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Frank B. Cerra - One of the best experts on this subject based on the ideXlab platform.

  • Development of a Bioartificial Liver device.
    Methods in molecular medicine, 1999
    Co-Authors: Linda K. Hansen, Rory P Remmel, Julie R. Friend, Frank B. Cerra
    Abstract:

    Liver disease continues to be a challenge clinically, with 30,000 patients dying each year from Liver failure (1). Although Liver transplantation can successfully treat many patients undergoing Liver failure, the scarcity of donor organs severely limits this treatment's application. For this reason, many investigators are pursuing alternatives to total organ transplantation, from living donors to cell transplantation. One additional approach is the development of a hybrid, Bioartificial Liver as an extracorporeal device for the temporary treatment of acute Liver failure. This approach has demonstrated early success, and may provide an important clinical treatment in the near future. In addition, a Bioartificial Liver reactor is useful for prolonged in vitro studies of hepatocyte function. This chapter will provide information on the design and use of such a reactor for in vitro applications.

  • Characterization of the three-compartment gel-entrapment porcine hepatocyte Bioartificial Liver.
    Cell biology and toxicology, 1997
    Co-Authors: T D Sielaff, S L Nyberg, M D Rollins, B Amiot, A Lee, Frank B. Cerra
    Abstract:

    A hybrid Bioartificial Liver device supporting a large mass of cells expressing differentiated hepatocyte metabolic capabilities is necessary for the successful treatment of fulminant hepatic failure. The three-compartment gel-entrapment porcine hepatocyte Bioartificial Liver was designed to provide "bridge" support to transplantation or until native Liver recovery is achieved for patients with acute Liver failure. The device is an automated mammalian cell culture system supporting 6-7 x 10(9) porcine hepatocytes entrapped in a collagen matrix and inoculated into the capillary lumen spaces of two 100 kDa molecular mass cut-off hollow fiber bioreactors. Gel contraction recreates a small lumen space within the hollow fiber which allows for the deLivery of a nutrient medium. This configuration supported hepatocyte viability and differentiated phenotype as measured by albumin synthesis, ureagenesis, oxygen consumption, and vital dye staining during both cell culture and ex vivo application. The hollow fiber membrane was also shown to isolate the cells from xenogenic immunoglobulin attack. The gel-entrapment Bioartificial Liver maintained a large mass of functional hepatocytes by providing a three-dimensional cell culture matrix, by deLivering basal nutrients through lumen media perfusion, and by preventing rejection of the xenocytes. These features make this device a favorable candidate for the treatment of clinical fulminant hepatic failure.

  • gel entrapment Bioartificial Liver therapy in galactosamine hepatitis
    Journal of Surgical Research, 1995
    Co-Authors: Timothy D. Sielaff, Bruce Amiot, Mark D Rollins, Sridhar Rao, Brendan M Mcguire, Joseph R Bloomer, Frank B. Cerra
    Abstract:

    A need exists for an effective, safe Bioartificial Liver to support patients in fulminant hepatic failure (FHF). The purpose of this study was to determine the treatment efficacy of the novel gel-entrapment porcine hepatocyte Bioartificial Liver (BAL) in a fatal model of canine hepatic failure. FHF was produced in 27- to 30-kg halothane-anesthetized dogs by bolus infusion of the hepatotoxin d-galactosamine (d-Gal). Three groups were studied during the 48-hr experiment: Group d-Gal (n = 5) received galactosamine, 1.0 g/kg, iv at Time 0, Group HepBAL (n = 5) received d -Gal followed by continuous hemoperfusion with the BAL device loaded with ∼6 billion viable pig hepatocytes starting at Time 24 hr, and three dogs served as healthy controls (Group Control) and received up galactosamine. The primary endpoints were survival and coma development. Group d-Gal demonstrated 100% mortality from Liver failure by 42 hr, characterized by a progressive rise in Liver enzymes, total bilirubin, ammonia, and lactate and associated with coagulopathy, hypoglycemia, coma, and brain death. BAL therapy significantly delayed the onset of coma and improved survival (median 47 hr vs d -Gal median 36 hr). A significant delay in the rise of lactate and ammonia was also noted. BAL therapy prolonged survival and improved both laboratory and clinical markers of fatal Liver failure. These data indicate that this BAL may have clinical utility in supporting human Liver failure.

