Effect of Porosity and Pore Shape on the Mechanical and Biological Properties of Additively Manufactured Bone Scaffolds

This study investigates the effect of porosity and pore shape on the biological and mechanical behavior of additively manufactured scaffolds for bone tissue engineering (BTE). Polylactic acid scaffolds with varying porosity levels (15-78%) and pore shapes, including regular (rectangular pores), gyroid, and diamond (triply periodic minimal surfaces) structures, are fabricated by fused filament fabrication. Murine-derived macrophages and human bone marrow-derived mesenchymal stromal cells (hBMSCs) are seeded onto the scaffolds. The compressive behavior and surface morphology of the scaffolds are characterized. The results show that scaffolds with 15%, 30%, and 45% porosity display the highest rate of macrophage and hBMSC growth. Gyroid and diamond scaffolds exhibit a higher rate of macrophage proliferation, while diamond scaffolds exhibit a higher rate of hBMSC proliferation. Additionally, gyroid and diamond scaffolds exhibit better compressive behavior compared to regular scaffolds. Of particular note, diamond scaffolds have the highest compressive modulus and strength. Surface morphology characterization indicates that the surface roughness of diamond and gyroid scaffolds is greater than that of regular scaffolds at the same porosity level, which is beneficial for cell attachment and proliferation. This study provides valuable insights into porosity and pore shape selection for additively manufactured scaffolds in BTE. This study investigates the effect of porosity (15-78%) and pore shapes, such as triply periodic minimal surface, on the biological and mechanical behavior of additively manufactured bone scaffolds. The scaffolds are seeded with murine-derived macrophages and human bone marrow-derived mesenchymal stromal cells. The compressive behavior and surface morphology of the scaffolds are characterized.image

Automated summary

This study investigates the effect of porosity and pore shape on the biological and mechanical behavior of additively manufactured bone scaffolds with porosity levels ranging from 15% to 78% and different pore shapes including triply periodic minimal surfaces. The scaffolds were seeded with murine-derived macrophages and human bone marrow-derived mesenchymal stromal cells and the compressive behavior and surface morphology were characterized. The study found that scaffolds with 15%, 30%, and 45% porosity had the highest rate of cell growth and that gyroid and diamond scaffolds exhibited better compressive behavior compared to regular scaffolds. The study provides valuable insights for the selection of porosity and pore shape in additively manufactured bone scaffolds.