Cranial Defect Reconstruction With Custom 3D-Printed Hydroxyapatite Scaffolds Augmented With rhBMP-2 or Dipyridamole...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Craniofacial Surgery

Background:

• Critical-sized bone defects, especially in the cranio-maxillofacial region, pose significant reconstruction challenges.
• Bone tissue engineering (BTE) offers a potential solution for regenerating bone and integrating with host tissues.

Purpose of the Study:

• To evaluate the clinical readiness of 3D-printed hydroxyapatite scaffolds augmented with rhBMP-2 or dipyridamole (DIPY) for cranial defect reconstruction in a nonhuman primate model.

Main Methods:

• Custom 3D-printed hydroxyapatite scaffolds were implanted into critical-sized cranial defects in macaques.
• Groups included uncoated scaffolds, rhBMP-2 augmented scaffolds, and DIPY augmented scaffolds.
• Assessment involved serial CT scans, micro-CT, histology, and nanoindentation over 12 months.

Main Results:

• rhBMP-2 augmented scaffolds demonstrated significantly greater bone bridging (~90%) and bone volume compared to DIPY (~9%) and uncoated scaffolds (10%).
• Histology revealed higher bone ingrowth (~64%) with rhBMP-2 compared to DIPY (~39%) and uncoated scaffolds (~27%).
• Nanoindentation showed superior mechanical properties (Young's modulus, hardness) for bone regenerated with rhBMP-2 scaffolds.

Conclusions:

• 3D-printed hydroxyapatite scaffolds are effective for reconstructing critical-sized cranial defects.
• rhBMP-2 augmentation significantly improves bone ingrowth, integration, and mechanical properties, presenting a viable alternative for cranioplasty.