Survival and differentiation of porcine hepatocytes encapsulated by semiautomatic device and allotransplanted in large number without immunosuppression

Background/Aims: The aim of this study was to evaluate the survival and fun ctions of porcine hepatocytes transplanted in large quantities in the perit oneal cavity of allogeneic animals following semiautomatic encapsulation. Methods: Isolated porcine hepatocytes and a polymer solution composed of AN 69 were coextruded through a double lumen spinneret. Minitubes containing h epatocytes were transplanted in the peritoneal cavity of 12 pigs (4 x 10(9) cells/animal) in the absence of immunosuppressive therapy. Seven, 15, and 21 days after transplantation, minitubes was collected and processed for an alyses. The morphology was examined under light and electron microscopy. Al bumin synthesis was assessed by semi-quantitative reverse transcription-pol ymerase chain reaction. Cytochrome P450 3A (CYP3A) gene expression was anal yzed by Western blot and by testosterone 6-beta-hydroxylation assay. Results: The device allowed to encapsulate 55 x 10(6) hepatocytes/min. Hepa tocytes exhibited normal structural and ultrastructural features up to day 21. Albumin gene expression decreased progressively between days 0 and 21. The amount of CYP3A protein and 6-beta-hydroxylase activity were approximat ely 2-fold lower at days 7 and 15 than in freshly encapsulated hepatocytes, and further decreased thereafter. Conclusions: The preservation of hepatocyte functions during 1-2 weeks is e ncouraging for potential short-term use of such bioartificial liver in futu re clinical application. (C) 2001 European Association for the Study of the Liver. Published by Elsevier Science BN. All rights reserved.