Three-dimensional in vitro cell culture leads to a marked upregulation of cell function in human hepatocyte cell lines--an important tool for the development of a bioartificial liver machine.

Upregulating hepatocyte function in proliferating human liver cell lines could provide cells for a bio-artificial liver. Ideally, a means of mimicking the biological extracellular matrix with a relatively inert, bio-compatible matrix is required. Alginate encapsulation of primary hepatocytes is biocompatible. This study aimed to characterize cells grown in a 3D configuration in alginate. A human-derived liver cell line encapsulated in 1% alginate was assessed for synthetic and detoxification functions. Secreted proteins measured (e.g., albumin, fibrinogen, alpha-1-antitrypsin etc.) were increased in alginate compared with monolayers. Cytochrome P450 1A1 activity increased three- to fourfold, whilst urea synthesis, undetectable in monolayer cultures, was synthesized by cells in alginate at levels approaching in vivo production. TEM revealed good ultrastructure reminiscent of normal hepatocytes. Alginate promotes 3D colonies of proliferating cells with upregulated liver functions. Rapid recovery of function of cryopreserved cells (< 18 h) provides added advantages for this system to support the biological component of an artificial liver for patients with fulminant hepatic failure.