Chitosan sponges as a sustained release carrier system for the prophylaxis of orthopedic implant-associated infections.

The present investigation aims to study the chitosan sponge as a carrier matrix for the sustained antibiotic release system for the prophylaxis of orthopedic implant-associated infections (OIAIs). We have prepared sponges of three broad-spectrum antibiotics, namely vancomycin, ciprofloxacin and cefuroxime possessing different physicochemical properties. The blank, vancomycin, ciprofloxacin and cefuroxime loaded chitosan sponges were denoted as Blank-CH, CH-VAN, CH-CIP, and CH-CEF sponges. Chitosan sponges were assessed for morphology, drug-release, antibacterial potential, and preclinical evaluation using a rat subcutaneous implantation model. The results revealed that the physicochemical properties of the drug incorporated into the chitosan matrix play an important role in the morphology, degradation and drug release profile. Due to the highly hydrophilic properties of vancomycin, the CH-VAN sponge showed the highest swelling and fastest degradation profile. The CH-VAN sponge demonstrated the short-term release in contrast with the CH-CEF and CH-CIP sponges, which showed sustained release along with sustainable antibacterial activity. The preclinical evaluation proved that the CH-CIP and CH-CEF sponges were biodegradable, non-toxic and biocompatible. Further, the CH-CIP and CH-CEF sponges were able to maintain minimum plasma concentration with higher local tissue antibiotic concentration. Therefore, the CH-CIP and CH-CEF sponges could be promising candidates for the long-term prophylaxis of OIAIs.