Bone Regeneration in Rat Calvaria Using 3D-Printed Scaffolds with Graded Porosity and In Vitro Degradation

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Craniofacial Surgery

Background:

• Craniofacial bone defects pose significant clinical challenges due to complexity and neurological risks.
• Developing effective bone regeneration strategies is crucial for reconstructive surgery.
• Dental pulp stem cells (DPSCs) offer potential for osteogenesis in bone defect repair.

Purpose of the Study:

• To fabricate and characterize a 3D polylactic acid (PLA) scaffold with graded porosity.
• To evaluate the osteoconductive potential of PLA scaffolds using Dental Pulp Stem Cells (DPSCs) in a rat calvarial defect model.
• To assess the impact of in vitro degradation on scaffold performance for craniofacial bone regeneration.

Main Methods:

• Fabrication of a 3D PLA scaffold with graded porosity and three pore types.
• In vitro degradation study over 180 days, monitoring morphology, weight, pH, and mechanical properties.
• Seeding DPSCs onto scaffolds and evaluating osteoconductive performance in a critical-size calvarial defect model in Wistar rats.
• Analysis using microcomputed tomography and bone mineral density.

Main Results:

• Scaffolds showed no significant changes in physical or mechanical properties during 180 days of degradation.
• PLA scaffolds degraded for 60 days exhibited enhanced biological activity in cell-based assays.
• In vivo implantation demonstrated substantial new bone formation in defects treated with degraded scaffolds, even without cells.
• The group receiving degraded scaffolds without cells showed the most significant bone regeneration.

Conclusions:

• The 3D PLA scaffold demonstrates stable physical and mechanical properties during degradation.
• Sixty-day degraded scaffolds exhibit improved biological activity and osteoconductive potential.
• These findings suggest PLA scaffolds are a promising biomaterial for craniofacial bone defect repair.
• Further preclinical validation is warranted for potential clinical translation in regenerative medicine.