Fabricated adhesive hydrogel patches via regulating weak physical interactions through carboxylated cellulose nanofibers

Hydrogel has a similar modulus and water content to human tissues, making it an excellent medical material for wound dressings. Currently, hydrogel wound dressings face issues such as unclear mechanisms, complex synthesis processes, chemical reagent toxicity, lack of on-demand bonding, and low mechanical properties, particularly poor adhesion strength. Fabricating highly adhesive hydrogel patches in wet environments remains a challenge. In this work, we have successfully constructed a biosafe PVA@PAA hydrogel by regulating weak physical interactions within the polymer networks, enhancing the adhesion performance of hydrogels to soft tissues. Results indicated that regulating weak physical interactions, such as hydrogen bonding, could significantly enhance the adhesive properties of hydrogels with soft tissues. Incorporating 0.5 wt% C-CNF into PVA@PAA hydrogel resulted in a 181.02 % and 170.97 % increase in adhesive and tensile strength, respectively. PVA@PAA hydrogel exhibited strong adhesion to soft and wet tissues like chicken heart, gizzard, liver, and rabbit kidney. Cytotoxicity assays demonstrated excellent biocompatibility, confirming its suitability as a tissue adhesive. Moreover, due to the hydrogen bond-mediated adhesion mechanism, the adhesive can be removed on-demand using a specific solution after wound healing. This biocompatible, highly adhesive, and detachable hydrogel holds significant potential for clinical wound dressing applications.