An injectable conductive hydrogel for closed-loop and robot-assisted rehabilitation via stretchable patch-type electrodes

Conventional therapies for severe musculoskeletal and neurological injuries require lengthy recovery periods, which may result in residual disabilities. As an innovative rehabilitation approach, the combination of soft conducting hydrogels as an injectable tissue prosthesis with self-healing, stretchable bioelectronic devices offers a promising solution to expedite tissue repair and enhance functional restoration. This class of tissue prostheses can help address the critical limitations of traditional materials and devices by providing a minimally invasive approach to filling tissue defects and reconstructing the electrophysiological environment. The integration of an injectable tissue prosthesis with exoskeleton robotics in closed-loop systems enables tailored rehabilitation interventions that optimize motor function efficiency. Here we provide the step-by-step instructions for the development and characterization of injectable tissue-interfacing conductive hydrogels and soft self-healing, stretchable bioelectronic devices. We also describe how to establish a fully integrated closed-loop rehabilitation system and show its efficacy in a rat model of volumetric muscle loss. Using this approach, we have achieved accelerated tissue regeneration and improved myofiber regeneration in rats, underscoring the potential of this approach to improve rehabilitation strategies for severe injuries. The protocol is suitable for users with experience in biomaterials, devices and animal handling and requires 30 d to complete.