • Good agreement in comparison with previous studies. • Tabulated physical quantities and graphics of all flow profiles. • Graphics of reduced skin friction coefficient, when the different flow parameters vary.

  14. Lowering of the cavitation threshold in aqueous suspensions of porous silicon nanoparticles for sonodynamic therapy applications

    Energy Technology Data Exchange (ETDEWEB)

    Sviridov, A. P., E-mail: asagittarius89@gmail.com; Osminkina, L. A. [Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Nikolaev, A. L. [Faculty of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Kudryavtsev, A. A. [Institute of Theoretical and Experimental Biophysics, Russian Academy of Science, 142290 Pushino, Moscow Region (Russian Federation); Vasiliev, A. N. [Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Theoretical Physics and Applied Mathematics Department, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Timoshenko, V. Yu. [Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Tomsk State University, 634050 Tomsk (Russian Federation)

    2015-09-21

    A significant decrease of the cavitation threshold in aqueous suspensions of porous silicon nanoparticles (PSi NPs) with sizes about 100 nm as compared with pure water was observed for ultrasound irradiation (USI) with therapeutic frequency (0.88 MHz) and intensities (about 1 W/cm{sup 2}). This effect is explained by porous morphology of PSi NPs, which promotes the nucleation of cavitation bubbles. In vitro experiments revealed a suppression of the proliferation of cancer cells with the introduced PSi NPs after exposure to USI related to the enhanced cavitation processes, which led to the cell destruction. The obtained results demonstrate that PSi NPs are prospective for applications as sonosensitizers in mild cancer therapy.

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

    Science.gov (United States)

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

    2015-10-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2017-07-01

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

  18. Just add water: reproducible singly dispersed silver nanoparticle suspensions on-demand

    International Nuclear Information System (INIS)

    MacCuspie, Robert I.; Allen, Andrew J.; Martin, Matthew N.; Hackley, Vincent A.

    2013-01-01

    Silver nanoparticles (AgNPs) are of interest due to their antimicrobial attributes, which are derived from their inherent redox instability and subsequent release of silver ions. At the same time, this instability is a substantial challenge for achieving stable long-term storage for on-demand use of AgNPs. In this study, we describe and validate a “just add water” approach for achieving suspensions of principally singly dispersed AgNPs. By lyophilizing (freeze drying) the formulated AgNPs into a solid powder, or cake, water is removed thereby eliminating solution-based chemical changes. Storing under inert gas further reduces surface reactions such as oxidation. An example of how to optimize a lyophilization formulation is presented, as well as example formulations for three AgNP core sizes. This “just add water” approach enables ease of use for the researcher desiring on-demand singly dispersed AgNP suspensions from a single master batch. Implementation of this methodology will enable studies to be performed over long periods of time and across different laboratories using particles that are identical chemically and physically and available on-demand. In addition, the approach of freeze drying and on-demand reconstitution by adding water has enabled the development of AgNP reference materials with the required shelf-life stability, one of the principal objectives of this research

  19. Solvent-mediated pathways to gelation and phase separation in suspensions of grafted nanoparticles

    KAUST Repository

    Anyfantakis, Manos

    2009-01-01

    We explore the role of the solvent medium on the interplay between gelation and phase separation in suspensions of organosilicate planar hybrids grafted with hydrocarbon chains. We establish their phase diagram by means of dynamic light scattering, rheology and visual observations, and different routes to gelation, depending on the solvent used. In agreement with earlier works, the solvent quality for the grafted chains at a given temperature controls the balance between attractions and repulsions, and hence the phase diagram of the nanoparticles and their tendency to gel. Here we show how to tune the suspension state and hence its rheology. For decane, a good solvent for the hydrocarbon chains, gelation occurs at rather low volume fractions in the presence of phase separation. This is due to the interdigitation of solvent molecules with the grafted chains, resulting in their crystalline packing that promotes the attraction between particles. For toluene, a solvent of reduced quality for the hydrocarbon chains, no interdigitation takes place, and hence gelation is triggered by clustering at higher volume fractions before phase separation. Our results support the generic picture of complex kinetic arrest/phase separation interplay in soft matter, where phase separation can proceed, be interrupted or be completely inhibited. A number of interesting possibilities for tailoring the rheology of grafted colloidal systems emerge. © 2009 The Royal Society of Chemistry.

  20. The fluorescence quenching mechanism of coumarin 120 with CdS nanoparticles in aqueous suspension

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Murat; Bozkurt, Ebru; Meral, Kadem; Arık, Mustafa; Onganer, Yavuz, E-mail: yonganer@atauni.edu.tr

    2015-01-15

    The interaction of coumarin 120 (C120) with CdS nanoparticles (CdS NPs) in aqueous suspension was examined by using UV–vis absorption, steady-state, time-resolved fluorescence, and electron paramagnetic resonance (EPR) spectroscopy techniques. The fluorescence intensity of C120 was quenched with increasing the amount of CdS NPs in the aqueous suspension. The spectroscopic data revealed that the C120 molecules adsorbed on CdS NPs via electrostatic interactions. The apparent association constant (K{sub app}) and the degree of association (α) for C120/CdS NPs were determined as 130.3 M{sup −1} and 0.51 for 4 nm CdS NPs and 624.3 M{sup −1} and 0.71 for 8 nm CdS NPs, respectively. The photoinduced EPR studies exhibited that no electron transfers between CdS and C120 taking place. The results revealed that the fluorescence quenching of C120 with different CdS NPs is due to the formation of a non-fluorescent complex. - Highlights: • Interaction of C120 with CdS NPs in aqueous solution was spectroscopically examined. • Nonfluorescent C120–CdS NPs complexes in aqueous solution were formed. • In the system, CdS NPs in aqueous solution acted as a fluorescence quencher.

  1. The fluorescence quenching mechanism of coumarin 120 with CdS nanoparticles in aqueous suspension

    International Nuclear Information System (INIS)

    Acar, Murat; Bozkurt, Ebru; Meral, Kadem; Arık, Mustafa; Onganer, Yavuz

    2015-01-01

    The interaction of coumarin 120 (C120) with CdS nanoparticles (CdS NPs) in aqueous suspension was examined by using UV–vis absorption, steady-state, time-resolved fluorescence, and electron paramagnetic resonance (EPR) spectroscopy techniques. The fluorescence intensity of C120 was quenched with increasing the amount of CdS NPs in the aqueous suspension. The spectroscopic data revealed that the C120 molecules adsorbed on CdS NPs via electrostatic interactions. The apparent association constant (K app ) and the degree of association (α) for C120/CdS NPs were determined as 130.3 M −1 and 0.51 for 4 nm CdS NPs and 624.3 M −1 and 0.71 for 8 nm CdS NPs, respectively. The photoinduced EPR studies exhibited that no electron transfers between CdS and C120 taking place. The results revealed that the fluorescence quenching of C120 with different CdS NPs is due to the formation of a non-fluorescent complex. - Highlights: • Interaction of C120 with CdS NPs in aqueous solution was spectroscopically examined. • Nonfluorescent C120–CdS NPs complexes in aqueous solution were formed. • In the system, CdS NPs in aqueous solution acted as a fluorescence quencher

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

    Directory of Open Access Journals (Sweden)

    Dessy Ariyanti

    2016-03-01

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

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

    NARCIS (Netherlands)

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

    2014-01-01

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

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  5. Contribution to the study of the physical stability of the suspensions of zinc oxide, titanium dioxide and precipitated sulphur employing emulsified solid greases like vehicle

    International Nuclear Information System (INIS)

    Porras Navarro, Martha

    2001-01-01

    This research evaluated the physical stability of the suspensions of zinc oxide, precipitated sulphur and titanium dioxide. By using emulsified vehicles of three solid greases: stearilic alcohol, stearic acid and beeswax. That varies the concentration of solid grease (2%, 4%, 6 %) and the velocity of agitation for the emulsified vehicle's preparation (250, 500, 750 revolutions by minutes). That got 81 suspensions, 27 for every grease employed. The following effects there were evaluated like indicators of the physical stability of the suspensions: volume of sediment, apparent viscosity, facility of resuspension. There was effected an analysis of the varying of two controlled factors to establish the importance since the statistical viewpoint of the variants of the process over the volume of the sediment. This study indicates that the selection of solid grease is an parameter which influence is significant, what supports the got data through the research. By giving as a result that the stearilic alcohol is the most competent vehicle for the preparation of these suspensions. (Author) [es

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Farzin Heravi

    2013-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

    Jovanović, Boris; Guzmán, Héctor M

    2014-06-01

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

  12. Aggregation and transport of rutile titanium dioxide nanoparticles with montmorillonite and diatomite in the presence of phosphate in porous sand.

    Science.gov (United States)

    Guo, Peng; Xu, Nan; Li, Duo; Huangfu, Xinxing; Li, Zuling

    2018-08-01

    Crop soil is inevitably contaminated by the excess of phosphate (P) fertilizers. A large amount of nanoparticle titanium dioxide (nTiO 2 ) entered soils as well due to the wide use of engineered nanomaterials. It is of great urgency and a high priority to investigate the mechanisms of nTiO 2 deposition with the presence of P in crop soils. This study investigated the transport behavior of (1.0 g L -1 ) rutile nTiO 2 with two representative clay particles (montmorillonite or diatomite) in the presence of P through the saturated quartz sand. In 10 mM NaCl electrolyte solution at pH 6.0, the recovery percentage of nTiO 2 was 36.3% from sand column. Nevertheless, it was reduced to 18.6% and 11.1% while montmorillonite and diatomite present in suspensions, respectively. Obviously, the improvement of nTiO 2 retention in sand was more pronounced by diatomite than montmorillonite. The likely mechanism for this result was that large aggregates were formed due to the attachment of nTiO 2 to montmorillonite and diatomite. Moreover, the surface of diatomite with the larger hydrodynamic radius was less negatively charged by comparison with montmorillonite. However, this phenomenon disappeared with the addition of P. P adsorption increases the repulsive force between particles and sand and the fast release of attached nTiO 2 -montmorillonite and diatomite from sand. The two-site kinetic retention model and the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory suggested that the combination of k 1/ k 1d , k 2 and secondary minimum energy can be used to accurately describe the attachment of nTiO 2 -montmorillonite and diatomite to sand in the presence of P. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

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

  14. Isotope effect in heavy/light water suspensions of optically active gold nanoparticles

    Science.gov (United States)

    Kutsenko, V. Y.; Artykulnyi, O. P.; Petrenko, V. I.; Avdeev, M. V.; Marchenko, O. A.; Bulavin, L. A.; Snegir, S. V.

    2018-04-01

    Aqueous suspensions of optically active gold nanoparticles coated with trisodium citrate were synthesized in light (H2O) water and mixture of light and heavy (H2O/D2O) water using the modified Turkevich protocol. The objective of the paper was to verify sensitivity of neutron scattering methods (in particular, neutron reflectometry) to the potential isotope H/D substitution in the stabilizing organic shell around particles in colloidal solutions. First, the isotope effect was studied with respect to the changes in the structural properties of metal particles (size, shape, crystalline morphology) in solutions by electron microscopy including high-resolution transmission electron microscopy from dried systems. The structural factors determining the variation in the adsorption spectra in addition to the change in the optical properties of surrounding medium were discussed. Then, neutron reflectometry was applied to the layered nanoparticles anchored on a silicon wafer via 3-aminopropyltriethoxysilane molecules to reveal the presence of deuterated water molecules in the shell presumably formed by citrate molecules around the metallic core.

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

    Science.gov (United States)

    Buzby, Scott Edward

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2018-09-01

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

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

    Directory of Open Access Journals (Sweden)

    James C K Lai

    2008-12-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    KAUST Repository

    Ismail, Mohamed

    2016-05-04

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

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

    Science.gov (United States)

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

    2015-02-01

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

  2. Synthesis and characterization of Tin / Titanium mixed oxide nanoparticles doped with lanthanide for biomarking

    International Nuclear Information System (INIS)

    Paganini, Paula Pinheiro

    2012-01-01

    This work presents the synthesis, characterization and photo luminescent study of tin and titanium mixed oxide nanoparticles doped with europium, terbium and neodymium to be used with luminescent markers on biological systems. The syntheses were done by co-precipitation, protein sol-gel and Pechini methods and the nanoparticles were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction and X-ray absorption spectroscopy. The photo luminescent properties studies were conducted for luminophores doped with europium, terbium and neodymium synthesized by coprecipitation method. For luminophore doped with europium it was possible to calculate the intensity parameters and quantum yield and it showed satisfactory results. In the case of biological system marking it was necessary the functionalization of these particles to allow them to bind to the biological part to be studied. So the nanoparticles were functionalized by microwave and Stöber methods and characterized by infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction obtaining qualitative response of functionalization efficacy. The ninhydrin spectroscopic method was used for quantification of luminophores functionalization. The photo luminescent studies of functionalized particles demonstrate the potential applying of these luminophores as luminescent markers. (author)

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

    Science.gov (United States)

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

    2016-11-01

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

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

    Science.gov (United States)

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

    2018-05-01

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

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

    Science.gov (United States)

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-04-15

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

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

    Science.gov (United States)

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

    2017-04-01

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

  8. ROS enhancement by silicon nanoparticles in X-ray irradiated aqueous suspensions and in glioma C6 cells

    International Nuclear Information System (INIS)

    David Gara, Pedro M.; Garabano, Natalia I.; Llansola Portoles, Manuel J.; Moreno, M. Sergio; Dodat, Diego; Casas, Oscar R.; Gonzalez, Mónica C.; Kotler, Mónica L.

    2012-01-01

    The capability of silicon nanoparticles to increase the yield of reactive species upon 4 MeV X-ray irradiation of aqueous suspensions and C6 glioma cell cultures was investigated. ROS generation was detected and quantified using several specific probes. The particles were characterized by FTIR, XPS, TEM, DLS, luminescence, and adsorption spectroscopy before and after irradiation to evaluate the effect of high energy radiation on their structure. The total concentration of O 2 •− /HO 2 • , HO • , and H 2 O 2 generated upon 4-MeV X-ray irradiation of 6.4 μM silicon nanoparticle aqueous suspensions were on the order of 10 μM per Gy, ten times higher than that obtained in similar experiments but in the absence of particles. Cytotoxic 1 O 2 was generated only in irradiation experiments containing the particles. The particle surface became oxidized to SiO 2 and the luminescence yield reduced with the irradiation dose. Changes in the surface morphology did not affect, within the experimental error, the yields of ROS generated per Gy. X-ray irradiation of glioma C6 cell cultures with incorporated silicon nanoparticles showed a marked production of ROS proportional to the radiation dose received. In the absence of nanoparticles, the cells showed no irradiation-enhanced ROS generation. The obtained results indicate that silicon nanoparticles of 1 O 2 upon X-ray irradiation opens novel approaches in the design of therapy strategies.

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

    Directory of Open Access Journals (Sweden)

    Nur Hamidah Abdul Halim

    2017-09-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2016-12-01

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

  12. Reduced bacteria adhesion on octenidine loaded mesoporous silica nanoparticles coating on titanium substrates.

    Science.gov (United States)

    Xu, Gaoqiang; Shen, Xinkun; Dai, Liangliang; Ran, Qichun; Ma, Pingping; Cai, Kaiyong

    2017-01-01

    Bacterial infection is one of the most severe postoperative complications leading to implantation failure. The early bacterial stage (4-6h) was proved to be the "decisive period" for long-term bacteria-related infection. Thus, to endow potential early antibacterial capacity for a titanium (Ti) based implant, an effective antiseptic agent of octenidine dihydrochloride (OCT) was effectively loaded on the mesoporous silica nanoparticles (MSNs)-incorporated titania coating which was fabricated by an electrophoretic-enhanced micro-arc oxidation technique. The surface characteristic of the coatings were characterized by various methods (SEM, AFM, XPS, XRD, etc.), and its corrosion resistance was also examined by the potentiodynamic polarization curves. The composite coating without OCT loading not only displayed good cytocompatibility but also exhibited certain anti-bacterial property. After loading with OCT, its antibacterial efficiency of the titanium substrates with composite coating was greatly enhanced without compromising their cytocompatibility. The study provides an approach for the fabrication of anti-bacterial Ti implant for potential orthopedic application. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2015-04-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

  15. Novel titanium oxide nanoparticles for effective delivery of paclitaxel to human breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Mund, R., E-mail: rachnamund@gmail.com; Panda, N., E-mail: niladri1panda@gmail.com [National Institute of Technology, Department of Biotechnology and Medical Engineering (India); Nimesh, S., E-mail: surendranimesh@curaj.ac.in [Central University of Rajasthan, Department of Biotechnology, School of Life Sciences (India); Biswas, A., E-mail: amitb79@gmail.com [National Institute of Technology, Department of Biotechnology and Medical Engineering (India)

    2014-12-15

    Novel titanium oxide (TiO{sub 2}) nanoparticles were fabricated via a modified propanol drying step. These nanoparticles were loaded with anti-cancer drug paclitaxel (PTX) to yield PTX-TiO{sub 2} nanocomposites. The nanocomposites were characterized for their size and surface morphology employing nanoparticle tracking analysis (NTA) and scanning electron microscopy (SEM). The SEM images showed spherical particles with smooth surface and narrow size distribution of ∼30–40 nm, which was also supported by NTA analysis data. The drug loading efficiency of the air-dried nanoparticles was observed to be ∼63.61 % while those prepared through propanol-induced drying step showed ∼69.70 %, thereby demonstrating higher efficiency of the latter. In vitro pH-dependent release of the loaded PTX was observed with higher release at acidic pH compared with physiological pH. Cell uptake studies suggested of time-dependent internalization of nanocomposites with significant improvement in uptake by increasing incubation time from 2 to 24 h, as evidenced by flow cytometry. Further, the cell viability as a measure of anti-cancer activity revealed that cell viability upon exposure to PTX only was 40.5 % while that of PTX-TiO{sub 2} nanocomposite showed 21.6 % viability after 24 h, suggesting better anti-cancer efficacy of nanocomposites. Apoptosis studies revealed that cells treated with PTX-TiO{sub 2} nanocomposites possessed more amount of apoptotic bodies as compared to those treated with PTX only.

  16. Optical filter based on Fabry-Perot structure using a suspension of goethite nanoparticles as electro-optic material

    Science.gov (United States)

    Abbas, Samir; Dupont, Laurent; Dozov, Ivan; Davidson, Patrick; Chanéac, Corinne

    2018-02-01

    We have investigated the feasibility of optical tunable filters based on a Fabry-Perot etalon that uses a suspension of goethite (α-FeOOH) nanorods as electro-optic material for application in optical telecommunications in the near IR range. These synthetic nanoparticles have a high optical anisotropy that give rise to a very strong Kerr effect in their colloidal suspensions. Currently, these particles are dispersed in aqueous solvent, with pH2 to ensure the colloidal electrostatic stability. However, the high conductivity of these suspensions requires using high-frequency electric fields (f > 1 MHz), which brings about a high power consumption of the driver. To decrease the field frequency, we have changed the solvent to ethylene glycol which has a lower electrical conductivity than the aqueous solvent. We have built a Fabry-Perot cell, filled with this colloidal suspension in the isotropic phase, and showed that a phase shift of 14 nm can be obtained in a field of 3V/μm. Therefore, the device can operate as a tunable filter. A key advantage of this filter is that it is, by principle, completely insensitive to the polarization of the input light. However, several technological issues still need to be solved, such as ionic contamination of the suspension from the blocking layers, and dielectrophoretic and thermal effects.

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

    Science.gov (United States)

    Khan, Razia; Fulekar, M H

    2016-08-01

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

  18. Modelling approaches to the dewetting of evaporating thin films of nanoparticle suspensions

    International Nuclear Information System (INIS)

    Thiele, U; Vancea, I; Archer, A J; Robbins, M J; Frastia, L; Stannard, A; Pauliac-Vaujour, E; Martin, C P; Blunt, M O; Moriarty, P J

    2009-01-01

    We review recent experiments on dewetting thin films of evaporating colloidal nanoparticle suspensions (nanofluids) and discuss several theoretical approaches to describe the ongoing processes including coupled transport and phase changes. These approaches range from microscopic discrete stochastic theories to mesoscopic continuous deterministic descriptions. In particular, we describe (i) a microscopic kinetic Monte Carlo model, (ii) a dynamical density functional theory and (iii) a hydrodynamic thin film model. Models (i) and (ii) are employed to discuss the formation of polygonal networks, spinodal and branched structures resulting from the dewetting of an ultrathin 'postcursor film' that remains behind a mesoscopic dewetting front. We highlight, in particular, the presence of a transverse instability in the evaporative dewetting front, which results in highly branched fingering structures. The subtle interplay of decomposition in the film and contact line motion is discussed. Finally, we discuss a simple thin film model (iii) of the hydrodynamics on the mesoscale. We employ coupled evolution equations for the film thickness profile and mean particle concentration. The model is used to discuss the self-pinning and depinning of a contact line related to the 'coffee-stain' effect. In the course of the review we discuss the advantages and limitations of the different theories, as well as possible future developments and extensions.

  19. Bioaccumulation and Toxicity of Carbon Nanoparticles Suspension Injection in Intravenously Exposed Mice

    Directory of Open Access Journals (Sweden)

    Ping Xie

    2017-11-01

    Full Text Available Carbon nanoparticles suspension injection (CNSI has been widely used in tumor drainage lymph node mapping, and its new applications in drug delivery, photothermal therapy, and so on have been extensively investigated. To develop new clinical applications, the toxicity of CNSI after intravenous exposure should be thoroughly investigated to ensure its safe use. Herein, we studied the bioaccumulation of CNSI in reticuloendothelial system (RES organs and the corresponding toxicity to mice. After the intravenous injection of CNSI, no abnormal behavior of mice was observed during the 28-day observation period. The body weight increases were similar among the exposed groups and the control group. The parameters of hematology and serum biochemistry remained nearly unchanged, with very few of them showing significant changes. The low toxicity of CNSI was also reflected by the unchanged histopathological characteristics of these organs. The injection of CNSI did not induce higher apoptosis levels either. The slight oxidative stress was observed in RES organs at high dosages at day 7 post-exposure. The implication to the clinical applications and toxicological evaluations of carbon nanomaterials is discussed.

  20. Decolorization of methylene blue in aqueous suspensions of gold nanoparticles using parallel nanosecond pulsed laser.

    Science.gov (United States)

    Zong, Yan P; Liu, Xian H; Du, Xi W; Lu, Yi R; Wang, Mei Y; Wang, Guang Y

    2013-01-01

    Using 532 nm parallel nanosecond pulsed laser, the decolorization of methylene blue (MB) in aqueous suspensions of gold nanoparticles (GNPs) was studied. The effects of various experimental parameters, such as irradiation time, laser energy, and initial MB concentration on the decolorization rate were investigated. Experiments using real samples of textile dyeing wastewater were also carried out to examine the effectiveness of the method in more complex samples. From the results, the following conclusions may be drawn: (i) Under the optimum conditions (pH 7.19, 135 mJ laser energy, 4 mg/L MB concentration, and 11.6 mg/L GNP concentration), the rate of MB decolorization could reach 94% in 15 min. The decolorization follows pseudo-first-order kinetics; (ii) The amount of MB decreased rapidly during the decolorization. No intermediates of the decolorization could be detected by high-performance liquid chromatography. These observations indicate that MB was decolorized through a very rapid degradation mechanism; (iii) The rate of MB decolorization increased with the increase in laser energy (at laser energies of 0 to 135 mJ); and, (iv) The efficient decolorization of MB in real samples of textile dyeing wastewater was achieved at a decolorization rate of about 85% in 15 min.

