WorldWideScience

Sample records for cyclodextrins

  1. Cyclodextrin chemistry

    International Nuclear Information System (INIS)

    Khan, M.Z.; Chuaqui, C.A.

    1990-05-01

    The chemistry of cyclodextrins was studied. This study included synthesising some cyclodextrin derivatives, preparing selected inclusion complexes with cyclodextrin and investigating the effects of gamma irradiation on cyclodextrins and certain linear oligosaccharides. This report presents a brief review of the structure and properties of cyclodextrins, the synthesis of cyclodextrin derivatives, their complexation and applications. This is followed by a description of the synthesis of some cyclodextrin derivatives and the preparation of inclusion complexes of cyclodextrin with some organic compounds. Finally, the effects of gamma irradiation on cyclodextrins, some of their derivatives and certain structurally related carbohydrates are discussed. The gamma irradiation studies were carried out for two reasons: to study the effects of gamma irradiation on cyclodextrins and their derivatives; and to investigate selectivity during the gamma irradiation of cyclodextrin derivatives

  2. Cyclodextrins and their pharmaceutical applications.

    Science.gov (United States)

    Loftsson, Thorsteinn; Duchêne, Dominique

    2007-02-01

    Cyclodextrins were first described by Villiers in 1891. Schardinger laid the foundation of the cyclodextrin chemistry in 1903-1911 and identified both alpha- and beta-cyclodextrin. In the 1930s, Freudenberg identified gamma-cyclodextrin and suggested that larger cyclodextrins could exist. Freudenberg and co-workers showed that cyclodextrins were cyclic oligosaccharides formed by glucose units and somewhat later Cramer and co-workers described their ability to form inclusion complexes. By the early 1950s the basic physicochemical characteristics of cyclodextrins had been discovered, including their ability to solubilize and stabilize drugs. The first cyclodextrin-related patent was issued in 1953 to Freudenberg, Cramer and Plieninger. However, pure cyclodextrins that were suitable for pharmaceutical applications did not come available until about 25 years later and at the same time the first cyclodextrin-containing pharmaceutical product was marketed in Japan. Later cyclodextrin-containing products appeared on the European market and in 1997 also in the US. New cyclodextrin-based technologies are constantly being developed and, thus, 100 years after their discovery cyclodextrins are still regarded as novel excipients of unexplored potential.

  3. Amphiphilic cyclodextrin nanoparticles.

    Science.gov (United States)

    Varan, Gamze; Varan, Cem; Erdoğar, Nazlı; Hıncal, A Atilla; Bilensoy, Erem

    2017-10-15

    Cyclodextrins are cyclic oligosaccharides obtained by enzymatic digestion of starch. The α-, β- and γ- cyclodextrins contain respectively 6, 7 and 8 glucopyranose units, with primary and secondary hydroxyl groups located on the narrow and wider rims of a truncated cone shape structure. Such structure is that of a hydrophobic inner cavity with a hydrophilic outer surface allowing to interact with a wide range of molecules like ions, protein and oligonucleotides to form inclusion complexes. Many cyclodextrin applications in the pharmaceutical area have been widely described in the literature due to their low toxicity and low immunogenicity. The most important is to increase the solubility of hydrophobic drugs in water. Chemically modified cyclodextrin derivatives have been synthesized to enhance their properties and more specifically their pharmacological activity. Among these, amphiphilic derivatives were designed to build organized molecular structures, through selfassembling systems or by incorporation in lipid membranes, expected to improve the vectorization in the organism of the drug-containing cyclodextrin cavities. These derivatives can form a variety of supramolecular structures such as micelles, vesicles and nanoparticles. The purpose of this review is to summarize applications of amphiphilic cyclodextrins in different areas of drug delivery, particularly in protein and peptide drug delivery and gene delivery. The article highlights important amphiphilic cyclodextrin applications in the design of novel delivery systems like nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Cyclodextrins in drug carrier systems.

    Science.gov (United States)

    Uekama, K; Otagiri, M

    1987-01-01

    One of the important characteristics of cyclodextrins is the formation of an inclusion complex with a variety of drug molecules in solution and in the solid state. As a consequence of intensive basic research, exhaustive toxic studies, and realization of industrial production during the past decade, there seem to be no more barriers for the practical application of natural cyclodextrins in the biomedical field. Recently, a number of cyclodextrin derivatives and cyclodextrin polymers have been prepared to obtain better inclusion abilities than parent cyclodextrins. The natural cyclodextrins and their synthetic derivatives have been successfully utilized to improve various drug properties, such as solubility, dissolution and release rates, stability, or bioavailability. In addition, the enhancement of drug activity, selective transfer, or the reduction of side effects has been achieved by means of inclusion complexation. The drug-cyclodextrin complex is generally formed outside of the body and, after administration, it dissociates, releasing the drug into the organism in a fast and nearly uniform manner. In the biomedical application of cyclodextrins, therefore, particular attention should be directed to the magnitude of the stability constant of the inclusion complex. In the case of parenteral application, a rather limited amount of work has been done because the cyclodextrins in the drug carrier systems have to be more effectively designed to compete with various biological components in the circulatory system. However, the works published thus far apparently indicate that the inclusion phenomena of cyclodextrin analogs may allow the rational design of drug formulation and that the combination of molecular encapsulation with other carrier systems will become a very effective and valuable method for the development of a new drug delivery system in the near future.

  5. Complexation and sensing behavior of dansyl-appended cyclodextrins and cyclodextrin dimers with bile salts

    NARCIS (Netherlands)

    Jong, de M.R.; Berthault, P.; Hoek, van A.; Visser, A.J.W.G.; Huskens, J.; Reinhoudt, D.N.

    2002-01-01

    The dansyl-modified cyclodextrin derivatives 2 and 3 form complexes with the steroidal bile salts. The selectivity of the monomeric derivative 3 is similar to that of native g-cyclodextrin. All binding constants with 3 are lowered compared to g-cyclodextrin because of the competition for the cavity

  6. Complexation and sensing behavior of dansyl-appended cyclodextrins and cyclodextrin dimers with bile salts

    NARCIS (Netherlands)

    de Jong, M.R.; Berthault, Patrick; van Hoek, Arie; Visser, Antonie J.W.G.; Huskens, Jurriaan; Reinhoudt, David

    2002-01-01

    The dansyl-modified cyclodextrin derivatives 2 and 3 form complexes with the steroidal bile salts. The selectivity of the monomeric derivative 3 is similar to that of native β-cyclodextrin. All binding constants with 3 are lowered compared to β-cyclodextrin because of the competition for the cavity

  7. Cyclodextrin Aldehydes are Oxidase Mimics

    DEFF Research Database (Denmark)

    Fenger, Thomas Hauch; Bjerre, Jeannette; Bols, Mikael

    2009-01-01

    Cyclodextrins containing 6-aldehyde groups were found to catalyse oxidation of aminophenols in the presence of hydrogen peroxide. The catalysis followed Michaelis-Menten kinetics and is related to the catalysis previously observed with cyclodextrin ketones. A range of different cyclodextrin aldeh...

  8. Cyclodextrins as excipients in tablet formulations.

    Science.gov (United States)

    Conceição, Jaime; Adeoye, Oluwatomide; Cabral-Marques, Helena Maria; Lobo, José Manuel Sousa

    2018-04-22

    This paper aims to provide a critical review of cyclodextrins as excipients in tablet formulations, highlighting: (i) the principal pharmaceutical applications of cyclodextrins; (ii) the most relevant technological aspects in pharmaceutical formulation development; and (iii) the actual regulatory status of cyclodextrins. Moreover, several illustrative examples are presented. Cyclodextrins can be used as complexing excipients in tablet formulations for low-dose drugs. By contrast, for medium-dose drugs and/or when the complexation efficiency is low, the methods to enhance the complexation efficiency play a key part in reducing the cyclodextrin quantity. In addition, these compounds are used as fillers, disintegrants, binders and multifunctional direct compression excipients of the tablets. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Selectively Modified Cyclodextrins as Artificial Glycosidases

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Bols, Mikael

    2008-01-01

    I proceedingen beskrives forfatterens og gruppens arbejde med at skabe kunstige glycosidaser baseret på beta-cyclodextrin. Vha. selektiv modificering af 1-2 alkohol-grupper på den primære rand af beta-cyclodextrin, er syntetiseret en række kunstige glycosidaser. Disse cyclodextrin-baserede glycos...

  10. A novel preparation of methyl-β-cyclodextrin from dimethyl carbonate and β-cyclodextrin

    DEFF Research Database (Denmark)

    Gan, Yongjiang; Zhang, Yimin; Xiao, Chuanhao

    2011-01-01

    A novel green synthesis process about methyl-β-cyclodextrin has been investigated through the reaction between β-cyclodextrin and dimethyl carbonate by anhydrous potassium carbonate as catalyst in DMF. The influence of experimental factors including the molar ratio of dimethyl carbonate to β-cycl...

  11. Complexation thermodynamics of modified cyclodextrins

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Holm, Rene

    2014-01-01

    Inclusion complexes between two bile salts and a range of differently methylated β-cyclodextrins were studied in an attempt to rationalize the complexation thermodynamics of modified cyclodextrins. Calorimetric titrations at a range of temperatures provided precise values of the enthalpies (ΔH......°), entropies (ΔS°), and heat capacities (ΔCp) of complexation, while molecular dynamics simulations assisted the interpretation of the obtained thermodynamic parameters. As previously observed for several types of modified cyclodextrins, the substituents at the rims of the cyclodextrin induced large changes......° and then a strong decrease when the degree of substitution exceeded some threshold. Exactly the same trend was observed for ΔCp. The dehydration of nonpolar surface, as quantified by the simulations, can to a large extent explain the variation in the thermodynamic parameters. The methyl substituents form additional...

  12. The evolution of cyclodextrin glucanotransferase product specificity

    NARCIS (Netherlands)

    Kelly, Ronan M.; Dijkhuizen, Lubbert; Leemhuis, Hans

    Cyclodextrin glucanotransferases (CGTases) have attracted major interest from industry due to their unique capacity of forming large quantities of cyclic alpha-(1,4)-linked oligosaccharides (cyclodextrins) from starch. CGTases produce a mixture of cyclodextrins from starch consisting of 6 (alpha), 7

  13. Efficacy and Safety Profile of Diclofenac/Cyclodextrin and Progesterone/Cyclodextrin Formulations: A Review of the Literature Data.

    Science.gov (United States)

    Scavone, Cristina; Bonagura, Angela Colomba; Fiorentino, Sonia; Cimmaruta, Daniela; Cenami, Rosina; Torella, Marco; Fossati, Tiziano; Rossi, Francesco

    2016-06-01

    According to health technology assessment, patients deserve the best medicine. The development of drugs associated with solubility enhancers, such as cyclodextrins, represents a measure taken in order to improve the management of patients. Different drugs, such as estradiol, testosterone, dexamethasone, opioids, non-steroidal anti-inflammatories (NSAIDs; i.e. diclofenac), and progesterone are associated with cyclodextrins. Products containing the association of diclofenac/cyclodextrins are available for subcutaneous, intramuscular, and intravenous administration in doses that range from 25 to 75 mg. Medicinal products containing the association of progesterone/cyclodextrins are indicated for intramuscular and subcutaneous injection at a dose equal to 25 mg. The effects of cyclodextrins have been discussed in the solubility profile and permeability through biological membranes of drug molecules. A literature search was performed in order to give an overview of the pharmacokinetic characteristics, and efficacy and safety profiles of diclofenac/hydroxypropyl-β-cyclodextrin (HPβCD) and progesterone/HPβCD associations. The results of more than 20 clinical studies were reviewed. It was suggested that the new diclofenac/HPβCD formulation gives a rapid and effective response to acute pain and, furthermore, has pharmacokinetic and efficacy/safety profiles comparable to other medicinal products not containing cyclodextrins. One of the principal aspects of these new diclofenac formulations is that in lowering the dose (lower than 50 mg) the drugs could be more tolerable, especially in patients with comorbid conditions. Moreover, results of studies investigating the characteristics of progesterone and cyclodextrins showed that the new formulation (progesterone/HPβCD 25 mg solution) has the same bioavailability as other products containing progesterone. It is more rapidly absorbed and allows the achievement of peak plasma concentrations in a shorter time. Finally, the

  14. Cyclodextrins in Asymmetric and Stereospecific Synthesis

    Directory of Open Access Journals (Sweden)

    Fliur Macaev

    2015-09-01

    Full Text Available Since their discovery, cyclodextrins have widely been used as green and easily available alternatives to promoters or catalysts of different chemical reactions in water. This review covers the research and application of cyclodextrins and their derivatives in asymmetric and stereospecific syntheses, with their division into three main groups: (1 cyclodextrins promoting asymmetric and stereospecific catalysis in water; (2 cyclodextrins’ complexes with transition metals as asymmetric and stereospecific catalysts; and (3 cyclodextrins’ non-metallic derivatives as asymmetric and stereospecific catalysts. The scope of this review is to systematize existing information on the contribution of cyclodextrins to asymmetric and stereospecific synthesis and, thus, to facilitate further development in this direction.

  15. CYCLODEXTRINS - FIELFS OF APPLICATION. PART II

    Directory of Open Access Journals (Sweden)

    Gh. Duca

    2012-12-01

    Full Text Available This paper represents an analysis of potential and current applications of cyclodextrins as biologically active substances in medicine. The main applications described here include use of cyclodextrins as agents that form inclusion complexes with endogenous substances (membrane lipids, cellular cholesterol, agents that form inclusion complexes with exogenous substances with their man role as guest molecules (sugammadex, FBCx, agents that block endogenous and exogenous macromolecules (ion channels, anthrax toxin, α-hemolysin, and agents which activity is based on the chemical nature of them and of their derivatives (cyclodextrin polysulphate derivatives. The fi rst classifi cation for medically important biological activity of cyclodextrins has been proposed.

  16. Cyclodextrin-Based Solid-Gas Clathrates

    NARCIS (Netherlands)

    Pereva, Stiliana; Himitliiska, Tsveta; Spassov, Tony; Stoyanov, S.D.; Arnaudov, L.N.; Dudev, Todor

    2015-01-01

    "Cyclodextrin-gas" clathrates were obtained by crystallization from water solution of α-, β-, and γ-cyclodextrins (CDs) under pressure of the gas to be entrapped into the CD molecules. When the pressure is released, these clathrates are stable at ambient conditions and dissociate at elevated

  17. The effects of cyclodextrins on drug release from fatty suppository bases : III. Application of cyclodextrin derivatives

    NARCIS (Netherlands)

    Frijlink, H.W.; Paiotti, S.; Eissens, Anko; Lerk, C.F.

    1992-01-01

    The complexation of both n-butyl-4-aminobenzoate and diazepam with dimethyl-beta-cyclodextrin and hydroxypropyl-beta-cyclodextrin, respectively, was studied. Solid complexes were prepared by freeze-drying. The complexes were incorporated in fatty suppositories and drug release was studied, both in

  18. Effects of cyclodextrin glycosiltransferase modified starch and cyclodextrins on plasma glucose and lipids metabolism in mice

    Science.gov (United States)

    The potential functional and nutritional benefits of granular starch treated with cyclodextrin glycosyltransferase (CGTase) and the released cyclodextrins (CDs) were explored in in vivo studies. The metabolic effects of diets in the C57BL/6J mouse containing native and enzymatically modified corn st...

  19. Displacement of Drugs From Cyclodextrin Complexes by Bile Salts

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Westh, Peter; Holm, Rene

    2016-01-01

    of drug from the cyclodextrin cavity by bile salts present in the small intestine. As bile salts in the intestine are present at concentrations above the critical micelle concentration, an understanding of the interaction between cyclodextrins and bile salts at such supramicellar concentrations (SMC......) is required for a better biopharmaceutical understanding of the release mechanism from orally dosed cyclodextrin complexes. To address this, experiments were conducted by isothermal titration calorimetry to determine how various b-cyclodextrins and bile salt interacts at SMC. Combined analysis of the current...... results and earlier data demonstrated that direct interactions between bile salt micelles and cyclodextrin were negligible. From this knowledge, an extended form of the UCD was suggested to describe the concentration of cyclodextrins to achieve full drug solubilization in the intestine where bile salts...

  20. Synthesis of polyrotaxanes from acetyl-β-cyclodextrin

    Science.gov (United States)

    Ristić, I. S.; Nikolić, L.; Nikolić, V.; Ilić, D.; Budinski-Simendić, J.

    2011-12-01

    Polyrotaxanes are intermediary products in the synthesis of topological gels. They are created by inclusion complex formation of hydrophobic linear macromolecules with cyclodextrins or their derivatives. Then, pairs of cyclodextrin molecules with covalently linkage were practically forming the nodes of the semi-flexible polymer network. Such gels are called topological gels and they can absorb huge quantities of water due to the net flexibility allowing the poly(ethylene oxide) chains to slide through the cyclodextrin cavities, without being pulled out altogether. For polyrotaxane formation poly(ethylene oxide) was used like linear macromolecules. There are hydroxyl groups at poly(ethylene oxide) chains, whereby the linking of the voluminous molecules should be made. To avoid the reaction of cyclodextrin OH groups with stoppers, they should be protected by, e.g., acetylation. In this work, the acetylation of the OH groups of β-cyclodextrin was performed by acetic acid anhydride with iodine as the catalyst. The acetylation reaction was assessed by the FTIR and HPLC method. By the HPLC analysis was found that the acetylation was completed in 20 minutes. Inserting of poly(ethylene oxide) with 4000 g/mol molecule mass into acetyl-β-cyclodextrin with 2:1 poly(ethylene oxide) monomer unit to acetyl-β-cyclodextrin ratio was also monitored by FTIR, and it was found that the process was completed in 12 h at the temperature of 10°C. If the process is performed at temperatures above 10°C, or for periods longer than 12 hours, the process of uncontrolled hydrolysis of acetate groups was initiated.

  1. Selective discrimination of cyclodextrin diols using cyclic sulfates

    DEFF Research Database (Denmark)

    Petrillo, Marta; Marinescu, Lavinia; Rousseau, Cyril

    2009-01-01

    A method for selective monofunctionalition of readily available cyclodextrin diols (2(A-F),3(A-F),6(B,C,E,F)-hexadeca-O-benzyl-alpha-cyclodextrin and 2(A-G),3(A-G),6(B,C,E-G)-nonadeca-O-benzyl-beta-cyclodextrin) by regioselective nucleophilic opening of their cyclic sulfates is presented. Although...

  2. Cyclodextrin Controlled Release of Poorly Water-Soluble Drugs from Hydrogels

    DEFF Research Database (Denmark)

    Woldum, Henriette Sie; Madsen, Flemming; Larsen, Kim Lambertsen

    2008-01-01

    The effect of 2-hydroxypropyl- -cyclodextrin and -cyclodextrin on the release of ibuprofen, ketoprofen and prednisolone was studied. Stability constants calculated for inclusion complexes show size dependence for complexes with both cyclodextrins. Hydrogels were prepared by ultraviolet irradiation...... and release of each model drug was studied. For drugs formulated using cyclodextrins an increase in the achievable concentration and in the release from hydrogels was obtained due to increased solubility, although the solubility of all -cyclodextrin complexes was limited. The load also was increased...

  3. Solubility profiles, hydration and desolvation of curcumin complexed with γ-cyclodextrin and hydroxypropyl-γ-cyclodextrin

    Science.gov (United States)

    Shityakov, Sergey; Salmas, Ramin Ekhteiari; Durdagi, Serdar; Roewer, Norbert; Förster, Carola; Broscheit, Jens

    2017-04-01

    In this study, we investigated curcumin (CUR) solubility profiles and hydration/desolvation effects of this substance formulated with γ-cyclodextrin (γ-CD) and hydroxypropyl-γ-cyclodextrin (HP-γ-CD) excipients. The CUR/HP-γ-CD complex was found to be more stable in solution with the highest apparent stability constant for CUR/HP-γ-CD (Kc = 1.58*104 M-1) as the more soluble form in distilled water. The in silico calculations, including molecular docking, Monte Carlo (MC), and molecular dynamics (MD) simulations, indicated that water molecules play an important role in host-guest complexation mediating the CUR binding to cyclodextrins via hydrogen bond formations. The CUR hydration/desolvation effects contributed to the complex formation by elevating the CUR binding affinity to both CDs. The CUR/HP-γ-CD complex after the CUR hydration was determined with a minimal Gibbs free energy of binding (ΔGbind = -9.93 kcal*mol-1) due to the major hydrophobic (vdW) forces. Overall, the results of this study can aid a development of cyclodextrin-based drug delivery vectors, signifying the importance of water molecules during the formulation processes.

