Β-cyclodextrin Molecules Research Articles

Enhancing effect of β-cyclodextrin on carbonation properties of steel slag

In order to improve the carbonation properties of steel slag, the carbonation reaction process of steel slag and the formation of carbonation products were regulated by the interaction between multiple hydroxyl groups within β-cyclodextrin (β-CD) molecule and calcium ions leached from steel slag. Through a meticulous experimental design, varying contents of β-CD, from 0.0 % to 5.0 %, were mixed with steel slag to investigate their impact on carbonation kinetics, mechanical strength, and microstructural evolution. The results indicate that β-CD significantly accelerates the carbonation process of steel slag, with a particular boost to the carbonation of β-dicalcium silicate (β-C2S), a key mineral contributing to the carbonation activity. At an optimal β-CD concentration of 2.5 %, the compressive strength of the treated slag reached a peak of 138.5 MPa, marking a 13.4 % improvement over the control sample. Similarly, the CO2 uptake was optimized at 17.9 %, increasing by 21.8 %. Mechanism analysis reveals that β-CD not only facilitates carbonation but also refines the resulting carbonation products, leading to a denser microstructure and enhanced mechanical properties. However, at a β-CD content of 5.0 %, the carbonation process was hindered by excessive viscosity. These pivotal findings propose an innovative strategy to augment the efficiency of carbonation and the inherent material properties of steel slag, thereby fostering a more sustainable approach to the utilization of industrial byproducts.

Methamphetamine Removal from Aquatic Environments by Magnetic Microrobots with Cyclodextrin Chiral Recognition Elements.

The growing consumption of drugs of abuse together with the inefficiency of the current wastewater treatment plants toward their presence has resulted in an emergent class of pollutants. Thus, the development of alternative approaches to remediate this environmental threat is urgently needed. Microrobots, combining autonomous motion with great tunability for the development of specific tasks, have turned into promising candidates to take on the challenge. Here, hybrid urchin-like hematite (α-Fe2O3) microparticles carrying magnetite (Fe3O4) nanoparticles and surface functionalization with organic β-cyclodextrin (CD) molecules are prepared with the aim of on-the-fly encapsulation of illicit drugs into the linked CD cavities of moving microrobots. The resulting mag-CD microrobots are tested against methamphetamine (MA), proving their ability for the removal of this psychoactive substance. A dramatically enhanced capture of MA from water with active magnetically powered microrobots when compared with static passive CD-modified particles is demonstrated. This work shows the advantages of enhanced mass transfer provided by the externally controlled magnetic navigation in microrobots that together with the versatility of their design is an efficient strategy to clean polluted waters.

Thermodynamics of Sorption of Organic Compounds by Sorbents Based on Supramolecular Liquid Crystal HPFAB and β-Cyclodextrin Derivatives under Gas Chromatography Conditions

Using gas chromatography, we studied the influence of the nature of substituents in the β-cyclodextrin (CD) molecule on the sorption properties and the possibility of complex formation with the macrocycle of 26 organic compounds (hydrocarbons and alcohols) in binary sorbents based on the smectic–nematic supramolecular liquid crystal 4-(3-hydroxypropyloxy)-4'-formylazobenzene (HPOFAB) and four derivatives β-CD. It has been established that the nature of the substituents in the β-CD molecule significantly affects the manifestation of solvation interactions between LC and macrocyclic additive and, as a consequence, the mesomorphic, sorption, and selective properties of the studied composite sorbents.