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

    Science.gov (United States)

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

    2014-07-09

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

  2. Tuning the Electronic Structure of Titanium Oxide Support to Enhance the Electrochemical Activity of Platinum Nanoparticles

    KAUST Repository

    Shi, Feifei

    2013-09-11

    Two times higher activity and three times higher stability in methanol oxidation reaction, a 0.12 V negative shift of the CO oxidation peak potential, and a 0.07 V positive shift of the oxygen reaction potential compared to Pt nanoparticles on pristine TiO2 support were achieved by tuning the electronic structure of the titanium oxide support of Pt nanoparticle catalysts. This was accomplished by adding oxygen vacancies or doping with fluorine. Experimental trends are interpreted in the context of an electronic structure model, showing an improvement in electrochemical activity when the Fermi level of the support material in Pt/TiOx systems is close to the Pt Fermi level and the redox potential of the reaction. The present approach provides guidance for the selection of the support material of Pt/TiOx systems and may be applied to other metal-oxide support materials, thus having direct implications in the design and optimization of fuel cell catalyst supports. © 2013 American Chemical Society.

  3. pH-regulated antimony oxychloride nanoparticle formation on titanium oxide nanostructures: a photocatalytically active heterojunction

    KAUST Repository

    Buchholcz, Balázs

    2017-02-06

    Improving the catalytic activity of heterogeneous photocatalysts has become a hot topic recently. To this end, considerable progress has been made in the efficient separation of photogenerated charge carriers by e.g. the realization of heterojunction photocatalysts. V-VI-VII compound semiconductors, namely, bismuth oxyhalides, are popular photocatalysts. However, results on antimony oxyhalides [SbOX (X = Br, Cl, I)], the very promising alternatives to the well-known BiOX photomodifiers, are scarce. Here, we report the successful decoration of titanium oxide nanostructures with 8-11 nm diameter SbOX nanoparticles for the first time ever. The product size and stoichiometry could be controlled by the pH of the reactant mixture, while subsequent calcination could transform the structure of the titanate nanotube (TiONT) support and the prepared antimony oxychloride particles. In contrast to the ease of composite formation in the SbOX/TiONT case, anatase TiO could not facilitate the formation of antimony oxychloride nanoparticles on its surface. The titanate nanotube-based composites showed activity in a generally accepted quasi-standard photocatalytic test reaction (methyl orange dye decolorization). We found that the SbOCl/TiONT synthesized at pH = 1 is the most active sample in a broad temperature range.

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Mehmet Ates

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-15

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

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

    Science.gov (United States)

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

    2015-07-01

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

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

    Science.gov (United States)

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

    2017-04-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  10. Comparative photocatalytic study of two selected pesticide derivatives, indole-3-acetic acid and indole-3-butyric acid in aqueous suspensions of titanium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Qamar, M. [Department of Chemistry, Aligarh Muslim University, Aligarh 202002 (India); Muneer, M. [Department of Chemistry, Aligarh Muslim University, Aligarh 202002 (India)]. E-mail: cht12mm@amu.ac.in

    2005-04-11

    Heterogeneous photocatalysed degradation of two selected pesticide derivatives such as indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) has been investigated in aqueous suspensions of titanium dioxide by monitoring the change in substrate concentration employing UV spectroscopic analysis technique and depletion in total organic carbon (TOC) content as a function of irradiation time. The degradation kinetics was studied under different conditions such as pH, types of TiO{sub 2,} substrate and catalyst concentration, and in the presence of electron acceptor such as hydrogen peroxide (H{sub 2}O{sub 2}) besides molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 showed comparatively highest photocatalytics. The pesticide derivative, indole-3-acetic acid was found to degrade slightly faster than indole-3-butyric acid.

  11. Effect of preoperative injection of carbon nanoparticle suspension on the outcomes of selected patients with mid-low rectal cancer.

    Science.gov (United States)

    Zhang, Xing-Mao; Liang, Jian-Wei; Wang, Zheng; Kou, Jian-tao; Zhou, Zhi-Xiang

    2016-04-04

    Carbon nanoparticles show significant lymphatic tropism and can be used to identify lymph nodes surrounding mid-low rectal tumors. In this study, we analyzed the effect of trans anal injection of a carbon nanoparticle suspension on the outcomes of patients with mid-low rectal cancer who underwent laparoscopic resection. We collected the data of 87 patients with mid-low rectal cancer who underwent laparoscopic resection between November 2014 and March 2015 at Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College. For 35 patients in the experimental group, the carbon nanoparticle suspension was injected transanally into the submucosa of the rectum around the tumor 30 min before the operation; 52 patients in the control group underwent the operation directly without the injection of carbon nanoparticle suspension. We then compared the operation outcomes between the two groups. In the experimental group, the rate of incomplete mesorectal excision was lower than that in the control group, but no significant difference was found (2.9% vs. 7.7%, P = 0.342). The distance between the tumor and the circumferential resection margin was 5.8 ± 1.4 mm in the experimental group and 4.8 ± 1.1 mm in the control group (P = 0.001). The mean number of lymph nodes removed was 28.2 ± 9.4 in the experimental group and 22.7 ± 7.3 in the control group (P = 0.003); the mean number of lymph nodes smaller than 5 mm in diameter was 10.1 ± 7.5 and 4.5 ± 3.7, respectively (P rectal cancer; it also improved the accuracy of pathologic staging. Moreover, for selected patients, this technique narrowed the scope of lateral lymph node dissection.

  12. Photocatalytic activity of titanium dioxide modified by Fe2O3 nanoparticles

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  13. Photocatalytic activity of titanium dioxide modified by Fe{sub 2}O{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wodka, Dawid [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland); Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4 (Switzerland); Socha, Robert P.; Bielańska, Elżbieta [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland); Elżbieciak-Wodka, Magdalena [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland); Department of Analytical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4 (Switzerland); Nowak, Paweł, E-mail: ncnowak@cyf-kr.edu.pl [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland); Warszyński, Piotr [J. Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow (Poland)

    2014-11-15

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

  14. Cathodic stripping voltammetric determination of chromium in coastal waters on cubic Nano-titanium carbide loaded gold nanoparticles modified electrode

    Directory of Open Access Journals (Sweden)

    Haitao eHan

    2015-09-01

    Full Text Available The novel cubical nano-titanium carbide loaded gold nanoparticles modified electrode for selective and sensitive detection of trace chromium (Cr in coastal water was established based on a simple approach. Nano-titanium carbide is used as the typical cubical nanomaterial with wonderful catalytic activity towards the reduction of Cr(VI. Gold nanoparticles with excellent physical and chemical properties can facilitate electron transfer and enhance the catalytic activity of the modified electrode. Taking advantage of the synergistic effects of nano-titanium carbide and gold nanoparticles, the excellent cathodic signal responses for the stripping determination of Cr(VI can be obtained. The detection limit of this method is calculated as 2.08 μg L-1 with the linear calibration curve ranged from 5.2 to 1040 μg L-1. This analytical method can be used to detect Cr(VI effectively without using any complexing agent. The fabricated electrode was successfully applied for the detection of chromium in coastal waters collected from the estuary giving Cr concentrations between 12.48 and 22.88 μg L-1 with the recovery between 96% and 105%.

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

    Science.gov (United States)

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

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

  16. Suspensions of polymer-grafted nanoparticles with added polymers-Structure and effective pair-interactions.

    Science.gov (United States)

    Chandran, Sivasurender; Saw, Shibu; Kandar, A K; Dasgupta, C; Sprung, M; Basu, J K

    2015-08-28

    We present the results of combined experimental and theoretical (molecular dynamics simulations and integral equation theory) studies of the structure and effective interactions of suspensions of polymer grafted nanoparticles (PGNPs) in the presence of linear polymers. Due to the absence of systematic experimental and theoretical studies of PGNPs, it is widely believed that the structure and effective interactions in such binary mixtures would be very similar to those of an analogous soft colloidal material-star polymers. In our study, polystyrene-grafted gold nanoparticles with functionality f = 70 were mixed with linear polystyrene (PS) of two different molecular weights for obtaining two PGNP:PS size ratios, ξ = 0.14 and 2.76 (where, ξ = Mg/Mm, Mg and Mm being the molecular weights of grafting and matrix polymers, respectively). The experimental structure factor of PGNPs could be modeled with an effective potential (Model-X), which has been found to be widely applicable for star polymers. Similarly, the structure factor of the blends with ξ = 0.14 could be modeled reasonably well, while the structure of blends with ξ = 2.76 could not be captured, especially for high density of added polymers. A model (Model-Y) for effective interactions between PGNPs in a melt of matrix polymers also failed to provide good agreement with the experimental data for samples with ξ = 2.76 and high density of added polymers. We tentatively attribute this anomaly in modeling the structure factor of blends with ξ = 2.76 to the questionable assumption of Model-X in describing the added polymers as star polymers with functionality 2, which gets manifested in both polymer-polymer and polymer-PGNP interactions especially at higher fractions of added polymers. The failure of Model-Y may be due to the neglect of possible many-body interactions among PGNPs mediated by matrix polymers when the fraction of added polymers is high. These observations point to the need for a new framework to

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

    Science.gov (United States)

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

    2017-11-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2016-12-01

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

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

    NARCIS (Netherlands)

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

    2007-01-01

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

  1. ROS enhancement by silicon nanoparticles in X-ray irradiated aqueous suspensions and in glioma C6 cells

    Energy Technology Data Exchange (ETDEWEB)

    David Gara, Pedro M. [CITOMA, Fundacion Avanzar, Instituto de Terapia Radiante S.A., CIO La Plata (Argentina); Garabano, Natalia I. [University of Buenos Aires, Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, UBA (Argentina); Llansola Portoles, Manuel J. [UNLP, INIFTA, Departamento de Quimica, Facultad de Ciencias Exactas (Argentina); Moreno, M. Sergio [Centro Atomico Bariloche (Argentina); Dodat, Diego; Casas, Oscar R. [CITOMA, Fundacion Avanzar, Instituto de Terapia Radiante S.A., CIO La Plata (Argentina); Gonzalez, Monica C., E-mail: gonzalez@inifta.unlp.edu.ar [UNLP, INIFTA, Departamento de Quimica, Facultad de Ciencias Exactas (Argentina); Kotler, Monica L., E-mail: kotler@qb.fcen.uba.ar [University of Buenos Aires, Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, UBA (Argentina)

    2012-03-15

    The capability of silicon nanoparticles to increase the yield of reactive species upon 4 MeV X-ray irradiation of aqueous suspensions and C6 glioma cell cultures was investigated. ROS generation was detected and quantified using several specific probes. The particles were characterized by FTIR, XPS, TEM, DLS, luminescence, and adsorption spectroscopy before and after irradiation to evaluate the effect of high energy radiation on their structure. The total concentration of O{sub 2}{sup Bullet -}/HO{sub 2}{sup Bullet}, HO{sup Bullet}, and H{sub 2}O{sub 2} generated upon 4-MeV X-ray irradiation of 6.4 {mu}M silicon nanoparticle aqueous suspensions were on the order of 10 {mu}M per Gy, ten times higher than that obtained in similar experiments but in the absence of particles. Cytotoxic {sup 1}O{sub 2} was generated only in irradiation experiments containing the particles. The particle surface became oxidized to SiO{sub 2} and the luminescence yield reduced with the irradiation dose. Changes in the surface morphology did not affect, within the experimental error, the yields of ROS generated per Gy. X-ray irradiation of glioma C6 cell cultures with incorporated silicon nanoparticles showed a marked production of ROS proportional to the radiation dose received. In the absence of nanoparticles, the cells showed no irradiation-enhanced ROS generation. The obtained results indicate that silicon nanoparticles of <5 nm size have the potential to be used as radiosensitizers for improving the outcomes of cancer radiotherapy. Their capability of producing {sup 1}O{sub 2} upon X-ray irradiation opens novel approaches in the design of therapy strategies.

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

    Science.gov (United States)

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

    2013-10-01

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

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

    Science.gov (United States)

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

  4. Smectite clay-inorganic nanoparticle mixed suspensions : Phase behaviour and rheology

    NARCIS (Netherlands)

    Bailey, Louise; Lekkerkerker, Henk N W; Maitland, Geoffrey C.

    2015-01-01

    Smectite clay minerals and their suspensions have long been of both great scientific and applications interest and continue to display a remarkable range of new and interesting behaviour. Recently there has been an increasing interest in the properties of mixed suspensions of such clays with

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

    Science.gov (United States)

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

    2018-07-01

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

  6. Experimental and statistical analysis of surface charge, aggregation and adsorption behaviors of surface-functionalized titanium dioxide nanoparticles in aquatic system

    Energy Technology Data Exchange (ETDEWEB)

    Xiang Chengcheng [West Virginia University, Department of Mechanical and Aerospace Engineering, WVNano Initiative (United States); Yang Feng, E-mail: feng.yang@mail.wvu.edu [West Virginia University, Department of Industrial and Management Systems Engineering (United States); Li Ming [West Virginia University, Department of Mechanical and Aerospace Engineering, WVNano Initiative (United States); Jaridi, Majid [West Virginia University, Department of Industrial and Management Systems Engineering (United States); Wu Nianqiang, E-mail: nick.wu@mail.wvu.edu [West Virginia University, Department of Mechanical and Aerospace Engineering, WVNano Initiative (United States)

    2013-01-15

    One hundred and fifty nanometers sized anatase titanium dioxide nanoparticles (TiO{sub 2} NPs) have been functionalized with the -CH{sub 3}, -NH{sub 2}, -SH, -OH, -COOH, and -SO{sub 3}H terminal groups. Surface charge, aggregation, and adsorption behaviors of the functionalized NPs in aquatic phase have been investigated by a set of experiments following the full factorial design. The dependence of surface charge, suspension size, and surface adsorption upon the various factors (including surface chemistry of NPs, the pH value, and ionic strength of an aqueous solution) has been studied with the statistical methods such as multiple linear regressions and multiple comparison tests. The surface functional group on the TiO{sub 2} NPs affects the characteristics in the simulated aquatic environment. The correlations among the characteristics of NPs have also been investigated by obtaining Pearson's correlation coefficient. The hydrodynamic size is negatively correlated with the absolute value of zeta potential, and positively correlated with the ionic strength. In the NaCl solution, the charge screening effect is responsible for the aggregation. In the CaCl{sub 2} solution, the charge screening effect is dominant mechanism for aggregation at a low salt concentration. In contrast, the interaction between Ca{sup 2+} ions and the specific functional group plays a significant role at a high salt concentration. The adsorption efficiency of humic acid decreases with an increase in the pH value, whereas increases with an increase in the ionic strength. The adsorption efficiency is positively correlated with the zeta potential. The statistical analysis methods and the results have implications in assessment of potential environmental risks posed by engineered nanoparticles.

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

    Directory of Open Access Journals (Sweden)

    Atul Sharma

    2015-09-01

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

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

    Science.gov (United States)

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

    2015-09-22

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

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

    Directory of Open Access Journals (Sweden)

    Bin Song

    2016-04-01

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

  10. Nanoparticles of Titanium and Zinc Oxides as Novel Agents in Tumor Treatment: a Review

    Science.gov (United States)

    Bogdan, Janusz; Pławińska-Czarnak, Joanna; Zarzyńska, Joanna

    2017-03-01

    Cancer has become a global problem. On all continents, a great number of people are diagnosed with this disease. In spite of the progress in medical care, cancer still ends fatal for a great number of the ill, either as a result of a late diagnosis or due to inefficiency of therapies. The majority of the tumors are resistant to drugs. Thus, the search for new, more effective therapy methods continues. Recently, nanotechnology has been attributed with big expectations in respect of the cancer fight. That interdisciplinary field of science creates nanomaterials (NMs) and nanoparticles (NPs) that can be applied, e.g., in nanomedicine. NMs and NPs are perceived as very promising in cancer therapy since they can perform as drug carriers, as well as photo- or sonosensitizers (compounds that generate the formation of reactive oxygen species as a result of either electromagnetic radiation excitation with an adequate wavelength or ultrasound activation, respectively). Consequently, two new treatment modalities, the photodynamic therapy (PDT) and the sonodynamic therapy (SDT) have been created. The attachment of ligands or antibodies to NMs or to NPs improve their selective distribution into the targeted organ or cell; hence, the therapy effectiveness can be improved. An important advantage of the targeted tumor treatment is lowering the cyto- and genotoxicity of active substance towards healthy cells. Therefore, both PDT and SDT constitute a valuable alternative to chemo- or radiotherapy. The vital role in cancer eradication is attributed to two inorganic sensitizers in their nanosized scale: titanium dioxide and zinc oxide.

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

    Science.gov (United States)

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

    2013-10-01

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

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

    Science.gov (United States)

    Zhou, Yingjun; Hong, Fashui; Wang, Ling

    2017-11-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Janine Moll

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

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

    Directory of Open Access Journals (Sweden)

    Verónica Freyre-Fonseca

    2016-01-01

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

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

    Science.gov (United States)

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

    2014-05-01

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

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

    Science.gov (United States)

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

    2016-09-01

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

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

    Science.gov (United States)

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

    2013-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Maria Grazia Ammendolia

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

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

    Science.gov (United States)

    Liu, Kui; Lin, Xialu; Zhao, Jinshun

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hajizadeh Moghaddam A

    2017-03-01

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

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

    Science.gov (United States)

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

    2017-01-04

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

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

    Directory of Open Access Journals (Sweden)

    Ya-Jie Wang

    2014-12-01

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

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Karim Samy El-Said

    2015-01-01

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

  9. Influence of silver and titanium nanoparticles on arbuscular mycorrhizal colonization and accumulation of radiocaesium in Helianthus annuus

    International Nuclear Information System (INIS)

    Dubchak, S.; Ogar, A.; Mietelski, J. W.; Turnau, K.

    2010-01-01

    The influence of arbuscular mycorrhizal fungus on 1 34Cs uptake by Helianthus annuus was studied in a pilot study under growth chamber conditions. Mycorrhizal plants took up five times more 1 34Cs (up to 250,000 Bq kg - 1 dry weight) than non mycorrhizal plants. Silver and titanium nanoparticles, supplied into the surface soil layer decreased both the mycorrhizal colonization and Cs uptake by mycorrhizal plants. The application of activated carbon attenuated the effect of nanoparticles and increased 1 34Cs uptake in the presence of mycorrhizal fungi (up to 400,000 Bq kg - 1 dry weight). The results underline the possible application of phyto remediation techniques based on mycorrhizas assisted plants in decontamination of both radionuclides and nanoparticles. (Author) 27 refs.

  10. Influence of silver and titanium nanoparticles on arbuscular mycorrhizal colonization and accumulation of radiocaesium in Helianthus annuus

    Energy Technology Data Exchange (ETDEWEB)

    Dubchak, S.; Ogar, A.; Mietelski, J. W.; Turnau, K.

    2010-07-01

    The influence of albacore's mycorrhizal fungus on {sup 1}34Cs uptake by Helianthus annuus was studied in a pilot study under growth chamber conditions. Mycorrhizal plants took up five times more {sup 1}34Cs (up to 250,000 Bq kg{sup -}1 dry weight) than non mycorrhizal plants. Silver and titanium nanoparticles, supplied into the surface soil layer decreased both the mycorrhizal colonization and Cs uptake by mycorrhizal plants. The application of activated carbon attenuated the effect of nanoparticles and increased {sup 1}34Cs uptake in the presence of mycorrhizal fungi (up to 400,000 Bq kg{sup -}1 dry weight). The results underline the possible application of phyto remediation techniques based on mycorrhizas assisted plants in decontamination of both radionuclides and nanoparticles. (Author) 27 refs.

  11. Bio-inactivation of human malignant cells through highly responsive diluted colloidal suspension of functionalized magnetic iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Roberta V. [Federal Center of Technological Education of Minas Gerais, Department of Materials (Brazil); Silva-Caldeira, Priscila P. [Federal Center of Technological Education of Minas Gerais, Department of Chemistry (Brazil); Pereira-Maia, Elene C.; Fabris, José D.; Cavalcante, Luis Carlos D. [Federal University of Minas Gerais (UFMG), Department of Chemistry – ICEx (Brazil); Ardisson, José D. [Nuclear Technology Development Center (CDTN) (Brazil); Domingues, Rosana Z., E-mail: rosanazd@yahoo.com.br, E-mail: rosanazd@ufmg.br [Federal University of Minas Gerais (UFMG), Department of Chemistry – ICEx (Brazil)

    2016-04-15

    Magnetic fluids, more specifically aqueous colloidal suspensions containing certain magnetic nanoparticles (MNPs), have recently been gaining special interest due to their potential use in clinical treatments of cancerous formations in mammalians. The technological application arises mainly from their hyperthermic behavior, which means that the nanoparticles dissipate heat upon being exposed to an alternating magnetic field (AMF). If the temperature is raised to slightly above 43 °C, cancer cells are functionally inactivated or killed; however, normal cells tend to survive under those same conditions, entirely maintaining their bioactivity. Recent in vitro studies have revealed that under simultaneous exposure to an AMF and magnetic nanoparticles, certain lines of cancer cells are bio-inactivated even without experiencing a significant temperature increase. This non-thermal effect is cell specific, indicating that MNPs, under alternating magnetic fields, may effectively kill cancer cells under conditions that were previously thought to be implausible, considering that the temperature does not increase more than 5 °C, which is also true in cases for which the concentration of MNPs is too low. To experimentally test for this effect, this study focused on the feasibility of inducing K562 cell death using an AMF and aqueous suspensions containing very low concentrations of MNPs. The assay was designed for a ferrofluid containing magnetite nanoparticles, which were obtained through the co-precipitation method and were functionalized with citric acid; the particles had an average diameter of 10 ± 2 nm and a mean hydrodynamic diameter of approximately 40 nm. Experiments were first performed to test for the ability of the ferrofluid to release heat under an AMF. The results show that for concentrations ranging from 2.5 to 1.0 × 10{sup 3} mg L{sup −1}, the maximum temperature increase was actually less than 2 °C. However, the in vitro test results from K

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  13. Synthesis of aqueous suspensions of magnetic nanoparticles with the co-precipitation of iron ions in the presence of aspartic acid

    Energy Technology Data Exchange (ETDEWEB)

    Pušnik, Klementina; Goršak, Tanja [Department for Materials Synthesis, Jožef Stefan Institute, 1000 Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, 1000 Ljubljana (Slovenia); Drofenik, Miha [Department for Materials Synthesis, Jožef Stefan Institute, 1000 Ljubljana (Slovenia); Faculty of Chemistry and Chemical Engineering, University of Maribor, 2000 Maribor (Slovenia); Makovec, Darko [Department for Materials Synthesis, Jožef Stefan Institute, 1000 Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, 1000 Ljubljana (Slovenia)

    2016-09-01

    There is increasing demand for the production of large quantities of aqueous suspensions of magnetic iron-oxide nanoparticles. Amino acids are one possible type of inexpensive, nontoxic, and biocompatible molecules that can be used as the surfactants for the preparation of stable suspensions. This preparation can be conducted in a simple, one-step process based on the co-precipitation of Fe{sup 3+}/Fe{sup 2+} ions in the presence of the amino acid. However, the presence of this amino acid changes the mechanism of the magnetic nanoparticles' formation. In this investigation we analyzed the influence of aspartic amino acid (Asp) on the formation of magnetic iron-oxide nanoparticles during the co-precipitation. The process of the nanoparticles’ formation was followed using a combination of TEM, x-ray diffractometry, magnetic measurements, in-situ FT-IR spectroscopy, and chemical analysis, and compared with the formation of nanoparticles without the Asp. The Asp forms a coordination complex with the Fe{sup 3+} ions, which impedes the formation of the intermediate iron oxyhydroxide phase and suppresses the growth of the final magnetic iron-oxide nanoparticles. Slower reaction kinetics can lead to the formation of nonmagnetic secondary phases. The aspartic-acid-absorbed nanoparticles can be dispersed to form relatively concentrated aqueous suspensions displaying a good colloidal stability at an increased pH. - Highlights: • Co-precipitation of Fe{sup 3+}/Fe{sup 2+} ions in the presence of aspartic amino acid (Asp). • Through analysis of nanoparticle formation mechanism. • Presence of Asp changes the mechanism of the nanoparticles’ formation. • Asp forms a coordination complex with the Fe{sup 3+} ions. • Asp impedes the formation of iron oxyhydroxide phase and suppresses the growth of iron-oxide nanoparticles. • The aspartic-acid-absorbed nanoparticles form stable aqueous suspensions.