  • Formation of porcine hepatocyte spheroids for use in a Bioartificial Liver.
    Cell transplantation, 1995
    Co-Authors: Arye Lazar, Madhusudan V Peshwa, Chung Ming Chi, Frank B. Cerra
    Abstract:

    Abstract Xenogeneic hepatocytes have recently been used in a Bioartificial Liver device as a potential short-term extracorporeal support of acute Liver failure. Scaling up the system requires large quantities of viable and highly active cells. Hepatocytes grown as spheroids manifest higher metabolic activities for longer time periods as compared to those in monolayer cultures. Use of hepatocyte spheroids for application in a Bioartificial Liver can possibly alleviate the need of scaling up. Porcine hepatocytes when cultured under stirred conditions, form multicellular spheroids in a defined culture medium. Spheroids were formed 24 h after cell inoculation with an efficiency of 80–90°7o and a mean diameter of about 135 μm. Scanning electron microscopy revealed numerous microvilli projecting from the entire surface of the spheroids. Transmission electron microscopy revealed differentiated hepatocytes which displayed well-developed cytoplasmic structures separated by bile canaliculus-like structures. The morphological studies show a resemblance between cells in the spheroids and in the Liver in vivo. Ureagenesis by spheroids was twice as active and was sustained for a longer culture period than that by hepatocytes cultured as monolayers. Preparation of porcine hepatocyte spheroids in an agitated vessel is simple efficient and reproducible. It will allow for preparation of large quantities of spheroids to be employed in a Bioartificial Liver device as well as in Liver metabolism studies.

  • primary hepatocytes outperform hep g2 cells as the source of biotransformation functions in a Bioartificial Liver
    Annals of Surgery, 1994
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, Wei Shou Hu, Frank B. Cerra
    Abstract:

    OBJECTIVE: Metabolic activity of transformed human Liver (Hep G2) cells and primary rat hepatocytes were compared during in vitro application of a gel entrapment Bioartificial Liver. BACKGROUND: Clinical trials of Bioartificial Liver devices containing either transformed Liver cells or primary hepatocytes have been initiated. A study comparing transformed Liver cells and primary hepatocytes in a Bioartificial Liver under similar conditions has not been reported previously. METHODS: Gel entrapment Bioartificial Liver devices were inoculated with 100 million cells, Hep G2 cell line (n = 4), or rat hepatocytes (n = 16), and studied for up to 60 days of in vitro cultivation. RESULTS: Hep G2 cells grew to confluence within the gel entrapment configuration with a doubling time of 20 +/- 3 hours. Rat hepatocytes significantly outperformed Hep G2 cells at confluence in all categories of biotransformation, including ureagenesis (3.5 +/- 0.7 vs. 0.3 +/- 0.1 mumol/hr, p < 0.05), glucuronidation (630 +/- 75 vs. 21 +/- 2 nmol/hr, p < 0.005), sulfation (59 +/- 13 vs. 5 +/- 2 nmol/hr, p < 0.05), and oxidation (233 +/- 38 vs. < 1 nmol/hr, p < 0.005). At the conclusion of one experiment, Hep G2 cells were found in the extracapillary compartment of the Bioartificial Liver, analogous to the patient's compartment during clinical application. CONCLUSIONS: Primary rat hepatocytes were superior to the Hep G2 cell line as the source of hepatic function in a Bioartificial Liver and avoided the potential risk of tumor transmigration from the Bioartificial Liver into the patient's circulation.

Scott L Nyberg - One of the best experts on this subject based on the ideXlab platform.

  • artificial and Bioartificial Liver support
    Seminars in Liver Disease, 2008
    Co-Authors: Travis J Mckenzie, Joseph B Lillegard, Scott L Nyberg
    Abstract:

    Acute Liver failure (ALF) is a widespread problem with an unfavorable prognosis. Currently, Liver transplantation is the only direct means of treatment for patients in ALF. Due to the scarcity of donor organs, Liver support technologies are being developed and clinically tested with the intent of supporting a patient in ALF until the patient regains native Liver function or until a donor organ becomes available. Two major categories of devices are currently being tested. Artificial Liver support is purely mechanical, including albumin dialysis. Bioartificial devices contain cellular material. No single system has reproducibly demonstrated improvement in patient mortality. However, with the advent of new technology and cell acquisition techniques, further randomized controlled trials will be necessary to determine the role of artificial and Bioartificial Liver support devices in the treatment of patients with ALF.

  • Apoptotic cell death and function of cryopreserved porcine hepatocytes in a Bioartificial Liver.
    Cell transplantation, 2003
    Co-Authors: Takakazu Matsushita, Toshikazu Yagi, Joseph A. Hardin, Jennifer D. Cragun, Frank W. Crow, H. Robert Bergen, Gregory J. Gores, Scott L Nyberg
    Abstract:

    We have previously shown that cryopreservation leads to increased apoptotic death of porcine hepatocytes intended for use in a Bioartificial Liver (BAL). This study was designed to determine if a b...

