Engraftment and function of intrasplenically transplanted cold stored rat hepatocytes

Hepatocellular transplant may potentially be efficacious for the treatment of selected liver metabolic disorders and acute hepatic failure. On the other hand, the use of hepatocyte cold preservation techniques in these transplantation protocols would allow to have available cells at the right time and place and, consequently, make an optimal use of scarce human hepatocytes. In our experiments we evaluated the biodistribution and functionality of cold preserved hepatocytes transplanted in the spleen of syngeneic rats. Isolated hepatocytes were labeled with the fluorescent dye 5(6)-carboxyfluorescein diacetate succinimidyl-ester, cold-preserved in modified University of Wisconsin (UW) solution for 48 or 96 h, and then transplanted into the spleen. Recipient animals were euthanized at 0 and 3 h, and at 1, 2, 3, 5, 10, and 14 days after transplantation for tissue analysis. Labeled hepatocytes were clearly identifiable in the recipient tissues up to 14 days later. Fluorescence microscopy also showed no significant differences in biodistribution when either cold stored or freshly isolated hepatocytes were transplanted. In addition, functional activity of transplanted cells was demonstrated by immunohistochemical detection of albumin at levels comparable to those found in normal hepatocytes. Our findings establish that cold preserved hepatocytes appear morphologically and biochemically normal after intrasplenic transplantation. Consequently, it indicates that modified UW solution makes it possible to safety preserve hepatocytes for up to 96 h before transplantation, perhaps providing sufficient time for hepatocyte allocation and potential recipient preparation, if applicable clinically.