(206f) Engineering Of Functional Bile Ducts Using Immobilized Glycosaminoglycans
Cholangiocytes (bile duct epithelial cells) perform important biological functions in formation and transport of bile, as well as producing cytokines and chemokines. A fully functional tissue engineered liver requires a functional bile drainage system. Current liver tissue engineering efforts have paid less attention to the incorporation of structured biliary excretion into engineered liver designs. We propose to develop a bile duct scaffold for integration into an engineered liver system. The approach is based on the use of immobilized glycosaminoglycans (GAGs) to modulate cholangiocyte organization and function. Engineered bile ducts may be incorporated into hepatocyte scaffolds to achieve a functional bile duct network. In this study we investigated cholangiocyte behavior on tubular, GAG-derivatized chitosan scaffolds. Chitosan tubes produced via a dip-coating method were GAG-derivatized using carbodiimide chemistry. Cholangiocytes cultured on the tubes were monitored using phase contrast and fluorescence microscopy. Surface-dependent proliferation and organization of cholangiocytes on different GAGs was assessed by immunofluorescence microscopy, DNA assays and histology. Cholangiocyte-type epithelial polarity was evaluated by quantifying transport of rhodamine 123 from the basal side to the central lumen. Culture results showed that cholangiocytes proliferated on and coated GAG-chitosan tubes with variable efficiency. The engineered bile duct retained transport functions, and thus may be a useful adjunct in the design of an engineered liver system with functional bile ducts. Current work seeks to integrate the bile duct construct with three dimension hepatocyte cultures. Result of these integration studies will be reported.