Biopolymer Local Delivery Device Loaded with Rifampin and Ciprofloxacin to Inhibit Biofilm Formation

Increases in patients\u27 costs, multiple surgeries, and difficult treatment solutions are resultants of musculoskeletal infections. The presence of biofilm-forming or antibiotic resistant bacteria exponentially increase the complexity and complications in treatment of those musculoskeletal infections. During this study, the combination of ciprofloxacin and rifampin loaded in and released from chitosan-based local delivery systems was evaluated as an adjuvant therapy for prompt reduction of biofilm-forming bacteria in the wound when locally delivered. Primary assessments included antibiotic release, sponge eluate in vitro activity, in vitro synergy assays, effect on chitosan sponge pore structure, and an in vivo implant associated biofilm functional model. Antibiotic activity was present through seven days against S. aureus and P. aeruginosa. Ciprofloxacin had a therapeutic elution profile that lasted, at least, seven days while rifampin\u27s lasted three days. Additive effects were present against P. aeruginosa during the in vitro synergy assay with inconclusive results against S. aureus. No unexpected or adverse effects on chitosan sponge pore structure were seen after sponges were loaded with the antibiotic cocktail. Complete clearance of biofilm-forming S. aureus and E. coli with no noticeable adverse effects were achieved in the functional infected pin murine model. The results of this study support the potential use of ciprofloxacin and rifampin in chitosan-based local deiivery devices, as local adjunctive therapy, for prevention of musculoskeletal and surgical site infections