Water-soluble Β-cyclodextrin Polymer Research Articles

Preparation and evaluation of a functional effervescent powder based on inclusion complexes of orange oil and β-cyclodextrin derivatives

Flavoured functional effervescent powders are becoming increasingly popular by consumers due to their health benefits and easy dissolution. In present study, orange flavoured effervescent powders having functional properties were prepared. Orange oil (O) was blended with different essential oils (EOs) that have high antioxidant activity. The orange oil and the O-EOs blends were subjected to odour sensory evaluation, gas chromatography-mass spectrometry (GC-MS) analysis and evaluation of radical scavenging activity. Combinations of two water soluble β-cyclodextrin polymers, 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) and epichlorohydrin-β-cyclodextrin (EPI-β-CD), were prepared at different molar ratios (3:1 and 1:3, F1 and F2, respectively). The O-EOs blends that showed the highest antioxidant activities and best odour qualities were encapsulated with F1 and F2, separately. The orange flavoured inclusion complexes were prepared by freeze drying method. The particle sizes of the inclusion complex powders were in the nanoscale. Characterization of the inclusion complexes nanoparticles was performed by scanning electron microscopy (SEM), and fourier transform infrared microscopy (FT-IR). The results confirmed the successful formation of the inclusion complexes. However, inclusion complex of O-EOs (300 mg) blend with F1 (OF1cIC) showed the smallest particle size (113.90±15.90 nm), the more negative zeta potential (−27.10±1.27 mV), the highest encapsulation efficiency (95.51%) and best odour quality. Therefore, it was mixed with an effervescent powder having high acceptable characteristics. The orange flavoured effervescent powder showed superior flowability.

PAAS-β-CDp-PAA as a high-performance easily prepared and water-soluble composite binder for high-capacity silicon anodes in lithium-ion batteries

The hyperbranched hydroxyl-rich water-soluble β-cyclodextrin polymer (β-CDp) is synthesized by the reaction between β-cyclodextrin and 1, 4-butanediol diglycidyl ether with a facile and environmentally friendly method, which is systematically confirmed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric (TG). A water-soluble PAAS-β-CDp-PAA binder is prepared by the esterification reaction between partially neutralized sodium polyacrylate (PAAS), β-CDp, and polyacrylic acid (PAA). Moreover, the optimized PAAS6-β-CDp1-PAA3 binder, with a three-dimensional (3D) cross-linked network structure constructed by covalent bonds, hydrogen bonds, and electrostatic interactions, displays a stronger adhesion between the active material and the current collector, effectively promotes the diffusion of Li+, and maintains the structural integrity of the electrode during charge-discharge cycling. Thus Si/PAAS6-β-CDp1-PAA3 electrode exhibits a higher initial discharge specific capacity of 3869 mAh g−1 with a columbic efficiency of 89.79% at 200 mA g−1, and a discharge specific capacity of 2513 mAh g−1 with a capacity retention rate of 71.10% is achieved after 100 cycles.

Enhancing in vitro cytotoxicity of doxorubicin against MCF-7 breast cancer cells in the presence of water-soluble β-cyclodextrin polymer as a nanocarrier agent

This study was aimed to evaluate the impact of water-soluble β-cyclodextrin polymer (β-CDP), as a nanocarrier, on the therapeutic efficacy of the commercial doxorubicin (DOX). The β-CDP was synthesized by cross-linking of β-CD using epichlorohydrin. The chemical structure of the cross-linked β-CDP was verified by NMR and thermogravimetric analysis. The solubility of β-CDP in water was around 880 g in 1000 mL. Next, the DOX/β-CDP was formulated by the addition of the polymer into the various concentrations of DOX in a weight ratio of 1:10 and 1:20 (DOX: β-CDP). The formation of the inclusion complex of DOX with β-CDP was studied by UV–Vis spectroscopy. The UV–Vis spectra of DOX/β-CDP formulations show the appearance of the absorption peak at 480 nm and a significant decrease in the absorbance intensity of DOX signal compared to DOX solution. This verified the formation of the DOX/β-CDP complex and also the presence of free DOX in the DOX/β-CDP formulation. The hydrodynamic size of DOX/β-CDP formulation was obtained in the range of nanometer, and the complexion of DOX by β-CDP leads to a negative shift in the zeta potential. In vitro release profile shows a burst release followed by sustained release of DOX from DOX/β-CDP formulation. This is due to the presence of both free and encapsulated DOX. The cytotoxic effect of DOX solution and DOX/β-CDP formulation was evaluated by MTT assay against breast cancer (MCF-7) cell line. The anticancer activity of the DOX/β-CDP was higher than the DOX.