  4. Enhancement of norfloxacin solubility via inclusion complexation with β-cyclodextrin and its derivative hydroxypropyl-β-cyclodextrin

    Directory of Open Access Journals (Sweden)

    Gabriel Onn Kit Loh

    2016-08-01

    Full Text Available The objectives of the study were to investigate the effects of β-cyclodextrin (βCD and hydroxypropyl-β-cyclodextrin (HPβCD on the solubility and dissolution rate of norfloxacin prepared using three different methods, at drug to cyclodextrin weight ratios of 1:1, 1:2, 1:4 and 1:8. All the methods increased the solubility and dissolution rate of norfloxacin via inclusion complexation with βCD and HPβCD. Norfloxacin was converted from crystalline to amorphous form through inclusion complexation. Solvent evaporation method was the most effective method in terms of norfloxacin solubilisation, while inclusion complex of HPβCD has higher solubility than βCD complex when prepared using the same procedure.

  5. Grape Preservation Using Chitosan Combined with β-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    Yu Youwei

    2013-01-01

    Full Text Available The effect of 1% chitosan combined with 2% β-cyclodextrin to the preservation of fresh grapes under ambient temperature was investigated. The results indicated that the hydrogen bond formed between the hydroxyl group of β-cyclodextrin and the amidogen or hydroxyl group of chitosan and the crystal form of chitosan was also changed when cyclodextrin was doped into chitosan coating. The compound coating could prolong the shelf life of grapes, maintain lower respiration rate and higher activities of superoxide dismutase, peroxidase, and catalase during storage time, and restrain weight loss and malonaldehyde content increase. Coating grapes with chitosan + β-cyclodextrin was a good method in postharvested grape preservation.

  6. Cyclodextrin Nanoparticles Bearing 8-Hydroxyquinoline Ligands as Multifunctional Biomaterials.

    Science.gov (United States)

    Oliveri, Valentina; Bellia, Francesco; Vecchio, Graziella

    2017-03-28

    Cyclodextrins are used as building blocks for the development of a host of polymeric biomaterials. The cyclodextrin polymers have found numerous applications as they exhibit unique features such as mechanical properties, stimuli responsiveness and drug loading ability. Notwithstanding the abundance of cyclodextrin polymers studied, metal-chelating polymers based on cyclodextrins have been poorly explored. Herein we report the synthesis and the characterization of the first metal-chelating β-cyclodextrin polymer bearing 8-hydroxyquinoline ligands. The metal ions (Cu 2+ or Zn 2+ ) can modulate the assembly of the polymer nanoparticles. Moreover, the protective activity of the new chelating polymer against self- and metal-induced Aβ aggregation and free radical species are significantly higher than those of the parent compounds. These synergistic effects suggest that the incorporation of hydroxyquinoline moieties into a soluble β-cyclodextrin polymer could represent a promising strategy to design multifunctional biomaterials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Post monitoring of a cyclodextrin remeditated chlorinated solvent contaminated aquifer

    Science.gov (United States)

    Blanford, W. J.

    2006-12-01

    Hydroxypropyl-â-cyclodextrin (HPâCD) has been tested successfully in the laboratory and in the field for enhanced flushing of low-polarity contaminants from aquifers. The cyclodextrin molecule forms a toroidal structure, which has a hydrophobic cavity. Within this cavity, organic compounds of appropriate shape and size can form inclusion complexes, which is the basis for the use of cyclodextrin in groundwater remediation. The hydrophilic exterior of the molecule makes cyclodextrin highly water-soluble. The solubility of cyclodextrins can be further enhanced by adding functional groups, such as hydroxypropyl groups, to the cyclodextrin core. The aqueous solubility of HPâCD exceeds 950 g/L. These high solubilities are advantageous for field applications because they permit relatively high concentrations of the flushing agent. In order for cyclodextrin to become a feasible remediative alternative, it must be demonstrate a short term resistance to biodegradation during field application, but ultimately biodegrade so as not to pose a long term presence in the aquifer. The potential for degradation of cyclodextrin as well as changes in the chlorinated solvents and groundwater geochemistry were examined during the post monitoring of a field demonstration in a shallow aquifer at Little Creek Naval Amphibious Base in Virginia. It was found that a portion of the cyclodextrin remaining in the aquifer after the cessation of field activities biodegraded during the 425 days of post monitoring. This degradation also led to the degradation of the chlorinated solvents trichloroethylene and 1,1-trichloroethane through both biological and chemical processes. The aquifer remained anaerobic with average dissolved oxygen levels below 0.5 mg/L. Dissolved nitrate and sulfate concentrations within the cyclodextrin plume decreased due their being used as terminal electron acceptors during the degradation of the cyclodextrin. The concentrations of total iron at the field site showed no

  8. Characterization of aspartame-cyclodextrin complexation.

    Science.gov (United States)

    Sohajda, Tamás; Béni, Szabolcs; Varga, Erzsébet; Iványi, Róbert; Rácz, Akos; Szente, Lajos; Noszál, Béla

    2009-12-05

    The inclusion complex formation of aspartame (guest) and various cyclodextrins (host) were examined using 1H NMR titration and capillary electrophoresis. Initially the protonation constants of aspartame were determined by NMR-pH titration with in situ pH measurement to yield log K1=7.83 and log K2=2.96. Based on these values the stability of the complexes formed by aspartame and 21 different cyclodextrins (CDs) were studied at pH 2.5, pH 5.2 and pH 9.0 values where aspartame exists predominantly in monocationic, zwitterionic and monoanionic form, respectively. The host cyclodextrin derivatives differed in various sidechains, degree of substitution, charge and purity so that the effect of these properties could be examined systematically. Concerning size, the seven-membered beta-cyclodextrin and its derivatives have been found to be the most suitable host molecules for complexation. Highest stability was observed for the acetylated derivative with a degree of substitution of 7. The purity of the CD enhanced the complexation while the degree of substitution did not provide obvious consequences. Finally, geometric aspects of the inclusion complex were assessed by 2D ROESY NMR and molecular modelling which proved that the guest's aromatic ring enters the wider end of the host cavity.

  9. Cyclodextrin-based nanosponges as drug carriers

    Directory of Open Access Journals (Sweden)

    Francesco Trotta

    2012-11-01

    Full Text Available Cyclodextrin-based nanosponges, which are proposed as a new nanosized delivery system, are innovative cross-linked cyclodextrin polymers nanostructured within a three-dimensional network. This type of cyclodextrin polymer can form porous insoluble nanoparticles with a crystalline or amorphous structure and spherical shape or swelling properties. The polarity and dimension of the polymer mesh can be easily tuned by varying the type of cross-linker and degree of cross-linking. Nanosponge functionalisation for site-specific targeting can be achieved by conjugating various ligands on their surface. They are a safe and biodegradable material with negligible toxicity on cell cultures and are well-tolerated after injection in mice. Cyclodextrin-based nanosponges can form complexes with different types of lipophilic or hydrophilic molecules. The release of the entrapped molecules can be varied by modifying the structure to achieve prolonged release kinetics or a faster release. The nanosponges could be used to improve the aqueous solubility of poorly water-soluble molecules, protect degradable substances, obtain sustained delivery systems or design innovative drug carriers for nanomedicine.

  10. Novel β-cyclodextrin-eosin conjugates.

    Science.gov (United States)

    Benkovics, Gábor; Afonso, Damien; Darcsi, András; Béni, Szabolcs; Conoci, Sabrina; Fenyvesi, Éva; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin-EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin-EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

  11. Direct investigation of the vectorization properties of amphiphilic cyclodextrins in phospholipid films.

    Science.gov (United States)

    Javierre, Isabelle; Nedyalkov, Mickael; Petkova, Vera; Benattar, Jean Jacques; Weisse, Sandrine; Auzély-Velty, Rachel; Djedaïni-Pilard, Florence; Perly, Bruno

    2002-10-01

    Recently, new cyclodextrin derivatives were synthesized and shown to exhibit strong amphiphilic properties. In this paper, we study the action of these new amphiphilic cyclodextrins on phospholipids. Mixed phospholipid/cyclodextrin derivative films were prepared and studied using X-ray reflectivity for various phospholipid/cyclodextrin ratios. A molar ratio of 3 provides a highly stable film the molecular structure of which has been investigated in detail. The cholesterol tail of the cyclodextrin molecule was found to be anchored into the phospholipid film. The cyclodextrin moieties exposed to the aqueous medium are prone to the addition of the guest molecule Dosulepin, making them of high interest for drug delivery. For this purpose and as an example of a potential application, this cyclodextrin molecular carrier property is also addressed to this complex film architecture.

  12. Supramolecular photocatalyst of RGO-cyclodextrin-TiO2

    International Nuclear Information System (INIS)

    Shen, Jianfeng; Li, Na; Ye, Mingxin

    2013-01-01

    Graphical abstract: Supramolecular photocatalyst of RGO-cyclodextrin-TiO 2 was achieved, which showed high photocatalytic activity and adsorption capacity. Highlights: •Supramolecular photocatalyst of RGO-cyclodextrin-TiO 2 was achieved. •β-CD molecules acted as linkers between RGO and monodisperse TiO 2 nanoparticles. •Reduction of GO and preparation of RGO-cyclodextrin-TiO 2 was simultaneous. •The prepared RGO-cyclodextrin-TiO 2 shows high photocatalytic activity and adsorption capacity. -- Abstract: Reduced graphene oxide (RGO)/β-cyclodextrin (β-CD)/titanium oxide (TiO 2 ) supramolecular photocatalyst was synthesized with a one-pot hydrothermal method. The reducing process was accomplished with the attaching of β-CD and generation of TiO 2 . β-CD acted as a linker between RGO and monodisperse TiO 2 nanoparticles. The structure and composition of the hybrid had been characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, thermal gravimetric analysis, X-ray diffraction and Transmission electron microscopy. The as-prepared RGO-CD-TiO 2 showed significant enhanced performance for phenol and Cr (VI) removal, due to the effective transfer of photo-generated electron from TiO2 to RGO and improved absorbance performance of the hybrid

  13. Preparation, characterization and in vitro dissolution study of Nitrazepam: Cyclodextrin inclusion complex

    Directory of Open Access Journals (Sweden)

    J S Patel

    2012-01-01

    Full Text Available The objectives of this research were to prepare and characterize inclusion complexes of Nitrazepam with Hydroxypropyl-β-cyclodextrin (HPβCD and Sulfobutyl ether β-cyclodextrin (SBEβCD to study the effect of complexation on the dissolution rate of Nitrazepam, a water-insoluble drug. The phase solubility profile of Nitrazepam with Hydroxypropyl- β-cyclodextrin and Sulfobutyl ether β-cyclodextrin was an AP-type, indicating the formation of 2:1 stoichiometric inclusion complexes. Gibbs free energy values were all negative, indicating the spontaneous nature Nitrazepam solubilization and their value decreased with increase in the cyclodextrin concentration, demonstrating that the reaction conditions became more favorable as the concentration of cyclodextrins increased. Complexes of Nitrazepam were prepared with cyclodextrin using various methods such as physical mixing, kneading, spray-drying and lyophilization. The complexes were characterized by Differential scanning calorimetry, Fourier-transform infrared, scanning electron microscopy and powder X-ray diffraction studies. These studies indicated that a complex prepared by lyophilization had successful inclusion of the Nitrazepam molecule into the cyclodextrin cavity. Complexation resulted in a marked improvement in the solubility and wettability of Nitrazepam. Among all the samples, a complex prepared with Sulfobutyl ether β-cyclodextrin by lyophilization had the greatest improvement in the in vitro rate of Nitrazepam dissolution. The mean dissolution time for Nitrazepam decreased significantly after preparing complexes. The similarity factor indicated a significant difference between the release profiles of Nitrazepam from complexes, physical mixtures and plain Nitrazepam. To conclude that, the tablets containing complexes prepared with Cyclodextrins had significant improvement in the release profile of Nitrazepam as compared to tablets containing Nitrazepam without cyclodextrin.

  14. Cyclodextrin-Catalyzed Organic Synthesis: Reactions, Mechanisms, and Applications

    Directory of Open Access Journals (Sweden)

    Chang Cai Bai

    2017-09-01

    Full Text Available Cyclodextrins are well-known macrocyclic oligosaccharides that consist of α-(1,4 linked glucose units and have been widely used as artificial enzymes, chiral separators, chemical sensors, and drug excipients, owing to their hydrophobic and chiral interiors. Due to their remarkable inclusion capabilities with small organic molecules, more recent interests focus on organic reactions catalyzed by cyclodextrins. This contribution outlines the current progress in cyclodextrin-catalyzed organic reactions. Particular emphases are given to the organic reaction mechanisms and their applications. In the end, the future directions of research in this field are proposed.

  15. Inclusion complexes of azadirachtin with native and methylated cyclodextrins: solubilization and binding ability.

    Science.gov (United States)

    Liu, Yu; Chen, Guo-Song; Chen, Yong; Lin, Jun

    2005-06-02

    The inclusion complexation behavior of azadirachtin with several cyclodextrins and their methylated derivatives has been investigated in both solution and the solid state by means of XRD, TG-DTA, DSC, NMR, and UV-vis spectroscopy. The results show that the water solubility of azadirachtin was obviously increased after resulting inclusion complex with cyclodextrins. Typically, beta-cyclodextrin (beta-CD), dimethyl-beta-cyclodextrin (DMbetaCD), permethyl-beta-cyclodextrin (TMbetaCD), and hydroxypropyl-beta-cyclodextrin (HPbetaCD) are found to be able to solubilize azadirachtin to high levels up to 2.7, 1.3, 3.5, and 1.6 mg/mL (calculated as azadirachtin), respectively. This satisfactory water solubility and high thermal stability of the cyclodextrin-azadirachtin complexes, will be potentially useful for their application as herbal medicine or healthcare products.

  16. Cyclodextrin-modified nanodiamond for the sensitive fluorometric determination of doxorubicin in urine based on its differential affinity towards β/γ-cyclodextrins.

    Science.gov (United States)

    Laura Soriano, M; Carrillo-Carrion, Carolina; Ruiz-Palomero, Celia; Valcárcel, Miguel

    2018-01-15

    The manuscript reports on the preparation of β-cyclodextrin-modified nanodiamonds (βCD-ND) for the extraction and preconcentration of the fluorescent anticancer drug doxorubicin (DOX) from biological samples. The inclusion of DOX into the cavities of β- and γ-cyclodextrin (CD) confirms their utility for selective extraction and elution of the drug based on its good fit to the cyclodextrin cavity. Although both larger cyclodextrins (βCD and γCD) accommodate DOX, DOX clearly prefers the bigger γCD cavities. Dispersive micro solid-phase extraction using βCD-ND as sorbent enables the inclusion complexation of DOX. The elution of DOX from βCD-ND cavities occurs with a basic solution of γCD containing 10% acetonitrile owing to the preferential affinity (i.e. optimal fit) of DOX into the larger γCD cavity. DOX is quantified by monitoring its intrinsic fluorescence (exc/em = 475/595 nm). The method can determine DOX in urine with a limit of detection of 18 ng·mL -1 . Recoveries (93.2% and 94.0%) and precision (RSDs of 5.9% and 4.7%) at 100 and 400 ng·mL -1 DOX levels in urine are satisfactory. The matrix effect is negligible even when working with undiluted urine samples. Graphical abstract Nanodiamonds functionalized with β-cyclodextrin (βCD-ND) were used as sorbent for the determination of nanomolar levels of doxorubicin (DOX). It is based on host:guest interactions ruled by different stabilities of DOX within cyclodextrin (CD) cavity-size: βCD/γCD.

  17. Complexation of tauro- and glyco-conjugated bile salts with alpha-cyclodextrin and hydroxypropyl-alpha-cyclodextrin studied by affinity capillary electrophoresis and molecular modelling

    DEFF Research Database (Denmark)

    Holm, Rene; Schönbeck, Jens Christian Sidney; Askjær, Sune

    2011-01-01

    The interaction of the bile salts taurocholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate, and glycochenodeoxycholate present in man, dog, and rat with α-cyclodextrin and 2-hydroxypropyl-α-cyclodextrin was investigated by mobility shift affinity capillary electrop...

  18. Preparation, characterization and in vitro dissolution study of Nitrazepam: Cyclodextrin inclusion complex

    OpenAIRE

    Patel, J. S.; Patel, R. P.

    2012-01-01

    The objectives of this research were to prepare and characterize inclusion complexes of Nitrazepam with Hydroxypropyl-β-cyclodextrin (HPβCD) and Sulfobutyl ether β-cyclodextrin (SBEβCD) to study the effect of complexation on the dissolution rate of Nitrazepam, a water-insoluble drug. The phase solubility profile of Nitrazepam with Hydroxypropyl- β-cyclodextrin and Sulfobutyl ether β-cyclodextrin was an AP-type, indicating the formation of 2:1 stoichiometric inclusion complexes. Gibbs free ene...

  19. Phosphorus-containing cyclodextrins. Characteristics of the synthesis and chemical behaviour

    International Nuclear Information System (INIS)

    Grachev, M K

    2013-01-01

    Published data on the preparation of phosphorus-containing cyclodextrins are summarized. It is demonstrated that some significant features of their synthesis and chemical behaviour are caused by specific supramolecular interactions involving the inner chiral cavity of cyclodextrins capable of incorporating various guests, which often leads to alteration of customary routes of chemical transformations. The possibilities of practical applications of phosphorus-containing cyclodextrins are briefly analyzed. The bibliography includes 89 references

  20. Biodegradable films containing α-tocopherol/β-cyclodextrin complex

    International Nuclear Information System (INIS)

    Motta, Caroline; Martelli, Silvia M.; Soldi, Valdir; Barreto, Pedro L.M.

    2011-01-01

    The growing environmental concern about pollution and the need to reduce dependence of plastic industry in relation to non-renewable resources has increased the interest of both researchers and industry in the use of biopolymers. In this work β-cyclodextrin/α-tocopherol complexes were prepared and characterized. In order to obtain polymeric active biofilms, the β-cyclodextrin/α-tocopherol complex was incorporated into a polymeric matrix of carboxymethylcellulose. The β-cyclodextrin/α-tocopherol complex was characterized through of X-ray diffraction and thermogravimetric analysis. The physicochemical properties of the films incorporated with the complex were evaluated through mechanical and colorimetric analysis and moisture sorption isotherm. (author)

  1. Study on inclusion interaction of piroxicam with β-cyclodextrin derivatives

    Science.gov (United States)

    Xiliang, Guo; Yu, Yang; Guoyan, Zhao; Guomei, Zhang; Jianbin, Chao; Shaomin, Shuang

    2003-12-01

    The inclusion behavior of piroxicam (PX) with β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and carboxymethyl-β-cyclodextrin (CM-β-CD) was investigated by using steady-state fluorescence and nuclear magnetic resonance (NMR) technique. The various factors affecting the inclusion process were examined in detail. The remarkable fluorescence emission enhancement upon addition of CDs suggested that cyclodextrins (CDs) were most suitable for inclusion of the uncharged species of PX. The stoichiometry of the PX-CDs inclusion complexes was 1:1, except for β-CD where a 1:2 inclusion complex was formed. The formation constants showed the strongest inclusion capacity of β-CD. NMR showed the inclusion mode of PX with CDs.

  2. Cyclodextrin-Modified inorganic materials for the construction of nanocarriers.

    Science.gov (United States)

    Cutrone, Giovanna; Casas-Solvas, Juan M; Vargas-Berenguel, Antonio

    2017-10-15

    Inorganic nanoparticles, such as gold, silver, quantum dots and magnetic nanoparticles, offer a promising way to develop multifunctional nanoparticles for biomedical applications. Such nanoparticles have the potential to combine in a single, stable construct various functionalities, simultaneously providing imaging abilities, thermal therapies and the ability to deliver drugs in a targeted fashion. An approach for providing drug loading abilities to these inorganic nanoparticles consists in the modification of their surface with a coating of cyclodextrins, and thereby endowing the nanoparticles with the potential of functioning as drug nanocarriers. This review presents the advances carried out in the preparation of cyclodextrin-contained gold, silver, quantum dot and magnetic nanoparticles as well as their applications as drug nanocarriers. The nanoparticle surface can be modified incorporating cyclodextrin moieties, (i) in situ during the synthesis of the nanoparticles, either using the cyclodextrin as reducing agent or as stabilizer; or (ii) in a post-synthetic stage. The cyclodextrin coating contributes to provide biocompatibility to the nanoparticles and to reduce their cytotoxicity. Cyclodextrin-modified nanoparticles display a multivalent presentation of quasi-hydrophobic cavities that enables, not only drug loading in a non-covalent manner, but also the non-covalent assembly of targeting motifs and optical probes. This paper also provides an overview of some of the reported applications including the in vitro studies and, to a lesser extent, in vivo studies on the drug-loaded nanoparticles behavior. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Influence of lipophilicity on drug-cyclodextrin interactions: A calorimetric study

    International Nuclear Information System (INIS)

    Waters, Laura J.; Bedford, Susan; Parkes, Gareth M.B.; Mitchell, J.C.

