Combining Fluid Dynamics and Biological Experiments to Explore the More Suitable Porosity for Bone Inducing Porous Tantalum Scaffolds

OBJECTIVE: Repair of large bone defects remains a clinical challenge in orthopedics. Optimal porosity is pivotal for the osteogenic induction of porous tantalum scaffolds. This study aimed to investigate the appropriate porosity of porous tantalum scaffolds for osteogenic induction. METHODS: Porous tantalum scaffolds with approximately 45%, 55%, and 65% porosity were fabricated via parametric engineering and laser powder bed fusion 3D printing. Computational fluid dynamics simulations were used to analyze their hydrodynamic characteristics, and in vitro experiments were performed to evaluate their biocompatibility and osteogenic differentiation capacity. RESULTS: The porosity of scaffolds can influence the internal fluid microenvironment and further regulate the behavior of bone marrow mesenchymal stem cells. Compared to scaffolds with porosities of 45% and 65%, those with a porosity of approximately 55% exhibited optimal hydrodynamic properties, superior cellular compatibility, and outstanding osteogenic differentiation capacity, along with the highest mineralized nodule density and significantly elevated expression levels of osteogenesis-related genes (p < 0.001) and proteins (p < 0.01). CONCLUSION: This study confirms that approximately 55% porosity is more suitable for osteogenic induction in porous tantalum scaffolds. These findings provide theoretical and experimental evidence for subsequent in vivo studies and clinical translation of porous tantalum scaffolds.