A Supramolecular Assembly of EGCG for Long-Term Treatment of Allergic Rhinitis.

Allergic rhinitis (AR) is a type-I hypersensitivity disease mediated by immunoglobulin E (IgE). Although antihistamines, glucocorticoids, leukotriene receptor antagonists, and other drugs are widely used to treat AR, the various adverse side effects of long-term use of these drugs should not be ignored. Therefore, more effective and safe natural alternative strategies are urgently needed. To this end, this study designed a nanosupramolecular delivery system composed of ß-cyclodextrin supramolecular polymer (PCD), thiolated chitosan (TCS), and natural polyphenol epigallocatechin gallate (EGCG) for intranasal topical continuous treatment of AR. The TCS/PCD@EGCG nanocarriers exhibited an excellent performance in terms of retention and permeability in the nasal mucosa and released the vast majority of EGCG responsively in the nasal microenvironment, thus resulting in the significantly high antibacterial and antioxidant capacities. According to the in vitro model, compared with free EGCG, TCS/PCD@EGCG inhibited mast cell activity and abnormal histamine secretion in a more long-term and sustained manner. According to the in vivo model, whether in the presence of continuous or intermittent administration, TCS/PCD@EGCG substantially inhibited the secretion of allergenic factors and inflammatory factors, mitigated the pathological changes of nasal mucosa, alleviated the symptoms of rhinitis in mice, and produced a satisfactory therapeutic effect on AR. In particular, the therapeutic effect of TCS/PCD@EGCG systems were even superior to that of budesonide during intermittent treatment. Therefore, the TCS/PCD@EGCG nanocarrier is a potential long-lasting antiallergic medicine for the treatment of AR.

Double-Layer Hydrogel with Glucose-Activated Two-Stage ROS Regulating Properties for Programmed Diabetic Wound Healing.

Slow healing of wounds induces great pain in diabetic patients. However, developing new approaches to promote diabetic wound healing is still one of the toughest challenges in the medical field. Here, we constructed a new double-layer hydrogel to effectively regulate reactive oxygen species (ROS) on the wound and promote diabetic wound healing. The inner layer contains glucose oxidase (Gox), ferrocene-modified quaternary ammonium chitosan (Fc-QCs), and poly(ß-cyclodextrin) (Pß-CD), which is used to generate hydroxyl radicals (•OH) for antibacterial in the early stage of wound healing and collapses gradually. The outer layer is composed of gelatin and dopamine. In the later stage of wound healing, the outer layer contacts the skin, which is beneficial for ROS clearance on the wound. Antibacterial, ROS scavenging, and wound healing experiments have shown that the double-layer hydrogel possesses two-stage ROS regulating properties for programmed diabetic wound healing. In conclusion, it will be one of the most potential dressings for treating diabetic wounds in the future.

The expression levels of circulating miR-140-3p, miR-130a-3p, and miR-320b as diagnostic biomarkers in acute ischemic stroke.

Plasma miRNAs can characterize several diseases, including acute ischemic stroke (AIS), which is noninvasive and currently affordable in most laboratories worldwide. We aimed to demonstrate plasma miR-140-3p, miR-130a-3p, and miR-320b as diagnostic biomarkers in AIS.GSE110993 and GSE86291 datasets were analyzed to obtain plasma differentially expressed miRNAs between AIS and healthy control subjects (HCs). We further applied RT-qPCR for the validation in 85 AIS patients and 85 HCs. Receiver operating characteristic (ROC) curve were conducted to evaluate their diagnostic utility in AIS. Correlation was analyzed between DEmiRNAs and clinical and laboratory parameters, as well as inflammatory markers. The plasma levels of miR-140-3p, miR-130a-3p, and miR-320b were found to be consistently altered in both GSE110993 and GSE86291 datasets. In comparison to HCs, AIS patients at admission exhibited lower levels of miR-140-3p and miR-320b and higher level of miR-130a-3p in their plasma. The ROC analysis revealed that plasma miR-140-3p, miR-130a-3p, and miR-320b had area under the curve values of 0.790, 0.831, and 0.907, respectively. When combined, these miRNAs showed superior discriminatory power with a sensitivity of 91.76% and specificity of 95.29%. Plasma miR-140-3p and miR-320b negatively correlated glucose levels and inflammatory markers (IL-6, MMP-2, MMP-9, and VEGF) in AIS patients. Conversely, plasma miR-130a-3p levels were positively associated with glucose levels and these markers. Plasma miR-140-3p, miR-130a-3p, and miR-320b levels varied significantly among AIS patients with different NIHSS scores. Plasma miR-140-3p, miR-130a-3p, and miR-320b had high diagnostic value in AIS patients, which were correlated with inflammation and severity in stroke.