Cyclodextrin based Nanosponges for the Oral Delivery of Actarit: Physicochemical Characterisation and Dissolution Studies

Introduction: The current research aims to formulate a controlled release formulation of Actarit utilizing cyclodextrin based nanosponges as a nanocarriers. β-Cyclodextrin built nanosponges were prepared by condensation reaction using diphenyl carbonate as crosslinking agent. Method: A 3-level, 3-factor Box-Behnken design was used to optimize the reaction conditions. The particle size, zeta potential and solubilization efficiency of prepared nanosponges were determined. Actarit was loaded into nanosponges by freeze drying method. Actarit loaded nanosponges were further evaluated for particle size, zeta potential, surface morphology, FTIR, DSC, XRD and Dissolution characteristics. The cyclodextrin nanosponges prepared under optimum conditions exhibited a particle size range of 143.42 to 152.76 nm with low polydispersity indices. FTIR spectra confirmed the formation of carbonyl bond between the β-Cyclodextrin molecules. Results and Discussion: Actarit loaded nanosponges exhibited a particle size range of 157.13 to 168.34 nm with minimum polydispersity index. The zeta potential value was sufficiently high to maintain the stability of colloidal nanosponges. TEM image exposed the spherical structure of drug loaded nanosponges that could be retained and released gradually over time. The FTIR, DSC and XRPD studies inveterate the interaction between Actarit and nanosponges. The drug loaded nanosponges displayed a significant progress in dissolution of drug when compared to plain Actarit. The initial rapid release of Actarit from nanosponges formulations was observed. After 24 h of study, around 90 % of the drug released from nanoformulation and only around 20 % of the drug from free drug suspension. Conclusion: Cyclodextrin based nanosponges displayed superior complexing capability with increased solubility of poorly soluble Actarit.

Tetrafluorinated versus hydrogenated azobenzene polymers in water: Access to visible-ligh stimulus at the expense of responsiveness

Photo-responsive polymers are at the core of numerous applications as actuators in biology but often exhibit the drawback of activation in the UV range. This work describes a methacrylate-based terpolymer presenting tetra-ortho-fluoroazobenzene groups showing activation through visible light illumination. The presence of poly(ethylene oxide) side chains and maleimide functions ensures that it can be easily used for biological applications in aqueous media. The terpolymer was shown to form unimolecular micelles in water. The tetra-ortho-fluoroazobenzene moiety was reversibly switched from trans to cis upon visible light irradiation without significant modification of the unimolecular morphology. The deprotection of the maleimide function resulted in a reactive polymer which was used to obtain hydrogels by reaction with poly(ethylene oxide) tetra-thiols or bioconjugates by reaction with a model peptide or a poly(ethylene oxide) mono-thiol exhibiting a biotin group. Hydrogels incorporating β-cyclodextrin molecules were also obtained. Contrary to polymers bearing hydrogenated azobenzenes, the terpolymer bearing tetra-ortho-fluoroazobenzene moieties did not form a complex with β-cyclodextrin and none of the presented hydrogels exhibited macroscopic changes upon irradiation although the trans/cis isomerization occurred. This was explained by the burial of tetra-ortho-fluoroazobenzene groups towards the polymer backbone, therefore completely hindering its access.

PH-Responsive Drug Delivery Nanoplatforms as Smart Carriers of Unsymmetrical Bisacridines for Targeted Cancer Therapy.

Selective therapy and controlled drug release at an intracellular level remain key challenges for effective cancer treatment. Here, we employed folic acid (FA) as a self-navigating molecule in nanoconjugates containing quantum dots (QDs) and β-cyclodextrin (β-CD) for the delivery of antitumor unsymmetrical bisacridine compound (C-2028) to lung and prostate cancers as well as normal cells. The bisacridine derivative can form the inclusion complex with β-cyclodextrin molecule, due to the presence of a planar fragment in its structure. The stability of such a complex is pH-dependent. The drug release profile at different pH values and the mechanism of C-2028 release from QDs-β-CD-FA nanoconjugates were investigated. Next, the intracellular fate of compounds and their influence on lysosomal content in the cells were also studied. Confocal Laser Scanning Microscopy studies proved that all investigated compounds were delivered to acidic organelles, the pH of which promoted an increased release of C-2028 from its nanoconjugates. Since the pH in normal cells is higher than in cancer cells, the release of C-2028 from its nanoconjugates is decreased in these cells. Additionally, we obtained the concentration profiles of C-2028 in the selected cells treated with unbound C-2028 or nanoconjugate by the HPLC analysis.