Synthesis and characterization of water-soluble β-cyclodextrin polymers via thiol-maleimide ‘click’ chemistry

Water-soluble β-cyclodextrin polymers (β-CDPs) employing thiolated β-cyclodextrin (β-CD-(SH)7) and maleimide-functionalized hydroxypropyl-β-cyclodextrin (HPCD-AMI) were successfully synthesized in aqueous solution via thiol-maleimide ‘click’ chemistry. The intermediate and final synthesized β-CDPs were characterized by Fourier transform infrared spectroscopy (FT-IR), 1H nuclear magnetic resonance (1H NMR), Matrix-assisted laser desorption ionization-time of flight mass spectroscopy (MALDI-TOF), size exclusion chromatography (SEC), X-ray powder diffractometer (XRD), and thermalgravimetric analysis (TGA). It was found that the Mw of β-CDPs increased with both feed ratio of HPCD-AMI/β-CD-(SH)7 and reaction temperature. Moreover, the 1H NMR indicated that β-CDPs prepared at elevated temperature have higher degree of thiol-maleimide reaction compared to that prepared at room temperature, thereby leading to more compact star-like branched structure. Phase solubility study showed that the affinity of curcumin with β-CDPs was significantly higher than that with the native β-CD and HPβ-CD. The increase of Mw resulted in an increased or decreased complex-forming capacity, depending on the microstructure of β-CDPs. Besides, the release behavior study confirmed that β-CDPs exhibited excellent sustained-release ability for curcumin. These results suggest that the prepared β-CDPs can be a promising candidate in drug delivery and pharmaceutical application.

Water-Soluble β-cyclodextrin Polymers as Drug Carriers to Improve Solubility, Thermal Stability and Controlled Release of Nifedipine

Two types of water-soluble β-cyclodextrin polymers (β-CD-ECH polymer) were prepared by polymerization of β-cyclodextrin (β-CD) using epichlorohydrin (ECH) as cross-linking agent under basic conditions. These polymers contain 34% and 49% β-CD in structure and their solubilities in water are 563 and 875 g/1000 mL, respectively. The obtained polymers were characterized by DSC, DDSC, TGA, DTG and FT-IR spectroscopy techniques. The drug loading capacities of β-CD-ECH polymer matrices have been evaluated for nifedipine (NIF), which is a poorly water-soluble and highly photosensitive drug. Phase solubility studies showed complexation constants of 145.55 and 198.06 M–1. In addition, supplementary data from solubility tests demonstrated that solubility of NIF in water was greatly increased through complexation with β-CD-ECH polymer. So, thermal stability of the polymer-encapsulated NIF was considerably improved owing to inclusion complexation with β-CD-ECH polymer. The results of in vitro release studies confirmed that NIF release from β-CD-ECH polymer was pH-dependent. Mathematical modeling using Higuchi and Korsmeyer – Peppas equations suggested Fickian diffusion as the mechanism of NIF release.

Synthesis and characterization of a hyper-branched water-soluble β-cyclodextrin polymer

A new hyper-branched water-soluble polymer was synthesized by reacting β-cyclodextrin with pyromellitic dianhydride beyond the critical conditions that allow the phenomenon of gelation to occur. The molar ratio between the monomers is a crucial parameter that rules the gelation process. Nevertheless, the concentration of monomers in the solvent phase plays a key role as well. Hyper-branched β-cyclodextrin-based polymers were obtained performing the syntheses with excess of solvent and cross-linking agent, and the conditions for critical dilution were determined experimentally. A hyper-branched polymer with very high water solubility was obtained and fully characterized both as for its chemical structure and for its capability to encapsulate substances. Fluorescein was used as probe molecule to test the complexation properties of the new material.

