Fabrication of Bioinspired Hydrogels Using Carboxyphenylboronic Acid-Grafted Polyethylenimine and Polyvinyl Alcohol...

Tissue adhesives are gaining increasing attention as efficient alternatives to conventional wound closure methods, yet their clinical translation is often hindered by insufficient wet adhesion and inadequate biocompatibility. Drawing inspiration from nature's robust wet-adhesion strategies, particularly dynamic covalent interactions and reversible crosslinking, we report a family of bioinspired composite hydrogels fabricated from 4-carboxyphenylboronic acid-grafted polyethylenimine (4-CPBA-PEI) and polyvinyl alcohol (PVA) that serve as versatile bioadhesives. The polyethylenimine with different molecular weights (18,000, 70,000, and 100,000 Da) was used to prepare the 4-CPBA-PEI derivatives via EDC/NHS-mediated amidation. The resulting hydrogels exhibited three-dimensional interconnected porous networks with tunable pore dimensions and equilibrium swelling ratios (ranging from 400% to 700%), closely correlated with the PEI molecular weight. Rheological measurements confirmed typical viscoelasticity, shear-thinning behavior, and outstanding self-healing performance, which are mainly attributed to hydrogen bonds and dynamic borate ester bonds in the network. The hydrogels firmly adhered to the surfaces of diverse matrices, such as glass, rubber, metal, plastic, wood, human skin, and wet mouse organs. Additionally, the obtained hydrogels exhibited high 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging activity (>85%), excellent hemocompatibility (hemolysis rate < 0.5%), and potent intracellular reactive oxygen species (ROS) scavenging activity. Cytocompatibility studies using NIH 3T3 fibroblasts demonstrated low cytotoxicity and favorable cytocompatibility. This biomimetic design yields multifunctional hydrogels that integrate tunable physical properties, wet-surface attachment, self-healing, antioxidant activity, and good biocompatibility, suggesting their potential as wound dressing candidates.