  • primary hepatocytes outperform hep g2 cells as the source of biotransformation functions in a Bioartificial Liver
    Annals of Surgery, 1994
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, Wei Shou Hu, Frank B. Cerra
    Abstract:

    OBJECTIVE: Metabolic activity of transformed human Liver (Hep G2) cells and primary rat hepatocytes were compared during in vitro application of a gel entrapment Bioartificial Liver. BACKGROUND: Clinical trials of Bioartificial Liver devices containing either transformed Liver cells or primary hepatocytes have been initiated. A study comparing transformed Liver cells and primary hepatocytes in a Bioartificial Liver under similar conditions has not been reported previously. METHODS: Gel entrapment Bioartificial Liver devices were inoculated with 100 million cells, Hep G2 cell line (n = 4), or rat hepatocytes (n = 16), and studied for up to 60 days of in vitro cultivation. RESULTS: Hep G2 cells grew to confluence within the gel entrapment configuration with a doubling time of 20 +/- 3 hours. Rat hepatocytes significantly outperformed Hep G2 cells at confluence in all categories of biotransformation, including ureagenesis (3.5 +/- 0.7 vs. 0.3 +/- 0.1 mumol/hr, p < 0.05), glucuronidation (630 +/- 75 vs. 21 +/- 2 nmol/hr, p < 0.005), sulfation (59 +/- 13 vs. 5 +/- 2 nmol/hr, p < 0.05), and oxidation (233 +/- 38 vs. < 1 nmol/hr, p < 0.005). At the conclusion of one experiment, Hep G2 cells were found in the extracapillary compartment of the Bioartificial Liver, analogous to the patient's compartment during clinical application. CONCLUSIONS: Primary rat hepatocytes were superior to the Hep G2 cell line as the source of hepatic function in a Bioartificial Liver and avoided the potential risk of tumor transmigration from the Bioartificial Liver into the patient's circulation.

  • primary hepatocytes outperform hep g2 cells as the source of biotransformation functions in a Bioartificial Liver
    Annals of Surgery, 1994
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, Wei Shou Hu, Frank B. Cerra
    Abstract:

    OBJECTIVE: Metabolic activity of transformed human Liver (Hep G2) cells and primary rat hepatocytes were compared during in vitro application of a gel entrapment Bioartificial Liver. BACKGROUND: Clinical trials of Bioartificial Liver devices containing either transformed Liver cells or primary hepatocytes have been initiated. A study comparing transformed Liver cells and primary hepatocytes in a Bioartificial Liver under similar conditions has not been reported previously. METHODS: Gel entrapment Bioartificial Liver devices were inoculated with 100 million cells, Hep G2 cell line (n = 4), or rat hepatocytes (n = 16), and studied for up to 60 days of in vitro cultivation. RESULTS: Hep G2 cells grew to confluence within the gel entrapment configuration with a doubling time of 20 +/- 3 hours. Rat hepatocytes significantly outperformed Hep G2 cells at confluence in all categories of biotransformation, including ureagenesis (3.5 +/- 0.7 vs. 0.3 +/- 0.1 mumol/hr, p < 0.05), glucuronidation (630 +/- 75 vs. 21 +/- 2 nmol/hr, p < 0.005), sulfation (59 +/- 13 vs. 5 +/- 2 nmol/hr, p < 0.05), and oxidation (233 +/- 38 vs. < 1 nmol/hr, p < 0.005). At the conclusion of one experiment, Hep G2 cells were found in the extracapillary compartment of the Bioartificial Liver, analogous to the patient's compartment during clinical application. CONCLUSIONS: Primary rat hepatocytes were superior to the Hep G2 cell line as the source of hepatic function in a Bioartificial Liver and avoided the potential risk of tumor transmigration from the Bioartificial Liver into the patient's circulation.

  • Pharmacokinetic analysis verifies P450 function during in vitro and in vivo application of a Bioartificial Liver
    ASAIO journal (American Society for Artificial Internal Organs : 1992), 1993
    Co-Authors: Scott L Nyberg, Henry J Mann, Rory P Remmel, Frank B. Cerra
    Abstract:

    Lidocaine is a sensitive substrate for evaluating Liver P450 function. In this study, metabolism of lidocaine by xenogeneic hepatocytes in a hollow fiber, Bioartificial Liver was measured under in vitro conditions (n = 6) and in an anhepatic rabbit model. Animals in the treatment group (n = 6) received hemoperfusion by a Bioartificial Liver that contained 100 million rat hepatocytes. Other anhepatic rabbits received no hemoperfusion (n = 3) or a Bioartificial Liver with no cells (n = 3). Lidocaine clearance was 7.0 +/- 0.6 ml/min, and the half-life of lidocaine was 5.6 +/- 0.8 hr under in vitro conditions. Conversion of lidocaine to 3-hydroxy-lidocaine was confirmed in vitro and accounted for 46% of lidocaine elimination in the hepatocyte Bioartificial Liver. During in vivo application of the Bioartificial Liver, pharmacokinetic parameters of lidocaine metabolism, including drug half-life and metabolite formation, were significantly improved in anhepatic rabbits. 3-Hydroxy-lidocaine profiles verified the activity of a P450 isozyme expressed preferentially by rat hepatocytes in the Bioartificial Liver. We conclude that hepatic P450 activity was provided by xenogeneic hepatocytes during in vitro and in vivo applications of a Bioartificial Liver.

Madhusudan V Peshwa - One of the best experts on this subject based on the ideXlab platform.