  14. Synthesis of aqueous suspensions of magnetic nanoparticles with the co-precipitation of iron ions in the presence of aspartic acid

    International Nuclear Information System (INIS)

    Pušnik, Klementina; Goršak, Tanja; Drofenik, Miha; Makovec, Darko

    2016-01-01

    There is increasing demand for the production of large quantities of aqueous suspensions of magnetic iron-oxide nanoparticles. Amino acids are one possible type of inexpensive, nontoxic, and biocompatible molecules that can be used as the surfactants for the preparation of stable suspensions. This preparation can be conducted in a simple, one-step process based on the co-precipitation of Fe 3+ /Fe 2+ ions in the presence of the amino acid. However, the presence of this amino acid changes the mechanism of the magnetic nanoparticles' formation. In this investigation we analyzed the influence of aspartic amino acid (Asp) on the formation of magnetic iron-oxide nanoparticles during the co-precipitation. The process of the nanoparticles’ formation was followed using a combination of TEM, x-ray diffractometry, magnetic measurements, in-situ FT-IR spectroscopy, and chemical analysis, and compared with the formation of nanoparticles without the Asp. The Asp forms a coordination complex with the Fe 3+ ions, which impedes the formation of the intermediate iron oxyhydroxide phase and suppresses the growth of the final magnetic iron-oxide nanoparticles. Slower reaction kinetics can lead to the formation of nonmagnetic secondary phases. The aspartic-acid-absorbed nanoparticles can be dispersed to form relatively concentrated aqueous suspensions displaying a good colloidal stability at an increased pH. - Highlights: • Co-precipitation of Fe 3+ /Fe 2+ ions in the presence of aspartic amino acid (Asp). • Through analysis of nanoparticle formation mechanism. • Presence of Asp changes the mechanism of the nanoparticles’ formation. • Asp forms a coordination complex with the Fe 3+ ions. • Asp impedes the formation of iron oxyhydroxide phase and suppresses the growth of iron-oxide nanoparticles. • The aspartic-acid-absorbed nanoparticles form stable aqueous suspensions.

  15. Synthesis of aqueous suspensions of magnetic nanoparticles with the co-precipitation of iron ions in the presence of aspartic acid

    Science.gov (United States)

    Pušnik, Klementina; Goršak, Tanja; Drofenik, Miha; Makovec, Darko

    2016-09-01

    There is increasing demand for the production of large quantities of aqueous suspensions of magnetic iron-oxide nanoparticles. Amino acids are one possible type of inexpensive, nontoxic, and biocompatible molecules that can be used as the surfactants for the preparation of stable suspensions. This preparation can be conducted in a simple, one-step process based on the co-precipitation of Fe3+/Fe2+ ions in the presence of the amino acid. However, the presence of this amino acid changes the mechanism of the magnetic nanoparticles' formation. In this investigation we analyzed the influence of aspartic amino acid (Asp) on the formation of magnetic iron-oxide nanoparticles during the co-precipitation. The process of the nanoparticles' formation was followed using a combination of TEM, x-ray diffractometry, magnetic measurements, in-situ FT-IR spectroscopy, and chemical analysis, and compared with the formation of nanoparticles without the Asp. The Asp forms a coordination complex with the Fe3+ ions, which impedes the formation of the intermediate iron oxyhydroxide phase and suppresses the growth of the final magnetic iron-oxide nanoparticles. Slower reaction kinetics can lead to the formation of nonmagnetic secondary phases. The aspartic-acid-absorbed nanoparticles can be dispersed to form relatively concentrated aqueous suspensions displaying a good colloidal stability at an increased pH.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-30

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

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

    OpenAIRE

    Felemban, Nayef H.; Ebrahim, Mohamed I.

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mojtaba Nakhaei pour

    2017-03-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2017-12-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Smijs TG

    2011-10-01

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

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

    Science.gov (United States)

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

    2014-04-01

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

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

    Science.gov (United States)

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

    2014-09-15

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

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

    Directory of Open Access Journals (Sweden)

    Braun Armin

    2009-09-01

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

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

    Science.gov (United States)

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

    2018-06-04

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

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

    Science.gov (United States)

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

    2015-10-01

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

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

    International Nuclear Information System (INIS)

    Tan, Cheng; Wang, Wen-Xiong

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-15

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Anupam Dhasmana

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-11

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-15

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2015-12-03

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

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

    Science.gov (United States)

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

    2017-09-01

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

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

    Science.gov (United States)

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

    2016-05-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  3. Synthesis, characterization, and photocatalytic activities of Cobalt(II)-Titanium dioxide nanorods, and electrophoretic deposition of Titanium dioxide nanoparticle/nanorod composite films for self-cleaning applications

    Science.gov (United States)

    Kang, Wonjun

    This dissertation consists of two projects. The first project is synthesis, characterization, and photocatalytic activities of Co(II)-TiO2 nanorods. We modified brookite TiO2 nanorods with cobalt(II) ions to design new photocatalysts with visible light absorption. X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) data indicated that the local structure of Co(II)-TiO2 nanorods was shown as tetrahedral and octahedral Co(II) sites at TiO2 nanorod surface. Dimethylglyoxime (DMG) has been used to remove surface Co(II) from Co(II)-TiO2 nanorods to determine single-site Co(II) ions selectively attached to the TiO 2 nanorod surface. We proposed a mechanism that the Co-Co bond of the precursor Co2(CO)8 undergoes heterolysis followed by disproportionation of Co(I) to produce Co(II) and Co(0) precipitate. Finally, the Co(II)-TiO2 nanorods showed greater activity than TiO 2 nanorods in the degradation of 5,8-dihydroxy-1,4-naphthoquinone (DHNQ) dye under visible light irradiation. The second project is electrophoretic deposition (EPD) of TiO2 nanoparticle/nanorod composite films for self-cleaning applications. We developed novel electrolyte system for EPD of TiO2 nanoparticle/nanorod composites for self-cleaning coatings. A mixture of TiO2 powder and TiO2 nanorods was used as EPD suspension in a mixture of THF and acetone. TiO2 nanoparticle/nanorod composite films were fabricated on aluminium substrates via the EPD method, and were characterized by scanning electron microscope (SEM). SEM images showed that TiO2 nanoparticle/nanorod composite films had a uniform pore structure. The hydrophobic properties of surfaces in TiO2 nanoparticle/nanorod composite films were evaluated by water contact angle measurements. It was found that the surfaces of TiO2 nanoparticle/nanorod composite films were hydrophobic with contact angle of 103°. These hydrophobic surfaces are expected to have potential applications for self-cleaning.

  4. Functionalization of γ-alumina cores by polyvinylpirrolidone: properties of the resulting biocompatible nanoparticles in aqueous suspension

    International Nuclear Information System (INIS)

    Fernandez, L.; Arranz, G.; Palacio, L.; Soria, C.; Sanchez, M.; Perez, G.; Lozano, A. E.; Hernandez, A.; Pradanos, P.

    2009-01-01

    A biocompatible polymer has been used to functionalize 45-50 nm diameter γ-alumina nanoparticles. Because the target was to use these systems in real applications, polyvinylpirrolidone (PVP) was chosen due to the characteristics of non-toxicity, biocompatibility, and feasibility of this polymer to form complexes with many cations and chemical species. This approach allows the use of these materials in medicine and food, textile, or pharmaceutical industry. The functionalization process required a previous attachment of an active group on the surface of the nanoparticles. Subsequently, a polymer chain was generated in situ, using vinyltrimethoxysilane (VTMS) and 1-vinyl-2-pyrrolidone (VP) as reactives. The morphology and topology of the nanocompound has been characterized in aqueous suspensions, attending to possible applications in this medium. The results obtained from the different techniques show that the polymer chain was successfully grafted to the nanoparticle surface, and allow an estimation of the size of the modified particle. Their electrical and conformational behavior have also been studied in different aqueous chemical environments.

  5. Functionalization of {gamma}-alumina cores by polyvinylpirrolidone: properties of the resulting biocompatible nanoparticles in aqueous suspension

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, L. [Universidad Nacional del Comahue, Dpto de Quimica, Facultad de Ingenieria (Argentina); Arranz, G.; Palacio, L. [Universidad de Valladolid, Dpto. Fisica Aplicada, Facultad de Ciencias (Spain); Soria, C.; Sanchez, M.; Perez, G. [Universidad Nacional del Comahue, Dpto de Quimica, Facultad de Ingenieria (Argentina); Lozano, A. E. [UA-CSIC-UVA, Surface and Porous Materials (SMAP) (Spain); Hernandez, A.; Pradanos, P., E-mail: pradanos@termo.uva.e [Universidad de Valladolid, Dpto. Fisica Aplicada, Facultad de Ciencias (Spain)

    2009-02-15

    A biocompatible polymer has been used to functionalize 45-50 nm diameter {gamma}-alumina nanoparticles. Because the target was to use these systems in real applications, polyvinylpirrolidone (PVP) was chosen due to the characteristics of non-toxicity, biocompatibility, and feasibility of this polymer to form complexes with many cations and chemical species. This approach allows the use of these materials in medicine and food, textile, or pharmaceutical industry. The functionalization process required a previous attachment of an active group on the surface of the nanoparticles. Subsequently, a polymer chain was generated in situ, using vinyltrimethoxysilane (VTMS) and 1-vinyl-2-pyrrolidone (VP) as reactives. The morphology and topology of the nanocompound has been characterized in aqueous suspensions, attending to possible applications in this medium. The results obtained from the different techniques show that the polymer chain was successfully grafted to the nanoparticle surface, and allow an estimation of the size of the modified particle. Their electrical and conformational behavior have also been studied in different aqueous chemical environments.

  6. New, rapid method to measure dissolved silver concentration in silver nanoparticle suspensions by aggregation combined with centrifugation

    International Nuclear Information System (INIS)

    Dong, Feng; Valsami-Jones, Eugenia; Kreft, Jan-Ulrich

    2016-01-01

    It is unclear whether the antimicrobial activities of silver nanoparticles (AgNPs) are exclusively mediated by the release of silver ions (Ag"+) or, instead, are due to combined nanoparticle and silver ion effects. Therefore, it is essential to quantify dissolved Ag in nanosilver suspensions for investigations of nanoparticle toxicity. We developed a method to measure dissolved Ag in Ag"+/AgNPs mixtures by combining aggregation of AgNPs with centrifugation. We also describe the reproducible synthesis of stable, uncoated AgNPs. Uncoated AgNPs were quickly aggregated by 2 mM Ca"2"+, forming large clusters that could be sedimented in a low-speed centrifuge. At 20,100g, the sedimentation time of AgNPs was markedly reduced to 30 min due to Ca"2"+-mediated aggregation, confirmed by the measurements of Ag content in supernatants with graphite furnace atomic absorption spectrometry. No AgNPs were detected in the supernatant by UV–Vis absorption spectra after centrifuging the aggregates. Our approach provides a convenient and inexpensive way to separate dissolved Ag from AgNPs, avoiding long ultracentrifugation times or Ag"+ adsorption to ultrafiltration membranes.

  7. New, rapid method to measure dissolved silver concentration in silver nanoparticle suspensions by aggregation combined with centrifugation

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Feng, E-mail: fengdongub@gmail.com [University of Birmingham, Institute of Microbiology and Infection, School of Biosciences (United Kingdom); Valsami-Jones, Eugenia [University of Birmingham, School of Geography, Earth and Environmental Sciences (United Kingdom); Kreft, Jan-Ulrich [University of Birmingham, Institute of Microbiology and Infection, School of Biosciences (United Kingdom)

    2016-09-15

    It is unclear whether the antimicrobial activities of silver nanoparticles (AgNPs) are exclusively mediated by the release of silver ions (Ag{sup +}) or, instead, are due to combined nanoparticle and silver ion effects. Therefore, it is essential to quantify dissolved Ag in nanosilver suspensions for investigations of nanoparticle toxicity. We developed a method to measure dissolved Ag in Ag{sup +}/AgNPs mixtures by combining aggregation of AgNPs with centrifugation. We also describe the reproducible synthesis of stable, uncoated AgNPs. Uncoated AgNPs were quickly aggregated by 2 mM Ca{sup 2+}, forming large clusters that could be sedimented in a low-speed centrifuge. At 20,100g, the sedimentation time of AgNPs was markedly reduced to 30 min due to Ca{sup 2+}-mediated aggregation, confirmed by the measurements of Ag content in supernatants with graphite furnace atomic absorption spectrometry. No AgNPs were detected in the supernatant by UV–Vis absorption spectra after centrifuging the aggregates. Our approach provides a convenient and inexpensive way to separate dissolved Ag from AgNPs, avoiding long ultracentrifugation times or Ag{sup +} adsorption to ultrafiltration membranes.

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

    Science.gov (United States)

    Metzler, David M.

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

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

    Science.gov (United States)

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

    2018-04-13

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

  10. Immobilization of Ag nanoparticles/FGF-2 on a modified titanium implant surface and improved human gingival fibroblasts behavior.

    Science.gov (United States)

    Ma, Qianli; Mei, Shenglin; Ji, Kun; Zhang, Yumei; Chu, Paul K

    2011-08-01

    The objective of this study was to form a rapid and firm soft tissue sealing around dental implants that resists bacterial invasion. We present a novel approach to modify Ti surface by immobilizing Ag nanoparticles/FGF-2 compound bioactive factors onto a titania nanotubular surface. The titanium samples were anodized to form vertically organized TiO(2) nanotube arrays and Ag nanoparticles were electrodeposited onto the nanotubular surface, on which FGF-2 was immobilized with repeated lyophilization. A uniform distribution of Ag nanoparticles/FGF-2 was observed on the TiO(2) nanotubular surface. The L929 cell line was used for cytotoxicity assessment. Human gingival fibroblasts (HGFs) were cultured on the modified surface for cytocompatibility determination. The Ag/FGF-2 immobilized samples displayed excellent cytocompatibility, negligible cytotoxicity, and enhanced HGF functions such as cell attachment, proliferation, and ECM-related gene expression. The Ag nanoparticles also exhibit some bioactivity. In conclusion, this modified TiO(2) nanotubular surface has a large potential for use in dental implant abutment. Copyright © 2011 Wiley Periodicals, Inc.

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

    Science.gov (United States)

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

    2018-01-01

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

  12. Self-organized nickel nanoparticles on nanostructured silicon substrate intermediated by a titanium oxynitride (TiNxOy) interface

    Science.gov (United States)

    Morales, M.; Droppa, R., Jr.; de Mello, S. R. S.; Figueroa, C. A.; Zanatta, A. R.; Alvarez, F.

    2018-01-01

    In this work we report an experimental approach by combining in situ sequential top-down and bottom-up processes to induce the organization of nanosized nickel particles. The top-down process consists in xenon ion bombardment of a crystalline silicon substrate to generate a pattern, followed by depositing a ˜15 nm titanium oxynitride thin film to act as a metallic diffusion barrier. Then, metallic nanoparticles are deposited by argon ion sputtering a pure nickel target, and the sample is annealed to promote the organization of the nickel nanoparticles (a bottom-up process). According to the experimental results, the surface pattern and the substrate biaxial surface strain are the driving forces behind the alignment and organization of the nickel nanoparticles. Moreover, the ratio between the F of metallic atoms arriving at the substrate relative to its surface diffusion mobility determines the nucleation regime of the nickel nanoparticles. These features are presented and discussed considering the existing technical literature on the subject.

  13. Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G.; Chathuranga Senarathna, K.G. [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Herath, H.M.T.U. [Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Department of Medical Laboratory Science, Faculty of Allied Health Sciences, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Premachandra, T.N. [Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Ranasinghe, C.S.K. [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Rajapakse, R.P.V.J. [Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Rajapakse, R.M.G., E-mail: rmgr@pdn.ac.lk [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Edirisinghe, Mohan; Mahalingam, S. [Department of Mechanical Engineering, University College London, London WC1E 7JE (United Kingdom); Bandara, I.M.C.C.D. [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD (Australia); Singh, Sanjleena [Central Analytical Research Facility, Institute of Future Environments, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD (Australia)

    2016-06-01

    Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO{sub 2} thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. - Highlights: • Colloidal hydroxyapatite nanorods are prepared by a novel method. • Surfaces of titanium metal plates are modified by self-forming TiO{sub 2} thin-films. • Prostheses are prepared by coating hydroxyapatite on surface modified Ti metal. • Bioactivity and noncytotoxicity are increased with surface modifications.

  14. Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces

    International Nuclear Information System (INIS)

    Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G.; Chathuranga Senarathna, K.G.; Herath, H.M.T.U.; Premachandra, T.N.; Ranasinghe, C.S.K.; Rajapakse, R.P.V.J.; Rajapakse, R.M.G.; Edirisinghe, Mohan; Mahalingam, S.; Bandara, I.M.C.C.D.; Singh, Sanjleena

    2016-01-01

    Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO_2 thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. - Highlights: • Colloidal hydroxyapatite nanorods are prepared by a novel method. • Surfaces of titanium metal plates are modified by self-forming TiO_2 thin-films. • Prostheses are prepared by coating hydroxyapatite on surface modified Ti metal. • Bioactivity and noncytotoxicity are increased with surface modifications.

  15. Photocatalytic degradation of commercial phoxim over La-doped TiO2 nanoparticles in aqueous suspension.

    Science.gov (United States)

    Dai, Ke; Peng, Tianyou; Chen, Hao; Liu, Juan; Zan, Lin

    2009-03-01

    Photocatalytic degradation of commercial phoxim emulsion in aqueous suspension was investigated by using La-doped mesoporous TiO2 nanoparticles (m-TiO2) as the photocatalyst under UV irradiation. Effects of La-doping level, calcination temperature, and additional amount of the photocatalyst on the photocatalytic degradation efficiency were investigated in detail. Experimental results indicate that 20 mg L(-1) phoxim in 0.5 g L(-1) La/m-TiO2 suspension (the initial pH 4.43) can be decomposed as prolonging the irradiation time. Almost 100% phoxim was decomposed after 4 h irradiation according to the spectrophotometric analyses, whereas the mineralization rate of phoxim just reached ca. 80% as checked by ion chromatography (IC) analyses. The elimination of the organic solvent in the phoxim emulsion as well as the formation and decomposition of some degradation intermediates were observed by high-performance liquid chromatography-mass spectroscopy (HPLC-MS). On the basis of the analysis results on the photocatalytic degradation intermediates, two possible photocatalytic degradation pathways are proposed under the present experimental conditions, which reveal that both the hydrolysis and adsorption of phoxim under UV light irradiation play important roles during the photocatalytic degradation of phoxim.

  16. Osseointegration properties of titanium dental implants modified with a nanostructured coating based on ordered porous silica and bioactive glass nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Covarrubias, Cristian, E-mail: ccovarrubias@odontologia.uchile.cl [Laboratory of Nanobiomaterials, Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago (Chile); Mattmann, Matías [Laboratory of Nanobiomaterials, Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago (Chile); Von Marttens, Alfredo [Department of Prosthesis, Faculty of Dentistry, University of Chile, Santiago (Chile); Caviedes, Pablo; Arriagada, Cristián [Laboratory of Cell Therapy, ICBM, Faculty of Medicine, University of Chile (Chile); Valenzuela, Francisco [Laboratory of Nanobiomaterials, Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago (Chile); Rodríguez, Juan Pablo [Laboratory of Cell Biology, INTA, University of Chile, Santiago (Chile); Corral, Camila [Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Santiago (Chile)

    2016-02-15

    Graphical abstract: - Highlights: • The fabrication of a coating for osseointegration of titanium implant is presented. • The coating consists of nanoporous silica loaded with bioactive glass nanoparticles. • Coating accelerates the in vitro formation of apatite in simulated body fluid. • Coating promotes the osteogenic differentiation of stem cells. • Coating accelerates the formation of bone tissue in the periphery of the implant. - Abstract: The fabrication of a nanoporous silica coating loaded with bioactive glass nanoparticles (nBG/NSC) on titanium dental implant surface and its in vitro and in vivo evaluation is presented. The coating was produced by a combined sol–gel and evaporation induced self-assembly process. In vitro bioactivity was assessed in simulated body fluid (SBF) and investigating the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). A rat tibial model was employed to analyze the bone response to nBG/NSC-modified titanium implant surface in vivo. The nBG/NSC coating was confirmed at nano level to be constituted by a highly ordered nanoporous silica structure. The coating nanotopography in conjunction with the bioactivity of the BG particles accelerate the in vitro apatite formation and promote the osteogenic differentiation of hBMSCs in absence of osteogenic supplements. These properties accelerate the formation of bone tissue in the periphery of the implant after 3 weeks of implantation. Backscattered scanning electron microscopy images revealed the presence of gaps and soft tissue in the unmodified implant after 6 weeks, whereas the nBG/NSC-modified implant showed mature bone in intimate contact with the implant surface. The nBG/NSC coating appears promising for accelerating the osseointegration of dental implants.

  17. Osseointegration properties of titanium dental implants modified with a nanostructured coating based on ordered porous silica and bioactive glass nanoparticles

    International Nuclear Information System (INIS)

    Covarrubias, Cristian; Mattmann, Matías; Von Marttens, Alfredo; Caviedes, Pablo; Arriagada, Cristián; Valenzuela, Francisco; Rodríguez, Juan Pablo; Corral, Camila

    2016-01-01

    Graphical abstract: - Highlights: • The fabrication of a coating for osseointegration of titanium implant is presented. • The coating consists of nanoporous silica loaded with bioactive glass nanoparticles. • Coating accelerates the in vitro formation of apatite in simulated body fluid. • Coating promotes the osteogenic differentiation of stem cells. • Coating accelerates the formation of bone tissue in the periphery of the implant. - Abstract: The fabrication of a nanoporous silica coating loaded with bioactive glass nanoparticles (nBG/NSC) on titanium dental implant surface and its in vitro and in vivo evaluation is presented. The coating was produced by a combined sol–gel and evaporation induced self-assembly process. In vitro bioactivity was assessed in simulated body fluid (SBF) and investigating the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). A rat tibial model was employed to analyze the bone response to nBG/NSC-modified titanium implant surface in vivo. The nBG/NSC coating was confirmed at nano level to be constituted by a highly ordered nanoporous silica structure. The coating nanotopography in conjunction with the bioactivity of the BG particles accelerate the in vitro apatite formation and promote the osteogenic differentiation of hBMSCs in absence of osteogenic supplements. These properties accelerate the formation of bone tissue in the periphery of the implant after 3 weeks of implantation. Backscattered scanning electron microscopy images revealed the presence of gaps and soft tissue in the unmodified implant after 6 weeks, whereas the nBG/NSC-modified implant showed mature bone in intimate contact with the implant surface. The nBG/NSC coating appears promising for accelerating the osseointegration of dental implants.

  18. Sun protection enhancement of titanium dioxide crystals by the use of carnauba wax nanoparticles: the synergistic interaction between organic and inorganic sunscreens at nanoscale.

