Search Results (409)

Polydiacetylene (PDA) nanovesicles are widely recognized as versatile chromatic sensing platforms, exhibiting a visible blue-to-red colorimetric transition in response to external stimuli such as temperature, pH, and molecular recognition events. In contrast to the conventional goal of amplifying this chromatic response, this work presents a supramolecular approach to inhibit the α-cyclodextrin (α-CD)-induced colorimetric transition in PDA systems. α-CD is known to interact with PDA vesicles through host–guest inclusion at the vesicle interface, triggering the characteristic chromatic change. Here, we show that the incorporation of an EO–PO–EO triblock copolymer (L64) into PDA suspensions enables controlled modulation of the α-CD-induced chromatic response, leading to a progressive attenuation of the blue-to-red transition as the L64 concentration increases. Isothermal titration calorimetry reveals a stronger affinity of α-CD for L64 (K = 11,300) than for PDA vesicles (K = 4000), with both interactions being spontaneous (ΔG° ≈ −21 kJ mol⁻¹) and predominantly entropy-driven. Copolymer aggregation and phase separation occur without compromising the PDA vesicles, indicating that the observed chromatic modulation arises from supramolecular competition. This study introduces a strategy to regulate PDA affinity chromism using biocompatible triblock copolymers, offering a tunable and robust pathway for the design of responsive and safe chromatic sensing platforms. Full article

The rational design of mixed micellar systems has emerged as a cornerstone of modern nanomedicine, offering unprecedented control over the solubility and bioavailability of challenging therapeutic agents. This review provides a comprehensive analysis of the physicochemical principles governing the assembly of amphiphilic drugs and surfactants into synergistic nanostructures. By articulating the transition from traditional guest/host solubilization to “drug-as-component” models, we highlight the critical role of molecular interactions in achieving therapeutic precision. It further outlines the experimental methodologies used to investigate these systems and elucidates how they enhance the solubility, stability, and bioavailability of poorly water-soluble drugs. Special emphasis is placed on the practical applications of synergy in reducing systemic toxicity and optimizing drug release kinetics, providing a roadmap for the development of next-generation nano-pharmaceuticals. The functionality of these systems is significantly influenced by the molecular interactions among their constituents; thus, quantitative analysis of these interactions might enhance the formulation of more effective pharmaceuticals. This review outlines the key physicochemical principles of mixed micelle formation, including thermodynamics and synergistic interactions of amphiphiles, while emphasizing their relevance in current research and practical pharmaceutical applications. Various experimental methods, such as surface tension measurement, conductometric and calorimetric tests, and spectroscopic techniques, are compared in terms of their conditions of application and performance in understanding micelle formation and micelle structure. We clearly point out that the interpretation and evaluation of the properties of colloidal systems containing drug molecules solubilized by mixed micelles and an amphiphilic drug incorporated into micelles must be discussed and evaluated separately. Understanding the limitations and characteristics of the physical/chemical principles applied is essential for the rational design of mixed micelle carriers tailored to specific therapeutic needs. Full article

Background/Objectives: Ursodeoxycholic acid (UDCA) is a bile acid widely used for the treatment of cholestatic liver diseases; however, its poor aqueous solubility represents a major limitation for the development of oral liquid formulations, particularly in pediatric patients requiring accurate and flexible dosing. This study aimed to develop and characterize a fully solubilized extemporaneous UDCA oral formulation using the ready-to-use vehicle Wagner, with particular emphasis on the role of hydroxypropyl-β-cyclodextrin (HP-β-CD) as a solubilizing excipient. Methods: Phase-solubility studies, Job’s plot analysis, and ¹H NMR spectroscopy were performed to investigate the host–guest interaction between UDCA and HP-β-CD, confirming the formation of a stable 1:1 inclusion complex responsible for a marked increase in drug solubility. The aqueous solubility of UDCA increased from approximately 0.02 mg/mL in water to 31 ± 1 mg/mL in the Wagner base containing HP-β-CD, compared to ~10 mg/mL in the corresponding cyclodextrin-free vehicle. Chemical stability was evaluated using an HPLC method adapted from the European Pharmacopoeia, employing dual detection (refractive index and photodiode array detector) to ensure specificity and stability-indicating capability. Results: The UDCA solution (20 mg/mL) remained chemically stable for at least 4 months under refrigerated (4–8 °C) and room temperature (25 °C) conditions, with only moderate degradation observed at 40 °C. Physical stability studies confirmed the absence of precipitation, phase separation, or significant pH variations under all storage conditions. Conclusions: Wagner-based formulation enabled the development of a stable and homogeneous UDCA oral solution, providing a complementary formulation strategy to conventional suspension-based preparations. This approach represents a robust and patient-oriented strategy for extemporaneous compounding, particularly suitable for pediatric use. Full article

