The Experts below are selected from a list of 6198 Experts worldwide ranked by ideXlab platform
Kazumori Funatsu - One of the best experts on this subject based on the ideXlab platform.
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evaluation of a hybrid Artificial Liver module with Liver lobule like structure in rats with Liver failure
International Journal of Artificial Organs, 2008Co-Authors: K. Aoki, Kazumori Funatsu, Hiroshi Mizumoto, K Nakazawa, Toshihisa KajiwaraAbstract:We studied the recovery of rats with fulminant hepatic failure (FHF) by treating them with our original hybrid Artificial Liver support system (HALSS). We developed an original Artificial Liver module having a Liver lobule-like structure (LLS). This module consists of many hollow fibers regularly arranged in close proximity and hepatocyte aggregates (organoids) induced into the extra capillary space of the module by centrifugal force. The LLS module can express some Liver specific functions at high levels and maintain them for several months in vitro. In this study, we evaluated the efficacy of our LLS-HALSS by using rats with FHF induced by a method that combined partial hepatectomy with hepatic ischemia. In the animal experiments, blood ammonia levels rapidly increased in the control group (sham-HALSS group). These rats died during or immediately after application of the sham-HALLS. On the other hand, in the LLS module application group (LLS-control group), the increase in blood ammonia was completely suppressed and all rats recovered. Blood constituents at 4 weeks after application were at normal levels, and the weight of the Liver was the same as that of a normal rat. These results indicate that HALSS may be useful for treating Liver failure patients until Liver transplantation can be performed or until regeneration of the native Liver occurs.
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line hep g2 a possible cell source for hybrid Artificial Liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, Kazuhisa Ishihara, Hiroshi Mizumoto, K Okamura, Hiroyuki Ijima, Toshihisa Kajiwara, Kohji Nakazawa, Kazumori FunatsuAbstract:The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid Artificial Liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase—a urea cycle enzyme—was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volum...
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hepatocyte organoid culture in elliptic hollow fibers to develop a hybrid Artificial Liver
International Journal of Artificial Organs, 2004Co-Authors: Junji Fukuda, Hiroshi Mizumoto, Toshihisa Kajiwara, Kohji Nakazawa, Kazumori FunatsuAbstract:A novel organoid culture was developed in which hepatocytes maintain high Liver functions for more than several weeks in vitro. The main disadvantage of tissue-engineered organoids is the lack of a blood vessel structure between the aggregated cells. Because of depletion of oxygen, the thickness from the surface of an organoid at which hepatocytes can survive is limited. This study showed that a rat hepatocyte organoid that forms by using centrifugal force in a hollow fiber (HF) had a survival limit thickness of about 80 - 100 microm from the surface of the organoid. Based on the value, we designed an elliptic HF having less than 150 microm minor diameter by using a simple annealing method. All hepatocytes were supplied with oxygen and formed an organoid without a dead cell layer in this HF A hepatocyte organoid in an elliptic HF maintained ammonia removal activity twice as high as in the original HF for at least one month during culture. Albumin secretion activity of an organoid in an elliptic HF was also maintained for at least one month and was the same level as that of Liver in a living body. In conclusion, organoid culture by using an elliptic HF seems to be a promising technique to develop a hybrid Artificial Liver.
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We investigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We invesigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100-200 microm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, probably because they were cultured in a serum-free medium. In the PUF module in a circulation culture, HH had high ammonia removal and low synthesis activities similar to stationary culture. Hep G2 proliferated to a high cell density, such as about 4.8 x 10(7) cells/cm3-module at 10 days of culture. Although Hep G2 spheroids had low ammonia removal activity in each cell, the removal rate in the PUF module was almost the same as for PH at 7 days of culture because of the high cell density culture by cell proliferation. The albumin secretion rate by Hep G2 in the PUF module also increased with cell proliferation and was about 10 times higher than the initial for the rate for PH at 7 days of culture. These results suggest that Hep G2 is a potential cell source PUF-HALSS.
