Irregular pore size of degradable bioceramic Voronoi scaffolds prepared by stereolithography: Osteogenesis and computational fluid dynamics analysis

A Voronoi method is a feasible approach for developing biomimetic trabecular scaffolds. This study used algorithms based on scaling factors to design Voronoi scaffolds (pore sizes 600–1200 μm). Scaffolds were prepared from β-tricalcium phosphate slurry and 3D printed using stereolithography. Characterization analysis revealed that the microporous structures were correctly processed. Computational fluid dynamics indicated that scaffold permeability increased and the specific surface area decreased with increasing pore size, and the wall shear stress was highest in P800 scaffolds (pore size-800 μm). In addition, MC3T3 cells were dynamically seeded and were more evenly distributed and showed higher proliferation and differentiation on the P800 scaffold than the other three scaffolds in vitro. For in vivo experiment, scaffolds were implanted into rabbit femur to analyze the degradation and osteogenesis. Histological and imaging examinations revealed that new bone formation was more abundant on the surface and inside of the P800 scaffold than the other three scaffolds, which was explained by the hydrodynamic response. This study optimized a controllable method for designing Voronoi scaffolds and indicated that the pore size distribution of the P800 scaffold (458.8–989.1 μm) is an optimal choice for trabecular scaffolds.