Evaluation of the effective diffusivity of a freeform fabricated scaffold using computational simulation.

In scaffold-based tissue engineering, sufficient oxygen and nutrientsupply into cells within a scaffold is essential to increase cell viabil-ity and the proliferation rate. Generally, oxygen and nutrients reachthe cells through the media by diffusion in vitro or in vivo, assumingthere is no convection flow through a scaffold with small-sizedpores. The scaffold diffusion rate depends mainly on the scaffoldpore architecture. Thus, understanding the effect of scaffold porearchitecture on the diffusion mechanism is necessary to design anefficient scaffold model. This study proposes a computationalmethod to estimate diffusivity using the finite element analysis(FEA). This method can be applied to evaluate and analyze theeffective diffusivity of a freeform fabricated 3D scaffold. The diffu-sion application module of commercial FEA software was used tocalculate the spatial oxygen concentration gradient in a scaffoldmodel medium. The effective diffusivities of each scaffold could becalculated from the oxygen concentration data, which revealed thatthe scaffold pore architecture influences its effective diffusivity. Theproposed method has been verified experimentally and can beapplied to design pore architectures with efficient diffusion byincreasing our understanding of how the diffusion rate within a scaf-foldisaffected by its pore architecture. [DOI: 10.1115/1.4024570]Keywords: scaffold, mass transport, effective diffusivity,computational simulation, tissue engineering