Hiroyuki Ijima - One of the best experts on this subject based on the ideXlab platform.
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line hep g2 a possible cell source for hybrid Artificial Liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, Kazuhisa Ishihara, Hiroshi Mizumoto, K Okamura, Hiroyuki Ijima, Toshihisa Kajiwara, Kohji Nakazawa, Kazumori FunatsuAbstract:The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid Artificial Liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase—a urea cycle enzyme—was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volum...
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line hep g2 a possible cell source for hybrid Artificial Liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, Kazuhisa Ishihara, Hiroshi Mizumoto, K Okamura, Hiroyuki Ijima, Toshihisa Kajiwara, Kohji Nakazawa, Kanimori FunatsuAbstract:The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid Artificial Liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase--a urea cycle enzyme--was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volume of the module) of Hep G2 spheroids treated with 5 mM SB were almost the same as those of primary porcine hepatocyte spheroids. These results suggest that simultaneous use of spheroid formation and SB treatment in Hep G2 is beneficial in enhancing the functions of human hepatocytes with potential applications in regenerative medicine and drug screening.
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We investigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We invesigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100-200 microm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, probably because they were cultured in a serum-free medium. In the PUF module in a circulation culture, HH had high ammonia removal and low synthesis activities similar to stationary culture. Hep G2 proliferated to a high cell density, such as about 4.8 x 10(7) cells/cm3-module at 10 days of culture. Although Hep G2 spheroids had low ammonia removal activity in each cell, the removal rate in the PUF module was almost the same as for PH at 7 days of culture because of the high cell density culture by cell proliferation. The albumin secretion rate by Hep G2 in the PUF module also increased with cell proliferation and was about 10 times higher than the initial for the rate for PH at 7 days of culture. These results suggest that Hep G2 is a potential cell source PUF-HALSS.
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hybrid Artificial Liver using hepatocyte organoid culture
Artificial Organs, 2001Co-Authors: Kazumori Funatsu, Mitsuo Shimada, Hiroyuki Ijima, Kohji Nakazawa, Yoichi Yamashita, Keizo SugimachiAbstract:We developed 2 types of hybrid Artificial Liver modules using hepatocyte organoid culture. One was a polyurethane foam (PUF)/hepatocyte spheroid packed-bed module. Hepatocytes spontaneously formed spheroids in the PUF pores, and they maintained Liver-specific functions well for at least 2 weeks in vitro. As a preclinical experiment, a hybrid Artificial Liver with 200 g porcine hepatocytes was applied to a pig (25 kg) with Liver failure and showed that the hybrid Artificial Liver was effective in support of Liver functions and stabilization of general conditions. We established a new technique of hepatocyte organoid formation using centrifugal force. A hepatocyte organoid formed by centrifugation in hollow fibers maintained functions for more than 4 months in vitro. We developed a new sinusoid-like structure module having hollow fibers arranged by spacers in a micro-regular arrangement. Inoculated hepatocytes in the extra-fiber space of the module formed the organoid by centrifugation, and they maintained the functions for at least 1 month in vitro. The results indicated that this module seems to be promising as a hybrid Artificial Liver.
Junji Fukuda - One of the best experts on this subject based on the ideXlab platform.
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line hep g2 a possible cell source for hybrid Artificial Liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, Kazuhisa Ishihara, Hiroshi Mizumoto, K Okamura, Hiroyuki Ijima, Toshihisa Kajiwara, Kohji Nakazawa, Kazumori FunatsuAbstract:The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid Artificial Liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase—a urea cycle enzyme—was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volum...
