Higher efficiency of retrovirus transduction in the late stage of primary culture of hepatocytes from nontreated than from partially hepatectomized rat

Three-Dimensional In Vitro Hepatic Constructs Formed Using Combinatorial Tapered Stencil for Cluster Culture (TASCL) Device

Attempts to create artificial liver tissue from various cells have been reported as an alternative method for liver transplantation and pharmaceutical testing. In the construction of artificial liver tissue, the selection of the cell source is the most important factor. However, if an appropriate environment (in vitro/in vivo) cannot be provided for various cells, it is not possible to obtain artificial liver tissue with the desired function. Therefore, we focused on the in vitro environment and produced liver tissues using MEMS technology. In the present study, we report a combinatorial TASCL device to prepare 3D cell constructs in vitro. The TASCL device was fabricated with an overall size of 10 mm × 10 mm with microwells and a top aperture (400 µm × 400 µm, 600 µm × 600 µm, 800 µm × 800 µm) and bottom aperture (40 µm × 40 µm, 80 µm × 80 µm, 160 µm × 160 µm) per microwell. The TASCL device can be easily installed on various culture dishes with tweezers. Using plastic dishes as the bottom surface of the combinatorial TASCL device, 3D hepatocyte constructs of uniform sizes (about ɸ 100 μm-ɸ 200 μm) were produced by increasing the seeding cell density of primary mouse hepatocytes. The 3D hepatocyte constructs obtained using the TASCL device were alive and secreted albumin. On the other hand, partially adhered primary mouse hepatocytes exhibited a cobblestone morphology on the collagen-coated bottom of the individual microwells using the combinatorial TASCL device. By changing the bottom substrate of the TASCL device, the culture environment of the cell constructs was easily changed to a 3D environment. The combinatorial TASCL device described in this report can be used quickly and simply. This device will be useful for preparing hepatocyte constructs for application in drug screening and cell medicine.

Portocaval shunt for hepatocyte package: challenging application of small intestinal graft in animal models

In developing therapeutic alternatives to liver transplantation, we have used the strategy of applying a small intestinal segment as a scaffold for hepatocyte transplantation and also as a portocaval shunt (PCS) system to address both liver dysfunction and portal hypertension. The aim of this study was to investigate the feasibility of such an intestinal segment in animal models. Hepatocytes isolated from luciferase-transgenic Lewis rats were transplanted into jejunal segments of wild-type Lewis rats with mucosa removal without PCS application. Luciferase-derived luminescence from transplanted hepatocytes was stably detected for 30 days. Then, we performed autologous hepatocyte transplantation into the submucosal layer of an isolated and vascularized small intestinal segment in pigs. Transplanted hepatocytes were isolated from the resected left-lateral lobe of the liver. On day 7, hepatocyte clusters and bile duct-like structures were observed histologically. To create an intestinal PCS system in pigs, an auto-graft of the segmental ileum and interposing vessel graft were anastomosed to the portal vein trunk and inferior vena cava. However, thrombi were observed in vessels of the intestinal PCSs. We measured the correlation between infusion pressure and flow volume in whole intestines ex vivo in both species and found that the high pressure corresponding to portal hypertension was still insufficient to maintain the patency of the intestinal grafts. In conclusion, we demonstrated the feasibility of the small intestine as a scaffold for hepatocyte transplantation in rat and pig models, but PCS using an intestinal graft failed to maintain patency in a pig model.