Effect of Fluid Properties on Bone Scaffold Permeability

Good permeability of the scaffold is critical to allow for inflow of cells, nutrients, as well as for waste product transfer. However, during designing the scaffold, the fluid properties of growth factor is always not being highlighted even though this component is one of fundamental is tissue engineering principles. Therefore, the purpose of this study is to determine the effects of fluid properties and viscosity on permeability of different 3D printed bone scaffold design. In this study, six 3D printed scaffold with different pore shape (circular and hexagonal) and different pore size (250 µm, 450µm and 650 µm) were designed by using Computer-aid Design software, SolidWorks. The scaffold design was simulated by using Computational Fluid Dynamic (CFD) simulation to analyze on how the fluid viscosity and inlet velocity affect permeability across the scaffold. The simulation results showed the hexagonal scaffold model encompassed more in the upper limit of natural bone permeability when compared to circular scaffold model. Moreover, based on analysis results, the favorable scaffold design was scaffold with hexagonal pore shape, pore size 650 µm and inlet velocity 0.0005 m/s since it has higher permeability value compared to circular scaffold. Hence, the permeability value of hexagonal scaffold was closer to the maximum value of natural bone permeability which is critical for successfulness of the long-term implant.