Tissue engineering liver cell transplantation

Hepatocytes are a cell-type, of particular interest in tissue engineering due to the regenerative capacity of the liver and the quantity of waiting liver transplant recipients, for which there are too few available organ donors. While the asialoglycoprotein receptor on hepatocytes does not... 

Despite these failures, the need still exists for alternative liver therapies. Several new techniques including cell transplantation, tissue-engineered constructs, and extra- and paracorporeal devices seek to relieve some of the demands placed on a compromised liver. Liver assist devices allow the liver to regenerate its function by removing some of the demands. Bridge-to-transplant devices seek to maintain patients until suitable donors are available. Some therapies seek to remove toxins from the blood, and they have a place in the treatment scheme, but due to the complex and multifunctional nature of the organ, some type of cell-based therapy is considered a more complete solution. 

An alternative approach to broaden the availability of immunocompatible cells is to use stem cells that have the potential to differentiate into various cell types and also can be genetically manipulated because of their inherent self-renewal property. Thus, one could hope for the availability of functionally replaceable tissues off the shelf. Efficacy of using stem cells has been clinically proven beneficial in treating a variety of blood-related disorders. Furthermore, plasticity of stem cells has also been demonstrated in various animal models, suggesting that stem cells from one tissue type can be converted into cells of other tissues as well for example, when bone marrow cells were transplanted into liver-injured animals, these cells restored the liver by differentiating into liver cells. However, there is a need to engineer in vitro systems that can provide various microenvironments conducive to drive stem cells to defined cell types and then colonize them to generate needed tissue parts. 

Risbud, M. V., E. Karamuk, R. Moser, and J. Mayer. 2002. Hydrogel-coated textile scaffolds as three-dimensional growth support for human umbihcal vein endothelial cells (HUVECs) possibilities as coculture system in liver tissue engineering. Cell Transplant 11 369-377. 

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