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The comparative immunotoxicity of mesoporous silica nanoparticles and colloidal silica nanoparticles in mice
Lee S, Kim MS, Lee D, Kwon TK, Khang D, Yun HS, Kim SH
International Journal of Nanomedicine , 2013, DOI: http://dx.doi.org/10.2147/IJN.S39534
Abstract: omparative immunotoxicity of mesoporous silica nanoparticles and colloidal silica nanoparticles in mice Original Research (1176) Total Article Views Authors: Lee S, Kim MS, Lee D, Kwon TK, Khang D, Yun HS, Kim SH Published Date January 2013 Volume 2013:8 Pages 147 - 158 DOI: http://dx.doi.org/10.2147/IJN.S39534 Received: 24 October 2012 Accepted: 24 November 2012 Published: 07 January 2013 Soyoung Lee,1,* Mi-Sun Kim,1,* Dakeun Lee,2 Taeg Kyu Kwon,3 Dongwoo Khang,4 Hui-Suk Yun,5 Sang-Hyun Kim1 1CMRI, Laboratory of Immunotoxicology, Department of Pharmacology,School of Medicine, Kyungpook National University, Daegu, Republic of Korea; 2Department of Pathology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea; 3Department of Immunology, School of Medicine, Keimyung University, Daegu, Republic of Korea; 4School of Nano and Advanced Materials Science and Engineering, Gyeongsang National University, Jinju, Republic of Korea; 5Engineering Ceramics Department, Powder and Ceramics Division, Korea Institute of Materials Science, Changwon, Republic of Korea *These authors contributed equally to this work Background: Mesoporous silica (MPS) nanoparticles (NPs), which have a unique pore structure and extremely large surface area and pore volume, have received much attention because of their biomedical application potential. Using MPS NPs for biomedical devices requires the verification of their biocompatibility because the surface area of NPs is one of the most important determinants of toxicity, including the cellular uptake and immune response. We have previously reported that the cytotoxicity and inflammation potential of MPS NPs have been shown to be lower than those of general amorphous colloidal silica (Col) NPs in macrophages, but the low cytotoxicity does not guarantee high biocompatibility in vivo. In this study, we compared the in vivo immunotoxicity of MPS and Col NPs in the mouse model to define the effects of pore structural conditions of silica NPs. Materials and methods: Both MPS and Col NPs (2, 20, and 50 mg/kg/day) were intraperitoneally administered in female BALB/c mice for 4 weeks, and clinical toxicity, lymphocyte population, serum IgG/IgM levels, and histological changes were examined. Results: There was no overt sign of clinical toxicity in either MPS- or Col-treated mice. However, MPS NPs led to significant increases in liver and spleen weight and splenocyte proliferation. Mice treated with MPS NPs showed altered lymphocyte populations (CD3+, CD45+, CD4+, and CD8+) in the spleen, increased serum IgG and IgM levels, and histological changes. Despite slight changes in lymphocyte populations in the spleen, Col NPs did not alter other immunological factors. Conclusion: The results indicate that in vivo exposure to MPS NPs caused more damage to systemic immunity than that of Col NPs through the dysregulation of the spleen. The results for in vivo data are inconsistent with those for in vitro data, which show lower
The comparative immunotoxicity of mesoporous silica nanoparticles and colloidal silica nanoparticles in mice  [cached]
Lee S,Kim MS,Lee D,Kwon TK
International Journal of Nanomedicine , 2013,
Abstract: Soyoung Lee,1,* Mi-Sun Kim,1,* Dakeun Lee,2 Taeg Kyu Kwon,3 Dongwoo Khang,4 Hui-Suk Yun,5 Sang-Hyun Kim11CMRI, Laboratory of Immunotoxicology, Department of Pharmacology,School of Medicine, Kyungpook National University, Daegu, Republic of Korea; 2Department of Pathology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea; 3Department of Immunology, School of Medicine, Keimyung University, Daegu, Republic of Korea; 4School of Nano and Advanced Materials Science and Engineering, Gyeongsang National University, Jinju, Republic of Korea; 5Engineering Ceramics Department, Powder and Ceramics Division, Korea Institute of Materials Science, Changwon, Republic of Korea*These authors contributed equally to this workBackground: Mesoporous silica (MPS) nanoparticles (NPs), which have a unique pore structure and extremely large surface area and pore volume, have received much attention because of their biomedical application potential. Using MPS NPs for biomedical devices requires the verification of their biocompatibility because the surface area of NPs is one of the most important determinants of toxicity, including the cellular uptake and immune response. We have previously reported that the cytotoxicity and inflammation potential of MPS NPs have been shown to be lower than those of general amorphous colloidal silica (Col) NPs in macrophages, but the low cytotoxicity does not guarantee high biocompatibility in vivo. In this study, we compared the in vivo immunotoxicity of MPS and Col NPs in the mouse model to define the effects of pore structural conditions of silica NPs.Materials and methods: Both MPS and Col NPs (2, 20, and 50 mg/kg/day) were intraperitoneally administered in female BALB/c mice for 