Fluid Permeability of Graded Porosity Scaffolds Architectured with Minimal Surfaces

Abstract

The natural local porosity variation in the native tissue can be replicated by graded porosity scaffolds. Scaffolds with radial porosity distribution can be a solution to improve both mechanical and biological functions of the biomimetic scaffolds. In the present study, fluid permeability as a quantitative indicator of biological performance is studied numerically and experimentally for different pore shapes and porosity distribution patterns in the scaffolds designed on the basis of triply periodic minimal surfaces (TPMSs). Among the uniform porosity scaffolds, those designed on the basis of P* (P surface) and Y** (G surface) showed the highest permeability. In the radially graded porosity scaffolds with linear porosity distribution, permeability was found to be about twice more sensitive to the peripheral porosity than the porosity at the center. The results suggest that the permeability-gradient parameter relationships can follow different trends depending on the pore shape as opposed to the conventional uniform porosity scaffolds. This implies the need for the design maps that were developed to choose appropriate scaffold pore design parameters. Finally, experimental permeability measurement was performed via a constant head permeability test, and the effect of test parameters (i.e., fluid height) was discussed.

Challenges in computational fluid dynamics applications for bone tissue engineering

“…Zhianmanesh et al . [47] analysed the permeability of cylindrical TPMS scaffolds with radially graded porosity. Their study indicates that although both the central and peripheral porosity have a considerable impact on structural permeability, the permeability is much more dependent on the peripheral porosity.…”

“…Most of the studies discussed in this review develop their numerical simulations by using CFD parameters taken from the literature (such as inlet velocity and fluid viscosity), or by validating their new numerical models by comparing the results with values from existing research. However, some papers validated their numerical results by comparing the computational results with values obtained through experimental testing [24,25,43,47,56,61].…”

Scalable3D‐printed lattices for pressure control in fluid applications

“…Unlike their stochastic counterparts, lattices can be designed with defined dimensions in an ordered arrangement. However, while additively manufactured lattices and periodic structures have been explored in detail for their mechanical and thermal properties, their use in fluid applications remains a high‐potential area 16–22 . Much of the recent investigation into lattices for fluid applications have emerged from studies of open‐cell foams.…”

The Variability in Cytocompatibility and Bone Conduction Based on Different Pore Size and Porosity of n-HA/PA66 Composite Scaffolds

“…The mechanical properties of the ideal bone scaffold material should match the host cortical bone, in which the compressive strength of cortical bone is 100-200 Mpa and the modulus of elasticity is 15-25 GPa, while the compressive strength of hydroxyapatite is about 120 MPa and the modulus of elasticity is 75-105 GPa, which can match the normal bone cortex (Li et al, 2021;Duan et al, 2020). In addition, pore size and scaffold architecture have to be controlled in order to provide the appropriate scaffold porosity, which encourages cellular activities inside the scaffold and allows nutrients, oxygen, and waste to transport conveniently into or out of the scaffold (Hui et al, 1996;Whang et al, 1999;Hutmacher, 2001;Itala et al, 2001;Ortiz and Jimeno, 2018;Ashrafi et al, 2019;Zhianmanesh et al, 2019). A good material structure can promote better mechanotransduction of cells.…”