    2010-01-01

    This study presents a systematic investigation of the interaction of three functionally related drugs, ibuprofen, ketoprofen and flurbiprofen, with two distinct forms of cyclodextrin at three specific temperatures, 298, 303 and 310 K using isothermal titration calorimetry (ITC). Although all three pharmaceutical compounds have similar pKa values, they exhibit widely differing lipophilicities. While previous authors have presented data regarding the binding of flurbiprofen and ibuprofen with β-cyclodextrin, this is the first report of the interaction of all three drug substances with β-cyclodextrin and 2-(hydroxypropyl)-β-cyclodextrin at controlled pH and temperature. For all scenarios, the associated changes in Gibbs free energy, enthalpy and entropy are presented alongside the stoichiometry and binding constants concerned. In all cases the binding was found to occur at a 1:1 ratio with an associated negative enthalpy and Gibbs free energy with the formation of the complex enthalpically, rather than entropically driven. The data further demonstrates a clear relationship between the thermodynamic behaviour and log P of the drug molecules. This work confirms the suitability of ITC to determine thermodynamic data for drug-cyclodextrin complex formations and provides an insight into the selection of appropriate cyclodextrins for bespoke pharmaceutical formulations.

  4. Influence of lipophilicity on drug-cyclodextrin interactions: A calorimetric study

    Energy Technology Data Exchange (ETDEWEB)

    Waters, Laura J., E-mail: l.waters@hud.ac.uk [School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH (United Kingdom); Bedford, Susan; Parkes, Gareth M.B. [School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH (United Kingdom); Mitchell, J.C. [Medway Sciences, School of Science, University of Greenwich at Medway, Chatham Maritime, Kent ME4 4TB (United Kingdom)

    2010-11-20

    This study presents a systematic investigation of the interaction of three functionally related drugs, ibuprofen, ketoprofen and flurbiprofen, with two distinct forms of cyclodextrin at three specific temperatures, 298, 303 and 310 K using isothermal titration calorimetry (ITC). Although all three pharmaceutical compounds have similar pKa values, they exhibit widely differing lipophilicities. While previous authors have presented data regarding the binding of flurbiprofen and ibuprofen with {beta}-cyclodextrin, this is the first report of the interaction of all three drug substances with {beta}-cyclodextrin and 2-(hydroxypropyl)-{beta}-cyclodextrin at controlled pH and temperature. For all scenarios, the associated changes in Gibbs free energy, enthalpy and entropy are presented alongside the stoichiometry and binding constants concerned. In all cases the binding was found to occur at a 1:1 ratio with an associated negative enthalpy and Gibbs free energy with the formation of the complex enthalpically, rather than entropically driven. The data further demonstrates a clear relationship between the thermodynamic behaviour and log P of the drug molecules. This work confirms the suitability of ITC to determine thermodynamic data for drug-cyclodextrin complex formations and provides an insight into the selection of appropriate cyclodextrins for bespoke pharmaceutical formulations.

  5. Inclusion and Functionalization of Polymers with Cyclodextrins: Current Applications and Future Prospects

    Directory of Open Access Journals (Sweden)

    Christian Folch-Cano

    2014-09-01

    Full Text Available The numerous hydroxyl groups available in cyclodextrins are active sites that can form different types of linkages. They can be crosslinked with one another, or they can be derivatized to produce monomers that can form linear or branched networks. Moreover, they can form inclusion complexes with polymers and different substrates, modifying their physicochemical properties. This review shows the different applications using polymers with cyclodextrins, either by forming inclusion complexes, ternary complexes, networks, or molecularly imprinted polymers (MIPs. On one hand, the use of cyclodextrins enhances the properties of each polymer, and on the other the use of polymers decreases the amount of cyclodextrins required in different formulations. Both cyclodextrins and polymers contribute synergistically in several applications such as pharmacological, nutritional, environmental, and other industrial fields. The use of polymers based on cyclodextrins is a low cost easy to use potential tool with great future prospects.

  6. Effect of ?-cyclodextrin on Rheological Properties of some Viscosity Modifiers

    OpenAIRE

    Rao, G. Chandra Sekhara; Ramadevi, K.; Sirisha, K.

    2014-01-01

    Cyclodextrins are a group of novel excipients, extensively used in the present pharmaceutical industry. Sometimes they show significant interactions with other conventional additives used in the formulation of dosage forms. The effect of β-cyclodextrin on the rheological properties of aqueous solutions of some selected viscosity modifiers was studied in the present work. β-cyclodextrin showed two different types of effects on the rheology of the selected polymers. In case of natural polymers ...

  7. Molecular printboards: monolayers of beta-cyclodextrins on silicon oxide surfaces.

    Science.gov (United States)

    Onclin, Steffen; Mulder, Alart; Huskens, Jurriaan; Ravoo, Bart Jan; Reinhoudt, David N

    2004-06-22

    Monolayers of beta-cyclodextrin host molecules have been prepared on SiO2 surfaces. An ordered and stable cyano-terminated monolayer was modified in three consecutive surface reactions. First, the cyanide groups were reduced to their corresponding free amines using Red Al as a reducing agent. Second, 1,4-phenylene diisothiocyanate was used to react with the amine monolayer where it acts as a linking molecule, exposing isothiocyanates that can be derivatized further. Finally, per-6-amino beta-cyclodextrin was reacted with these isothiocyanate functions to yield a monolayer exposing beta-cyclodextrin. All monolayers were characterized by contact angle measurements, ellipsometric thickness measurements, Brewster angle Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry, which indicate the formation of a densely packed cyclodextrin surface. It was demonstrated that the beta-cyclodextrin monolayer could bind suitable guest molecules in a reversible manner. A fluorescent molecule (1), equipped with two adamantyl groups for complexation, was adsorbed onto the host monolayer from solution to form a monolayer of guest molecules. Subsequently, the guest molecules were desorbed from the surface by competition with increasing beta-cyclodextrin concentration in solution. The data were fitted using a model. An intrinsic binding constant of 3.3 +/- 1 x 10(5) M(-1) was obtained, which corresponds well to previously obtained results with a divalent guest molecule on beta-cyclodextrin monolayers on gold. In addition, the number of guest molecules bound to the host surface was determined, and a surface coverage of ca. 30% was found.

  8. Methylated β-Cyclodextrins

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Madsen, Jens Christian

    2011-01-01

    The complexation of 6 bile salts with various methylated β-cyclodextrins was studied to elucidate how the degree and pattern of substitution affects the binding. The structures of the CDs were determined by mass spectrometry and NMR techniques, and the structures of the inclusion complexes were...

  9. Lanthanide-cyclodextrin complexes as probes for elucidating optical purity by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, T.J.; Bogyo, M.S.; Lebeau, E.L. (Bates College, Lewiston, ME (United States))

    1994-06-01

    A multidentate ligand is bonded to cyclodextrins by the reaction of diethylenetriaminepentaacetic dianhydride with 6-mono- and 2-mono(ethylenediamine) derivatives of cyclodextrin. Adding Dy(III) to the cyclodextrin derivatives enhances the enantiomeric resolution in the [sup 1]H NMR spectra of carbionoxamine maleate, doxylamine succinate, pheniramine maleate, propranolol hydrochloride, and tryptophan. The enhancement is more pronounced with the secondary derivative. The Dy(III)-induced shifts can be used to elucidate the geometry of cyclodextrin-substrate inclusion complexes. Lanthanide-induced shifts are reported for complexes of aspartame, tryptophan, propranolol, and 1-anilino-8-naphthalenesulfonate with cyclodextrins, and the relative magnitudes of the shifts agree with previously reported structures of the complexes. 37 refs., 9 figs., 5 tabs.

  10. Synthesis of molecular imprinted beta cyclodextrins oligomers in water

    DEFF Research Database (Denmark)

    Yu, Donghong; Nielsen, Anne Louise; Bach, Lone

    2003-01-01

    compounds in aqueous solution and, therefore, molecular imprinting of cyclodextrins polymers in aqueous solution is of great interest. In this paper, molecular imprinting of beta cyclodextrins has been performed in water by use of diiodobenzene as template and epichlorohydrin as a crosslinker. Inclusion...

  11. Synthesis and characterization of new polyamino-cyclodextrin materials.

    Science.gov (United States)

    Lo Meo, Paolo; D'Anna, Francesca; Gruttadauria, Michelangelo; Riela, Serena; Noto, Renato

    2012-01-10

    With the aim of the synthesis of chemically modified cyclodextrins bearing polyamine pendant groups, potentially useful as capping agents for the preparation of nanosized metal systems or as auxiliaries for gene transfection, the reaction between the heptakis-(6-iodo)-(6-deoxy)-β-cyclodextrin and various polyamines has been explored. This synthetic approach allows obtaining materials constituted by mixtures of cyclodextrins, having different degrees of substitution, which were satisfactorily characterized by means of various complementary techniques (ESI-MS, NMR, potentiometric titration). The products obtained were successfully subjected to preliminary tests for their binding abilities towards suitable organic guests and as capping agents for the preparation of stable silver nanoparticles. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Study of vitamin A derivative complexation in natural and modified cyclodextrins

    International Nuclear Information System (INIS)

    Weisse, Sandrine

    1999-01-01

    This research thesis reports a test of solubilisation and stabilisation of retinol, a highly hydrophobic and unsteady molecule, by natural or modified cyclodextrins. The author first recalls retinol physical-chemical characteristics, and then evokes the different techniques (other than cyclodextrins) used to modify these characteristics. Then, the author addresses the complexes of inclusion of retinol in cyclodextrins, and the associated characterization techniques [fr

  13. Pharmaceutical applications of cyclodextrins: basic science and product development.

    Science.gov (United States)

    Loftsson, Thorsteinn; Brewster, Marcus E

    2010-11-01

    Drug pipelines are becoming increasingly difficult to formulate. This is punctuated by both retrospective and prospective analyses that show that while 40% of currently marketed drugs are poorly soluble based on the definition of the biopharmaceutical classification system (BCS), about 90% of drugs in development can be characterized as poorly soluble. Although a number of techniques have been suggested for increasing oral bioavailability and for enabling parenteral formulations, cyclodextrins have emerged as a productive approach. This short review is intended to provide both some basic science information as well as data on the ability to develop drugs in cyclodextrin-containing formulations. There are currently a number of marketed products that make use of these functional solubilizing excipients and new product introduction continues to demonstrate their high added value. The ability to predict whether cyclodextrins will be of benefit in creating a dosage form for a particular drug candidate requires a good working knowledge of the properties of cyclodextrins, their mechanism of solubilization and factors that contribute to, or detract from, the biopharmaceutical characteristics of the formed complexes. We provide basic science information as well as data on the development of drugs in cyclodextrin-containing formulations. Cyclodextrins have emerged as an important tool in the formulator's armamentarium to improve apparent solubility and dissolution rate for poorly water-soluble drug candidates. The continued interest and productivity of these materials bode well for future application and their currency as excipients in research, development and drug product marketing. © 2010 The Authors. Journal compilation © 2010 Royal Pharmaceutical Society of Great Britain.

  14. Cyclodextrins in Food Technology and Human Nutrition: Benefits and Limitations.

    Science.gov (United States)

    Fenyvesi, É; Vikmon, M; Szente, L

    2016-09-09

    Cyclodextrins are tasteless, odorless, nondigestible, noncaloric, noncariogenic saccharides, which reduce the digestion of carbohydrates and lipids. They have low glycemic index and decrease the glycemic index of the food. They are either non- or only partly digestible by the enzymes of the human gastrointestinal (GI) tract and fermented by the gut microflora. Based on these properties, cyclodextrins are dietary fibers useful for controlling the body weight and blood lipid profile. They are prebiotics, improve the intestinal microflora by selective proliferation of bifidobacteria. These antiobesity and anti-diabetic effects make them bioactive food supplements and nutraceuticals. In this review, these features are evaluated for α-, β- and γ-cyclodextrins, which are the cyclodextrin variants approved by authorities for food applications. The mechanisms behind these effects are reviewed together with the applications as solubilizers, stabilizers of dietary lipids, such as unsaturated fatty acids, phytosterols, vitamins, flavonoids, carotenoids and other nutraceuticals. The recent applications of cyclodextrins for reducing unwanted components, such as trans-fats, allergens, mycotoxins, acrylamides, bitter compounds, as well as in smart active packaging of foods are also overviewed.

  15. (13)C and (15)N solid-state NMR studies on albendazole and cyclodextrin albendazole complexes.

    Science.gov (United States)

    Ferreira, M João G; García, A; Leonardi, D; Salomon, Claudio J; Lamas, M Celina; Nunes, Teresa G

    2015-06-05

    (13)C and (15)N solid-state nuclear magnetic resonance (NMR) spectra were recorded from albendazole (ABZ) and from ABZ:β-cyclodextrin, ABZ:methyl-β-cyclodextrin, ABZ:hydroxypropyl-β-cyclodextrin and ABZ:citrate-β-cyclodextrin, which were prepared by the spray-drying technique. ABZ signals were typical of a crystalline solid for the pure drug and of an amorphous compound obtained from ABZ:cyclodextrin samples. Relevant spectral differences were correlated with chemical interaction between ABZ and cyclodextrins. The number and type of complexes revealed a strong dependence on the cyclodextrin group substituent. Solid-state NMR data were consistent with the presence of stable inclusion complexes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Circularly Polarized Luminescence from a Pyrene-Cyclodextrin Supra-Dendron.

    Science.gov (United States)

    Zhang, Yuening; Yang, Dong; Han, Jianlei; Zhou, Jin; Jin, Qingxian; Liu, Minghua; Duan, Pengfei

    2018-05-22

    Soft nanomaterials with circularly polarized luminescence (CPL) have been currently attracting great interest. Here, we report a pyrene-containing π-peptide dendron hydrogel, which shows 1D and 2D nanostructures with varied CPL activities. It was found that the individual dendrons formed hydrogels in a wide pH range (3-12) and self-assembled into helices with pH-tuned pitches. Through chirality transfer, the pyrene unit could show CPL originated from both the monomer and excimer bands. When cyclodextrin was introduced, different supra-dendrons were obtained with β-cyclodextrin (PGAc@β-CD) and γ-cyclodextrin (PGAc@γ-CD) through host-guest interactions, respectively. Interestingly, the PGAc@β-CD and PGAc@γ-CD supra-dendrons self-assembled into 2D nanosheet and entangled nanofibers, respectively, showing cyclodextrin induced circularly polarized emission from both the monomer and excimer bands of the pyrene moiety. Thus, through a simple host-guest interaction, both the nanostructures and the chiroptical activities could be modulated.

  17. Spectrofluorimetric determination of stoichiometry and association constants of the complexes of harmane and harmine with beta-cyclodextrin and chemically modified beta-cyclodextrins.

    Science.gov (United States)

    Martín, L; León, A; Olives, A I; Del Castillo, B; Martín, M A

    2003-06-13

    The association characteristics of the inclusion complexes of the beta-carboline alkaloids harmane and harmine with beta-cyclodextrin (beta-CD) and chemically modified beta-cyclodextrins such as hydroxypropyl-beta-cyclodextrin (HPbeta-CD), 2,3-di-O-methyl-beta-cyclodextrin (DMbeta-CD) and 2,3,6-tri-O-methyl-beta-cyclodextrin (TMbeta-CD) are described. The association constants vary from 112 for harmine/DMbeta-CD to 418 for harmane/HPbeta-CD. The magnitude of the interactions between the host and the guest molecules depends on the chemical and geometrical characteristics of the guest molecules and therefore the association constants vary for the different cyclodextrin complexes. The steric hindrance is higher in the case of harmine due to the presence of methoxy group on the beta-carboline ring. The association obtained for the harmane complexes is stronger than the one observed for harmine complexes except in the case of harmine/TMbeta-CD. Important differences in the association constants were observed depending on the experimental variable used in the calculations (absolute value of fluorescence intensity or the ratio between the fluorescence intensities corresponding to the neutral and cationic forms). When fluorescence intensity values were considered, the association constants were higher than when the ratio of the emission intensity for the cationic and neutral species was used. These differences are a consequence of the co-existence of acid-base equilibria in the ground and in excited states together with the complexation equilibria. The existence of a proton transfer reaction in the excited states of harmane or harmine implies the need for the experimental dialysis procedure for separation of the complexes from free harmane or harmine. Such methodology allows quantitative results for stoichiometry determinations to be obtained, which show the existence of both 1:1 and 1:2 beta-carboline alkaloid:CD complexes with different solubility properties.

  18. Relation between structure and organisation properties of new amphiphilic cyclodextrins

    International Nuclear Information System (INIS)

    Moutard, Stephane

    2003-01-01

    Since a number of years, special attention and efforts have been made to prepare amphiphilic cyclodextrins (CDs) with the objective to use them to obtain supramolecular assemblies as such or in the presence of preformed lipidic structures. The aim of these investigation is in both cases to combine the size specificity of cyclodextrins for guests and the transport properties of phospho-lipidic structures. The final objects could be of importance to transport or target biologically relevant molecules such as drugs using new galenic formulations. In a first step, a new family of amphiphilic CDs was prepared from a pure phospholipids (DMPE) onto cyclodextrins or methylated derivatives through a spacing arm. The afforded compounds (phospholipidyl-cyclodextrins) were fully characterized by high field NMR and high resolution mass spectrometry. The methylated derivatives were shown to self-organize in water with low CMC to form fluctuating micellar fibers retaining the inclusion capacity of the cyclodextrin cavities. The interactions of these compounds with membrane systems were investigated as black films using X-ray reflectivity and by evaluation of their detergent power towards model DMPC liposomes. Their ability to cross over the Blood Brain Barrier was evidenced by a new approach making use of novel immuno-enzymatic assays. In a second step, a new class of amphiphilic cyclodextrins was considered (peptidolipidyl-cyclodextrins). Although they are structurally similar to phospholipidyl-CDs, their preparation overcomes the tedious steps of the later and lead to a considerable versatility in terms of the number of possible molecules to be prepared. Moreover, the stability problems encountered with phospholipids are avoided. Several examples have been prepared, fully characterized and their organization properties investigated by the determination of CMC and by deuterium NMR on a pure and homogeneous mixed peptidolipidyl-CD / DMPC lamellar phase. This novel class of

  19. Adsorption of environmental pollutants using magnetic hybrid nanoparticles modified with β-cyclodextrin

    International Nuclear Information System (INIS)

    Wang, Niejun; Zhou, Lilin; Guo, Jun; Ye, Qiquan; Lin, Jin-Ming; Yuan, Jinying

    2014-01-01

    Graft through strategy was utilized to coat magnetic Fe 3 O 4 nanoparticles with poly(glycidyl methacrylate) using ordinary radical polymerization and then β-cyclodextrin was linked onto the surface of nanoparticles. With these nanoparticles modified with cyclodextrin groups, adsorption of two model environmental pollutants, bisphenol A and copper ions, was studied. Host–guest interactions between cyclodextrin and aromatic molecules had a great contribution to the adsorption of bisphenol A, while multiple hydroxyls of cyclodextrin also helped the adsorption of copper ions. These magnetic nanoparticles could be applied in the elimination, enrichment and detection of some environmental pollutants.

  20. SIKLODEKSTRIN GLIKOSIL TRANSFERASE DAN PEMANFAATANNYA DALAM INDUSTRI [Cyclodextrin Glycosyl Transferase and its application in industries

    Directory of Open Access Journals (Sweden)

    Budiasih Wahyuntari

    2005-12-01

    Full Text Available Cyclodextrin glycosyl transferase (CGT-ase is mainly produced by Bacilli. Systematical name of the enzyme is E.C. 2.4.1.19 a-1,4 glucan-4-glycosyl transferase. The enzyme catalyzes hydrolysis of starch intramolecular, and intermolecular transglycosylation of a-1,4, glucan chains. Cyclodextrins are a-1,4 linked cyclic oligosaccharides resulting from enzymatic degradation of starch by cyclodextrin glycosyl transferase through untramolecular transglycosylation. The major cyclodextrins are made up of 6, 7 and 8 glucopyranose units which are known as a-, b-, and y-cyclodextrin. All CGT-ase catalyze three kinds of cyclodextrins, the proportion of the cyclodextrins depends on the enzyme source and reaction conditions. The intermolecular transglycosylation ability of the enzyme has been applied in transfering glycosyl residues into suitable acceptor. Transglycosylation by the enzymes have been tested to improve solubility of some flavonoids and to favor precipitation ci some glycosides.

  1. Anti-aggregatory effect of cyclodextrins in the refolding process of recombinant growth hormones from Escherichia coli inclusion bodies

    DEFF Research Database (Denmark)

    Bajorunaite, Egle; Cirkovas, Andrejus; Radzevicius, Kostas

    2009-01-01

    Cyclodextrins with different ring size and ring substituents were tested for recombinant mink and porcine growth hormones aggregation suppression in the refolding process from Escherichia coli inclusion bodies. Methyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin show a positive effect...... on the aggregation suppression of both proteins. The influence of different methyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin concentrations on the renaturation yield of both growth hormones was investigated. Moreover, methyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin suppress not only folding...

  2. Equilibrium location for spherical DNA and toroidal cyclodextrin

    Science.gov (United States)

    Sarapat, Pakhapoom; Baowan, Duangkamon; Hill, James M.

