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

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Tissue Engineering

Background:

• Spine-related disorders are a significant global health challenge.
• Effective spinal fusion implants require biomaterials with osteogenic capacity and mechanical properties matching host bone.
• Current implants necessitate development of advanced materials and structures.

Purpose of the Study:

• To fabricate and evaluate 3D-printed polyether ether ketone/silicon nitride (PEEK/SiN) scaffolds with triply periodic minimal surface (TPMS) structures for spinal fusion applications.
• To assess the mechanical properties, dynamic response, and osteogenic potential of these PEEK/SiN scaffolds.
• To determine the suitability of PEEK/SiN TPMS scaffolds as bone graft substitutes.

Main Methods:

• Fabrication of 3D-printed PEEK/SiN scaffolds utilizing TPMS architecture.
• Mechanical testing to evaluate compressive strength and elastic modulus at varying porosities.
• Finite element analysis to assess mechanical properties and dynamic response.
• In vitro biological evaluation to assess osteogenic differentiation.

Main Results:

• Scaffolds with 30% porosity demonstrated mechanical properties (compressive strength: 34.56 ± 1.91 MPa, elastic modulus: 734 ± 64 MPa) comparable to trabecular bone.
• The PEEK/SiN TPMS scaffolds exhibited favorable damping characteristics.
• Incorporation of silicon nitride into PEEK scaffolds significantly promoted osteogenic differentiation.

Conclusions:

• PEEK/SiN TPMS scaffolds possess mechanical and dynamic properties suitable for spinal fusion implants.
• These scaffolds demonstrate excellent osteogenic potential, promoting bone regeneration.
• PEEK/SiN TPMS scaffolds represent a promising biomaterial for bone tissue engineering and spinal fusion applications.