Polymer-Based Local Antibiotic Delivery for Prevention of Polymicrobial Infection in Contaminated Mandibular Implants

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Oral and Maxillofacial Surgery

Background:

• Porous poly(methyl methacrylate) (PMMA) space maintainers facilitate local antibiotic delivery and tissue integration.
• Poly(DL-lactic-co-glycolic acid) (PLGA) is utilized as a carrier for antibiotic elution.
• Investigating the impact of antibiotic release kinetics and dosage on healing is crucial for optimizing these devices.

Purpose of the Study:

• To evaluate the effect of clindamycin release kinetics and dose from PMMA space maintainers on bacterial clearance and tissue healing.
• To compare burst release versus extended release formulations in a rabbit mandibular defect model.
• To determine if antibiotic release influences healing outcomes independently of bacterial eradication.

Main Methods:

• Fabrication of clindamycin-loaded PMMA space maintainers with varying release profiles (burst vs. extended) and doses.
• Implantation into pathogen-contaminated rabbit mandibular defects.
• Histological analysis to assess inflammation, fibrous capsule formation, and bone regeneration.

Main Results:

• No recovery of inoculated bacteria across all specimen groups.
• Burst release formulation exhibited reduced inflammation and fibrous capsule formation compared to low-dose extended release.
• Burst release formulation demonstrated enhanced bone formation adjacent to the implant relative to low-dose extended release.

Conclusions:

• Local antibiotic release kinetics and dose significantly influence soft and hard tissue healing.
• These effects appear to be independent of the formulation's ability to clear bacteria.
• Optimizing release profiles of antibiotic-eluting devices is critical for regenerative outcomes.