Cyclodextrin Metal-Organic Framework as a Broad-Spectrum Potential Delivery Vehicle for the Gasotransmitters.

The important role of gasotransmitters in physiology and pathophysiology suggest employing gasotransmitters for biomedical treatment. Unfortunately, the difficulty in storage and controlled delivery of these gaseous molecules hindered the development of effective gasotransmitters-based therapies. The design of a safe, facile, and wide-scale method to delivery multiple gasotransmitters is a great challenge. Herein, we use an ultrasonic assisted preparation γ-cyclodextrin metal organic framework (γ-CD-MOF) as a broad-spectrum delivery vehicle for various gasotransmitters, such as SO2, NO, and H2S. The release rate of gasotransmitters could be tuned by modifying the γ-CD-MOF with different Pluronics. The biological relevance of the exogenous gasotransmitters produced by this method is evidenced by the DNA cleavage ability and the anti-inflammatory effects. Furthermore, the γ-CD-MOF composed of food-grade γ-CD and nontoxic metal salts shows good biocompatibility and particle size (180 nm). Therefore, γ-CD-MOF is expected to be an excellent tool for the study of co-delivery and cooperative therapy of gasotransmitters.

Poly ß-Cyclodextrin/Quaternary Ammoniated Chitosan Cryogel with a Porous Structure for Effective Hemostasis.

Uncontrolled bleeding is one of the most important causes threatening human health, but quick hemostasis remains a challenge. We prepared porous cryogels with poly ß-cyclodextrin (Pß-CD) and quaternary ammoniated chitosan (QCs). Pß-CD acts as a "water-grabbing agent" to assist QCs' ability to absorb and concentrate blood rapidly. The rat-tail amputation model and liver injury model exhibited that cryogels had excellent hemostatic performance. Moreover, cryogels showed good antibacterial activity and biocompatibility. Therefore, these cryogels can be used as potential hemostatic materials.

Bioinspired Ultra Tear-Resistant Elastomer with a Slidable Double-Network Structure.

Tear resistance is of vital importance in the fabrication and application of synthetic soft materials. However, the paradox of simultaneously improving the tearing energy and elasticity remains a huge challenge for conventional approaches. Here, inspired by the skin, we successfully constructed an extraordinary tear-resistant, superelastic elastomer by the introduction of nanosized polycyclodextrin into the elastomer network to form a slidable interpenetrate double network structure. The tearing energy of the SDEP elastomer is up to 274 KJ/m2, which is comparable to metals and alloys and increased more than 100 times compared with the chemically cross-linked elastomer. The fracture strain exceeded 3300%, which is hardly achieved by other materials with high tearing energy. This comprehensive improvement of antitearing and super elasticity property was achieved by (i) a slide ring effect to dissipate energy and blunt a crack tip; (ii) straightening and reorientation of the slidable double network to deflect the advancing of a crack tip; (iii) a double network sharing the load. These results provide a novel strategy to fabricate elastic, tear-resistant soft material, which may contribute to the practical application as tear-resistant flexible electronics and irregular-shaped stretchable devices.

Green Synthesis of Indeno[1,2-b]quinoxalines Using ß-Cyclodextrin as Catalyst.