4 weeks, and clinical toxicity, lymphocyte population, serum IgG/IgM levels, and histological changes were examined.Results: There was no overt sign of clinical toxicity in either MPS- or Col-treated mice. However, MPS NPs led to significant increases in liver and spleen weight and splenocyte proliferation. Mice treated with MPS NPs showed altered lymphocyte populations (CD3+, CD45+, CD4+, and CD8+) in the spleen, increased serum IgG and IgM levels, and histological changes. Despite slight changes in lymphocyte populations in the spleen, Col NPs did not alter other immunological factors.Conclusion: The results indicate that in vivo exposure to MPS NPs caused more damage to systemic immunity than that of Col NPs through the dysregulation of the spleen. The results for in vivo data are inconsistent with those for in vitro data, which show low
Comparative Study of Various Preparation Methods of CuO–CeO2 Catalysts for Oxidation of n–Hexane and iso–Octane  [cached]
Ashutosh Mishra,B.D. Tripathi,A.K. Rai,Ram Prasad
Bulletin of Chemical Reaction Engineering & Catalysis , 2013, DOI: 10.9767/bcrec.7.3.4076.172-178
Abstract: The complete oxidation of n-Hexane and iso-Octane was studied individually in a fixed bed tubular flow reactor over CuO-CeO2 catalysts synthesized via four different methods namely urea-nitrate combustion method, urea gelation/co-precipitation method, citric acid sol-gel method and co-impregnation method. Laser diffraction was employed in catalysts characterization. The results obtained from the complete conversion of n-Hexane and iso-Octane revealed that the CuO-CeO2 catalysts prepared by urea-nitrate combustion method (UNC) showed the best performance than the catalysts prepared by other methods used in the present investigation. CuO-CeO2 catalysts prepared by UNC method achieve total n-Hexane and iso-Octane conversion to CO2 at lower temperatures of 280 0C and 340 0C respectively due to the larger surface area of the catalysts which increases the specific rate of reaction. 2013 BCREC UNDIP. All rights reserved Received: 30th October 2012; Revised: 30th November 2012; Accepted: 3rd December 2012 [How to Cite: A. Mishra, B.D. Tripathi, A.K. Rai, R. Prasad (2013). Comparative Study of Various Preparation Methods of CuO–CeO2 Catalysts for Oxidation of n–Hexane and iso–Octane. Bulletin of Chemical Reaction Engineering & Catalysis, 7(3): 172-178. (doi:10.9767/bcrec.7.3.4076.172-178)] [Permalink/DOI: http://dx.doi.org/10.9767/bcrec.7.3.4076.172-178]
Surface patterns in drying films of silica colloidal dispersions  [PDF]
Fran?ois Boulogne,Frédérique Giorgiutti-Dauphiné,Ludovic Pauchard
Physics , 2014, DOI: 10.1039/C4SM02106A
Abstract: We report an experimental study on the drying of silica colloidal dispersions. Here we focus on a surface instability occurring in a drying paste phase before crack formation which affects the final film quality. Observations at macroscopic and microscopic scales reveal the occurrence of the instability, and the morphology of the film surface. Furthermore, we show that the addition of adsorbing polymers on silica particles can be used to suppress the instability under particular conditions of molecular weight and concentration. We relate this suppression to the increase of the paste elastic modulus.
Preparation of silica with controlled pore sizes for enzyme immobilization
Trevisan, H.C.;Mei, L.H.I.;Zanin, G.M.;
Brazilian Journal of Chemical Engineering , 2000, DOI: 10.1590/S0104-66322000000100006
Abstract: a simple method for the preparation of silica with controlled pore size, for use as a support for the immobilization of enzymes, is described in this article. using sodium silicate and hydrochloric acid, a microporous silica was obtained that was then submitted to a hydrothermal treatment, resulting in macroporous silica suitable for enzyme immobilization. suitability of the macroporous silica as a support depends on the method chosen for its preparation, which will determine pore volume and the effect of hydrothermal treatment on pore size. the pore volume of the support was 0.8-0.9 cc/g and the average pore size, controlled by the hydrothermal treatment, was in the range of 16 to 75 nm. the enzyme amyloglucosidase was used for the immobilization studies.
Preparation of silica with controlled pore sizes for enzyme immobilization  [cached]
Trevisan H.C.,Mei L.H.I.,Zanin G.M.
Brazilian Journal of Chemical Engineering , 2000,
Abstract: A simple method for the preparation of silica with controlled pore size, for use as a support for the immobilization of enzymes, is described in this article. Using sodium silicate and hydrochloric acid, a microporous silica was obtained that was then submitted to a hydrothermal treatment, resulting in macroporous silica suitable for enzyme immobilization. Suitability of the macroporous silica as a support depends on the method chosen for its preparation, which will determine pore volume and the effect of hydrothermal treatment on pore size. The pore volume of the support was 0.8-0.9 cc/g and the average pore size, controlled by the hydrothermal treatment, was in the range of 16 to 75 nm. The enzyme amyloglucosidase was used for the immobilization studies.