    2018-05-01

    Cyclodextrin comprises a ring structure composed of glucose molecules with an ability to form complexes of certain substances within its central cavity. The compound can be utilised for various applications including food, textiles, cosmetics, pharmaceutics, and gene delivery. In gene transfer, the possibility of forming complexes depends upon the interaction energy between cyclodextrin and DNA molecules which here are modelled as a torus and a sphere, respectively. Our proposed model is derived using the continuum approximation together with the Lennard-Jones potential, and the total interaction energy is obtained by integrating over both the spherical and toroidal surfaces. The results suggest that the DNA prefers to be symmetrically situated about 1.2 Å above the centre of the cyclodextrin to minimise its energy. Furthermore, an optimal configuration can be determined for any given size of torus and sphere.

  3. Imprinting of Phenylalanine ethyl ester in cyclodextrin polymers in aqueous solution

    DEFF Research Database (Denmark)

    Detcheva, Anna Hr.; Yu, Donghong; Larsen, Kim Lambertsen

    During the last decades there has been a wide interest of developing molecularly imprinted polymers, which selectively can recognize small molecules. Cyclodextrins offer relatively strong binding site of a wide range of small molecules in water and molecular imprinted polymers of these have...... previously been produced with some success. Nevertheless most molecules of interest for molecular imprinting are too samll to accommodate more than one cyclodextrin per molecule and thus limited selectivity may be expected. In order to improve the selectivity of cyclodextrin based molecular imprinted polymer...

  4. Formation of nanoparticles by cooperative inclusion between (S-camptothecin-modified dextrans and β-cyclodextrin polymers

    Directory of Open Access Journals (Sweden)

    Thorbjørn Terndrup Nielsen

    2015-01-01

    Full Text Available Novel (S-camptothecin–dextran polymers were obtained by “click” grafting of azide-modified (S-camptothecin and alkyne-modified dextrans. Two series based on 10 kDa and 70 kDa dextrans were prepared with a degree of substitution of (S-camptothecin between 3.1 and 10.2%. The binding properties with β-cyclodextrin and β-cyclodextrin polymers were measured by isothermal titration calorimetry and fluorescence spectroscopy, showing no binding with β-cyclodextrin but high binding with β-cyclodextrin polymers. In aqueous solution nanoparticles were formed from association between the (S-camptothecin–dextran polymers and the β-cyclodextrin polymers.

  5. Inclusion complex of amiodarone hydrochloride with cyclodextrins: preparation, characterization and dissolution rate evaluation

    Directory of Open Access Journals (Sweden)

    Alexandre Machado Rubim

    2017-06-01

    Full Text Available ABSTRACT This study aimed to improve the water solubility of amiodarone hydrochloride (AMH via inclusion complexes with β-cyclodextrin, methyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin. Inclusion complexes were developed by physical mixture, coevaporation, spray-drying and freeze-drying. Solid state analysis was performed using X-ray powder diffraction, differential scanning calorimetry and scanning electronic microscopy. Thermodynamic studies demonstrate that the inclusion complexes of drug into different cyclodextrins were an exothermic process that occurred spontaneously. Water solubility and drug dissolution rates were significantly increased after the formation of inclusion complexes with the cyclodextrins evaluated in relation to the physical mixture and pure drug. The present study provides useful information for the potential application of complexation with amiodarone HCl. This may be a good strategy for the development of solid pharmaceutical dosage forms.

  6. Characterization of pioglitazone cyclodextrin complexes: Molecular modeling to in vivo evaluation

    Directory of Open Access Journals (Sweden)

    Dinesh M Bramhane

    2016-01-01

    Full Text Available Aims: The objective of present study was to study the influence of different β-cyclodextrin derivatives and different methods of complexation on aqueous solubility and consequent translation in in vivo performance of Pioglitazone (PE. Material and Methods: Three cyclodextrins: β-cyclodextrin (BCD, hydroxypropyl-β-cyclodextrin (HPBCD and Sulfobutylether-7-β-cyclodextrin (SBEBCD were employed in preparation of 1:1 Pioglitazone complexes by three methods viz. co-grinding, kneading and co-evaporation. Complexation was confirmed by phase solubility, proton NMR, Fourier Transform Infrared spectroscopy, Differential Scanning Calorimetry (DSC and X-Ray diffraction (XRD. Mode of complexation was investigated by molecular dynamic studies. Pharmacodynamic study of blood glucose lowering activity of PE complexes was performed in Alloxan induced diabetic rat model. Results: Aqueous solubility of PE was significantly improved in presence of cyclodextrin. Apparent solubility constants were observed to be 254.33 M–1 for BCD-PE, 737.48 M–1 for HPBCD-PE and 5959.06 M–1 for SBEBCD-PE. The in silico predictions of mode of inclusion were in close agreement with the experimental proton NMR observation. DSC and XRD demonstrated complete amorphization of crystalline PE upon inclusion. All complexes exhibited >95% dissolution within 10 min compared to drug powder that showed <40% at the same time. Marked lowering of blood glucose was recorded for all complexes. Conclusion: Complexation of PE with different BCD significantly influenced its aqueous solubility, improved in vitro dissolution and consequently translated into enhanced pharmacodynamic activity in rats

  7. Pyrolysis characteristics and kinetics of β-cyclodextrin and its two derivatives

    Directory of Open Access Journals (Sweden)

    Zhu Guangyong

    2015-12-01

    Full Text Available β-cyclodextrin (β-CD and its derivatives have been widely used to prepare inclusion complexes. However, systematic research on their thermal stabilities, pyrolysis characteristics and kinetics has rarely been reported. In this paper, thermogravimetric analysis was employed to investigate β-cyclodextrin and its two derivatives, 2-Hydroxypropyl-β-cyclodextrin (HP-β-CD and monochlorotriazinyl-β-cyclodextrin (MCT-β-CD. The pyrolysis characteristics and kinetic parameters were obtained. The results show that three stages can be distinguished during the heating process of the above three samples. The temperature of initial decomposition of HP-β-CD (309.5°C is higher than that of β-CD (297.8°C, while the temperature of initial decomposition of MCT-β-CD (231.4°C is lower than that of β-CD. For the three cyclodextrins, the thermal stability in descending order is HP-β-CD, β-CD and MCT-HP-β-CD. The activation energy values are 350.6, 303.3 and 113.9 KJ/mol, and the pre-exponential factor values are 1.11×1031, 1.37×1026 and 1.39×1010 for β-CD, HP-β-CD and MCT-β-CD respectively.

  8. Mucoadhesive Cyclodextrin-Modified Thiolated Poly(aspartic acid as a Potential Ophthalmic Drug Delivery System

    Directory of Open Access Journals (Sweden)

    Mária Budai-Szűcs

    2018-02-01

    Full Text Available Thiolated poly(aspartic acid is known as a good mucoadhesive polymer in aqueous ophthalmic formulations. In this paper, cyclodextrin-modified thiolated poly(aspartic acid was synthesized for the incorporation of prednisolone, a lipophilic ophthalmic drug, in an aqueous in situ gellable mucoadhesive solution. This polymer combines the advantages of cyclodextrins and thiolated polymers. The formation of the cyclodextrin-drug complex in the gels was analyzed by X-ray powder diffraction. The ocular applicability of the polymer was characterized by means of physicochemical, rheological and drug diffusion tests. It was established that the chemical bonding of the cyclodextrin molecule did not affect the complexation of prednisolone, while the polymer solution preserved its in situ gellable and good mucoadhesive characteristics. The chemical immobilization of cyclodextrin modified the diffusion profile of prednisolone and prolonged drug release was observed. The combination of free and immobilized cyclodextrins provided the best release profile because the free complex can diffuse rapidly, while the bonded complex ensures a prolonged action.

  9. Effect of β-cyclodextrin on Rheological Properties of some Viscosity Modifiers.

    Science.gov (United States)

    Rao, G Chandra Sekhara; Ramadevi, K; Sirisha, K

    2014-01-01

    Cyclodextrins are a group of novel excipients, extensively used in the present pharmaceutical industry. Sometimes they show significant interactions with other conventional additives used in the formulation of dosage forms. The effect of β-cyclodextrin on the rheological properties of aqueous solutions of some selected viscosity modifiers was studied in the present work. β-cyclodextrin showed two different types of effects on the rheology of the selected polymers. In case of natural polymers like xanthan gum and guar gum, enhanced apparent viscosity was found and in case of semi-synthetic polymers like sodium carboxymethyl cellulose and methyl cellulose, reduction in apparent viscosity was found. β-cyclodextrin was included at 0.5, 1 and 2% w/v concentrations into the polymeric solutions. These findings are useful in the adjustment of concentrations of viscosity modifiers during the formulation of physically stable disperse systems.

  10. Cyclodextrins as Protective Agents of Protein Aggregation: An Overview.

    Science.gov (United States)

    Oliveri, Valentina; Vecchio, Graziella

    2016-06-06

    Cyclodextrins are extensively used in different fields (e.g., catalysis, chromatography, pharma, supramolecular chemistry, bioorganic chemistry, and bioinorganic chemistry), and their applications have been widely reviewed. Their main application in the field of pharmaceutical is as a drug carrier. This review overviews, for the first time, the use of cyclodextrins and their derivatives as antiaggregant agents in a number of proteins (e.g., amyloid-β, insulin, recombinant human growth hormone, prion protein, transthyretin, and α-synuclein) and some multimeric enzymes. There are many diseases that are correlated to protein misfolding and amyloid formation processes affecting numerous organs and tissues. There are over 30 different amyloid proteins and a number of corresponding diseases. Alzheimer's disease is the most common neurodegenerative disease. Treatment of these diseases is still a goal to reach, and many molecules are studied in this perspective. Cyclodextrins have also been studied, and they show great potential; as such, further studies could be very promising. This review aims to be a stimulus for the design of new cyclodextrin derivatives to obtain multifunctional systems with antiaggregant activity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Dioxin sensing which uses fluorescent cyclodextrin; Keikosei shikurodekisutorin wo mochiita daiokishin senshingu

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, F. [Akita Univ., Akita (Japan)

    2000-05-01

    Environmental hormones are called pluricausal endocrine disrupting chemical substances (endocrine disrupters) that are deemed to disrupt effects of vital hormones and give influence to homeostasis of in vivo environment. Today, 70,000 to 80,000 kinds of chemical substances are used in the world, and about 70 kinds among them are suspected of being environmental hormones. The present authors have clarified that a host with fluorescent residue chemically bonded to cyclodextrin responses at a high sensitivity to bile acids having a steroid skeleton. In this paper, dioxin sensing that uses fluorescent cyclodextrin is described. Florescent sensing of a dansyl group or anthranyl ground modified cyclodextrin having somewhat different molecular sizes; and sensing of hetero-2 substituted-dansyl-tosyl, modified {beta}-, cyclodextrin are examined. (NEDO)

  12. Does the Digestibility of Cyclodextrins Influence the In Vivo Absorption of Benzo[a] pyrene in Rats?

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Vana, Vasiliki; Holm, Rene

    2016-01-01

    -Cyclodextrin is digestible in contrast to b-cyclodextrins. This could potentially limit the sensitivity toward overdose, which was evaluated using benzo[a] pyrene in this study, in which rats were administered benzo[a] pyrene and different doses of the 2 cyclodextrins. Both cyclodextrins lowered the area under the curve......,000 at the concentration where a significant decrease in the absorption was observed. No difference was observed between the 2 cyclodextrins, so digestibility seemed less important. More interesting was that the decrease in absorption was relatively small when compared with literature values, suggesting that the effect...

  13. Biophysical aspects of cyclodextrin interaction with paraoxon.

    Science.gov (United States)

    Soni, Sunil-Datta; Bhonsle, Jayendra B; Garcia, Gregory E

    2014-03-01

    Cyclodextrins are torus-shaped polymers of glucose that can bind organophosphorous compounds such as nerve agents and pesticides. We demonstrate here that cyclodextrin can bind up to two paraoxon molecules with a K(av) of 6775 M(-1). Molecular modeling shows that the paraoxon appears to bind in polar opposite orientation and have an average binding energy of -89 Kcals/mol. Published 2013. This article is a U.S. Government work and is in the public domain in the USA. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  14. Cyclodextrin-functionalized mesostructured silica nanoparticles for removal of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Topuz, Fuat; Uyar, Tamer

    2017-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are the byproducts of the incomplete combustion of carbon-based fuels, and have high affinity towards DNA strands, ultimately exerting their carcinogenic effects. They are ubiquitousenvironmental contaminants,and can accumulate on tissues due to their lipophilic nature. In this article, we describe a novel concept for PAH removal from aqueous solutions using cyclodextrin-functionalized mesostructured silica nanoparticles (CDMSNs) and pristine mesostructured silica nanoparticles (MSNs). The adsorption applications of MSNs are greatly restricted due to the absence of surface functional groups on such particles. In this regard, cyclodextrins can serve as ideal functional molecules with their toroidal, cone-type structure, capable of inclusion-complex formation with many hydrophobic molecules, including genotoxic PAHs. The CDMSNs were synthesized by the surfactant-templated, NaOH-catalyzed condensation reactions of tetraethyl orthosilicate (TEOS) in the presence of two different types of cyclodextrin (i.e. hydroxypropyl-β-cyclodextrin (HP-β-CD) and native β-cyclodextrin (β-CD)). The physical incorporation of CD moieties was supported by XPS, FT-IR, NMR, TGA and solid-state 13 C NMR. The CDMSNs were treated with aqueous solutions of five different PAHs (e.g. pyrene, anthracene, phenanthrene, fluorene and fluoranthene). The functionalization of MSNs with cyclodextrin moieties significantly boosted the sorption capacity (q) of the MSNs up to ∼2-fold, and the q ranged between 0.3 and 1.65mg per gram CDMSNs, of which the performance was comparable to that of the activated carbon. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Intestinal Permeability of β-Lapachone and Its Cyclodextrin Complexes and Physical Mixtures.

    Science.gov (United States)

    Mangas-Sanjuan, Victor; Gutiérrez-Nieto, Jorge; Echezarreta-López, Magdalena; González-Álvarez, Isabel; González-Álvarez, Marta; Casabó, Vicente-Germán; Bermejo, Marival; Landin, Mariana

    2016-12-01

    β-Lapachone (βLAP) is a promising, poorly soluble, antitumoral drug. βLAP combination with cyclodextrins (CDs) improves its solubility and dissolution but there is not enough information about the impact of cyclodextrins on βLAP intestinal permeability. The objectives of this work were to characterize βLAP intestinal permeability and to elucidate cyclodextrins effect on the dissolution properties and on the intestinal permeability. The final goal was to evaluate CDs influence on the oral absorption of βLAP. Binary systems (physical mixtures and inclusion complexes) including βLAP and CDs (β-cyclodextrin: βCD, random-methyl-β-cyclodextrin: RMβCD and sulfobutylether-β-cyclodextrin: SBEβCD) have been prepared and analysed by differential scanning calorimetry. βLAP (and its combinations with CDs) absorption rate coefficients and effective permeability values have been determined in vitro in MDCK or MDCK-Mdr1 monolayers and in situ in rat by a closed loop perfusion technique. DSC results confirmed the formation of the inclusion complexes. βLAP-CDs inclusion complexes improve drug solubility and dissolution rate in comparison with physical mixtures. βLAP presented a high permeability value which can provide complete oral absorption. Its oral absorption is limited by its low solubility and dissolution rate. Cyclodextrin (both as physical mixtures and inclusion complexes) showed a positive effect on the intestinal permeability of βLAP. Complexation with CDs does not reduce βLAP intestinal permeability in spite of the potential negative effect of the reduction in free fraction of the drug. The use of RMβCD or SBEβCD inclusion complexes could benefit βLAP oral absorption by enhancing its solubility, dissolution rate and permeability.

  16. A new potentiometric electrode incorporating functionalized β-cyclodextrins for diclofenac determination.

    Science.gov (United States)

    Lenik, Joanna

    2014-12-01

    This paper reports the preparation of diclofenac-selective membrane electrodes incorporating β-cyclodextrins: (2-hydroxypropyl)-β-cyclodextrin, heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin, and heptakis(2,3,6-tri-O-benzoyl)-β-cyclodextrin. Several plasticized poly(vinyl chloride) membranes of different compositions were tested with the best electrode being the one incorporating heptakis(2,3,6-tri-O-benzoyl)-β-cyclodextrin with the membrane plasticized with 2-nitrophenyloctyl ether. The electrode is characterized by a near-Nernstian response slope of -60.0 mV decade(-1) over the linear range of 5.0×10(-5)-1.0×10(-2) mol L(-1) and a limit of detection of 1.4×10(-5) mol L(-1). The proposed electrode can easily discriminate diclofenac ions from several inorganic and organic interferents and some common drug excipients. The electrode has a response time of 10s and can be used within a pH range of 6.2-8.5 over 10 months without any considerable deterioration. The electrical properties of the membrane electrode were studied by impedance spectroscopy. The notable advantages of the diclofenac-selective electrode include its high sensitivity, selectivity, cost-effectiveness, and comfortable application in drug and urine analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Synthesis and characterization of polyurethanes derived from cyclodextrins and poli (ethyleneglycol)

    International Nuclear Information System (INIS)

    Araujo, Marcia V.G. de; Vieira, Joao V.F.; Zawadzki, Sonia F.

    2011-01-01

    Cyclodextrins are natural cyclic oligosaccharides that have the ability to form inclusion complexes with various chemical species. In this work, the polymers with beta-cyclodextrin (BCD) or hydroxypropyl-beta-cyclodextrin (HPBCD) were synthesized from the reaction with poly (ethylene) glycol (PEG400, PEG1500, PEG4000) and diisocyanate, toluene 2,4 and 3,6 (TDI) in a solution of dimethylformamide (DMF). The polymers were characterized by infrared Fourier transform spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The encapsulation capacity was evaluated by calorimetric method of discoloration of the alkaline solution of phenolphthalein. FTIR analysis revealed that assignments confirmed the formation of urethane linkages. TGA was evidenced by the mass loss in three stages and the evaluation results by XRD showed a crosslinking process. The evaluation of the encapsulation capacity of the units of the cyclodextrin crosslinked polymer showed that encapsulation increased proportionally to the mass of polymer used. (author)

  18. Effect of methyl-β-cyclodextrin on gene expression in microbial conversion of phytosterol.

    Science.gov (United States)

    Shtratnikova, Victoria Y; Schelkunov, Mikhail I; Dovbnya, Dmitry V; Bragin, Eugeny Y; Donova, Marina V

    2017-06-01

    Modified β-cyclodextrins are widely used for the enhancement of microbial conversions of lipophilic compounds such as steroids. Multiple mechanisms of cyclodextrin-mediated enhancement of phytosterol bioconversion by mycobacteria had previously been shown to include steroid solubilization, alterations in the cell wall permeability for both steroids and nutrients, facilitation of protein leaking, and activity suppression of some steroid-transforming enzymes.In this work, we studied whether cyclodextrins might affect expression of the genes involved in the steroid catabolic pathway. Phytosterol bioconversion with 9α-hydroxy-androst-4-ene-3,17-dione accumulation by Mycobacterium sp. VKM Ac-1817D in the presence of methylated β-cyclodextrin (MCD) was investigated. RNA sequencing of the whole transcriptomes in different combinations of phytosterol and MCD showed a similar expression level of the steroid catabolism genes related to the KstR-regulon and was responsible for side chain and initial steps of steroid core oxidation; whereas, induction levels of the genes related to the KstR2-regulon were attenuated in the presence of MCD in this strain. The data were attenuated with quantitative real-time PCR.The results contribute to the understanding of cyclodextrin effects on microbial steroid conversion and provide a basis for the use of cyclodextrins as expression enhancers for studies of sterol catabolism in actinobacteria.

  19. Iodine K-edge EXAFS analysis of iodide ion-cyclodextrin inclusion complexes in aqueous solution

    International Nuclear Information System (INIS)

    Kaneko, T; Ueda, M; Nagamatsu, S; Konishi, T; Fujikawa, T; Mizumaki, M

    2009-01-01

    We study the structure of inclusion complexes of α-, β-, γ-cyclodextrin with mono-iodide ion in aqueous solution by means of iodine K-edge EXAFS spectroscopy. The analysis is based on the assumption that two kinds of iodide ions exist in KI-cyclodextrin aqueous solution i.e. hydrated mono-iodide ions and one-one mono-iodide-cyclodextrin inclusion complexes. In KI-α-cyclodextrin system, iodine K-edge EXAFS analyse show that the average coordination number of the oxygen atoms in water molecules in the first hydration shell decreases as the fraction of included ions increases. This result suggests that dehydration process accompanies the formation of the inclusion complex. This is not found in the case of β-cyclodextrin, indicating that in this case the iodide ions are included together with the whole first hydration shell.