Here, we present a general statistical-mechanical model able to reconstruct the temperature dependence of the thermodynamic properties of non-covalent host–guest inclusion complexes using a set of molecular dynamics simulations along an isobar. Our approach, applied to $\beta$-cyclodextrin in interaction with E- and Z-dimethomorph as well as a bisphenol A derivative, provides a robust description of the in silico data, able to well reproduce the host–guest binding thermodynamics at every temperature. Full article

Negative online reviews play a critical role in shaping consumer decision-making in the hospitality sector. Drawing on cue utilization theory and signaling theory, this study examines how different types of negative reviews and host responses affect potential guests’ booking intentions, as well as the underlying mechanisms and boundary conditions. Across three scenario experiments, the proposed framework was tested. Study 1 reveals a significant interaction between the type of negative reviews (informational vs. social) and host response strategies (problem-focused vs. emotion-focused), highlighting that aligning response strategies with review types is critical for effective negative review management. Study 2 demonstrates that perceptions of host competence and attitude mediate these effects, indicating that potential guests make decisions through psychological inference. Study 3 finds that platform-endorsed credibility signals, such as host badges (Superhost vs. non-Superhost), significantly moderate these relationships. When hosts are Superhosts, informational negative reviews paired with problem-focused responses further enhance competence perceptions and booking intentions; for non-Superhosts, social negative reviews paired with emotion-focused responses improve attitude perceptions and booking intentions. The findings advance theoretical understanding of how signaling mechanisms shape consumer behavior in home-sharing hospitality platforms, and offer practical guidance for hosts and platforms to manage online reputations strategically and effectively. Full article

Self-healing materials have attracted increasing attention as a strategy to enhance durability, extend service life, and reduce maintenance in advanced material systems. Among these, cellulose-based self-healing materials represent a sophisticated intersection between sustainable macromolecular chemistry and adaptive materials science. This review provides a synthesis of recent advancements in the field, systematically categorizing materials derived from cellulose raw materials. We evaluate the fundamental chemical strategies employed to achieve autonomous repair, distinguishing between extrinsic mechanisms—utilizing cellulose-based micro/nano-capsules to sequester healing agents—and intrinsic mechanisms governed by dynamic covalent chemistry (Schiff-base, boronic ester, Diels–Alder) and supramolecular interactions (hydrogen bonding, metal–ligand coordination, and host–guest assemblies). The analysis highlights how cellulose’s hierarchical structure and abundant surface functionality are leveraged to overcome the traditional trade-off between mechanical toughness and healing efficiency. Particular emphasis is placed on the transition from simple structural hydrogels to sophisticated multifunctional systems. These include ultra-stretchable strain and pressure sensors for e-skin applications, biocompatible and injectable matrices for chronic wound management and stem cell delivery, and advanced anti-freezing eutectogels for performance in extreme environments. Furthermore, we explore the integration of cellulose into traditional sectors, such as self-healing concrete utilizing microbe-induced calcification and smart, eco-friendly coatings for corrosion protection. Finally, we discuss critical challenges, including environmental stability, scalability, and the development of standardized evaluation protocols, providing a roadmap for the next generation of bio-derived, sustainable and intelligent materials. Full article

