Biomechanical properties of cylindrical and twisted triply periodic minimal surface scaffolds fabricated by laser powder bed fusion

In this study, novel TPMS-based scaffolds with twisted feature were rationally designed and additively manufactured using laser powder bed fusion (LPBF) for mimicking the properties of human bones. Experimental and computational analyses of their morphological features, manufacturability, mechanical properties, and permeability were conducted. It was found that the porosity, surface area, and deviation of the specimens were affected by the change of twist angle. In terms of mechanical properties, the manufactured scaffolds yielded favorable performance to provide ample mechanical support for bone tissue regeneration. The measured mechanical values were all in accordance with those of human bones. The results showed that the twist angle could affect the compressive response, leading to adjustable elastic modulus and compressive strength. It was also observed that the permeability of the twisted scaffolds was in the range of values reported for human bones. The experimental and computational results demonstrated the effects of the twist angle on the mass transport properties. In addition, in vitro studies were conducted for assessing the biocompatibility of the fabricated scaffolds. In summary, the developed twisted porous metallic scaffolds are shown as potential candidates to tailor the properties of bone-substituting biomaterials with tunability in terms of the topological, mechanical, and mass transport properties.