Mechanical and biological properties of enhanced porous scaffolds based on triply periodic minimal surfaces

Abstract

Triply periodic minimal surfaces (TPMS) - based porous structures have been universally adopted for mimicking the properties of bone scaffolds due to their interconnected geometries with smooth surfaces and controllable pores. To further increase the versatility and controllability, an enhanced porous scaffold based on TPMS is proposed. The enhanced pores with different sizes are designed onto three types of TPMS-based scaffolds and then additively manufactured through laser powder bed fusion (LPBF). To investigate the manufacturability, various approaches are used and the results confirm that morphological features of printed samples are identical to the designed ones. As for mechanical properties, the results from the compression tests show that the elastic modulus and compressive strength of enhanced porous scaffolds are 2.0 GPa to 5.1 GPa and 86.7 MPa to 264.2 MPa respectively, which are all in the range of human bones. In terms of permeability, both experiments and simulation indicate that the designed scaffolds have 40%−150% improvement compared to scaffolds without enhanced pores. The biocompatibility of the scaffolds is further verified by in vitro studies. The results demonstrate the suitability of the proposed enhanced porous scaffolds for bone implants, and it will facilitate the design of more effective porous materials.

Keywords

• Enhanced porous scaffolds
• Triply periodic minimal surface
• Mechanical properties
• Permeability
• Biocompatibility