Investigation of Antibiotic-Releasing Biodegradable Composite Bone Cements for Treating Experimental Chronic Maxillofacial Bone Infection

Chronic osteomyelitis of the maxillofacial bones (i.e., jaw bones) is a persistent infection that requires effective treatment. Because systemic antibiotics seldom reach necrotic areas to remove bone infection, local antibiotic carriers such as antibiotic-loaded bone cement can be tried. It is critical to assess the biosafety and efficacy of two new antibiotic-loaded biodegradable composite bone cements for treating chronic mandibular osteomyelitis, and their drug eluting efficiency and other relevant aspects prior to clinical trial. The physico-mechanical properties, and drug release capacity of the cements were determined to be suitable for in vivo application. After inducing chronic osteomyelitis with Staphylococcal strains in 30 female rabbit mandibles, bioactive glass composite cement (0.5 g) and biphasic calcium phosphate composite cement (0.5 g) were implanted in 18 defects (nine/test group) for 84 days to compare the therapeutic efficacy with traditional therapy (control, debridement plus antibiotics in nine defects) using microscopic, micrographic, and radiological examination. Antibiotic concentrations in bone (vancomycin: 34.7–53.2 μg/g, tobramycin: 2.1–2.87 μg/g) after 21 days of installation for both cements were sufficient to eradicate pathogens without causing adverse events. In vivo tests suggest that cement groups outperformed (p < 0.05) traditional therapy in terms of infection clearance and osteoconduction. The gross histologic and micrographic scores of biphasic calcium phosphate composite cement (10.33 ± 0.58 and 8.33 ± 1.53, respectively) indicated that the cement barely surpassed (p > 0.05) the other composite cement (12.67 ± 1.53 and 10.0 ± 1.0, respectively). These findings emphasize the potential of antibiotic loaded composite cements as an effective treatment option for chronic maxillofacial osteomyelitis, offering a safer and more efficient alternative to traditional therapy.