Anti-bacterial β-cyclodextrin derivatives inspired by the antimicrobial peptide polymyxin in order to better understand the role of single hydrophobic chain tail in selective anti-bacterial activity

Colistin-like poly-amino β-cyclodextrin molecules locally possessing a hydrophobic alkyl chain tail disrupted bacterial membranes without destroying animal cells, resulting in achievement of selective anti-bacterial activity.

A Co-based MOF as nanozyme with enhanced oxidase-like activity for highly sensitive and selective colorimetric differentiation of aminophenol isomers

Nanozyme with the merit of excellent and adjustable catalytic activity, outstanding stability and low cost is a promising alternative for natural enzymes widely applied in a variety of fields. In the present study, a new two-dimensional cobalt-based MOF nanocomposite designated as MVCM@β-CD was synthesized. Combined with the strategies of increasing the ratio of Co(Ⅲ)/Co(Ⅱ) and modifying with small molecule β-cyclodextrin (β-CD), MVCM@β-CD displayed remarkably enhanced oxidase-mimicking activity, which was attributed to synergistic effect from large surface area of two dimensional Co-MOF nanosheet, numerous exposed active sites, high-proportioned trivalence of cobalt and regulating action of β-cyclodextrin. The addition of aminophenol isomers inhibited the catalytic oxidation process, resulting in different color change of the solution and UV–Vis absorption behaviors, based on which a sensitive ratiometric colorimetry for m-aminophenol (m-Ap) and a simple colorimetric p-aminophenol (p-Ap) detection method were developed with the detection limit of 0.16 μM and 1.01 μM, respectively. This method realized the colorimetric differentiation of aminophenol isomers, which provided a simple, accurate and low-cost approach for visual discrimination without complicated instrument and procedure, especially appropriate for on-site detection.

Reduction-triggered polycyclodextrin supramolecular nanocage induces immunogenic cell death for improved chemotherapy

Polycyclodextrin-based supramolecular nanoplatform crosslinked by stimuli-responsive moiety shows great promise in cancer therapy owing to its superior bio-stability and feasible modification of architectures. Here, the endogenous glutathione (GSH)-responsive polycyclodextrin supramolecular nanocages (PDOP NCs) are constructed by covalent crosslinking of multiple β-cyclodextrin (β-CD) molecules. The polycyclodextrin provide sites for conjugation of chemotherapeutic doxorubicin (DOX). Meanwhile, the PDOP NCs are stabilized by multiple interactions including host-guest interaction between DOX and β-CD and hydrogen bonds between β-CD units. The supramolecular crosslinked structure endowed the nanocage with high stability and drug loading capacity. Tons of GSH-sensitive disulfide linkages in PDOP NCs were broken at tumor cells, promoting tumor-specific DOX release. Besides, the redox equilibrium in tumor microenvironment could be disturbed due to GSH depletion, which further sensitized the DOX effects and alleviated drug resistance, facilitating inducing immunogenic cell death effect for enhanced chemotherapy, thereby achieving efficient tumor suppression and prolonged survival. Thus, the versatile polycyclodextrin-based supramolecular nanocage provides a novel and efficient drug delivery strategy for cancer treatment.

Development of Drug Carriers with Biocompatibility Based On Human Serum Albumin and β-Cyclodextrin Molecules and Study of Anticancer Activity.

Herein, a novel molecule S4, which could form a uniform S4 spherical aggregate in water, was synthesized, and the S4 aggregate was used to load Dox to prepare the S4@Dox nanomedicine. The loading efficiency was 80.0 ± 4.5%. The pH response and slow release of Dox were the typical characteristics of the S4@Dox nanomedicine. In vitro experiments showed that cancer cells could successfully phagocytose S4 aggregates and the S4@Dox nanomedicine. The toxicity of S4 aggregates to MCF-7, HepG2, and H22 cells was low, and the S4@Dox nanomedicine had better antitumor activity and specific targeting, especially to the MCF-7 cells. The antitumor activity in vivo and in the tissue section showed that the S4@Dox nanomedicine could significantly reduce Dox toxicity, effectively induce the apoptosis of cancer cells, and effectively inhibit tumor growth, which showed that the nanomedicine had better antitumor activity.

