Vancomycin-loaded bone substitute as a ready-to-use drug delivery system to treat osteomyelitis

Affecting annually millions of people worldwide, osteomyelitis is a critical bone infection caused by pathogenic organisms which poses a serious health issue. The standard treatment involves debridement of infected bone, systemic administration of antibiotics and subsequent bone reconstruction. However, the systemic route of administration can be ineffective and associated with severe side effects. This work focused on the development of lyophilized vancomycin-loaded heparinized nanohydroxyapatite/collagen granules to facilitate clinical application, addressing infection eradication and bone regeneration. A local bone substitute delivery system was developed as an attractive alternative solution not yet commercially available. The lyophilization process has proven to be effective with a controlled release of the antibiotic for a longer period, above minimum inhibitory concentration for methicillin-resistant Staphylococcus aureus (MRSA), when compared to non-lyophilized granules. This system totally inhibits the growth of planktonic and sessile MRSA. Moreover, the material promoted osteoblasts metabolic activity and proliferation, while inducing neovascularization. Overall, this work advanced towards the deployment of a reliable solution in clinical practice developing a ready-to-use drug delivery system avoiding the process of antibiotic handling and preparation before surgery.