  • Formation of porcine hepatocyte spheroids for use in a Bioartificial Liver.
    Cell transplantation, 1995
    Co-Authors: Arye Lazar, Madhusudan V Peshwa, Chung Ming Chi, Frank B. Cerra
    Abstract:

    Abstract Xenogeneic hepatocytes have recently been used in a Bioartificial Liver device as a potential short-term extracorporeal support of acute Liver failure. Scaling up the system requires large quantities of viable and highly active cells. Hepatocytes grown as spheroids manifest higher metabolic activities for longer time periods as compared to those in monolayer cultures. Use of hepatocyte spheroids for application in a Bioartificial Liver can possibly alleviate the need of scaling up. Porcine hepatocytes when cultured under stirred conditions, form multicellular spheroids in a defined culture medium. Spheroids were formed 24 h after cell inoculation with an efficiency of 80–90°7o and a mean diameter of about 135 μm. Scanning electron microscopy revealed numerous microvilli projecting from the entire surface of the spheroids. Transmission electron microscopy revealed differentiated hepatocytes which displayed well-developed cytoplasmic structures separated by bile canaliculus-like structures. The morphological studies show a resemblance between cells in the spheroids and in the Liver in vivo. Ureagenesis by spheroids was twice as active and was sustained for a longer culture period than that by hepatocytes cultured as monolayers. Preparation of porcine hepatocyte spheroids in an agitated vessel is simple efficient and reproducible. It will allow for preparation of large quantities of spheroids to be employed in a Bioartificial Liver device as well as in Liver metabolism studies.

  • primary hepatocytes outperform hep g2 cells as the source of biotransformation functions in a Bioartificial Liver
    Annals of Surgery, 1994
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, Wei Shou Hu, Frank B. Cerra
    Abstract:

    OBJECTIVE: Metabolic activity of transformed human Liver (Hep G2) cells and primary rat hepatocytes were compared during in vitro application of a gel entrapment Bioartificial Liver. BACKGROUND: Clinical trials of Bioartificial Liver devices containing either transformed Liver cells or primary hepatocytes have been initiated. A study comparing transformed Liver cells and primary hepatocytes in a Bioartificial Liver under similar conditions has not been reported previously. METHODS: Gel entrapment Bioartificial Liver devices were inoculated with 100 million cells, Hep G2 cell line (n = 4), or rat hepatocytes (n = 16), and studied for up to 60 days of in vitro cultivation. RESULTS: Hep G2 cells grew to confluence within the gel entrapment configuration with a doubling time of 20 +/- 3 hours. Rat hepatocytes significantly outperformed Hep G2 cells at confluence in all categories of biotransformation, including ureagenesis (3.5 +/- 0.7 vs. 0.3 +/- 0.1 mumol/hr, p < 0.05), glucuronidation (630 +/- 75 vs. 21 +/- 2 nmol/hr, p < 0.005), sulfation (59 +/- 13 vs. 5 +/- 2 nmol/hr, p < 0.05), and oxidation (233 +/- 38 vs. < 1 nmol/hr, p < 0.005). At the conclusion of one experiment, Hep G2 cells were found in the extracapillary compartment of the Bioartificial Liver, analogous to the patient's compartment during clinical application. CONCLUSIONS: Primary rat hepatocytes were superior to the Hep G2 cell line as the source of hepatic function in a Bioartificial Liver and avoided the potential risk of tumor transmigration from the Bioartificial Liver into the patient's circulation.

  • primary hepatocytes outperform hep g2 cells as the source of biotransformation functions in a Bioartificial Liver
    Annals of Surgery, 1994
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, Wei Shou Hu, Frank B. Cerra
    Abstract:

    OBJECTIVE: Metabolic activity of transformed human Liver (Hep G2) cells and primary rat hepatocytes were compared during in vitro application of a gel entrapment Bioartificial Liver. BACKGROUND: Clinical trials of Bioartificial Liver devices containing either transformed Liver cells or primary hepatocytes have been initiated. A study comparing transformed Liver cells and primary hepatocytes in a Bioartificial Liver under similar conditions has not been reported previously. METHODS: Gel entrapment Bioartificial Liver devices were inoculated with 100 million cells, Hep G2 cell line (n = 4), or rat hepatocytes (n = 16), and studied for up to 60 days of in vitro cultivation. RESULTS: Hep G2 cells grew to confluence within the gel entrapment configuration with a doubling time of 20 +/- 3 hours. Rat hepatocytes significantly outperformed Hep G2 cells at confluence in all categories of biotransformation, including ureagenesis (3.5 +/- 0.7 vs. 0.3 +/- 0.1 mumol/hr, p < 0.05), glucuronidation (630 +/- 75 vs. 21 +/- 2 nmol/hr, p < 0.005), sulfation (59 +/- 13 vs. 5 +/- 2 nmol/hr, p < 0.05), and oxidation (233 +/- 38 vs. < 1 nmol/hr, p < 0.005). At the conclusion of one experiment, Hep G2 cells were found in the extracapillary compartment of the Bioartificial Liver, analogous to the patient's compartment during clinical application. CONCLUSIONS: Primary rat hepatocytes were superior to the Hep G2 cell line as the source of hepatic function in a Bioartificial Liver and avoided the potential risk of tumor transmigration from the Bioartificial Liver into the patient's circulation.

