Mass transfer in porous tissue engineering scaffolds

Abstract

Scope and Method of Study: This study evaluated the effects of both local and global scale mass transport phenomena through degradable porous polymer matrices typically used in tissue engineering. Analytical, computational and experimental methods were used to explore changes in matrix permeability as well as flow distribution, pressure drop, shear stress, and nutrient consumption when maturing matrices in vitro.

Findings and Conclusions: Nanoparticles fabricated from a variety of materials (Latex, PLGA, PLGA-HA, and chitosan) were successfully integrated into the porous matrices. Additionally, it was found that the permeability of the porous matric could be modified based on both the size and number of embedded particles. The flow dynamics in bioreactor systems containing porous polymer matrices were also evaluated. The residence time distribution for reactors with and without porous structures was evaluated computationally and validated experimentally. The shear stress and pressure drop profiles for the reactors were simulated to explore the effect of changes within the porous structure. Finally, the effects of cellular respiration were added into the simulation and attempts were made to visualize the oxygen profile experimentally. These results provide insight into the inner working of tissue regeneration and should lead to both improved scaffold designs and better clinical outcomes.