Biomimetic Osteochondral Biobattery

ABSTRACT Bioelectric cues are critical for articular cartilage (AC) repair, yet existing biobatteries lack sufficient flexibility, degradability, and the capacity to deliver sustained, directional electrical stimulation in vivo. Here, we report a biodegradable, self‐powered biobattery scaffold, fabricated by multimaterial 3D printing, that overcomes these limitations. Based on a Zn–MnO 2 electrochemical pair, the scaffold generates a stable endogenous electric field (∼0.6 V) that directs bone marrow mesenchymal stem cell (BMSC) recruitment and migration via galvanotaxis. Simultaneously, controlled degradation of the Zn and MnO 2 electrodes releases Zn 2 + and Mn 2 + ions, which respectively drive osteogenic and chondrogenic differentiation, enabling spatially coordinated, zonal tissue formation. A printed tidemark‐mimicking separator further restricts vascular invasion and guides the hierarchical integration of regenerated tissues. In a rabbit osteochondral defect model, this biobattery scaffold achieved synergistic regeneration of hyaline‐like cartilage and subchondral bone within 12 weeks, surpassing single‐cue treatments. These findings establish a versatile bioelectrochemical strategy that couples physical, chemical, and structural cues to orchestrate regeneration of complex, multilayered musculoskeletal tissues.