A Wet‐Adhesion and Swelling‐Resistant Hydrogel for Fast Hemostasis, Accelerated Tissue Injury Healing and Bioelectronics

Abstract Hydrogel bioadhesives with adequate wet adhesion and swelling resistance are urgently needed in clinic. However, the presence of blood or body fluid usually weakens the interfacial bonding strength, and even leads to adhesion failure. Herein, profiting from the unique coupling structure of carboxylic and phenyl groups in one component ( N ‐acryloyl phenylalanine) for interfacial drainage and matrix toughening as well as various electrostatic interactions mediated by zwitterions, a novel hydrogel adhesive (PAAS) is developed with superior tissue adhesion properties and matrix swelling resistance in challenging wet conditions (adhesion strength of 85 kPa, interfacial toughness of 450 J m −2 , burst pressure of 514 mmHg, and swelling ratio of <4%). The PAAS hydrogel can not only realize fast hemostasis of liver, heart, artery rupture, and sealing of pulmonary air‐leakage but also accelerate the recovery of stomach and liver defects in rat, rabbit, and pig models. Moreover, PAAS hydrogel can precisely and durably monitor various physiological activities (pulse, electrocardiogram, and electromyogram) even under humid environments (immersion in water for 3 days), and can be employed for the evaluation of in vivo sealing efficiency for artery rupture. The work provides a promising hydrogel adhesive for clinical hemostasis, tissue injury repair, and bioelectronics.