Reversible morphological tuning of DNA–perylenebisdiimide assemblies through host–guest interaction

A new supramolecular host–guest strategy is developed to reversibly control the morphology of DNA–perylenebisdiimide assemblies in aqueous solution.

Cucurbit[8]uril-Based Polymers and Polymer Materials

Cucurbit[8]uril (CB[8]) is unique and notable in the cucurbit[n]uril family, since it has a relatively large cavity and thus is able to simultaneously accommodate two guest molecules. Typically, an electron-deficient first guest and an electron-rich second guest can be bound by CB[8] to form a stable 1:1:1 heteroternary supramolecular complex. Additionally, two homo guests can also be strongly dimerized inside the cavity of CB[8] to form a 2:1 homoternary supramolecular complex. During the past decade, by combining polymer science and CB[8] host-guest chemistry, a variety of systems have been established to construct supramolecular polymers with polymer chains typically at the nanoscale/sub-microscale, and CB[8]-based micro/nanostructured polymer materials in the form of polymer networks and hydrogels, microcapsules, micelles, vesicles, and colloidal particles, normally in solution and occasionally on surfaces. This Review summarizes the noncovalent interactions and strategies used for the preparation of CB[8]-based polymers and polymer materials with a focus on the representative and latest developments, followed by a brief discussion of their characterization, properties, and applications.

Supramolecular Interfacial Polymerization: A Controllable Method of Fabricating Supramolecular Polymeric Materials

A new method of supramolecular polymerization at the water-oil interface is developed. As a demonstration, an oil-soluble supramonomer containing two thiol end groups linked by two ureidopyrimidinone units and a water-soluble monomer bearing two maleimide end groups are employed. Supramolecular interfacial polymerization can be implemented by a thiol-maleimide click reaction at the water-chloroform interface to obtain supramolecular polymeric films. The glass transition temperature of such supramolecular polymers can be well-tuned by simply changing the polymerization time and temperature. It is highly anticipated that this work will provide a facile and general approach to realize control over supramolecular polymerization by transferring the preparation of supramolecular polymers from solutions to water-oil interfaces and construct supramolecular materials with well-defined properties.

Supramolecular Hydrogels Fabricated from Supramonomers: A Novel Wound Dressing Material

Daily repeated wound dressing changes will lead to additional trauma to newly formed tissue and prolonging the healing process. In this letter, we designed and fabricated an easily removable wound dressing material. To accomplish this, we first generated cross-linkable supramonomers through host-guest noncovalent interaction, followed by radical copolymerization of acrylamide with supramonomer as cross-linker to fabricate supramolecular hydrogels. Benefiting from the dynamic nature of the supramonomer, the supramolecular hydrogel is able to dissolve upon exposure to memantine, an FDA approved drug, making it easily removed from a wound, representing a promising candidate for the new generation of wound dressing.

ABx-type amphiphilic macromonomer-based supramolecular hyperbranched polymers for controllable self-assembly

A novel supramolecular hyperbranched polymer (SHP) is constructed through using an AB_x-type amphiphilic macromonomer. The obtained SHP can form ellipsoidal unimolecular micelles and branched aggregates under different solution conditions.

UV light- and thermo-responsive hierarchical assemblies based on the inclusion complexation of β-cyclodextrin and azobenzene

UV- and thermo-responsive hierarchical assemblies consisting of an umbrella-shaped supramolecular polymer have been achieved based on the inclusion complexation between β-cyclodextrin and azobenzene.

Controllable Supramolecular Polymerization Promoted by Host-Enhanced Photodimerization

In this letter, we report a new method of controllable supramolecular polymerization, taking advantage of host-enhanced photodimerization. The low-molecular-weight supramolecular oligomers were formed by noncovalent complexation between cucurbit[8]urils (CB[8]) and the bifunctional monomers (DBN) with Brooker's merocyanine moiety (MOED) on either end. Interestingly, when irradiated with UV light, the supramolecular oligomers could transform into supramolecular polymers with high molecular weight. The molecular weight of supramolecular polymers could be controlled by varying the irradiation time. It is highly anticipated that this work can enrich the methods on the modulation of supramolecular polymerization.

Supramolecular Microgels Fabricated from Supramonomers

This letter describes a new method for fabricating supramolecular microgels from supramonomers. To this end, we designed and assembled supramonomers with one acrylate moiety on each end on the basis of noncovalent host-guest interactions, which could be utilized as a cross-linker. Then supramolecular microgels were fabricated through the copolymerization of supramonomers and N-isopropylacrylamide (NIPAm). The supramolecular microgels not only showed temperature-responsive properties as expected from conventional PNIPAm-based microgels but also exhibited stimuli-responsive and degradable properties benefiting from the dynamic nature of supramonomers. In addition, it was found that the degradation kinetics of the supramolecular microgels was related greatly to the structure of the microgels, providing a way to tune the degradation kinetics of the supramolecular microgels. Various supramolecular microgels with desired structure and function are supposed to be facilely fabricated from supramonomers. It is anticipated that the supramolecular microgels can enrich the application of microgels by easily endowing the microgels with stimuli-responsive and degradable properties.

Controllable supramolecular polymerization through self-sorting of aliphatic and aromatic motifs

Self-sorting is one of the effective strategies to realize control over supramolecular polymerization.

Photo-responsive supramolecular polymers synthesized by olefin metathesis polymerization from supramonomers

This communication reports the construction of photo-responsive supramolecular polymers that are synthesized by olefin metathesis polymerization from quadruple hydrogen bonded supramonomers.

Controllable Supramolecular Polymerization through Host-Guest Interaction and Photochemistry

A new method for controllable supramolecular polymerization based on ABBA type monomer and cucurbit[8]uril monomer through host-guest interaction and photochemistry is reported. The molecular weight and polydispersity of supramolecular polymers can be well controlled by tuning the molar ratio of these host and guest monomers or by tuning the isomer ratio of azobenzene groups in the guest monomers upon the competitive irradiation of lights. This research provides a general methodology for the control of supramolecular polymerization and the structure of supramolecular polymers.

Light-triggered capture and release of DNA and proteins by host-guest binding and electrostatic interaction

The development of an effective and general delivery method that can be applied to a large variety of structurally diverse biomolecules remains a bottleneck in modern drug therapy. Herein, we present a supramolecular system for the dynamic trapping and light-stimulated release of both DNA and proteins. Self-assembled ternary complexes act as nanoscale carriers, comprising vesicles of amphiphilic cyclodextrin, the target biomolecules and linker molecules with an azobenzene unit and a charged functionality. The non-covalent linker binds to the cyclodextrin by host-guest complexation with the azobenzene. Proteins or DNA are then bound to the functionalized vesicles through multivalent electrostatic attraction. The photoresponse of the host-guest complex allows a light-induced switch from the multivalent state that can bind the biomolecules to the low-affinity state of the free linker, thereby providing external control over the cargo release. The major advantage of this delivery approach is the wide variety of targets that can be addressed by multivalent electrostatic interaction, which we demonstrate on four types of DNA and six different proteins.

Amphiphilic diselenide-containing supramolecular polymers

This communication describes the fabrication of diselenide-containing supramolecular polymers.

Supramolecular polymers synthesized by thiol–ene click polymerization from supramonomers

This communication describes supramolecular polymers fabricated by thiol–ene click polymerization from supramonomers.

Supramolecular polymers bearing disulfide bonds

Supramolecular polymers bearing disulfide bonds have successfully been fabricated by combining dynamic covalent bonds with host–guest chemistry.