A method for the design of 3D scaffolds for high-density cell attachment and determination of optimum perfusion culture conditions

The application of in vitro cultured cells in tissue engineering or drug screening, aimed at complex soft tissues such as liver, requires in vivo physiological function of the cultured cells. For this purpose, the scaffold in which cells are cultured should provide a microenvironment similar to an in vivo one with a three-dimensional extracellular matrix, a high supply capacity of O2 and nutrients, and high cell density. In this paper, we propose a method to design (1) the geometry of the scaffold, with a surface/volume ratio optimized to allow high-density (5×107 cells/mL) cell culture and (2) culture conditions that will supply optimal quantities of oxygen and nutrients. CFD modeling of mass transport was used to determine the shear stress as well as O2 and glucose metabolism in the scaffold (20 mm width–35 mm length) for various flow rates. Validation of the model was done through comparison with flow resistance and micro-PIV experiments. CFD analysis showed the maximum metabolic rate densities for this scaffold are 6.04×10−3 mol/s/m3 for O2 at 0.71 mL/min and 1.91×10−2 mol/s/m3 for glucose at 0.35 mL/min.