Preparation and characterization of the dimethyl sulfide-β-cyclodextrin inclusion complex.

Dimethyl sulfide has been widely used in flavors and can also be used as a solvent and catalyst. However, dimethyl sulfide is volatile, and its lasting power is weak. Furthermore, dimethyl sulfide is insoluble in water and is unstable in some cases. This study concentrated on the encapsulation of dimethyl sulfide in β-cyclodextrin to form an inclusion complex and to improve the durability, water solubility, and stability of dimethyl sulfide. The product was successfully produced and characterized by scanning electron microscopy, diffraction of X-rays, and thermal analysis. The dimethyl sulfide loading capacity is 6.40±0.08%. Based on the thermal release characteristics of dimethyl sulfide, the kinetic and thermodynamic parameters were obtained. The apparent activation energy, pre-exponential factor, and reaction order of the dimethyl sulfide release reaction were obtained and the values were 95.0±0.1kJ/mol,1.03×1015 s-1 , and 1, respectively. The activation entropy change, activation enthalpy change, and activation Gibbs free energy change were 41.6 J/K, 95.0kJ/mol, and 81.3kJ/mol, respectively, during the process of dimethyl sulfide release at 56.7℃. To make it clear that the dimethyl sulfide molecule interacts with β-cyclodextrin molecule, molecular simulation was used to investigate the formation process of the dimethyl sulfide-β-cyclodextrin inclusion complex. The binding energy and the optimized structure were obtained. When the Z coordinate of the S atom in the dimethyl sulfide molecule is 1.1×10-10 m, the binding energy attained the minimum value, -51.3kJ/mol. These basic data are helpful for understanding the dimethyl sulfide-β-cyclodextrin inclusion complex formation mechanism and the interaction between dimethyl sulfide and β-cyclodextrin. PRACTICAL APPLICATION: By forming an inclusion complex with β-cyclodextrin, the stability, durability, and water solubility of dimethyl sulfide can be improved. Dimethyl sulfide-β-cyclodextrin inclusion complex can be widely used in the food, beverage, flavor, and fragrance industries. The kinetic and thermodynamic parameters, binding energy, and the results of molecular simulation are helpful to understand the dimethyl sulfide-β-cyclodextrin inclusion complex formation mechanism and the interaction between dimethyl sulfide and β-cyclodextrin.

Theoretical Investigation on Inclusion Complex of (s)-2-Isopropyl-1-(o-nitrophenyl) Sulfonyl) Aziridine with β-Cyclodextrin

The present work aims to study the theoretical chemistry applied to organic systems such as host / guest inclusion complexes. In literature different molecular modeling computation methods have been used to study the complexation of the host β-cyclodextrin molecule, with the guest (S) -2-Isopropyl-1- (o-nitrophenyl) sulfonyl) aziridine molecule, as semi-empirical PM3 and DFT (Density Functional Theory) calculations in gas and aqueous phases. The present paper focus on complexation, interaction and deformation energies determination, besides geometries, electronic structure, and chemical reactivity in order to describe the changes that AZ during encapsulation in two phases and two orientations. The results obtained with the Long-range corrected hybrid functional (WB97X-D / Base 6-31G (d))clearly indicate that the formed complex is energetically preferred in both phases, and the inclusion complex in the orientation A is more favorable than in the orientation B and shows good compatibility with the experimental results. NBO and NCI analysis were performed on the β - CD / AZ complex to understand the different interactions. The 1H nuclear magnetic resonance (NMR) of the complex was studied using the Gauge-Including Atomic Orbital (GIAO).

