Slow cooling rate with a shock cooling program can effectively cryopreserve pig hepatocytes

Area of Science:

• Hepatology
• Cell Biology
• Cryobiology

Background:

• Hepatocyte transplantation offers a promising alternative to whole organ liver transplantation.
• A robust hepatocyte bank system is essential for the clinical application of hepatocyte transplantation.
• Developing effective cryopreservation protocols is key to establishing such a bank.

Purpose of the Study:

• To develop and optimize a cryopreservation protocol for porcine hepatocytes.
• To utilize controlled rate freezers (CRF) for cryopreserving hepatocytes for bioartificial liver systems.
• To assess the impact of cryopreservation on hepatocyte viability and function.

Main Methods:

• Porcine hepatocytes were isolated from juvenile pigs (3-4 weeks old).
• Spheroid hepatocytes were cryopreserved using University of Wisconsin (UW) solution and controlled rate freezing.
• Post-thaw assessment included viability, plating efficiency, urea synthesis, and ammonia removal.

Main Results:

• Cryopreservation significantly affected hepatocyte viability and specific functions.
• An optimal protocol achieved approximately 80% cell viability.
• This involved a -1°C/min slow cooling rate with shock cooling, UW solution, and 15% dimethyl sulfoxide (DMSO).

Conclusions:

• The developed cryopreservation method significantly improved hepatocyte preservation.
• This protocol is suitable for cryopreserving porcine hepatocytes for potential bioartificial liver applications.
• Further research is needed for large-scale cryopreservation and practical clinical implementation.