Bioinspired Tough and Antiswelling Hydrogel via in Situ Self-Assembly of Amphiphilic Copolymers within a Hydrophilic Network

Inspired by tropoelastin coacervation, a process in elastic fiber formation driven by hydrophobic interactions, we developed a tough, antiswelling hydrogel, PHEA-(PVA-<i>co</i>-PE), by incorporating amphiphilic poly(vinyl alcohol-<i>co</i>-ethylene) (PVA-<i>co</i>-PE) into a hydrophilic poly(2-hydroxyethyl acrylate) (PHEA) network. The PHEA-(PVA-<i>co</i>-PE) hydrogel was prepared by UV-induced polymerization of a PHEA precursor dimethyl sulfoxide (DMSO) solution containing PVA-<i>co</i>-PE, followed by immersion in water. During solvent exchange, PVA-<i>co</i>-PE self-assembled into micellar structures within the PHEA matrix, mimicking the coacervation of tropoelastin. Compared with PHEA and PVA-<i>co</i>-PE hydrogels, the strength of PHEA-(PVA-<i>co</i>-PE) increased by 83 and 7 times, while the toughness increased by 145 and 97 times. This strategy can be further extended to a variety of amphiphilic copolymers, demonstrating the universality. In vitro and in vivo tests demonstrated that the hydrogel possesses excellent biocompatibility and antiswelling capability. This study provides a simple method for developing a tough, biocompatible, and antiswelling hydrogel.