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line hep g2 a possible cell source for hybrid Artificial Liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, Kazuhisa Ishihara, Hiroshi Mizumoto, K Okamura, Hiroyuki Ijima, Toshihisa Kajiwara, Kohji Nakazawa, Kanimori FunatsuAbstract:The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid Artificial Liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase--a urea cycle enzyme--was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volume of the module) of Hep G2 spheroids treated with 5 mM SB were almost the same as those of primary porcine hepatocyte spheroids. These results suggest that simultaneous use of spheroid formation and SB treatment in Hep G2 is beneficial in enhancing the functions of human hepatocytes with potential applications in regenerative medicine and drug screening.
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hepatocyte organoid culture in elliptic hollow fibers to develop a hybrid Artificial Liver
International Journal of Artificial Organs, 2004Co-Authors: Junji Fukuda, Hiroshi Mizumoto, Toshihisa Kajiwara, Kohji Nakazawa, Kazumori FunatsuAbstract:A novel organoid culture was developed in which hepatocytes maintain high Liver functions for more than several weeks in vitro. The main disadvantage of tissue-engineered organoids is the lack of a blood vessel structure between the aggregated cells. Because of depletion of oxygen, the thickness from the surface of an organoid at which hepatocytes can survive is limited. This study showed that a rat hepatocyte organoid that forms by using centrifugal force in a hollow fiber (HF) had a survival limit thickness of about 80 - 100 microm from the surface of the organoid. Based on the value, we designed an elliptic HF having less than 150 microm minor diameter by using a simple annealing method. All hepatocytes were supplied with oxygen and formed an organoid without a dead cell layer in this HF A hepatocyte organoid in an elliptic HF maintained ammonia removal activity twice as high as in the original HF for at least one month during culture. Albumin secretion activity of an organoid in an elliptic HF was also maintained for at least one month and was the same level as that of Liver in a living body. In conclusion, organoid culture by using an elliptic HF seems to be a promising technique to develop a hybrid Artificial Liver.
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We investigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We invesigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100-200 microm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, probably because they were cultured in a serum-free medium. In the PUF module in a circulation culture, HH had high ammonia removal and low synthesis activities similar to stationary culture. Hep G2 proliferated to a high cell density, such as about 4.8 x 10(7) cells/cm3-module at 10 days of culture. Although Hep G2 spheroids had low ammonia removal activity in each cell, the removal rate in the PUF module was almost the same as for PH at 7 days of culture because of the high cell density culture by cell proliferation. The albumin secretion rate by Hep G2 in the PUF module also increased with cell proliferation and was about 10 times higher than the initial for the rate for PH at 7 days of culture. These results suggest that Hep G2 is a potential cell source PUF-HALSS.
Kohji Nakazawa - One of the best experts on this subject based on the ideXlab platform.
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line hep g2 a possible cell source for hybrid Artificial Liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, Kazuhisa Ishihara, Hiroshi Mizumoto, K Okamura, Hiroyuki Ijima, Toshihisa Kajiwara, Kohji Nakazawa, Kazumori FunatsuAbstract:The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid Artificial Liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase—a urea cycle enzyme—was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volum...
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line hep g2 a possible cell source for hybrid Artificial Liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, Kazuhisa Ishihara, Hiroshi Mizumoto, K Okamura, Hiroyuki Ijima, Toshihisa Kajiwara, Kohji Nakazawa, Kanimori FunatsuAbstract:The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid Artificial Liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase--a urea cycle enzyme--was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volume of the module) of Hep G2 spheroids treated with 5 mM SB were almost the same as those of primary porcine hepatocyte spheroids. These results suggest that simultaneous use of spheroid formation and SB treatment in Hep G2 is beneficial in enhancing the functions of human hepatocytes with potential applications in regenerative medicine and drug screening.
