Integrated evaluation of biomechanical and biological properties of the biomimetic structural bone scaffold: Biomechanics, simulation analysis, and osteogenesis

Abstract

A porous structure is essential for bone implants because it increases the bone ingrowth space and improves mechanical and biological properties. The biomimetically designed porous Voronoi scaffold can reconstruct the structure and function of cancellous bone; however, its comprehensive properties need to be investigated further. In this study, algorithms based on scaling factors were used to design the Voronoi scaffolds. Classic approaches, such as computer-aided design and the implicit surface method, have been used to design Diamond, Gyroid, and I-WP scaffolds as controls. All scaffolds were prepared by selective laser melting of titanium alloys and three-dimensional printing. Mechanical tests, finite element analysis, and in vitro and in vivo experiments were performed to investigate the biomechanical, cytologic, and osteogenic performance of the scaffolds, while computational fluid dynamics simulations were used to explore the underlying mechanisms. Diamond scaffolds have a better loading capacity, and the mechanical behaviors and fluid flow of Voronoi scaffolds are similar to those of the human trabecular bone. Cells showed more proliferation and distribution on the Diamond and Voronoi scaffolds and exhibited evident differentiation on Gyroid and Voronoi scaffolds. Bone formation was apparent on the inner part of the Gyroid, the outer part of the I-WP, and the entire Diamond and Voronoi scaffolds. The hydrodynamic properties and stimulus response of cells influenced by the porous structure account for the varied biological performance of the scaffolds. The Voronoi scaffolds with bionic mechanical behavior and an appropriate hydrodynamic response exhibit evident cell growth and osteogenesis, making them preferable for porous structural bone implants.