TPMS Microarchitectures for Vertical Bone Augmentation and Osteoconduction: An In Vivo Study.

Area of Science:

• Biomaterials Science
• Materials Engineering
• Tissue Engineering

Background:

• Triply periodic minimal surface (TPMS) microarchitectures are inspired by natural structures and known for their lightweight, robust properties.
• TPMS find applications in aerospace and automotive industries, and show potential as bone substitutes due to their intricate geometry.

Purpose of the Study:

• To produce and evaluate three TPMS microarchitectures (D-diamond, G-gyroid, P-primitive) using 3D-printed hydroxyapatite.
• To investigate the mechanical properties, bone augmentation, and osteoconduction potential of these TPMS scaffolds.

Main Methods:

• Three TPMS microarchitectures (D-diamond, G-gyroid, P-primitive) were fabricated via 3D printing using hydroxyapatite.
• Mechanical characterization was performed.
• In vivo studies were conducted using calvarial defect and bone augmentation models to assess osteoconduction and bone ingrowth.

Main Results:

• D-diamond and G-gyroid TPMS exhibited significantly higher mechanical strength compared to P-primitive.
• G-gyroid demonstrated superior performance in both bone defect bridging (osteoconduction) and bone ingrowth (augmentation) compared to P-primitive.
• No significant performance difference was found between G-gyroid and D-diamond in the in vivo models.

Conclusions:

• Hydroxyapatite scaffolds with D-diamond and G-gyroid TPMS microarchitectures are suitable for bone tissue engineering.
• These structures show excellent potential for treating bone deficiencies, combining defect bridging and bone augmentation capabilities.