  • Evolution of the Bioartificial Liver: The need for randomized clinical trials
    American journal of surgery, 1993
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, William D. Payne, Frank B. Cerra
    Abstract:

    The pursuit of a Bioartificial Liver is well documented in the literature. Early techniques of artificial Liver support that have undergone clinical testing included simple exchange transfusions, extracorporeal xenogeneic or allogeneic Liver perfusion, cross-circulation, hemodialysis, charcoal hemoperfusion, and plasmapheresis with plasma exchange. These techniques failed because they were unable to adequately support those hepatic functions essential for survival and because they lacked a back-up therapy, such as Liver transplantation, for irreversible forms of Liver disease. The concept evolved that hepatic functions essential for survival would be best performed by hepatocytes in an apparatus that allowed sustained or repetitive application. The best results have been achieved with Bioartificial Liver technologies that employ hepatocytes as implantable systems or extracorporeal devices. Implantable Bioartificial Liver systems include hepatocytes that have been on coated microcarrier beads, within microencapsulated gel droplets, within biodegradable polymeric substrates, or as spheroid hepatocyte aggregates. Extracorporeal systems include hepatocytes in suspension, on flat plates, and in hollow fiber bioreactors. Several extracorporeal systems have undergone extensive animal testing and are entering the early stages of human clinical trials. Randomized trials are needed to establish the value of Bioartificial Liver support in the treatment of patients with acute hepatic failure or as a bridge to Liver transplantation.

  • Extracorporeal application of a gel-entrapment, Bioartificial Liver: Demonstration of drug metabolism and other biochemical functions
    Cell transplantation, 1993
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, William D. Payne, Timothy D. Sielaff, Ken Shirabe, Paul L. Crotty, Frank B. Cerra
    Abstract:

    Metabolic activity of a gel-entrapment, hollow fiber, Bioartificial Liver was evaluated in vitro and during extracorporeal hemoperfusion in an anhepatic rabbit model. The Bioartificial Liver contained either 100 million rat hepatocytes (n = 12), fibroblasts (n = 3), or no cells (n = 7) during hemoperfusion of anhepatic rabbits. Eight other anhepatic rabbits were studied without hemoperfusion as anhepatic controls, and three sham rabbits served as normal controls. Albumin production rates (mean +/- SEM) were similar during in vitro (17.0 +/- 2.8 micrograms/h) and extracorporeal (18.0 +/- 4.0 micrograms/h) application of the hepatocyte Bioartificial Liver. Exogenous glucose requirements were reduced (p < 0.01) and euglycemia was prolonged (p < 0.001) in anhepatic rabbits treated with the hepatocyte Bioartificial Liver. The maximum rate of glucose production by the hepatocyte Bioartificial Liver ranged from 50-80 micrograms/h. Plasma concentrations of aromatic amino acids, proline, alanine, and ammonia were normalized in anhepatic rabbits during hepatocyte hemoperfusion. Gel-entrapped hepatocytes in the bioartifical Liver performed sulfation and glucuronidation of 4-methylumbelliferone. P450 activity was demonstrated during both in vitro and extracorporeal application of the BAL device by the formation of 3-hydroxy-lidocaine, the major metabolite of lidocaine biotransformation by gel-entrapped rat hepatocytes. In summary, a gel-entrapment, Bioartificial Liver performed multiple hepatocyte-specific functions without adverse side effects during extracorporeal application in an anhepatic, small animal model. With its potential for short term support of acute Liver failure, scale-up of the current Bioartificial Liver device is indicated for further investigations in large animal, preclinical trials.

Rory P Remmel - One of the best experts on this subject based on the ideXlab platform.

  • Development of a Bioartificial Liver device.
    Methods in molecular medicine, 1999
    Co-Authors: Linda K. Hansen, Rory P Remmel, Julie R. Friend, Frank B. Cerra
    Abstract:

    Liver disease continues to be a challenge clinically, with 30,000 patients dying each year from Liver failure (1). Although Liver transplantation can successfully treat many patients undergoing Liver failure, the scarcity of donor organs severely limits this treatment's application. For this reason, many investigators are pursuing alternatives to total organ transplantation, from living donors to cell transplantation. One additional approach is the development of a hybrid, Bioartificial Liver as an extracorporeal device for the temporary treatment of acute Liver failure. This approach has demonstrated early success, and may provide an important clinical treatment in the near future. In addition, a Bioartificial Liver reactor is useful for prolonged in vitro studies of hepatocyte function. This chapter will provide information on the design and use of such a reactor for in vitro applications.

