Fig. 1

The substance exchanger-based perfusion bioreactor system. a Photograph of this substance exchanger-based perfusion bioreactor. b A schematic of this novel bioreactor system. c Photograph of each unit of this perfusion bioreactor (1, medium reservoir; 2, substance exchanger; 3, peristaltic pump; 4-1, the first generation of the tissue culture chamber; 4-2, the second generation of the tissue culture chamber; 5, PO2, PCO2 and pH sensors)