An efficient, mild, and green method was developed for the synthesis of indeno[1,2-b]quinoxaline derivatives via o-phenylenediamine (OPD) and 2-indanone derivatives utilizing ß-cyclodextrin (ß-CD) as the supramolecular catalyst. The reaction can be carried out in water and in a solid state at room temperature. ß-CD can also catalyze the reaction of indan-1,2-dione with OPD with a high degree of efficiency. Compared to the reported methods, this procedure is milder, simpler, and less toxic, making it an eco-friendly alternative. In addition, the ß-CD can be recovered and reused without the loss of activity.

Recent Advances of Porous Materials Based on Cyclodextrin.

Porous materials have attracted significant attention because of their rising applications in many fields. Cyclodextrins (CDs) are suitable building units in the fabrication of porous materials owing to their intrinsic nanoporous structure, easy modification, and biocompatibility, which may result in the formation of CD-based organic frameworks (including cyclodextrin metal-organic frameworks (CD-MOFs) and cyclodextrin covalent organic frameworks (CD-COFs)), and CD-based polymer hybrid porous materials. This review focuses on the recent progress in the fabrication and applications of CD-based porous materials with novel structures and functionalities.

Ultrahigh Carbon Dioxide-Selective Composite Membrane Containing a γ-CD-MOF Layer.

Mixed matrix membranes (MMMs) for CO2 separation have overcome the trade-off between gas permeability and gas selectivity to some extent. However, most MMMs still are prepared in lab- and pilot-scales since the permeability and selectivity of CO2 are not good enough to reach the economically available requirements. Moreover, the fabrication of few MMMs with good separation performance is time-consuming or need harsh conditions. In this study, a novel MOF-based composite membrane (PAN-γ-CD-MOF-PU membrane) was successfully fabricated by a facile and fast spin-coating method. In the two-step coating process, we applied a uniform selective layer of γ-cyclodextrin-MOF (γ-CD-MOF) on porous polyacrylonitrile and then coated a layer of polyurethane on the γ-CD-MOF layer. The entire membrane formation process was about 30 s. The formation of a unique γ-CD-MOF layer greatly improved the separation ability of CO2 (the CO2 permeability is 70.97 barrers; the selectivity to CO2/N2 and CO2/O2 are 253.46 and 154.28, respectively). The gas separation performance can exceed the Robeson upper limit obviously and the selectivity is better than other MOF-based composite membranes. In addition, the PAN-γ-CD-MOF-PU membrane is strong and flexible. Therefore, the PAN-γ-CD-MOF-PU membrane developed in this study has great potential in large-scale industrial separation of CO2.

Facile Fabrication of an AIE-Active Metal-Organic Framework for Sensitive Detection of Explosives in Liquid and Solid Phases.

Nowadays, the practical applications of metal-organic framework (MOF)-based fluorescence detectors are severely hindered because of the complex synthesis process of linkers or heavy metal contamination. The development of a simple, inexpensive, and environmentally friendly fluorescence sensing system remains a huge challenge. In this study, we designed and synthesized a TPE@γ-CD-MOF-K complex using the facile in situ encapsulation method. The unique pore structure of γ-CD-MOF allowed it to effectively include TPE and explosives as guests simultaneously. The TPE@γ-CD-MOF-K showed stronger fluorescence emission than TPE and sensitive fluorescence quenching activities in response to nitro-aromatic compounds in the liquid phase with detection limits as low as 3 ppm. Furthermore, TPE@γ-CD-MOF-K can also effectively detect nitro-aromatic compounds in the solid state, which is very convenient for practical detection of explosives. The unique pore structure of γ-CD-MOF-K and the interaction between K+ and nitro compounds play important roles in solid-state quenching.

Poly (vinyl alcohol)/ß-Cyclodextrin Composite Fiber with Good Flame Retardant and Super-Smoke Suppression Properties.

