Background: The use of primary human liver cells obtained from discarded donor organs is increasingly favored for cell-based extracorporeal liver support systems. However, as cryopreservation of primary human hepatocytes causes a significant loss of metabolic activity, the transport of bioreactors with viable liver cells is required. The aim of this study was to evaluate the impact of two major potential threats to viable cells during transport: temperature changes and mechanical stress.
Methods: In each experiment three hollow fiber-based bioreactors were charged with primary human liver cells originating from the same discarded donor organ and were simultaneously kept under culture conditions for 8 days. In total, 18 bioreactors were evaluated. On the fifth day the bioreactors were exposed to hypothermia (4 degrees C, n = 3), to hyperthermia (42 degrees C, n = 3), or served as normothermic controls (37 degrees C, n = 3). In a second test series bioreactors were exposed to vibration (21 Hz for 20 min, thereafter 7 Hz for 160 min, n = 3), or were operated as control cultures (n = 6). The release of hepatocyte-specific enzymes was determined as an indicator for cell damage.
Results: Hypothermic stress resulted in a significant release of transaminases and led to disturbances of the histological integrity, all indicating a high degree of cell damage. When compared with the control cultures, hyperthermia and mechanical stress in terms of vibration had no significant effect on the cells.
Conclusion: The transport of hollow fiber bioreactors charged with viable primary human liver cells appears to be feasible in transport monitors for perfusion and temperature control.