    Science.gov (United States)

    Villalobos-Hernández, J R; Müller-Goymann, C C

    2006-09-28

    Carnauba wax is partially composed of cinnamates. The rational combination of cinnamates and titanium dioxide has shown a synergistic effect to improve the sun protection factor (SPF) of cosmetic preparations. However, the mechanism of this interaction has not been fully understood. In this study, an ethanolic extract of the carnauba wax and an ethanolic solution of a typical cinnamate derivative, ethylcinnamate, were prepared and their UV absorption and SPF either alone or in the presence of titanium dioxide were compared. The titanium dioxide crystals and the cinnamates solutions were also distributed into a matrix composed of saturated fatty acids to emulate the structure of the crystallized carnauba wax. SPF, differential scanning calorimetry (DSC) and X-ray studies of these matrices were performed. Additionally, carnauba wax nanosuspensions containing titanium dioxide either in the lipid phase or in the aqueous phase were prepared to evaluate their SPFs and their physical structure. Strong UV absorption was observed in diluted suspensions of titanium dioxide after the addition of cinnamates. The saturated fatty acid matrices probably favored the adsorption of the cinnamates at the surface of titanium dioxide crystals, which was reflected by an increase in the SPF. No modification of the crystal structure of the fatty acid matrices was observed after the addition of cinnamates or titanium dioxide. The distribution of the titanium dioxide inside the lipid phase of the nanosuspensions was more effective to reach higher SPFs than that at the aqueous phase. The close contact between the carnauba wax and the titanium dioxide crystals after the high-pressure homogenization process was confirmed by transmission electron microscopy (TEM).

  19. Ionic Liquid-Tethered Nanoparticle Suspensions: A Novel Class of Ionogels

    KAUST Repository

    Moganty, Surya S.; Srivastava, Samanvaya; Lu, Yingying; Schaefer, Jennifer L.; Rizvi, Salmaan A.; Archer, Lynden A.

    2012-01-01

    We report a novel class of silica ionogels created by dispersing silica nanoparticles densely grafted with the ionic liquid (IL) 1-trimethoxysilyl propyl-3-methyl-imidazolium bis- (trifluoromethylsulfonyl) imide (SpmImTSFI) in a 1-butyl-3- methyl

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

  4. Comparative study of Eyring and Carreau fluids in a suspension of dust and nickel nanoparticles with variable conductivity

    Science.gov (United States)

    Mamatha Upadhya, S.; Mahesha; Raju, C. S. K.

    2018-04-01

    A theoretical analysis is carried out to investigate the magnetohydrodynamic unsteady flow of Eyring-Powell and Carreau non-Newtonian fluids in a suspension of dust and nickel nanoparticles by considering variable thermal conductivity and thermal radiation. Dispersion of nickel nanoparticles in dusty fluids finds applications in heat exchanger systems, rechargeable batteries, chemical catalysts, metallurgy, conducting paints, magnetic recording media, drug delivery, nanofibers, textiles, etc. The initially arising set of physical governing partial differential equations is transformed to ordinary differential equations (ODEs) with the aid of similarity transformations. Consequentially, the nonlinear ODEs are solved numerically through the Runge-Kutta Fehlberg scheme (RKFS). The computational results for non-dimensional temperature and velocity profiles are presented through graphs. Furthermore, the numerical values of friction factor and heat transfer rate are tabulated numerically for the unsteady and steady cases of the Eyring and Carreau fluid cases and of the dusty non-Newtonian (φ=0) and the dusty non-Newtonian nanofluid (φ≠ 0) cases of the unsteady flow. We also validated the present results with previous published studies and found them to be highly satisfactory. The formulated model reveals that the rate of heat transfer is higher in the mixture of the nickel + Eyring-Powell case compared to the nickel + Carreau case. From this we can highlight that, depending on the industrial appliances, we can use heating or cooling processes for Eyring and Carreau fluids, respectively.

  5. Pyrolytic carbon coating for cytocompatibility of titanium oxide nanoparticles: a promising candidate for medical applications.

    NARCIS (Netherlands)

    Behzadi, S.; Imani, M.; Yousefi, M.; Galinetto, P.; Simchi, A.; Amiri, H.; Stroeve, P.; Mahmoudi, M.

    2012-01-01

    Nanoparticles for biomedical use must be cytocompatible with the biological environment that they are exposed to. Current research has focused on the surface functionalization of nanoparticles by using proteins, polymers, thiols and other organic compounds. Here we show that inorganic nanoparticles

  6. Intensification of the separation of CuO nanoparticles from their highly diluted suspension using a foam flotation column with S type internal

    International Nuclear Information System (INIS)

    Hu, Nan; Li, Rui; Wu, Zhao-liang; Huang, Di; Li, Hong Zhen

    2015-01-01

    Foam flotation is a promising technique for recovering nanoparticles from their highly diluted suspensions. In this work, a novel S type internal was developed to intensify the foam flotation of CuO nanoparticles (357.6 nm in average particle size) from their suspension of 6.2 × 10 −2  mmol/L. By enhancing foam drainage, the S type internal increased the enrichment ratio of CuO nanoparticles by 139.3 ± 12.5 % without significantly affecting their recovery percentage. Under the optimal conditions of Cetyl trimethyl ammonium bromide (CTAB) concentration 0.45 mmol/L, superficial airflow rate 2.6 mm/s, and volumetric feed rate 1.0 mL/min, the enrichment ratio and recovery percentage of CuO nanoparticles reached 81.6 ± 4.1 and 95.4 ± 4.9 %, respectively, using the foam flotation column with the S type internal. Furthermore, about 95 % CTAB could be recycled by recovering CTAB from the foamate and the residual solution. The recovered CuO nanoparticles were associated with CTAB molecules, so they had better dispersity and dispersion stability than the starting CuO nanoparticles. Therefore, they would have good reusability

  7. Optimization of multicomponent aqueous suspensions of lithium iron phosphate (LiFePO4) nanoparticles and carbon black for lithium-ion battery cathodes.

    Science.gov (United States)

    Li, Jianlin; Armstrong, Beth L; Daniel, Claus; Kiggans, Jim; Wood, David L

    2013-09-01

    Addition of polyethyleneimine (PEI) to aqueous LiFePO4 nanoparticle suspensions improves stability and reduces agglomerate size, which is beneficial to lithium-ion battery cathode manufacturing. This research examines the effect of both PEI concentration and molecular weight (MW) on dispersing LiFePO4 and Super P C45 in multicomponent aqueous suspensions. It is demonstrated that the optimal conditions for obtaining stable suspensions with minimal agglomerate size are 1.5 wt% PEI with MW=2000 g mol(-1) and 5.0 wt% PEI with MW=10,000 g mol(-1) for LiFePO4 and Super P C45, respectively. The mixing sequence also affects rheological properties of these suspensions. It is found that dispersing the LiFePO4 and Super P C45 separately yielded suspensions with superior properties (Newtonian rheological behavior, smaller agglomerate size, improved settling, etc.). In particular, dispersing the LiFePO4 prior to the Super P C45 when making the final multicomponent suspension is found to be beneficial, which was evidenced by higher half-cell discharge capacity. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Rezaei Zarchi

    2011-11-01

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

  9. 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.

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

    Science.gov (United States)

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

    2015-08-01

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

  11. Effects of titanium nanoparticles on self-cleaning and structural features of zinc-magnesium-phosphate glass

    International Nuclear Information System (INIS)

    Ismail, S.F.; Sahar, M.R.; Ghoshal, S.K.

    2016-01-01

    Graphical abstract: Water contact angle for sample S2, S3, S4 and S5. The water contact angle increased with increased the titanium NPs content (mol%). - Highlights: • ZnO–MgO–P_2O_5 embedded TiO_2 NPs prepared by conventional melt-quenching method. • The amorphous nature is confirmed by X-ray diffraction spectroscopy. • The structural characteristics of glasses is investigated using FTIR and Raman. • Wettability of the glasses surface by water contact angle. - Abstract: The loss of glass transparency on surface pollutants contamination unless inhibited not only causes vision obscurity but also responsible for major aesthetic damages of cultural heritage. It is due to the sticking of fine dirt particles on wetting layers, a complex process with several possible ramifications still to be clarified. We report the influence of titanium dioxide or titania (TiO_2) nanoparticles (NPs) on the structural and self-cleaning properties of zinc–magnesium–phosphate glasses. Following melt-quenching method glass samples of optimized composition (42 − x)P_2O_5–8MgO–50ZnO–xTiO_2 with x = 0, 1, 2, 3 and 4 mol% are prepared. XRD patterns verified their amorphous nature and TEM images revealed the nucleation of TiO_2 NPs of average diameter ≈4.05 ± 0.01 nm. Fourier transform infrared (FTIR) spectra displayed four absorption band centred at 1618–3438 cm"−"1, 902– 931 cm"−"1, 757–762 cm"−"1 and 531–560 cm"−"1. Raman spectra exhibited four peaks each accompanied by a blue-shift. Water contact angle is found to increase with the increase of titanium NPs concentration into the amorphous matrix. This knowledge can be used to set up strategies and selective treatments to preventing glass transparency loss via the modification of self-cleaning attributes.

  12. Combination of maghemite and titanium oxide nanoparticles in polyvinyl alcohol-alginate encapsulated beads for cadmium ions removal

    Energy Technology Data Exchange (ETDEWEB)

    Majidnia, Zohreh; Idris, Ani [Universiti Teknologi Malaysia, johor bahru (Malaysia)

    2015-06-15

    Both maghemite (γ-Fe{sub 2}O{sub 3}) and titanium oxide (TiO{sub 2}) nanoparticles were mixed at various ratios and embedded in polyvinyl alcohol (PVA)-alginate beads. These beads were tested for photocatalytic behavior in eliminating toxic Cd(Ⅱ) from the aqueous solution. The photocatalytic experiments were performed under sunlight irradiation at various pH, initial feed concentrations and γ-Fe{sub 2}O{sub 3}: TiO{sub 2} ratios. The recycling attribute of these beads was also investigated. The results revealed that 100% of the Cd(Ⅱ) was eliminated in 150 minutes at pH 7 under sunlight. It shows that maghemite and titania PVA-alginate beads can be readily isolated from the aqueous solution after the photocatalyst process and reused for at least six times without losing their initial properties.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-15

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

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

    Science.gov (United States)

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

    2014-07-16

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-04-15

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  18. Osseointegration properties of titanium dental implants modified with a nanostructured coating based on ordered porous silica and bioactive glass nanoparticles

    Science.gov (United States)

    Covarrubias, Cristian; Mattmann, Matías; Von Marttens, Alfredo; Caviedes, Pablo; Arriagada, Cristián; Valenzuela, Francisco; Rodríguez, Juan Pablo; Corral, Camila

    2016-02-01

    The fabrication of a nanoporous silica coating loaded with bioactive glass nanoparticles (nBG/NSC) on titanium dental implant surface and its in vitro and in vivo evaluation is presented. The coating was produced by a combined sol-gel and evaporation induced self-assembly process. In vitro bioactivity was assessed in simulated body fluid (SBF) and investigating the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). A rat tibial model was employed to analyze the bone response to nBG/NSC-modified titanium implant surface in vivo. The nBG/NSC coating was confirmed at nano level to be constituted by a highly ordered nanoporous silica structure. The coating nanotopography in conjunction with the bioactivity of the BG particles accelerate the in vitro apatite formation and promote the osteogenic differentiation of hBMSCs in absence of osteogenic supplements. These properties accelerate the formation of bone tissue in the periphery of the implant after 3 weeks of implantation. Backscattered scanning electron microscopy images revealed the presence of gaps and soft tissue in the unmodified implant after 6 weeks, whereas the nBG/NSC-modified implant showed mature bone in intimate contact with the implant surface. The nBG/NSC coating appears promising for accelerating the osseointegration of dental implants.

  19. Retention of titanium dioxide nanoparticles in biological activated carbon filters for drinking water and the impact on ammonia reduction.

    Science.gov (United States)

    Liu, Zhiyuan; Yu, Shuili; Park, Heedeung; Liu, Guicai; Yuan, Qingbin

    2016-06-01

    Given the increasing discoveries related to the eco-toxicity of titanium dioxide (TiO2) nanoparticles (NPs) in different ecosystems and with respect to public health, it is important to understand their potential effects in drinking water treatment (DWT). The effects of TiO2 NPs on ammonia reduction, ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in biological activated carbon (BAC) filters for drinking water were investigated in static and dynamic states. In the static state, both the nitrification potential and AOB were significantly inhibited by 100 μg L(-1) TiO2 NPs after 12 h (p  0.05). In the dynamic state, different amounts of TiO2 NP pulses were injected into three pilot-scale BAC filters. The decay of TiO2 NPs in the BAC filters was very slow. Both titanium quantification and scanning electron microscope analysis confirmed the retention of TiO2 NPs in the BAC filters after 134 days of operation. Furthermore, the TiO2 NP pulses considerably reduced the performance of ammonia reduction. This study identified the retention of TiO2 NPs in BAC filters and the negative effect on the ammonia reduction, suggesting a potential threat to DWT by TiO2 NPs.

  20. Treatment of a suspension of PCB contaminated soil using iron nanoparticles and electric current

    DEFF Research Database (Denmark)

    Comes, Helena I.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

    2015-01-01

    Contaminated soils and sediments with polychlorinated biphenyls (PCB) are an important environmental problem due to the persistence of these synthetic aromatic compounds and to the lack of a cost-effective and sustainable remediation technology. Recently, a new experimental setup has been proposed...... using electrodialytic remediation and iron nanoparticles. The current work compares the performance of this new setup (A) with conventional electrokinetics (setup B). An historically contaminated soil with an initial PCB concentration of 258 mu g kg-1 was treated during 5, 10, 20 and 45 d using...... different amounts of iron nanoparticles in both setups A and B. A PCB removal of 83% was obtained in setup A compared with 58% of setup B. Setup A also showed additional advantages, such as a higher PCB dechlorination, in a shorter time, with lower nZVI consumption, and with the use of half of the voltage...

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

    Science.gov (United States)

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Haniyeh Moallem Bandani

    2016-10-01

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

  3. The effect of polymer coatings on proton transverse relaxivities of aqueous suspensions of magnetic nanoparticles

    International Nuclear Information System (INIS)

    Carroll, Matthew R J; House, Michael J; Woodward, Robert C; St Pierre, Timothy G; Huffstetler, Phillip P; Miles, William C; Goff, Jonathon D; Davis, Richey M; Riffle, Judy S

    2011-01-01

    Iron oxide magnetic nanoparticles are good candidates for magnetic resonance imaging (MRI) contrast agents due to their high magnetic susceptibilities. Here we investigate 19 polyether-coated magnetite nanoparticle systems comprising three series. All systems were synthesized from the same batch of magnetite nanoparticles. A different polyether was used for each series. Each series comprised systems with systematically varied polyether loadings per particle. A highly significant (p < 0.0001) linear correlation (r = 0.956) was found between the proton relaxivity and the intensity-weighted average diameter measured by dynamic light scattering in the 19 particle systems studied. The intensity-weighted average diameter measured by dynamic light scattering is sensitive to small number fractions of larger particles/aggregates. We conclude that the primary effect leading to differences in proton relaxivity between systems arises from the small degree of aggregation within the samples, which appears to be determined by the nature of the polymer and, for one system, the degree of polymer loading of the particles. For the polyether coatings used in this study, any changes in relaxivity from differences in water exclusion or diffusion rates caused by the polymer are minor in comparison with the changes in relaxivity resulting from variations in the degree of aggregation.

  4. The effect of polymer coatings on proton transverse relaxivities of aqueous suspensions of magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Matthew R J; House, Michael J; Woodward, Robert C; St Pierre, Timothy G [School of Physics, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); Huffstetler, Phillip P; Miles, William C; Goff, Jonathon D; Davis, Richey M; Riffle, Judy S, E-mail: stpierre@physics.uwa.edu.au [Macromolecules and Interfaces Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

    2011-08-12

    Iron oxide magnetic nanoparticles are good candidates for magnetic resonance imaging (MRI) contrast agents due to their high magnetic susceptibilities. Here we investigate 19 polyether-coated magnetite nanoparticle systems comprising three series. All systems were synthesized from the same batch of magnetite nanoparticles. A different polyether was used for each series. Each series comprised systems with systematically varied polyether loadings per particle. A highly significant (p < 0.0001) linear correlation (r = 0.956) was found between the proton relaxivity and the intensity-weighted average diameter measured by dynamic light scattering in the 19 particle systems studied. The intensity-weighted average diameter measured by dynamic light scattering is sensitive to small number fractions of larger particles/aggregates. We conclude that the primary effect leading to differences in proton relaxivity between systems arises from the small degree of aggregation within the samples, which appears to be determined by the nature of the polymer and, for one system, the degree of polymer loading of the particles. For the polyether coatings used in this study, any changes in relaxivity from differences in water exclusion or diffusion rates caused by the polymer are minor in comparison with the changes in relaxivity resulting from variations in the degree of aggregation.

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

    KAUST Repository

    Ismail, Mohamed; Mansour, Morkous S.; Memon, Nasir K.; Anjum, Dalaver H.; Chung, Suk-Ho

    2016-01-01

    A novel double-slit curved wall-jet (DS-CWJ) burner was proposed and utilized for flame synthesis. This burner was comprised of double curved wall-jet nozzles with coaxial slits; the inner slit was for the delivery of titanium tetraisopropoxide

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

    KAUST Repository

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

    2013-01-01

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

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

    Science.gov (United States)

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

  8. Interlaboratory comparison for the measurement of particle size and zeta potential of silica nanoparticles in an aqueous suspension

    Science.gov (United States)

    Lamberty, Andrée; Franks, Katrin; Braun, Adelina; Kestens, Vikram; Roebben, Gert; Linsinger, Thomas P. J.

    2011-12-01

    The Institute for Reference Materials and Measurements has organised an interlaboratory comparison (ILC) to allow the participating laboratories to demonstrate their proficiency in particle size and zeta potential measurements on monomodal aqueous suspensions of silica nanoparticles in the 10-100 nm size range. The main goal of this ILC was to identify competent collaborators for the production of certified nanoparticle reference materials. 38 laboratories from four different continents participated in the ILC with different methods for particle sizing and determination of zeta potential. Most of the laboratories submitted particle size results obtained with centrifugal liquid sedimentation (CLS), dynamic light scattering (DLS) or electron microscopy (EM), or zeta potential values obtained via electrophoretic light scattering (ELS). The results of the laboratories were evaluated using method-specific z scores, calculated on the basis of consensus values from the ILC. For CLS (13 results) and EM (13 results), all reported values were within the ±2 | z| interval. For DLS, 25 of the 27 results reported were within the ±2 | z| interval, the two other results were within the ±3 | z| interval. The standard deviations of the corresponding laboratory mean values varied between 3.7 and 6.5%, which demonstrates satisfactory interlaboratory comparability of CLS, DLS and EM particle size values. From the received test reports, a large discrepancy was observed in terms of the laboratory's quality assurance systems, which are equally important for the selection of collaborators in reference material certification projects. Only a minority of the participating laboratories is aware of all the items that are mandatory in test reports compliant to ISO/IEC 17025 (ISO General requirements for the competence of testing and calibration laboratories. International Organisation for Standardization, Geneva, 2005b). The absence of measurement uncertainty values in the reports, for

  9. Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces.

    Science.gov (United States)

    Wijesinghe, W P S L; Mantilaka, M M M G P G; Chathuranga Senarathna, K G; Herath, H M T U; Premachandra, T N; Ranasinghe, C S K; Rajapakse, R P V J; Rajapakse, R M G; Edirisinghe, Mohan; Mahalingam, S; Bandara, I M C C D; Singh, Sanjleena

    2016-06-01

    Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO2 thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Blood flow of Jeffrey fluid in a catherized tapered artery with the suspension of nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ellahi, R., E-mail: rellahi@engr.ucr.edu [Department of Mechanical Engineering, University of California Riverside (United States); Department of Mathematics and Statistics, FBAS, IIU, Islamabad (Pakistan); Rahman, S.U. [Department of Mathematics and Statistics, FBAS, IIU, Islamabad (Pakistan); Nadeem, S. [Department of Mathematics, Quaid-i-Azam University Islamabad (Pakistan)

    2014-08-14

    Current letter deals with the mathematical models of Jeffrey fluid via nanoparticles in the tapered stenosed atherosclerotic arteries. The convection effects of heat transfer with catheter are also taken into account. The nonlinear coupled equations of nanofluid model are simplified under mild stenosis. The solutions for concentration and temperature are found by using homotopy perturbation method, whereas for velocity profile the exact solution is calculated. Moreover, the expressions for flow impedance and pressure rise are computed and discussed through graphs for different physical quantities of interest. The streamlines have also been presented to discuss the trapping bolus discipline.

  11. Zirconium-titanium-phosphate nanoparticles. Triton X-100 based size modification, characterization and application in radiochemical separation

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, R.; Sen, B.; Chattopadhyay, P. [Burdwan Univ. (India). Dept. of Chemistry

    2014-07-01

    Zirconium-titanium-phosphate nanoparticles (ZTP) of different sizes were synthesized using tritron X-100 (polyethylene glycol-p-isooctylphenyl ether) surfactant. The materials were characterized by FTIR and powdered X-ray diffraction (XRD). The structural and morphological details of the material were obtained by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM study was followed by energy dispersive spectroscopic analysis (EDS) for elemental analysis of the sample. The important peaks of the XRD spectra were analyzed to determine the probable composition of the material. The particle sizes were determined by dynamic light scattering (DLS) method. Ion exchange capacity was measured for different metal ions with sizes of the ZTP nanoparticles and size-dependent ion exchange property of the material was investigated thoroughly. The nanomaterial of the smallest size of around 5 nm was employed to separate carrier-free {sup 137m}Ba from {sup 137}Cs in column chromatographic technique using 1.0 M HNO{sub 3} as eluting agent at pH = 5. (orig.)

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

    Science.gov (United States)

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

    2017-06-01

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

  13. Decomposition of NO in gas phase by gold nanoparticles supported on titanium dioxide synthesized by the deposition-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Fernandez, J., E-mail: javier.fernandez@cimav.edu.mx [Centro de Investigacion en Materiales Avanzados, Av. Miguel de Cervantes 120, Complejo Industrial C.P. 31109, Chihuahua, Chih. (Mexico); Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Eje Central Lazaro Cardenas 152, C.P. 07730, D.F. (Mexico); Zanella, R. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, UNAM, Circuito exterior S/N, Ciudad Universitaria, C.P. 04510, A.P. 70-186, Delegacion Coyoacan, D.F. (Mexico); Aguilar-Elguezabal, A. [Centro de Investigacion en Materiales Avanzados, Av. Miguel de Cervantes 120, Complejo Industrial C.P. 31109, Chihuahua, Chih. (Mexico); Arizabalo, R.D.; Castillo, S.; Moran-Pineda, M. [Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Eje Central Lazaro Cardenas 152, C.P. 07730, D.F. (Mexico)

    2010-10-25

    In the present work, the synthesis, characterization and photoactivity concerning the nitrogen monoxide (NO) decomposition of sol-gel Au/TiO{sub 2} photocatalysts are reported. TiO{sub 2} was prepared by gelling titanium (IV) isopropoxide, and gold nanoparticles were added by the deposition-precipitation method with urea. The catalysts with different gold concentrations were characterized by the following techniques: BET, XRD, UV-vis and dark-field TEM. It was found that by using this synthesis method, a high dispersion of gold nanoparticles on TiO{sub 2} was reached (4.4-6.7 nm), and the obtained structure lead to a band gap energy that is lower than the one observed for undoped TiO{sub 2}. A NO + O{sub 2} mixture (150 ppm) was used to evaluate the photocatalytic activity in situ, at room temperature, under atmospheric pressure and a UV lamp was used as radiation source. The photocatalytic conversion of nitrogen monoxide (NO) was followed by FTIR, which reached 96% in 60 min. The Au/TiO{sub 2} materials showed an enhanced photocatalytic activity when compared with the reference TiO{sub 2}.

