Distribution of Stresses within Scaffolds Used In Perfusion Bioreactors

Tissue engineering is an interdisciplinary field involving the replacement of damaged tissues or organs with artificial tissue substitutes. In bone tissue engineering, stem cells are typically seeded within 3-D scaffolds, made of synthetic biodegradable polymers, and followed by dynamic culture in perfusion bioreactors to reproduce tissue. Stresses that are generated by the flow of the culture media play an extremely important role in cell proliferation and cell differentiation. A recent study (Voronov R.S., Van Gordon S.B., Sikavitsas, V.I., Papavassiliou, D.V., Appl. Phys. Let., 2010, 97:024101) discovered that normalized flow-induced stresses inside high porosity and randomly structured scaffolds follow a common gamma probability density function. This  goal of the present study is to focus on the distribution of flow-induced stresses in scaffolds that can be obtained with lithography or other techniques and to further investigate whether a common distribution can describe the distribution of stresses in these kinds of structure. Different constructed scaffolds were created numerically and stresses induced by flow were obtained by solving the discrete Navier-Stokes equation. It was found that the stress distributions follow a common distribution within statistically acceptable accuracy, and that the direction of flow relative to the internal architecture of the porous scaffolds is an important factor that affects the stress distribution.