• Title/Summary/Keyword: cell permeability

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Optimization of Chitosan-Alginate Encapsulation Process Using Pig Hepatocytes or Development of Bioartificial Liver

  • LEE , JI-HYUN;LEE, DOO-HOON;SON, JEONG-HWA;PARK, JUNG-KEUG;KIM, SUNG-KOO
    • Journal of Microbiology and Biotechnology
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    • v.15 no.1
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    • pp.7-13
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    • 2005
  • Chitosan-alginate capsules were formed by electrostatic interactions and exhibited an appropriate mechanical strength, permeability, and stability for the culture of hepatocytes. Pig hepatocytes were isolated and hepatocyte spheroids formed and immobilized in chitosan-alginate capsules. An encapsulation procedure of 3 min and spheroid formation period of 24 h were the optimum conditions for the best liver functions. Pig hepatocytes with a cell density of $6.0{\tomes}10^6$ cells/ml in the capsules were found to be most suitable for application in a bioartificial liver support system. The encapsulated pig hepatocyte spheroids exhibited stable ammonia removal and urea secretion rates in a bioreactor for 2 weeks. Accordingly, chitosan-alginate encapsulated hepatocyte spheroids in a packed-bed bioreactor would appear to have potential as a bioartificial liver.

Development and Application of Biocompatible Polymers(II) ―Biocompatibility of Chitosan Graft Copolymer with Phosphoryl Choline groups― (생체적합성 고분자의 개발과 응용(II) ―Phosphoryl choline기를 가진 키토산 그래프트공중합체의 생체적합성―)

  • Lee, Mi Kyung;Park, Heung Sup;Kim, Eun Young;Park, Soo Min
    • Textile Coloration and Finishing
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    • v.7 no.2
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    • pp.63-69
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    • 1995
  • To improve the blood compatibility of chitosan membranes, 2-(methacryloyloxy)-ethyl-2-(trimethylammonium)ethyl phosphate(MTP), which is a methacrylate with phospholipid polar groups, was grafted on the surface of chitosan membranes and the biocompatibility of MTP-grafted chitosan membranes was investigated. The permeation coefficient gradually decreased with increasing in molecular weights of biocomponents below 10$^{4}$, and drastically decreased above 10$^{4}$. This result corresponds with the permeability of solutes in case of hemodialysis membranes. The MTP-grafted chitosan membranes displayed less blood cell adhesion than the chitosan membranes. This may due to the formation of biomembrane4ike surface by adsorption and arrangement of phospholipid molecules from serum onto the MTP copolymer surface.

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The Role of Mast Cells in Innate and Adaptive Immunity. (선천면역 및 적응면역에서 비만세포의 기능)

  • Kim, Young-Hee
    • Journal of Life Science
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    • v.18 no.6
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    • pp.891-896
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    • 2008
  • The function of mast cells as effector cells in allergy has been extensively studied. Mast cells activated through high affinity IgE-receptor ($Fc{\varepsilon}RI$) release diverse mediators, and lead to smooth muscle constriction, vasodilation, increase of vascular permeability, leukocyte recruitment and activation, mucus secretion, and tissue proliferation and remodeling. However, various other immunological and non-immunological signals can lead to the activation of mast cells. In resent years, mast cells have been identified to be involved in a complex range of immune functions. Mast cells can be important as key players in the regulation of innate as well as adapted immune responses, and may influence the development of allergy, autoimmune disorder and peripheral tolerance. This review summarizes the recent advances in the understanding of effector functions of mast cells in immune responses.

