Osteoblastic cell proliferation with uniform distribution in a large scaffold using radial-flow bioreactor

Bioreactors employing different types of in vitro physiological cell stimulation have been developed to obtain three-dimensional cultivation for tissue engineering. The aim of this study was to determine whether osteoblastic cells proliferated uniformly over a large scaffold with a diameter of 18 mm and height of 10 mm under dynamic cultivation with the radial-flow bioreactor (RFB), and thereby ascertain the potential of this system in the regeneration of jaw bone. Mouse osteoblastic cells (MC3T3-E1) were seeded onto type 1 collagen sheets. Cells were then incubated outside the reactor for 6 h to produce precultured sheets. The six precultured sheets were then placed in the RFB to fabricate the scaffolds. Cells were dynamically cultured for 1 week at 37°C, pH 7.4, dissolved oxygen 6.86 ppm, and with the culture medium circulating at 3 mL/min. As a control, static cultivation cultured in the same manner without the circulating culture medium and single cultivation in a culture dish were performed. The resulting cell proliferation and cell distribution were analyzed. After 1 week of dynamic cultivation, cells showed a fivefold and fourfold increase with uniform distribution throughout the three-dimensional scaffolds than those under the static and single cultivation as a control, respectively. These results indicate that the RFB is a promising system for three-dimensional cultivation of osteoblastic cells for treating large bone defects by tissue engineering.