Multicolor luminescent supramolecular hydrogels based on cucurbit[8]uril and OPV derivative

Preparation and Biomedical Applications of Cucurbit[n]uril-Based Supramolecular Hydrogels

The cucurbit[n]uril supramolecular hydrogels are driven by weak intermolecular interactions, of which exhibit good stimuli responsiveness and excellent self-healing properties. According to the composition of the gelling factor, supramolecular hydrogels comprise Q[n]-cross-linked small molecules and Q[n]-cross-linked polymers. According to different driving forces, hydrogels are driven by the outer-surface interaction, the host-guest inclusion interaction, and the host-guest exclusion interaction. Host-guest interactions are widely used in the construction of self-healing hydrogels, which can spontaneously recover after being damaged, thereby prolonging their service life. The smart Q[n]s-based supramolecular hydrogel composed is a kind of adjustable and low-toxicity soft material. By designing the structure of the hydrogel or modifying the fluorescent properties, etc., it can be widely used in biomedicine. In this review, we mainly focus on the preparation of Q[n]-based hydrogels and their biomedical applications including cell encapsulation for biocatalysis, biosensors for high sensitivity, 3D printing for potential tissue engineering, drug release for sustained delivery, and interfacial adhesion for self-healing materials. In addition, we also presented the current challenges and prospects in this field.

A stimuli-responsive pillar[5]arene-based hybrid material with enhanced tunable multicolor luminescence and ion-sensing ability

Tunable luminescent materials are becoming more and more important owing to their broad application potential in various fields. Here we construct a pillar[5]arene-based hybrid material with stimuli-responsive luminescent properties and ion-sensing abilities from a pyridine-modified conjugated pillar[5]arene and a planar chromophore oligo(phenylenevinylene) upon coordination of Cd (II) metal cores. This new material not only shows an optimized luminescence due to the minimized π-π stacking and efficient charge transfer properties benefitting from the existence of pillar[5]arene rings, but also exhibits tunable multicolor emission induced by different external stimuli including solvent, ions and acid, indicating great application potential as a fluorescent sensory material, especially for Fe3+. With this pillar[5]arene-based dual-ligand hybrid material, valid optimization and regulation on the fluorescence of the original chromophore have been achieved, which demonstrates a plausible strategy for the design of tunable solid-state luminescent materials and also a prototypical model for the effective regulation of fluorescent properties of planar π systems using synthetic macrocycle-based building blocks.

Cucurbit[8]uril-based supramolecular hydrogels for biomedical applications

As a member of the cucurbit[n]uril family (where n denotes the number of glycoluril units), cucurbit[8]uril (CB[8]) possesses a large cavity volume and is able to accommodate two guests simultaneously. Therefore, CB[8] has been adapted as a dynamic noncovalent crosslinker to form various supramolecular hydrogels. These CB[8]-based hydrogels have been investigated for various biomedical applications due to their good biocompatibility and dynamic properties afforded by host-guest interactions. In this review, we summarize the hydrogels that have been dynamically fabricated via supramolecular crosslinking of polymers by CB[8] reported during the past decade, and discuss their design principles, innovative applications in biomedical science and their future prospects.

Adhesion enhancement via the synergistic effect of metal–ligand coordination and supramolecular host–guest interactions in luminescent hydrogels

We report an approach to achieve adhesion enhancement via the synergistic effect of metal–ligand coordination and supramolecular host–guest interactions in luminescent hydrogels without affecting their luminescence behavior.