Enzyme Cascade Nanoreactor for Infection Clearance and Regenerative Immune Remodeling in Orthopedic Biofilm Infection

ABSTRACT

Implant‐associated biofilm infection remains a major obstacle to orthopedic repair because persistent bacterial colonization and dysregulated innate immune responses hinder infection resolution and osseointegration. Here, an acid‐responsive enzyme cascade nanoreactor, CaO ₂ @CuMOF‐GOx, is engineered to couple biofilm metabolic disruption with regenerative immune remodeling. The nanoreactor comprises an oxygen‐generating CaO ₂ component, a Cu‐based metal–organic framework catalytic interface, and immobilized glucose oxidase (GOx). In the acidic and oxygen‐limited biofilm microenvironment, CaO ₂ @CuMOF‐GOx supplies O ₂ to sustain GOx‐catalyzed glucose consumption and generates H ₂ O ₂ that undergoes Cu‐mediated Fenton‐like conversion into hydroxyl radical‐mediated oxidative stress. This cascade disrupts bacterial energy metabolism, redox homeostasis, and membrane integrity, thereby suppressing planktonic bacteria and mature biofilms. Importantly, CaO ₂ @CuMOF‐GOx also reshapes the inflammatory microenvironment by promoting timely neutrophil apoptosis under metabolic and oxidative stress. These apoptotic neutrophils are efficiently cleared by macrophages, leading to efferocytosis‐associated macrophage reprogramming toward a pro‐reparative phenotype and inflammation resolution. Metabolomic profiling and neutrophil RNA sequencing substantiate bacterial metabolic collapse and activation of intrinsic apoptotic programs in neutrophils. In a rat implant‐associated infection model, local CaO ₂ @CuMOF‐GOx treatment reduces bacterial burden, alleviates peri‐implant inflammation, and enhances bone regeneration and osseointegration. This study presents a biofilm‐responsive immunometabolic nanotherapy that integrates infection eradication with regenerative immune remodeling for orthopedic implant‐associated infections.