  14. Rheological behavior of clay-nanoparticle hybrid-added bentonite suspensions: specific role of hybrid additives on the gelation of clay-based fluids.

    Science.gov (United States)

    Jung, Youngsoo; Son, You-Hwan; Lee, Jung-Kun; Phuoc, Tran X; Soong, Yee; Chyu, Minking K

    2011-09-01

    Two different types of clay nanoparticle hybrid, iron oxide nanoparticle clay hybrid (ICH) and Al(2)O(3)-SiO(2) nanoparticle clay hybrid (ASCH), were synthesized and their effects on the rheological properties of aqueous bentonite fluids in steady state and dynamic state were explored. When ICH particles were added, bentonite particles in the fluid cross-link to form relatively well-oriented porous structure. This is attributed to the development of positively charged edge surfaces in ICH that leads to strengthening of the gel structure of the bentonite susensions. The role of ASCH particles on the interparticle association of the bentonite fluids is different from that of ICH and sensitive to pH. As pH of ASCH-added bentonite suspensions increased, the viscosity, yield stress, storage modulus, and flow stress decreased. In contrast, at low pH, the clay suspensions containing ASCH additives were coagulated and their rheological properties become close to those of ICH added bentonite fluids. A correlation between the net surface charge of the hybrid additives and the rheological properties of the fluids indicates that the embedded nanoparticles within the interlayer space control the variable charge of the edge surfaces of the platelets and determine the particles association behavior of the clay fluids.

  15. Newly Developed Biocompatible Material: Dispersible Titanium-Doped Hydroxyapatite Nanoparticles Suitable for Antibacterial Coating on Intravascular Catheters.

    Science.gov (United States)

    Furuzono, Tsutomu; Okazaki, Masatoshi; Azuma, Yoshinao; Iwasaki, Mitsunobu; Kogai, Yasumichi; Sawa, Yoshiki

    2017-01-01

    Thirteen patients with chlorhexidine-silver sulfadiazine-impregnated catheters have experienced serious anaphylactic shock in Japan. These adverse reactions highlight the lack of commercially available catheters impregnated with strong antibacterial chemical agents. A system should be developed that can control both biocompatibility and antibacterial activity. Hydroxyapatite (HAp) is biocompatible with bone and skin tissues. To provide antibacterial activity by using an external physical stimulus, titanium (Ti) ions were doped into the HAp structure. Highly dispersible, Ti-doped HAp (Ti-HAp) nanoparticles suitable as a coating material were developed. In 3 kinds of Ti-HAp [Ti/(Ca + Ti) = 0.05, 0.1, 0.2], the Ti content in the HAp was approximately 70% of that used in the Ti-HAp preparation, as determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). ICP-AES and X-ray diffraction showed Ti ions were well substituted into the HAp lattice. The nanoparticles were almost uniformly coated on a polyethylene (PE) sheet in a near-monolayer with a surface coverage ratio >95%. The antibacterial activity of the Ti-HAp nanoparticles containing 7.3% Ti ions and coating the sheet was evaluated by calculating the survival ratio of Pseudomonas aeruginosa on the coated sheet after ultraviolet (UV) irradiation. The Ti-HAp-coated sheet showed a 50% decrease in the number of P. aeruginosa compared with that on an uncoated control PE sheet after UV irradiation for 30 s. Key Messages: A system of biocompatibility and antibacterial activity with an on/off switch controlled by external UV stimulation was developed. The system is expected to be applicable in long-term implanted intravascular catheters. © 2017 S. Karger AG, Basel.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2016-03-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  19. Plasmonic Titanium Nitride Nanostructures via Nitridation of Nanopatterned Titanium Dioxide

    DEFF Research Database (Denmark)

    Guler, Urcan; Zemlyanov, Dmitry; Kim, Jongbum

    2017-01-01

    Plasmonic titanium nitride nanostructures are obtained via nitridation of titanium dioxide. Nanoparticles acquired a cubic shape with sharper edges following the rock-salt crystalline structure of TiN. Lattice constant of the resulting TiN nanoparticles matched well with the tabulated data. Energy...

  20. Ultrasound assisted enzymatic hydrolysis for isolating titanium dioxide nanoparticles from bivalve mollusk before sp-ICP-MS.

    Science.gov (United States)

    Taboada-López, María Vanesa; Iglesias-López, Sara; Herbello-Hermelo, Paloma; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2018-08-14

    Applicability of single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) using dwell times equal to or shorter than 100 μs has been tested for assessing titanium dioxide nanoparticles (TiO 2 NPs) in bivalve mollusks. TiO 2 NPs isolation from fresh mollusk tissues was achieved by ultrasound assisted enzymatic hydrolysis procedure using a pancreatin/lipase mixture. Optimum extraction conditions imply ultrasonication (60% amplitude) for 10 min, and 7.5 mL of a solution containing 3.0 g L -1 of pancreatin and lipase (pH 7.4). The developed method was found to be repeatable (repeatability of 17% for the over-all procedure, TiO 2 NPs concentration of 5.33 × 10 7  ± 8.89 × 10 6 , n = 11), showing a limit of detection of 5.28 × 10 6 NPs g -1 , and a limit of detection in size of 24.4-30.4 nm, based on the 3σ criteria, and on the 3σ/5 σ criteria, respectively. The analytical recovery within the 90-99% range (use of TiO 2 NPs standards of 50 nm at 7 and 14 μg L -1 as Ti). Several bivalve mollusks (clams, cockles, mussels, razor clams, oysters and variegated scallops) were analyzed for total titanium (ICP-MS after microwave assisted acid digestion), and for TiO 2 NPs by the proposed method. TiO 2 NPs concentrations were within the 2.36 × 10 7 -1.25 × 10 8 NPs g -1 range, and the most frequent sizes were from 50 to 70 nm. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Preparation of monodispersed Pd nanoparticles by laser ablation at air-suspension interface

    Energy Technology Data Exchange (ETDEWEB)

    Nishi, Teppei, E-mail: e1481@mosk.tytlabs.co.jp; Suzuki, Noritomo; Takahashi, Naoko; Yano, Kazuhisa [Toyota Central R and D Labs., Inc. (Japan)

    2013-04-15

    A novel route to produce nanocolloid of single nano-sized particles was developed. Pd particles are stirred in water. Then laser ablation was conducted using a second harmonic light from Nd:YAG laser system focused on the air-liquid interface. We could obtain yellow nanocolloid. Pd nanoparticles have been stably dispersed in water without any chemical reagents for >1 year. Large absorption below 500 nm could be confirmed. The surface condition of colloidal particles was analyzed by X-ray photoelectron spectroscopy (XPS) of dried particles on Si wafer and pH measurement of nanocolloid. The range of pH value of nanocolloid was from 2 to 3. On the other hand, NO{sub 3} and NO{sub 2} were detected on the dried sample by XPS spectrum. In addition, transmission electron microscopy and dynamic light scattering (DLS) methods revealed a very narrow size distribution. The size distribution in the range from 0.5 to 1.5 nm was confirmed by DLS method. The size distribution and stability of Pd nanocolloid could be explained by chemical reaction between air, water, and Pd target due to excitation by pulsed laser irradiation and production of active particles in the laser-induced plasma.

  2. Preparation of monodispersed Pd nanoparticles by laser ablation at air–suspension interface

    International Nuclear Information System (INIS)

    Nishi, Teppei; Suzuki, Noritomo; Takahashi, Naoko; Yano, Kazuhisa

    2013-01-01

    A novel route to produce nanocolloid of single nano-sized particles was developed. Pd particles are stirred in water. Then laser ablation was conducted using a second harmonic light from Nd:YAG laser system focused on the air–liquid interface. We could obtain yellow nanocolloid. Pd nanoparticles have been stably dispersed in water without any chemical reagents for >1 year. Large absorption below 500 nm could be confirmed. The surface condition of colloidal particles was analyzed by X-ray photoelectron spectroscopy (XPS) of dried particles on Si wafer and pH measurement of nanocolloid. The range of pH value of nanocolloid was from 2 to 3. On the other hand, NO 3 and NO 2 were detected on the dried sample by XPS spectrum. In addition, transmission electron microscopy and dynamic light scattering (DLS) methods revealed a very narrow size distribution. The size distribution in the range from 0.5 to 1.5 nm was confirmed by DLS method. The size distribution and stability of Pd nanocolloid could be explained by chemical reaction between air, water, and Pd target due to excitation by pulsed laser irradiation and production of active particles in the laser-induced plasma.

  3. Titanium Nitride Nanoparticle Electrocatalysts for Oxygen Reduction Reaction in Alkaline Solution

    KAUST Repository

    Ohnishi, R.; Katayama, M.; Cha, Dong Kyu; Takanabe, Kazuhiro; Kubota, J.; Domen, K.

    2013-01-01

    Monodispersed TiN nanoparticles with a narrow size distribution (7–23 nm) were synthesized using mesoporous graphitic (mpg)-C3N4 templates with different pore sizes. The nano-materials were examined as electrocatalysts for oxygen reduction reaction (ORR) in alkaline media. The TiN nanoparticles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2 sorption, transmission electron microscopy (TEM), and C-H-N elemental analysis. The ORR current increased as the TiN particle size decreased, and hence the surface area of TiN nanoparticles reactive to ORR increased. Rotating ring disk electrode (RRDE) measurements revealed that the ORR on TiN surfaces proceeded mainly via a two-electron pathway, producing H2O2 as the main product. Mechanistic aspects of ORR on TiN surfaces are discussed.

  4. Titanium Nitride Nanoparticle Electrocatalysts for Oxygen Reduction Reaction in Alkaline Solution

    KAUST Repository

    Ohnishi, R.

    2013-03-12

    Monodispersed TiN nanoparticles with a narrow size distribution (7–23 nm) were synthesized using mesoporous graphitic (mpg)-C3N4 templates with different pore sizes. The nano-materials were examined as electrocatalysts for oxygen reduction reaction (ORR) in alkaline media. The TiN nanoparticles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2 sorption, transmission electron microscopy (TEM), and C-H-N elemental analysis. The ORR current increased as the TiN particle size decreased, and hence the surface area of TiN nanoparticles reactive to ORR increased. Rotating ring disk electrode (RRDE) measurements revealed that the ORR on TiN surfaces proceeded mainly via a two-electron pathway, producing H2O2 as the main product. Mechanistic aspects of ORR on TiN surfaces are discussed.

  5. Hyperbranched polyglycerol-grafted titanium oxide nanoparticles: synthesis, derivatization, characterization, size separation, and toxicology

    Science.gov (United States)

    Qin, Hongmei; Maruyama, Kyouhei; Amano, Tsukuru; Murakami, Takashi; Komatsu, Naoki

    2016-10-01

    We have been developing surface functionalization of various nanoparticles including nanodiamond and iron oxide nanoparticles in view of biomedical applications. In this context, TiO2 nanoparticles (TiO2 NP) are functionalized with polyglycerol (PG) to provide water-dispersible TiO2-PG, which is further derivatized through multi-step organic transformations. The resulting TiO2-PG and its derivatives are fully characterized by various analyses including solution-phase 1H and 13C NMR. TiO2-PG was size-tuned with centrifugation by changing the acceleration and duration. At last, no cytotoxicity of TiO2 NP, TiO2-PG, and TiO2-PG functionalized with RGD peptide was observed under dark conditions.

  6. Effect of AOT Microemulsion Composition on the Hydrodynamic Diameter and Electrophoretic Mobility of Titanium Oxide Nanoparticles

    Science.gov (United States)

    Shaparenko, N. O.; Beketova, D. I.; Demidova, M. G.; Bulavchenko, A. I.

    2018-05-01

    The hydrodynamic diameter and electrophoretic mobility of titania nanoparticles in AOT microemulsions are studied depending on their water content (from 0 to 1.5 vol %), chloroform content in n-decane-chloroform mixture (from 0 to 30 vol %) and temperature (from 0 to 60°C). Considerable changes in diameter (from 20 to 400 nm) are detected upon adding water to the microemulsion. The electrophoretic mobility grows by 2-3 times upon adding chloroform, or as the temperature falls. The observed features allow us to halve the time of electrophoretic concentration for 140 nm TiO2 nanoparticles, and to concentrate 14 nm nanoparticles that do not exhibit electrophoretic mobility in the absence of chloroform.

  7. Effects of titanium nanoparticles on self-cleaning and structural features of zinc-magnesium-phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, S.F.; Sahar, M.R., E-mail: mrahim057@gmail.com; Ghoshal, S.K.

    2016-02-15

    Graphical abstract: Water contact angle for sample S2, S3, S4 and S5. The water contact angle increased with increased the titanium NPs content (mol%). - Highlights: • ZnO–MgO–P{sub 2}O{sub 5} embedded TiO{sub 2} NPs prepared by conventional melt-quenching method. • The amorphous nature is confirmed by X-ray diffraction spectroscopy. • The structural characteristics of glasses is investigated using FTIR and Raman. • Wettability of the glasses surface by water contact angle. - Abstract: The loss of glass transparency on surface pollutants contamination unless inhibited not only causes vision obscurity but also responsible for major aesthetic damages of cultural heritage. It is due to the sticking of fine dirt particles on wetting layers, a complex process with several possible ramifications still to be clarified. We report the influence of titanium dioxide or titania (TiO{sub 2}) nanoparticles (NPs) on the structural and self-cleaning properties of zinc–magnesium–phosphate glasses. Following melt-quenching method glass samples of optimized composition (42 − x)P{sub 2}O{sub 5}–8MgO–50ZnO–xTiO{sub 2} with x = 0, 1, 2, 3 and 4 mol% are prepared. XRD patterns verified their amorphous nature and TEM images revealed the nucleation of TiO{sub 2} NPs of average diameter ≈4.05 ± 0.01 nm. Fourier transform infrared (FTIR) spectra displayed four absorption band centred at 1618–3438 cm{sup −1}, 902– 931 cm{sup −1}, 757–762 cm{sup −1} and 531–560 cm{sup −1}. Raman spectra exhibited four peaks each accompanied by a blue-shift. Water contact angle is found to increase with the increase of titanium NPs concentration into the amorphous matrix. This knowledge can be used to set up strategies and selective treatments to preventing glass transparency loss via the modification of self-cleaning attributes.

  8. Size and shape dependent Gibbs free energy and phase stability of titanium and zirconium nanoparticles

    International Nuclear Information System (INIS)

    Xiong Shiyun; Qi Weihong; Huang Baiyun; Wang Mingpu; Li Yejun

    2010-01-01

    The Debye model of Helmholtz free energy for bulk material is generalized to Gibbs free energy (GFE) model for nanomaterial, while a shape factor is introduced to characterize the shape effect on GFE. The structural transitions of Ti and Zr nanoparticles are predicted based on GFE. It is further found that GFE decreases with the shape factor and increases with decreasing of the particle size. The critical size of structural transformation for nanoparticles goes up as temperature increases in the absence of change in shape factor. For specified temperature, the critical size climbs up with the increase of shape factor. The present predictions agree well with experiment values.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-10-30

    Mammalian and in vitro studies have raised concerns about the toxicity of titanium dioxide nanoparticles (TiO{sub 2} NPs), but there are very limited data on ecotoxicity to aquatic life. This paper is an observational study where we aim to describe the toxicity of TiO{sub 2} NPs to the main body systems of rainbow trout. Stock solutions of dispersed TiO{sub 2} NPs were prepared by sonication without using solvents. A semi-static test system was used to expose rainbow trout to either a freshwater control, 0.1, 0.5, or 1.0 mg l{sup -1} TiO{sub 2} NPs for up to 14 days. Exposure to TiO{sub 2} NPs caused some gill pathologies including oedema and thickening of the lamellae. No major haematological or blood disturbances were observed in terms of red and white blood cell counts, haematocrit values, whole blood haemoglobin, and plasma Na{sup +} or K{sup +} concentrations. Tissue metal levels (Na{sup +}, K{sup +}, Ca{sup 2+} and Mn) were generally unaffected. However, some exposure concentration-dependent changes in tissue Cu and Zn levels were observed, especially in the brain. Exposure to TiO{sub 2} NPs caused statistically significant decreases in Na{sup +}K{sup +}-ATPase activity (ANOVA, P < 0.05) in the gills and intestine, and a trend of decreasing enzyme activity in the brain (the latter was not statistically significant). Thiobarbituric acid reactive substances (TBARS) showed exposure concentration-dependent and statistically significant (ANOVA or Kruskal-Wallis test, P < 0.05) increases (two-fold or more) in the gill, intestine and brain, but not the liver during exposure to TiO{sub 2} NPs compared to controls. TiO{sub 2} NP exposure caused statistically significant (ANOVA, P < 0.05) increases in the total glutathione levels in the gills, but depletion of hepatic glutathione compared to controls. Total glutathione levels in the brain and intestine were unaffected. Liver cells exposed to TiO{sub 2} NPs showed minor fatty change and lipidosis, and some hepatocytes

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-15

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

  11. MMB4 DMS nanoparticle suspension formulation with enhanced stability for the treatment of nerve agent intoxication.

    Science.gov (United States)

    Dixon, Hong; Clark, Andrew P-Z; Cabell, Larry A; McDonough, Joe A

    2013-01-01

    Various oximes are currently fielded or under investigation in the United States and other countries as a component of autoinjector emergency treatment systems for organophosphate nerve agent chemical weapons. Bis-pyridinium oximes in general have greater efficacy against a broad spectrum of nerve agents, but they have poor stability due to hydrolytic degradation at elevated temperatures. 1,1'-Methylenebis-4-[(hydroxyimino)methyl]pyridinium dimethanesulfonate (MMB4 DMS) is a leading candidate for next-generation nerve agent treatment systems, because it is more stable than other bis-pyridinium oximes, but it still degrades quickly at temperatures often encountered during storage and field use. The primary goal is to increase the stability and shelf life of MMB4 while maintaining the desirable pharmacokinetic (PK) properties of the aqueous formulation. We have developed a formulation to be used in a phase 1 clinical trial consisting of MMB4 micro/nanoparticles suspended in cottonseed oil, a biocompatible vegetable oil. Through various milling techniques, the average particle size can be controlled from approximately 200 to 6000 nm to produce non-Newtonian formulations that are viscous enough to resist rapid particle sedimentation while remaining injectable at a range of concentrations from 5 to 400 mg/mL. The preliminary accelerated stability test shows that MMB4 in these formulations is stable for at least 2 years at temperatures up to 80°C. Preliminary preclinical in vivo studies have demonstrated that all concentrations and particle sizes have desirable PK properties, including high bioavailability and rapid absorption, which is critical to combat potent and fast-acting nerve agents.

  12. Application of titanium oxide nanotube films containing gold nanoparticles for the electroanalytical determination of ascorbic acid

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, Mir Ghasem, E-mail: mg-hosseini@tabrizu.ac.ir; Faraji, Masoud; Momeni, Mohamad Mohsen

    2011-03-31

    Au/TiO{sub 2}/Ti electrodes have been prepared by galvanic deposition of gold particles on TiO{sub 2} nanotube substrates. Titanium oxide nanotubes are fabricated by anodizing titanium foil in a Dimethyl Sulfoxide electrolyte containing fluoride. The scanning electron microscopy results indicated that gold particles are homogeneously deposited on the surface of TiO{sub 2} nanotubes. The TiO{sub 2} layers consist of individual tubes of about 40-80 nm diameters. The electro-catalytic behavior of Au/TiO{sub 2}/Ti and flat gold electrodes for the ascorbic acid electro-oxidation was studied by cyclic voltammetry. The results showed that the flat gold electrode is not suitable for the oxidation of ascorbic acid. However, the Au/TiO{sub 2}/Ti electrodes are shown to possess catalytic activity toward the oxidation reaction. Catalytic oxidation peak current showed a linear dependence on the ascorbic acid concentration and a linear calibration curve is obtained in the concentration range of 1-5 mM of ascorbic acid. Also, determination of ascorbic acid in real samples was evaluated. The obtained results were found to be satisfactory. Finally the effects of interference on the detection of ascorbic acid were investigated.

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

    Science.gov (United States)

    Lee, Woo-Mi; An, Youn-Joo

    2013-04-01

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

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

    KAUST Repository

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

    2013-01-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-30

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

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

    Directory of Open Access Journals (Sweden)

    Gehr Peter

    2007-08-01

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

  3. Effects of Cerium and Titanium Oxide Nanoparticles in Soil on the Nutrient Composition of Barley (Hordeum vulgare L. Kernels

    Directory of Open Access Journals (Sweden)

    Filip Pošćić

    2016-06-01

    Full Text Available The implications of metal nanoparticles (MeNPs are still unknown for many food crops. The purpose of this study was to evaluate the effects of cerium oxide (nCeO2 and titanium oxide (nTiO2 nanoparticles in soil at 0, 500 and 1000 mg·kg−1 on the nutritional parameters of barley (Hordeum vulgare L. kernels. Mineral nutrients, amylose, β-glucans, amino acid and crude protein (CP concentrations were measured in kernels. Whole flour samples were analyzed by ICP-AES/MS, HPLC and Elemental CHNS Analyzer. Results showed that Ce and Ti accumulation under MeNPs treatments did not differ from the control treatment. However, nCeO2 and nTiO2 had an impact on composition and nutritional quality of barley kernels in contrasting ways. Both MeNPs left β-glucans unaffected but reduced amylose content by approximately 21%. Most amino acids and CP increased. Among amino acids, lysine followed by proline saw the largest increase (51% and 37%, respectively. Potassium and S were both negatively impacted by MeNPs, while B was only affected by 500 mg nCeO2·kg−1. On the contrary Zn and Mn concentrations were improved by 500 mg nTiO2·kg−1, and Ca by both nTiO2 treatments. Generally, our findings demonstrated that kernels are negatively affected by nCeO2 while nTiO2 can potentially have beneficial effects. However, both MeNPs have the potential to negatively impact malt and feed production.

  4. Titanium dioxide nanoparticles stimulate sea urchin immune cell phagocytic activity involving TLR/p38 MAPK-mediated signalling pathway

    Science.gov (United States)

    Pinsino, Annalisa; Russo, Roberta; Bonaventura, Rosa; Brunelli, Andrea; Marcomini, Antonio; Matranga, Valeria

    2015-01-01

    Titanium dioxide nanoparticles (TiO2NPs) are one of the most widespread-engineered particles in use for drug delivery, cosmetics, and electronics. However, TiO2NP safety is still an open issue, even for ethical reasons. In this work, we investigated the sea urchin Paracentrotus lividus immune cell model as a proxy to humans, to elucidate a potential pathway that can be involved in the persistent TiO2NP-immune cell interaction in vivo. Morphology, phagocytic ability, changes in activation/inactivation of a few mitogen-activated protein kinases (p38 MAPK, ERK), variations of other key proteins triggering immune response (Toll-like receptor 4-like, Heat shock protein 70, Interleukin-6) and modifications in the expression of related immune response genes were investigated. Our findings indicate that TiO2NPs influence the signal transduction downstream targets of p38 MAPK without eliciting an inflammatory response or other harmful effects on biological functions. We strongly recommend sea urchin immune cells as a new powerful model for nano-safety/nano-toxicity investigations without the ethical normative issue. PMID:26412401

  5. Role of toll-like receptors 3, 4 and 7 in cellular uptake and response to titanium dioxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Peng Chen, Koki Kanehira and Akiyoshi Taniguchi

    2013-01-01

    Full Text Available Innate immune response is believed to be among the earliest provisional cellular responses, and mediates the interactions between microbes and cells. Toll-like receptors (TLRs are critical to these interactions. We hypothesize that TLRs also play an important role in interactions between nanoparticles (NPs and cells, although little information has been reported concerning such an interaction. In this study, we investigated the role of TLR3, TLR4 and TLR7 in cellular uptake of titanium dioxide NP (TiO2 NP agglomerates and the resulting inflammatory responses to these NPs. Our data indicate that TLR4 is involved in the uptake of TiO2 NPs and promotes the associated inflammatory responses. The data also suggest that TLR3, which has a subcellular location distinct from that of TLR4, inhibits the denaturation of cellular protein caused by TiO2 NPs. In contrast, the unique cellular localization of TLR7 has middle-ground functional roles in cellular response after TiO2 NP exposure. These findings are important for understanding the molecular interaction mechanisms between NPs and cells.