The increasing prevalence of drug-resistant microorganisms has prompted research into novel antimicrobial compounds, with 2-thiophene carboxylic acid thiourea derivatives showing promise for future therapeutic applications. However, the poor water solubility of these compounds limits their practical use. This study investigates the formation and characterization of inclusion complexes between 2-hydroxypropyl-β-cyclodextrin (HPβCD) and 2-thiophene carboxylic acid-halogenated (chlorine-, bromine-, and iodine-) thiourea derivatives, seeking to improve their physicochemical properties. The dynamic light scattering (DLS) measurements and UV-Vis spectroscopy provided information related to thiourea–HPβCD aggregates and stoichiometry. Solid-state inclusion compounds and physical mixtures were prepared in two different molar ratios (thioureas:HPβCD = 1:1 and 1:2), and the morphology of the resulting powders was observed by scanning electron microscopy (SEM). Thermogravimetry (TG) and differential scanning calorimetry (DSC) (TG-DSC) coupled analysis were used to analyze thermal profiles in the temperature range of 25 °C to 600 °C, while the spectral data obtained by Fourier transform infrared spectroscopy (FTIR) provided the characteristic vibrational bands of the pure guest molecules and data corresponding to the structural and chemical changes in the host–guest systems. The structural and thermal analyses revealed significant interactions between the host and thioureas molecules, with evidence of possible interactions involving two cyclodextrin molecules. The results demonstrate the presence of intermediate stoichiometry in the inclusion compounds, with possible enhancement of the therapeutic potential of these thiourea derivatives. Full article

This study explores the formation of inclusion complexes between a newly synthesized N-(2-(butylamino)-2-oxoethyl)-2-(3-cyano-4-isobutoxyphenyl)-4-methylthiazole-5-carboxamide with β-cyclodextrin using density functional theory with dispersion correction (DFT-D3) at the B3LYP-GD3/3-21G, 6-31G(d), 6-31G’(d), and 6-311G(d) levels. Two orientations are considered: in Orientation A, the 3-cyano-4-isobutoxyphenyl moiety interacts with the primary hydroxyl rim of β-cyclodextrin, while in Orientation B, the amide side chain faces the wider rim. Complexation energies and thermodynamic parameters are calculated to determine stability. Electronic properties, including HOMO-LUMO energies, and global reactivity descriptors, such as electronegativity (χ), chemical potential (μ), hardness (η), and electrophilicity index (ω), are evaluated. Non-covalent interaction (NCI) analysis is also performed to visualize interaction sites. The results reveal the significant influence of orientation on the host–guest complex stability and electronic properties, providing valuable insights into cyclodextrin-based encapsulation systems. The study provides a computational blueprint for engineering cyclodextrin-based bio-functional systems, where orientation-controlled inclusion governs stability, reactivity, and performance. This can significantly impact the development of smart drug delivery systems, biosensors, and multifunctional biomaterials in modern bioengineering. Full article

This study evaluates β-cyclodextrin (β-CD) and malonic acid functionalized pine sawdust biochar for organic pollutant removal, benchmarking efficacy against commercial Norit GSX activated carbon for sustainable water treatment. Characterization revealed that β-CD modification successfully developed porous structures, with Sawdust Activated Carbon (SDAC) and Norit GSX Activated Carbon (GSXAC) achieving Brunauer–Emmett–Teller (BET) surface areas of 438.36 m²/g and 1223.79 m²/g, respectively. Adsorption kinetics and isotherm studies demonstrated the superiority of β-CD-modified materials over traditional acid-functionalized variants. The adsorption kinetics were exceptionally well-described by the Pseudo-Second-Order model R² > 0.99, indicating that the process is governed by chemical interactions rather than simple physical attachment. In contrast, the Pseudo-First-Order and Elovich models provided poor descriptions of the system (R² = 0.54 and 0.11, respectively). An isotherm analysis further confirmed the heterogeneous nature of the SDAC surface, with the Freundlich model exhibiting an excellent fit (R² > 0.99) and an n value of 0.79. For GSXAC, the Freundlich model also outperformed the Langmuir model, yielding a K_F of 441.72 mg/g and n = 0.77, reflecting high adsorption intensity on a heterogeneous surface. The comparative advantage of β-CD is in line with its unique truncated cone structure, which is consistent with guest–host inclusion complex formation, multi-modal hydrogen bonding, and enhanced pH resilience. These findings validate β-CD-modified sawdust-derived adsorbents as potential, sustainable, high-capacity alternatives to industrial-grade carbons. Full article

