Evaluation of a hybrid artificial liver module based on a spheroid culture system of embryonic stem cell-derived hepatic cells.
Hybrid artificial liver (HAL) is an extracorporeal circulation system comprised of a bioreactor containing immobilized functional liver cells. It is expected to not only serve as a temporary liver function support system, but also to accelerate liver regeneration in recovery from hepatic  failure. One of the most difficult problems in developing a hybrid artificial liver is obtaining an adequate cell source. In this study, we attempt to differentiate embryonic stem (ES) cells by hepatic lineage using a polyurethane foam (PUF)/spheroid culture in which the cultured cells spontaneously  form spherical multicellular aggregates (spheroids) in the pores of the PUF. We also demonstrate the feasibility of the PUF-HAL system by comparing ES cells to primary hepatocytes in in vitro and ex vivo experiments. Mouse ES cells formed multicellular spheroids in the pores of PUF. ES cells  expressed liver-specific functions (ammonia removal and albumin secretion) after treatment with the differentiation-promoting agent, sodium butyrate (SB). We designed a PUF-HAL module comprised of a cylindrical PUF block with many medium-flow capillaries for hepatic differentiation of ES cells.  The PUF-HAL module cells expressed ammonia removal and albumin secretion functions after 2 weeks of SB culture. Because of high proliferative activity of ES cells and high cell density, the maximum expression level of albumin secretion function per unit volume of module was comparable to that  seen in primary mouse hepatocyte culture. In the animal experiments with rats, the PUF-HAL differentiating ES cells appeared to partially contribute to recovery from liver failure. This outcome indicates that the PUF module containing differentiating ES cells may be a useful biocomponent of  a hybrid artificial liver support system.
Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka, Japan.
Hiroshi
H
Mizumoto
Shunsuke
S
Hayashi
Kinya
K
Matsumoto
Kaoru
K
Ikeda
Tomoaki
T
Kusumi
Masakazu
M
Inamori
Kohji
K
Nakazawa
Hiroyuki
H
Ijima
Kazumori
K
Funatsu
Toshihisa
T
Kajiwara
D000641:Ammonia / Q000378:metabolism; D000818:Animals; D002087:Butyrates / Q000494:pharmacology; D002449:Cell Aggregation / Q000187:drug effects; D018929:Cell Culture Techniques / Q000295:instrumentation / Q000379:methods*; D002454:Cell Differentiation / Q000187:drug effects; D053595:Embryonic Stem Cells / Q000166:cytology*; D022781:Hepatocytes / Q000166:cytology* / Q000378:metabolism; D019164:Liver, Artificial; D051379:Mice; D008810:Mice, Inbred C57BL; D011140:Polyurethanes / Q000737:chemistry; D012709:Serum Albumin / Q000378:metabolism; D018874:Spheroids, Cellular / Q000166:cytology* / Q000473:pathology
D002087:Butyrates; D011140:Polyurethanes; D012709:Serum Albumin; D000641:Ammonia