doi:10.1089/bio.2012.0015engSolanas, ESostres, CSerrablo, AGarcía-Gil, AAranguren, FJimenez, PSerrano, MT.Incubation with dimethyl sulfoxide prior to cryopreservation improves functionality of thawed human primary hepatocytesART-2012-92401Background: Efficient cryopreservation of human hepatocytes is essential for their use in cell therapy. This study investigated the effects of adding melatonin and/or dimethyl sulfoxide (DMSO) to pre-incubation and/or freezing solutions on the viability and function of thawed human hepatocytes. Methods: Isolated human hepatocytes were pre-incubated for 90 min at 4°C in Williams' Medium E (WEM), WEM containing 5 mM melatonin dissolved in DMSO, or WEM containing the equivalent amount of DMSO (1%). The hepatocytes were frozen in University of Wisconsin solution (UW) and 10% DMSO, with or without 5 mM melatonin. After thawing, viability, plating efficiency, mitochondrial dehydrogenase activity (MTT), and albumin and urea production were analyzed. Results: Viability and plating efficiency were not affected by melatonin or DMSO in pre-incubation media. Unexpectedly, hepatocytes pre-incubated with DMSO had significantly higher MTT (29.7% vs. control, p<0.01), albumin (82.8% vs. control, p<0.05), and urea amounts (26.2% vs. control, p=0.06) than those incubated only with WEM. Hepatocytes pre-incubated in media containing melatonin had amounts between those of cells incubated with DMSO or only with WEM (p<0.05 for MTT and p>0.05 for albumin and urea values). Also, the addition of melatonin to the freezing media did not significantly improve any of the studied parameters (p>0.05). Discussion: Adding 1% DMSO to pre-incubation media prior to the cryopreservation of human hepatocytes preserves hepatocyte function after thawing. These findings could be considered in current hepatocyte cryopreservation protocols.2012http://zaguan.unizar.es/record/13026310.1089/bio.2012.0015http://zaguan.unizar.es/record/130263oai:zaguan.unizar.es:130263BIOPRESERVATION AND BIOBANKING 10, 5 (2012), 446-53All rights reservedhttp://www.europeana.eu/rights/rr-f/info:eu-repo/semantics/closedAccess