Compact Layer of Alkali Ions at the Surface of Colloidal Silica  [PDF]
Aleksey M. Tikhonov
Physics , 2006, DOI: 10.1021/jp065538r
Abstract: The forces of electrical imaging strongly polarize the surface of colloidal silica. I used X-ray scattering to study the adsorbed 2-nm-thick compact layer of alkali ions at the surface of concentrated solutions of 5-nm, 7-nm, and 22-nm particles, stabilized either by NaOH or a mixture of NaOH and CsOH, with the total bulk concentration of alkali ions ranging from 0.1- to 0.7-mol/L. The observed structure of the compact layer is almost independent of the size of the particles and concentration of alkali base in the sol; it can be described by a two-layer model, i.e., an ~ 8 Angstrom thick layer of directly adsorbed hydrated alkali ions with a surface concentration 3x10(18) m(-2), and a ~ 13 Angstrom thick layer with a surface concentration of sodium ions 8x10(18) m(-2). In cesium-enriched sols, Cs+ ions preferentially adsorb in the first layer replacing Na+; their density in the second layer does not depend on the presence of cesium in the sol. The difference in the adsorption of Cs+ and Na+ ions can be explained by the ion-size-dependent term in the electrostatic Gibbs energy equation derived earlier by others. I also discuss the surface charge density and the value of surface tension at the sol's surface.
Synthesis and Characterization of Silica-supported Iron Nanocatalyst by Modified Colloidal Method  [PDF]
Nor Aziyan Mohd Nasir,Noor Asmawati Mohd Zabidi,Chong Fai Kait
Journal of Applied Sciences , 2011,
Abstract: Silica-supported iron nanocatalysts for Fischer-Tropsch Synthesis (FTS) were prepared using the modified colloidal method in the presence of surfactants in an organic medium. The iron loading on silica support was varied at 3, 5 and 6 wt.%. The samples were characterized by XPS, TPR and TEM. The presence of Fe2O3 on the silica support was confirmed by XPS. TPR analysis showed that the increase in Fe loading caused the first reduction temperature of the nanocatalysts to shift to a higher temperature. TEM analysis revealed that the iron nanoparticles were not uniformly distributed on the silica support. The size of iron nanoparticles ranged from 4 to 20 nm. For the 3 and 5 wt.% Fe/SiO2, the size of the iron nanoparticles were mostly in the range of 1-5 nm, whereas for the 6 wt%, most of the iron nanoparticles (74%) were in the range of 6-10 nm.
Float Glass Surface Preparation Methods for Improved Chromium Film Adhesive Bonding
Algirdas LAZAUSKAS,Viktoras GRIGALIūNAS
Materials Science , 2012, DOI: 10.5755/j01.ms.18.2.1924
Abstract: Contact angle measurements using method based on B-spline snakes (active contours) were applied to investigate surface wettability properties of commercial soda-lime-silica float glass subjected to various surface preparation methods. The comparative evaluation of vacuum evaporated chromium thin film adhesion strength to float glass treated under different surface preparation methods was performed using scratch tests. Also, the influence of float glass substrate heating for chromium thin film adhesion strength was investigated. Surface activation and contamination removal by O2 plasma process and RCA-1 surface preparation method revealed the best results, where surfaces were free of hydrophobic contaminants with low contact angles ranging from 4° to 8°. For majority of float glass surface preparation methods the contact angles were observed slightly higher for the “tin side” as compared with “air side”. Soda-lime-silica float glass surface wettability properties of both sides were equalized during bombardment in RIBE unit by Ar+ ion beam. O2 plasma process and RCA-1 surface preparation method for float glass resulted in a higher value of the thin chromium film adhesion to the float glass substrate as measured from the average critical normal force (O2 plasma 0.169 N; RCA-1 0.14 N) in scratch tests. The float glass substrate heating (100 °C) in the vacuum chamber before chromium thin film evaporation process resulted in even higher value of the thin chromium film adhesion to the float glass substrate. DOI: http://dx.doi.org/10.5755/j01.ms.18.2.1924
Preparation of colloidal gold immunochromatography strip for detection of methamidophos residue

SHI Chenggang,ZHAO Suqing,ZHANG Kun,HONG Guobao,ZHU Zhenyu,

环境科学学报(英文版) , 2008,
Abstract: Methamidophos (Met) is a broad spectrum organophosphorus insecticide and acaricide.Even a trace of its residue is harmful to humans and many animals.In this study,the synthesis and identification of colloidal gold particles and antibody-colloidal gold conjugates were performed,and the preparation of colloidal gold immunochromatography strip was conducted for detection of Met residue.The size of colloidal gold particles was checked using a transmission electron microscope (TEM).The formation of antibody-coll...
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