TPMS-based scaffolds: Adaptation of morphological properties and mechanical response to reference tissue

Tissue engineering of bones is based on repair and replacement of their damaged parts with artificial scaffolds that have similar morphometric, mechanical, and biological properties. This study proposes a new approach to tailor the geometry and mechanical response of a scaffold to those of the micro-CT model of a reference bone tissue using target's morphometric parameters such as mean trabecular thickness and porosity. A design approach for scaffolds is based on triply periodic minimal surfaces (TPMS), adapted by adjusting their surface parameters, number and orientation of unit cells. A match of stresses distributions in a scaffold with that of the reference model under the same loading conditions was used for comparison of their mechanical responses. The effect of the TPMS-based unit-cell type on the morphometric properties of the structure is studied, and the mechanical behaviour of the structures under uniaxial compression and shear loading is numerically simulated. The results indicate that the spatial orientation of the unit cell significantly affects the mechanical response and stress intensity under different mechanical loads. Several TPMS structures were identified with a good agreement with the reference model in terms of mechanical response for the controlled morphometric parameters of porosity and mean wall thickness.