  6. Influence of Titanium Dioxide Nanoparticles on the Sulfate Attack upon Ordinary Portland Cement and Slag-Blended Mortars

    Directory of Open Access Journals (Sweden)

    Atta-ur-Rehman

    2018-02-01

    Full Text Available In this study, the effects of titanium dioxide (TiO2 nanoparticles on the sulfate attack resistance of ordinary Portland cement (OPC and slag-blended mortars were investigated. OPC and slag-blended mortars (OPC:Slag = 50:50 were made with water to binder ratio of 0.4 and a binder to sand ratio of 1:3. TiO2 was added as an admixture as 0%, 3%, 6%, 9% and 12% of the binder weight. Mortar specimens were exposed to an accelerated sulfate attack environment. Expansion, changes in mass and surface microhardness were measured. Scanning Electron Microscopy (SEM, Energy Dispersive Spectroscopy (EDS, X-ray Diffraction (XRD, Thermogravimetry Analysis (TGA and Differential Scanning Calorimetry (DSC tests were conducted. The formation of ettringite and gypsum crystals after the sulfate attack were detected. Both these products had caused crystallization pressure in the microstructure of mortars and deteriorated the mortars. Our results show that the addition of nano-TiO2 accelerated expansion, variation in mass, loss of surface microhardness and widened cracks in OPC and slag-blended mortars. Nano-TiO2 containing slag-blended mortars were more resistant to sulfate attack than nano-TiO2 containing OPC mortars. Because nano-TiO2 reduced the size of coarse pores, so it increased crystallization pressure due to the formation of ettringite and gypsum thus led to more damage under sulfate attack.

  7. Plasticized Starch Based Bionanocomposites Containing Cellulose Nanowhiskers and Titanium Dioxide Nanoparticles: Study of Structure and Water Vapor Permeability

    Directory of Open Access Journals (Sweden)

    Nasrin Jamshidi Kaljahi

    2014-08-01

    Full Text Available The starch-based films have some disadvantages such as weak mechanical and poor water barrier properties that restrict their applications in food packaging. In the present research, to improve the properties of the starch films, a constant level of citric acid and polyvinyl alcohol (PVA (10% with different amounts of glycerol (GLY as a lubricating agent, crystal nanowhiskers (CNW and titanium dioxide (TiO2 nanoparticles were used together. Finally, the effects of these compounds on permeability properties of the obtained starch-based bionanocomposites were studied and their optimum values were determined by central composite design of response surface methodology (RSM. The results of X-Ray diffraction (XRD test showed that at low levels of TiO2 and CNW there was no diffractogram peak obtained. However, at high levels of TiO2 and CNW there emerged distinct and sharp peak which was attributed to greater crystalline region and probably non-homogeneity in particle distribution. The Fourier transmission infrared (FTIR data showed that addition of CNW and TiO2 increased hydrogen binding between the nanofillers and biopolymer matrix. The effects of TiO2 and CNW concentrations as quadratic and glycerol concentration as linear and quadratic were significant on water vapor permeability (WVP. The optimum levels of TiO2, CNW and GLY for obtaining minimum WVP corresponded to 0.118, 0.3 g and 1.06 mL, respectively.

  8. Lactate biosensor based on a bionanocomposite composed of titanium oxide nanoparticles, photocatalytically reduced graphene, and lactate oxidase

    International Nuclear Information System (INIS)

    Casero, Elena; Petit- Domínguez, María Dolores; Parra-Alfambra, Ana María; Suárez, Edna; Pariente, Félix; Lorenzo, Encarnación; Alonso, Concepción; Vázquez, Luis; Álvarez-García, Susana; Andrés, Alicia de; Merino, Pablo

    2014-01-01

    We have developed a lactate biosensor based on a bionanocomposite (BNC) composed of titanium dioxide nanoparticles (TiO 2 -NPs), photo catalytically reduced graphene, and lactate oxidase. Graphene oxide was photochemically reduced (without using any chemical reagents) in the presence of TiO 2 -NPs to give graphene nano sheets that were characterized by atomic force microscopy, Raman and X-ray photoelectron spectroscopy. The results show the nano sheets to possess few oxygen functionalities only and to be decorated with TiO 2 -NPs. These nano sheets typically are at least 1 μm long and have a thickness of 4.2 nm. A BNC was obtained by mixing lactate oxidase with the nano sheets and immobilized on the surface of a glassy carbon electrode. The resulting biosensor was applied to the determination of lactate. Compared to a sensor without TiO 2 -NPs, the sensor exhibits higher sensitivity (6.0 μA mM −1 ), a better detection limit (0.6 μM), a wider linear response (2.0 μM to 0.40 mM), and better reproducibility (3.2 %). (author)

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

    Science.gov (United States)

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

    2017-07-11

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

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

    Directory of Open Access Journals (Sweden)

    Akiyoshi Taniguchi

    2013-06-01

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

  11. Efficiency of a Photoreactor Packed with Immobilized Titanium Dioxide Nanoparticles in the Removal of Acid Orange 7.

    Science.gov (United States)

    Sheidaei, Behnaz; Behnajady, Mohammad A

    2016-05-01

    In this paper, the removal efficiency of Color Index Acid Orange 7 (AO7) as a model contaminant was investigated in a batch-recirculated photoreactor packed with immobilized titanium dioxide type P25 nanoparticles on glass beads. The effects of different operational parameters such as the initial concentration of AO7, the volume of solution, the volumetric flowrate, and the light source power in the photoreactor were investigated. The results indicate that the removal percent increased with the rise in volumetric flowrate and power of the light source, but decreased with the rise of the initial concentration of AO7 and the volume of solution. The AO7 degradation was followed through total organic carbon, gas chromatography/mass spectroscopy (GC/MS), and mineralization products analysis. The ammonium and sulfate ions were analyzed as mineralization products of nitrogen and sulfur heteroatoms, respectively. The results of GC/MS revealed the production of 1-indanone, 1-phthalanone, and 2-naphthalenol as intermediate products for the removal of AO7 in this process.

  12. Luminescent Study of the Binding Interaction on 1,4-Dihydroxy-2,3-Dimethyl-9,10-Anthraquinone with Titanium Dioxide Nanoparticles

    Science.gov (United States)

    Pushpam, S.; Yamini, D.; Ramakrishnan, V.

    2014-07-01

    The photophysical properties of 1,4-dihydroxy-2,3-dimethyl-9,10-anthroquinone (DHDMAQ) in the absence and presence of titanium dioxide (TiO2) nanoparticles have been studied using UV-visible absorption spectroscopy and steady-state fluorescence spectroscopy. The fluorescence intensity of the DHDMAQ decreases as the concentration of TiO2 nanoparticles increases. The quenching is characterized by a Stern-Volmer plot, which displays a positive deviation from linearity. This could be explained by static quenching models. The Stern-Volmer quenching constant, association constant, and binding constant have been calculated. The distance between DHDMAQ and TiO2 nanoparticles has also been evaluated using Forster's theory of non-radiative energy transfer.

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

    Science.gov (United States)

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

    2017-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Thu Hong Anh Ngo

    2016-12-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-15

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

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

    International Nuclear Information System (INIS)

    Nakamura, Liana Key Okada

    2012-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  19. Evaluating the use of zinc oxide and titanium dioxide nanoparticles in a metalworking fluid from a toxicological perspective

    Energy Technology Data Exchange (ETDEWEB)

    Seyedmahmoudi, S. H. [Oregon State University, Industrial Sustainability Laboratory, School of Mechanical, Industrial, and Manufacturing Engineering (United States); Harper, Stacey L. [Oregon State University, Department of Environmental and Molecular Toxicology & School of Chemical, Biological and Environmental Engineering (United States); Weismiller, Michael C. [Master Chemical Corporation (United States); Haapala, Karl R., E-mail: karl.haapala@oregonstate.edu [Oregon State University, Industrial Sustainability Laboratory, School of Mechanical, Industrial, and Manufacturing Engineering (United States)

    2015-02-15

    Adding nanoparticles (NPs) to metalworking fluids (MWFs) has been shown to improve performance in metal cutting. Zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO{sub 2} NPs), for example, have exhibited the ability to improve lubricant performance, decrease the heat created by machining operations, reduce friction and wear, and enhance thermal conductivity. ZnO and TiO{sub 2} NPs are also relatively inexpensive compared to many other NPs. Precautionary concerns of human health risks and environmental impacts, however, are especially important when adding NPs to MWFs. The goal of this research is to investigate the potential environmental and human health effects of these nanoenabled products during early design and development. This research builds on a prior investigation of the stability and toxicity characteristics of NPs used in metalworking nanofluids (MWnF™). The previous study only investigated one type of NP at one level of concentration. This research expands on the previous investigations through the valuation of three different types of NPs that vary in morphology (size and shape) and was conducted over a wide range of concentrations in the base fluid. In the presented work, mixtures of a microemulsion (TRIM{sup ®} MicroSol{sup ®} 585XT), two different types of TiO{sub 2} NPs (referred to as TiO{sub 2}A and TiO{sub 2}B) and one type of ZnO NP were used to evaluate MWnF™ stability and toxicity. Dynamic light scattering was used to assess stability over time and an embryonic zebrafish assay was used to assess toxicological impacts. The results reveal that, in general, the addition of these NPs increased toxicity relative to the NP-free formulation. The lowest rate of zebrafish malformations occurred at 5 g/L TiO{sub 2}A NP, which was even lower than for the base fluid. This result is particularly promising for future MWnF™ development, given that the mortality rate for 5 g/L TiO{sub 2}A was not significantly different

  20. Interaction of fibrinogen and albumin with titanium dioxide nanoparticles of different crystalline phases

    International Nuclear Information System (INIS)

    Marucco, Arianna; Fenoglio, Ivana; Turci, Francesco; Fubini, Bice

    2013-01-01

    TiO 2 nanoparticles (NPs) are contained in different kinds of industrial products including paints, self-cleaning glasses, sunscreens. TiO 2 is also employed in photocatalysis and it has been proposed for waste water treatment. Micrometric TiO 2 is generally considered a safe material, while there is concern on the possible health effects of nanometric titania. Due to their small size NPs may migrate within the human body possibly entering in the blood stream. Therefore studies on the interaction of NPs with plasma proteins are needed. In fact, the interaction with proteins is believed to ultimately influences the NPs biological fate. Fibrinogen and albumin are two of the most abundant plasma proteins. They are involved in several important physiological functions. Furthermore, fibrinogen is known to trigger platelet adhesion and inflammation. For these reasons the study of the interaction between these protein and nanoparticles is an important step toward the understanding of the behavior of NPs in the body. In this study we investigated the interaction of albumin and fibrinogen with TiO 2 nanoparticles of different crystal phases (rutile and anatase) using an integrated set of techniques. The amount of adsorbed fibrinogen and albumin for each TiO 2 surface was investigated by using the bicinchoninic acid assay (BCA). The variation of the surface charge of the NP-protein conjugates respect to the naked NPs was used to indirectly estimate both surface coverage and reversibility of the adsorption upon dilution. Surface charge was monitored by measuring the ζ potential with a conventional electrophoretic light scattering (ELS) system. The extent of protein deformation was evaluated by Raman Spectroscopy. We found that both proteins adsorb irreversibly against electrostatic repulsion, likely undergoing conformational changes or selective orientation upon adsorption. The size of primary particles and the particles aggregation rather than the crystal phase modulate the

  1. Preparation of hydrosol suspensions of elemental and core–shell nanoparticles by co-deposition with water vapour from the gas-phase in ultra-high vacuum conditions

    International Nuclear Information System (INIS)

    Binns, Chris; Prieto, Pilar; Baker, Stephen; Howes, Paul; Dondi, Ruggero; Burley, Glenn; Lari, Leonardo; Kröger, Roland; Pratt, Andrew; Aktas, Sitki; Mellon, John K.

    2012-01-01

    We report a new method to produce liquid suspensions of nanoparticles by co-deposition with water vapour from the gas-phase in ultra-high vacuum (UHV) conditions. The water is injected from outside the vacuum as a molecular beam onto a substrate maintained at 77 K and forms an ice layer with a UHV vapour pressure. Molecular dynamics simulations confirm that the nanoparticles are soft-landed close to the surface of the growing ice layer. We show that the un-agglomerated size distribution within the liquid is similar to the gas-phase size distribution and demonstrate that the inclusion of surfactants in the injected water prevents agglomeration. The method allows the flexibility and tight size control available with gas-phase production methods to be applied to making nanoparticle suspensions with any desired properties. This is important for practical applications, especially in medicine. We have extended the method to include core–shell nanoparticles, in which there is flexible control over the core size and shell thickness and free choice of the material in either. Here, we report the production of suspensions of Cu, Ag and Au elemental nanoparticles and Fe-Au and Fe-Fe-oxide core–shell nanoparticles with diameters in the range 5–15 nm. We demonstrate the power of the method in practical applications in the case of Fe-Fe-oxide nanoparticles, which have a specific absorption rate of an applied oscillating magnetic field that is significantly higher than available Fe-oxide nanoparticle suspensions and the highest yet reported. These will thus have a very high-performance in the treatment of tumours by magnetic nanoparticle hyperthermia.

  2. Efficacy of titanium dioxide nanoparticle spray to disinfect mobile phones used by endodontist: A bacteriological study.

    Science.gov (United States)

    Palaniswamy, Udayakumar; Habeeb, Aisha; Mohsin, Mohammed

    2018-01-01

    The objectives of this study were to determine the bacterial contamination of the mobile phones that were used by the endodontist in comparison with the general dentist and also to determine the usefulness of titanium dioxide nanospray (TiO 2 NS) in mobile phone decontamination. Samples from the 60 mobile phones were taken using moist sterile swabs before, 10 min, and 1 week after the use of TiO 2 NS. Before collection of the swabs, the participants' informed consent was obtained. Samples obtained were cultured on blood agar to identify bacterial isolates. All 60 mobile phone cultures were found to be culture positive. There was a significant reduction in the mean number of colony-forming units after decontamination with TiO 2 NS ( P mobile phones may act as an important source of nosocomial pathogens and TiO 2 NS would be an effective decontaminant. Therefore, it is important for dental professionals to practice routine mobile phone disinfection protocol to reduce the chances of occurrence of nosocomial infections.

  3. Role of Carnosine and Melatonin in Ameliorating Cardiotoxicity of Titanium Dioxide Nanoparticles in the Rats

    Directory of Open Access Journals (Sweden)

    Nouf Al-Rasheed

    2015-08-01

    Full Text Available The aim of this work was to study the possible cardiotoxicity of two different doses of 50 nm nano titanium dioxide (n-TiO2 and the possible modulating effects of the use of two natural antioxidants carnosine and melatonin. The results showed that TiO2- NPs produced deleterious effects on rat cardiac tissue as confirmed by the increased levels of serum myoglobin, troponin-T and CK-MB. Increased levels of serum Inflammatory markers represented by the tumor necrosis factor alpha (TNF-α and Interleukin-6 (IL-6 was also noticed. Caspase3 and IGg were elevated compared to the control group in a dose dependant manner. treatment of the rats with Carnosine or melatonin. along with TiO2- NPs administration significantly improved most of the elevated biochemical markers. It was concluded that the use of Carnosine or melatonin could play a beneficial role against deleterious effects of TiO2- NPs

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-30

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

  5. High stable suspension of magnetite nanoparticles in ethanol by using sono-synthesized nanomagnetite in polyol medium

    International Nuclear Information System (INIS)

    Bastami, Tahereh Rohani; Entezari, Mohammad H.

    2013-01-01

    Graphical abstract: - Highlights: • The sonochemical synthesis of magnetite nanoparticles was carried out in EG without any surfactant. • The nanoparticles with sizes ∼24 nm were composed of small building blocks with sizes ∼2 nm. • The hydrophilic magnetite nanoparticles were stable in ethanol even after 8 months. • Ultrasonic intensity showed a crucial role on the obtained high stable magnetite nanoparticles in ethanol. - Abstract: The sonochemical synthesis of magnetite nanoparticles was carried out at relatively low temperature (80 °C) in ethylene glycol (EG) as a polyol solvent. The particle size was determined by transmission electron microscopy (TEM). The magnetite nanoparticles with an average size of 24 nm were composed of small building blocks with an average size of 2–3 nm and the particles exhibited nearly spherical shape. The surface characterization was investigated by using Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The stability of magnetite nanoparticles was studied in ethanol as a polar solvent. The nanoparticles showed an enhanced stability in ethanol which is due to the hydrophilic surface of the particles. The colloidal stability of magnetite nanoparticles in ethanol was monitored by UV–visible spectrophotometer. According to the results, the nanoparticles synthesized in 30 min of sonication with intensity of 35 W/cm 2 (50%) led to a maximum stability in ethanol as a polar solvent with respect to the other applied intensities. The obtained magnetite nanoparticles were stable for more than12 months

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

    KAUST Repository

    Anjum, Dalaver H.

    2013-10-01

    TiO2 nanoparticles (NPs) were prepared using flame synthesis and then characterized using transmission electron microscopy. We found that the flame method yields both crystalline TiO2 and amorphous TiO 2 NPs. TEM analysis revealed that only the crystalline TiO 2 NPs were coated with carbon. Based on this observation, we proposed a growth model for the diffusion and precipitation of carbon atoms in TiO 2 NPs. The optical properties of TiO2 NPs were investigated by performing valence electron energy loss spectrometry analysis. We observed that carbon-coated TiO2 NPs have higher absorption in the visible range due to their lower band-gap energy. © 2013 Elsevier B.V.

  7. Nanorods and nanoparticles of titanium dioxide and their use in dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Govindaraj, R., E-mail: isrogovindaraj@gmail.com; Magesh, M.; Senthil Pandian, M.; Ramasamy, P. [Department of Physics, Research Centre, SSN College of Engineering, Kalavakkam, Chennai, Tamilnadu-603 110 (India); Mukhopadhyay, Sumita [Centre of Excellence for Green Energy and sensor systems, IIEST, Howrah, West Bengal-711 103 (India)

    2016-05-23

    Mesoporous TiO{sub 2} nanorods/nanorods were successfully synthesized by hydrothermal process at 170 °C for 72 hr. The powder X-ray diffraction pattern shows large fraction of anatase phase with good crystalline behavior of the prepared materials. The specific surface area and pore volume of the synthesized material are about 84.83 m{sup 2}/g and 0.1316 cc/g respectively. The morphological results show that the TiO{sub 2} nanorods had diameter of ~ 25 nm and the length of ~ 80 nm. The nanoparticles have 20 nm in size. The current-voltage curve shows that the synthesized TiO{sub 2} nanostructure results in 36.7 % higher solar cell efficiency than commercial P25.

  8. Visible light-driven photocatalytic degradation of the organic pollutant methylene blue with hybrid palladium–fluorine-doped titanium oxide nanoparticles

    International Nuclear Information System (INIS)

    Lázaro-Navas, Sonia; Prashar, Sanjiv; Fajardo, Mariano; Gómez-Ruiz, Santiago

    2015-01-01

    The synthesis of mesoporous aggregates of titanium oxide nanoparticles (F0) is described using a very cheap and simple synthetic protocol. This consists of the reaction of titanium tetraisopropoxide and a solution of HNO 3 in water (pH 2.0) and subsequent filtration. In addition, fluorine-doped titanium oxides (F1, F2, F5 and F10) were synthesized using the same method, adding increasing amounts of NaF to the reaction mixture (avoiding the use of expensive reagents such as NH 4 F or trifluoroacetic acid). The resulting materials were calcined at different temperatures (500, 600 and 650 °C) giving particles sized between 10 and 20 nm. Furthermore, a hybrid F-doped TiO 2 with supported palladium nanoparticles of ca. 20 nm (F5-500-Pd1) was synthesized by grafting an organometallic palladium(II) salt namely [Pd(cod)Cl 2 ] (cod = 1,5-cyclooctadiene). Photocatalytic studies of the degradation of methylene blue (MB) were carried out under UV light using all the synthesized material (non-doped an F-doped TiO 2 ), observing that the increase in the quantity of fluorine has a positive effect on the photocatalytic activity. F5-500 is apparently the material which has the most convenient structural properties (in terms of surface area and anatase/rutile ratio) and thus a higher photocatalytic activity. The hybrid material F-doped TiO 2 –Pd nanoparticles (F5-500-Pd1) has a lower band gap value than F5-500, and thus photocatalytic degradation of MB under LED visible light was achieved using F5-500-Pd1 as photocatalyst

  9. Visible light-driven photocatalytic degradation of the organic pollutant methylene blue with hybrid palladium–fluorine-doped titanium oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lázaro-Navas, Sonia; Prashar, Sanjiv; Fajardo, Mariano; Gómez-Ruiz, Santiago, E-mail: santiago.gomez@urjc.es [Universidad Rey Juan Carlos, Departamento de Biología y Geología, Física y Química Inorgánica, ESCET (Spain)

    2015-02-15

    The synthesis of mesoporous aggregates of titanium oxide nanoparticles (F0) is described using a very cheap and simple synthetic protocol. This consists of the reaction of titanium tetraisopropoxide and a solution of HNO{sub 3} in water (pH 2.0) and subsequent filtration. In addition, fluorine-doped titanium oxides (F1, F2, F5 and F10) were synthesized using the same method, adding increasing amounts of NaF to the reaction mixture (avoiding the use of expensive reagents such as NH{sub 4}F or trifluoroacetic acid). The resulting materials were calcined at different temperatures (500, 600 and 650 °C) giving particles sized between 10 and 20 nm. Furthermore, a hybrid F-doped TiO{sub 2} with supported palladium nanoparticles of ca. 20 nm (F5-500-Pd1) was synthesized by grafting an organometallic palladium(II) salt namely [Pd(cod)Cl{sub 2}] (cod = 1,5-cyclooctadiene). Photocatalytic studies of the degradation of methylene blue (MB) were carried out under UV light using all the synthesized material (non-doped an F-doped TiO{sub 2}), observing that the increase in the quantity of fluorine has a positive effect on the photocatalytic activity. F5-500 is apparently the material which has the most convenient structural properties (in terms of surface area and anatase/rutile ratio) and thus a higher photocatalytic activity. The hybrid material F-doped TiO{sub 2}–Pd nanoparticles (F5-500-Pd1) has a lower band gap value than F5-500, and thus photocatalytic degradation of MB under LED visible light was achieved using F5-500-Pd1 as photocatalyst.

  10. Titanium oxide (TiO2) nanoparticles in induction of apoptosis and inflammatory response in brain

    International Nuclear Information System (INIS)

    Meena, Ramovatar; Kumar, Sumit; Paulraj, R.

