Engineering Human-Scale Artificial Bone Grafts for Treating Critical-Size Bone Defects.

Area of Science:

• Biomaterials Engineering
• Regenerative Medicine
• Tissue Engineering

Background:

• Current bone grafting methods face challenges for critical-size defects.
• Pathological disorders, trauma, and tumor ablation create significant bone loss.
• Need for patient-specific solutions in bone defect repair.

Purpose of the Study:

• To develop a patient-specific fabrication process for artificial bone grafts.
• To create biomimetic scaffolds mimicking natural bone composition and structure.
• To evaluate scaffold biocompatibility, osteogenic potential, and in vivo performance.

Main Methods:

• Laser stereolithography used to create patient-specific bone defect replicas.
• Polydimethylsiloxane (PDMS) molds created from defect replicas.
• Gas-in-water foams cast in molds, followed by freeze-drying and cross-linking.
• Biomimetic scaffolds fabricated using gelatin and hydroxyapatite.
• Scaffold characterization for porosity, pore size, and interconnectivity.

Main Results:

• Scaffolds accurately replicated bone defect models with appropriate porous texture.
• Average pore size of ~300 μm and interconnects of ~100 μm achieved with 90% porosity.
• In vitro studies with human mesenchymal stem cells (hMSCs) confirmed biocompatibility and osteogenic differentiation.
• In vivo implantation demonstrated bone matrix deposition and vascularization.

Conclusions:

• The developed technique enables fabrication of mechanically stable, bioactive, and biocompatible composite scaffolds.
• Scaffolds possess well-defined architectures suitable for cellular infiltration and vascularization.
• This approach holds significant potential for regenerating patient-specific bone defects.