alpha-cyclodextrin and azobenzene

Locally administrable drugs with controllable release on external cues hold great promise for antitumor therapy. Here, we report an injectable, supramolecular hydrogel (SHG), where the drug release can be controllably driven by near infrared (NIR) irradiation. The SHGs are formed by electrostatic interactions with LAPONITE® (XLG), in which upconverting nanoparticles (UCNPs) modified with α-cyclodextrin (α-CD) are used as the core, and azobenzene quaternary ammonium salts (E-azo) are further assembled through host-guest interactions. The hydrogel demonstrates reversible phase transition between gel and sol states and photothermal conversion capability. In detailed in vitro and vivo trials, drug-loaded SHGs successfully suppressed invasion by cancer cells. Phase transitions that are regulated by NIR light and promote drug release using photothermal effects, highlighting the considerable potential of supramolecular hydrogels in anticancer therapies, especially for treatments requiring long-term, on-demand drug supply in clinics.

Topics: alpha-Cyclodextrins; Animals; Antineoplastic Agents; Azo Compounds; Doxorubicin; Drug Carriers; Drug Liberation; Female; Humans; Hydrogels; Infrared Rays; Lanthanoid Series Elements; Luminescent Agents; Metal Nanoparticles; Mice, Inbred BALB C; Mice, Nude; Neoplasms; Optical Imaging; Phase Transition; Photothermal Therapy; Quaternary Ammonium Compounds; Silicon Dioxide; Static Electricity

The supramolecular construction of multi-stimuli assemblies is a challenging task for prospective use. In this work, a novel supramolecular amphiphile was fabricated by introducing molecules with dynamic covalent bonds into host-guest inclusion. The amphiphile formed a vesicle, which was characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), 1H NMR and UV-vis spectra. Furthermore, the vesicular structure could be regulated by pH, light and redox reagent, and thus the loaded dye in the vesicles could be released in a controlled manner.

Topics: alpha-Cyclodextrins; Azo Compounds; Carbocyanines; Delayed-Action Preparations; Drug Compounding; Drug Liberation; Fluorescent Dyes; Hydrogen-Ion Concentration; Kinetics; Light; Oxidation-Reduction; Pyrenes; Surface-Active Agents

A thermo-, photo- and chemoresponsive shape-memory material is successfully prepared by introducing α-cyclodextrin (αCD) and azobenzene (Azo) into a poly(acrylate acid)/alginate (PAA/Alg) network. The tri-stimuli-responsive formation/dissociation of αCD-Azo acts as molecular switches freezing or increasing the molecular mobility. The resulting film herein can be processed into temporary shapes as needed and recovers its initial shape upon the application of light irradiation, heating, or chemical agent independently. Furthermore, the agar diffusion test suggests that the α-CD-Alg/Azo-PAA has good biocompatibility for L929 fibroblast-like cells.

Topics: Acrylic Resins; Alginates; alpha-Cyclodextrins; Animals; Azo Compounds; Biocompatible Materials; Cell Line; Cell Survival; Fibroblasts; Glucuronic Acid; Hexuronic Acids; Hot Temperature; Hydrogels; Light; Mice

A three-component supramolecular hybrid system based on host-guest recognition and electrostatic interaction has been developed for a consecutive chiral transfer from an alpha-cyclodextrin to cationic dyes via the bridge of a new azobenzene-grafted Anderson-type polyoxometalate cluster.

Topics: alpha-Cyclodextrins; Azo Compounds; Cations; Coloring Agents; Methylene Blue; Spectrophotometry, Ultraviolet; Static Electricity; Stereoisomerism; Tungsten Compounds

The formation of effective and precise linkages in bottom-up or top-down processes is important for the development of self-assembled materials. Self-assembly through molecular recognition events is a powerful tool for producing functionalized materials. Photoresponsive molecular recognition systems can permit the creation of photoregulated self-assembled macroscopic objects. Here we demonstrate that macroscopic gel assembly can be highly regulated through photoisomerization of an azobenzene moiety that interacts differently with two host molecules. A photoregulated gel assembly system is developed using polyacrylamide-based hydrogels functionalized with azobenzene (guest) or cyclodextrin (host) moieties. Reversible adhesion and dissociation of the host gel from the guest gel may be controlled by photoirradiation. The differential affinities of α-cyclodextrin or β-cyclodextrin for the trans-azobenzene and cis-azobenzene are employed in the construction of a photoswitchable gel assembly system.

