Soft Bio-Electroactive Hydrogels for Musculoskeletal Tissue Repair and Rehabilitation

Musculoskeletal tissue repair and rehabilitation face significant challenges in effectively repairing injured tissues and achieving functional recovery. Recent advancements highlight the crucial role of electrical conductivity in modulating cellular activity, promoting tissue repair, and enhancing recovery. This understanding leads to the development of bio-electroactive materials that combine biocompatibility with electrical conductivity to interact with biological systems. Among these, conductive hydrogels (CHs) are designed to transmit electrical cues, modulating cellular behavior, facilitating tissue regeneration, and supporting electrophysiological functions. Due to their mechanical flexibility, high electrical conductivity, and ability to stimulate and record bioelectrical signals, CHs are especially effective for repairing electroactive tissues such as bone, cartilage, tendons, ligaments, skeletal muscle, and peripheral nerves, which rely on electrical signaling for physiological function and repair. This review provides an overview of bio-electroactive CHs in musculoskeletal tissue repair and rehabilitation, focusing on the design and synthesis of various types, including conductive polymer-based, ionic-based, metallic nanoparticle-based, and composite-based CHs. Additionally, the review explores the applications of CHs in promoting musculoskeletal tissue repair and highlights recent advances in closed-loop rehabilitation. Finally, the emerging trends, challenges, and prospects in CHs development are discussed, offering insights for future research and clinical applications in musculoskeletal repair and rehabilitation.