Biobased Stimuli-Responsive Hydrogels That Comprise Supramolecular Interpenetrating Networks and Exhibit Programmed Behaviors

In this paper, a hierarchical design of supramolecular hydrogels comprising two individual supramolecular networks that are capable of exhibiting reversible and programmed behaviors is described. Both component networks are established by (i) conformational transformation of natural polysaccharides and (ii) host-guest interaction between separate polymer chains. Sequential formation of each orthogonal network generates an interpenetrated structure, which results in the formation of biobased, completely noncovalent, double-network hydrogels. Owing to the intrinsic advantages of the cross-linking system, the hydrogel materials demonstrated the reversibility of physical properties in response to heat or light and exhibited macroscopic performance such as self-healing or injectable properties without calamitous structural collapse. In particular, it was possible to demonstrate the superstructured hydrogels as a responsive vector. Selected dye or drug molecules were loaded during the formation of the networks, and sustained release behavior was achieved around body temperature, which could be fairly enhanced upon UV-light irradiation. Also, we were able to develop a three-dimensional, bioprinted, large-scale pattern using the hydrogels as a bioink. We envisage that the designed hydrogels can be further advanced by employing other cargo molecules or supramolecular chemistries, which would create emerging, autonomous materials suitable for bioengineered scaffolds or coating layers that are implantable and highly sensitive to physiological signals.