Biomacromolecule‐Fueled Transient Volume Phase Transition of a Hydrogel

Abstract

A metabolic cycle-inspired hydrogel which exhibits the biomacromolecule-fueled transient volume phase transition is reported. This hydrogel has the affinity and digestive capacity for a fuel α-poly-L-lysine by incorporating acrylic acid and trypsin. The hydrogel captured fuel and transiently shrank owing to the construction of electrostatic cross-linkages. This process was inherently connected with the digestion of these cross-linkages and the release of oligo-lysine as waste, which induced the reswelling of the hydrogel at equilibrium. The transient volume change of the hydrogel realized the fuel-stimulated transient release of a payload. This study provides a strategy for engineering materials with biomacromolecule-fueled dynamic functions under the out-of-equilibrium condition.

Bioinspired Self-Resettable Hydrogel Actuators Powered by a Chemical Fuel

“…In recent years, scientists have coupled chemical fuel-regulated nonequilibrium CRNs to molecular self-assembly − and dynamic cross-linking of hydrophilic polymers, − giving rise to various active hydrogel materials that show fuel-controlled autonomous hydrogelation behaviors. Very recently, Walther’s and Matsusaki’s groups have further extended this concept to enable transient volume-phase transitions of hydrogels, adding a step to the development of autonomous hydrogel actuators, although these systems suffer from serious deteriorations caused by the accumulation of wastes or slow response speed (days). Despite these advances, so far, autonomous hydrogel actuators driven by a chemical fuel remain scarce.…”

Bio‐Inspired Far‐From‐Equilibrium Hydrogels: Design Principles and Applications

“…In addition to degrade the structure of the building blocks by the enzymes, another strategy involves the degradation of the fuel to achieve the desired dissipation effect. In 2022, Matsusaki's group [121] reported a polymer hydrogel that exhibits transient volume phase transition fuelled by biomacromolecules α‐poly‐L‐lysine (PL), which is accompanied by the destruction of PL cross‐linkers via acrylamide trypsin (AcTryp)‐caused digestion, Figure 3C–D. The hydrogel was fabricated through copolymerization of acrylamide (AAm), N,N’‐methylenebisacrylamide (BIS), acrylic acid (AAc), acrylamide trypsin (AcTryp), and acrylamide fluorescein (AFA).…”

“…Taking advantages of transient stiffness changes or volume changes of obtained hydrogels, one can envision that the timed and autonomous release of drugs, and more accurately release at desired position could be achieved. Recently, Matsusaki and co‐workers [121] developed a biomacromolecule (polylysine)‐fuelled transient polyacrylamide gel that exhibited a bulk phase transition, which allows for temporal drug release, as described in section 3.1.1, Figure 3C–F. In this case, methylene blue was selected as model molecules and loaded in the hydrogel.…”

Engineering metabolic cycle-inspired hydrogels with enzyme-fueled programmable transient volume changes

“…53 Most recently, the engineering of a metabolic-cycle-inspired hydrogel exhibiting the biomacromolecule-fueled transient volume phase transition (TVPT) has been demonstrated. 54 In this system, the hydrogel with affinity and digestive capacity for α-poly- l -lysine afforded TVPT and transient release of payload under the out-of-equilibrium condition upon fuel feeding.…”