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hepatocyte organoid culture in elliptic hollow fibers to develop a hybrid Artificial Liver
International Journal of Artificial Organs, 2004Co-Authors: Junji Fukuda, Hiroshi Mizumoto, Toshihisa Kajiwara, Kohji Nakazawa, Kazumori FunatsuAbstract:A novel organoid culture was developed in which hepatocytes maintain high Liver functions for more than several weeks in vitro. The main disadvantage of tissue-engineered organoids is the lack of a blood vessel structure between the aggregated cells. Because of depletion of oxygen, the thickness from the surface of an organoid at which hepatocytes can survive is limited. This study showed that a rat hepatocyte organoid that forms by using centrifugal force in a hollow fiber (HF) had a survival limit thickness of about 80 - 100 microm from the surface of the organoid. Based on the value, we designed an elliptic HF having less than 150 microm minor diameter by using a simple annealing method. All hepatocytes were supplied with oxygen and formed an organoid without a dead cell layer in this HF A hepatocyte organoid in an elliptic HF maintained ammonia removal activity twice as high as in the original HF for at least one month during culture. Albumin secretion activity of an organoid in an elliptic HF was also maintained for at least one month and was the same level as that of Liver in a living body. In conclusion, organoid culture by using an elliptic HF seems to be a promising technique to develop a hybrid Artificial Liver.
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We investigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We invesigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100-200 microm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, probably because they were cultured in a serum-free medium. In the PUF module in a circulation culture, HH had high ammonia removal and low synthesis activities similar to stationary culture. Hep G2 proliferated to a high cell density, such as about 4.8 x 10(7) cells/cm3-module at 10 days of culture. Although Hep G2 spheroids had low ammonia removal activity in each cell, the removal rate in the PUF module was almost the same as for PH at 7 days of culture because of the high cell density culture by cell proliferation. The albumin secretion rate by Hep G2 in the PUF module also increased with cell proliferation and was about 10 times higher than the initial for the rate for PH at 7 days of culture. These results suggest that Hep G2 is a potential cell source PUF-HALSS.
K Okamura - One of the best experts on this subject based on the ideXlab platform.
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line hep g2 a possible cell source for hybrid Artificial Liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, Kazuhisa Ishihara, Hiroshi Mizumoto, K Okamura, Hiroyuki Ijima, Toshihisa Kajiwara, Kohji Nakazawa, Kazumori FunatsuAbstract:The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid Artificial Liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase—a urea cycle enzyme—was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volum...
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line hep g2 a possible cell source for hybrid Artificial Liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, Kazuhisa Ishihara, Hiroshi Mizumoto, K Okamura, Hiroyuki Ijima, Toshihisa Kajiwara, Kohji Nakazawa, Kanimori FunatsuAbstract:The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid Artificial Liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase--a urea cycle enzyme--was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volume of the module) of Hep G2 spheroids treated with 5 mM SB were almost the same as those of primary porcine hepatocyte spheroids. These results suggest that simultaneous use of spheroid formation and SB treatment in Hep G2 is beneficial in enhancing the functions of human hepatocytes with potential applications in regenerative medicine and drug screening.
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We investigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
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efficacy of a polyurethane foam spheroid Artificial Liver by using human hepatoblastoma cell line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, Mitsuo Shimada, K Okamura, Keizo Sugimachi, Hiroyuki Ijima, Eiji Tsujita, Ken Shirabe, Y. Yamashita, Kohji Nakazawa, Kazumori FunatsuAbstract:We invesigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid Artificial Liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100-200 microm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, probably because they were cultured in a serum-free medium. In the PUF module in a circulation culture, HH had high ammonia removal and low synthesis activities similar to stationary culture. Hep G2 proliferated to a high cell density, such as about 4.8 x 10(7) cells/cm3-module at 10 days of culture. Although Hep G2 spheroids had low ammonia removal activity in each cell, the removal rate in the PUF module was almost the same as for PH at 7 days of culture because of the high cell density culture by cell proliferation. The albumin secretion rate by Hep G2 in the PUF module also increased with cell proliferation and was about 10 times higher than the initial for the rate for PH at 7 days of culture. These results suggest that Hep G2 is a potential cell source PUF-HALSS.
