Construction of engineered liver cancer tissues with multichannel collagen gel

Dialysis of collagen solution against phosphate buffer solution results in collagen gels with multichannel structures (multichannel collagen gel: MCCG). Recently, we constructed engineered bone tissues and engineered epithelial lumen-like tissues by seeding cells on the surface of MCCG. However, the method to culture cells in MCCG have not been established. Therefore, we developed the method to culture cells in MCCG in this study. We constructed the engineered liver cancer tissues (ELCTs) by injecting the cell suspension which consisted of HepG2 cells and acidic atellocollagen solution into the phosphate buffer solution. At the injection rate of 7.4 μL/s, a particle-like ELCT was formed. By contrast, a fiber-like ELCT was formed at the injection rate of 166.7 μL/s. The results showed that we can control the shape of ELCT by regulating the injection rate of cell suspension. HepG2 cells embedded in MCCG grew and expressed alubumin, suggesting that HepG2 cells remain functional. HepG2 cells mainly proliferated in the microchannels of MCCG, resulting in the complex tissue structure which reflects multichannel structure of MCCG. The result showed that the MCCG can be used as a template scaffold for constructing engineered tissues with complex hierarchical structures.