How do sinusoidal scaffolds affect fluid flow-induced wall shear stress and mass transport?

Bone is one of the most transplanted tissues. About 1.6 million bone grafts are performed each year only in the United States [1]. This treatment has serious drawbacks, such as a higher risk of infections or even donor site morbidities. Therefore, an alternative is the use of scaffolds to create bone tissue. The role of scaffolds in bone tissue engineering is to mimic the native bone tissue and is used to provide a template that supports seeded cells to get an optimal environment for their proliferation [2] to re-build the damaged structure. Hence, an optimal scaffold design is important and must be found because even small changes in the geometry of the pore network of the scaffold influences the process of cell growth and mechanical properties [2,3]. Wall shear stress (WSS) has a significant role in the differentiation of cells, especially for bone. Even minor changes in the flow field, especially near the wall regions, can directly affect cell bioactivity. Therefore, in this work, we use computational fluid dynamics (CFD) simulations to investigate the WSS and the effect of the flow rate on mass transport rates in scaffolds. The numerical results were compared to µ-particle image velocimetry (PIV) experiments to evaluate the reliability of the CFD method.