Dynamic Fabrication of Tissue-Engineered Bone Substitutes Based on Derived Cancellous Bone Scaffold in a Spinner Flask Bioreactor System

The in vitro dynamic fabrications of tissue-engineered bones were performed to assess the advantages of human adipose-derived stem cells (hADSCs) combined with acellular cancellous bone scaffold coming from fresh pig femur in a spinner flask compared with traditional static culture. In this study, the bio-derived cancellous bone was regarded as a biomimetic scaffold, and its surface appearance was observed under scanning electron microscopy (SEM). Moreover, its modulus of elasticity and chemical composition were measured with universal testing machine (UTM) and infrared detector, respectively. hADSCs were inoculated into cancellous bone scaffold at a density of 1 x 10(6) cells/mL and cultured in spinner flask and T-flask with osteogenic medium (OM) for 2 weeks, respectively. Following to this, the osteogenic differentiation was qualitatively and quantitatively detected with alkaline phosphatase (ALP) kits, and the cell growth and viability were assayed using Live/Dead staining; cell adhesion and extracellular matrix secretion were observed under a SEM. The average pore size of cancellous bone scaffold was 284.5 +/- 83.62 mu m, the elasticity modulus was 41.27 +/- 15.63 MPa, and it also showed excellent biocompatibility. The hADSCs with multidifferentiation potentials were well proliferated, could grow to 90 % fusion within 5 days, and were therefore suitable to use as seed cells in the construction of tissue-engineered bones. After 2 weeks of fabrication, cells were well-distributed on scaffolds, and these scaffolds still remained intact. Compared to static environment, the ALP expression, cell distribution, and extracellular matrix secretion on cancellous bones in spinner flask were much better. It confirmed that three-dimensional dynamic culture in spinner flask promoted ADSC osteogenic differentiation, proliferation, and matrix secretion significantly to make for the fabrication of engineered bone substitutes.