Prediction of permeability and fluid flow-induced wall shear stress in bone scaffolds with lattice architecture based on scaling down method

Nowadays, one of the most considerable topics studied in the field of bone tissue engineering is the design and construction of artificial scaffolds for the migration and growth of bone cells. These scaffolds must be manufactured in such a way that they can have properties similar to natural human bone tissue. Important properties of scaffolds include permeability and Wall Shear Stress (WSS) distribution in the porous space within the scaffolds. The present study aimed to explore the relationship between scaling down the size of the unit cell and the properties mentioned above. To achieve this goal, three spherical, cylindrical, and cubic geometries were used, and the structures were made smaller by using the scaling down method to prepare models with different unit cell sizes. The amount of permeability and average wall shear stress were calculated employing computational fluid dynamics (CFD) simulation. By examining the results, the permeability and WSS prediction functions were estimated. Finally, by comparing the results obtained from the simulation with the range of natural human bone tissue, two models with more suitable properties for the scaffold were proposed. The results of this simulation study can reduce trial and error costs to find a suitable scaffold design for additive manufacturing.