Amphiphilic cyclodextrins: Dimerization and diazepam binding explored by molecular dynamics simulations

Amphiphilic cyclodextrins spontaneously aggregate to form different supramolecular assemblies with potential applications in drug release. Herein, we employ extended molecular dynamics simulations in order to characterize the structure and dynamics in explicit solvent of several amphiphilic derivatives of the β-cyclodextrin (β-CD) molecule, with aliphatic chains ester-bound to the wide rim of the hydrophobic cavity. We also study the binding properties considering a typical guest (diazepam) and the dimerization of these macrocyclic systems, assessing the relative stability of the complexes by means of end-point free energy methods. Different lengths (C4, C10, and C14 atoms) are considered for the alkyl side chains included in the amphiphilic β-CD-Cn molecules. According to the simulations, the length of these Cn moieties determines the complexing and aggregation capabilities of the β-CD-Cn systems. Compared to the native β-CD, the alkyl side chains in the β-CD-Cn molecules destabilize the inclusion complexes with diazepam and hinder the access of guest molecules to the hydrophobic cavity. In turn, dimerization is favored in the largest amphiphilic derivatives associated to the hydrophobic interaction between the Cn fragments.

Thermodynamic Studies of Interactions between Sertraline Hydrochloride and Randomly Methylated β-Cyclodextrin Molecules Supported by Circular Dichroism Spectroscopy and Molecular Docking Results.

The interaction between sertraline hydrochloride (SRT) and randomly methylated β-cyclodextrin (RMβCD) molecules have been investigated at 298.15 K under atmospheric pressure. The method used—Isothermal Titration Calorimetry (ITC) enabled to determine values of the thermodynamic functions like the enthalpy (ΔH), the entropy (ΔS) and the Gibbs free energy (ΔG) of binding for the examined system. Moreover, the stoichiometry coefficient of binding (n) and binding/association constant (K) value have been calculated from the experimental results. The obtained outcome was compared with the data from the literature for other non-ionic βCD derivatives interacting with SRT and the enthalpy-entropy compensation were observed and interpreted. Furthermore, the connection of RMβCD with SRT was characterized by circular dichroism spectroscopy (CD) and complexes of βCD derivatives with SRT were characterized through the computational studies with the use of molecular docking (MD).

Self-Assembly and Photochemistry of a Pyrene-Methyl Viologen Supramolecular Fiber System.

This paper reports the self-assembly of a donor-acceptor system into nanoscopic structures and the photo processes taking place within these structures. The donor employed is pyrene linked to two β-cyclodextrin molecules (CD-PY-CD), and adamantane-linked methyl viologen attached to the three arms of mesitylene (Ms-(MV2+-AD)3) is the acceptor. CD-PY-CD and Ms-(MV2+-AD)3 when dissolved in water self-assembled into vesicles, which joined together to give long fibers. The self-assembly was studied using spectroscopic and microscopic techniques. Fluorescence of the pyrene chromophore was quenched within the self-assembled system due to efficient photoinduced electron transfer to methyl viologen. Photoinduced electron transfer within the assembly is confirmed through identification of product radical ions in flash photolysis experiments. Steady-state irradiation of the self-assembled system in an optical bench led to the formation of methyl viologen radical cation, which was stable for a few hours. Longevity of the radical cation was attributed to the fast reaction of pyrene radical cation with adjacent pyrene to give an unstable adduct, which slows down the back electron transfer process.

A supramolecular host-guest interaction-mediated injectable hydrogel system with enhanced stability and sustained protein release

