Mechanical and Permeability Properties of Radial-Gradient Bone Scaffolds Developed by Voronoi Tessellation for Bone Tissue Engineering

Irregular bone scaffolds fabricated using the Voronoi tessellation method resemble the morphology and properties of human cancellous bones. This has become a prominent topic in bone tissue engineering research in recent years. However, studies on the radial-gradient design of irregular bionic scaffolds are limited. Therefore, this study aims to develop a radial-gradient structure similar to that of natural long bones, enhancing the development of bionic bone scaffolds. A novel gradient method was adopted to maintain constant porosity, control the seed site-specific distribution within the irregular porous structure, and vary the strut diameter to generate radial gradients. The irregular scaffolds were compared with four conventional scaffolds (cube, pillar BCC, vintiles, and diamond) in terms of permeability, stress concentration characteristics, and mechanical properties. The results indicate that the radial-gradient irregular porous structure boasts the widest permeability range and superior stress distribution compared to conventional scaffolds. With an elastic modulus of ranging from 4.20 to 22.96 GPa and a yield strength between 68.37 and 149.40 MPa, it meets bone implant performance requirements and demonstrates significant application potential.