Entwicklung eines Hepatozytenbioreaktors zur Anwendung in der Toxikologie und Metabolismusforschung

New approaches for in vitro testing of hepato-mediated toxicity are
undertaken to offer alternatives to in vivo animal testing. The
described bioassay for hepato-mediated toxicity testing is based on
a small scale hepatocyte-bioreactor with pig hepatocytes connected
to a silicon sensor based microphysiometer system for monitoring of
the extracellular acidification rate (EAR) of cells and the
microphysiometer alone. EAR represents the metabolic activity of
tested cells (hepatocytes and ZR 751 cells) under the influence of
perfused media, compared to controls, which were set to 100%.
Cyclophosphamide (CYCL), whose cytostatic effect is dependent on
CYP 450 biotransformation was used as a model substrate. CYCL
showed decrease of EAR in hepatocytes, but not in ZR 751 cells.
Bioreactor supernatant including CYCL was pumped into the
microphysiometer and EARs of the target ZR 751 cell line were
recorded. After 7 h of bioreactor supernatant perfusion the ZR 751
cell line showed an EAR decrease of 18.68% +/- 10.18, as compared
to controls (bioreactor supernatant from the identical set-up
without CYCL). Thus the presented model of hepato-activated
toxicity showed an EAR decrease in the ZR 751 cell line that
reflected the toxic activation of CYCL by the bioreactor. This new
bioassay serves as an example of future applications for hepatocyte
bioreactors in automated toxicity testing devices, e.g. in
preclinical drug studies or evaluation of hepato-mediated toxicity,
not depending on cell destruction or further assays.