Fibers with good flame retardant (FR) and smoke suppression performances are highly desirable for the purpose of eliminating fire hazard. This study developed a novel FR fiber by wet-spinning poly (vinyl alcohol)/ß-cyclodextrin (PVA/ßCD) composite fiber and crosslinking it with hexamethylene diisocyanate (HDI). ßCDs showed good compatibility with PVA matrix, and the resulting PVA/CD/HDI fibers showed mechanical strength at the same level as natural cotton fiber. The PVA/CD/HDI fibers also showed excellent flame retardance (the LOI value of PVA/CD/HDI could reach 41.7%, and their peak of heat release (PHRR) could be reduced by up to 77.7% by neat PVA), and super-smoke suppression (the value of total smoke production (TSP) was only 28.6% compared to PVA). These dramatic reductions of fire hazard were ascribed to the char formation of ßCD and crosslinking structure of PVA/CD/HDI, which formed a compact char layer during combustion, thus preventing heat transmission and smoke release.

Amino-Functionalized ß-Cyclodextrin to Construct Green Metal-Organic Framework Materials for CO2 Capture.

The adsorption of CO2 by conventional liquid alkanolamine adsorbents does not meet the requirements for green-friendly development in industrial applications. In this work, we constructed NH2-ß-CD-MOF for the first time through the amino-functionalization of the lowest-priced, readily available, and biocompatible ß-CD. Subsequently, the samples were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, elemental analysis, and N2 adsorption/desorption. The CO2 adsorption capacity of NH2-ß-CD-MOF was found to be 12.3 cm3/g, which is 10 times that of ß-CD-MOF. In addition, NH2-ß-CD-MOF has outstanding selective adsorption of CO2/N2 (947.52) compared with the reported materials. The adsorption mechanism of CO2 was analyzed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Furthermore, we have found that NH2-ß-CD-MOF has better water stability relative to ß-CD-MOF and γ-CD-MOF, and it can be recycled by an ultrasonic method.

Functional materials with self-healing properties: a review.

Self-healing materials (SHMs) have been a research hot topic in recent years owing to their greatly improved longevity and safety in practical applications. Recently, research on SHMs has gradually expanded from structural materials to functional materials. Functional materials with self-healing properties (FMSH) require simultaneous repairing not only of the mechanical properties but of the functionalities from damaged cracks or wounds. It is more challenging to introduce both self-healing properties and a particular functionality to materials owing to the difficulties of preparing the materials and their more complex healing mechanism. Herein, we summarize the recent progress that has been made in FMSH, put forward insights from the perspectives of material preparation and healing mechanisms and highlight future developments for FMSH.

Tough Self-Healing Elastomers Based on the Host-Guest Interaction of Polycyclodextrin.

Inspired by animal muscles, we developed a kind of tough elastomers combining high strength and high stretchability with autonomous self-healing capability. A key structural feature is the construction of a double network (DN) connected by the hydrogen bond and host-guest interactions. The first network is the classic elastomer polyacrylate matrix cross-linked by strong hydrogen bonding. The second network is formed through the host-guest interactions between polycyclodextrin and the adamantane (Ad) groups on the side of the polyacrylate chain. Supramolecular interactions between two networks make them miscible and interpenetrate in the molecular level and then can share the load as the sample was stretched. The host-guest interactions act not only as sacrificial bonds for energy dissipation but also as self-healing driving forces. The tensile strength of the DN elastomer reaches about 6.7 MPa and the strain is as high as about 950%. The DN elastomer can be easy to repair by touching the damaged surface together at ambient conditions when broken or cut. The recovered tensile strength can reach over 4.5 MPa, which is better than the most pristine strength of existing spontaneous self-healing elastomers.

ß-Cyclodextrin based air filter for high-efficiency filtration of pollution sources.

Airborne particulate matter (PM) pollution has become a serious environmental problem. Thus, there is a need for the development of air filters with satisfactory overall performance. In this paper, we develop a kind of ß-cyclodextrin (ß-CD) based air filter with high strength, which has not only high filtration efficiency (about 99%) but also good air permeability (the pressure drop is only 45Pa). Especially after long-term application, the pression drop of ß-cyclodextrin based was less than half of the commercial air-filter. Additionally, the material can capture the toxic gasous chemicals (e.g. formaldehyde and SO2). The introduction of ß-CD is supposed to be the key factor for improvement of air filter.

Facile stabilization of a cyclodextrin metal-organic framework under humid environment via hydrogen sulfide treatment.

