Self-Bondable and Strain-Durable Electroceuticals Using Self-Healing and Stretchable Conducting Nanocomposite Trilayer for Effective Vagus Nerve Stimulation

Vagus nerve stimulation (VNS) is a promising therapy for neurological and inflammatory disorders across multiple organ systems. However, conventional rigid interfaces fail to accommodate dynamic mechanical environments, leading to mechanical mismatches, tissue irritation, and unstable long-term interfaces. Although soft neural interfaces address these limitations, maintaining mechanical durability and stable electrical performance remains challenging. Herein, we introduce a self-bondable and strain-durable electroceutical (SSE) as an effective platform for VNS. The SSE self-bonds around the vagus nerve without fixation tools, ensuring stable interfacing through the intrinsic self-bonding property of the self-healing polymer (SHP), while the stress relaxation properties minimize strain and tissue damage. The trilayer-structured electrode enhances the wiring capability and electrical durability under cyclic mechanical stress through interactions between the SHP matrix, conductive silver (Ag) flakes, and a carbon nanotube (CNT) network. Additionally, the synergistic combination of poly(3,4-ethylenedioxythiophene) polystyrenesulfonate and the CNT network improves the electrochemical stability and prevents leakage of Ag ions, thereby addressing cytotoxicity concerns. To evaluate the therapeutic potential, the SSE was applied in a drug-induced seizure rodent model, and electroencephalogram (EEG) monitoring was performed to distinguish between normal, seizure, and post-VNS states. Quantitative EEG analysis demonstrated significant modulation of the power spectra and peak frequencies, confirming the therapeutic efficacy of VNS. Histological analysis revealed minimal inflammation, thus validating the biocompatibility of the electrodes. These findings establish SSE as a robust and adaptable electroceutical platform for the treatment of epilepsy and for broader neuromodulation applications.