[Fabrication of scaffold with controlled porous structure and flow perfusion culture in vitro]

3D Scaffolds with controlled porous structure were designed and fabricated by utilizing CAD and rapid prototyping techniques. A flow perfusion bioreactor, which allowed exposure of the culture cells to low levels of mechanical stimulation by fluid flow-induced shear stress, was developed in our lab. The scaffolds were pre-designed and the negative images of the designs were used to build the molds on a stereolithography (SL) apparatus with epoxy resins. Calcium phosphate cement paste was cast into the molds. And after pyrolysis, the 3D scaffolds with controlled internal pore architectures were obtained. Rabbit osteoblasts were seeded in 3D porous scaffolds, cultured in the flow perfusion bioreactor with media flow rate set at 2 mL/min and 6-well plates. At 3, 7, and 14 days, scanning microscopic evaluation showed excellent growth on the surface of scaffolds and poor viability of cells within microchannels in static cultures. In flow perfusion bioreactor, there was greater cellularity throughout the scaffolds and abundant deposition of extracellular matrix. Cells were also seen throughout the internal microchannels of scaffolds. These results represent that better mass transport of oxygen and nutrient occurred in the flow perfusion bioreactor and cells distribution in 3D porous scaffolds was improved.