Abstract: A method is provided of propagating hepatic cells including hepatic progenitors ex vivo on or in hyaluronans with or without other extracellular matrix components (such as collagens, basal adhesion molecules, proteoglycans or their glycosaminoglycans) and with or without hormones and/or growth factors. Compositions comprising the matrix are also disclosed. Also, the complex can be used for ex vivo tissue engineering or can be used as a scaffold for grafts of cells to be transplanted in vivo.

Abstract: Hepatic progenitors comprise two populations of human hepatic stem cells, primitive and proximal hepatic stem cells, and two populations of committed progenitors, one for biliary cells and one for hepatocytes. Human primitive hepatic stem cells are a very small fraction of the liver cell population and give rise to proximal hepatic stem cells constituting a much larger fraction of the liver. Human proximal hepatic stem cells give rise to biliary and hepatocyte committed progenitors. Primitive and proximal stem cells are the primary stem cells for the human liver. Human primitive hepatic stem cells may be isolated by immunoselection from human livers or culturing human liver cells under conditions which select for a human primitive hepatic stem cell. Proximal hepatic stem cells may be isolated by immunoselection, or by culturing human liver cells under conditions which include a developmental factor.

Abstract: The invention discloses the sequences of variant forms of alpha-fetoprotein transcripts that have been identified in human hemopoietic progenitors but not in differentiated mature cells. The variant forms of AFP (vAFP) cDNA sequences isolated from a multipotent hemopoietic cell line, K562, differ from the authentic AFP transcript, consisting of 15 exons, by lacking only exon 1. Instead of exon 1, vAFP transcripts use an additional one or two exons located in the 5?-untranslated region of the AFP gene. K562 expressed selectively vAFP, whereas a hepatocellular carcinoma cell line, HepG2, showed no detectable expression of vAFP. In normal adult tissues, vAFP transcripts is detected in the bone marrow, thymus and brain, but not the spleen, suggesting the expression occurs in normal hemopoietic progenitors. Moreover, CD34+Lin? hemopoietic stem/progenitor cells purified by flow cytometric sorting also express the variant transcripts.

Abstract: This invention relates to methods of isolating hepatoblasts utilizing panning techniques and fluorescence activated cell sorting. This invention further relates to isolated hepatoblasts and to a method of treating liver dysfunction as well as to methods of forming artificial livers.

Abstract: A bioreactor for three-dimensional culture of liver cells is disclosed. The device is characterized by the use of textile vasculatures. A model and method for optimizing vasculature parameters is also disclosed. Liver acinar structure and physiological parameters are mimicked by sandwiching cells in the space between the two innermost woven textile hollow fibers, and creating radial flow of media from an outer compartment, through the cell mass compartment, and to an inner compartment. The theoretical optimum hydraulic permeability for the two innermost semi-permeable membranes is determined based on physiological hepatic sinusoidal blood flow and pressures. Experimental studies using a flow rate and pressure monitoring systems in conjunction with phase-contrast velocity-encoded MRI confirm theoretical results. Novel woven vascular tubes with optimum hydraulic permeability are disclosed for culturing hepatocytes in the multi-coaxial bioreactor.

Abstract: The present invention is directed toward a method for obtaining from whole liver or a resection thereof a population of cells comprising viable, functional liver cells enriched in hepatocytes and hepatocyte stem/progenitor cells, compositions thereof, and uses therefore. Compositions include a composition of liver cells enriched in hepatocytes and hepatocyte stem/progenitor cells and a pharmaceutical composition thereof. Uses include treatment of liver diseases, regeneration of liver, toxicity testing, and liver assist devices.

Abstract: A composition which comprises an animal cell population which contains immature animal cells. The immature animal cells are characterized by expression of alpha-fetoprotein or lack of essential expression of alpha-fetoprotein and albumin, and at least a portion of said immature animal cells or at least a portion of the progeny of said immature animal cells is capable of differentiating into cells which express albumin. The cell population is cultured under conditions which result in expansion of the cells. Expansion of the cells may be achieved by culturing the cells in the presence of an extracellular matrix and liver stromal cells; and preferably in the presence of growth factors. Such cells may be used for liver transplantation, artificial livers, and for toxicology and pharmacology studies. Such cells may also be genetically engineered to express proteins or polypepetides of interest.

Abstract: A method of obtaining a mixture of cells enriched in hepatic progenitors is developed which comprises methods yielding suspensions of a mixture of cell types, and selecting those cells that are classical MHC class I antigen(s) negative and ICAM-1 antigen positive. The weak or dull expression of nonclassical MHC class I antigen(s) can be used for further enrichment of hepatic progenitors. Furthermore, the progenitors can be selected to have a level of side scatter, a measure of granularity or cytoplasmic droplets, that is higher than that in non-parenchymal cells, such as hemopoietic cells, and lower than that in mature parenchymal cells, such as hepatocytes. Furthermore, the progeny of the isolated progenitors can express alpha-fetoprotein and/or albumin and/or CK19. The hepatic progenitors, so isolated, can grow clonally, that is an entire population of progeny can be derived from one cell. The clones of progenitors have a growth pattern in culture of piled-up aggregates or clusters.

Abstract: This invention relates to methods of isolating hepatoblasts utilizing panning techniques and fluorescence activated cell sorting. This invention further relates to isolated hepatoblasts and to a method of treating liver dysfunction as well as to methods of forming artificial livers.

