Highly Stretchable, Tough, Resilient, and Antifatigue Hydrogels Based on Multiple Hydrogen Bonding Interactions Formed by Phenylalanine Derivatives

Abstract

Noncovalent cross-linked hydrogels with promising mechanical properties are on demand for applications in tissue engineering, flexible electronics, and actuators. However, integrating excellent mechanical properties with facile preparation for the design of hydrogen bond cross-linked hydrogels is still challenging. In this work, an advanced hydrogel was prepared from acrylamide and N-acryloyl phenylalanine by one-pot free-radical copolymerization. Owing to hydrophobicity-assisted multiple hydrogen bonding interactions among phenylalanine derivatives, the hydrogels exhibited fascinating mechanical behaviors: tensile strength of 0.35 MPa, elongation at break of 2100%, tearing energy of 1134 J/ m 2 , and compression strength of 3.56 MPa. The hydrogels also showed robust elasticity and fatigue resistance, and the compression strength did not show any decline, even after 100 successive cycles, as well as promising self-recovery property. In addition, the cytotoxicity test in vitro proved that the hydrogel showed good biocompatibility with normal human liver cells (LO2 cells). The excellent stretchability, robust elasticity, high toughness, fatigue resistance, and biocompatibility of the hydrogel demonstrated its vast potential in the biomedical field and flexible electronic devices.

Preparation of Fucoidan-Based Electrospun Nanofibers and Their Interaction With Endothelial Cells

“…Besides the biochemical properties, their biophysical structure can significantly mediate cell attachment, shape, viability, the differentiation or pluripotency of stem cells, and even tissue repair and regeneration ( Li et al, 2018 ; Cui et al, 2020 ; Yu et al, 2020 ; Yu et al, 2021 ; Zhou et al, 2020 ; Liu et al, 2021 ; Yang et al, 2021a ; Yang et al, 2021b ). Recently, the development of nanofibrous materials has received increasing attention in tissue engineering and regenerative medicine due to their outstanding properties, such as their favorable biological properties, sufficient mechanical strength, highly porous mesh with interconnectivity, extremely high specific surface area, and aspect ratio ( Zhou et al, 2015 ; Zhou et al, 2017 ; Kenry and Lim, 2017 ; Xue et al, 2019 ; Ahmadi et al, 2021 ).…”

Robust hydrogel adhesives for emergency rescue and gastric perforation repair

“…For comparison, three bi-carboxyl-included acrylamide monomers, AGLU (glutamic acid derivative), AASP (aspartic acid derivative), and AAMI, were synthesized with minor modifications to the previously described method [ 32 ]. The 1 H NMR spectra shown in Figs.…”

“…As the basic structural unit of proteins, amino acids play a vital role in the formation of the secondary structure of protein through hydrogen bonds. It has been reported that amino acid derivatives, which can form intermolecular multiple hydrogen bond interactions, have the advantage of constructing hydrogels with comprehensive mechanical properties after being introduced into polymer design [ 31 , 32 ]. Owing to the presence of carboxyl groups on amino acids, the resulting hydrogels also present the potential as adhesives.…”

A self-powered flexible sensing system based on a super-tough, high ionic conductivity supercapacitor and a rapid self-recovering fully physically crosslinked double network hydrogel

“…However, most double network hydrogels are prepared by chemical crosslinking to form three-dimensional networks, leading to the poor self-recovery and fatigue resistance of hydrogels. [16][17][18][19][20] The covalent bond of such hydrogels easily causes irreversible damage when they have large deformations. To address this problem, the most common strategy is to introduce reversible physical bonds (such as hydrogen bonds, [21][22][23] hydrophobic associations, 24,25 ion complexation, 26,27 and polymer chain entanglement 28,29 ) into two networks to synthesize fully physically crosslinked double network hydrogels.…”