Coaxial electrospun fibers for control release of vancomycin and diclofenac in osteomyelitis management

Osteomyelitis (OM) is a serious bacterial bone infection and can be life-threatening if not treated promptly. A promising approach to manage OM involves using drug-loaded fibrous implants or scaffolds containing antibiotics, analgesics, or anti-osteoporosis medications to combat infection, reduce pain and promote bone healing, respectively. In this study, a coaxial electrospinning technology was employed to fabricate drug-loaded fibers encapsulating vancomycin hydrochloride (VAN), an antibiotic, and diclofenac sodium (DIC), an analgesic to prevent infection and alleviate post-surgical pain. The fibers were characterized using scanning electron microscopy (SEM) which indicated that the drug-loaded (DL) coaxial fibers had smooth surfaces and lacked beads and pores. The drug loading of the DL coaxial fibers was estimated by high-performance liquid chromatography (HPLC), and the results were calculated as 75 ± 4 µg/mL for VAN and 82 ± 3 µg/mL for DIC. The drug release was also measured by HPLC, which showed a rapid initial release, i.e., 59% for VAN and 75% for DIC within the first day, followed by a sustained slow release reaching approximately 92% and 79%, respectively after 264 h. The antimicrobial assay zone of inhibition confirmed the antibacterial activity of the DL fibers against Staphylococcus aureus. The cell viability assessments on the drugs alone against human dermal fibroblasts (HFF-1) demonstrated that the VAN and DIC combination is safe at concentrations up to 250 µg/mL but required careful dosing due to time-dependent cytotoxicity. Overall, the study highlights the potential use of VAN and DIC-loaded coaxial electrospun fibers as a localized drug delivery system for OM treatment, offering controlled drug release, effective antibacterial action, and biocompatibility.