Biomimetic design and fabrication of porous chitosan–gelatin liver scaffolds with hierarchical channel network.

The presence of a hierarchical channel network in tissue engineering scaffold is essential to construct metabolically demanding liver tissue with thick and complex structures. In this research, chitosan–gelatin (C/G) scaffolds with fine three-dimensional channels were fabricated using indirect solid freeform fabrication and freeze-drying techniques. Fabrication processes were studied to create predesigned hierarchical channel network inside C/G scaffolds and achieve desired porous structure. Static in-vitro cell culture test showed that HepG2 cells attached on both micro-pores and micro-channels in C/G scaffolds successfully. HepG2 proliferated at much higher rates on C/G scaffolds with channel network, compared with those without channels. This approach demonstrated a promising way to engineer liver scaffolds with hierarchical channel network, and may lead to the development of thick and complex liver tissue equivalent in the future.