Fig. 1

Optimum condition for the establishment of tubular bile duct structure. a PDMS–plate treatment and seeding procedure for initial hierarchal co-culture. b Diagram showing cross-section of bile duct hierarchal co-culture after ECM overlay. c Map showing average % of bile duct-like structure surface area (mm²) in all cultures after ≤ 35 days (n = 12; three independent experiments). d Bile duct cysts and tubular bile duct structures. e Gene expression assay comparing bile duct cysts and tubular bile duct structure. Tubular bile duct structures highly expressed Ck19 marker but only weakly expressed hepatoblast (Afp) and hepatocyte (Alb) markers. β-actin was used as a housekeeping gene and primary cells served as a negative control (n = 5; three independent experiments, values are the means ± SD. *P < 0.05; **P < 0.01. Red stars and bars indicate significant differences between bile duct structures)