  • primary hepatocytes outperform hep g2 cells as the source of biotransformation functions in a Bioartificial Liver
    Annals of Surgery, 1994
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, Wei Shou Hu, Frank B. Cerra
    Abstract:

    OBJECTIVE: Metabolic activity of transformed human Liver (Hep G2) cells and primary rat hepatocytes were compared during in vitro application of a gel entrapment Bioartificial Liver. BACKGROUND: Clinical trials of Bioartificial Liver devices containing either transformed Liver cells or primary hepatocytes have been initiated. A study comparing transformed Liver cells and primary hepatocytes in a Bioartificial Liver under similar conditions has not been reported previously. METHODS: Gel entrapment Bioartificial Liver devices were inoculated with 100 million cells, Hep G2 cell line (n = 4), or rat hepatocytes (n = 16), and studied for up to 60 days of in vitro cultivation. RESULTS: Hep G2 cells grew to confluence within the gel entrapment configuration with a doubling time of 20 +/- 3 hours. Rat hepatocytes significantly outperformed Hep G2 cells at confluence in all categories of biotransformation, including ureagenesis (3.5 +/- 0.7 vs. 0.3 +/- 0.1 mumol/hr, p < 0.05), glucuronidation (630 +/- 75 vs. 21 +/- 2 nmol/hr, p < 0.005), sulfation (59 +/- 13 vs. 5 +/- 2 nmol/hr, p < 0.05), and oxidation (233 +/- 38 vs. < 1 nmol/hr, p < 0.005). At the conclusion of one experiment, Hep G2 cells were found in the extracapillary compartment of the Bioartificial Liver, analogous to the patient's compartment during clinical application. CONCLUSIONS: Primary rat hepatocytes were superior to the Hep G2 cell line as the source of hepatic function in a Bioartificial Liver and avoided the potential risk of tumor transmigration from the Bioartificial Liver into the patient's circulation.

  • primary hepatocytes outperform hep g2 cells as the source of biotransformation functions in a Bioartificial Liver
    Annals of Surgery, 1994
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, Wei Shou Hu, Frank B. Cerra
    Abstract:

    OBJECTIVE: Metabolic activity of transformed human Liver (Hep G2) cells and primary rat hepatocytes were compared during in vitro application of a gel entrapment Bioartificial Liver. BACKGROUND: Clinical trials of Bioartificial Liver devices containing either transformed Liver cells or primary hepatocytes have been initiated. A study comparing transformed Liver cells and primary hepatocytes in a Bioartificial Liver under similar conditions has not been reported previously. METHODS: Gel entrapment Bioartificial Liver devices were inoculated with 100 million cells, Hep G2 cell line (n = 4), or rat hepatocytes (n = 16), and studied for up to 60 days of in vitro cultivation. RESULTS: Hep G2 cells grew to confluence within the gel entrapment configuration with a doubling time of 20 +/- 3 hours. Rat hepatocytes significantly outperformed Hep G2 cells at confluence in all categories of biotransformation, including ureagenesis (3.5 +/- 0.7 vs. 0.3 +/- 0.1 mumol/hr, p < 0.05), glucuronidation (630 +/- 75 vs. 21 +/- 2 nmol/hr, p < 0.005), sulfation (59 +/- 13 vs. 5 +/- 2 nmol/hr, p < 0.05), and oxidation (233 +/- 38 vs. < 1 nmol/hr, p < 0.005). At the conclusion of one experiment, Hep G2 cells were found in the extracapillary compartment of the Bioartificial Liver, analogous to the patient's compartment during clinical application. CONCLUSIONS: Primary rat hepatocytes were superior to the Hep G2 cell line as the source of hepatic function in a Bioartificial Liver and avoided the potential risk of tumor transmigration from the Bioartificial Liver into the patient's circulation.

  • Pharmacokinetic analysis verifies P450 function during in vitro and in vivo application of a Bioartificial Liver
    ASAIO journal (American Society for Artificial Internal Organs : 1992), 1993
    Co-Authors: Scott L Nyberg, Henry J Mann, Rory P Remmel, Frank B. Cerra
    Abstract:

    Lidocaine is a sensitive substrate for evaluating Liver P450 function. In this study, metabolism of lidocaine by xenogeneic hepatocytes in a hollow fiber, Bioartificial Liver was measured under in vitro conditions (n = 6) and in an anhepatic rabbit model. Animals in the treatment group (n = 6) received hemoperfusion by a Bioartificial Liver that contained 100 million rat hepatocytes. Other anhepatic rabbits received no hemoperfusion (n = 3) or a Bioartificial Liver with no cells (n = 3). Lidocaine clearance was 7.0 +/- 0.6 ml/min, and the half-life of lidocaine was 5.6 +/- 0.8 hr under in vitro conditions. Conversion of lidocaine to 3-hydroxy-lidocaine was confirmed in vitro and accounted for 46% of lidocaine elimination in the hepatocyte Bioartificial Liver. During in vivo application of the Bioartificial Liver, pharmacokinetic parameters of lidocaine metabolism, including drug half-life and metabolite formation, were significantly improved in anhepatic rabbits. 3-Hydroxy-lidocaine profiles verified the activity of a P450 isozyme expressed preferentially by rat hepatocytes in the Bioartificial Liver. We conclude that hepatic P450 activity was provided by xenogeneic hepatocytes during in vitro and in vivo applications of a Bioartificial Liver.

