HUMAN LIVER CELLS IN A 3-D HIGH DENSITY FOUR-COMPARTMENT COCULTURE BIOREACTOR FOR A MODULAR EXTRACORPOREAL LIVER SUPPORT CONCEPT

Abstract

The development of a bioreactor providing a three-dimensional network of interwoven capillary membranes with integrated oxygenation enables the culture of primary human liver cells from discarded donor organs for extracorporeal liver support. Primary liver cells from n=104 discarded organs (donor age: 56+/− 13 years) were isolated and 2.8 to 6.4 x 1010 parenchymal hepatocytes (PC) were co-cultured with non-parenchymal cells (NPC) of the same organ in bioreactors (n=47). Some of the bioreactors were used clinically, utilizing a modular liver support technology including a detoxification and a dialysis module, after a stand-by period of 1–3 weeks in order to bridge patients with liver failure to Ltx (n=8). Cell metabolism was stable over a period of at least 2-3 weeks. By transmission electron microscopy (TEM) and immunohistochemistry it was demonstrated that PC and NPC spontaneously re-built tissue-like structures. Vascular cavities and bile-duct-like channels, both exhibiting proliferation activities (Ki-67 immunoreactivity [IR]), were regularly distributed. Some of the bile-duct-like channels showed ultrastructural similarities to the Canals of Hering found in the natural liver. Cells with morphological and antigenic characteristics of adult liver stem cells, i.e. CD 34 IR and c-kit IR, were regularly observed. The results indicate that primary human liver cells from transplant discards can be maintained in bioreactors and enable cell-based extracorporeal liver support therapy.