Niti minimal surface porous scaffolds matching human bone characteristics: mechanical, permeability and osteogenic properties

Advancements in additive manufacturing enable iterative development of complex porous implants, providing high-performance solutions for bone defect treatment. Investigating the relationships among materials, parametric design and performance is crucial for optimising implant efficacy. This study fabricated NiTi alloy-based minimal surface porous scaffolds (Diamond (D) and Gyroid (G)) via laser powder bed fusion. A combination of numerical simulation and experiments evaluated mechanical properties and permeability, while in vitro/in vivo tests explored effects of composition and structure on biocompatibility. Results showed D and G scaffolds had compressive strengths of 187.71 and 136.26 MPa, elastic moduli of 1.802 and 1.236 GPa, respectively. Falling-head tests showed that the permeability of the G scaffold (1.74 × 10−9 m2) was higher than that of the D scaffold (1.36 × 10−9 m2), and the fluid simulation results were consistent with the experimental trends. D scaffolds, with larger surface areas, enhanced cell attachment and adhesion, showing superior osteogenic efficacy. By regulating unit cell parameters, this study balanced high strength, low modulus, permeability and osteogenic performance, endowing NiTi scaffolds with broad orthopedic application prospects.