  20. Transfer action of cyclodextrin glycosyltransferase on starch

    Energy Technology Data Exchange (ETDEWEB)

    Kitahata, S; Okada, S [Osaka City Technical Research Inst. (Japan)

    1975-11-01

    The transglycosylation reaction of the cyclodextrin glycosyltransferase from Bacillus megaterium (No. 5 enzyme) and Bacillus macerans (BMA) were examined. No.5 enzyme was more efficient in transglycosylation reaction than BMA in the every acceptor employed in the present study. The order of the efficient acceptors for No. 5 enzyme was maltose (G2), glucose (G1), maltotriose (G3) and sucrose (GF). On the other hand, that found for BMA was G1, G2, GF and G3. The transglycosylation products to glucose formed by the action of No. 5 enzyme on starch were G2, G3, maltotetraose (G4), maltopentaose (G5), maltohexaose (G6) and maltoheptaose (G7) in the order of their quantities, while, in the case of BMA, they were G2, G3, G5, G7 = G4 and G6. The larger transglycosylation products to sucrose formed by the action of No. 5 enzyme on starch were maltosylfructose. On the other hand, that formed by the action of BMA was maltoheptaosylfructose. It was suggested that cyclodextrin glycosyltransferase could transfer the glucosyl residues to an acceptor directly from starch, as well as through cyclodextrin.

  1. Synergistic radical scavenging potency of curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes

    Energy Technology Data Exchange (ETDEWEB)

    Aadinath, W.; Bhushani, Anu; Anandharamakrishnan, C., E-mail: anandhram@cftri.res.in

    2016-07-01

    Curcumin is a highly potent nutraceutical associated with various health benefits. However, its hydrophobic nature affects its bioavailability and bioactivity, and limits nutraceutical applications. Drug-in-cyclodextrin-in-liposome has the ability to mask the hydrophobic nature of drug and achieve better encapsulation. Also, encapsulating iron oxide nanoparticles (IONPs) within liposomes endow additional beneficial functionalities of IONPs. In the present study, curcumin-β-cyclodextrin inclusion complex (IC) and IONPs were co-encapsulated within liposomes (curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes) to achieve the synergistic antioxidant potential of curcumin and IONPs. IC of curcumin-β-cyclodextrin was prepared by a simple rapid method and successful inclusion was confirmed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Mean diameter of IONPs was found to be 180 nm and X-ray diffraction pattern confirmed the formation of hematite nanoparticles. Band gap energy calculated using absorption spectra was 2.25 eV, which falls in close proximity with the theoretically calculated values of hematite. Mean diameter of curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes was 67 nm and encapsulation efficiency of curcumin was found to be 71%. Further, the co-encapsulated particles possessed significantly low IC{sub 50} value (64.7791 μg/ml, p < 0.01) compared to conventional curcumin liposome and IONPs, indicating its synergistically enhanced radical scavenging property. - Highlights: • Curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes (mean diameter, 67 nm) has been prepared. • Encapsulation efficiency of curcumin was found to be 71%. • IONPs in the nano-carrier play dual role of targeted delivery and radical scavenging activities. • Conjunction of IONPs and curcumin into the liposomes increases the radical scavenging activity.

  2. Removal of polycyclic aromatic hydrocarbons from aged-contaminated soil using cyclodextrins: Experimental study

    International Nuclear Information System (INIS)

    Viglianti, Christophe; Hanna, Khalil; Brauer, Christine de; Germain, Patrick

    2006-01-01

    The removal of polycyclic aromatic hydrocarbons (PAHs) from soil using water as flushing agent is relatively ineffective due to their low aqueous solubility. However, addition of cyclodextrin (CD) in washing solutions has been shown to increase the removal efficiency several times. Herein are investigated the effectiveness of cyclodextrin to remove PAH occurring in industrially aged-contaminated soil. β-Cyclodextrin (BCD), hydroxypropyl-β-cyclodextrin (HPCD) and methyl-β-cyclodextrin (MCD) solutions were used for soil flushing in column test to evaluate some influent parameters that can significantly increase the removal efficiency. The process parameters chosen were CD concentration, ratio of washing solution volume to soil weight, and temperature of washing solution. These parameters were found to have a significant and almost linear effect on PAH removal from the contaminated soil, except the temperature where no significant enhancement in PAH extraction was observed for temperature range from 5 to 35 o C. The PAHs extraction enhancement factor compared to water was about 200. - An innovative method using a biodegradable and non-toxic flushing agent for the depollution of industrially aged-contaminated soil

  3. A heuristic model to quantify the impact of excess cyclodextrin on oral drug absorption from aqueous solution

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Westh, Peter; Holm, René

    2016-01-01

    , the cyclodextrin concentration in the drug product must be higher than the amount needed to solubilise the compound, due to the displacement of the drug from the cyclodextrin cavity by bile salts in the intestinal lumen. On the other hand, dosing cyclodextrin at View the MathML source>DtotSC is expected to result...... the implication of having excess cyclodextrin in an oral solution....

  4. Enthalpy of solution of α- and β-cyclodextrin in water and in some organic solvents

    International Nuclear Information System (INIS)

    Belica, Sylwia; Sadowska, Monika; Stępniak, Artur; Graca, Anna; Pałecz, Bartłomiej

    2014-01-01

    Highlights: • A great influence of crystalline water on the energetic of dissolving compounds. • The strongest interaction between β-cyclodextrin and DMSO. • The enthalpic pair interaction coefficient, h βCD-EtOH , obtained is positive. • Predominating effects of the partial dehydration of the molecules – βCD-EtOH. -- Abstract: The calorimetric measurements of solution enthalpy of α-cyclodextrin, β-cyclodextrin in water (H 2 O), dimetyloformamid (DMF), dimethyl sulfoxide (DMSO) and aqueous ethanol solutions (H 2 O + EtOH) at 298.15 K were made. The experimental results were used to calculate the enthalpic coefficients of the interactions between cyclodextrin and ethanol molecules in water based on McMillan–Mayer’s model. The results were compared with literature data and with hydrodynamic radii of cyclodextrin in examined solvents and with donor numbers of these solvents. In order to check, if the inclusion complex formation between the solvent with the highest enthalpy of solution and cyclodextrin has happened, the calorimetric isothermal titration measurements were made and the results were interpreted

  5. Free radical homopolymerization of a vinylferrocene/cyclodextrin complex in water

    Directory of Open Access Journals (Sweden)

    Helmut Ritter

    2010-06-01

    Full Text Available We report the radical initiated homopolymerization of a soluble vinylferrocene cyclodextrin-complex in water. Uncomplexed vinylferrocene 1 and the corresponding homopolymer are hydrophobic and completely insoluble in water. Complexation of 1 with methyl-β-cyclodextrin 2 results in clearly water-soluble structures due to incorporation of the ferrocene moiety into the cyclodextrin cavity. After free radical polymerization of the water-soluble complexed monomer, corresponding to polyvinylferrocene (PVFc, the water-soluble polymer is obtained due to the host guest interactions. Those polymeric complexes are stable in water up to about 90 °C. Above this temperature the polymer precipitates due to decomplexation. The complex was investigated by 1H NMR spectrometry, dynamic light scattering (DLS, differential scanning calorimetry (DSC, and lower critical solution temperature (LCST measurements.

  6. Modulating Pluronics micellar rupture with cyclodextrins and drugs: effect of pH and temperature

    International Nuclear Information System (INIS)

    Valero, M; Dreiss, C A

    2014-01-01

    Micelles of the triblock copolymer Pluronic F127 can encapsulate drugs with various chemical structures and their architecture has been studied by small-angle neutron scattering (SANS). Interaction with a derivative of β-cyclodextrin, namely, heptakis(2,6-di-O- methyl)-β-cyclodextrin (DIMEB), induces a complete break-up of the micelles, providing a mechanism for drug release. In the presence of drugs partitioned within the micelles, competitive interactions between polymer, drug and cyclodextrin lead to a modulation of the micellar rupture, depending on the nature of the drug and the exact composition of the ternary system. These interactions can be further adjusted by temperature and pH. While the most widely accepted mechanism for the interaction between Pluronics and cyclodextrins is through polypseudorotaxane (PR) formation, involving the threading of β-CD on the polymer backbone, time-resolved SANS experiments show that de-micellisation takes place in less than 100 ms, thus unambiguously ruling out an inclusion complex between the cyclodextrin and the polymer chains

  7. Promising applications in drug delivery systems of a novel β-cyclodextrin derivative obtained by green synthesis.

    Science.gov (United States)

    García, Agustina; Leonardi, Darío; Lamas, María C

    2016-01-15

    An efficient and green method has been developed for the synthesis of succinyl-β-cyclodextrin in aqueous media obtaining very good yield. Acidic groups have been introduced in the synthesized carrier molecule to improve the guest-host affinity. To evaluate the suitability of the novel excipient focused to develop oral dosage forms, albendazole, a BSC class II compound, was chosen as a model drug. The β-cyclodextrin derivative and the inclusion complex were thoroughly characterized in solution and solid state by phase solubility studies, FT-IR spectroscopy, SEM, XRD, ESI-MS, DSC, 1D (1)H NMR, 1D (13)C NMR, selective 1D TOCSY, 2D COSY, 2D HSQC, 2D HMBC and ROESY NMR spectroscopy. Phase solubility studies indicated that both of them β-cyclodextrin and succinyl-β-cyclodextrin formed 1:1 inclusion complexes with albendazole, and the stability constants were 68M(-1) (β-cyclodextrin), 437M(-1) (succinyl-β-cyclodextrin), respectively. Water solubility and dissolution rate of albendazole were significantly improved in complex forms. Thus, the succinyl-β-cyclodextrin derivative could be a promising excipient to design oral dosage forms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Studies on the Inclusion Complexes of Daidzein with β-Cyclodextrin and Derivatives

    Directory of Open Access Journals (Sweden)

    Shujing Li

    2017-12-01

    Full Text Available The inclusion complexes between daidzein and three cyclodextrins (CDs, namely β-cyclodextrin (β-CD, methyl-β-cyclodextrin (Me-β-CD, DS = 12.5 and (2-hydroxypropyl-β-cyclodextrin (HP-β-CD, DS = 4.2 were prepared. The effects of the inclusion behavior of daidzein with three kinds of cyclodextrins were investigated in both solution and solid state by methods of phase-solubility, XRD, DSC, SEM, 1H-NMR and 2D ROESY methods. Furthermore, the antioxidant activities of daidzein and daidzein-CDs inclusion complexes were determined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH method. The results showed that daidzein formed a 1:1 stoichiometric inclusion complex with β-CD, Me-β-CD and HP-β-CD. The results also showed that the solubility of daidzein was improved after encapsulating by CDs. 1H-NMR and 2D ROESY analyses show that the B ring of daidzein was the part of the molecule that was most likely inserted into the cavity of CDs, thus forming an inclusion complex. Antioxidant activity studies showed that the antioxidant performance of the inclusion complexes was enhanced in comparison to the native daidzein. It could be a potentially promising way to develop a new formulation of daidzein for herbal medicine or healthcare products.

  9. Determination of binding constants of cyclodextrin inclusion complexes with amino acids and dipeptides by potentiometric titration.

    Science.gov (United States)

    Kahle, Claudia; Holzgrabe, Ulrike

    2004-10-01

    Cyclodextrins are well known for their ability to separate enantiomers of drugs, natural products, and other chiral substances using HPLC, GC, or CE. The resolution of the enantiomers is due to the formation of diastereomeric complexes between the cyclodextrin and the pairs of enantiomers. The aim of this study was to determine the binding constants of the complexes between alpha- and beta-cyclodextrin and the enantiomers of a series of aliphatic and aromatic amino acids, and dipeptides, using a potentiometric titration method. The results of this method are compared to other methods, and correlated to findings in cyclodextrin-modified capillary electrophoresis and possible complex structures. Potentiometric titration was found to be an appropriate tool to determine the binding constants of cyclodextrin inclusion complexes.

  10. A new purity criterion for α- and β-cyclodextrin using partition chromatography on cellulose columns

    NARCIS (Netherlands)

    Lammers, J.N.J.J.

    1967-01-01

    In order to check the purity of a- and b-cyclodextrins with respect to each other partition chromatog. on cellulose columns was used (elution with 42:29:29 BuOH-EtOH-H2O, 0.3 atm. air pressure on the solvent reservoir; 75-90 ml./hr. flow rate). Amts. down to 2.5% a-cyclodextrin (I) in b-cyclodextrin

  11. Potential of activated carbon to recover randomly-methylated-β-cyclodextrin solution from washing water originating from in situ soil flushing.

    Science.gov (United States)

    Sniegowski, K; Vanhecke, M; D'Huys, P-J; Braeken, L

    2014-07-01

    Despite the overall high efficacy of cyclodextrins to accelerate the treatment of soil aquifer remediation by in-situ soil flushing, the use in practice remains limited because of the high costs of cyclodextrin and high concentrations needed to significantly reduce the treatment time. The current study tested the potential of activated carbon to treat washing water originating from soil flushing in order to selectively separate hydrocarbon contaminants from washing water containing cyclodextrin and subsequently reuse the cyclodextrin solution for reinfiltration. A high recovery of the cyclodextrin from the washing water would reduce the costs and would make the technique economically feasible for soil remediation. This study aimed to investigate whether cyclodextrin can pass through the activated carbon filter without reducing the cyclodextrin concentration when the contaminated washing water is treated and whether the presence of cyclodextrin negatively affects the purification potential of activated carbon to remove the organic pollutants from the pumped soil water. Lab-scale column experiments showed that with the appropriate activated carbon 100% of cyclodextrin (randomly-methylated-β-cyclodextrin) can be recovered from the washing water and that the effect on the efficiency of activated carbon to remove the hydrocarbon contaminants remains limited. These results show that additional field tests are useful to make in-situ soil flushing with cyclodextrin both a technical and an economical interesting technique. These results might stimulate the application of cyclodextrin in soil treatment technology. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. An MM and QM Study of Biomimetic Catalysis of Diels-Alder Reactions Using Cyclodextrins

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2018-01-01

    Full Text Available We performed a computational investigation of the mechanism by which cyclodextrins (CDs catalyze Diels-Alder reactions between 9-anthracenemethanol and N-cyclohexylmaleimide. Hydrogen bonds (Hbonds between N-cyclohexylmaleimide and the hydroxyl groups of cyclodextrins were suggested to play an important role in this catalytic process. However, our free energy calculations and molecular dynamics simulations showed that these Hbonds are not stable, and quantum mechanical calculations suggested that the reaction is not promoted by these Hbonds. The binding of 9-anthracenemethanol and N-cyclohexylmaleimide to cyclodextrins was the key to the catalytic process. Cyclodextrins act as a container to hold the two reactants in the cavity, pre-organize them for the reactions, and thus reduce the entropy penalty to the activation free energy. Dimethyl-β-CD was a better catalyst for this specific reaction than β-CD because of its stronger van der Waals interaction with the pre-organized reactants and its better performance in reducing the activation energy. This computational work sheds light on the mechanism of the catalytic reaction by cyclodextrins and introduces new perspectives of supramolecular catalysis.

  13. α-Cyclodextrin – Water binary system. New data on dehydration of α-cyclodextrin hexahydrate

    International Nuclear Information System (INIS)

    Manakov, Andrey Yu.; Rodionova, Tatyana V.; Aladko, Lyudmila S.; Villevald, Galina V.; Lipkowski, Janusz S.; Zelenina, Lyudmila N.; Chusova, Tamara P.; Karpova, Tamara D.

    2016-01-01

    Highlights: • The T, x– phase diagram of α-CD – water binary system was studied by DTA and DSC. • PXRD was used to follow structural transformation of α-CD hydrates. • α-CD·6.1H 2 O transforms into α-CD·5.3H 2 O at the temperature ∼355 K in isochoric conditions. • The solid solution on the base of α-CD·6H 2 O Form I is formed within the limits of α-CD·6.1H 2 O – α-CD·2.1H 2 O. - Abstract: Cyclodextrins (CDs) are torous-like macrocycles composed of glucopyranose units. Due to their shapes, they are capable to include a wide variety of organic and inorganic guest molecules with formation of inclusion complexes in solid and liquid state. CDs crystallize from aqueous solution as hydrates (water molecules are located in the cavities and fill intermolecular space). The process of inclusion complex formation is, in fact, a replacement reaction of water molecules by hydrophobic guest molecules. Given the important role of water in the formation of CDs inclusion complexes, and the fact that the main commercial forms of cyclodextrins are the hydrated ones, the study of temperature (T) – composition (x) phase diagram of cyclodextrin – water binary system is of scientific and practical interest. This article reports an experimental study of the T, x – phase diagram of α-cyclodextrin – water binary system under isochoric conditions by differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Powder X-ray diffraction was used to identify the structures of different α-CD hydrates and to follow their phase transformations. It was shown that dehydration processes in isochoric and isobaric (open air) conditions differ significantly. In the temperature range of approximately 351 K–359 K the α-CD hexahydrate of known Form I structure transforms into the α-CD·5.3H 2 O of unknown structural type. It is found that the solid solution on the base of the structure α-CD hexahydrate Form I is formed within the limits of

  14. Synthesis and Utilization of Trialkylammonium-Substituted Cyclodextrins as Water-Soluble Chiral NMR Solvating Agents for Anionic Compounds.

    Science.gov (United States)

    Dowey, Alison E; Puentes, Cira Mollings; Carey-Hatch, Mira; Sandridge, Keyana L; Krishna, Nikhil B; Wenzel, Thomas J

    2016-04-01

    Cationic trialkylammonium-substituted α-, β-, and γ-cyclodextrins containing trimethyl-, triethyl-, and tri-n-propylammonium substituent groups were synthesized and analyzed for utility as water-soluble chiral nuclear magnetic resonance (NMR) solvating agents. Racemic and enantiomerically pure (3-chloro-2-hydroxypropyl)trimethyl-, triethyl-, and tri-n-propyl ammonium chloride were synthesized from the corresponding trialkyl amine hydrochloride and either racemic or enantiomerically pure epichlorohydrin. The ammonium salts were then reacted with α-, β-, and γ-cyclodextrins at basic pH to provide the corresponding randomly substituted cationic cyclodextrins. The (1) H NMR spectra of a range of anionic, aromatic compounds was recorded with the cationic cyclodextrins. Cyclodextrins with a single stereochemistry at the hydroxy group on the (2-hydroxypropyl)trialkylammonium chloride substituent were often but not always more effective than the corresponding cyclodextrin in which the C-2 position was racemic. In several cases, the larger triethyl or tri-n-propyl derivatives were more effective than the corresponding trimethyl derivative at causing enantiomeric differentiation. None of the cyclodextrin derivatives were consistently the most effective for all of the anionic compounds studied. © 2016 Wiley Periodicals, Inc.

  15. Evaluation of the potential toxicity of unmodified and modified cyclodextrins on murine blood-brain barrier endothelial cells.

    Science.gov (United States)

    Shityakov, Sergey; Salmas, Ramin Ekhteiari; Salvador, Ellaine; Roewer, Norbert; Broscheit, Jens; Förster, Carola

    2016-04-01

    In this study, we investigated the cytotoxic effects of unmodified α-cyclodextrin (α-CD) and modified cyclodextrins, including trimethyl-β-cyclodextrin (TRIMEB) and hydroxypropyl-β-cyclodextrin (HPβCD), on immortalized murine microvascular endothelial (cEND) cells of the blood-brain barrier (BBB). A CellTiter-Glo viability test, performed on the cEND cells showed significant differences among the different cyclodextrins. After 24 hr of incubation, TRIMEB was the most cytotoxic, and HPβCD was non-toxic. α-CD and TRIMEB exhibited greater cytotoxicity in the Dulbecco's modified Eagle's medium than in heat-inactivated human serum indicating protective properties of the human serum. The predicted dynamic toxicity profiles (Td) for α-CD and TRIMEB indicated higher cytotoxicity for these cyclodextrins compared to the reference compound (dimethylsulfoxide). Molecular dynamics simulation of cholesterol binding to the CDs suggested that not just cholesterol but phospholipids extraction might be involved in the cytotoxicity. Overall, the results demonstrate that HPβCD has the potential to be used as a candidate for drug delivery vector development and signify a correlation between the in vitro cytotoxic effect and cholesterol binding of cyclodextrins.

  16. NMR Investigation of the complexation of (S-2-isopropyl- 1-(o-nitrophenylsulfonylaziridine with -cyclodextrin

    Directory of Open Access Journals (Sweden)

    Mohamed Z. Sliman

    2014-07-01

    Full Text Available Aziridines are known to undergo hydrolysis in the presence of cyclodextrins, whereas the latter are largely investigated as potential vectors of biologically active compounds. Despite this easy cyclodextrin-induced cleavage of aziridines in aqueous medium, it was of interest to find out a model aziridine derivative that would be sufficiently water-stable and form a stable complex with b-cyclodextrin in aqueous medium, so that it could be used as a reference in future formulations or vectorization work. Among compounds we have investigated, we found out that only (S-2-isopropyl-1-(o-nitrophenylsulfonylaziridine complied with the above-mentioned solubility and stability requirements. NMR studies of the inclusion complex of this derivative with b-cyclodextrin provided useful parameters related to the stoichiometry of the complex and the association constant Ka. The geometry of the complex was assessed by 2D-ROESY experiments, suggesting a deep insertion of the aziridine into the cavity of b-cyclodextrin.