Increasing resistance to humid environments is a major challenge for the application of γ-CD-K-MOF (a green MOF) in real-world utilisation. γ-CD-K-MOF-H2S with enhanced moisture tolerance was obtained by simply treating MOF with H2S gas. XPS, Raman and TGA characterizations indicated that the H2S molecules coordinated with the metal centers in the framework. H2S acting as a newly available water adsorption potential well near the potassium centers protects the metal-ligand coordination bond from attack by water molecules and thus improves the moisture stability of MOF. After 7 days exposure in 60% relative humidity, γ-CD-K-MOF-H2S retained its crystal structure and morphology, while γ-CD-K-MOF had nearly collapsed. In addition, the formaldehyde uptake tests indicated that γ-CD-K-MOF retain their permanent porosity after interaction with H2S. This simple and facile one-step strategy would open a new avenue for preparation of moisture stable MOFs for practical applications.

Leeches-Inspired Hydrogel-Elastomer Integration Materials.

Inspired by the functions of leeches, for the first time homogeneous materials integrating hydrogels and elastomers were achieved by free radical polymerization. 2-Methoxyethyl acrylate (MEA) was used as elastomer monomer and Pluronics functionalized with vinyl groups acted as cross-linkers to impart the hydrogel property to the materials. The resulting Pluronic/PMEA gels possess a swelling ratio of about 210% and good water-retaining ability. Compression tests of Pluronic/PMEA gels at swelling equilibrium state show a stress up to 1.6 MPa under 85% strain. The gels act as elastomer after dehydration. Uniaxial tensile fracture stress and the elongation reached 1200 kPa and 500%, respectively, and compression stress was above 22 MPa. Furthermore, the Pluronic/PMEA gels also show self-healing properties. Owing to the excellent mechanical performance in both wet and dry conditions, this hydrogel-elastomer integrated material may have potential applications in tissue engineering, soft robotics, and biomedical devices.

Super Tough, Ultrastretchable Hydrogel with Multistimuli Responsiveness.

The research of hydrogels has been increasingly focused on designing an effective energy dissipation structure in recent years. Here, we report a kind of novel supramolecular cross-linker, which was formed by self-assembling amphiphilic block copolymers with guest groups at the end and vinyl-functionalized cyclodextrin (CD) through host-guest interaction. These cross-linkers could dissipate energy effectively since they combined multiple sacrificial mechanisms across multiscales through physical interactions. The resulted hydrogel shows distinguishing mechanical properties (fracture toughness of 2.68 ± 0.69 MJ/m3, tension strength of up to 475 kPa, uniaxial stretch over 2100%), remarkable fatigue resistance, and thermal- and light-responsive behaviors.

Effective Formaldehyde Capture by Green Cyclodextrin-Based Metal-Organic Framework.

A kind of metal-organic framework made from γ-cyclodextrin (γ-CD) and potassium ions were explored as excellent formaldehyde (HCHO) absorbents. The adsorption capacity and speed of γ-CD-MOF-K are both about 9 times higher than those of activated carbon, which are attributed to the porous structure and synergistic effect of hydrogen bonding and host-guest interactions.

Reusable Xerogel Containing Quantum Dots with High Fluorescence Retention.

Although various analytical methods have been established based on quantum dots (QDs), most were conducted in solution, which is inadequate for storage/transportation and rapid analysis. Moreover, the potential environmental problems caused by abandoned QDs cannot be ignored. In this paper, a reusable xerogel containing CdTe with strong emission is established by introducing host⁻guest interactions between QDs and polymer matrix. This xerogel shows high QDs loading capacity without decrease or redshift in fluorescence (the maximum of loading is 50 wt % of the final xerogel), which benefits from the steric hindrance of ß-cyclodextrin (ßCD) molecules. Host⁻guest interactions immobilize QDs firmly, resulting in the excellent fluorescence retention of the xerogel. The good detecting performance and reusability mean this xerogel could be employed as a versatile analysis platform (for quantitative and qualitative analyses). In addition, the xerogel can be self-healed by the aid of water.