Hepatocyte Isolation, Culture, and Its Clinical Applications / 한양의대학술지

Hepatocytes, parenchymal cells of the liver, are specially differentiated cells to perform most of the body metabolisms. Many clinicians are interested in utilizing hepatocytes as cell therapeutics. A great number of investigators have been harvesting hepatocytes using two-step portal vein perfusion method, in which Ca2+-free EDTA-containing buffer and Ca2+-enriched collagenase solution are pumped into liver in sequence. Among various attempts for long-term culture of hepatocytes, collagen gel sandwich configuration is recognized to be the most effective technique. In the biomedical field, hepatocytes have been used in three methods of applications. First is hepatocyte transplantation for the treatment of acute, chronic liver failure and metabolic diseases. Donated livers not suitable for organ transplantation are rare, which is the major human hepatocyte source. This shortage of human hepatocyte source is expected to be resolved by virtue of rapid progressing stem cell technologies. The second application is biological components of bioartificial liver (BAL) system for acute liver failure patients. Due to the lack of functional activity of clinically studied BAL systems and difficulty of establishing a manufacturing system for ready-to-use, additional research activities are stagnated. The third utilization of hepatocytes is in vitro drug screening studies such as drug metabolism, transport, biliary excretion, and toxicity tests. If cell therapeutic treatments using hepatocytes are clinically valuable to some types of liver diseases, the demand for liver transplantation would be significantly diminished.

Artificial Liver Devices and Bioartificial Liver Systems: Current Status / 대한이식학회지

Acute liver failure is a rapidly progressive disease of the liver associated with high morbidity and mortality without liver transplantation. Although good survival after transplantation can be achieved, due to the disparity between patients awaiting transplantation and available organs, many patients die due to progression of the disease while waiting for a liver graft. To reduce the high morbidity and mortality associated with acute liver failure, attempts have been made during the last several decades to develop a temporary liver support system, such as artificial and bioartificial livers. The artificial liver is a non-biological device mainly aimed at the removal of accumulated toxins during liver failure, and the bioartificial liver is a biological device that has bioreactors containing living hepatocytes which provide both biotransformation and synthetic liver functions. There are currently 3 artificial livers available in the market that have been actively used in the clinical field, and 11 bioartificial livers that have been developed and have undergone clinical trials. In this article, we will discuss about the 3 artificial liver devices and 5 bioartificial liver systems that are the most advanced and have been widely evaluated clinically. Also, the characteristics and the preclinical data of the first bioartificial liver system developed in Korea that is currently under clinical investigation, will be discussed.

Rapid Isolation of Adipose Tissue-Derived Stem Cells by the Storage of Lipoaspirates

PURPOSE: This study examined a rapid isolation method decreasing the time and cost of the clinical application of adipose tissue-derived stem cells (ASCs). MATERIALS AND METHODS: Aliquots (10 g) of the lipoaspirates were stored at 4degrees C without supplying oxygen or nutrients. At the indicated time points, the yield of mononuclear cells was evaluated and the stem cell population was counted by colony forming unit-fibroblast assays. Cell surface markers, stem cell-related transcription factors, and differentiation potentials of ASCs were analyzed. RESULTS: When the lipoaspirates were stored at 4degrees C, the total yield of mononuclear cells decreased, but the stem cell population was enriched. These ASCs expressed CD44, CD73, CD90, CD105, and HLA-ABC but not CD14, CD31, CD34, CD45, CD117, CD133, and HLA-DR. The number of ASCs increased 1x1014 fold for 120 days. ASCs differentiated into osteoblasts, adipocytes, muscle cells, or neuronal cells. CONCLUSION: ASCs isolated from lipoaspirates and stored for 24 hours at 4degrees C have similar properties to ASCs isolated from fresh lipoaspirates. Our results suggest that ASCs can be isolated with high frequency by optimal storage at 4degrees C for 24 hours, and those ASCs are highly proliferative and multipotent, similar to ASCs isolated from fresh lipoaspirates. These ASCs can be useful for clinical application because they are time- and cost-efficient, and these cells maintain their stemness for a long time, like ASCs isolated from fresh lipoaspirates.