Changes in the composition according to the manufacturer and the characteristics of the ceramic support (조성변화에 따른 세라믹지지체의 제조 및 그 특성)

  • Kwom, Yongjin;Choi, Byunghyun;Jee, Mijung;Ahn, Yongtae;Seol, Kwanghee;Nham, Shan
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.83.2-83.2
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    • 2011
  • In this study, we fabricated tubular ceramic support for segmented-in-series solid oxide fuel cell (SOFC) by using MAO(MgAl-stabilized ) as main material and activated carbon as pore former. Thermal expansion properties of ceramic support with different amounts of activated carbon were analyzed by using dilatometer to decide a suitable sintering temperature. The tubular ceramic supports with different amounts of activated carbon (15, 20, 30wt.%) were fabricated by the extrusion technique. After sintering at $1400^{\circ}C$ for 2h, cross section and surface morphology of tubular ceramic support were analyzed by using SEM image. Also, the porosity, mechanical property, gas permeability of tubular ceramic supports was measured. Based on these results, we established the suitable fabrication technique of tubular ceramic support for segmented-in-series SOFC.

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Synthesis and Anti-HCV Activity of 3',5'-cyclic SATE Phosphonodiester Nucleoside as a Novel Prodrug

  • Liu, Lian Jin;Seo, Rac-Seok;Yoo, Seung-Won;Choi, Jin;Hong, Joon-Hee
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.915-920
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    • 2010
  • A novel 2',4'-dimethyl carbocyclic adenosine 5'-phosphonic acid analogue (20) was prepared using acyclic stereoselective route from commercially available 4-hydroxybutan-2-one (4). To improve cellular permeability and enhance the anti-HCV activity of this phosphonic acid, a 3',5'-cyclic SATE phosphonodiester nucleoside prodrug (22) was prepared. The synthesized phosphonic nucleoside analogues, (20) and (22), were assayed for their ability to inhibit HCV RNA replication in a subgenomic replicon Huh7 cell line.

Immunoregulative Action of Bangpoongtongsungsan (방풍통성산(方風通聖散) 전탕액(煎湯液)의 면역(免疫) 조절작용(調節作用))

  • Lee, Chang-kyu;Song, Jeong-mo
    • Journal of Sasang Constitutional Medicine
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    • v.10 no.2
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    • pp.589-613
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    • 1998
  • The purpose of this research was to investigate effects of Bangpoongtongsungsan water extract(BTSE) on the immune reaction, anti-allergy action and anti-inflammatory action in BALB/c mice. The administration of BTSE (500mg/kg) enhanced the cell viability of thymocytes and the population of helper T cells in splenic T-lymphocytes. BTSE suppressed the production of nitric oxide, but enhanced the phagocytic activity in peritoneal macrophages. BTSE enhanced hemagglutination titer in mice. BTSE inhibited passive cutaneous anaphylaxis induced by egg albumin in rat, the lethal anaphylaxis induced by platelet activating factor and compound 48/80 in mice, and then inhibited the degranulation of peritoneal mast cells induced by compound 48/80. BTSE did not inhibit Arthus reaction, but inhibited the delayed type hypersensitivity induced by SRBC and contact dermatitis induced by DNFB. BTSE inhibited the acute hind paw edema induced by histamine after 30 minutes, the permeability of evans blue into peritoneal cavity induced by acetic acid and the writhing syndrome induced by acetic acid. These results suggest that BTSE has an immunopotentiative action, anti-allergy action and anti-inflammatory action via the inhibition of histamine release.

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Inhibitory Effect of Mouse Paw Edema by Solanum melongena Aqueous Extract (노랑가지 물추출물에 의한 생쥐 발바닥 부종의 억제효과)