Injectable hydrogels have been studied as drug delivery systems because of their minimal invasiveness and sustained drug release properties. Pluronic F127, consisting of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymers, exhibits thermo-responsive properties and hence is injectable due to its rapid sol-gel transition. Unmodified Pluronic F127-based hydrogels, however, have limited long-term stability and controllable release of drugs entrapped within them. In this study, host-guest interactions between adamantane-conjugated Pluronic F127 (F127-Ad) and polymerized β-cyclodextrin (CDP) were employed to develop a hydrogel-based protein delivery system. Single or multiple adamantane units were successfully introduced at the termini of Pluronic F127 with a 100% conversion yield, and the synthesized F127-Ad polymer produced a physically crosslinked micelle-packing structure when mixed with CDP. As the number of adamantanes at the terminal ends of Pluronic F127 increased, the critical gelation concentration of F127-Ad/CDP hydrogel decreased from 15 to 6% (w/v). The F127/CDP hydrogel was able to maintain its structure even with lower polymer content, and its injectability improved with a reduction of the hydrogel viscosity. The long-term stability of F127/CDP hydrogels was evaluated in vitro and in vivo, and it was demonstrated that the subcutaneously injected hydrogel did not disintegrate for up to 30 d. Throughout the drug release test using gelatin and insulin as model drugs, it was demonstrated that their release rates could be regulated via complexation between the protein drugs and the β-cyclodextrin molecules inside the hydrogel. In conclusion, the F127-Ad/CDP hydrogel is expected to be a versatile protein delivery system with controllable durability and drug release characteristics. Statement of significancePluronic F127 is one of the widely studied polymeric materials for thermo-sensitive injectable hydrogels due to its high biocompatibility and rapid sol-gel transition. Since the Pluronic F127-based hydrogel has some limitations in its long-term stability and mechanical property, it is inevitable to modify its structure for the application to drug delivery. In this study, mono- or multi- adamantane-conjugated Pluronic F127s were synthesized and mixed with β-cyclodextrin polymers to form hydrogels with host-guest interaction-mediated micelle-packing structures. The host-guest interaction introduced into the hydrogel system endowed it a sustained protein drug release behavior as well as high durability in vitro and in vivo. By increasing the number of adamantane molecules at the end of the Pluronic F127, both the stability and injectability of the hydrogel could be also modulated.

Β-Cyclodextrin Modified Reduced Graphene Oxide Based Chemiresistive Sensor for Detection of Lead (Pb(II)) in Water

Reduced graphene oxide or rGO, a much studied 2D material, is a chemical equivalent of graphene. rGO has been extensively studied in the field of wide variety of electrochemical, optical and spectroscopic sensors for accurate and selective detection of heavy metals in water. Lead (Pb (II)) is one of the most toxic heavy metals which causes numerous physiological and neurological hazards. It needs constant and efficient monitoring.Here, we report Chemiresistive sensing device for sensing Pb(II) ions. Chemiresistive sensing technique is derived from the very well-known FET based technique. Ease of fabrication and operation, no necessity of gate electrode and supporting electrolyte are the reasons for choosing Chemiresistive technique as the method for sensing Pb(II) in aqueous solution. Reduced graphene oxide was chosen to be the material for constructing the channel for charge carrier movement because of its excellent conductivity and stability in ambient conditions.In order to achieve this, graphene oxide (17mg/ml) was reduced in chemical route and was subsequently annealed thermally. We were able to make rGO films of dimension 20mmx20mm in this method. Electrodes were coated on the rGO film using an optimized amount of silver paste and they were further annealed at 120ºC. The roughness of the resulting film was around 50nm and the stacking of the rGO sheets was accounted for that. In our measurements, 5µl of Pb(NO3)2 solution of different concentrations were used. Milli Q water was used as the reference. The response was calculated as percentage change in resistivity in the presence of analyte under ambient conditions.The resistivity was found to increase in the presence of lead nitrate salt solution. For rGO, response towards 20 ppm and 50 ppm Pb(NO3)2 solution was around 1.47% and 6.23% respectively as shown in figure 1.a. The residual oxygen containing groups on rGO help in interacting with the lead ions. Doping or electrostatic gating effect is assumed to be the major contributing factor behind increase in resistivity of the sensing material. We incorporated selectivity into our Chemiresistive sensor by addition of β-cyclodextrin. The cavity size of β-cyclodextrin is such that it shows more affinity towards Pb(II) as compared to other smaller cations such as Cd(II). β-cyclodextrin modified rGO films showed up to 13.3% and 53.13% resistivity changes towards 20 ppm and 50 ppm Pb(NO3)2 solutions respectively, which was almost 10 times in comparison with only rGO as shown in figure 1.a. The calibration curve for rGO-β-cyclodextrin in the concentration range of 10 ppm to 50 ppm Pb(NO3)2 solutions is given in figure 1.b. Secondary deprotonation of the β-cyclodextrin molecule leads to the selective binding of the Pb(II) ions. Though the LOD (limit of detection) of our sensor lies in ppm range, this is the first Chemiresistive Pb(II) sensor ever reported. Further work is being carried out in this domain to lower the LOD and determine the uptake of Pb(II) by rGO-β-cyclodextrin. Figure 1