Abstract: A method of propagating mammalian endodermally derived progenitors such as hepatic progenitors, their progeny, or mixtures thereof is developed which includes culturing mammalian progenitors, their progeny, or mixtures thereof on a layer of embryonic mammalian feeder cells in a culture medium. The culture medium can be supplemented with one or more hormones and other growth agents. These hormones and other growth agents can include insulin, dexamethasone, transferrin, nicotinamide, serum albumin, &bgr;-mercaptoethanol, free fatty acid, glutamine, CUSO4, and H2SeO3. The culture medium can also include antibiotics. Importantly, the culture medium does not include serum.

Abstract: A method of obtaining a mixture of cells enriched in hepatic progenitors is developed which comprises methods yielding suspensions of a mixture of cell types, and selecting those cells that are classical MHC class I antigen(s) negative and ICAM-1 antigen positive. The weak or dull expression of nonclassical MHC class I antigen(s) can be used for further enrichment of hepatic progenitors. Furthermore, the progenitors can be selected to have a level of side scatter, a measure of granularity or cytoplasmic droplets, that is higher than that in non-parenchymal cells, such as hemopoietic cells, and lower than that in mature parenchymal cells, such as hepatocytes. Furthermore, the progeny of the isolated progenitors can express alpha-fetoprotein and/or albumin and/or CK19. The hepatic progenitors, so isolated, can grow clonally, that is an entire population of progeny can be derived from one cell. The clones of progenitors have a growth pattern in culture of piled-up aggregates or clusters.

Abstract: Methods of isolating and cryopreserving progenitors from human liver are disclosed which include processing human liver tissue to provide a substantially single cell suspension comprising progenitors and non-progenitors of one or more cell lineages found in human liver; subjecting the suspension to a debulking step, which reduces substantially the number of non-progenitors in the suspension, and which provides a debulked suspension enriched in progenitors exhibiting one or more markers associated with at least one of the one or more cell lineages; and selecting from said debulked suspension those cells, which themselves, their progeny, or more mature forms thereof express one or more markers associated with at least one of the one or more cell lineages. Among these markers are CD14, CD34, CD38, CD 45, and ICAM.

Abstract: The present invention provides compositions comprising cells that can effectively produce HCV after HCV infection, compositions for culturing the cells, methods for making the composition and methods for infecting the cells in the composition with HCV. The present invention also provides methods for assaying HCV production and methods for evaluating compounds that affect the production of HCV.

Abstract: The instant invention provides, for the first time, the use of cadaveric organs from donors with non-beating hearts as a source of functional cells such as progenitor or stem cells for various medical purposes. More specifically, a method is disclosed whereby a tissue source of progenitor cells is obtained comprising harvesting tissue from a donor, wherein the donor has a non-beating heart for as long as about thirty hours postmortem and processing the cadaveric tissue to provide progenitor cells. The instant progenitors are used for various medical purposes as means of cell therapy, gene therapy, artificial organs, bioreactors, organ regeneration and the like.

Abstract: This invention relates to methods of isolating hepatoblasts utilizing panning techniques and fluorescence activated cell sorting. This invention further relates to isolated hepatoblasts and to a method of treating liver dysfunction as well as to methods of forming artificial livers.

Abstract: A composition which comprises an animal cell population which contains immature animal cells. The immature animal cells are characterized by expression of alpha-fetoprotein or lack of essential expression of alpha-fetoprotein and albumin, and at least a portion of said immature animal cells or at least a portion of the progeny of said immature animal cells is capable of differentiating into cells which express albumin. The cell population is cultured under conditions which result in expansion of the cells. Expansion of the cells may be achieved by culturing the cells in the presence of an extracellular matrix and liver stromal cells; and preferably in the presence of growth factors. Such cells may be used for liver transplantation, artificial livers, and for toxicology and pharmacology studies. Such cells may also be genetically engineered to express proteins or polypepetides of interest.

Abstract: This invention relates to methods of isolating hepatic progenitors utilizing panning techniques and fluorescence activated cell sorting. This invention further relates to isolated hepatic progenitors and to a method of treating liver dysfunction as well as to methods of forming artificial livers.

Abstract: A composition which comprises an animal cell population which contains immature animal cells. The immature animal cells are characterized by expression of alpha-fetoprotein or lack of essential expression of alpha-fetoprotein and albumin, and at least a portion of said immature animal cells or at least a portion of the progeny of said immature animal cells is capable of differentiating into cells which express albumin. The cell population is cultured under conditions which result in expansion of the cells. Expansion of the cells may be achieved by culturing the cells in the presence of an extracellular matrix and liver stromal cells; and preferably in the presence of growth factors. Such cells may be used for liver transplantation, artificial livers, and for toxicology and pharmacology studies. Such cells may also be genetically engineered to express proteins or polypepetides of interest.

Abstract: This invention relates to methods of isolating hepatoblasts utilizing panning techniques and fluorescence activated cell sorting. This invention further relates to isolated hepatoblasts and to a method of treating liver dysfunction as well as to methods of forming artificial livers.

Abstract: A composition which comprises an animal cell population, and which contains immature animal cells. The immature animal cells are characterized by expression of alpha-fetoprotein or lack of essential expression of alpha-fetoprotein and albumin, and at least a portion of said immature animal cells or at least a portion of the progeny of said immature cells is capable of differentiating into cells which express albumin. The cell population is cultured under conditions which result in expansion of the cells. Expansion of the cells may be achieved by culturing the cells in the presence of an extracellular matrix and liver stromal cells; and preferably in the presence of growth factors. Such cells may be used for liver transplantation, artificial livers, and for toxicology and pharmacology studies. Such cells may also be genetically engineered to express proteins or polypeptides of interest.