NIR‐Responsive CaMoO 4 /Mo 3 N 2 Heterojunction Modified Biomimetic Periosteum: Synergistic Anti‐Infection and Promotion of Bone Defect Repair

ABSTRACT Treating infected bone defects remains a formidable clinical challenge due to robust bacterial antioxidant resistance and severe microenvironmental deterioration. Herein, an antibacterial biomimetic periosteum (ABP) is rationally engineered by in situ anchoring ultrasmall CaMoO 4 /Mo 3 N 2 heterojunctions onto a porous bioactive glass fiber membrane (CMO/MN) via a sol‐gel electrospinning and nitridation strategy. These hierarchical ABPs transform passive bone implants into active metabolic modulators. Under near‐infrared irradiation, the CaMoO 4 /Mo 3 N 2 engine initiates localized hyperthermia alongside a sophisticated multienzyme cascade. Specifically, peroxidase‐like activity generates a wide range of highly toxic reactive oxygen species, while intrinsic glutathione oxidase and L‐cysteine oxidase activities persistently deplete bacterial antioxidants, effectively dismantling fundamental oxidative defenses. In addition, catalase‐like activity continuously decomposes endogenous H 2 O 2 into O 2 , mitigating localized tissue hypoxia and inflammatory oxidative stress. Furthermore, this biomimetic three‐dimensional fiber network achieves a powerful osteogenic induction effect by continuously releasing therapeutic calcium ions and silicate ions. In vitro experiments have confirmed the excellent biocompatibility of ABPs and their ability to promote the osteogenic differentiation of bone marrow mesenchymal stem cells, while simultaneously exhibiting potent bactericidal activity against bacteria. Consistently, ABPs have also demonstrated superior therapeutic performance in the treatment of both uncomplicated bone defects and infection‐compromised bone defects.