  17. Self-Assembled Monolayers on Gold of β-Cyclodextrin Adsorbates with Different Anchoring Groups

    NARCIS (Netherlands)

    Méndez Ardoy, Alejandro; Steentjes, Tom; Kudernac, Tibor; Huskens, Jurriaan

    2014-01-01

    We designed multivalent β-cyclodextrin-based adsorbates bearing different anchoring groups aiming to yield stable monolayers with improved packing and close contact of the cavity to the gold surface. Toward this end the primary rim of the β-cyclodextrin was decorated with several functional groups,

  18. Determination of the glass transition temperature of cyclodextrin polymers.

    Science.gov (United States)

    Tabary, Nicolas; Garcia-Fernandez, Maria Jose; Danède, Florence; Descamps, Marc; Martel, Bernard; Willart, Jean-François

    2016-09-05

    The aim of this work was to determine the main physical characteristics of β-cyclodextrin polymers, well known for improving complexation capacities and providing enhanced and sustained release of a large panel of drugs. Two polymers were investigated: a polymer of β-cyclodextrin (polyβ-CD) and a polymer of partially methylated (DS=0.57) β-cyclodextrin (polyMe-β-CD). The physical characterizations were performed by powder X-ray diffraction and differential scanning calorimetry. The results indicate that these polymers are amorphous and that their glass transition is located above the thermal degradation point of the materials preventing their direct observation and thus their full characterization. We could however estimate the virtual glass transition temperatures by mixing the polymers with different plasticizers (trehalose and mannitol) which decreases Tg sufficiently to make the glass transition observable. Extrapolation to zero plasticizer concentration then yield the following Tg values: Tg (polyMe-β-CD)=317°C±5°C and Tg (polyβ-CD)=418°C±6°C. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Removal of emerging micropollutants from water using cyclodextrin.

    Science.gov (United States)

    Nagy, Zsuzsanna Magdolna; Molnár, Mónika; Fekete-Kertész, Ildikó; Molnár-Perl, Ibolya; Fenyvesi, Éva; Gruiz, Katalin

    2014-07-01

    Small scale laboratory experiment series were performed to study the suitability of a cyclodextrin-based sorbent (ß-cyclodextrin bead polymer, BCDP) for modelling the removal of micropollutants from drinking water and purified waste water using simulated inflow test solutions containing target analytes (ibuprofen, naproxen, ketoprofen, bisphenol-A, diclofenac, β-estradiol, ethinylestradiol, estriol, cholesterol at 2-6 μg/L level). This work was focused on the preliminary evaluation of BCDP as a sorbent in two different model systems (filtration and fluidization) applied for risk reduction of emerging micropollutants. For comparison different filter systems combined with various sorbents (commercial filter and activated carbon) were applied and evaluated in the filtration experiment series. The spiked test solution (inflow) and the treated outflows were characterized by an integrated methodology including chemical analytical methods gas chromatography-tandem mass spectrometry (GC-MS/MS) and various environmental toxicity tests to determine the efficiency and selectivity of the applied sorbents. Under experimental conditions the cyclodextrin-based filters used for purification of drinking water in most cases were able to absorb more than 90% of the bisphenol-A and of the estrogenic compounds. Both the analytical chemistry and toxicity results showed efficient elimination of these pollutants. Especially the toxicity of the filtrate decreased considerably. Laboratory experiment modelling post-purification of waste water was also performed applying fluidization technology by ß-cyclodextrin bead polymer. The BCDP removed efficiently from the spiked test solution most of the micropollutants, especially the bisphenol-A (94%) and the hormones (87-99%) The results confirmed that the BCDP-containing sorbents provide a good solution to water quality problems and they are able to decrease the load and risk posed by micropollutants to the water systems. Copyright © 2014

  20. Disintegrating Tablets Using β-Cyclodextrin and Superdisintegrants

    African Journals Online (AJOL)

    RST) using β- cyclodextrin (CD) and different superdisintegrants to enhance their solubility. Methods: A total of 15 FDT formulations of RST were prepared using three different techniques. The FDTs were evaluated for micromeritic properties, ...

  1. Cyclodextrin ketones as oxidation catalysts: investigation of bridged derivatives

    DEFF Research Database (Denmark)

    Fenger, Thomas Hauch; Marinescu, Lavinia; Bols, Mikael

    2009-01-01

    A series of alpha-cyclodextrin derivatives containing a 3, 4 or 5 membered ether-linked bridge between the 6A and 6D oxygen atoms, with and without a ketone, were prepared. The synthesis used perbenzylated alpha-cyclodextrin A,D-diol as a starting material upon which O-alkylation and further modi...... derivatives were also made. The 6A,6D-di-O-(propa-2-on-1,3-diyl)-6C,6F-di-O-methyl and di-O-pivaloyl derivatives were also prepared. The new compounds were analysed for catalysis of the oxidation of amines and alcohols....

  2. Thermodynamics of the interaction of γ-cyclodextrin and tauro- and glyco-conjugated bile salts

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Holm, René

    2013-01-01

    The structural differences in the interaction between natural γ-cyclodextrin and bile salts common in rat, dog and man was were investigated by 1H-ROESY and 13C NMR and molecular modeling and the thermodynamic parameters of the reaction by isothermal titration calorimetry. The γ-cyclodextrin was ......The structural differences in the interaction between natural γ-cyclodextrin and bile salts common in rat, dog and man was were investigated by 1H-ROESY and 13C NMR and molecular modeling and the thermodynamic parameters of the reaction by isothermal titration calorimetry. The γ...

  3. Mesoporous silicas with covalently immobilized β-cyclodextrin moieties: synthesis, structure, and sorption properties

    Science.gov (United States)

    Roik, Nadiia V.; Belyakova, Lyudmila A.; Trofymchuk, Iryna M.; Dziazko, Marina O.; Oranska, Olena I.

    2017-09-01

    Mesoporous silicas with chemically attached macrocyclic moieties were successfully prepared by sol-gel condensation of tetraethyl orthosilicate and β-cyclodextrin-silane in the presence of a structure-directing agent. Introduction of β-cyclodextrin groups into the silica framework was confirmed by the results of IR spectral, thermogravimetric, and quantitative chemical analysis of surface compounds. The porous structure of the obtained materials was characterized by nitrogen adsorption-desorption measurements, powder X-ray diffraction, transmission electron microscopy, and dynamic light scattering. It was found that the composition of the reaction mixture used in β-cyclodextrin-silane synthesis significantly affects the structural parameters of the resulting silicas. The increase in (3-aminopropyl)triethoxysilane as well as the coupling agent content in relation to β-cyclodextrin leads ultimately to the lowering or complete loss of hexagonal arrangement of pore channels in the synthesized materials. Formation of hexagonally ordered mesoporous structure was observed at molar composition of the mixture 0.049 TEOS:0.001 β-CD-silane:0.007 CTMAB:0.27 NH4OH:7.2 H2O and equimolar ratio of components in β-CD-silane synthesis. The sorption of alizarin yellow on starting silica and synthesized materials with chemically attached β-cyclodextrin moieties was studied in phosphate buffer solutions with pH 7.0. Experimental results of the dye equilibrium sorption were analyzed using Langmuir, Freundlich, and Redlich-Peterson isotherm models. It was proved that the Redlich-Peterson isotherm model is the most appropriate for fitting the equilibrium sorption of alizarin yellow on parent silica with hexagonally arranged mesoporous structure as well as on modified one with chemically immobilized β-cyclodextrin groups. [Figure not available: see fulltext.

  4. Evaluation of hydroxypropyl-b-cyclodextrin in the treatment of aldicarb poisoning in rats : short communication

    Directory of Open Access Journals (Sweden)

    R.S. Verster

    2004-06-01

    Full Text Available Cyclodextrins are ring-shaped oligosaccharides with a hydrophilic exterior and a hydrophobic interior. The interior cavity is capable of complexing fat-soluble molecules small enough to fit inside. Sprague-Dawley rats were used to evaluate the efficacy of hydroxypropyl-b-cyclodextrin as treatment of aldicarb poisoning in rats. Survival times in the majority of rats dosed with aldicarb and receiving intravenous cyclodextrin were longer compared with the control rats only dosed with aldicarb per os.

  5. Cyclodextrin Films with Fast Solvent Transport and Shape-Selective Permeability

    KAUST Repository

    Villalobos, Luis Francisco

    2017-04-24

    This study describes the molecular-level design of a new type of filtration membrane made of crosslinked cyclodextrins-inexpensive macrocycles of glucose, shaped like hollow truncated cones. The channel-like cavities of cyclodextrins spawn numerous paths of defined aperture in the separation layer that can effectively discriminate between molecules. The transport of molecules through these membranes is highly shape-sensitive. In addition, the presence of hydrophobic (cavity) and hydrophilic (ester-crosslinked outer part) domains in these films results in high permeances for both polar and nonpolar solvents.

  6. In silico properties characterization of water-soluble γ-cyclodextrin bi-capped C60 complex

    DEFF Research Database (Denmark)

    Cao, Ruyin; Wu, Shanshan

    2015-01-01

    Cyclodextrin-related host-guest encapsulation is pivotal to modulate the solubility of C60, thereby promoting its potential therapeutic applications. Here we present a computational study on γ-cyclodextrin bi-capped C60 complex, probing characteristics for all the possible stoichiometry in aqueou...

  7. Unusual Starch Degradation Pathway via Cyclodextrins in the Hyperthermophilic Sulfate-Reducing Archaeon Archaeoglobus fulgidus Strain 7324▿

    Science.gov (United States)

    Labes, Antje; Schönheit, Peter

    2007-01-01

    The hyperthermophilic archaeon Archaeoglobus fulgidus strain 7324 has been shown to grow on starch and sulfate and thus represents the first sulfate reducer able to degrade polymeric sugars. The enzymes involved in starch degradation to glucose 6-phosphate were studied. In extracts of starch-grown cells the activities of the classical starch degradation enzymes, α-amylase and amylopullulanase, could not be detected. Instead, evidence is presented here that A. fulgidus utilizes an unusual pathway of starch degradation involving cyclodextrins as intermediates. The pathway comprises the combined action of an extracellular cyclodextrin glucanotransferase (CGTase) converting starch to cyclodextrins and the intracellular conversion of cyclodextrins to glucose 6-phosphate via cyclodextrinase (CDase), maltodextrin phosphorylase (Mal-P), and phosphoglucomutase (PGM). These enzymes, which are all induced after growth on starch, were characterized. CGTase catalyzed the conversion of starch to mainly β-cyclodextrin. The gene encoding CGTase was cloned and sequenced and showed highest similarity to a glucanotransferase from Thermococcus litoralis. After transport of the cyclodextrins into the cell by a transport system to be defined, these molecules are linearized via a CDase, catalyzing exclusively the ring opening of the cyclodextrins to the respective maltooligodextrins. These are degraded by a Mal-P to glucose 1-phosphate. Finally, PGM catalyzes the conversion of glucose 1-phosphate to glucose 6-phosphate, which is further degraded to pyruvate via the modified Embden-Meyerhof pathway. PMID:17921308

  8. The effects of cyclodextrins on the disposition of intravenously injected drugs in the rat

    NARCIS (Netherlands)

    Frijlink, H W; Franssen, E J; Eissens, Anko; Oosting, Roelof; Lerk, C F; Meijer, D K

    Naproxen and flurbiprofen form complexes with hydroxypropyl-beta-cyclodextrin; with stability constants of 2207 and 12515 M-1, respectively. However, only small fractions of the drug remain complexed when the drug-cyclodextrin complex is added to plasma in vitro. This result can be explained by

  9. Study on vitamin K 3-cyclodextrin inclusion complex and analytical application

    Science.gov (United States)

    Zhenming, Dong; Xiuping, Liu; Guomei, Zhang; Shaomin, Shuang; Jinghao, Pan

    2003-07-01

    The inclusion interaction of the complexes between Vitamin K3 (VK3) and β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) and sulfobutylether-β-cyclodextrin (SBE-β-CD) were studied by using steady-state fluorescence measurements. The various factors affecting the inclusion process were examined in detail. The formation constants and inclusion stoichiometry for VK3-CDs were determined. The results showed that the inclusion ability of β-CD and its derivatives was the order: SBE-β-CD>HP-β-CD>β-CD. The related inclusion mechanism is proposed to explain the inclusion process. A method of determining VK3 was established with the linear range was 2.5×10-6-5.0×10-4 M, and was used to determine the VK3 tablets. The recoveries were in the range of 97.52-103.5%. The results were satisfactory.

  10. Inclusion complexation of tetrabutylammonium iodide by cyclodextrins

    Indian Academy of Sciences (India)

    Biswajit Datta

    Host-guest inclusion complex of an ionic solid (tetrabutyl ammonium iodide) with α- and β- cyclodextrin has been ... tions.2 CDs are cyclic oligomer of α-D-glucose having numerous of ... of locating at the interface of two phases (liquid–liquid.

  11. Piroxicam-β-cyclodextrin: a GI safer piroxicam.

    Science.gov (United States)

    Scarpignato, C

    2013-01-01

    Although NSAIDs are very effective drugs, their use is associated with a broad spectrum of adverse reactions in the liver, kidney, cardiovascular (CV) system, skin and gut. Gastrointestinal (GI) side effects are the most common and constitute a wide clinical spectrum ranging from dyspepsia, heartburn and abdominal discomfort to more serious events such as peptic ulcer with life-threatening complications of bleeding and perforation. The appreciation that CV risk is also increased further complicates the choices of physicians prescribing anti-inflammatory therapy. Despite prevention strategies should be implemented in patients at risk, gastroprotection is often underused and adherence to treatment is generally poor. A more appealing approach would be therefore to develop drugs that are devoid of or have reduced GI toxicity. Gastro- duodenal mucosa possesses many defensive mechanisms and NSAIDs have a deleterious effect on most of them. This results in a mucosa less able to cope with even a reduced acid load. NSAIDs cause gastro-duodenal damage, by two main mechanisms: a physiochemical disruption of the gastric mucosal barrier and systemic inhibition of gastric mucosal protection, through inhibition of cyclooxygenase (COX, PG endoperoxide G/H synthase) activity of the GI mucosa. However, against a background of COX inhibition by anti-inflammatory doses of NSAIDs, their physicochemical properties, in particular their acidity, underlie the topical effect leading to short-term damage. It has been shown that esterification of acidic NSAIDs suppresses their gastrotoxicity without adversely affecting anti-inflammatory activity. Another way to develop NSAIDs with better GI tolerability is to complex these molecules with cyclodextrins (CDs), giving rise to so-called "inclusion complexes" that can have physical, chemical and biological properties very different from either those of the drug or the cyclodextrin. Complexation of NSAIDs with β-cyclodextrin potentially leads to a

  12. Phase solubility, 1H NMR and molecular modelling studies of bupivacaine hydrochloride complexation with different cyclodextrin derivates

    Science.gov (United States)

    Jug, Mario; Mennini, Natascia; Melani, Fabrizio; Maestrelli, Francesca; Mura, Paola

    2010-11-01

    A novel method, which simultaneously exploits experimental (NMR) and theoretically calculated data obtained by a molecular modelling technique, was proposed, to obtain deeper insight into inclusion geometry and possible stereoselective binding of bupivacaine hydrochloride with selected cyclodextrin derivatives. Sulphobuthylether-β-cyclodextrin and water soluble polymeric β-cyclodextrin demonstrated to be the best complexing agents for the drug, resulting in formation of the most stable inclusion complexes with the highest increase in aqueous drug solubility. The drug-carrier binding modes with these cyclodextrins and phenomena which may be directly related to the higher stability and better aqueous solubility of complexes formed were discussed in details.

  13. Influencing of resorption and side-effects of salicylic acid by complexing with β-cyclodextrin

    International Nuclear Information System (INIS)

    Szejtli, J.; Gerloczy, A.; Sebestyen, G.; Fonagy, A.

    1981-01-01

    After oral administration of 14 C-labelled salicylic acid and its β-cyclodextrin complex to rats, the radioactivity level of the blood reached its maximum during the first 2 h. The blood level obtained with the complex is somewhat but not significantly lower than with free acid. Since the resorption of cyclodextrin is a considerably slower process, it is very likely that the resorption of salicylic acid takes place in the form of free acid after dissociation of the complex. The urinary excretion cumulative curves showed that the free salicylic acid was completely excreted, while about 10% of the salicylic acid administered in the form of complex is lost. The cyclodextrin complex formation increased the pK values of all hydroxybenzoic acids. Direct observations revealed that complex formation decreased the stomach-irritating effect of salicylic acid. The ratio of radioactivity was nearly the same in the organs of animals treated by both free salicylic and cyclodextrin complex. (author)

  14. Influence of the substitution of β-cyclodextrins by cationic groups on the complexation of organic anions

    International Nuclear Information System (INIS)

    Hbaieb, S.; Kalfat, R.; Chevalier, Y.; Amdouni, N.; Parrot-Lopez, H.

    2008-01-01

    The inclusion complexation of the organic anion, dansyl-acid, by cationic derivatives of β-cyclodextrin has been investigated. A series of cationic β-cyclodextrins with various positive charge has been synthesized by selective functionalization of the primary face of β-cyclodextrin with amino groups. The complexes were of the 1:1 stoichiometry; the stability constants (K 11 ) have been evaluated from UV-Vis measurements by application of the Benesi-Hildebrand equation. The presence of amino groups increased the complexation ability. β-cyclodextrin fully substituted at the primary face with amino groups showed the strongest inclusion binding ability towards the dansyl-acid guest. The enhanced complexation for anions was ascribed to the cationic amino groups. A simple thermodynamic model of the electrostatic contribution to the complexation is presented

  15. Spectral and theoretical study on complexation of sulfamethoxazole with β- and HPβ-cyclodextrins in binary and ternary systems

    Science.gov (United States)

    Varghese, Beena; Suliman, FakhrEldin O.; Al-Hajri, Aalia; Al Bishri, Nahed Surur S.; Al-Rwashda, Nathir

    2018-02-01

    The inclusion complexes of sulfamethoxazole (SMX) with β-cyclodextrin (βCD) and (2-hydroxypropyl) β-cyclodextrin (HPβCD) were prepared. Fluorescence spectroscopy and electrospray mass spectrometry, ESI-MS, were used to investigate and characterize the inclusion complexation of SMX with cyclodextrins in solutions. Whereas in the solid state the complexes were characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) and Raman techniques. Enhanced twisted intramolecular charge transfer (TICT), emission as well as local excited (LE) bands were observed upon addition of HPβCD indicate that SMX enters deeper into the cyclodextrins cavity. The stoichiometries and association constants of these complexes have been determined by monitoring the fluorescence data. The effect of presence of ternary components like arginine and cysteine on the complexation efficiency of SMX with cyclodextrins was investigated. Molecular Dynamic simulations were also performed to shed an atomistic insight into the complexation mechanism. The results obtained showed that complexes of SMX with both cyclodextrins are stabilized in aqueous media by strong hydrogen bonding interactions.

  16. Novel ?-cyclodextrin?eosin conjugates

    OpenAIRE

    Benkovics, G?bor; Afonso, Damien; Darcsi, Andr?s; B?ni, Szabolcs; Conoci, Sabrina; Fenyvesi, ?va; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy an...

  17. Bioadhesive tablets containing cyclodextrin complex of itraconazole for the treatment of vaginal candidiasis.

    Science.gov (United States)

    Cevher, Erdal; Açma, Ayşe; Sinani, Genada; Aksu, Buket; Zloh, Mire; Mülazımoğlu, Lütfiye

    2014-08-01

    Itraconazole (ITR) is commonly used in the treatment of Candida infections. It has a nephrotoxic effect and low bioavailability in patients who suffer from renal insufficiency, and its poor solubility in water makes ITR largely unavailable. Cyclodextrins (CyDs) are used to form inclusion complexes with drugs to improve their aqueous solubility and to reduce their side effects. In this study, ITR was complexed with γ-cyclodextrin (γ-CyD), hydroxypropyl-β-cyclodextrin (HP-β-CyD), methyl-β-cyclodextrin (Met-β-CyD) and sulphobutyl ether-β-cyclodextrin (SBE7-β-CyD) to increase its water solubility and to reduce the side effects of the drug without decreasing antifungal activity. Complex formation between ITR and CyDs was evaluated using SEM, (1)H NMR and XRD studies. The antifungal activity of the complexes was analyzed on Candida albicans strains, and the susceptibility of the strains was found to be higher for the ITR-SBE7-β-CyD complex than for the complexes that were prepared with other CyDs. Vaginal bioadhesive sustained release tablet formulations were developed using the ITR-SBE7-β-CyD inclusion complex to increase the residence time of ITR in the vagina, thereby boosting the efficacy of the treatment. The swelling, matrix erosion and bioadhesion properties of formulations and the drug release rate of these tablets were analyzed, and the most therapeutically effective vaginal formulation was determined. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Study in aqueous solution of the praseodymium inclusion in β-cyclodextrin in 2 M of NaCl

    International Nuclear Information System (INIS)

    De la Cruz M, N.

