Long-term maintenance of human liver tissue by ex-vivo perfusion of liver sections

Introduction: We recently presented a perfusion system for human liver sections able to keep hepatic functionality for six hours and to reflect clinical parameters of patients in non-cirrhotic and cirrhotic tissue (1). Here we demonstrate the successful extension of the perfusion time for up to 24 hours.

Methods: The initial setup of the perfusion system was modified concerning medium composition, oxygen supply and pH adjustment. Hourly taken samples from the perfusate were analyzed for markers of general metabolism, hepatic synthesis capacity and liver cell damage.

Results: The crucial phase of the perfusion appeared at 7 to 8h when metabolism accelerated strongly and pO2, glucose concentration and pH decreased accordingly. By addition of dextran 60 and introducing an oxygenation loop into the system the GLDH-release as marker for severe cell damage was reduced from 852.2 to 3.1 U/l/g at 8h and from 331.9 to 88.5 U/l/g at 22h in two representative perfusion experiments. Furthermore, initial attempts for long-term runs had to be aborted earlier due to large amount of precipitates in the perfusate that led to high perfusion pressures or clogged tubing. This could be entirely avoided by adding of poloxamers to the medium.

Conclusion: The successful extension of the perfusion time for human liver sections establishes a basis to apply this system for long term studies of liver pathophysiology. This opens the experimental methodology to e.g. toxin-induced liver injury, and advances the field a small step towards a human-based artificial liver system for research purpose.

Reference:

[1] Schreiter T, Marquitan G, Darnell M, Sowa JP, Bröcker-Preuss M, Andersson TB, Baba HA, Furch M, Arteel GE, Mathé Z, Treckmann J, Gerken G, Gieseler RK, Canbay A. An ex vivo perfusion system emulating in vivo conditions in noncirrhotic and cirrhotic human liver. J Pharmacol Exp Ther. 2012 Sep;342(3):730 – 41