Bulletin of Experimental Biology and Medicine, Vol. 129, No. 6, June, 2000 595 NEW BIOMEDICAL TECHNOLOGIES Functional Activity of Hepatocytes in Tissue Fragments in a New Bioreactor Biological Artificial Liver V. V. Solov'ev, V. S. Akatov, and E. I. Lezhnev Translated from Byulleten' Eksperimental 'noi Biologii i Meditsiny, Vol. 129, No. 6, pp. 698-700, June, 2000 Original article submitted February 18, 2000 Functional activity of hepatocytes in a new bioreactor designed for culturing of liver tissue fragments under perfusion conditions was tested. Specific hepatic functions such as ammo- nium detoxification, urea and protein synthesis, and P-450-dependent metabolism of p-ni- troanisole were maintained for 1-1.5 days. The bioreactor can be used as a bioartificial liver support apparatus. Key Words: acute liver insujficiency; bioartificial liver support; bioreactor; hepatocytes, liver fragments The systems aimed at compensation of hepatic func- tions during liver failure are now developed and ap- plied in clinical practice [1,7,10,11]. These systems contain biologically active donor hepatocytes placed into a bioreactor, through which patient's blood or plasma is perfused. It is assumed that under these con- ditions hepatocytes execute tissue-specific functions and probably stimulate regenerative process in pa- tient's liver [1,11]. The efficiency of these systems in acute liver failure caused by inherited metabolic dis- eases was previously demonstrated [1,7,11]. Neverthe- less, the system, which could be widely used in clini- cal practice has not yet been created. Isolated hepatocytes are used in most proposed artificial liver support systems. Long-term mainte- nance of their functional activity requires immobiliza- tion, creation of an artificial extracellular matrix, or formation of spheroid hepatocyte aggregates [10,11 ]. An alternative approach is the use of tissue fragments or sections [9,12]. Preparation of liver fragments is a technologically simple process. It requires no expen- Laboratory of Cytotechnology, Institute of Theoretical and Experimen- tal Biophysics, Russian Academy of Sciences; Pushchino. Address for correspondence: soloval@mafl.ru. Solov'ev V. V. sive enzymes and media [8] and preserve natural ex- tracellular matrix maintaining high functional activity of hepatocytes [6]. Previously we studies biochemical activity of hepatocytes in cultured liver fragments, determined their optimal size, and demonstrated high functional activity of hepatocytes in this system [3]. However, liver tissue fragments cannot be used in most available bioreactors. Here we developed a new bioreactor for culturing of liver tissue fragments un- der perfusion conditions and at cell concentrations close to that in the liver tissue. The aim of this work was to investigate functional activity of hepatocytes in the new bioreactor and to evaluate the possibility of using this bioreactor as a bioartificial liver support apparatus. MATERIALS AND METHODS Williams-E medium containing 10 s M insulin, 10 " M dexamethasone, 50 rag/liter gentamicin, agarose, 13- glucuronidase (Sigma), and p-nitroanisole (PNA, Al- drich) were used. Wistar rats weighing 100'150 g were narcotized with ether, the liver was removed, placed in cold (4"C) Hanks' solution, and 10-15 min later minced to 0.5• 0007- 4888/00/0006-595525.00 9 Kluwer Academic/Plenum Publishers