A Biodegradable Piezoelectric Vertebral Implant for Programmable Electro-neuromodulation in Spinal Cord Injury

Here, we report a biodegradable piezoelectric cryogel (Piezo Gel) that enables programmable electro-neuromodulation without implanted electronics. Mimicking spinal biomechanics, Piezo Gel converts physiological movement into localized endogenous electric fields, while externally applied ultrasound (US) amplifies its electrical output, enabling on-demand in situ programming.

In a rat model of acute severe SCI, US-activated Piezo Gel significantly enhanced locomotor recovery, improved Basso–Beattie–Bresnahan (BBB) scores, and promoted bladder functional remodeling. In a mild contusion model, we further implemented a phase-adaptive neuromodulation strategy, shifting from US-driven stimulation during acute immobility to movement-driven stimulation during subacute rehabilitation, aligning with the evolving spinal microenvironment.