• Title/Summary/Keyword: hepatocyte spheroid

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Morphologic Changes in Microcystin-LR Treated Hepatocytes In vitro

  • Rhee, Seong-Hee;Kim, Bum-Seok;Lim, Chae-Woong
    • Toxicological Research
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    • v.22 no.3
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    • pp.301-306
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    • 2006
  • Microcystin-LR(MC-LR), a cyanobacterial toxin produced by Microcystis aeruginosa, causes severe hepatotoxicity. Here we investigated the morphologic changes of rat hepatocyte spheroid induced by exposure of MC-LR($10^{-6}M$) in vitro. In addition, to determine the effects of such toxin in the process of hepatocyte spheroid formation, primarily isolated hepatocytes were incubated with MC-LR and the process of spheroid formation was observed. In both hepatocyte spheroid and suspension culture systems, the morphologic changes caused by MC-LR were noticible at 5 min post exposure and were characterized by the loss of microvilli, cytoplasmic vacuolation, the accumulation of lipid droplets, and blob formation. Especially, the size and numbers of blob on the cell surface were increased as the incubation time prolonged and the appearance of electron dense bodies were observed in the cytoplasm of hepatocyte at 20 min post exposure. Furthermore, bile canaliculi-like structures in the hepatocyte spheroids were slightly widened and the process of spheroids formation was inhibited in the isolated hepatocytes incubated with MC-LR. These results indicate that morphologic changes in. the hepatocyte membrane and organelles seem to be typical events in showing the MC-LR induced hepatotoxic effects and the spheroid culture method might be a useful experimental tool to evaluate hepatoxicity since it reflects the in vivo status of hepatocytes.

Effect of cell morphology on the hepatic functions adult rat hepatocytes (세포형태에 따른 쥐 간세포의 분화기능)

  • 이재호;박정극최태부
    • KSBB Journal
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    • v.7 no.4
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    • pp.278-283
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    • 1992
  • Rat hepatocytes were isolated and cultured on the petri dishes treated with various coating materials. Untreated or collagen coated petri dish gave monolayer culture of hepatocyte and proteoglycan, dermatan sulfate, and BSA treated petri dish gave hemispheroid. The untreated Primaria petri dish gave spheroid type of hepatocyte, and heparin and hyaluronic acid treatment gave multilayers. To sustain high cell viability, monolayer cultured hepatocytes was more useful, while it was found that the hemispheroid or spheroid type hepatocytes was more active in the hepatic functions such as ammonia metabolism and albumin synthesis.

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APPLICATION OF THREE DIMENSIONAL CULTURE OF ADULT RAT HAPATOCYTES IN POLYURETHANE FOAM PORES FOR AN ARTIFICIAL LIVER SUPPORT SYSTEM

  • Funatsu, K.;Matsushita, T.;Ijima, H.;Iwahashi, T.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.137-144
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    • 1994
  • Spherical multicellular aggregates of adult rat hepatocytes (spheroid) which have tissue like structure, were formed and immobilized in the pores of polyurethane foam (PUF) which was used as a culture substratum. These hepatocyte/spheroids, about 100 $\mu\textrm{m}$ in diameter, have maintained higher differentiated functions than those of hepatocyte/monolayer for about 3 weeks in serum-free medium. Then, we designed a prototype module of an artificial liver support system using a PUF/spheroid packed-bed, in which hepatocyte/spheroids were immobilized at high density. The urea synthesis activity of the artificial liver was maintained at least 10 days in 100% rat blood plasma. We start examining the performance of hybrid artificial liver in an ex vivo extracorporeal experiment with an acute hepatic failure rat.

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Human adipose-derived mesenchymal stem cell spheroids improve recovery in a mouse model of elastase-induced emphysema

  • Cho, Ryeon Jin;Kim, You-Sun;Kim, Ji-Young;Oh, Yeon-Mok
    • BMB Reports
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    • v.50 no.2
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    • pp.79-84
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    • 2017
  • Emphysema, a pathologic component of the chronic obstructive pulmonary disease, causes irreversible destruction of lung. Many researchers have reported that mesenchymal stem cells can regenerate lung tissue after emphysema. We evaluated if spheroid human adipose-derived mesenchymal stem cells (ASCs) showed greater regenerative effects than dissociated ASCs in mice with elastase-induced emphysema. ASCs were administered via an intrapleural route. Mice injected with spheroid ASCs showed improved regeneration of lung tissues, increased expression of growth factors such as fibroblast growth factor-2 (FGF2) and hepatocyte growth factor (HGF), and a reduction in proteases with an induction of protease inhibitors when compared with mice injected with dissociated ASCs. Our findings indicate that spheroid ASCs show better regeneration of lung tissues than dissociated ACSs in mice with elastase-induced emphysema.

Effects od Segree of Cell-Cell Contact on Liver Specific Function of Rat Primary Hepatocytes

  • Tang, Sung-Mun;Lee, Doo-Hoon;Park, Jung-Keug
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.2
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    • pp.99-105
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    • 2000
  • Cell-Cell interaction and the extracellular matrix (ECM) are belisved to play essential roles during in vitro culturing of primary hepatocytes in the control of differentiation and in the maintenance of tissue spcific functions. The objective of this study was to examine the effects of degree of cell-cell contact (DCC) on liver sperific function of rat promary hepatocytes. Hepatocyte aggregates with various with various degrees of cell-cell contantact, I. e., dispersed cell, longish aggregate, rugged aggregate, and smooth spheroid were obtained at 1, 5-6, 15-20, and 36-48 hrs, respectively in suspension cultures grown in spinner flasks embedded in Caalginate bead and collagen gel in order. The may result from mass transfer limitation and shear damage caused by agitation during aggregation. The rugged aggregate showed a higer viability and albumin secretion rate than the dispersed cells or the other aggregates. This result indicates the possible enhancement of a bioartificial liver's (BAL) performance using primary hepatocytes and the reduction in time to prepare a BAL through optimization of the immobilization time.

