Engineered sonosensitive probiotics extracellular vesicles coating for ultrasound-driven anti-infection and immunoregulation in implant infection treatment

Implant-associated infections remain a major challenge in bone defect therapy, often leading to implant failures and serious health risks. Traditional treatments rely heavily on systemic antibiotics, which have become less effective due to resistance and limited penetration through bacterial biofilms. This study presents a polyphenol-bridged implant coating that integrates osteogenic growth peptide (OGP)-shielded probiotic-derived outer membrane vesicles (OMVs) with high-penetration sonodynamic therapy (SDT) for controllable antibacterial and osteogenic functions in treating implant-associated infections (IAIs). SDT generates reactive oxygen species (ROS) and leverages the bacteriostatic properties of OMVs for precise deep-tissue antibacterial action. OMVs also protect OGP, enabling controlled ultrasound (US)-triggered release at the targeted site, while inducing macrophage polarization toward an M2-like phenotype, enhancing osseointegration and tissue regeneration. Transcriptomic analyses indicate involvement in adipocytokine, phagosome, and TGF-β signaling pathways, mediating efficient osteogenesis differentiation. This tailored implant coating presents a promising strategy for managing IAIs, addressing both infection control and bone regeneration.