    2015-01-01

    The ever increasing applications of engineered nanoparticles in 21st century cause serious concern about its potential health risks on living being. Regulatory health risk assessment of such particles has become mandatory for the safe use of nanomaterials in consumer products and medicines. In order to study the mechanism underlying the effects of nano-TiO 2 (TiO 2 nanoparticles) on the brain, wistar rats were administrated intravenously with various doses of nano-TiO 2 (21 nm) through the caudal vein, once a week for 4 weeks and different parameters such as bioaccumulation of nano-TiO 2 , oxidative stress-mediated response, level of inflammatory markers such as NF-κB (p65), HSP 60, p38, nitric oxide, IFN-γ and TNF-α, and level of neurochemicals in brain as well as DNA damage and expression of apoptosis markers (p53, Bax, Bcl-2, and cyto c) were evaluated. Results show that the concentration of nano-TiO 2 in the brain increased with increasing the doses of nano-TiO 2 . Oxidative stress and injury of the brain occurred as nano-TiO 2 appeared to trigger a cascade of reactions such as inflammation, lipid peroxidation, decreases the activities of antioxidative enzymes and melatonin level, the reduction of glutamic acid, downregulated levels of acetylcholinesterase activities, and the increase in caspase-3 activity (a biomarker of apoptosis), DNA fragmentation, and apoptosis. It may be concluded that nano-TiO 2 induces oxidative stress that leads to activation of inflammatory cytokines and an alteration in the level of neurotransmitters resulted in the induction of mitochondrial-mediated apoptosis

  11. Food web effects of titanium dioxide nanoparticles in an outdoor freshwater mesocosm experiment.

    Science.gov (United States)

    Jovanović, Boris; Bezirci, Gizem; Çağan, Ali Serhan; Coppens, Jan; Levi, Eti E; Oluz, Zehra; Tuncel, Eylül; Duran, Hatice; Beklioğlu, Meryem

    2016-09-01

    Over the course of 78 days, nine outdoor mesocosms, each with 1350 L capacity, were situated on a pontoon platform in the middle of a lake and exposed to 0 μg L(-1) TiO2, 25 μg L(-1) TiO2 or 250 μg L(-1) TiO2 nanoparticles in the form of E171 TiO2 human food additive five times a week. Mesocosms were inoculated with sediment, phytoplankton, zooplankton, macroinvertebrates, macrophytes and fish before exposure, ensuring a complete food web. Physicochemical parameters of the water, nutrient concentrations, and biomass of the taxa were monitored. Concentrations of 25 μg L(-1) TiO2 and 250 μg L(-1) TiO2 caused a reduction in available soluble reactive phosphorus in the mesocosms by 15 and 23%, respectively, but not in the amount of total phosphorus. The biomass of Rotifera was significantly reduced by 32 and 57% in the TiO2 25 μg L(-1) and TiO2 250 μg L(-1) treatments, respectively, when compared to the control; however, the biomass of the other monitored groups-Cladocera, Copepoda, phytoplankton, macrophytes, chironomids and fish-remained unaffected. In conclusion, environmentally relevant concentrations of TiO2 nanoparticles may negatively affect certain parameters and taxa of the freshwater lentic aquatic ecosystem. However, these negative effects are not significant enough to affect the overall function of the ecosystem, as there were no cascade effects leading to a major change in its trophic state or primary production.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-15

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

  14. A study of chitosan hydrogel with embedded mesoporous silica nanoparticles loaded by ibuprofen as a dual stimuli-responsive drug release system for surface coating of titanium implants.

    Science.gov (United States)

    Zhao, Pengkun; Liu, Hongyu; Deng, Hongbing; Xiao, Ling; Qin, Caiqin; Du, Yumin; Shi, Xiaowen

    2014-11-01

    In this study, the complex pH and electro responsive system made of chitosan hydrogel with embedded mesoporous silica nanoparticles (MSNs) was evaluated as a tunable drug release system. As a model drug, ibuprofen (IB) was used; its adsorption in MSNs was evidenced by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TG). In order to prepare the complex drug release system, the loaded particles IB-MSNs were dispersed in chitosan solution and then the complex IB-MSNs/chitosan film of 2mm thickness was deposited as a hydrogel on the titanium electrode. The codeposition of components was performed under a negative biasing of the titanium electrode at -0.75 mA/cm2 current density during 30 min. The IB release from the IB-MSNs/chitosan hydrogel film was studied as dependent on pH of the release media and electrical conditions applied to the titanium plate. When incubating the complex hydrogel film in buffers with different pH, the IB release followed a near zero-order profile, though its kinetics varied. Compared to the spontaneous IB release from the hydrogel in 0.9% NaCl solution (at 0 V), the application of negative biases to the coated titanium plate had profound effluences on the release behavior. The release was retarded when -1.0 V was applied, but a faster kinetics was observed at -5.0 V. These results imply that a rapid, mild and facile electrical process for covering titanium implants by complex IB-MSNs/chitosan hydrogel films can be used for controlled drug delivery applications. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-15

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

  16. Characterization of titanium dioxide nanoparticles modified with polyacrylic acid and H2O2 for use as a novel radiosensitizer.

    Science.gov (United States)

    Morita, Kenta; Miyazaki, Serika; Numako, Chiya; Ikeno, Shinya; Sasaki, Ryohei; Nishimura, Yuya; Ogino, Chiaki; Kondo, Akihiko

    2016-12-01

    An induction of polyacrylic acid-modified titanium dioxide with hydrogen peroxide nanoparticles (PAA-TiO 2 /H 2 O 2 NPs) to a tumor exerted a therapeutic enhancement of X-ray irradiation in our previous study. To understand the mechanism of the radiosensitizing effect of PAA-TiO 2 /H 2 O 2 NPs, analytical observations that included DLS, FE-SEM, FT-IR, XAFS, and Raman spectrometry were performed. In addition, highly reactive oxygen species (hROS) which PAA-TiO 2 /H 2 O 2 NPs produced with X-ray irradiation were quantified by using a chemiluminescence method and a EPR spin-trapping method. We found that PAA-TiO 2 /H 2 O 2 NPs have almost the same characteristics as PAA-TiO 2 . Surprisingly, there were no significant differences in hROS generation. However, the existence of H 2 O 2 was confirmed in PAA-TiO 2 /H 2 O 2 NPs, because spontaneous hROS production was observed w/o X-ray irradiation. In addition, PAA-TiO 2 /H 2 O 2 NPs had a curious characteristic whereby they absorbed H 2 O 2 molecules and released them gradually into a liquid phase. Based on these results, the H 2 O 2 was continuously released from PAA-TiO 2 /H 2 O 2 NPs, and then released H 2 O 2 assumed to be functioned indirectly as a radiosensitizing factor.

  17. NMR-based metabonomic study of the sub-acute toxicity of titanium dioxide nanoparticles in rats after oral administration

    Science.gov (United States)

    Bu, Qian; Yan, Guangyan; Deng, Pengchi; Peng, Feng; Lin, Hongjun; Xu, Youzhi; Cao, Zhixing; Zhou, Tian; Xue, Aiqin; Wang, Yanli; Cen, Xiaobo; Zhao, Ying-Lan

    2010-03-01

    As titanium dioxide nanoparticles (TiO2 NPs) are widely used commercially, their potential toxicity on human health has attracted particular attention. In the present study, the oral toxicological effects of TiO2 NPs (dosed at 0.16, 0.4 and 1 g kg - 1, respectively) were investigated using conventional approaches and metabonomic analysis in Wistar rats. Serum chemistry, hematology and histopathology examinations were performed. The urine and serum were investigated by 1H nuclear magnetic resonance (NMR) using principal components and partial least squares discriminant analysis. The metabolic signature of urinalysis in TiO2 NP-treated rats showed increases in the levels of taurine, citrate, hippurate, histidine, trimethylamine-N-oxide (TMAO), citrulline, α-ketoglutarate, phenylacetylglycine (PAG) and acetate; moreover, decreases in the levels of lactate, betaine, methionine, threonine, pyruvate, 3-D-hydroxybutyrate (3-D-HB), choline and leucine were observed. The metabonomics analysis of serum showed increases in TMAO, choline, creatine, phosphocholine and 3-D-HB as well as decreases in glutamine, pyruvate, glutamate, acetoacetate, glutathione and methionine after TiO2 NP treatment. Aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) were elevated and mitochondrial swelling in heart tissue was observed in TiO2 NP-treated rats. These findings indicate that disturbances in energy and amino acid metabolism and the gut microflora environment may be attributable to the slight injury to the liver and heart caused by TiO2 NPs. Moreover, the NMR-based metabolomic approach is a reliable and sensitive method to study the biochemical effects of nanomaterials.

  18. NMR-based metabonomic study of the sub-acute toxicity of titanium dioxide nanoparticles in rats after oral administration

    International Nuclear Information System (INIS)

    Bu Qian; Lin Hongjun; Xu Youzhi; Cao Zhixing; Zhou Tian; Zhao Yinglan; Yan Guangyan; Cen Xiaobo; Deng Pengchi; Peng Feng; Xue Aiqin; Wang Yanli

    2010-01-01

    As titanium dioxide nanoparticles (TiO 2 NPs) are widely used commercially, their potential toxicity on human health has attracted particular attention. In the present study, the oral toxicological effects of TiO 2 NPs (dosed at 0.16, 0.4 and 1 g kg -1 , respectively) were investigated using conventional approaches and metabonomic analysis in Wistar rats. Serum chemistry, hematology and histopathology examinations were performed. The urine and serum were investigated by 1 H nuclear magnetic resonance (NMR) using principal components and partial least squares discriminant analysis. The metabolic signature of urinalysis in TiO 2 NP-treated rats showed increases in the levels of taurine, citrate, hippurate, histidine, trimethylamine-N-oxide (TMAO), citrulline, α-ketoglutarate, phenylacetylglycine (PAG) and acetate; moreover, decreases in the levels of lactate, betaine, methionine, threonine, pyruvate, 3-D-hydroxybutyrate (3-D-HB), choline and leucine were observed. The metabonomics analysis of serum showed increases in TMAO, choline, creatine, phosphocholine and 3-D-HB as well as decreases in glutamine, pyruvate, glutamate, acetoacetate, glutathione and methionine after TiO 2 NP treatment. Aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) were elevated and mitochondrial swelling in heart tissue was observed in TiO 2 NP-treated rats. These findings indicate that disturbances in energy and amino acid metabolism and the gut microflora environment may be attributable to the slight injury to the liver and heart caused by TiO 2 NPs. Moreover, the NMR-based metabolomic approach is a reliable and sensitive method to study the biochemical effects of nanomaterials.

  19. NMR-based metabonomic study of the sub-acute toxicity of titanium dioxide nanoparticles in rats after oral administration

    Energy Technology Data Exchange (ETDEWEB)

    Bu Qian; Lin Hongjun; Xu Youzhi; Cao Zhixing; Zhou Tian; Zhao Yinglan [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Yan Guangyan; Cen Xiaobo [National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Deng Pengchi [Analytical and Testing Center, Sichuan University, Chengdu 610041 (China); Peng Feng [Department of Thoracic Oncology of Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Xue Aiqin [Institute of Bioengineering, Zhejiang Sci-Tech University Road 2, Xiasha, Hangzhou 310018 (China); Wang Yanli, E-mail: alancenxb@sina.com [Tianjin Children' s Hospital, Tianjin 300074 (China)

    2010-03-26

    As titanium dioxide nanoparticles (TiO{sub 2} NPs) are widely used commercially, their potential toxicity on human health has attracted particular attention. In the present study, the oral toxicological effects of TiO{sub 2} NPs (dosed at 0.16, 0.4 and 1 g kg{sup -1}, respectively) were investigated using conventional approaches and metabonomic analysis in Wistar rats. Serum chemistry, hematology and histopathology examinations were performed. The urine and serum were investigated by {sup 1}H nuclear magnetic resonance (NMR) using principal components and partial least squares discriminant analysis. The metabolic signature of urinalysis in TiO{sub 2} NP-treated rats showed increases in the levels of taurine, citrate, hippurate, histidine, trimethylamine-N-oxide (TMAO), citrulline, {alpha}-ketoglutarate, phenylacetylglycine (PAG) and acetate; moreover, decreases in the levels of lactate, betaine, methionine, threonine, pyruvate, 3-D-hydroxybutyrate (3-D-HB), choline and leucine were observed. The metabonomics analysis of serum showed increases in TMAO, choline, creatine, phosphocholine and 3-D-HB as well as decreases in glutamine, pyruvate, glutamate, acetoacetate, glutathione and methionine after TiO{sub 2} NP treatment. Aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) were elevated and mitochondrial swelling in heart tissue was observed in TiO{sub 2} NP-treated rats. These findings indicate that disturbances in energy and amino acid metabolism and the gut microflora environment may be attributable to the slight injury to the liver and heart caused by TiO{sub 2} NPs. Moreover, the NMR-based metabolomic approach is a reliable and sensitive method to study the biochemical effects of nanomaterials.

  20. ZnO nanoparticle incorporated nanostructured metallic titanium for increased mesenchymal stem cell response and antibacterial activity

    Science.gov (United States)

    Elizabeth, Elmy; Baranwal, Gaurav; Krishnan, Amit G.; Menon, Deepthy; Nair, Manitha

    2014-03-01

    Recent trends in titanium implants are towards the development of nanoscale topographies that mimic the nanoscale properties of bone tissue. Although the nanosurface promotes the integration of osteoblast cells, infection related problems can also occur, leading to implant failure. Therefore it is imperative to reduce bacterial adhesion on an implant surface, either with or without the use of drugs/antibacterial agents. Herein, we have investigated two different aspects of Ti surfaces in inhibiting bacterial adhesion and concurrently promoting mammalian cell adhesion. These include (i) the type of nanoscale topography (Titania nanotube (TNT) and Titania nanoleaf (TNL)) and (ii) the presence of an antibacterial agent like zinc oxide nanoparticles (ZnOnp) on Ti nanosurfaces. To address this, periodically arranged TNT (80-120 nm) and non-periodically arranged TNL surfaces were generated by the anodization and hydrothermal techniques respectively, and incorporated with ZnOnp of different concentrations (375 μM, 750 μM, 1.125 mM and 1.5 mM). Interestingly, TNL surfaces decreased the adherence of staphylococcus aureus while increasing the adhesion and viability of human osteosarcoma MG63 cell line and human mesenchymal stem cells, even in the absence of ZnOnp. In contrast, TNT surfaces exhibited an increased bacterial and mammalian cell adhesion. The influence of ZnOnp on these surfaces in altering the bacterial and cell adhesion was found to be concentration dependent, with an optimal range of 375-750 μM. Above 750 μM, although bacterial adhesion was reduced, cellular viability was considerably affected. Thus our study helps us to infer that nanoscale topography by itself or its combination with an optimal concentration of antibacterial ZnOnp would provide a differential cell behavior and thereby a desirable biological response, facilitating the long term success of an implant.

  1. Effects of titanium dioxide nanoparticles isolated from confectionery products on the metabolic stress pathway in human lung fibroblast cells.

    Science.gov (United States)

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

    2015-04-01

    Titanium dioxide (TiO2) is a common additive in many foods, pigments, personal care products, and other consumer products used in daily life. Despite the widespread use of nanoscale TiO2 and composites of nanoscale TiO2 in the food industry, there is a serious lack of awareness of the toxicity of TiO2 nanoparticles (NPs) among consumers and manufacturers. There is an urgent need for toxicological studies of TiO2 NPs. TiO2 food additives separated from marketed foods were characterized by transmission electron microscopy. In addition, the effects of TiO2 NPs on metabolic stress in WI-38 cells were analyzed. Cell viability, total ROS, mitochondrial transmembrane potential (ΔψM), cell cycle, and metabolism-related gene expression were analyzed. The results indicate that TiO2 NPs have a significant concentration-dependent toxic effect in lung cells. The ΔψM, the intracellular ROS level, and the stages of the WI-38 cell cycle were altered by increasing TiO2 concentrations after exposure for 24 and 48 h relative to the control. Cytochrome P450 1A, GSTM3, and glutathione S-transferase A4 upregulation in response to the TiO2 NPs was observed. These findings suggest that the toxicity of TiO2 from confectionery products in WI-38 cells may be mediated through an increase in oxidative stress. The results of this study clearly demonstrate the nanotoxicological effects of TiO2 on WI-38 cells and will be useful for nanotoxicological indexing.

  2. Agglomeration and sedimentation of titanium dioxide nanoparticles (n-TiO{sub 2}) in synthetic and real waters

    Energy Technology Data Exchange (ETDEWEB)

    Brunelli, Andrea [University Ca' Foscari Venice, Department of Environmental Sciences, Informatics and Statistics (Italy); Pojana, Giulio [University Ca' Foscari Venice, Department of Philosophy and Cultural Heritage (Italy); Callegaro, Sarah; Marcomini, Antonio, E-mail: marcom@unive.it [University Ca' Foscari Venice, Department of Environmental Sciences, Informatics and Statistics (Italy)

    2013-06-15

    The recent detection of titanium dioxide nanoparticles (n-TiO{sub 2}) in wastewaters raised concerns about its fate in the aquatic environment, which is related to its mobility through water bodies. Laboratory experiments of n-TiO{sub 2} (particle size distribution: 10-65 nm) dispersed into both synthetic and real aqueous solutions under environmentally realistic concentrations (0.01, 0.1, 1 and 10 mg/l) were conducted over a time of 50 h to mimic duration of ecotoxicological tests. Agglomeration and sedimentation behaviour were measured under controlled conditions of salinity (0-35 Per-Mille-Sign ), ionic composition and strength, pH and dissolved organic carbon (DOC). Physico-chemical parameters and particle agglomeration in the dispersions were investigated by transmission electron microscopy, Brunauer, Emmett and Teller method and dynamic light scattering. A fluorescence spectrophotometer operating in the nephelometric mode was employed to obtain the sedimentation rates of n-TiO{sub 2}. The overall results showed that agglomeration and sedimentation of n-TiO{sub 2} were affected mainly by the initial concentration. Sedimentation data fitted satisfactorily (R{sup 2} in the range of 0.74-0.98; average R{sup 2}: 0.90) with a first-order kinetic equation.The settling rate constant, k, increased by approx. one order of magnitude by moving from the lowest to the highest concentration, resulting very similar especially for all dispersions at 1(k = 8 Multiplication-Sign 10{sup -6} s{sup -1}) and 10 mg/l (k = 2 Multiplication-Sign 10{sup -5} s{sup -1}) n-TiO{sub 2}, regardless the ionic strength and composition of dispersions. The implication of these results on toxicological testing is discussed.

  3. ZnO nanoparticle incorporated nanostructured metallic titanium for increased mesenchymal stem cell response and antibacterial activity

    International Nuclear Information System (INIS)

    Elizabeth, Elmy; Baranwal, Gaurav; Krishnan, Amit G; Menon, Deepthy; Nair, Manitha

    2014-01-01

    Recent trends in titanium implants are towards the development of nanoscale topographies that mimic the nanoscale properties of bone tissue. Although the nanosurface promotes the integration of osteoblast cells, infection related problems can also occur, leading to implant failure. Therefore it is imperative to reduce bacterial adhesion on an implant surface, either with or without the use of drugs/antibacterial agents. Herein, we have investigated two different aspects of Ti surfaces in inhibiting bacterial adhesion and concurrently promoting mammalian cell adhesion. These include (i) the type of nanoscale topography (Titania nanotube (TNT) and Titania nanoleaf (TNL)) and (ii) the presence of an antibacterial agent like zinc oxide nanoparticles (ZnOnp) on Ti nanosurfaces. To address this, periodically arranged TNT (80–120 nm) and non-periodically arranged TNL surfaces were generated by the anodization and hydrothermal techniques respectively, and incorporated with ZnOnp of different concentrations (375 μM, 750 μM, 1.125 mM and 1.5 mM). Interestingly, TNL surfaces decreased the adherence of staphylococcus aureus while increasing the adhesion and viability of human osteosarcoma MG63 cell line and human mesenchymal stem cells, even in the absence of ZnOnp. In contrast, TNT surfaces exhibited an increased bacterial and mammalian cell adhesion. The influence of ZnOnp on these surfaces in altering the bacterial and cell adhesion was found to be concentration dependent, with an optimal range of 375−750 μM. Above 750 μM, although bacterial adhesion was reduced, cellular viability was considerably affected. Thus our study helps us to infer that nanoscale topography by itself or its combination with an optimal concentration of antibacterial ZnOnp would provide a differential cell behavior and thereby a desirable biological response, facilitating the long term success of an implant. (paper)

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

    Science.gov (United States)

    2013-01-01

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

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

    Science.gov (United States)

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

    2017-06-01

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

  6. Agglomeration and sedimentation of titanium dioxide nanoparticles (n-TiO2) in synthetic and real waters

    International Nuclear Information System (INIS)

    Brunelli, Andrea; Pojana, Giulio; Callegaro, Sarah; Marcomini, Antonio

    2013-01-01

    The recent detection of titanium dioxide nanoparticles (n-TiO 2 ) in wastewaters raised concerns about its fate in the aquatic environment, which is related to its mobility through water bodies. Laboratory experiments of n-TiO 2 (particle size distribution: 10–65 nm) dispersed into both synthetic and real aqueous solutions under environmentally realistic concentrations (0.01, 0.1, 1 and 10 mg/l) were conducted over a time of 50 h to mimic duration of ecotoxicological tests. Agglomeration and sedimentation behaviour were measured under controlled conditions of salinity (0–35 ‰), ionic composition and strength, pH and dissolved organic carbon (DOC). Physico-chemical parameters and particle agglomeration in the dispersions were investigated by transmission electron microscopy, Brunauer, Emmett and Teller method and dynamic light scattering. A fluorescence spectrophotometer operating in the nephelometric mode was employed to obtain the sedimentation rates of n-TiO 2 . The overall results showed that agglomeration and sedimentation of n-TiO 2 were affected mainly by the initial concentration. Sedimentation data fitted satisfactorily (R 2 in the range of 0.74–0.98; average R 2 : 0.90) with a first-order kinetic equation.The settling rate constant, k, increased by approx. one order of magnitude by moving from the lowest to the highest concentration, resulting very similar especially for all dispersions at 1(k = 8 × 10 −6 s −1 ) and 10 mg/l (k = 2 × 10 −5 s −1 ) n-TiO 2 , regardless the ionic strength and composition of dispersions. The implication of these results on toxicological testing is discussed.

  7. Genotoxicity, potential cytotoxicity and cell uptake of titanium dioxide nanoparticles in the marine fish Trachinotus carolinus (Linnaeus, 1766)

    Energy Technology Data Exchange (ETDEWEB)

    Vignardi, Caroline P., E-mail: carolpatvig@usp.br [Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, Praça do Oceanogáfico 191, Cidade Universitária, Butantã, São Paulo, SP 05508900 (Brazil); Hasue, Fabio M., E-mail: humbigutis@gmail.com [Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, Praça do Oceanogáfico 191, Cidade Universitária, Butantã, São Paulo, SP 05508900 (Brazil); Sartório, Priscila V., E-mail: pri.sartorio@gmail.com [Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, Praça do Oceanogáfico 191, Cidade Universitária, Butantã, São Paulo, SP 05508900 (Brazil); Cardoso, Caroline M., E-mail: camargonato@gmail.com [Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, Praça do Oceanogáfico 191, Cidade Universitária, Butantã, São Paulo, SP 05508900 (Brazil); Machado, Alex S.D., E-mail: mamiferomarinho@gmail.com [Faculty of Veterinary Medicine, Integrated College North of Minas Osmane Barbosa Avenue, 11111, JK, Montes Claros, MG 39404006 (Brazil); and others

    2015-01-15

    Highlights: • TiO{sub 2}–NP cytogenotoxicity and cell uptake in marine fish was studied. • TiO{sub 2}–NP suspension was in primary particle, agglomerated and aggregated form. • TiO{sub 2}–NP genotoxicity was time/dose dependent and may induce cell uptake. • Methodology proved to be efficient for evaluating the toxic effect of TiO{sub 2}–NP. - Abstract: Nanoparticles have physicochemical characteristics that make them useful in areas such as science, technology, medicine and in products of everyday use. Recently the manufacture and variety of these products has grown rapidly, raising concerns about their impact on human health and the environment. Adverse effects of exposure to nanoparticles have been reported for both terrestrial and aquatic organisms, but the toxic effects of the substances on marine organisms remain poorly understood. The main aim of this study was to evaluate the genotoxicity of TiO{sub 2}–NP in the marine fish Trachinotus carolinus, through cytogenotoxic methods. The fish received two different doses of 1.5 μg and 3.0 μg–TiO{sub 2}–NP g{sup −1} by intraperitoneal injection. Blood samples were collected to analyze erythrocyte viability using the Trypan Blue exclusion test, comet assay (pH > 13), micronucleus (MN) and other erythrocyte nuclear abnormalities (ENA) 24, 48 and 72 h after injection. The possible cell uptake of TiO{sub 2}–NP in fish injected with the higher dose was investigated after 72 h using transmission electron microscopy (TEM). The results showed that TiO{sub 2}–NP is genotoxic and potentially cytotoxic for this species, causing DNA damage, inducing the formation of MN and other ENA, and decreasing erythrocyte viability. TEM examination revealed that cell uptake of TiO{sub 2}–NP was mainly in the kidney, liver, gills and to a lesser degree in muscle. To the extent of the authors’ knowledge, this is the first in vivo study of genotoxicity and other effects of TiO{sub 2}–NP in a marine fish.

