Adhesive-Electrocoupling Hydrogels for Tissue Regeneration: Design, Mechanisms, and Perspectives

Endogenous bioelectric signals serve as pivotal physiological cues that govern cellular behavior and tissue regeneration. Conductive hydrogels have become a disruptive platform in the field of tissue engineering because they can promote tissue repair by utilizing endogenous electrical signals. Conventional conductive hydrogels often suffer from weak tissue adhesion and high contact impedance, which sever the continuity of endogenous bioelectric signals essential for regeneration. To bridge this gap, polyphenol-based adhesive-electrocoupling hydrogels have garnered increasing attention. The conductive network within adhesive-electrocoupling hydrogels facilitates electron transfer-mediated polyphenol redox cycling, preserving catechols for robust adhesion. This strong tissue interface integration maintains electrical signal transduction, constructing a conductive-adhesive synergistic circuit. This review first elucidates the biological effects of bioelectricity, establishing a theoretical foundation for conductive hydrogels to promote tissue repair using endogenous electrical signals. Subsequently, this review systematically summarizes the design strategies for adhesive-electrocoupling hydrogels mediated by polyphenol redox interactions, grounded in electron transfer mechanisms. Crucially, this review introduces the distinct biological mechanisms driving regeneration, highlighting the synergistic interplay among the intrinsic bioactivity of polyphenols, the modulation of cell behavior through endogenous electric field coupling, and cell adhesion. Furthermore, the versatile applications of adhesive-electrocoupling hydrogels in repairing electro-sensitive tissues are critically examined. Finally, this review discusses the current challenges and prospects.