Enhancing angiogenesis and osseointegration through a double gyroid Ti6Al4V scaffold with triply periodic minimal surface

The pore structure of porous scaffolds plays a crucial role in bone repair. The prevalent bone implant structure in clinical practice is the traditional cubic structure. However, the traditional cubic structure exhibits sharp edges and junctions that are not conducive to cell adhesion or growth. In this study, a double gyroid (DG) Ti6Al4V scaffold based on a triply periodic minimal surface (TPMS) structure was devised, and the osseointegration performance of DG structural scaffolds with varying porosities was investigated. Compression tests revealed that the elastic modulus and compressive strength of DG structural scaffolds were sufficient for orthopedic implants. In vitro cellular experiments demonstrated that the DG structure significantly enhanced cell proliferation, vascularization, and osteogenic differentiation compared to the cubic structure. The DG structure with 55% porosity exhibited the most favorable outcomes. In vivo experiments in rabbits further demonstrated that DG scaffolds could promote neovascularization and bone regeneration and maturation; those with 55% porosity performed best. Comparing the surface area, specific surface area per unit volume, and internal flow distribution characteristics of gyroid and DG structure scaffolds, the latter are more conducive to cell adhesion and growth within scaffolds. This study underscored the potential of DG scaffolds based on the TPMS structure in optimizing the pore structure design of titanium scaffolds, inducing angiogenesis, and advancing the clinical application of titanium scaffolds for repairing bone defects.