Editorial
Copyright ©2010 Baishideng. All rights reserved.
World J Gastroenterol. Jan 7, 2010; 16(1): 1-14
Published online Jan 7, 2010. doi: 10.3748/wjg.v16.i1.1
Hepatocyte cryopreservation: Is it time to change the strategy?
Xavier Stéphenne, Mustapha Najimi, Etienne M Sokal
Xavier Stéphenne, Mustapha Najimi, Etienne M Sokal, Catholic University of Louvain and St Luc Clinics, Paediatric Department (HPED), PEDI unit, Laboratory of Paediatric Hepatology and Cell Therapy, Hippocrate Avenue 10, 1200 Brussels, Belgium
Author contributions: All authors contributed to the writing and correction of the manuscript.
Supported by The Belgian National Fund for Medical Research, the Région Wallonne-DGTRE (Grant WALEO/HEPATERA) and “La Fondation St Luc - ARC Thérapie Cellulaire”; Stéphenne X is recipient of a Grant-FNRS for cell cryopreservation
Correspondence to: Etienne M Sokal, MD, PhD, Professor, Catholic University of Louvain and St Luc Clinics, Paediatric Department (HPED), PEDI unit, Laboratory of Paediatric Hepatology and Cell Therapy, Hippocrate Avenue 10, B-1200 Bruxelles, Belgium. etienne.sokal@uclouvain.be
Telephone: +32-2-7641387 Fax: +32-2-7648909
Received: October 10, 2009
Revised: November 18, 2009
Accepted: November 25, 2009
Published online: January 7, 2010
Abstract

Liver cell transplantation presents clinical benefit in patients with inborn errors of metabolism as an alternative, or at least as a bridge, to orthotopic liver transplantation. The success of such a therapeutic approach remains limited by the quality of the transplanted cells. Cryopreservation remains the best option for long-term storage of hepatocytes, providing a permanent and sufficient cell supply. However, isolated adult hepatocytes are poorly resistant to such a process, with a significant alteration both at the morphological and functional levels. Hence, the aim of the current review is to discuss the state of the art regarding widely-used hepatocyte cryopreservation protocols, as well as the assays performed to analyse the post-thawing cell quality both in vitro and in vivo. The majority of studies agree upon the poor quality and efficiency of cryopreserved/thawed hepatocytes as compared to freshly isolated hepatocytes. Intracellular ice formation or exposure to hyperosmotic solutions remains the main phenomenon of cryopreservation process, and its effects on cell quality and cell death induction will be discussed. The increased knowledge and understanding of the cryopreservation process will lead to research strategies to improve the viability and the quality of the cell suspensions after thawing. Such strategies, such as vitrification, will be discussed with respect to their potential to significantly improve the quality of cell suspensions dedicated to liver cell-based therapies.

Keywords: Hepatocyte; Cryopreservation; Quality; Mitochondria; Intracellular ice formation