Research on association between multi-sticker amphiphilic polymer and water-soluble β-cyclodextrin polymer

The host cyclodextrin polymer-P(AM/A-β-CD/NaA) is prepared by redox free-radical copolymerization. Additionally, the multi-sticker amphiphilic polymer-P(AM/BHAM/NaA) as a guest polymer is synthesized using micellar polymerization. The copolymer structures are characterized by 1H NMR. Subsequently, all the polymers and inclusion complexes are evaluated in terms of apparent viscosity, optical absorption spectra and rheological property. The results indicate that the inclusion association between the cyclodextrin group (CD) and multi-sticker hydrophobic monomer (BHAM) is in accordance with ternary interaction (CD/BHAM = 2:1). Because of the inclusion association between the host and guest polymers, the solution of inclusion complex has much higher viscoelasticity even under the low amphiphilic polymer concentration. When the molar ratio of CD to BHAM is 1:1, the critical aggregation concentration (CAC) of the inclusion complex solution still remains. Furthermore, above the CAC, two types of associations, inclusion association and inter-molecular hydrophobic association, can occur in the complex solution and these interactions were also verified by fluorescence spectroscopy and atomic force microscopy (AFM). In this paper, the inclusion rule of cyclodextrin polymer with the multi-sticker amphiphilic polymer is discussed, and the rule of the enhanced solution viscosity is further explored.

β-Cyclodextrin polymer functionalized reduced-graphene oxide: Application for electrochemical determination imidacloprid

Reduced-graphene oxide (rGO) modified with water-soluble β-cyclodextrin polymer (β-CDP) were successfully prepared by using a simple wet chemical strategy. The obtained β-CDP/rGO nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), static contact angle measurement, thermogravimetric analysis (TGA), scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS), which confirmed that β-CDP molecules had been effectively loaded onto the surface of rGO. β-CDP/rGO nanocomposites displayed the excellent water-dispersity and stability. More significantly, cyclic voltammetry and differential pulse voltammetry measurement showed that the β-CDP/rGO could exhibit high supramolecular recognition and enrichment capability, and consequently display excellent electrochemical response toward a pesticide-imidacloprid (IDP). As compared with various modified electrodes, β-CDP/rGO modified glassy carbon electrode exhibited an excellent electrochemical performance for IDP. Based on the cyclic voltammograms (CV) of different concentration of IDP at pH 6.8, the detection line range of IDP is 1×10−6 to 1.5×10−4molL−1 IDP and the detection limit is 1×10−7molL−1. Differential pulse voltammetry (DPV) measurement at β-CDP/rGO/GCE modified electrode revealed that the reduction peak current increased linearly with the concentration of IDP in linear range of 5×10−8 to 1.5×10−5molL−1 and 2×10−5 to 1.5×10−4molL−1 with detection limit of 2×10−8molL−1 at a signal-to-noise ratio of 3.

Synthesis and characterization of poly(ethylene glycol) based β-cyclodextrin polymers

A series of novel water soluble β-cyclodextrin (βCD) polymers has been synthesized from functionalized poly(ethylene glycol) (PEG). The chemical composition of the polymers has been characterized by 1H NMR and the βCD content is found to be between 48 and 33% (w/w). The molecular weight has been determined by Size Exclusion Chromatography (SEC) and depends on the ratio between βCD and PEG, varying from 2.1 × 104 to 8.6 × 104 g mol−1. The physico chemical properties have been characterized by differential scanning calorimetry (DSC), viscometry and isothermal titration calorimetry (ITC). ITC shows that the polymers have association constants comparable to βCD with different guest molecules, indicating a good accessibility of the CDs.

No delayed temporal response to sample concentration changes during enhanced microdialysis sampling using cyclodextrins and antibody-immobilized microspheres

The temporal response to concentration changes external to a microdialysis probe containing trapping agents in the perfusion fluid was studied. Native beta-cyclodextrin and a water-soluble beta-cyclodextrin polymer were used as trapping agents in the microdialysis perfusion fluid to study the temporal concentration response to carbamazepine, a hydrophobic analyte. The temporal response of microdialysis probes containing antibody-immobilized microspheres against five different cytokines (tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-4, and IL-5) to concentration changes outside of the probe was also determined. In both cases, no delayed temporal response of enhanced microdialysis was observed for either carbamazepine or the cytokines as compared to standard microdialysis sampling procedures.

