In situ electrocrosslinkable and immiscible bioadhesive for robust underwater electrophysiological signal interfaces

Effective electrophysiological signal transmission is crucial for tissue regeneration, rehabilitation, and bioelectronic applications, particularly in electrically active tissues such as nerves and muscles. However, existing interface materials face significant limitations, including electrical insulation, instability under physiological conditions due to poor underwater adhesiveness, and incompatibility with irregular tissue surfaces. To address these issues, we propose a conductive bioglue (CBG) comprising hyaluronic acid (HA)-coated eutectic gallium indium (EGaIn) nanodroplets with bioengineered mussel adhesive protein (MAP). This water-immiscible liquid-state CBG undergoes in situ crosslinking electrically, exhibiting excellent adhesion to underwater tissue and metal surfaces, suitable mechanical properties, and robust electrical conductivity. In vivo evaluations demonstrated its ability to restore acute and sustained tissue function while enhancing bioelectronic interfacing. These findings underscore the potential of CBG as a promising biocompatible conductive adhesive interface material for efficient in vivo transmission of electrophysiological signals, offering transformative applications in tissue engineering and bioelectronic devices.