The effect of bone scaffold gradient architecture design on stem cell mechanical modulation: a computational study

Scaffolds serve as a temporary mechanical support for the cells and transmit the mechanical stimuli to cells via their architectures. So, it can be considered that scaffold architecture design plays an important role in determination of stem cells fate. The gradient architecture scaffold provides a condition in which the cells experience various mechanical stimuli in different positions of the scaffold. These mechanical stimuli cause various signaling ways, which may result in various mechanical modulation effects such as cell differentiation that occur on the scaffold at the same time. In the present study, using computational fluid dynamics, the interactions between a bone scaffold with gradient pore size and fluid have been investigated. The scaffold has been modeled by a CAD software. The inlet velocities of 100, 50, 25, 10 and 1 μm.s^-1 were applied to the scaffold and different parameters such as hydrodynamic pressure, fluid shear stresses and shear rates have been evaluated. The results portrayed that the inlet velocity in the range of 50-100 μm.s^-1 may induce the critical stress magnitudes activating significant biological mechanisms on various positions of the gradient architecture scaffold. It may lead to activate various signaling pathways simultaneously and cause diverse differentiations and influence on the mesnchymal stem cell (MSC) fate.