Cultivation of immortalized human hepatocytes HepZ on macroporous CultiSpher G microcarriers

• Published in: Biotechnology and bioengineering 2000-04, Vol.68 (1), p.59-70
• Main Authors: Werner, Andreas, Duvar, Sevim, Müthing, Johannes, Büntemeyer, Heino, Lünsdorf, Heinrich, Strauss, Michael, Lehmann, Jürgen
• Format: Article
• Language: English
• Subjects: amino acid metabolism; Amino acids; Amino Acids, Branched-Chain - metabolism; Anesthetics, Local - pharmacokinetics; Animal cells; Artificial organs; bioartificial liver; Biological and medical sciences; Bioreactors; Biotechnology; Biotransformation; Cell Culture Techniques - methods; Cell Division - drug effects; Cell Division - physiology; cell line; Cell Line, Transformed - enzymology; Cell Line, Transformed - ultrastructure; Cold Temperature; Culture Media - pharmacology; Enzymes; Establishment of new cell lines, improvement of cultural methods, mass cultures; Eukaryotic cell cultures; Fundamental and applied biological sciences. Psychology; Growth kinetics; Humans; Hypothermia; immortalized hepatocytes; L-Lactate Dehydrogenase - metabolism; Lidocaine - analogs & derivatives; Lidocaine - metabolism; Lidocaine - pharmacokinetics; Liver - cytology; Liver - metabolism; Liver, Artificial; Metabolism; Methods. Procedures. Technologies; Microscopy, Electron; Microscopy, Electron, Scanning; Microspheres; oxygen consumption; Oxygen Consumption - physiology; Phenylalanine - metabolism; spinner cultivation; stirred bioreactor; Tyrosine - metabolism
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/(SICI)1097-0290(20000405)68:1<59::AID-BIT7>3.0.CO;2-N

Cultivation of the new immortalized hepatocyte cell line HepZ was performed with a 1:1 mixture of DMEM and Ham's F12 media containing 5% FCS. The cells were grown in their 40th passage in 100 mL and 1 L volumes in spinner flasks and in a bioreactor, respectively. For the production of adherently growing HepZ cells macroporous CultiSpher G gelatin microcarriers were used in various concentrations from 1 to 3 g/L. The cells were seeded in a density of 2 × 105 cells/mL when using a microcarrier concentration of 1 g/L and 5 × 105 cells/mL at a microcarrier concentration of 3 g/L. After 7 days of cultivation a maximum cell concentration of 4.5 × 106 cells/mL was obtained in the spinner culture using a microcarrier concentration of 1 g/L. With bubble‐free aeration and daily medium exchange from day 7, 7.1 × 106 cells/mL were achieved in the bioreactor using a microcarrier concentration of 3 g/L. The cells exhibited a maximum specific growth rate of 0.84 per day in the spinner system and 1.0 per day in the bioreactor, respectively. During the growth phase the lactate dehydrogenase (LDH) activity rose slightly up to values of 200 U/L. At the end of cultivation the macroporous carriers were completely filled with cells exhibiting a spherical morphology whereas the hepatocytes on the outer surface were flat‐shaped. Concerning their metabolic activity the cells predominantly consumed glutamine and glucose. During the growth phase lactate was produced up to 19.3 mM in the spinner culture and up to 9.1 mM in the bioreactor. Maximal oxygen consumption was 1950 nmol/(106 cells·day). HepZ cells resisted a 4‐day long chilling period at 9.5°C. The cytochrome P450 system was challenged with a pulse of 7 μg/mL lidocaine at a cell density of 4.5 × 106 cells/mL. Five ng/mL monoethylglycinexylidide (MEGX) was generated within 1 day without phenobarbital induction compared to 26 ng/mL after a preceded three day induction period with 50 μg/mL of phenobarbital indicating hepatic potency. Thus, the new immortalized HepZ cell line, exhibiting primary metabolic functions and appropriate for a mass cell cultivation, suggests its application for a bioartificial liver support system. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 68: 59–70, 2000.