    2013-01-01

    In the fission of uranium to produce electricity, generated between the fission products which are the lanthanides and actinides that at any given time may come into contact with aqueous media, because of this, praseodymium was including in the β-cyclodextrin in order to increase the solubility and stability of praseodymium by forming inclusion complexes Praseodymium-β-cyclodextrin (Pr-β-Cd). The inclusion study was conducted in a proportion of praseodymium and β-cyclodextrin. Infrared spectra, Raman and X-ray diffraction showed the presence of praseodymium and β-cyclodextrin in the inclusion complex, in both proportions. The analysis by scanning electron microscopy confirmed the inclusion of praseodymium in βcyclodextrin. In general, the results of characterization obtained by these techniques show the formation of the inclusion complex. Furthermore, the behaviour of praseodymium inclusion in the β-cyclodextrin was studied in 2 M NaCl at 303 K and free-CO 2 conditions. For this reason, we used two methods: spectrophotometric and potentiometric titration direct of praseodymium-β-cyclodextrin, the data were treated graphically and with the program SUPERQUAD, respectively. The values obtained for praseodymium by spectrophotometric method was: log β 1 = -8.75 calculated graphically and with the potentiometric method, using program SUPERQUAD were logβ 1,OH = -8.73 ± 0.01 logβ 1,2OH = -18.27 ± 0.16 and logβ 1,3OH = -26.44 ± 0.02 obtained simultaneously. (Author)

  19. Synthesis of per-6-guanidinylated cyclodextrins

    Czech Academy of Sciences Publication Activity Database

    Kraus, Tomáš; Buděšínský, Miloš; Závada, Jiří

    2006-01-01

    Roč. 47, č. 5 (2006), s. 679-681 ISSN 0040-4039 R&D Projects: GA ČR(CZ) GA203/03/0087; GA ČR(CZ) GP203/01/D082 Institutional research plan: CEZ:AV0Z40550506 Keywords : cyclodextrins * guanidine Subject RIV: CC - Organic Chemistry Impact factor: 2.509, year: 2006

  20. Engineering of factors determining alpha-amylase and cyclodextrin glycosyltransferase specificity in the cyclodextrin glycosyltransferase from Thermoanaerobacterium thermosulfurigenes EM1

    NARCIS (Netherlands)

    Wind, RD; Buitelaar, RM; Dijkhuizen, L

    1998-01-01

    The starch-degrading enzymes alpha-amylase and cyclodextrin glycosyltransferase (CGTase) are functionally and structurally closely related, with CGTases containing two additional domains (called D and E) compared to the three domains of alpha-amylases (A, B and C). Amino acid residue 196

  1. ESR technique for noninvasive way to quantify cyclodextrins effect on cell membranes

    International Nuclear Information System (INIS)

    Grammenos, A.; Mouithys-Mickalad, A.; Guelluy, P.H.; Lismont, M.; Piel, G.; Hoebeke, M.

    2010-01-01

    Research highlights: → ESR: a new tool for cyclodextrins study on living cells. → Cholesterol and phospholipid extraction by Rameb in a dose- and time-dependent way. → Extracted phospholipids and cholesterol form stable aggregates. → ESR spectra show that lipid rafts are damaged by Rameb. → Quantification of the cholesterol extraction on cell membranes in a noninvasive way. -- Abstract: A new way to study the action of cyclodextrin was developed to quantify the damage caused on cell membrane and lipid bilayer. The Electron Spin Resonance (ESR) spectroscopy was used to study the action of Randomly methylated-beta-cyclodextrin (Rameb) on living cells (HCT-116). The relative anisotropy observed in ESR spectrum of nitroxide spin probe (5-DSA and cholestane) is directly related to the rotational mobility of the probe, which can be further correlated with the microviscosity. The use of ESR probes clearly shows a close correlation between cholesterol contained in cells and cellular membrane microviscosity. This study also demonstrates the Rameb ability to extract cholesterol and phospholipids in time- and dose-dependent ways. In addition, ESR spectra enabled to establish that cholesterol is extracted from lipid rafts to form stable aggregates. The present work supports that ESR is an easy, reproducible and noninvasive technique to study the effect of cyclodextrins on cell membranes.

  2. Cyclodextrin-facilitated bioconversion of 17 beta-estradiol by a phenoloxidase from Mucuna pruriens cell cultures

    NARCIS (Netherlands)

    Woerdenbag, H.J.; Pras, N.; Frijlink, H.W.; Lerk, C.F.; Malingré, T.M.

    1990-01-01

    After complexation with beta-cyclodextrin, the phenolic steroid 17 beta-estradiol could be ortho-hydroxylated into a catechol, mainly 4-hydroxyestradiol, by a phenoloxidase from in vitro grown cells of Mucuna pruriens. By complexation with beta-cyclodextrin the solubility of the steroid increased

  3. Inhibition of interaction between epigallocatechin-3-gallate and myofibrillar protein by cyclodextrin derivatives improves gel quality under oxidative stress.

    Science.gov (United States)

    Zhang, Yumeng; Chen, Lin; Lv, Yuanqi; Wang, Shuangxi; Suo, Zhiyao; Cheng, Xingguang; Xu, Xinglian; Zhou, Guanghong; Li, Zhixi; Feng, Xianchao

    2018-06-01

    High levels of polyphenols can interact with myofibrillar proteins (MPs), causing damage to a MP emulsion gel. In this study, β-cyclodextrins were used to reduce covalent and non-covalent interaction between epigallocatechin-3-gallate (EGCG) and MPs under oxidative stress. The loss of both thiol and free amine groups and the unfolding of MPs caused by EGCG (80 μM/g protein) were significantly prevented by β-cyclodextrins, and the structural stability and solubility were improved. MP emulsion gel treated with EGCG (80 μM/g protein) had the highest cooking loss (68.64%) and gel strength (0.51 N). Addition of β-cyclodextrins significantly reduced cooking loss (26.24-58.20%) and improved gel strength (0.31-0.41 N) of MP emulsion gel jeopardized by EGCG under oxidative stress. Damage to the emulsifying properties of MPs caused by EGCG was significantly prevented by addition of β-cyclodextrins. β-cyclodextrins reduced interaction between EGCG and MPs in the order Methyl-β-cyclodextrin > (2-Hydroxypropyl)-β-cyclodextrin > β-cyclodextrin. In absence of EGCG, addition of β-cyclodextrins partly protected MPs from oxidative attack and improved its solubility. It is concluded that β-cyclodextrins does not markedly reduce the antioxidant ability of EGCG according to carbonyl analysis, and can effectively increase EGCG loading to potentially provide more durable antioxidant effect for meat products during processing, transportation and storage. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Influence of the substitution of {beta}-cyclodextrins by cationic groups on the complexation of organic anions

    Energy Technology Data Exchange (ETDEWEB)

    Hbaieb, S. [U.R. Physico-Chimie des Materiaux Solides, Faculte des Sciences de Tunis, Manar II, 2092 Tunis (Tunisia)], E-mail: Souhairabouchaira@yahoo.fr; Kalfat, R. [U.R. Physico-Chimie des Materiaux Solides, Faculte des Sciences de Tunis, Manar II, 2092 Tunis (Tunisia); Chevalier, Y. [Laboratoire d' Automatique et de Genie des Procedes (LAGEP), UMR 5007 CNRS-Universite Claude Bernard Lyon 1, 69622 Villeurbanne (France)], E-mail: chevalier@lagep.univ-lyon1.fr; Amdouni, N. [U.R. Physico-Chimie des Materiaux Solides, Faculte des Sciences de Tunis, Manar II, 2092 Tunis (Tunisia); Parrot-Lopez, H. [Institut de Chimie et Biochimie Moleculaires et Supramoleculaires (ICBMS), UMR 5246 CNRS-Universite Claude Bernard Lyon 1, 69622 Villeurbanne (France)], E-mail: helene.parrot@univ-lyon1.fr

    2008-07-01

    The inclusion complexation of the organic anion, dansyl-acid, by cationic derivatives of {beta}-cyclodextrin has been investigated. A series of cationic {beta}-cyclodextrins with various positive charge has been synthesized by selective functionalization of the primary face of {beta}-cyclodextrin with amino groups. The complexes were of the 1:1 stoichiometry; the stability constants (K{sub 11}) have been evaluated from UV-Vis measurements by application of the Benesi-Hildebrand equation. The presence of amino groups increased the complexation ability. {beta}-cyclodextrin fully substituted at the primary face with amino groups showed the strongest inclusion binding ability towards the dansyl-acid guest. The enhanced complexation for anions was ascribed to the cationic amino groups. A simple thermodynamic model of the electrostatic contribution to the complexation is presented.

  5. The effects of cyclodextrins on drug release from fatty suppository bases : I. In vitro observations

    NARCIS (Netherlands)

    Frijlink, H.W.; Eissens, Anko; Schoonen, Adelbert; Lerk, C.F.

    The effect of cyclodextrins on suppository drug release was investigated. Complexes of several lipophilic drugs with β- and/or γ-cyclodextrin were prepared using the coprecipitation method. The formation of true complexes was confirmed by DSC and an 'ether-wash' method. Witepsol H15 suppositories

  6. Alpha-cyclodextrins reversibly capped with disulfide bonds

    Czech Academy of Sciences Publication Activity Database

    Kumprecht, Lukáš; Buděšínský, Miloš; Bouř, Petr; Kraus, Tomáš

    2010-01-01

    Roč. 34, č. 10 (2010), s. 2254-2260 ISSN 1144-0546 R&D Projects: GA AV ČR IAA400550810 Institutional research plan: CEZ:AV0Z40550506 Keywords : cyclodextrins * disulfide bond * dynamic covalent bond Subject RIV: CC - Organic Chemistry Impact factor: 2.631, year: 2010

  7. Cyclodextrin inclusion complex to improve physicochemical properties of herbicide bentazon: exploring better formulations.

    Directory of Open Access Journals (Sweden)

    Claudia Yáñez

    Full Text Available The knowledge of the host-guest complexes using cyclodextrins (CDs has prompted an increase in the development of new formulations. The capacity of these organic host structures of including guest within their hydrophobic cavities, improves physicochemical properties of the guest. In the case of pesticides, several inclusion complexes with cyclodextrins have been reported. However, in order to explore rationally new pesticide formulations, it is essential to know the effect of cyclodextrins on the properties of guest molecules. In this study, the inclusion complexes of bentazon (Btz with native βCD and two derivatives, 2-hydroxypropyl-β-cyclodextrin (HPCD and sulfobutylether-β-cyclodextrin (SBECD, were prepared by two methods: kneading and freeze-drying, and their characterization was investigated with different analytical techniques including Fourier transform infrared spectroscopy (FT-IR, differential thermal analysis (DTA, X-ray diffractometry (XRD and differential pulse voltammetry (DPV. All these approaches indicate that Btz forms inclusion complexes with CDs in solution and in solid state, with a stoichiometry of 1:1, although some of them are obtained in mixtures with free Btz. The calculated association constant of the Btz/HPCD complex by DPV was 244±19 M(-1 being an intermediate value compared with those obtained with βCD and SBECD. The use of CDs significantly increases Btz photostability, and depending on the CDs, decreases the surface tension. The results indicated that bentazon forms inclusion complexes with CDs showing improved physicochemical properties compared to free bentazon indicating that CDs may serve as excipient in herbicide formulations.

  8. Nanodiamonds in sugar rings: an experimental and theoretical investigation of cyclodextrin-nanodiamond inclusion complexes.

    Science.gov (United States)

    Voskuhl, Jens; Waller, Mark; Bandaru, Sateesh; Tkachenko, Boryslav A; Fregonese, Carlo; Wibbeling, Birgit; Schreiner, Peter R; Ravoo, Bart Jan

    2012-06-21

    We report on the noncovalent interactions of nanodiamond carboxylic acids derived from adamantane, diamantane, and triamantane with β- and γ-cyclodextrins. The water solubility of the nanodiamonds was increased by attaching an aromatic dicarboxylic acid via peptide coupling. Isothermal titration calorimetry experiments were performed to determine the thermodynamic parameters (K(a), ΔH, ΔG and ΔS) for the host-guest inclusion. The stoichiometry of the complexes is invariably 1:1. It was found that K(a), ΔG and ΔH of inclusion increase for larger nanodiamonds. ΔS is generally positive, in particular for the largest nanodiamonds. β-Cyclodextrin binds all nanodiamonds, γ-cyclodextrin clearly prefers the most bulky nanodiamonds. The interaction of 9-triamantane carboxylic acid shows one of the strongest complexation constants towards γ-cyclodextrin ever reported, K(a) = 5.0 × 10(5) M(-1). In order to gain some insight into the possible structural basis of these inclusion complexes we performed density functional calculations at the B97-D3/def2-TZVPP level of theory.

  9. Preparation and characterization of thermal-responsive non-woven poly (propylene) materials grafted with N-isopropylacrylamide/β-cyclodextrin

    DEFF Research Database (Denmark)

    Amiri, Setareh; Zadhoush, Ali; Mallakpour, Shadpour

    2013-01-01

    A temperature-sensitive hydrogel was successfully grafted on the surface of non-woven poly(propylene) materials. This was carried out by the application of unmodified β-cyclodextrin and N-isopropylacrylamide monomer in order to develop new functional hydrogels for textile science and technology......(N-isopropylacrylamide) and β-cyclodextrin components on the surface of the textile. Unmodified β-cyclodextrin content was estimated by the use of elemental analysis to be 97 µg/cm2. The water uptake measurements and differential scanning calorimetry analyses showed that the hydrogel maintained its temperature...... of smart textiles which possess the temperature-sensitive property of poly(N-isopropylacrylamide) and the ability of inclusion complex formation with guest molecules due to the presence of unmodified β-cyclodextrin in the hydrogel network....

  10. Cyclodextrin-supported organic matrix for application of MALDI-MS for forensics. Soft-ionization to obtain protonated molecules of low molecular weight compounds

    International Nuclear Information System (INIS)

    Yonezawa, Tetsu; Asano, Takashi; Fujino, Tatsuya; Nishihara, Hiroshi

    2013-01-01

    Highlights: ► MALDI-MS applications for drug identification in forensic science is investigated. ► Cyclodextrin-supported organic matrices strongly suppress the obstacle peaks of organic matrix compounds. ► Cyclodextrin-supported organic matrices also suppress the alkali adducted molecule peaks. ► Sugar units of cyclodextrins work for this specific features. - Abstract: A mass measurement technique for detecting low-molecular-weight drugs with a cyclodextrin-supported organic matrix was investigated. By using cyclodextrin-supported 2,4,6-trihydroxyacetophenone (THAP), the matrix-related peaks of drugs were suppressed. The peaks of protonated molecules of the sample and THAP were mainly observed, and small fragments were detected in a few cases. Despite the Na + and K + peaks were observed in the spectrum, Na + or K + adduct sample molecules were undetected, owing to the sugar units of cyclodextrin. The advantages of MALDI-MS with cyclodextrin-supported matrices as an analytical tool for forensic samples are discussed. The suppression of alkali adducted molecules and desorption process are also discussed

  11. Ficaria verna Huds. extracts and their β-cyclodextrin supramolecular systems

    Directory of Open Access Journals (Sweden)

    Hădărugă Nicoleta G

    2012-03-01

    Full Text Available Abstract Background Obtaining new pharmaceutical materials with enhanced properties by using natural compounds and environment-friendly methods is a continuous goal for scientists. Ficaria verna Huds. is a widespread perennial plant with applications in the treat of haemorrhoids and to cure piles; it has also anti-inflammatory, astringent, and antibiotic properties. The goal of the present study is the obtaining and characterization of new F. verna extract/β-cyclodextrin complexes by using only natural compounds, solvents, and environment-friendly methods in order to increase the quality and acceptability versus toxicity indicator. Thus, the flavonoid content (as quercetin of Ficaria verna Huds. flowers and leaves from the West side of Romania was determined and correlated with their antioxidant activity. Further, the possibility of obtaining β-cyclodextrin supramolecular systems was studied. Results F. verna flowers and leaves extracts were obtained by semi-continuous solid-liquid extraction. The raw concentrated extract was spectrophotometrically analyzed in order to quantify the flavonoids from plant parts and to evaluate the antioxidant activity of these extracts. The F. verna extracts were used for obtaining β-cyclodextrin complexes; these were analyzed by scanning electron microscopy and Karl Fischer water titration; spectrophotometry was used in order to quantifying the flavonoids and evaluates the antioxidant activity. A higher concentration of flavonoids of 0.5% was determined in complexes obtained by crystallisation method, while only a half of this value was calculated for kneading method. The antioxidant activity of these complexes was correlated with the flavonoid content and this parameter reveals possible controlled release properties. Conclusions The flavonoid content of F. verna Huds. from the West side of Romania (Banat county is approximately the same in flowers and leaves, being situated at a medium value among other

  12. The 2.0-A resolution structure of soybean beta-amylase complexed with alpha-cyclodextrin.

    Science.gov (United States)

    Mikami, B; Hehre, E J; Sato, M; Katsube, Y; Hirose, M; Morita, Y; Sacchettini, J C

    1993-07-13

    New crystallographic findings are presented which offer a deeper understanding of the structure and functioning of beta-amylase, the first known exo-type starch-hydrolyzing enzyme. A refined three-dimensional structure of soybean beta-amylase, complexed with the inhibitor alpha-cyclodextrin, has been determined at 2.0-A resolution with a conventional R-value of 17.5%. The model contains 491 amino acid residues, 319 water molecules, 1 sulfate ion, and 1 alpha-cyclodextrin molecule. The protein consists of a core with an (alpha/beta)8 supersecondary structure, plus a smaller globular region formed by long loops (L3, L4, and L5) extending from beta-strands beta 3, beta 4, and beta 5. Between the two regions is a cleft that opens into a pocket whose floor contains the postulated catalytic center near the carboxyl group of Glu 186. The annular alpha-cyclodextrin binds in (and partly projects from) the cleft with its glucosyl O-2/O-3 face abutting the (alpha/beta)8 side and with its alpha-D(1 --> 4) glucosidic linkage progression running clockwise as viewed from that side. The ligand does not bind deeply enough to interact with the carboxyl group of Glu 186. Rather, it occupies most of the cleft entrance, strongly suggesting that alpha-cyclodextrin inhibits catalysis by blocking substrate access to the more deeply located reaction center. Of the various alpha-cyclodextrin interactions with protein residues in loops L4, L5, L6, and L7, most notable is the shallow inclusion complex formed with Leu 383 (in L7, on the core side of the cleft) through contacts of its methyl groups with the C-3 atoms of four of the ligand's D-glucopyranosyl residues. All six residues of the bound alpha-cyclodextrin are of 4C1 conformation and are joined by alpha-1,4 linkages with similar torsional angles to form a nearly symmetrical torus as reported for crystalline inclusion complexes with alpha-cyclodextrin. We envision a significant role for the methyl groups of Leu 383 at the cleft entrance

  13. Self-assembly of cyclodextrins

    DEFF Research Database (Denmark)

    Fülöp, Z.; Kurkov, S.V.; Nielsen, T.T.

    2012-01-01

    The design of functional cyclodextrin (CD) nanoparticles is a developing area in the field of nanomedicine. CDs can not only help in the formation of drug carriers but also increase the local concentration of drugs at the site of action. CD monomers form aggregates by self-assembly, a tendency...... that increases upon formation of inclusion complexes with lipophilic drugs. However, the stability of such aggregates is not sufficient for parenteral administration. In this review CD polymers and CD containing nanoparticles are categorized, with focus on self-assembled CD nanoparticles. It is described how...

  14. Porous silicon-cyclodextrin based polymer composites for drug delivery applications.

    Science.gov (United States)

    Hernandez-Montelongo, J; Naveas, N; Degoutin, S; Tabary, N; Chai, F; Spampinato, V; Ceccone, G; Rossi, F; Torres-Costa, V; Manso-Silvan, M; Martel, B

    2014-09-22

    One of the main applications of porous silicon (PSi) in biomedicine is drug release, either as a single material or as a part of a composite. PSi composites are attractive candidates for drug delivery systems because they can display new chemical and physical characteristics, which are not exhibited by the individual constituents alone. Since cyclodextrin-based polymers have been proven efficient materials for drug delivery, in this work β-cyclodextrin-citric acid in-situ polymerization was used to functionalize two kinds of PSi (nanoporous and macroporous). The synthesized composites were characterized by microscopy techniques (SEM and AFM), physicochemical methods (ATR-FTIR, XPS, water contact angle, TGA and TBO titration) and a preliminary biological assay was performed. Both systems were tested as drug delivery platforms with two different model drugs, namely, ciprofloxacin (an antibiotic) and prednisolone (an anti-inflammatory), in two different media: pure water and PBS solution. Results show that both kinds of PSi/β-cyclodextrin-citric acid polymer composites, nano- and macro-, provide enhanced release control for drug delivery applications than non-functionalized PSi samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. β-Cyclodextrin-curcumin complex inhibit telomerase gene ...

    African Journals Online (AJOL)

    Yomi

    2011-12-21

    Dec 21, 2011 ... have various applications in cancer therapy. But, its low water solubility and bioavailability is possible for poor drug delivery of curcumin. In this study, we prepared β-cyclodextrin-curcumin complex to determine the inhibitory effect of this drug on telomerase gene expression. Curcumin was encapsulated.