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Development of Hepatocyte Spheroids Immobilization Technique Using Alternative Encapsulation Method

  • Kim, Sungd-Po;Lee, Doo-Hoon;Park, Jung-Keug
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.3 no.2
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    • pp.96-102
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    • 1998
  • Primary hepatocytes of small animals such as rat and rabbit were often used for the study of extracorporeal liver support systems. Freshly isolated rat hepatocytes form spheroids within tow days when cultivated as suspension in spinner vessels. These spheroids showed enhanced liver specific functions and more differentiated morphology compared to hepatocytes cultured as monolayers However, shear stress caused by continuous agitation deteriorated spheroids gradually. In this work we immobilized spheroids to prolong liver specific activities. First, hepatocyte spheroids were suspended in collagen solution containing calcium chloride and then dropped into alginate solution. A thin layer of calcium alginate was formed around the droplet and then was removed after the inner collagen was gelled by treatment of sodium citrate buffer. Spheroids embedded in collagen-gel bead maintained liver specific functions such as albumin secretion rate longer than hepatocyte spheroids exposed to shear stress. Therefore, we suggest that this immobilization technique may offer an effective long-term hepatocyte cultivation and facilitase the development of a bioartificial liver support device.

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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.

Determination of Optimum Aggregates of Porcine Hepatocytes As a Cell Source of a Bioartificial Liver

  • Lee, Doo-Hoon;Lee, Ji-Hyun;Choi, Jeong-Eun;Kim, Young-Jin;Kim, Sung-Koo;Park, Jung-Keug
    • Journal of Microbiology and Biotechnology
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    • v.12 no.5
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    • pp.735-739
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    • 2002
  • Large quantities of porcine hepatocyte aggregates with various degrees of aggregation (DA) could be obtained by controlling the suspension periods (0,9,24, and 48 h), and by entrapping the hepatocyte aggregates in model materials of encapsulation such as Ca-alginate and type-I collagen gels. The effects of DA on liver-specific functions of hepatocytes were evaluated in order to obtain optimum DA for the cell source of bioartificial liver (BAL) systems. Irregular rugged aggregates (size $75 \pm 28$ $\mu\textrm{m}$) farmed by 24 h of suspension culturing showed peak viability and hepatic functions such as ammonia removal and albumin secretion in the two types of entrapment systems, thus offering themselves as a stable cell source of a BAL system for hepatic functions and scale-up.

Formation of Spheroids of Adult Rat Primary Hepatocytes in Polyurethane Foam (폴리우레탄 폼을 이용한 쥐 일차 간세포의 구상체 배양)

  • 안재일;이두훈
    • Journal of Biomedical Engineering Research
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    • v.19 no.3
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    • pp.215-224
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    • 1998
  • This paper is fundamental study to develope the extracorporeal liver support system for patient with fulminant hepatic failure(FHF) or being expected for orthotopic liver transplantation. The polyurethane foam, which is composed of the density of 33kg/m3, the average pore diameter of 500${\mu}{\textrm}{m}$, the closed window of 60-70%, was manufactured with the prepolymer of 15% NCO-, Hepatocytes were inoculated to form spheroids in polyurethane foam. The time of spheroid formation in BSA(Bovine Serum Albumin) coated polyurethane foam was shorter than that in raw polyurethane foam. To verify the function of hepatocyte spheroids, we measured ammonia removal rate, urea and albumin secretion rate. Polyurethane foam was suitable for culture of hepatocyte spheroids. And culture of hepatocyte spheroids in polyurethane foam has high possibility in using as an extracorporeal liver support system.

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Long-Duration Three-Dimensional Spheroid Culture Promotes Angiogenic Activities of Adipose-Derived Mesenchymal Stem Cells

  • Lee, Jun Hee;Han, Yong-Seok;Lee, Sang Hun
    • Biomolecules & Therapeutics
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    • v.24 no.3
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    • pp.260-267
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    • 2016
  • Mesenchymal stem cells (MSCs) offer significant therapeutic promise for various regenerative therapies. However, MSC-based therapy for injury exhibits low efficacy due to the pathological environment in target tissues and the differences between in vitro and in vivo conditions. To address this issue, we developed adipose-derived MSC spheroids as a novel delivery method to preserve the stem cell microenvironment. MSC spheroids were generated by suspension culture for 3 days, and their sizes increased in a time-dependent manner. After re-attachment of MSC spheroids to the plastic dish, their adhesion capacity and morphology were not altered. MSC spheroids showed enhanced production of hypoxia-induced angiogenic cytokines such as vascular endothelial growth factor (VEGF), stromal cell derived factor (SDF), and hepatocyte growth factor (HGF). In addition, spheroid culture promoted the preservation of extracellular matrix (ECM) components, such as laminin and fibronectin, in a culture time- and spheroid size-dependent manner. Furthermore, phosphorylation of AKT, a cell survival signal, was significantly higher and the expression of pro-apoptotic molecules, poly (ADP ribose) polymerase-1 (PARP-1) and cleaved caspase-3, was markedly lower in the spheroids than in MSCs in monolayers. In the murine hindlimb ischemia model, transplanted MSC spheroids showed better proliferation than MSCs in monolayer. These findings suggest that MSC spheroids promote MSC bioactivities via secretion of angiogenic cytokines, preservation of ECM components, and regulation of apoptotic signals. Therefore, MSC spheroid-based cell therapy may serve as a simple and effective strategy for regenerative medicine.