Objective: To design a novel bioreactor of bioartificial liver system by using expanded and differentiated human bone marrow mesenchymal stem cells (hBMMSCs) as active cells.
Methods: hBMMSCs were isolated from bone marrow of volunteers and grown to 10(7) population, and then replanted into hollow fiber cartridge to expand continuously for 10 days. They were incubated in differentiation medium containing recombinant human hepatocyte growth factor (rhHGF), recombinant human fibroblast growth factor 4 (rhFGF-4), recombinant human oncostatin M (rhOSM), and the cells were induced to differentiate into hepatocyte-like cells for 21 days. The functions of the differentiated cells, such as synthesis of albumin (Alb), alpha fetoprotein (AFP) were determined. Eighteen days later, the functions of metabolism of ammonia and benzodiazepines, and synthesis of urea were monitored. The cellular synthesis rate of Alb was measured with flow cytometer. The glucose levels in the medium were measured during entire culture process.
Results: (1)Glucose-uptake in the cartridge was increased during the culture period, and at the end of culture, the number of cells in the cartridge increased to 10(9). (2)After induction, AFP was detected on day 6, reaching the peak level on day 12. Alb was detected on day 9. Eighteen days after being induced, the clearance rate of ammonia and benzodiazepines in the cartridge was 2.0-2.7 mmol/24 hours and 3.2-3.8 mg/24 hours, respectively, and urea production rate was 1.8-2.2 mmol/24 hours. (3)At the end of the culture, 66.18%-76.91% of the cells showed positive Alb expression.
Conclusion: hBMMSCs can be multiply to construct a novel bioreactor of bioartificial liver system in a hollow fiber cartridge.