  • 김대기;백옥선;임종필;이영미
    • YAKHAK HOEJI
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    • v.47 no.5
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    • pp.325-330
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    • 2003
  • Solanum melongena L. (Solanaceae) has anti-oxidant, analgesic, and hypolipidemic effects. We previously showed that Solanum melongena (SM) aqueous extract inhibits mast cell-mediated allergic reactions. The activation of protease-activated receptor-2 (PAR-2) induces acute inflammation in rat hindpaw. In the present study, we investigated the effects of the SM aqueous extract on mouse paw edema induced by PAR2 agonists. Trypsin or trans-cinnamoyl-LIGRLO-NH$_2$ (tc-NH$_2$), PAR-2 agonists, was injected into the hind paw of mice to induce paw edema. SM aqueous extract (1, 5, 10, and 100 mg/kg) was orally administered 1 hr before induction of paw edema. SM aqueous extract (5, 10, and 100 mg/kg) significantly inhibited both paw edema and vascular permeability in the dose-dependent manner. Furthermore, SM aqueous extract (10 mg/kg) significantly inhibited PAR-2 agonist-induced myeloperoxidase (MPO) activity and tumor necrosis factor (TNF)-$\alpha$ expression in paw tissue compared to that of saline. These results suggest that SM aqueous extract may be useful for treatment of PAR-2-mediated inflammation.

Transdermal Permeation of Riboflavin in Ointment Bases Using Gums & Enhancers (Gum류의 연고제제와 흡수촉진제가 Riboflavin의 경피흡수에 미치는 영향)

  • 오세영;황성규;김판기
    • Journal of Environmental Health Sciences
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    • v.26 no.2
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    • pp.91-96
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    • 2000
  • We investigated characters of transdermal therapeutic system(TTS) and the skin permeability of that with applying drug delivery system(DDS). Natural gums were selected as material of TTS. The permeation of natural gums ointment containing drug in rat skin using diffusion cell model. Permeation properties of materials were investigated for water soluble drug such as riboflavin in vitro. We used glycerin, PEG 600 and oleic acid as enhancers. Since dermis has more hydration than the stratum corneum, skin permeation rate at steady state was highly influenced when glycerin was used in riboflavin. The permeation rate of content enhancer and drug was found to be faster than that of content riboflavin only. These results showed that skin permeation rate of drug across the composite was mainly dependent on the property of ointment base and drug. All the gum ointment tested showed good safety. Proper selection of the materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate.

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Effects of BuOH Extract of the Root of Aralia elata as an Absorption Enhancer on the Transport of Chondroitin Sulfate and Its Digestion Products In Vitro and In Vivo

  • Sim, Joon-Soo;Li, Da-Wei;Cho, Hai-Lim;Cho, So-Yean;Jeong, Choon-Sik;Lee, Eun-Bang;Kim, Yeong-Shik
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.415.2-415.2
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    • 2002
  • We investigated the absorption enhancing effect of BuOH extract of the root of Aralia elata (BERAE) in Caco-2 cell monolayers and rats. At the concentration of both 0.04% and 0.08% (w/v). BERAE decreased the transepithelial electrical resistance (TEER) values and increased the permeability of intact chondroitin sulfate (CS) and its digestion products as hydrophilic macromolecules in a dose dependent manner. We also evaluated the cytotoxicity of BERAE for the determination of a proper concentration as an absorption enhancer. (omitted)

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A Study on Corrosion Potential of Cracked Concrete Beam According to Corrosion Resistance Assessment (부식 저항성 평가에 따른 균열 콘크리트 보의 부식전위 연구)

  • Song, Ha-Won;Lee, Chang-Hong;Lee, Kewn-Chu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.1 s.53
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    • pp.97-105
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    • 2009
  • Development and use of blended cement concrete is gaining more importance in the construction industry with reference to durability mainly due to the pore refinement and reduction in permeability. Cracks play a major role on important parameters like permeability, rate of chloride ingress, compressive strength and thus affect the reinforcement corrosion protection. Furthermore, when a crack occurs in the cover concrete, the corrosion of the steel reinforcement may be accelerated because the deterioration causing factors can pass through the crack. In recent years the effect of cracking on the penetration of concrete has been the subject of numerous investigations. Therefore assessing the service life using blended concrete becomes obviously in considering the durability. In the present study, the corrosion assessment of composite concrete beams with and without crack with of 0.3mm using OPC, 30% PFA, 60% GGBS, 10% SF was performed using half cell potential measurement, galvanic potential measurement, mass loss of steel over a period of 60days under marine environmental conditions and the results were discussed in detail.