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

Abstract

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.

TPMS Microarchitectures for Vertical Bone Augmentation and Osteoconduction: An In Vivo Study

“…This suggests that in terms of bone ingrowth and healing, a curvy microarchitecture, preferentially the G-gyroid or D-diamond, performs equally well as a strait lattice or grid microarchitecture. The mechanics and the lightweight features of TPMS microarchitectures are, however, superior to grid and lattice microarchitectures [ 16 , 35 ]. Taking into account that graft loss is one of the most frequent complications for vertical augmentation with bone blocks [ 36 ], the use of microarchitectures with the enhanced mechanical properties is beneficial.…”