• Title/Summary/Keyword: nanodispersion

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Lipid nanodispersion for parenteral drug delivery: in vitro characterization

  • Lee, Jung-Min;Choi, Sung-Up;Lee, Byoung-Moo;Lee, Sung-Jae;Choi, Young-Wook
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.295.2-295.2
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    • 2003
  • Lipid nanodispersion (LN) composed of biocompatible lipids and surfactants is an alternative parenteral drug delivery system especially for lipophilic drugs. It has been studied for versatile applications such as oral, parenteral, topical, ocular, vaccine, and peptide drug delivery. The purpose of this study was to produce a novel LN system for intravenous injection using the high pressure homogenization. (omitted)

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Effect of Cubic Liquid Crystalline Systems on Skin Localization of Oregonin and Hirsutanonol

  • Im, Tae-Jong;Kang, Myung-Joo;Seo, Dong-Woo;Lee, Jae-Hwi
    • Biomolecules & Therapeutics
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    • v.16 no.3
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    • pp.226-230
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    • 2008
  • Monoolein-based cubic liquid crystalline systems were formulated for the local delivery of oregonin and hirsutanonol for the treatment of atopic dermatitis. The liquid crystalline phase and its nanodispersion containing drugs were prepared. The skin permeation and deposition properties of the drugs were examined in normal and delipidized rat skin. The proportion of oregonin (%) deposited in normal skin after topical administration of the drugs in the form of aqueous solution, cubic phase or cubic nanodispersions were $1.53\;{\pm}\;0.46$, $3.62\;{\pm}\;0.17$ and $5.13\;{\pm}\;0.73$, and those of hirsutanonol were $2.46\;{\pm}\;0.02$, $5.44\;{\pm}\;0.27$ and $17.28\;{\pm}\;2.19$, respectively. The greater lipophilicity and thus greater skin affinity of hirsutanonol than oregonin contributed the greater amount of skin deposition. The monoolein-based liquid crystalline phases significantly increased the amount of both drugs permeated and deposited. Approximately 3.2, 2.1 and 3.0 times greater amount of oregonin, and 3.4, 2.1 and 2.2 times greater amount of hirsutanonol were deposited in delipidized skin after administration of each drug in the form of aqueous solution, cubic phase and cubic nanodispersions system, respectively, because of lowered barrier function of the delipidized skin. In this study, the effects of drug property, vehicles type and skin condition on skin deposition and permeation properties of drug were examined and concluded that monoolein-based liquid crystalline systems would be a promising formulation for the local delivery of drugs.

Multifunctionality in Ceramic/Metal Nanocomposites

  • Sekino, Tohru;Kondo, Hiroki;Niihara, Koichi
    • Journal of Powder Materials
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    • v.8 no.3
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    • pp.186-191
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    • 2001
  • Several fabrication processes, corresponding nanostructural features and multifunctionality as well has been investigated for oxide ceramic based nanocomposites with metal nanodispersion (i.e., ceramic/metal nanocomposites). Transition metal (Ni, Co, etc) dispersed alumina and zirconia based nanocomposites have been synthesized by reducing and hot-press sintering of ceramic and metal oxide mixtures prepared by several method. Improved fracture strength (1.1 and 1.9 GPa for $Al_2O_3/Ni$ and $ZrO_2/Ni$ nanocomposites, respectively) of these composites have been achieved according to their nanostructures. In addition, ferromagnetic characteristic has been kept. The variation of magnetization with an applied stress has found to be more sensitive as smaller as the magnetic metal dispersion is. This result thus suggests the possibility of fracture and/or stress sensing of the composites by simple magnetic measurement.

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Pharmacokinetic behavior of lipid nanodispersion system for parenteral delivery of paclitaxel in rats

  • Choi, Sung-Up;Lee, Jung-Min;Lee, Byoung-Moo;Choi, Young -Wook
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.225.1-225.1
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    • 2003
  • Purpose. Paclitaxel has demonstrated significant activity in clinical trials against a wide variety of tumors. The clinical application of Taxol$\^$\ulcorner/, a commercial product of solubilized paclitaxel with co solvents of ethanol and Cremophor, however, has been limited largely by hypersensitivity of the excipient. The aim of this study was to formulate paclitaxel-loaded lipid nanodispersions (Px-LN) for i.v. administration without toxic excipients, and to evaluate in vitro characteristics and in vivo pharmacokinetic behaviors. (omitted)

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Fabrication of transparent conducting films of carbon nanotubes using a spray method

  • Geng, Hong Zhang;Lee, Kyu;Song, Young-Il;Kim, Gil-Yong;Choi, Ha-Kyu;Jun, Bae-Jung;Ahn, Kay-Hyeok;Lee, Young-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.525-528
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    • 2006
  • Transparent conducting films were fabricated on polyethylene terephthalate substrate by a spray method using double-walled carbon nanotubes dispersed in organic solvent and water-based solution. We analyzed the films by absorption spectra, sheet resistance, and scanning electron microscopy. Transparent conducting films with high uniformity and high transparency were fabricated by the spray method. We found that the dispersion particularly nanodispersion of CNTs was of crucial importance to improve the film performance.

