Design of Adhesive Hemostatic Hydrogels Guided by the Interfacial Interactions with Tissue Surface

Abstract

Adhesive hemostatic hydrogels, as one of the most important wound dressings, have attracted tremendous attention because of their unique advantages in injured tissue. Many intensive efforts are devoted to designing ingenious adhesive hemostatic hydrogels based on interfacial interactions with tissue surfaces, such as covalent bonds, hydrogen bonds, electrostatic interactions, cation–π interactions, and π–π stacking interactions. Herein, an overview of the recent progress in adhesive hemostatic hydrogels is provided, especially focusing on diverse covalent/noncovalent interfacial interactions between the active groups of adhesive hydrogels and tissue surface. The commonly used forms and the hemostatic evaluation models of the adhesive hydrogels are also summarized. Finally, the critical issues that should be concerned for current adhesive hemostatic hydrogels and the developing directions toward practical applications are discussed.

Injectable, Shear-Thinning, Self-Healing, and Self-Cross-Linkable Benzaldehyde-Conjugated Chitosan Hydrogels as a Tissue Adhesive

“…56 Similarly, the adhesion between the hydrogel and the underlying tissue is also facilitated by Schiff base linkages, π−π stacking, and hydrogen bonding. 57 However, electrostatic interactions play a minor role in promoting adhesion because of the limited number of protonated amine groups. On the other hand, under mildly acidic conditions (pH 4−6), the interactions within the hydrogel would decrease due to partial hydrolysis of the Schiff base linkages.…”

“…Additionally, there is a certain contribution from π–π stacking between the benzene rings and hydrogen bonding . Similarly, the adhesion between the hydrogel and the underlying tissue is also facilitated by Schiff base linkages, π–π stacking, and hydrogen bonding . However, electrostatic interactions play a minor role in promoting adhesion because of the limited number of protonated amine groups.…”

Functional hemostatic hydrogels: design based on procoagulant principles

“…Hydroxyl groups can interact chemically with amino groups or amide bonds in tissues and enhance the adhesion of hydrogels. 99 The hydroxyl groups in starch, cellulose, and HA are abundant. Two phenolic acids that are abundant in nature are protocatechuic acid (PA) and glyoxylic acid (GA), with GA having one more hydroxyl group than PA in its structure.…”

“…Hydrogel adhesion to a bleeding wound is the most common way to achieve it. 98,99 Many materials improve adhesion. 32,[100][101][102] Tissue sealing requires the hydrogel to have the ability to adapt to different shapes.…”

“…Therefore, it is necessary to control the phenolic hydroxyl group oxidation. 99 Hydrogel adhesion is improved by catechol, a benzene derivative with two adjacent phenolic groups. Metal ions bind with catechol, improving mechanical characteristics.…”