Mechanochromic cyclodextrins

A water-soluble cationic [2]biphenyl-extended pillar[6]arene: synthesis, host-guest interaction with hemin and application in chemodynamic/photodynamic cancer therapy

A water-soluble cationic [2]biphenyl-extended pillar[6]arene (CBpExP6) was designed and synthesized successfully. It could form a stable 1 : 1 complex with hemin, thereby enhancing the stability of hemin in water, and can be further applied in cancer CDT and PDT.

Unveiling cyclodextrin conjugation as multidentate excipients: An exploratory journey across industries

The discovery of branched molecules like dextrin by Schardinger in 1903 marked the inception of cyclodextrin (CD) utilization, catalyzing its journey from laboratory experimentation to widespread commercialization within the pharmaceutical industry. CD, a cyclic oligosaccharide containing glucopyranose units, acts as a versatile guest molecule, forming inclusion complexes (ICs) with various host molecules. Computational studies have become instrumental in elucidating the intricate interactions between β-CD and guest molecules, enabling the prediction of binding energy, forces, affinity, and complex stability. The computational approach has established robust correlations with experimental outcomes, enhancing our understanding of CD-mediated complexation phenomena. This comprehensive review delves into the CD based Inclusion complex (CDIC) formation and a myriad of components, including drug molecules, amino acids, vitamins, and volatile oils. These complexes find applications across diverse industries, ranging from pharmaceuticals to nutraceuticals, food, fragrance, and beyond. In the pharmaceutical realm, β- CDICs offer innovative solutions for enhancing drug solubility, stability, and bioavailability, thus overcoming formulation challenges associated with poorly water-soluble drugs. Furthermore, the versatility of CDs extends beyond pharmaceuticals, with applications in the encapsulation of phytoactive compounds in nutraceuticals and the enhancing flavor, aroma in food and fragrance industries. This review underscores the pivotal role of CDs conjugation in modern drug delivery systems, emphasizing the importance of interdisciplinary approaches that integrate computational modeling with experimental validation. As the pharmaceutical landscape continues to evolve, CDs-based formulations stand poised to drive innovation and address the ever-growing demand for efficacious and patient-friendly drug delivery solutions.

Asymmetric Cyclodextrin-Dimer-Involved Nanoassemblies by Selective Host-Guest Interactions: Concentration-Dependent Morphology Evolution and Light-Regulated Biomedical Applications

Supramolecular assembly has attracted significant attention and has been applied to various applications. Herein, a β-γ-CD dimer was synthesized to complex different guest molecules, including single-strand polyethylene glycol (PEG)-modified C60 (PEG-C60), photothermal conversion reagent (IR780), and dexamethasone (Dexa), according to the complexation constant-dependent specific selectivity. Spherical or cylindrical nanoparticles, monolayer or bilayer vesicles, and bilayer fusion vesicles were discovered in succession if the concentration of PEG-C60 was varied. Moreover, if near-infrared light was employed to irradiate these nanoassemblies, the thermo-induced morphological evolution, subsequent cargo release, photothermal effect, and singlet oxygen (1O2) generation were successfully achieved. The in vitro cell experiments confirmed that these nanoparticles possessed excellent biocompatibility in a normal environment and achieved superior cytotoxicity by light regulation. Such proposed strategies for the construction of multilevel structures with different morphologies can open a new window to obtain various host-guest functional materials and achieve further use for disease treatment.

Prospects of charged cyclodextrins in biomedical applications

Cyclodextrins (CDs), recognized for their unique ability to form inclusion complexes, have seen broad utilization across various scientific fields. Recently, there has been a surge of interest in the use of charged cyclodextrins for biomedical applications, owing to their enhanced properties, such as superior solubility and improved molecular recognition compared to neutral CDs. Despite the growing literature, a comprehensive review of the biomedical utilisations of multi-charged cyclodextrins is scarce. This review provides a comprehensive exploration of the emerging prospects of charged cyclodextrin-based assemblies in the field of biomedical applications. Focusing on drug delivery systems, the review details how charged CDs enhance drug solubility and stability, reduce toxicity, and enable targeted and controlled drug release. Furthermore, the review highlights the role of charged CDs in gene therapy, notably their potential for DNA/RNA binding, cellular uptake, degradation protection, and targeted gene delivery. The promising potential of charged CDs in antibacterial and antiviral therapies, including photodynamic therapies, biofilm control, and viral replication inhibition, is discussed. Concluding with a future outlook, this review highlights the potential challenges and advancements that could propel charged CDs to the forefront of biomedicine.

Reversible dynamic optical sensing based on coumarin modified β-cyclodextrin for glutathione in living cells

Coumarin acting as an optical probe was modified on ethylenediamine β-cyclodextrin, which not only enhanced its molecular binding affinity to glutathione (GSH) by a reversible Michael addition, showing 113 times more affinity than that of coumarin itself, but also achieved dynamic real-time sensing of glutathione in living HeLa cells.

Construction and Property Investigation of Serial Pillar[5]arene-Based [1]Rotaxanes

Although the construction and application of pillar[5]arene-based [1]rotaxanes have been extensively studied, the types of stoppers for them are limited. In this work, we designed and prepared three series of pillar[5]arene-based [1]rotaxanes (P5[1]Rs) with pentanedione derivatives, azobenzene derivatives, and salicylaldehyde derivatives as the stoppers, respectively. The obtained P5[1]Rs were fully characterized by NMR (1H, 13C, and 2D), mass spectra, and single-crystal X-ray analysis. We found that the synergic C-H···π, C-H···O interactions and N-H···O, O-H···N hydrogen bonding are the key to the stability of [1]rotaxanes. This work not only enriched the diversity of pillar[n]arene family but also gave a big boost to the pillar[n]arene-based mechanically interlocked molecules.

Multicharged cyclodextrin supramolecular assemblies

Multicharged cyclodextrin (CD) supramolecular assemblies, including those based on positively/negatively charged modified mono-6-deoxy-CDs, per-6-deoxy-CDs, and random 2,3,6-deoxy-CDs, as well as parent CDs binding positively/negatively charged guests, have been extensively applied in chemistry, materials science, medicine, biological science, catalysis, and other fields. In this review, we primarily focus on summarizing the recent advances in positively/negatively charged CDs and parent CDs encapsulating positively/negatively charged guests, especially the construction process of supramolecular assemblies and their applications. Compared with uncharged CDs, multicharged CDs display remarkably high antiviral and antibacterial activity as well as efficient protein fibrosis inhibition. Meanwhile, charged CDs can interact with oppositely charged dyes, drugs, polymers, and biomacromolecules to achieve effective encapsulation and aggregation. Consequently, multicharged CD supramolecular assemblies show great advantages in improving drug-delivery efficiency, the luminescence properties of materials, molecular recognition and imaging, and the toughness of supramolecular hydrogels, in addition to enabling the construction of multistimuli-responsive assemblies. These features are anticipated to not only promote the development of CD-based supramolecular chemistry but also contribute to the rapid exploitation of these assemblies in diverse interdisciplinary applications.