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Immune-Enhancing Effect of Nanometric Lactobacillus plantarum nF1 (nLp-nF1) in a Mouse Model of Cyclophosphamide-Induced Immunosuppression

  • Choi, Dae-Woon;Jung, Sun Young;Kang, Jisu;Nam, Young-Do;Lim, Seong-Il;Kim, Ki Tae;Shin, Hee Soon
    • Journal of Microbiology and Biotechnology
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    • v.28 no.2
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    • pp.218-226
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    • 2018
  • Nanometric Lactobacillus plantarum nF1 (nLp-nF1) is a biogenics consisting of dead L. plantarum cells pretreated with heat and a nanodispersion process. In this study, we investigated the immune-enhancing effects of nLp-nF1 in vivo and in vitro. To evaluate the immunostimulatory effects of nLp-nF1, mice immunosuppressed by cyclophosphamide (CPP) treatment were administered with nLp-nF1. As expected, CPP restricted the immune response of mice, whereas oral administration of nLp-nF1 significantly increased the total IgG in the serum, and cytokine production (interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-${\alpha}$)) in bone marrow cells. Furthermore, nLp-nF1 enhanced the production of splenic cytokines such as IL-12, TNF-${\alpha}$, and interferon gamma (IFN-${\gamma}$). In vitro, nLp-nF1 stimulated the immune response by enhancing the production of cytokines such as IL-12, TNF-${\alpha}$, and IFN-${\gamma}$. Moreover, nLp-nF1 given a food additive enhanced the immune responses when combined with various food materials in vitro. These results suggest that nLp-nF1 could be used to strengthen the immune system and recover normal immunity in people with a weak immune system, such as children, the elderly, and patients.

Nanodispersion-Strengthened Metallic Materials

  • Weissgaerber, Thomas;Sauer, Christa;Kieback, Bernd
    • Journal of Powder Materials
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    • v.9 no.6
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    • pp.441-448
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    • 2002
  • Dispersions of non-soluble ceramic particles in a metallic matrix can enhance the strength and heat resistance of materials. With the advent of mechanical alloying it became possible to put the theoretical concept into practice by incorporating very fine particles in a flirty uniform distribution into often oxidation- and corrosion- resistant metal matrices. e.g. superalloys. The present paper will give an overview about the mechanical alloying technique as a dry, high energy ball milling process for producing composite metal powders with a fine controlled microstructure. The common way is milling of a mixture of metallic and nonmetallic powders (e.g. oxides. carbides, nitrides, borides) in a high energy ball mill. The heavy mechanical deformation during milling causes also fracture of the ceramic particles to be distributed homogeneously by further milling. The mechanisms of the process are described. To obtain a homogeneous distribution of nano-sized dispersoids in a more ductile matrix (e.g. aluminium-or copper based alloys) a reaction milling is suitable. Dispersoid can be formed in a solid state reaction by introducing materials that react with the matrix either during milling or during a subsequent heat treatment. The pre-conditions for obtaining high quality materials, which require a homogeneous distribution of small dis-persoids, are: milling behaviour of the ductile phase (Al, Cu) will be improved by the additives (e.g. graphite), homogeneous introduction of the additives into the granules is possible and the additive reacts with the matrix or an alloying element to form hard particles that are inert with respect to the matrix also at elevated temperatures. The mechanism of the in-situ formation of dispersoids is described using copper-based alloys as an example. A comparison between the in-situ formation of dispersoids (TiC) in the copper matrix and the milling of Cu-TiC mixtures is given with respect to the microstructure and properties, obtained.

Thermoelectric Properties of the n-type Bi2(Te0.9Se0.1)3 Processed by Hot Pressing with Dispersion of 0.5 vol% TiO2 Nanopowders (0.5 vol% TiO2 나노분말을 분산시킨 n형 Bi2(Te0.9Se0.1)3 가압소결체의 열전특성)

  • Park, D.H.;Oh, T.S.
    • Journal of the Microelectronics and Packaging Society
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    • v.20 no.1
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    • pp.15-19
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    • 2013
  • The n-type $Bi_2(Te_{0.9}Se_{0.1})_3$ powders, which were fabricated by melting/grinding method and dispersed with 0.5 vol% $TiO_2$ nanopowders, were hot-pressed in order to investigate the effects of $TiO_2$ dispersion on the thermoelectric properties of the hot-pressed $Bi_2(Te_{0.9}Se_{0.1})_3$. Excellent thermoelectric properties such as a maximum figure-of-merit of $2.93{\times}10^{-3}/K$ and a maximum dimensionless figure-of-merit of 1.02 were obtained for the hot-pressed $Bi_2(Te_{0.9}Se_{0.1})_3$. With dispersion of 0.5 vol% $TiO_2$ nanopowders, the maximum figure-of-merit and the maximum dimensionless figure-of-merit decreased to $2.09{\times}10^{-3}/K$ and 0.68, respectively.