Development of Magnetic Silica core-shell nanoparticles loaded with Gentamicin Sulfate for Osteomyelitis treatment

Background: Osteomyelitis, a significant bone infection mainly attributed to Staphylococcus aureus, presents treatment challenges due to inadequate local blood supply and diminished effectiveness of gentamicin (GS) in acidic conditions. Objective: To develop and assess magnetic silica core–shell nanoparticles containing GS (MNP@SiO₂/GS) for targeted antibacterial delivery and to assist in bone regeneration for osteomyelitis treatment. Material and methods: Magnetic nanoparticles (MNPs) were synthesized through a solvothermal reaction, subsequently coated with dense and mesoporous silica, and loaded with GS. Characterization was conducted utilizing zeta potential analysis, Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The antibacterial activity against Staphylococcus aureus was evaluated using the well diffusion method. Results: Zeta potential analysis indicated that silica coating decreased the surface charge of the MNPs from −10.39 mV to −6.34 mV, thereby confirming successful surface modification. The FTIR spectra validated the formation of MNP@SiO₂/GS through the identification of Fe–O, Si–O–Si, and GS peaks. SEM showed spherical MNPs (120 ± 15 nm) and larger porous MNP@SiO₂ (252 ± 37 nm). MNP@SiO₂/GS demonstrated antibacterial activity, whereas unloaded MNP@SiO₂ exhibited no effect. Conclusion: MNP@SiO₂/GS presents a viable approach for the treatment of osteomyelitis through targeted delivery and antibacterial effectiveness.