A catalytically active and recyclable bioelastomer inspired by metalloenzymes.

Catalysis is a fundamental principle of biological systems, yet synthetic biomaterials seldom incorporate catalytic activity as a core design principle. Here, we introduce a polymeric network constructed by crosslinking imidazole-functionalized polymers using Cu(2+) ions, yielding an elastomer with enzyme-mimetic reactivity. This bioinspired design enables sustained nitric oxide (NO) generation in serum and broad-spectrum antioxidant activity against superoxide, hydrogen peroxide, and hydroxyl radicals, mimicking the functions of superoxide dismutase, catalase, and peroxidases. Catalytic activity depends on Cu(2+) coordination, confirming a defined structure-function mechanism. The elastomer demonstrates minimal hemolysis, reduced platelet adhesion, and high biocompatibility upon subcutaneous implantation. Remarkably, the material can be fully recycled by a simple immersion in acetic acid that reverses Cu(2+) coordination without compromising the integrity of the polymer. This closed-loop feature aligns with circular economy principles and greatly extends the functional lifespan of the material. By integrating mechanical robustness, catalytic activity, and recyclability, this material bridges a critical gap between natural and engineered systems, establishing a new framework for catalytically active and sustainable biomaterials.