Binding of dibenzofuran and its derivatives to water-soluble β-cyclodextrin polymers

The binding capacity of β-cyclodextrin polymers (β-CDP), cross-linked with epichlorohydrin, has been compared with that of unimeric β-cyclodextrin for the inclusion of dibenzofuran (DBF) and two of its derivatives: 2-hydroxydibenzofuran (DBFOH) and dibenzofuran 2-carboxylate (DBFC). Gel permeation chromatography, 1H and 13C NMR, and dynamic light scattering, together with membrane ultrafiltration, were used to characterize and fractionate the polymeric samples. Their interactions with the dibenzofuran derivatives have been analyzed by absorption and fluorescence spectroscopies. Fluorescence anisotropy titrations were used to obtain the apparent binding constants. The affinity of the neutral dibenzofurans for the polymers is significantly higher than those of the unimeric β-CD, irrespective of the molecular weight or the microstructure of the polymer, whereas the charge in the anionic dibenzofuran derivative hinders the formation of the complex. The most hydrophobic DBF shows a higher affinity for the polymer with a higher content in β-CD, whereas the opposite behavior is displayed for DBFOH. The results are explained in terms of the synergic effect produced by the glyceryl cross-linking bridges, the relative hydrophobicity of the guest–host system and the density of the polymer network.

Novel temperature-sensitive, ?-cyclodextrin-incorporated poly(N-isopropylacrylamide) hydrogels for slow release of drug

Novel temperature-sensitive poly(N-isopropylacrylamide) hydrogels containing water-soluble β-cyclodextrin polymer were prepared by forming semi-interpenetrating polymeric networks. Compared to the conventional poly(N-isopropylacrylamide) gel, the β-cyclodextrin-incorporated hydrogels showed the same lower critical solution temperature due to the independence of the β-cyclodextrin polymer in the networks. The release time of ibuprofen from the novel gel was significantly prolonged, which was presumably attributed to the formation of the inclusion complexes between the cyclodextrin groups and the drug molecules.

Association of poly- N-[tris(hydroxymethyl)methyl] acrylamide with a water soluble β-cyclodextrin polymer

An acrylic polymer with pendent adamantyl groups was synthesized and its properties in an aqueous solution with a β-cyclodextrin (βCD) epichlorhydrin polymer examined. Viscosity properties of precursor and modified polymers show differences at low concentrations, but not at higher concentration probably due to very important hydrogen bonds which prevent the formation of intermolecular hydrophobic bonds. The association of both complementary polymers through the inclusion of adamantyl groups is evidenced by phases separation occurrence. Phase diagrams were established at two different concentrations of polymers. We have shown a maximal association of both polymers at these two concentrations, for the same ratio βCD moles/adamantyl groups: 2.4. Salt addition favors this association and displaces the two phases zone to smaller concentrations of modified polymer. Further, 4-nitrophenol can be extracted by the concentrated phase resulting from mixture of solutions of guest and host polymers, pointing out the availability of the associated phase to trap organic molecules.

Interaction of Pesticides with a β-Cyclodextrin Derivative Studied by Reversed-phase Thin-layer Chromatography and Principal Component Analysis

The interaction of 18 pesticides with a water-soluble β-cyclodextrin polymer (BCDP) was studied by reversed-phase thin-layer chromatography and principal component analysis (PCA) was employed for the elucidation of the relationship between the relative strength of interaction and the calculated surface parameters of the guest molecules. Except for penconazole the lipophilicity of the pesticides decrease in the presence of BCDP. PCA indicated that apolar surface parameters are highly positively correlated with the strength of interaction. The data indicate that the agrochemical characteristics (adsorption, leakage, decomposition, etc) of complexed pesticide molecules can be different from those of uncomplexed onesresulting in modified efficacy.

BINDING CHARACTERISTICS OF A WATER-SOLUBLE β-CYCLODEXTRIN POLYMER

The interaction of 18 commercial pesticides with a water-soluble β-cyclodextrin polymer (BCDP) was determined by charge-transfer reversed phase thin layer chromatography and the relative strength of interaction was calculated. The relationship between the calculated surface parameters of pesticides and their capacity to interact with BCDP was elucidated by stepwise regression analysis. BCDP decreased the lipophilicity of the majority of pesticides probably by the formation of inclusion complexes. Significant quadratic relationships were found between the relative strength of interaction and the polar surface area and polar surface energy of pesticides emphasizing the impact of surface characteristics on the relative strength of interaction. The result suggests that the agrochemical properties (adsorption, uptake, half-life, etc.) of pesticide - BCDP complex may be different from those of uncomplexed compounds resulting in modified effectivity.

