Localized mandibular infection affects remote in vivo bioreactor bone generation

Area of Science:

• Biomaterials Science
• Surgical Innovation
• Infectious Disease Research

Background:

• Mandibular reconstruction faces challenges from bacterial contamination.
• Porous space maintainers offer local antibiotic delivery and soft tissue support.
• Vancomycin is a key antibiotic for combating Gram-positive bacterial infections.

Purpose of the Study:

• To evaluate the efficacy of vancomycin-loaded porous space maintainers in preventing infection and preserving mandibular defects in a sheep model.
• To assess the impact of local infection on bone tissue formation within 3D-printed bioreactors.

Main Methods:

• Sheep models with surgically created mandibular defects were inoculated with Staphylococcus aureus.
• Porous space maintainers, either unloaded or loaded with vancomycin, were implanted.
• 3D-printed bioreactors with autograft or xenograft were implanted adjacent to rib periosteum.
• Tissues were analyzed after 9 weeks to assess infection, inflammation, and bone formation.

Main Results:

• Vancomycin-loaded space maintainers prevented soft tissue dehiscence, reduced inflammation, and eradicated pathogens.
• Unloaded space maintainers did not prevent infection or associated complications.
• Untreated infections led to denser and more mature bone formation in bioreactors.
• Autograft-filled bioreactors demonstrated superior mechanical properties compared to xenograft-filled bioreactors.

Conclusions:

• Antibiotic-releasing space maintainers are a promising strategy for managing infection in mandibular reconstruction.
• Local infection may paradoxically stimulate bone growth, warranting further investigation.
• Autografts show potential for enhanced bone regeneration in bioreactor applications.