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Highlights: [•] A fenspiride/β-CD complex was prepared and characterized in detail. [•] An enzyme-responsive assembly system was constructed. [•] The system included reversible control of formation and disruption of vesicles. [ABSTRACT FROM AUTHOR]

Just as biological behaviors that can be tuned by salt ions, salt-containing soft materials are of great importance in various fields. Here we report a supramolecular cyclodextrin gel, of which properties including gelation behavior, fiber size, thermal stability as well as mechanical strength could be well tailored by inorganic salts. The concentrations, types of alkali salts were tested and had a profound impact on the gel properties. The formation/collapse behaviors and variations of gel fiber size were characterized through scanning electron microscopy (SEM), transmission electron microscopy (TEM) and optical microscopy (OM). Infrared spectroscopy (IR), differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS) revealed the mechanism of molecular arrangement and provided insight into the outstanding salt effects. This might have potential applications in designing novel smart materials and provide a new course of constructing multi-morphological gels by salts. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes an instant-formative organogel triggered by small organic molecules (cogelators) at a high temperature. The system was prepared by β-cyclodextrin (β-CD) and lithium chloride (LiCl) in N, N-dimethyl acetamide (DMAc). Under stirring, a clear solution is obtained at 120–130°C and transformed into a gel phase within several seconds once the cogelators are injected. The gelling times (GT) distribution of more than 1min to no more than 1s, which can be mediated by the concentration of cogelators. When beyond the certain concentration, cogelators can gel the system instantly which GT even cannot be precisely observed (below 1s). Numerous kinds of short alkyl chain aliphatic molecules were studied as cogelators for the first time, which cover a broad range including acid, ketone, alcohol etc. Scanning electron microscopy (SEM) measurements revealed that the three-dimensional micromorphology were diverse corresponding to different functional groups of cogelators. The X-ray diffraction (XRD) measurement proves that the self-assembled mode of gel was head-to-head channel-type. Fourier transform infrared spectroscopy (FT-IR) measurement evidences the formation of intermolecular hydrogen bonds. The molecular dynamics simulation was performed to obtain the mechanism of the formation of the gel, and the result is consistent with the experimental phenomenon. We believe the specific properties of the gel may bring up a novel application of the supramolecular gel. [Copyright &y& Elsevier]

Curcumin is a safe and nontoxic natural potential antitumor drug. However, its extremely low aqueous solubility severely limits its clinical application. We designed a supramolecular curcumin vesicle based on different curcumin-cyclodextrin amphiphiles, which could greatly enhance the aqueous solubility of curcumin up to 7000-fold. The vesicles can exist for about one month in aqueous solution at around 20 °C, showing a certain colloidal stability. The curcumin-β-cyclodextrin vesicles were identified by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and dynamic light scattering (DLS). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–vis spectrum and 1 H NMR were further employed to study the formation mechanism of the vesicles. Curcumin vesicles were also prepared when different host molecules were employed as the hydrophilic heads of the supramolecular amphiphiles. Finally, curcumin could be controllably released with the disruption of the vesicles when the external stimuli, including competitive guest molecules, enzymes and copper ions were added into the vesicles system. [ABSTRACT FROM AUTHOR]

Highlights: [•] The supramolecular vesicles constructed by cyclodextrin–ftorafur supramolecular amphiphiles are reported. [•] The mechanism of the vesicles formation was studied by various methods. [•] The effect of copper ions on the vesicles was discussed. [•] The antitumor effects of the ftorafur-loaded vesicles on human colon carcinoma cell lines HT-29 were studied in detail. [Copyright &y& Elsevier]

Abstract: This paper describes the first example of controllable transformation from sensitive and reversible heat-set organogel to stable gel induced by sodium acetate. Upon the addition of proper amount of acetate sodium into the reversible heat-set organogel system composed of β-CD, phenolphthalein (PP) and lithium chloride in N,N-dimethylformamide, the reversible gel could transform to stable gel as the temperature decreased. Further studies showed that other analogous acetates with K+ and Mg2+ do not possess this property. The gel was characterized by SEM, XRD and FT-IR. This work may pave the way for the design of smart materials with multi-responsiveness. [Copyright &y& Elsevier]

Abstract: This paper describes a novel heat-set organogel transformation which could be triggered by lithium chloride (LiCl) from precipitate for the first time. The system was prepared with β-cyclodextrin (β-CD) and triphenylphosphine (Ph3P) in N,N-dimethylformamide (DMF). The system as an original transparent solution at room temperature could turn into precipitation by heating. Subsequently, the precipitation turned into organogel instantly based on the injection of LiCl into the system. SEM measurement revealed that the precipitate and gel systems have different microstructures. IR and XRD measurements revealed that the inclusion complexes formed by β-CDs and Ph3P were arranged in cage structures in the precipitate and channel structures in the gel. Molecular dynamics simulations were performed both on the formation of the precipitate and gel models in this system, which were consistent with the test results. [Copyright &y& Elsevier]