Association of hydrophobically modified poly ( N, N-dimethylacrylamide hydroxyethylmethacrylate) with water soluble β-cyclodextrin polymers

Hydrophobically associating polymers have been obtained by chemical modification of poly ( N, N-dimethyl acrylamide hydroxyethylmethacrylate) consisting in the introduction of adamantyl groups (Ad). Viscosity studies of dilute solutions of modified polymers show lower reduced viscosities than precursor solutions attributed to intramolecular hydrophobic associations. At higher concentrations intermolecular associations take place. In all cases, the viscosities are of limited value. Hydrophobic microdomains were evidenced by static fluorescence measurements in the presence of pyrene and critical aggregation concentrations determined. A study of fluorescence versus temperature has shown a modification of hydrophobic properties above 40°C corresponding to a coiling of the molecules, masking the hydrophobic groups. When these modified polymers are added to solutions of β-cyclodextrin epichlorhydrin polymer (βCD/EP), associations take place between the two polymers due to inclusion of adamantyl groups in cyclodextrin cavities. High viscosity enhancements are observed which are maximum for a precise composition of both polymers. This composition corresponds to the stoechiometry 1 adamantyl group for 1 CD cavity and varies with molecular weight and hydrophobe content of the modified polymer. Associative phase diagrams were stated which confirm the strong association of both polymers via inclusion of adamantyl groups in the β-cyclodextrin cavities.

Interaction of some steroid drugs with β-cyclodextrin polymer

The interaction of 15 steroidal drugs with a water-soluble β-cyclodextrin polymer was studied by reversed-phase thin-layer chromatography in the absence and in the presence of 0.1 M sodium chloride. The relative strength of interaction was calculated and the relationship between the hydrophobicity parameters of the drugs and the strength of the drug–β-cyclodextrin polymer was elucidated by principal component analysis. Drugs readily formed inclusion complexes with the cyclodextrin derivatives; the strength of the interaction was higher in the presence of sodium chloride. It was assumed that the formation of inclusion complexes may influence the behaviour of the drugs resulting in modified biological efficacy.

AQUEOUS TWO PHASE SYSTEMS FROM CYCLODEXTRIN POLYMERS AND HYDROPHOBICALLY MODIFIED ACRYLIC POLYMERS

ABSTRACT In this study, a copolymer of N,N-dimethylacrylamide and hydroxyethyl-methacrylate was synthesized and hydrophobically modified with about 2 mole % of adamantyl groups. The mixing of this modified copolymer with water-soluble β-cyclodextrin polymers reveals thickening properties. Inclusion complexes formation between adamantyl groups and β-cyclodextrin cavities are responsible of intermolecular associations. Above a given total polymer concentration a phase separation occurs, giving a gel phase topped by a liquid phase. We have stated the phase diagram by analysis of the two phases in equilibrium. It has been observed that the two polymers are present in both phases and that the gel phase is more concentrated than the other one. This phase behavior is an original complex coacervation phenomenom which is due to the specific attractive interactions of the two different macromolecules: inclusion complexes formed between the two neutral polymers.

Preparation and characterization of water soluble high molecular weight β-cyclodextrin-epichlorohydrin polymers

Water soluble β-cyclodextrin polymers were prepared from β-cyclodextrin crosslinked with epichlorohydrin under basic conditions. The influence of preparation conditions on the molecular weight distribution has been investigated. The knowledge of this relationship allows for the choice of reaction parameters according to the desired weight distribution of the β-cyclodextrin polymer. A procedure was developed for the preparation of high molecular weight water soluble polymer ( Mw higher than 10 4).

Reversed-phase thin-layer chromatography of various pesticides in the presence of water-soluble beta-cyclodextrin polymer

The modification of the hydrophobicity of 28 commercial pesticides with a water-soluble β-cyclodextrin polymer (SCDP) in the presence of aqueous NaCl has been studied by reversed-phase thin-layer chromatography. The pesticides formed inclusion complexes with SCDP and these complexes are less lipophilic than the parent pesticides. The sodium chloride exerted a typical saltingout effect, the retention of each pesticide increased with increasing concentration of the salt in the eluent. This effect can be tentatively explained by the suppression of the dissociation of the polar groups in the solute molecules resulting in increased apparent lipophilicity. The correlation between lipophilicity and salting-out effect was found to be significant, that is the salting-out effect increases with increasing polarity (lower lipophilicity) of the pesticides, whereas the lipophilicity has negligible influence on the inclusion-forming capacity of non-homologous series of pesticides.