Tissue-Integrated Hydrogel Battery-Enabled Electroceutical for Cardiac Arrhythmia Management.

Conventional implantable bioelectronic devices for cardiac arrhythmia management are bulky, invasive, prone to mechanical failure and immune rejection. Here, we introduce a standalone bioadhesive hydrogel battery-enabled electroceutical device that seamlessly interfaces with cardiac tissue, enabling rapid electrochemical modulation of cardiac rhythm. Constructed from dynamic supermolecular hydrogels, the device achieves strong electrode-electrolyte adhesion and suture-free integration with biological tissue (adhesion energy > 200 J m-2). It provides stable in vivo voltage outputs (0.90-1.17 V) for 14 days while suppressing immune response as indicated by downregulating inflammatory biomarkers. The battery discharge enhances cardiomyocyte contraction, promotes cell junction protein expression, and mediates cardiac arrhythmias in ex vivo rat hearts. Adhering directly to the myocardium without surgical fixation, the device generates sustained electrical stimulation for bradycardia correction and low-energy defibrillation, restoring sinus rhythm within seconds (5-10 s) in a rat model. This tissue-integrated electroceutical offers a promising alternative during cardiac surgery to treat arrhythmia by enhancing tissue integration and minimizing foreign-body response.