Efficient solubilization of nonpolar substances in polar solvents represents a fundamental challenge in environmental remediation, green chemistry, and separation processes. This limitation stems from the hydrophobic effect, which creates thermodynamic barriers, resulting in low intrinsic solubility and strong phase separation. This review examines the thermodynamic basis of solubilization, focusing on free-energy changes and molecular interaction mechanisms. It discusses various strategies, including surface and interface engineering, host–guest inclusion, solvent engineering, and nanostructure encapsulation, along with their practical applications. Future research directions include smart responsive materials, green solvent design theories, and precise construction of solubilization systems through multi-scale simulations. Full article

Thermally activated delayed fluorescence (TADF) emitters doped in host–guest systems are widely utilized for organic light-emitting diodes (OLEDs), where key rate constants and the fluorescence quantum yield (Φ_F) are strongly influenced by the surrounding environment. However, the multifaceted interactions, i.e., dipole–dipole interaction and conformational restraint between the emitter and environment have been rarely investigated systematically, where excited state charge transfer (CT) and structural relaxation (SR) of emitters should be considered equally. In this study, four representative CT–TADF emitters were selected as model systems and studied in PS/PMMA:TADF:CA host–guest doped films with varied dielectric constants and matrix rigidity. Within D–A and D–A–D configurations, donor substitution from PXZ to DMAC varied CT characteristics, whereas TRZ-based D–A and DPS-based D–A–D emitters provided a relative difference in SR owing to their different rigidity. The total reorganization energy (λ_Total) was introduced as a quantitative measure of these multifaceted interactions and correlated with the rate constants. The results indicate that the dielectric dependence of the nonradiative decay rate (k_nr^S) for D–A–D molecules cannot be explained by the simplified energy gap law, where the vibronic effect plays the role of a game changer. This work provides a quantitative framework and highlights vibrational frequency as a key design parameter for optimizing Φ_F in host–guest doped OLED devices. Full article

Hybrid supramolecular–nanocomposite hydrogels based on polyethylene glycol (PEG), β-cyclodextrin–adamantane host–guest interactions, and silica nanoparticles represent an important class of hierarchical soft materials with tunable viscoelastic and transport properties. This review critically analyzes recent progress in cyclodextrin–silica hybrid PEG hydrogels, focusing on the mechanistic coupling between stiffness, stress relaxation, and molecular transport arising from the interplay between reversible supramolecular crosslinks and nanoparticle-induced confinement effects. Particular attention is given to how host–guest exchange kinetics regulate dynamic bond rearrangement and affinity-mediated retention of hydrophobic cargo, while silica nanoparticles enhance mechanical reinforcement and modify diffusion pathways through tortuosity and interfacial polymer–particle interactions. The analysis highlights how nanoparticle size, loading level, and surface functionalization influence relaxation spectra and network topology, as well as how environmental stimuli may affect supramolecular bond stability and overall material performance. Comparison with alternative inorganic fillers and mesoporous silica architectures further clarifies the specific advantages of silica in achieving balanced mechanical stability and controlled transport behavior. Overall, current evidence indicates that hybrid CD–silica networks enable partial decoupling of stiffness, relaxation dynamics, and diffusion, although complete independence remains constrained by fundamental polymer physics relationships. These insights support the development of predictive structure–property frameworks for advanced biomedical and controlled release applications. Full article

This study presents the post-synthetic functionalization of Ni-Co bimetallic nanoparticles (NPs) with a β-cyclodextrin (β-CD) framework using a green synthesis approach with Illicium verum (Star anise) extract. The synthesized nanocomposite was verified using physicochemical characterization techniques such as FTIR, XRD, Zeta potential, DLS, SEM, and TEM. This surface modification successfully yielded a stable core–shell architecture with a reduced crystallite size of 29.5 nm, compared to 41.2 nm for bare Ni-Co NPs. The β-CD coating shifted the Zeta potential from −33.07 mV to −27.65 mV, establishing an electro-steric stabilization mechanism. Sensing performance toward Cd²⁺ ions was evaluated via the QCM-D technique. The Ni-Co/β-CD nanocomposite demonstrated a superior sensitivity of 34.72 Hz/mM and a remarkably low limit of detection (LOD) of 17.3 µM, representing a 27-fold enhancement over the bare Ni-Co NPs (LOD: 472.2 µM). The mechanical signature, characterized by negative dissipation shifts and a high acoustic ratio (ΔD/Δf = 79.410 × 10⁻⁶), confirms an analyte-induced conformational rigidification driven by a host–guest interaction mechanism. These findings establish a robust method of producing bio-based, “smart” nanocomposites for high-precision environmental sensing. Full article

