Metal‐Phenolic Networks Nanoplatform to Mimic Antioxidant Defense System for Broad‐Spectrum Radical Eliminating and Endotoxemia Treatment

Abstract Oxidative stress occurs when excess oxidative free radicals are produced in cells, which can overwhelm the normal antioxidant capacity and play an important role in many disease states. Thus, advanced functional materials which can mimic the intracellular antioxidant defense system have a huge potential to become candidates for curing oxidative stress triggered diseases. Herein, a high‐performance nanoplatform is developed with a green and mild strategy by combining mimic‐enzymatic antioxidant (Fe 3 O 4 ) and nonenzymatic antioxidant (tannic acid (TA)) for constructing antioxidant defense system (Fe 3 O 4 @ TAn nanoflowers (NFs)). Owing to the excellent peroxidase (POD)‐mimic and catalase (CAT)‐mimic capacities of Fe 3 O 4 in various conditions, the antioxidant ability of TA and the flower‐like morphology, the Fe 3 O 4 @ TAn NFs can effectively scavenge multiple reactive oxygen and nitrogen species. In vitro experiments verify that the Fe 3 O 4 @ TAn NFs demonstrate synergetic antioxidative properties, which can be used to protect blood and cellular components against oxidative damage. Meanwhile, in vivo experiments demonstrate that the Fe 3 O 4 @ TAn NFs exhibit excellent therapeutic effects for systemic inflammation on endotoxemia mice and promote wound healing owing to the excellent antioxidant and anti‐inflammatory properties. Thus, this antioxidant defense system expands the toolbox of antioxidative materials and shows potential applications in oxidative stress treatment.