A perfusion bioreactor system. Schematic diagram of a perfusion bioreactor system design; (1) pressure data measurement and recording, (2) peristaltic pump, (3) media reservoir, (4) pulse dampener, (5) magnetic stir-plate, (6) whole organ bioreactor in media, (7) cell injection port, (8) cell culture incubator, and (9) system pressure probe. A total of 6 × 107 cells are injected into the culture media and perfused into the portal vein inlet of the acellular liver ECM scaffold. ECM, extracellular matrix.