Culture and expansion of mesenchymal stem cells in air-lift loop hollow fiber membrane bioreactor
Li XQ., Liu TQ., Zhu L., Song KD., Ma XH., Cui ZF.
Mesenchymal stem cells (MSCs), having the potential of multi-differentiation, are the promising "seed cells" in tissue engineering and ideal target cells in gene therapy. However, MSCs are in small quantity in bone marrow and are needed to be expanded in vitro to meet clinical need. In this paper, MSCs of passage 4 (P4) mixed with typeIcollagen were inoculated into hollow fiber membranes (HFMs), which formed gel under the conditions of 37°C, 5% CO2 and saturated humidity for 1 h and then were inoculated into an air-lift loop bioreactor (ALB) to culture and expand MSCs in three dimensions. During the experiments, the OD value of medium culturing MSCs in HFMs was detected every 24 h to calculate the cell number and to obtain the cell growth curves, and the metabolic parameters were also detected. Moreover, the expanded cells were identified with flow cytometer and through inducing them to multi-differentiate. The results show that the air-lift loop hollow fiber membrane bioreactor (ALHFMB) can keep O2 concentration almost constant. MSCs metabolize robustly and expand nearly 16 fold in the bioreactor after 7 d. And the expanded cells still maintain MSCs phenotypes and have the multi-differentiation potential of becoming bone, cartilage and adipose.