Bioabsorbable Si-Mg galvanic cells in flexible scaffolds for symbiotic electrical stimulation to promote nerve regeneration

Electrical stimulation treatment represents a new paradigm for tissue regeneration and reconnection. However, the deployment of electrical stimulation devices on damaged and dynamic tissues in vivo remains challenging. Here, we present transient Si–Mg galvanic cell scaffolds for symbiotic electrical stimulation scaffolds (SESS), where tissue fluids act as the electrolyte to drive the galvanic reaction, enabling month-long nonlinear and adaptive electrical stimulation for enhancing nerve regeneration and reconnection. The SESS integrates all biodegradable materials into a seamless textile, enabling deployment on dynamic tissues and full degradation that eliminates the need for secondary removal surgery. Owing to the suitable impedance and biocompatibility of the semiconductor silicon-biological interface, SESS can generate up to month long effective electrical output. SESS showed therapeutic efficacy comparable to autologous nerve grafts in a 10-mm rat sciatic nerve defect model. Notably, the therapeutic effects from degradation products and electrical stimulation have been decoupled and determined via mirror-symmetric deployment. This work should provide new insights and pathways for the development of galvanic cell bioelectronics.