Tough Wet Adhesion of Hydrogen-Bond-Based Hydrogel with On-Demand Debonding and Efficient Hemostasis

Abstract

Hydrogels have been widely used in wet tissues. However, the insufficient adhesion of hydrogels for wound hemostasis remains a grand challenge. Herein, a facile yet effective strategy is developed to fabricate tough wet adhesion of hydrogen-bond-based hydrogel (PAAcVI hydrogel) using copolymerization of acrylic acid and 1-vinylimidazole in dimethyl sulfoxide followed by solvent exchange with water. The PAAcVI hydrogel shows equally robust adhesion (>400 J m–2) to both wet and dry tissues. Moreover, the PAAcVI hydrogel also exhibits strong long-term stable adhesion underwater and in various wet environments. Meanwhile, the adhesion of PAAcVI hydrogel can be adjusted through Zn2+-ion-mediated on-demand debonding, which makes it easy to peel off from the tissue reducing pain during dressing removal and avoiding secondary injury. The PAAcVI hydrogel displays efficient hemostasis in the mice-tail docking model and mice-liver bleeding model. This hydrogen-bond-based hydrogel shows tough wet adhesion, and its adhesion is controllable, demonstrating its promising application in moisture-resistant adhesives, medical adhesives, and hemostatic materials.

Wet-Adhesive Multifunctional Hydrogel with Anti-swelling and a Skin-Seamless Interface for Underwater Electrophysiological Monitoring and Communication

“…For instance, heart attacks have risen to the second ranking cause of death for divers, which makes aquatic electrocardiogram (ECG) monitoring crucial before a heart attack occurs . Nevertheless, conventional adhesive hydrogels that are applied in a dry environment are not suitable for adhesion in these aquatic conditions because water prevents direct contact between the sensor and the skin. − Moreover, because of the instability of the polymer backbone and the unrestrained diffusion of conductive ions in aqueous environments, it ultimately leads to deterioration in the mechanical and electrical performances of hydrogels (e.g., structural collapse, swelling, and electroconductive degradation). , Despite that a number of hydrogels designed for biomedical applications (e.g., wound dressing and hemostatic agents) with wet/underwater adhesion capability have been reported, − most of their electrical conductivity, especially long-term stability, has not been fully explored. To achieve reliable long-term physiological signal acquisition in aquatic conditions, it becomes a prerequisite to design and synthesize novel hydrogels with high electrical conductivity, long-term stable underwater adhesion, and conformal contact with skin.…”

Self-healing, self-adhesive, stretchable and flexible conductive hydrogels for high-performance strain sensors

“…Recently, a booming development in the preparation of multifunctional hydrogels with self-healing and self-adhesion properties for strain sensors has been observed. Both reversible covalent bonds such as in Schiff-bases, 18 borates, 19 and disulfides 20,21 and non-covalent interactions including hydrogen bonds, 22 ion interactions, 23 metal coordination, 24 host-guest interactions, 25 hydrophobic interactions 26 and p-p stacking interactions 27 can endow hydrogels with self-healing performance. For example, Yao et al designed a semiinterpenetrating ionic conductive hydrogel by introducing cellulose nanofibers (CNFs) into a phenylboronic acid ionic liquid/ acrylamide crosslinked network.…”

Urea as a Hydrogen Bond Producer for Fabricating Mechanically Very Strong Hydrogels

“…Hydrogen bonding also plays a very important role in the construction and stabilization of natural and synthetic polymeric materials. − As a typical example, cellulose, the most abundant natural biomacromolecule with huge potential applications, is cross-linked by very strong cooperative hydrogen bonds between the hydroxyl groups of neighboring chains . However, on the other hand, the presence of strong hydrogen bonds in natural polymers strongly hinders their practical applications.…”