Fig. 5

Integrated culture system combining in vitro tubular bile duct structure and primary hepatocyte tissue. a Seeding procedure for integrated tubular–hepatocyte culture. b Diagram showing hierarchy of integrated BEC-hepatocyte and tubular–hepatocyte culture established in collagen membrane-culture insert. c FDA assay administrated to hepatocyte-contained compartment. Fluorescein presented by green fluorescence accumulated in tubular bile duct structures located in the upper compartment. d Tubular structures demonstrated the ability to accumulate fluorescein. FDA removal is represented by yellow backlights. (n = 4; two independent experiments; values are the means ± SD; *P < 0.05; **P < 0.01). Red stars and bars indicate significant differences between independent treatments)