3D-Printed PEEK/Silicon Nitride Scaffolds with a Triply Periodic Minimal Surface Structure for Spinal Fusion Implants

Abstract

The issue of spine-related disorders is a global healthcare concern that requires effective solutions to restore normal spine functioning. Spinal fusion implants have become a standard approach for this purpose, making it crucial to develop biomaterials and structures that possess high osteogenic capacities and exhibit mechanical properties and dynamic responses similar to those of the host bone. This study focused on the fabrication of 3D-printed polyether ether ketone/silicon nitride (PEEK/SiN) scaffolds with a triply periodic minimal surface (TPMS) structure, which offers several advantages, such as a large surface area and uniform stress distribution under load. The mechanical properties and dynamic response of PEEK/SiN scaffolds with varying porosities were evaluated through mechanical testing and finite element analysis. The scaffold with 30% porosity exhibited a compressive strength (34.56 ± 1.91 MPa) and elastic modulus (734 ± 64 MPa) similar to those of trabecular bone. In addition, the scaffold demonstrated favorable damping properties. The biological data revealed that incorporating silicon nitride into the PEEK scaffold stimulated osteogenic differentiation. In light of these findings, it can be inferred that PEEK/SiN TPMS scaffolds exhibit significant potential for use in bone tissue engineering and represent a promising option as candidates for spinal fusion implants.

Investigation of the Effectiveness of Silicon Nitride as a Reinforcement Agent for Polyethylene Terephthalate Glycol in Material Extrusion 3D Printing

“…In addition to its excellent mechanical properties as a ceramic material, Si 3 N 4 is considered a bioceramic that can be useful for medical or healthcare applications. It is a subject of interest in the field of biomedicine because of its biocompatibility and superior chemical, physical, and mechanical properties, which are necessary for applications such as implants [ 55 , 56 ] and scaffolds [ 57 , 58 ]. Si 3 N 4 ceramics are also characterized by their bacteriostatic properties, which can be useful in a variety of biomedical applications [ 45 , 46 ].…”