In vivo response to biodegradable controlled antibiotic release systems

Area of Science:

• Biomaterials Science
• Infectious Diseases
• Orthopedic Surgery

Background:

• Implant-related osteomyelitis is a challenging bone infection.
• Effective localized antibiotic delivery remains a critical need for treatment.

Purpose of the Study:

• To evaluate the efficacy of antibiotic-loaded microbial polyester rods for treating experimental implant-related osteomyelitis.
• To assess the therapeutic potential of poly(3-hydroxybutyrate-co-4-hydroxyvalerate) [P(3-HB-co-4-HB)] and poly(3-hydroxybutyrate-co-3-hydroxy- valerate) [P(3-HB-co-3-HV)] rods.

Main Methods:

• In vitro and in vivo studies using rabbit tibia models with Staphylococcus aureus inoculation and metal implants.
• Therapy involved Sulperazone- and Duocid-loaded P(3-HB-co-4-HB) rods at a 1:1 drug to polymer ratio.
• Evaluation through macroscopic, radiological, and histological analysis at weeks 3 and 6.

Main Results:

• Both Sulperazone- and Duocid-loaded P(3-HB-co-4-HB) rods were effective in treating the induced bone infection.
• Significant improvements were observed in radiological parameters (periosteal elevation, bone shaft width, new bone formation) and soft tissue.
• Histological analysis showed subsidence of infection, replacement of inflammatory cells with bone-forming cells, and osteoblastic activity.

Conclusions:

• Antibiotic-loaded biopolymeric rods demonstrate potential as a novel controlled-release system for implant-related and chronic osteomyelitis.
• P(3-HB-co-4-HB) based antibiotic delivery systems show promise for bone infection treatment.