Development of sorbic acid microcapsules and application in starch‐poly (butylene adipate co‐terephthalate) films

Sorbic acid (SA) microcapsules were prepared by molecular inclusion in β-cyclodextrin, aiming to improve the physical properties of the acid, in order to facilitate its applicability in the formulation of PBAT films, obtained by extrusion. FTIR, DSC, and NMR-H1 methods verified the interaction between SA and β-cyclodextrin molecules and the formation of the inclusion complex. A thermal stability test showed that the microencapsulated SA can withstand film production temperatures. Starch films were elaborated by extrusion, using SA in free form (F1) and microencapsulated form (F2), and submitted to water vapor permeability, with no significant difference between formulations. As to mechanical properties, the F2 formulation presented significantly lower tensile strength and modulus of elasticity when compared to F1. The films were submitted to SA release test and showed the highest amount of SA when microencapsulated, with controlled release of the compound, evidencing the efficiency of SA microencapsulation for application in extruded films. Novelty impact statement Sorbic acid (SA) microcapsules were produced by the molecular inclusion method in β-CD and incorporated into starch-poly (butylene adipate co-terephthalate) (PBAT) films obtained by extrusion. The films produced with inclusion complex presented alterations in mechanical properties and color, due to the addition of β-CD in the formulation. The microencapsulation protected SA during film preparation, reducing its sublimation at high temperatures, and provided a controlled release of SA.

Generation of Long-Lived Photoinduced Charge Separation in a Supramolecular Toroidal Assembly.

Efficiencies of artificial photosynthetic and photocatalytic systems depend on their ability to generate long-lived charge-separated (CS) states in photoinduced electron transfer (PET) reactions. PET, in most cases, is followed by an ultrafast back electron transfer, which severely reduces lifetime and quantum yield of CS states. Generation of a long-lived CS state is an important goal in the study of PET reactions. Herein, we report that this goal is achieved using a hierarchically self-assembled anthracene-methyl viologen donor-acceptor system. Anthracene linked to two β-cyclodextrin molecules (CD-AN-CD) and methyl viologen linked to two adamantane units (AD-MV2+-AD) form an inclusion complex in water, which further self-assembled into well-defined toroidal nanostructures. The fluorescence of anthracene is highly quenched in the self-assembled system because of PET from anthracene to methyl viologen. Irradiation of the aqueous toroidal solution led to formation of a long-lived CS state. Rational mechanisms for the formation of the toroidal nanostructures and long-lived photoinduced charge separation are presented in the paper.

Synthesis of photoluminescent glycodendrimer with terminal β-cyclodextrin molecules as a biocompatible pH-sensitive carrier for doxorubicin delivery

In the present research, we prepared new glycodendrimer containing β-cyclodextrin (β-CD) in three steps. At first, graphene quantum dots (GQDs) synthesized through pyrolysis of the citric acid (CA). Then the polyamidoamine (PAMAM) dendrimer was grown from the surface of the modified GQDs (GQDs-PAMAM). Finally, the prepared GQDs-PAMAM was functionalized with β-CD to obtain the glycodendrimer (GQDs-PAMAM-β-CD). The synthesized glycodendrimer characterized using several techniques. The phenol-sulfuric acid test obtained the amount of the β-CD about 30.37 %. 61.2 % of doxorubicin (DOX) was loaded in the prepared glycodendrimer. DOX@GQDs-PAMAM-β-CD displayed the pH-sensitive drug release profile, which fitted the Higuchi kinetic model. The biological test outcomes showed that the GQDs-PAMAM-β-CD is a safe carrier with good capability in penetration to the cancer cells. Moreover, DOX@GQDs-PAMAM-β-CD exhibited more efficiency in the killing of the cancer cells compared to neat DOX. Obtained results suggested that prepared glycodendrimer could be a potential nanosystem for breast cancer treatment.