Topics: alpha-Cyclodextrins; Azo Compounds; beta-Cyclodextrins; Circular Dichroism; Dimethyl Sulfoxide; Gels; Hydrogels; Kinetics; Light; Magnetic Resonance Spectroscopy; Materials Testing; Models, Chemical; Nitriles; Photochemistry; Polymers; Spectrophotometry, Infrared; Ultraviolet Rays; Water

The development of stimulus-responsive polymeric materials is of great importance, especially for the development of remotely manipulated materials not in direct contact with an actuator. Here we design a photoresponsive supramolecular actuator by integrating host-guest interactions and photoswitching ability in a hydrogel. A photoresponsive supramolecular hydrogel with α-cyclodextrin as a host molecule and an azobenzene derivative as a photoresponsive guest molecule exhibits reversible macroscopic deformations in both size and shape when irradiated by ultraviolet light at 365 nm or visible light at 430 nm. The deformation of the supramolecular hydrogel depends on the incident direction. The selectivity of the incident direction allows plate-shaped hydrogels to bend in water. Irradiating with visible light immediately restores the deformed hydrogel. A light-driven supramolecular actuator with α-cyclodextrin and azobenzene stems from the formation and dissociation of an inclusion complex by ultraviolet or visible light irradiation.

Topics: alpha-Cyclodextrins; Artificial Organs; Azo Compounds; Hydrogels; Light; Muscle Contraction; Muscle, Skeletal; Polymers

Topics: alpha-Cyclodextrins; Animals; Azo Compounds; DNA; Light; Macromolecular Substances; Molecular Structure; Spermine

In this study, photoswitchable microcapsules were fabricated based on host-guest interactions between α-cyclodextrin (α-CD) and azobenzene (Azo). Carboxymethyl dextran-graft-α-CD (CMD-g-α-CD) and poly(acrylic acid) N-aminododecane p-azobenzeneaminosuccinic acid (PAA-C(12)-Azo) were assembled layer by layer on CaCO(3) particles. α-CD-rhodamine B (α-CD-RhB), used as a model drug, was loaded on PAA-C(12)-Azo layers by host-guest interaction. After removal of CaCO(3) particles by ethylenediaminetetraacetic acid (EDTA), hollow microcapsules loaded with α-CD-RhB were obtained. Since the interactions between α-CD and Azo were photosensitive, the capsules could be dissociated with the irradiation of UV light, followed by the release of the model drug, α-CD-RhB. Compared with traditional drug-loading approaches such as chemical bonding and physical adsorption, our supramolecular drug-loading system has a facile loading process, ideal bonding strength, and photoswitchable behavior. These photosensitive microcapsules exhibit great potential in biomedical applications.

Topics: Acrylic Resins; alpha-Cyclodextrins; Azo Compounds; Calcium Carbonate; Capsules; Dextrans; Drug Carriers; Photolysis; Rhodamines; Ultraviolet Rays

Two Janus [2]rotaxanes, 5a and 5b, with α-cyclodextrin (α-CD) derivatives substituted on the 6-position with two recognition sites (azobenzene and heptamethylene (C7)) that were linked with linkers of different lengths (oligo(ethylene glycol) with a degree of polymerization equal to 2 or approximately 21) were synthesized and characterized. 2D ROESY NMR spectroscopy and circular dichroism (cd) spectra demonstrated that the recognition site of the α-CD moiety was switched by photoisomerization of the azobenzene moiety in 5a and 5b. The different size changes of 5a and 5b in hydrodynamic radius (R(H)) owing to the different length of linker between two recognition sites were observed by pulse-field-gradient spin-echo NMR spectroscopy. The kinetic results indicated that the different length of linker had no or a weak effect for the photoisomerization process of 5a and 5b.

Topics: alpha-Cyclodextrins; Azo Compounds; Circular Dichroism; Ethylene Glycol; Isomerism; Kinetics; Magnetic Resonance Spectroscopy; Rotaxanes

Herein, photo-controlled inclusion and exclusion reaction of azobenzene-containing polydiacetylene vesicles with alpha-cyclodextrin were used to act as driving force to induce chromatic transition of PDA vesicles, which provided a novel model system that combines photochemistry and host-guest chemistry for a photo-stimulus-responsive vesicle.

Topics: alpha-Cyclodextrins; Azo Compounds; Membranes, Artificial; Models, Biological; Molecular Structure; Photochemistry; Polyacetylene Polymer; Polymers; Polyynes

Topics: alpha-Cyclodextrins; Azo Compounds; Kinetics; Mass Spectrometry; Photochemistry; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry, Ultraviolet; Stereoisomerism; Surface-Active Agents

Azobenzene-functionalized nanotubes recognized and attached onto well-defined complementary regions of thiolated alpha-CD SAM/Au substrates via host-guest molecular recognition. The binding between the azobenzene nanotubes and the alpha-CD SAM/Au substrates was controlled by UV irradiation. The light-induced attachment-detachment of the azobenzene nanotubes on the alpha-CD SAMs was reversible. Some of the nanotubes were capable of interconnecting two Au substrates. This smart building block may be applied to build photoactive nanometer-sized mechanical switches in electronics.

Topics: alpha-Cyclodextrins; Azo Compounds; Cyclodextrins; Ethers, Cyclic; Gold; Hydrogen Bonding; Macrocyclic Compounds; Nanotechnology; Peptides; Photochemistry; Phthalic Acids; Spectrophotometry, Ultraviolet