Microwave-Responsive Fe3O4/Prussian Blue Heterostructure-Integrated Bone Scaffolds for Osteomyelitis Treatment

Abstract

Chronic osteomyelitis is a severe clinical challenge due to its high recurrence rates and poor antibiotic penetration. Microwave thermal therapy (MTT) has emerged as a potential strategy to address these issues owing to its noninvasiveness and deep tissue penetration. However, its therapeutic efficacy is often limited by single-component microwave sensitizers with low conversion efficiency and poor impedance matching. In this study, a Fe3O4/Prussian blue heterointerface (Fe3O4/PB) was synthesized and integrated into poly-l-lactic acid (PLLA) scaffolds via selective laser sintering to develop a microwave-responsive therapeutic platform for osteomyelitis treatment. Benefiting from Fe3O4/PB, the scaffold exhibited optimized electromagnetic parameters through the synergistic contributions of magnetic loss, dielectric loss, and interfacial polarization, thereby improving impedance matching and microwave absorption capability. Under microwave irradiation, the scaffold rapidly heated to ∼45 °C within 10 min and simultaneously generated abundant reactive oxygen species, enabling a combined thermal-dynamic antibacterial effect. In vitro assays demonstrated that the scaffold achieved bactericidal rates of up to 94.7% against both Staphylococcus aureus and E. coli while inhibiting biofilm formation by more than 80%. Overall, this study introduces a scaffold-based strategy for treating osteomyelitis by combining microwave thermal and dynamic therapies.