Bacterial Outer Membrane‐Based Biomimetic Immune Adaptors: Mild Immunomodulatory and Bacterial Targeted Delivery Strategy Against Implant‐Related Infections

Abstract Implant‐related infections (IRIs) are difficult to manage and are a major cause of surgical failure. The formation of biofilms with a solid barrier on the surface of implants and concomitant suppression of the local immune response constitute major challenges for treating IRIs. This study develops a multifunctional biomimetic immune adaptor (Hybrid Membrane@Levo@SiO 2 ; HMLS) generated by loading the antibiotic levofloxacin (Levo) into silica nanoparticles and coating the particles with a hybrid membrane formed from outer membrane vesicles (OMVs) of Escherichia coli and red blood cell membranes (RBCMs). The HMLS nanoplatform is designed to address the challenges associated with IRIs through a dual‐approach strategy. First, the unique immunogenicity of OMVs regulates the antibacterial immune responses of innate immune cells and reverses the immunosuppressive microenvironment around IRIs. Second, the homotypic targeting effect of OMVs in the hybrid membrane provides HMLS with bacterial targeting functions and efficient bactericidal effects. Additionally, the RBCMs endow the hybrid membrane with mild immunogenicity, which prevents excessive inflammatory stimulation. The synergistic strategy of HMLS exhibits superior antibiofilm effects both in vivo and in vitro, providing a new option for the clinical treatment of refractory IRIs.