Published online Jun 14, 2014. doi: 10.3748/wjg.v20.i22.6869
Revised: February 26, 2014
Accepted: March 6, 2014
Published online: June 14, 2014
AIM: To construct and evaluate the functionality of a choanoid-fluidized bed bioreactor (CFBB) based on microencapsulated immortalized human hepatocytes.
METHODS: Encapsulated hepatocytes were placed in the constructed CFBB and circulated through Dulbecco’s Modified Eagle’s Medium (DMEM) for 12 h, and then through exchanged plasma for 6 h, and compared with encapsulated cells cultivated under static conditions in a spinner flask. Levels of alanine aminotransferase (ALT) and albumin were used to evaluate the CFBB during media circulation, whereas levels of ALT, total bilirubin (TBil), and albumin were used to evaluate it during plasma circulation. Mass transfer and hepatocyte injury were evaluated by comparing the results from the two experimental conditions. In addition, the viability and microstructure of encapsulated cells were observed in the different environments.
RESULTS: The bioartificial liver model based on a CFBB was verified by in vitro experiments. The viability of encapsulated cells accounting for 84.6% ± 3.7% in CFBB plasma perfusion was higher than the 74.8% ± 3.1% in the static culture group (P < 0.05) after 6 h. ALT release from cells was 29 ± 3.5 U/L vs 40.6 ± 3.2 U/L at 12 h (P < 0.01) in the CFBB medium circulation and static medium culture groups, respectively. Albumin secretion from cells was 234.2 ± 27.8 μg/1 × 107 cells vs 167.8 ± 29.3 μg/1 × 107 cells at 6 h (P < 0.01), 274.4 ± 34.6 μg/1 × 107 cells vs 208.4 ± 49.3 μg/1 × 107 cells (P < 0.05) at 12 h, in the two medium circulation/culture groups, respectively. Furthermore, ALT and TBil levels were 172.3 ± 24.1 U/L vs 236.3 ± 21.5 U/L (P < 0.05), 240.1 ± 23.9 μmol/L vs 241.9 ± 31.4 μmol/L (P > 0.05) at 6 h in the CFBB plasma perfusion and static plasma culture groups, respectively. There was no significant difference in albumin concentration between the two experimental plasma groups at any time point. The microstructure of the encapsulated hepatocytes remained healthier in the CFBB group compared with the static culture group after 6 h of plasma perfusion.
CONCLUSION: The CFBB can function as a bioartificial liver based on a bioreactor. The efficacy of this novel bioreactor is promising for the study of liver failure.
Core tip: We constructed a novel choanoid fluidized bed bioreactor (CFBB) and received a national invention patent. We evaluated the CFBB functionality based on microencapsulated immortalized human hepatocytes. For this purpose, we placed the cultured hepatocytes into the CFBB and circulated through Dulbecco’s Modified Eagle’s Medium media for 12 h and through exchanged plasma for 6 h. The bioartificial liver based on a fluidized-bed bioreactor with microencapsulated immortalized human hepatocytes appeared to be effective for improving severe hepatitis plasma parameters. The efficacy of this novel bioreactor is promising for the study of liver failure.