  • Extracorporeal application of a gel-entrapment, Bioartificial Liver: Demonstration of drug metabolism and other biochemical functions
    Cell transplantation, 1993
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, William D. Payne, Timothy D. Sielaff, Ken Shirabe, Paul L. Crotty, Frank B. Cerra
    Abstract:

    Metabolic activity of a gel-entrapment, hollow fiber, Bioartificial Liver was evaluated in vitro and during extracorporeal hemoperfusion in an anhepatic rabbit model. The Bioartificial Liver contained either 100 million rat hepatocytes (n = 12), fibroblasts (n = 3), or no cells (n = 7) during hemoperfusion of anhepatic rabbits. Eight other anhepatic rabbits were studied without hemoperfusion as anhepatic controls, and three sham rabbits served as normal controls. Albumin production rates (mean +/- SEM) were similar during in vitro (17.0 +/- 2.8 micrograms/h) and extracorporeal (18.0 +/- 4.0 micrograms/h) application of the hepatocyte Bioartificial Liver. Exogenous glucose requirements were reduced (p < 0.01) and euglycemia was prolonged (p < 0.001) in anhepatic rabbits treated with the hepatocyte Bioartificial Liver. The maximum rate of glucose production by the hepatocyte Bioartificial Liver ranged from 50-80 micrograms/h. Plasma concentrations of aromatic amino acids, proline, alanine, and ammonia were normalized in anhepatic rabbits during hepatocyte hemoperfusion. Gel-entrapped hepatocytes in the bioartifical Liver performed sulfation and glucuronidation of 4-methylumbelliferone. P450 activity was demonstrated during both in vitro and extracorporeal application of the BAL device by the formation of 3-hydroxy-lidocaine, the major metabolite of lidocaine biotransformation by gel-entrapped rat hepatocytes. In summary, a gel-entrapment, Bioartificial Liver performed multiple hepatocyte-specific functions without adverse side effects during extracorporeal application in an anhepatic, small animal model. With its potential for short term support of acute Liver failure, scale-up of the current Bioartificial Liver device is indicated for further investigations in large animal, preclinical trials.

Henry J Mann - One of the best experts on this subject based on the ideXlab platform.

  • primary hepatocytes outperform hep g2 cells as the source of biotransformation functions in a Bioartificial Liver
    Annals of Surgery, 1994
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, Wei Shou Hu, Frank B. Cerra
    Abstract:

    OBJECTIVE: Metabolic activity of transformed human Liver (Hep G2) cells and primary rat hepatocytes were compared during in vitro application of a gel entrapment Bioartificial Liver. BACKGROUND: Clinical trials of Bioartificial Liver devices containing either transformed Liver cells or primary hepatocytes have been initiated. A study comparing transformed Liver cells and primary hepatocytes in a Bioartificial Liver under similar conditions has not been reported previously. METHODS: Gel entrapment Bioartificial Liver devices were inoculated with 100 million cells, Hep G2 cell line (n = 4), or rat hepatocytes (n = 16), and studied for up to 60 days of in vitro cultivation. RESULTS: Hep G2 cells grew to confluence within the gel entrapment configuration with a doubling time of 20 +/- 3 hours. Rat hepatocytes significantly outperformed Hep G2 cells at confluence in all categories of biotransformation, including ureagenesis (3.5 +/- 0.7 vs. 0.3 +/- 0.1 mumol/hr, p < 0.05), glucuronidation (630 +/- 75 vs. 21 +/- 2 nmol/hr, p < 0.005), sulfation (59 +/- 13 vs. 5 +/- 2 nmol/hr, p < 0.05), and oxidation (233 +/- 38 vs. < 1 nmol/hr, p < 0.005). At the conclusion of one experiment, Hep G2 cells were found in the extracapillary compartment of the Bioartificial Liver, analogous to the patient's compartment during clinical application. CONCLUSIONS: Primary rat hepatocytes were superior to the Hep G2 cell line as the source of hepatic function in a Bioartificial Liver and avoided the potential risk of tumor transmigration from the Bioartificial Liver into the patient's circulation.

  • primary hepatocytes outperform hep g2 cells as the source of biotransformation functions in a Bioartificial Liver
    Annals of Surgery, 1994
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, Wei Shou Hu, Frank B. Cerra
    Abstract:

