A Janus hydrogel that enables wet tissue adhesion and resists abdominal adhesions

Hydrogels have indeed achieved significant advancements, yet their clinical translation has been hampered by their inherent limitations in wet adhesion properties. Furthermore, the design of adhesive hydrogels that can resist postoperative adhesions remains an intricate challenge. In this study, we introduce a Janus hydrogel (JGP) that offers a novel approach to address these challenges. The JGP hydrogel has two asymmetrical sides, consisting of an adhesion layer (AL) and an anti-adhesion layer (AAL). Specifically, the AL incorporates three key components: N-[tris(hydroxymethyl)methyl]acrylamide (THMA), acrylic acid (AAc), and the acrylic acid N-hydroxysuccinimide ester (AAc-NHS). By drying the AL, it has a rapid water absorption capability. The abundance of hydroxyl and carboxyl groups in the AL enables the formation of robust hydrogen bonds with tissues, thereby achieving superior adhesive properties. Additionally, the synergistic effect of THMA's tridentate hydrogen bonding and the covalent bonding formed by AAc-NHS with tissue ensures long-lasting wet adhesion. To realize the anti-adhesion function, one side of the AL was immersed in a solution of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), which undergoes crosslinking to form the AAL. A comprehensive series of tests have confirmed that the JGP hydrogel exhibits exceptional mechanical properties, efficient and enduring adhesion, excellent biocompatibility, and degradability. Moreover, it possesses remarkable hemostatic properties and robust anti-abdominal adhesion characteristics. Abstract Figure: To fill the gap of wet tissue adhesion materials in the clinic, we designed a tissue patch that can be quickly and permanently adhered. The mechanism of wet tissue adhesion mainly includes rapid absorption of surface water and synergistic effects of multiple hydrogen and covalent bonds. In addition, considering that abdominal adhesions are likely to form after surgery, we added an anti-adhesion layer consisting of amphiphilic ions on the surface of the patch, which can effectively form a hydration layer on the surface to prevent abdominal adhesions. [Display omitted] •This study describes a hydrogel with good wet tissue adhesion properties.•One-sided immersion confers asymmetric adhesion to hydrogel patches.•The tissue patch is effective in preventing postoperative tissue adhesion.•The tissue patch has good biocompatibility and degradability.