Measurement of material thermodynamic parameters plays a crucial role in understanding the interactions between host materials and guest species. Therefore, developing a general-purpose system for thermodynamic parameter measurement is of great significance. In this work, a complete gas–solid interface thermodynamic parameter measurement platform was developed based on isothermal adsorption and a resonant microcantilever testing platform. Unlike conventional adsorption measurement systems that rely on manual, multi-cycle adsorption–desorption processes, the proposed platform integrates an automated hardware–software architecture together with a stepwise concentration-gradient protocol and on-chip thermal desorption, enabling continuous and efficient acquisition of adsorption isotherms. The study includes: (i) construction of an improved thermodynamic parameter extraction model based on the Sips model, (ii) development of an integrated resonant microcantilever control and acquisition module using a modified Fourier algorithm, and (iii) implementation of an automated testing and data analysis software framework developed in LabVIEW based on the Queued Message Handler (QMH) architecture. The system was validated from both hardware performance and material testing perspectives using CO₂ adsorption on H-SSZ-13 as a representative case. The results show that the system achieves a maximum sampling rate of 10,000 pts (points per second), with minimum root-mean-square (RMS) noise levels of 0.0083 Hz for frequency and 0.0109 °C for temperature. The PID temperature-control settling time (0.1%) is 24.9 ms, and the frequency-response settling time (0.01%) is 9.6 ms. Thermodynamic parameters including entropy change (ΔS), enthalpy change (ΔH), and Gibbs free energy change (ΔG) were successfully extracted during CO₂ adsorption at 294.15 K under different relative uptakes. Reproducibility was verified across three independent samples, yielding a standard deviation of 9.1 J·mol⁻¹ for ΔS at 2% relative uptake and relative standard deviations of 6.85% and 8.12% for ΔH and ΔG, respectively. These results demonstrate that the proposed thermodynamic measurement platform features a simple architecture, superior performance, and high reproducibility in gas–solid interface thermodynamic studies, showing strong potential for future commercialization. Full article

Metal–organic frameworks (MOFs) are unique microporous materials being explored for a wide range of applications. Their porosity and high surface areas can readily be exploited for guest–host interactions, separations, and photochemical catalysis, but many suffer from poor charge separation and fast electron–hole recombination. Introducing structural defects, such as missing linkers or metal nodes, can create unsaturated metal sites and alter band structure, conductivity, and light absorption, improving photocatalytic performance. UiO-66-NH₂ and MIL-125-NH₂ are water-stable, visible-light-absorbing MOFs well suited for photocatalytic degradation of organic dyes. In this work, the influence of defect engineering on photocatalytic properties of MOFs was investigated using formic and acetic acid modulators with UiO-66-NH₂ and variable temperature with MIL-125-NH₂ during synthesis. The resulting materials were characterized by XRD, FTIR and SEM/EDS. Defect states were tracked using N₂ adsorption/BET analysis and UV–Vis spectroscopy. Photocatalytic activity was evaluated by monitoring Rhodamine B (RhB) degradation in aqueous solution under simulated solar irradiation. It was found that increased temperature beyond 120 °C during synthesis promotes mesopore formation and decreases the bandgap in MIL-125-NH₂, resulting in a more photoactive material. Defective MIL-125-NH₂ synthesized at 150 °C showed the most defects and proved to be the best photocatalyst investigated in this study. Formic acid modulation in UiO-66-NH₂ generated smaller crystallites that slightly increased the bandgap; however, the surface area decreased proportionally with the amount of formic acid used. The decreased surface area and observed enhancement in photocatalytic degradation of RhB suggest that formic acid introduces defects into the UiO-66-NH₂ framework that enhance photocatalytic properties. UiO-66-NH₂ treated with acetic acid resulted in larger crystals, increased bandgaps, and increased surface areas, suggesting that acetic acid simply modulates growth rather than imparting defects to the framework. Full article