    OBJECTIVE: Metabolic activity of transformed human Liver (Hep G2) cells and primary rat hepatocytes were compared during in vitro application of a gel entrapment Bioartificial Liver. BACKGROUND: Clinical trials of Bioartificial Liver devices containing either transformed Liver cells or primary hepatocytes have been initiated. A study comparing transformed Liver cells and primary hepatocytes in a Bioartificial Liver under similar conditions has not been reported previously. METHODS: Gel entrapment Bioartificial Liver devices were inoculated with 100 million cells, Hep G2 cell line (n = 4), or rat hepatocytes (n = 16), and studied for up to 60 days of in vitro cultivation. RESULTS: Hep G2 cells grew to confluence within the gel entrapment configuration with a doubling time of 20 +/- 3 hours. Rat hepatocytes significantly outperformed Hep G2 cells at confluence in all categories of biotransformation, including ureagenesis (3.5 +/- 0.7 vs. 0.3 +/- 0.1 mumol/hr, p < 0.05), glucuronidation (630 +/- 75 vs. 21 +/- 2 nmol/hr, p < 0.005), sulfation (59 +/- 13 vs. 5 +/- 2 nmol/hr, p < 0.05), and oxidation (233 +/- 38 vs. < 1 nmol/hr, p < 0.005). At the conclusion of one experiment, Hep G2 cells were found in the extracapillary compartment of the Bioartificial Liver, analogous to the patient's compartment during clinical application. CONCLUSIONS: Primary rat hepatocytes were superior to the Hep G2 cell line as the source of hepatic function in a Bioartificial Liver and avoided the potential risk of tumor transmigration from the Bioartificial Liver into the patient's circulation.

  • Pharmacokinetic analysis verifies P450 function during in vitro and in vivo application of a Bioartificial Liver
    ASAIO journal (American Society for Artificial Internal Organs : 1992), 1993
    Co-Authors: Scott L Nyberg, Henry J Mann, Rory P Remmel, Frank B. Cerra
    Abstract:

    Lidocaine is a sensitive substrate for evaluating Liver P450 function. In this study, metabolism of lidocaine by xenogeneic hepatocytes in a hollow fiber, Bioartificial Liver was measured under in vitro conditions (n = 6) and in an anhepatic rabbit model. Animals in the treatment group (n = 6) received hemoperfusion by a Bioartificial Liver that contained 100 million rat hepatocytes. Other anhepatic rabbits received no hemoperfusion (n = 3) or a Bioartificial Liver with no cells (n = 3). Lidocaine clearance was 7.0 +/- 0.6 ml/min, and the half-life of lidocaine was 5.6 +/- 0.8 hr under in vitro conditions. Conversion of lidocaine to 3-hydroxy-lidocaine was confirmed in vitro and accounted for 46% of lidocaine elimination in the hepatocyte Bioartificial Liver. During in vivo application of the Bioartificial Liver, pharmacokinetic parameters of lidocaine metabolism, including drug half-life and metabolite formation, were significantly improved in anhepatic rabbits. 3-Hydroxy-lidocaine profiles verified the activity of a P450 isozyme expressed preferentially by rat hepatocytes in the Bioartificial Liver. We conclude that hepatic P450 activity was provided by xenogeneic hepatocytes during in vitro and in vivo applications of a Bioartificial Liver.

  • Extracorporeal application of a gel-entrapment, Bioartificial Liver: Demonstration of drug metabolism and other biochemical functions
    Cell transplantation, 1993
    Co-Authors: Scott L Nyberg, Madhusudan V Peshwa, Henry J Mann, Rory P Remmel, William D. Payne, Timothy D. Sielaff, Ken Shirabe, Paul L. Crotty, Frank B. Cerra
    Abstract:

    Metabolic activity of a gel-entrapment, hollow fiber, Bioartificial Liver was evaluated in vitro and during extracorporeal hemoperfusion in an anhepatic rabbit model. The Bioartificial Liver contained either 100 million rat hepatocytes (n = 12), fibroblasts (n = 3), or no cells (n = 7) during hemoperfusion of anhepatic rabbits. Eight other anhepatic rabbits were studied without hemoperfusion as anhepatic controls, and three sham rabbits served as normal controls. Albumin production rates (mean +/- SEM) were similar during in vitro (17.0 +/- 2.8 micrograms/h) and extracorporeal (18.0 +/- 4.0 micrograms/h) application of the hepatocyte Bioartificial Liver. Exogenous glucose requirements were reduced (p < 0.01) and euglycemia was prolonged (p < 0.001) in anhepatic rabbits treated with the hepatocyte Bioartificial Liver. The maximum rate of glucose production by the hepatocyte Bioartificial Liver ranged from 50-80 micrograms/h. Plasma concentrations of aromatic amino acids, proline, alanine, and ammonia were normalized in anhepatic rabbits during hepatocyte hemoperfusion. Gel-entrapped hepatocytes in the bioartifical Liver performed sulfation and glucuronidation of 4-methylumbelliferone. P450 activity was demonstrated during both in vitro and extracorporeal application of the BAL device by the formation of 3-hydroxy-lidocaine, the major metabolite of lidocaine biotransformation by gel-entrapped rat hepatocytes. In summary, a gel-entrapment, Bioartificial Liver performed multiple hepatocyte-specific functions without adverse side effects during extracorporeal application in an anhepatic, small animal model. With its potential for short term support of acute Liver failure, scale-up of the current Bioartificial Liver device is indicated for further investigations in large animal, preclinical trials.