(129d) Effects of Cells On Local Fluid Stress within Nonwoven Fiber Mesh Bone Tissue Engineering Scaffolds Using Lattice Boltzmann Simulations of Flow through High Resolution Micro-CT Imaged Scaffolds

Stress caused by perfusion of cell culture media through a 3D porous bone tissue engineering scaffold is thought to be one of the major stimulating factors of cell differentiation and proliferation. Moreover, excessive amounts of stress can cause detachment or cell rupture. Although it is possible to calculate local stresses within an empty scaffold using computation, it remains a major challenge to be able to account for the presence of the cells and tissue. Hard tissue has been previously imaged in 3D for long term cultures, but imaging of soft tissue is still difficult largely due to technological limitations of the micro-CT machines and the small size of the cells seeded on the scaffold (approximately 20 microns in diameter).

In this study we use a combination of high resolution micro-CT (1.5 micron resolution) with high performance computing simulations in order to calculate how the presence of cells affects the fluid dynamic environment within the scaffolds under flow perfusion. During the cell culture period, the conditions inside the scaffold are transient, as the porosity and tortuosity inside it change due to the presence of cells and due to tissue growth. The fundamental understanding that can be potentially gained from this work can enable the optimization of scaffold structure (which currently is largely a trial-and-error process).