Bone morphogenetic protein-2 sustained delivery by hydrogels with microspheres repairs rabbit mandibular defects

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Oral and Maxillofacial Surgery

Background:

• Mandible defects present significant challenges in dental surgery due to limited treatment options.
• Recombinant human bone morphogenetic protein-2 (rhBMP2) is known for its osteoinductive properties, promoting bone regeneration.

Purpose of the Study:

• To develop and evaluate chitosan/collagen hydrogels incorporating rhBMP2-loaded gelatin microspheres (GMs) for sustained rhBMP2 release.
• To assess the efficacy of this complex delivery system in inducing bone regeneration in rabbit mandible defects.

Main Methods:

• Chitosan/collagen hydrogels with rhBMP2-GMs were prepared and characterized.
• Mandibular defects were created in rabbits and treated with hydrogels alone, rhBMP2-hydrogels, or hydrogels with rhBMP2-GMs.
• Bone regeneration was evaluated using scanning electron microscopy, in vitro release studies, computed tomography, and histological analysis at 2, 6, and 12 weeks.

Main Results:

• Gelatin microspheres were spherical, and the hydrogel-GM complex demonstrated ideal in vitro release profiles.
• Significant new bone formation was observed in defects treated with hydrogels containing rhBMP2-GMs within 12 weeks.
• This complex delivery system outperformed hydrogels alone or rhBMP2-loaded hydrogels in promoting mandible defect healing.

Conclusions:

• Chitosan/collagen hydrogels with rhBMP2-incorporated GMs provide a promising sustained delivery system for rhBMP2.
• This approach significantly enhances bone regeneration in mandible defects, offering a potential therapeutic strategy for dental surgery.