  8. Iron Oxide and Titanium Dioxide Nanoparticle Effects on Plant Performance and Root Associated Microbes

    Directory of Open Access Journals (Sweden)

    David J. Burke

    2015-10-01

    Full Text Available In this study, we investigated the effect of positively and negatively charged Fe3O4 and TiO2 nanoparticles (NPs on the growth of soybean plants (Glycine max. and their root associated soil microbes. Soybean plants were grown in a greenhouse for six weeks after application of different amounts of NPs, and plant growth and nutrient content were examined. Roots were analyzed for colonization by arbuscular mycorrhizal (AM fungi and nodule-forming nitrogen fixing bacteria using DNA-based techniques. We found that plant growth was significantly lower with the application of TiO2 as compared to Fe3O4 NPs. The leaf carbon was also marginally significant lower in plants treated with TiO2 NPs; however, leaf phosphorus was reduced in plants treated with Fe3O4. We found no effects of NP type, concentration, or charge on the community structure of either rhizobia or AM fungi colonizing plant roots. However, the charge of the Fe3O4 NPs affected both colonization of the root system by rhizobia as well as leaf phosphorus content. Our results indicate that the type of NP can affect plant growth and nutrient content in an agriculturally important crop species, and that the charge of these particles influences the colonization of the root system by nitrogen-fixing bacteria.

  9. Effect of titanium dioxide nanoparticle addition into orthodontic adhesive resin on enamel microhardness

    Science.gov (United States)

    Andriani, A.; Krisnawati; Purwanegara, M. K.

    2017-08-01

    White spots are an early sign of enamel demineralization, which may lead to development of dental caries. Enamel demineralization can be determined by examining the microhardness number of the enamel. Addition of antibacterial agents such as TiO2 nanoparticles into the orthodontic adhesive (TiO2 nanocomposite) is expected to prevent enamel demineralization. The objective of this study is to evaluate the effect of TiO2 nanocomposites in maintaining enamel microhardness around orthodontic brackets. The bracket was bonded to the premolar using Transbond XT (group 1), 1% TiO2 nanocomposites (group 2), and 2% TiO2 nanocomposites (group 3). Group 4 was the control group, and it was not given any treatment prior to the microhardness test. The samples of groups 1, 2, and 3 were soaked in BHI solution containing Streptococcus mutans, and then stored in an incubator at 37°C for 30 days. Demineralizations were determined on cross-sectioned tooth 100μm and 200μm cervical to the bracket by the Vickers microhardness test. The microhardness values were significantly different between every group, with the highest value obtained for control group, followed by the 2% TiO2 nanocomposite group, 1% TiO2 nanocomposite group, and then the Transbond XT group. The results of this study reveal that 2% TiO2 nanocomposites have the ability to maintain enamel microhardness around the orthodontic bracket.

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

    Science.gov (United States)

    Galletti, Andrea; Seo, Seokju; Joo, Sung Hee; Su, Chunming; Blackwelder, Pat

    2016-10-01

    Increased manufacture of TiO 2 nanoproducts has caused concern about the potential toxicity of these products to the environment and in public health. Identification and confirmation of the presence of TiO 2 nanoparticles derived from consumer products as opposed to industrial TiO 2 NPs warrant examination in exploring the significance of their release and resultant impacts on the environment. To this end, we examined the significance of the release of these particles and their toxic effect on the marine diatom algae Thalassiosira pseudonana. Our results indicate that nano-TiO 2 sunscreen and toothpaste exhibit more toxicity in comparison to industrial TiO 2 and inhibited the growth of the marine diatom T. pseudonana. This inhibition was proportional to the exposure time and concentrations of nano-TiO 2 . Our findings indicate a significant effect, and therefore, further research is warranted in evaluation and assessment of the toxicity of modified nano-TiO 2 derived from consumer products and their physicochemical properties.

  11. Antibacterial mechanisms of a novel type picosecond laser-generated silver-titanium nanoparticles and their toxicity to human cells

    Directory of Open Access Journals (Sweden)

    Korshed P

    2017-12-01

    hours of co-culture with human cells, suggesting a possible adaptive process in the cells had occurred. We conclude that picosecond laser-generated Ag-TiO2 NPs have a broad spectrum of antibacterial effect, including against the drug-resistant strain, with multiple underlying molecular mechanisms and low human cell toxicity. The antimicrobial properties of the new type of picoseconds laser-generated Ag-TiO2 compound NPs could have potential biomedical applications. Keywords: silver-titanium nanoparticles, bactericidal, picoseconds laser, reactive oxygen species, cytotoxicity, compound nanoparticles, methicillin-resistant Staphylococcus aureus

  12. Enhanced antimicrobial efficacy of thermal-reduced silver nanoparticles supported by titanium dioxide.

    Science.gov (United States)

    Chen, Yen-Chi; Yu, Kuo-Pin

    2017-06-01

    The antimicrobial efficacy of silver nanoparticles (AgNPs) is influenced by many factors, including the particle size, AgNP oxidation state and support materials. In this study, AgNPs are synthesized and supported by two types of TiO 2 powders (P25 and Merck TiO 2 ) using two heat-treatment temperatures (120 and 200°C). The formation of well-dispersed AgNPs with diameters ranging from 3.2 to 5.7nm was confirmed using transmission electron microscopy. X-ray photoelectron spectroscopy and X-ray diffraction indicated that the majority of the AgNPs were reduced from Ag + to Ag 0 at 200°C. The AgNP antimicrobial activity was determined by the zone of inhibition against three fungi, A. niger, P. spinulosum and S. chartarum, and two bacteria, E. coli (Gram-negative) and S. epidermidis (Gram-positive). The antimicrobial activity of metallic AgNPs was more pronounced than that of silver nitrate and some antimicrobial drugs. The AgNPs exhibited optimal antimicrobial efficacy when the AgNP dispersion on the surface of TiO 2 was in the region between 0.2 and 0.7μg-Ag/m 2 . The minimum (critical) AgNP concentrations needed to inhibit the growth of bacteria (E. coli) and fungi (A. niger) were 13.48 and 25.4μg/mL, respectively. The results indicate that AgNPs/TiO 2 nanocomposites are a promising disinfectant against both bacteria and fungi. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Effects of aspect ratio and concentration on rheology of epoxy suspensions containing model plate-like nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    White, K. L.; Takahara, A. [International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan); Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka 819-0395 (Japan); Hawkins, S.; Sue, H.-J., E-mail: hjsue@tamu.edu [Department of Materials Science and Engineering, Texas A& M University, College Station, Texas 77843 (United States); Miyamoto, M. [Kaneka US Materials Research Center, Kaneka America Holdings, Inc., College Station, Texas 77843 (United States)

    2015-12-15

    Hexagonal 2-dimensional α-zirconium phosphate crystals were prepared with lateral diameters ranging from 110 nm to 1.5 μm to investigate the effect of particle size on suspension rheology. The nanoplatelets were exfoliated to individual sheets with monodisperse thickness and dispersed in a Newtonian epoxy fluid. The steady shear response of dilute and semi-dilute suspensions was measured and compared to expressions obtained from theory for infinitely dilute suspensions. For suspensions containing the smaller nanoplatelets, aspect ratio ∼160, the low shear rate viscosity and transition to shear thinning behavior were well described by theory for loadings up to 0.5 vol. %. The agreement was improved by assuming a moderate polydispersity in lateral diameter, ∼30%–50%, which is consistent with experimental observation. For the higher aspect ratio nanoplatelets, good agreement between theory and experiment was observed only at high shear rates. At lower shear rate, theory consistently over-predicted viscosity, which was attributed to a progressive shift to non-isotropic initial conditions with increasing particle size. The results suggest that at a fixed Peclet number, there is an increasing tendency for the nanoplatelets to form transient, local stacks as particle size increases. The largest particles, aspect ratio ∼2200, showed unusual shear thinning and thickening behaviors that were attributed to particle flexibility. The findings demonstrate the surprising utility of theory for infinitely dilute suspensions to interpret, and in some cases quantitatively describe, the non-Newtonian viscosity of real suspensions containing high aspect ratio plate-like particles. A simple framework is proposed to interpret deviations from ideal behavior based on the local and collective behavior of the suspended nanoplatelets.

  14. Quantitative biokinetic analysis of radioactively labelled, inhaled Titanium dioxide Nanoparticles in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Kreyling, Wolfgang G.; Wenk, Alexander; Semmler-Behnke, Manuela [Helmholtz Zentrum Muenchen, Deutsches Forschungszentrum fuer Gesundheit und Umwelt GmbH (Germany). Inst. fuer Lungenbiologie und Erkrankungen, Netzwerk Nanopartikel und Gesundheit

    2010-09-15

    The aim of this project was the determination of the biokinetics of TiO{sub 2} nanoparticles (NP) in the whole body of healthy adult rats after NP administration to the respiratory tract - either via inhalation or instillation. We developed an own methodology to freshly synthesize and aerosolize TiO{sub 2}-NP in our lab for the use of inhalation studies. These NP underwent a detailed physical and chemical characterization providing pure polycrystalline anatase TiO{sub 2}-NP of about 20 nm (geometric standard deviation 1.6) and a specific surface area of 270 m{sup 2}/g. In addition, we developed techniques for sufficiently stable radioactive {sup 48}V labelling of the TiO{sub 2} NP. The kinetics of solubility of {sup 48}V was thoroughly determined. The methodology of quantitative biokinetics allows for a quantitative balance of the retained and excreted NP in control of the administered NP dose and provides a much more precise determination of NP fractions and concentrations of NP in organs and tissues of interest as compared to spotting biokinetics studies. Small fractions of TiO{sub 2}-NP translocate across the air-blood-barrier and accumulate in secondary target organs, soft tissue and skeleton. The amount of translocated TiO{sub 2}-NP is approximately 2% of TiO{sub 2}-NP deposited in the lungs. A prominent fraction of these translocated TiO{sub 2}-NP was found in the remainder. Smaller amounts of TiO{sub 2}-NP accumulate in secondary organs following particular kinetics. TiO{sub 2}-NP translocation was grossly accomplished within the first 2-4 hours after inhalation followed by retention in all organs and tissues studied without any detectable clearance of these biopersistent TiO{sub 2}-NP within 28 days. Therefore, our data suggest crossing of the air-blood-barrier of the lungs and subsequent accumulation in secondary organs and tissues depends on the NP material and its physico-chemical properties. Furthermore, we extrapolate that during repeated or chronic

  15. Quantitative biokinetic analysis of radioactively labelled, inhaled Titanium dioxide Nanoparticles in a rat model

    International Nuclear Information System (INIS)

    Kreyling, Wolfgang G.; Wenk, Alexander; Semmler-Behnke, Manuela

    2010-01-01

    The aim of this project was the determination of the biokinetics of TiO 2 nanoparticles (NP) in the whole body of healthy adult rats after NP administration to the respiratory tract - either via inhalation or instillation. We developed an own methodology to freshly synthesize and aerosolize TiO 2 -NP in our lab for the use of inhalation studies. These NP underwent a detailed physical and chemical characterization providing pure polycrystalline anatase TiO 2 -NP of about 20 nm (geometric standard deviation 1.6) and a specific surface area of 270 m 2 /g. In addition, we developed techniques for sufficiently stable radioactive 48 V labelling of the TiO 2 NP. The kinetics of solubility of 48 V was thoroughly determined. The methodology of quantitative biokinetics allows for a quantitative balance of the retained and excreted NP in control of the administered NP dose and provides a much more precise determination of NP fractions and concentrations of NP in organs and tissues of interest as compared to spotting biokinetics studies. Small fractions of TiO 2 -NP translocate across the air-blood-barrier and accumulate in secondary target organs, soft tissue and skeleton. The amount of translocated TiO 2 -NP is approximately 2% of TiO 2 -NP deposited in the lungs. A prominent fraction of these translocated TiO 2 -NP was found in the remainder. Smaller amounts of TiO 2 -NP accumulate in secondary organs following particular kinetics. TiO 2 -NP translocation was grossly accomplished within the first 2-4 hours after inhalation followed by retention in all organs and tissues studied without any detectable clearance of these biopersistent TiO 2 -NP within 28 days. Therefore, our data suggest crossing of the air-blood-barrier of the lungs and subsequent accumulation in secondary organs and tissues depends on the NP material and its physico-chemical properties. Furthermore, we extrapolate that during repeated or chronic exposure to insoluble NP the translocated fraction of NP will

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

    Directory of Open Access Journals (Sweden)

    S. Austin eHammond

    2013-11-01

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

  17. Evaluation of a carbon paste electrode modified with Strontium substituted bismuth and titanium oxide nanoparticles in the toxic metal chromium (VI determination potentiometric method

    Directory of Open Access Journals (Sweden)

    Atefeh Badri

    2016-09-01

    Full Text Available Strontium substituted bismuth and titanium oxide nanoparticles with aurivillius morphology synthesized by chemical co-precipitation method and were characterized using XRD. The nanopartcles were used in the composition of the carbon paste to improve conductivity and transduction of chemical signal to electrical signal. A procedure for the determination of chromium is described based on pre-concentration of the dichromate anion at a carbon paste electrode modified. A novel potentiometric Cr6+carbon paste electrode incorporating Strontium substituted bismuth and titanium oxide nanoparticles (SSBTO. Ina acetate buffer solution of pH 5, the sensor displays a rapid and linear response for Cr6+ over the concentration range 1.0×10-5 to 1.0×10-1mol L-1 M with an anionic slope of 54.8± 0.2 mV decade ’ and a detection limit of the order of0.002 /µg ml ‘. The sensor is used for determination of Cr6+ by direct monitoring of Cr6+.The average recoveries of Cr6+at concentration levels of 0.5~40 pg/ml ’is 98.3. The electrode has a short response time (<6s and can be used for at least twenty days without any considerable divergence in potentials and the working pH range was 4.5-6.5. The proposed electrode was successfully used as an indicator for potentiometric determination of Cr6+in water sample.

  18. Impedimetric PSA aptasensor based on the use of a glassy carbon electrode modified with titanium oxide nanoparticles and silk fibroin nanofibers.

    Science.gov (United States)

    Benvidi, Ali; Banaei, Maryam; Tezerjani, Marzieh Dehghan; Molahosseini, Hosein; Jahanbani, Shahriar

    2017-12-14

    This article describes an impedimetric aptasensor for the prostate specific antigen (PSA), a widely accepted prostate cancer biomarker. A glassy carbon electrode (GCE) was modified with titanium oxide nanoparticles (TiO 2 ) and silk fibroin nanofiber (SF) composite. The aptasensor was obtained by immobilizing a PSA-binding aptamer on the AuNP-modified with 6-mercapto-1-hexanol. The single fabrication steps were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The assay has two linear response ranges (from 2.5 fg.mL -1 to 25 pg.mL -1 , and from 25 pg.mL -1 to 25 ng.mL -1 ) and a 0.8 fg.mL -1 detection limit. After optimization of experimental conditions, the sensor is highly selective for PSA over bovine serum albumin and lysozyme. It was successfully applied to the detection of PSA in spiked serum samples. Graphical abstract Schematic of the fabrication of an aptasensor for the prostate specific antigen (PSA). It is based on the use of a glassy carbon electrode modified with gold nanoparticles and titanium oxide-silk fibroin. The immobilization process of aptamer and interaction with PSA were followed by electrochemical impedance spectroscopy technique.

  19. Determination of Histamine in Silages Using Nanomaghemite Core (γ-Fe2O3-Titanium Dioxide Shell Nanoparticles Off-Line Coupled with Ion Exchange Chromatography

    Directory of Open Access Journals (Sweden)

    Natalia Cernei

    2016-09-01

    Full Text Available The presence of biogenic amines is a hallmark of degraded food and its products. Herein, we focused on the utilization of magnetic nanoparticles off-line coupled with ion exchange chromatography with post-column ninhydrin derivatization and Vis detection for histamine (Him separation and detection. Primarily, we described the synthesis of magnetic nanoparticles with nanomaghemite core (γ-Fe2O3 functionalized with titanium dioxide and, then, applied these particles to specific isolation of Him. To obtain further insight into interactions between paramagnetic particles’ (PMP surface and Him, a scanning electron microscope was employed. It was shown that binding of histamine causes an increase of relative current response of deprotonated PMPs, which confirmed formation of Him-PMPs clusters. The recovery of the isolation showed that titanium dioxide-based particles were able to bind and preconcentrate Him with recovery exceeding 90%. Finally, we successfully carried out the analyses of real samples obtained from silage. We can conclude that our modified particles are suitable for Him isolation, and thus may serve as the first isolation step of Him from biological samples, as it is demonstrated on alfalfa seed variety Tereza silage.

  20. Titanium dioxide nanoparticles enhance production of superoxide anion and alter the antioxidant system in human osteoblast cells

    Directory of Open Access Journals (Sweden)

    Niska K

    2015-02-01

    Full Text Available Karolina Niska,1 Katarzyna Pyszka,1 Cecylia Tukaj,2 Michal Wozniak,1 Marek Witold Radomski,3–5 Iwona Inkielewicz-Stepniak1 1Department of Medical Chemistry, 2Department of Electron Microscopy, Medical University of Gdansk, Gdansk, Poland; 3School of Pharmacy and Pharmaceutical Sciences, Trinity Biomedical Sciences Institute, The University of Dublin Trinity College, Dublin, Ireland; 4Kardio-Med Silesia, 5Silesian Medical University, Zabrze, Poland Abstract: Titanium dioxide (TiO2 nanoparticles (NPs are manufactured worldwide for a variety of engineering and bioengineering applications. TiO2NPs are frequently used as a material for orthopedic implants. However, to the best of our knowledge, the biocompatibility of TiO2NPs and their effects on osteoblast cells, which are responsible for the growth and remodeling of the human skeleton, have not been thoroughly investigated. In the research reported here, we studied the effects of exposing hFOB 1.19 human osteoblast cells to TiO2NPs (5–15 nm for 24 and 48 hours. Cell viability, alkaline phosphatase (ALP activity, cellular uptake of NPs, cell morphology, superoxide anion (O2•- generation, superoxide dismutase (SOD activity and protein level, sirtuin 3 (SIR3 protein level, correlation between manganese (Mn SOD and SIR, total antioxidant capacity, and malondialdehyde were measured following exposure of hFOB 1.19 cells to TiO2NPs. Exposure of hFOB 1.19 cells to TiO2NPs resulted in: (1 cellular uptake of NPs; (2 increased cytotoxicity and cell death in a time- and concentration-dependent manner; (3 ultrastructure changes; (4 decreased SOD and ALP activity; (5 decreased protein levels of SOD1, SOD2, and SIR3; (6 decreased total antioxidant capacity; (7 increased O2•- generation; and (8 enhanced lipid peroxidation (malondialdehyde level. The linear relationship between the protein level of MnSOD and SIR3 and between O2•- content and SIR3 protein level was observed. Importantly, the cytotoxic

  1. Efficacy of larvicidal activity of green synthesized titanium dioxide nanoparticles using Mangifera indica extract against blood-feeding parasites.

    Science.gov (United States)

    Rajakumar, Govindasamy; Rahuman, Abdul Abdul; Roopan, Selvaraj Mohana; Chung, Ill-Min; Anbarasan, Karunanithi; Karthikeyan, Viswanathan

    2015-02-01

    Titanium dioxide nanoparticles (TiO2 NPs) are considered to be among the best photocatalytic materials due to their long-term thermodynamic stability, strong oxidizing power, and relative non-toxicity. Nano-preparations with TiO2 NPs are currently under investigation as novel treatments for acne vulgaris, recurrent condyloma acuminata, atopic dermatitis, hyperpigmented skin lesions, and other non-dermatologic diseases. The present study was to investigate the acaricidal and larvicidal activity of synthesized TiO2 NPs utilizing leaf aqueous extract of Mangifera indica L. (Anacardiaceae) against hematophagous parasites. The anti-parasitic activity of TiO2 NPs against the larvae of Rhipicephalus (Boophilus) microplus, Hyalomma anatolicum anatolicum and Haemaphysalis bispinosa (Acari: Ixodidae), fourth instar larvae of Anopheles subpictus, and Culex quinquefasciatus (Diptera: Culicidae) were assessed. The green synthesized TiO2 NPs were analyzed by UV-Vis, FTIR, X-ray diffraction (XRD), AFM, SEM, and TEM. The XRD analysis of synthesized TiO2 NPs revealed the dominant peak at 2θ value of 27.81 which matched the 110 crystallographic plane of the rutile structure indicating the crystal structure. The FTIR spectra exhibited a prominent peak at 3,448 cm(-1) and showed OH stretching due to the alcoholic group, and the OH group may act as a capping agent. The SEM images of TiO2 NPs displayed spherical, oval in shape, individual, and some in aggregates. Characterization of the synthesized TiO2 NPs using AFM offered three-dimensional visualization and uneven surface morphology. The TEM micrograph showed agglomerates, round and slight elongation with an average size of 30 ± 5 nm. The maximum efficacy was observed in synthesized TiO2 NPs against the larvae of R. microplus, Hyalomma anatolicum anatolicum, Haemaphysalis bispinosa, A. subpictus, and Culex quinquefasciatus with LC50 value of 28.56, 33.17, 23.81, 5.84, and 4.34 mg/L, respectively. In the present study, a novel

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-15

    Highlights: • Nrf2 signals were partly responsible for the DNA damage induced by Nano-TiO{sub 2}. • Nrf2 loss could aggravate the DNA damage induced by Nano-TiO{sub 2}. • Acquired Nrf2 decreased the susceptibility to DNA damage induced by Nano-TiO{sub 2}. - Abstract: Titanium dioxide nanoparticles (Nano-TiO{sub 2}) are widely used to additives in cosmetics, pharmaceutical, paints and foods. Recent studies have demonstrated that Nano-TiO{sub 2} induces DNA damage and increased the risk of cancer and the mechanism might relate with oxidative stress. The aim of this study was to evaluate the effects of Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), an anti-oxidative mediator, on DNA damage induced by Nano-TiO{sub 2}. Wildtype, Nrf2 knockout (Nrf2(-/-)) and tert-butylhydroquinone (tBHQ) pre-treated HepG2 cells and mice were treated with Nano-TiO{sub 2}. And then the oxidative stress and DNA damage were evaluated. Our data showed that DNA damage, reactive oxygen species (ROS) generation and MDA content in Nano-TiO{sub 2} exposed cells were significantly increased than those of control in dose dependent manners. Nrf2/ARE droved the downstream genes including NAD(P)H de