  16. NMR spectroscopic characterization of β-cyclodextrin inclusion complex with vanillin

    International Nuclear Information System (INIS)

    Pirnau, Adrian; Bogdan, Mircea; Floare, Calin G

    2009-01-01

    The inclusion of vanillin by β-cyclodextrin was investigated by 1 H NMR. The continuous variation technique was used to evidence the formation of soluble 1:1 complex in aqueous solution. The association constant of vanillin with β-cyclodextrin has been obtained at 298 K by fitting the experimental chemical shifts differences, Δδ obs δ free - δ obs of the observed guest and host protons, with a non-linear regression method. Besides the effective association constant, the fitting procedure allows a precise determination of all chemical shift parameters characterizing the pure complex. They can by used for an analysis of the geometry of the molecular complex in solution.

  17. Empirical, thermodynamic and quantum-chemical investigations of inclusion complexation between flavanones and (2-hydroxypropyl)-cyclodextrins.

    Science.gov (United States)

    Liu, Benguo; Li, Wei; Nguyen, Tien An; Zhao, Jian

    2012-09-15

    The inclusion complexation of (2-hydroxypropyl)-cyclodextrins with flavanones was investigated by phase solubility measurements, as well as thermodynamic and quantum chemical methods. Inclusion complexes were formed between (2-hydroxypropyl)-α-cyclodextrin (HP-α-CD), (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD), (2-hydroxypropyl)-γ-cyclodextrin (HP-γ-CD) and β-cyclodextrin (β-CD) and four flavanones (naringenin, naringin, hesperetin and dihydromyricetin) in aqueous solutions and their phase solubility was determined. For all the flavanones, the stability constants of their complexes formed with different CDs followed the rank order: HP-β-CD (MW 1540)>HP-β-CD (MW 1460)>HP-β-CD (MW 1380)>β-CD>HP-γ-CD>HP-α-CD. Experimental results and quantum chemical calculations showed that the ability of flavanones to form inclusion complex with (2-hydroxypropyl)-cyclodextrins was determined by both the steric effect and hydrophobicity of the flavanones. For flavanones that have similar molecular volumes, the hydrophobicity of the molecule was the main determining factor of its ability to form inclusion complexes with HP-β-CD, and the hydrophobicity parameter Log P is highly correlated with the stability constant of the complexes. Results of thermodynamic study demonstrated that hydrophobic interaction is the main driving force for the formation process of the flavanone-CD inclusion complexes. Quantum chemical analysis of the most active hydroxyl groups and HOMO (the highest occupied molecular orbital) showed that the B ring of the flavanones was most likely involved in hydrogen bonding with the side groups in the cavity of the CDs, through which the inclusion complex was stabilised. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Experimental, molecular docking investigations and bioavailability study on the inclusion complexes of finasteride and cyclodextrins

    Directory of Open Access Journals (Sweden)

    Mady FM

    2017-06-01

    Full Text Available Fatma M Mady,1,2 Usama Farghaly Aly2 1Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Taibah University, Medina, Saudi Arabia; 2Department of Pharmaceutics, Faculty of Pharmacy, Minia University, Minia, Egypt Abstract: Finasteride (FIN is a Class II candidate of the Biopharmaceutics Classification System (BCS. The lipophilic cavity of cyclodextrins (CyDs enables it to construct a non-covalent inclusion complex with different insoluble drugs. Only β-cyclodextrin (β-CyD and hydroxypropyl-β-CyD (HP-β-CyD have been previously examined with FIN. This study aimed to investigate the consistence of FIN with different kinds of β-CyDs, including dimethyl-β-cyclodextrin (DM-β-CyD, carboxymethyl-β-cyclodextrin (CM-β-CyD, HP-β-CyD, sulfobutyl ether-β-cyclodextrin (SBE-β-CyD, and β-CyD, by the coprecipitation method. The resultant inclusion systems were characterized by differential scanning calorimetry, infrared spectroscopy, X-ray diffractometry, and dissolution studies. Moreover, molecular docking for the selected inclusion systems was carried out to explore the suitable arrangements of FIN in the cavity of β-CyD or its derivatives. The results suggested that the DM-β-CyD inclusion system gave the higher complexation efficiency for improvement in solubility of FIN and hence enhancement of its bioavailability. Pharmacokinetic parameters displayed a higher absorption rate and higher area under the curve of the FIN/DM-β-CyD inclusion complex when compared with the drug alone, which indicates an improvement in the absorption and bioavailability of FIN in the DM-β-CyD inclusion system. Keywords: finasteride, cyclodextrins, molecular docking, pharmacokinetics, bioavailability

  19. Comparative studies of the influence of cyclodextrins on the stability of the sunscreen agent, 2-ethylhexyl-p-methoxycinnamate.

    Science.gov (United States)

    Scalia, Santo; Casolari, Alberto; Iaconinoto, Antonietta; Simeoni, Silvia

    2002-11-07

    The effects of beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the base-catalyzed degradation and light-induced decomposition of the sunscreen agent, trans-2-ethylhexyl-p-methoxycinnamate (trans-EHMC) were investigated. Reversed-phase liquid chromatography was used to study the interaction between natural and modified cyclodextrins, added to the mobile phase, and the sunscreen. Among the available cyclodextrins (beta-CD, HP-beta-CD, hydroxypropyl-alpha-cyclodextrin and hydroxypropyl-gamma-cyclodextrin), only HP-beta-CD and beta-CD produced a significant decrease in the chromatographic retention of trans-EHMC. The complexation of the sunscreen agent with HP-beta-CD and beta-CD was confirmed by thermal analysis and nuclear magnetic resonance spectroscopy. beta-CD depressed the decomposition of trans-EHMC in alkaline solutions more effectively than HP-beta-CD. Moreover, the irradiation-induced degradation of the sunscreen agent in emulsion vehicles was reduced by complexation with beta-CD (the extent of degradation was 26.1% for the complex compared to 35.8% for free trans-EHMC) whereas HP-beta-CD had no significant effect. Therefore, the complex of beta-CD with trans-EHMC enhances the chemical- and photo-stability of the sunscreen agent. Moreover, it limits adverse interactions of the UV filter with other formulation ingredients.

  20. Phosphane-Based Cyclodextrins as Mass Transfer Agents and Ligands for Aqueous Organometallic Catalysis

    Directory of Open Access Journals (Sweden)

    Eric Monflier

    2012-11-01

    Full Text Available The replacement of hazardous solvents and the utilization of catalytic processes are two key points of the green chemistry movement, so aqueous organometallic catalytic processes are of great interest in this context. Nevertheless, these processes require not only the use of water-soluble ligands such as phosphanes to solubilise the transition metals in water, but also the use of mass transfer agents to increase the solubility of organic substrates in water. In this context, phosphanes based on a cyclodextrin skeleton are an interesting alternative since these compounds can simultaneously act as mass transfer agents and as coordinating species towards transition metals. For twenty years, various cyclodextrin-functionalized phosphanes have been described in the literature. Nevertheless, while their coordinating properties towards transition metals and their catalytic properties were fully detailed, their mass transfer agent properties were much less discussed. As these mass transfer agent properties are directly linked to the availability of the cyclodextrin cavity, the aim of this review is to demonstrate that the nature of the reaction solvent and the nature of the linker between cyclodextrin and phosphorous moieties can deeply influence the recognition properties. In addition, the impact on the catalytic activity will be also discussed.

  1. Scutellarin-graft cationic β-cyclodextrin-polyrotaxane: Synthesis, characterization and DNA condensation

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Qi; Ma, Xue; Liao, Xiali; Yang, Bo, E-mail: yangbo6910@sina.com

    2017-02-01

    As a prerequisite of gene delivery in living cells, DNA condensation has attracted more and more attention. In order to improve the efficiencies of polyamine-β-cyclodextrin-based cationic polyrotaxanes (PR-EDA and PR-DETA) as DNA condensation materials, we have designed and prepared two novel scutellarin-grafted cationic polyrotaxanes (PR-EDA-SCU and PR-DETA-SCU), in which scutellarins (SCU), the planar molecules, were conjugated on the cyclodextrin molecules of PR-EDA and PR-DETA. These materials were characterized by 1D and 2D NMR, XRD, TG and DSC. The electrophoresis assays showed that pDNA condensation efficiencies of PR-EDA and PR-DETA were better than that of PR-EDA and PR-DETA. The complexes of PR-EDA, PR-DETA, PR-EDA-SCU and PR-DETA-SCU with pDNA were further investigated by zeta potential and atomic force microscopy analysis. The results indicated that the planar structure of SCU played an important role in improvement of pDNA condensation efficiencies of PR-EDA-SCU and PR-DETA-SCU. The satisfactory pDNA condensation abilities of PR-EDA-SCU and PR-DETA-SCU could be helpful in designing non-viral gene delivery vectors to control gene expression and delivery. - Highlights: • Scutellarin-graft cationic cyclodextrin-polyrotaxans were prepared and characterized. • Scutellarin-graft cationic cyclodextrin-polyrotaxans was abbreviated as PR-(D)EDA-SCU. • The Scutellarin of PR-(D)EDA-SCU may be helpful to DNA condensation. • This study opens new avenues for preparing non-viral gene delivery vectors.

  2. Cyclodextrin-supported organic matrix for application of MALDI-MS for forensics. Soft-ionization to obtain protonated molecules of low molecular weight compounds

    Energy Technology Data Exchange (ETDEWEB)

    Yonezawa, Tetsu, E-mail: tetsu@eng.hokudai.ac.jp [Division of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Asano, Takashi [Division of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Criminal Investigation Laboratory, Metropolitan Police Department, 2-1-1 Kasumigaseki, Chiyoda-ku, Tokyo 100-8929 (Japan); Fujino, Tatsuya [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Nishihara, Hiroshi [Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2013-06-20

    Highlights: ► MALDI-MS applications for drug identification in forensic science is investigated. ► Cyclodextrin-supported organic matrices strongly suppress the obstacle peaks of organic matrix compounds. ► Cyclodextrin-supported organic matrices also suppress the alkali adducted molecule peaks. ► Sugar units of cyclodextrins work for this specific features. - Abstract: A mass measurement technique for detecting low-molecular-weight drugs with a cyclodextrin-supported organic matrix was investigated. By using cyclodextrin-supported 2,4,6-trihydroxyacetophenone (THAP), the matrix-related peaks of drugs were suppressed. The peaks of protonated molecules of the sample and THAP were mainly observed, and small fragments were detected in a few cases. Despite the Na{sup +} and K{sup +} peaks were observed in the spectrum, Na{sup +} or K{sup +} adduct sample molecules were undetected, owing to the sugar units of cyclodextrin. The advantages of MALDI-MS with cyclodextrin-supported matrices as an analytical tool for forensic samples are discussed. The suppression of alkali adducted molecules and desorption process are also discussed.

  3. Study of the β-Cyclodextrin Imipramine Hydrochloride Inclusion Complex and Determination of its Stability Constant (K by UV-Visible Spectroscopy

    Directory of Open Access Journals (Sweden)

    Alamdar Ashnagar

    2007-01-01

    Full Text Available In this research, the interactions of imipramine hydrochloride drug with β- cyclodextrin and the stability constant (K of the inclusion complex formed between them were investigated by using UV-visible spectroscopy. Solutions consisting of a known and constant amount of imipramine hydrochloride and varying amounts of β- cyclodextrin were prepared in 0.1 M phosphate buffer (pH 7.4. The final solutions had cyclodextrin concentrations between 0.0011 and 0.0153 M. UV-visible spectra of each solution was taken at λmax= 250 nm. The absorbances at this wavelength were recorded and plotted against cyclodextrin concentrations. From the graph, the concentrations of free and bound imipramine hydrochloride and free β-cyclodextrin were calculated using the Beer-Lambert law. From these data, the stability constant was calculated and a value of K=52.26±11.41 mol-1L was obtained. The magnitude of the stability constant is discussed in terms of the relative sizes and the chemical natures of β-cyclodextrin and imipramine hydrochloride.

  4. Sol–gel zirconia nanopowders with α-cyclodextrin as organic additive

    International Nuclear Information System (INIS)

    Răileanu, M.; Todan, L.; Crişan, D.; Drăgan, N.; Crişan, M.; Stan, C.; Andronescu, C.; Voicescu, M.; Vasile, B.S.; Ianculescu, A.

    2012-01-01

    Highlights: ► The sol–gel synthesis of a zirconia powder has been performed, in the presence of α-cyclodextrin as organic additive. ► A crystalline powder consisting from a mixture of monoclinic and tetragonal zirconia phases has resulted after the thermal treatment. ► The organic additive acted the role of metal oxides used as doppants for zirconia powders, avoiding phase transformations. ► The α-cyclodextrin made particles to assume spherical shape and reach fairly uniform size and prevented their agglomeration. ► The organic additive led to a certain porous morphology of the zirconia particles that is pores embedded within grains. - Abstract: Nanomaterials present unique structural and physicochemical properties due to their ultra fine size of particles that make them very useful in many domains. The most spectacular applications of nanosized zirconia include ceramics, piezoelectrics, refractories, pigments, solid electrolytes, oxygen sensors, catalysts, ultrafiltration membranes, and chromatography packing materials. Nanostructured zirconia powders can be prepared using various methods, such as sol–gel process, coprecipitation, hydrothermal synthesis, and reverse micelle method. The aim of the present work was to prepare zirconia nanopowders through the sol–gel method, using α-cyclodextrin as organic additive and to establish its influence on the structural and textural properties of the obtained product. A white, amorphous ZrO 2 powder containing α-cyclodextrin was prepared, which became a crystalline, stable one, after removing the organic matter by thermal treatment. The resulted nanocrystalline powder contains both monoclinic and tetragonal zirconia phases and is very stable. It presents a relatively reduced tendency of agglomeration of particles and contains closed pores which are embedded in the zirconia matrix. The zirconia powders were characterized using the following methods: thermal analysis, IR spectroscopy, UV–vis spectroscopy

  5. Spectrophotometric thermodynamic study of orientational isomers formed by inclusion of methyl orange into β-cyclodextrin nanocavity

    DEFF Research Database (Denmark)

    Kompany Zare, Mohsen; Mokhtari, Zeinab; Abdollahi, Hamid

    2012-01-01

    Spectrophotometry has been used to investigate the interaction of methyl orange (MO), an azo dye as a guest, with β-cyclodextrin (CD) as the host. Inclusion of methyl orange into β-cyclodextrin nanocavity leads to two orientational isomers, so-called inclumers, because of the asymmetric structure...

  6. NMR spectroscopic characterization of {beta}-cyclodextrin inclusion complex with vanillin

    Energy Technology Data Exchange (ETDEWEB)

    Pirnau, Adrian; Bogdan, Mircea; Floare, Calin G, E-mail: adrian.pirnau@itim-cj.r [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

    2009-08-01

    The inclusion of vanillin by {beta}-cyclodextrin was investigated by {sup 1}H NMR. The continuous variation technique was used to evidence the formation of soluble 1:1 complex in aqueous solution. The association constant of vanillin with {beta}-cyclodextrin has been obtained at 298 K by fitting the experimental chemical shifts differences, {Delta}{delta}{sub obs} {delta}{sub free} - {delta}{sub obs} of the observed guest and host protons, with a non-linear regression method. Besides the effective association constant, the fitting procedure allows a precise determination of all chemical shift parameters characterizing the pure complex. They can by used for an analysis of the geometry of the molecular complex in solution.

  7. Strong supramolecular control over protein self-assembly using a polyamine decorated β-cyclodextrin as synthetic recognition element

    NARCIS (Netherlands)

    Uhlenheuer, D.A.; Milroy, L.G.; Neirynck, P.; Brunsveld, L.

    2011-01-01

    The supramolecular host molecule heptakis-[6-deoxy-6-(2-aminoethylsulfanyl)]-ß-cyclodextrin provides strong control over protein self-assembly in synthetic supramolecular protein constructs. Mono-functionalization of this modified ß-cyclodextrin with a cysteine residue allows for site-selective

  8. Separation of hydroxynorketamine stereoisomers using capillary electrophoresis with sulfated β-cyclodextrin and highly sulfated γ-cyclodextrin.

    Science.gov (United States)

    Sandbaumhüter, Friederike A; Theurillat, Regula; Thormann, Wolfgang

    2017-08-01

    The racemic N-methyl-d-aspartate receptor antagonist ketamine is used in anesthesia, analgesia and the treatment of depressive disorders. It is known that interactions of hydroxylated norketamine metabolites and 5,6-dehydronorketamine (DHNK) with the α 7 -nicotinic acetylcholine receptor and the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor are responsible for the antidepressive effects. Ketamine and its first metabolite norketamine are not active on these receptors. As stereoselectivity plays a role in ketamine metabolism, a cationic capillary electrophoresis based method capable of resolving and analyzing the stereoisomers of four hydroxylated norketamine metabolites, norketamine and DHNK was developed. The assay is based on liquid/liquid extraction of the analytes from the biological matrix, electrokinetic sample injection across a buffer plug and analysis of the stereoisomers in a phosphate background electrolyte (BGE) at pH 3 comprising a mixture of sulfated β-cyclodextrin (5 mg/mL) and highly sulfated γ-cyclodextrin (0.1%). The method was used to analyze samples of an in vitro study in which ketamine was incubated with equine liver microsomes and in plasma samples of dogs and horses that were collected after an i.v. bolus injection of racemic ketamine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Synthesis of Mono(perfluoroalkyl) Cyclodextrins via Cross Metathesis

    Czech Academy of Sciences Publication Activity Database

    Řezanka, M.; Eignerová, Barbara; Jindřich, J.; Kotora, M.

    -, č. 32 (2010), s. 6256-6262 ISSN 1434-193X R&D Projects: GA AV ČR KAN200200651 Institutional research plan: CEZ:AV0Z40550506 Keywords : metathesis * cyclodextrins * fluorine * alkylation * amphiphiles Subject RIV: CC - Organic Chemistry Impact factor: 3.206, year: 2010

  10. Development of Orodispersible Tablets of Candesartan Cilexetil-β-cyclodextrin Complex

    Directory of Open Access Journals (Sweden)

    Maddukuri Sravya

    2013-01-01

    Full Text Available The aim of this study was to investigate the use of inclusion complexation technique employing β-cyclodextrin in improving the dissolution profile of candesartan cilexetil, a BCS class-II drug, and to formulate the inclusion complex into orodispersible tablets. The inclusion complexes were formed by physical mixing, kneading, coevaporation, and lyophilisation methods. Inclusion complexes were characterized by FTIR, DSC, XRD, NMR, and mass spectral studies. Inclusion complexes prepared using kneading, and lyophilisation techniques in the molar ratio 1 : 5 with β-cyclodextrin were used for formulating orodispersible tablets by direct compression with different superdisintegrants like croscarmellose sodium, crospovidone, sodium starch glycolate, and low substituted hydroxypropyl cellulose in varying concentrations. The directly compressible powder was evaluated for precompression parameters, and the prepared orodispersible tablets were evaluated for postcompression parameters. Drug-excipient compatibility studies showed no interaction, and characterization proved the formation of inclusion complex. In vitro disintegration time was found to be within 3 minutes, and all the formulations showed complete drug release of 100% within 20 minutes. The optimized formulation was found to be stable after 6 months and showed no significant change in drug content. This work proved β-cyclodextrins to be effective solubilizing agent in improving the solubility of poorly water soluble drugs.

  11. Thermal degradation features of peppermint oil in a binary system with Β- cyclodextrin

    Directory of Open Access Journals (Sweden)

    I. A. Omelchenko

    2016-04-01

    Full Text Available Aim. One of the most promising ways of changing physical and chemical properties of the active pharmaceutical ingredient is an encapsulation on a molecular level with the use of cyclodextrins. This makes it possible to create products with the desired activity and controlled distribution in the body. Methods and results. We have studied the thermal decomposition of peppermint oil in binary systems with β-cyclodextrin. It has been found that the thermal degradation of mechanical mixture and inclusion complex of the «host-guest» with the composition of 1:1 passes through different mechanisms. Conclusions. It is shown that the given data of thermal stability are useful for the identification of an inclusion complex «β-CD – peppermint oil» and assessing its complexation, and for the development of technology of medicinal forms of supramolecular complex of β-cyclodextrin and peppermint oil

  12. Capillary electrophoretic enantioseparation of basic drugs using a new single-isomer cyclodextrin derivative and theoretical study of the chiral recognition mechanism.

    Science.gov (United States)

    Liu, Yongjing; Deng, Miaoduo; Yu, Jia; Jiang, Zhen; Guo, Xingjie

    2016-05-01

    A novel single-isomer cyclodextrin derivative, heptakis {2,6-di-O-[3-(1,3-dicarboxyl propylamino)-2-hydroxypropyl]}-β-cyclodextrin (glutamic acid-β-cyclodextrin) was synthesized and used as a chiral selector in capillary electrophoresis for the enantioseparation of 12 basic drugs, including terbutaline, clorprenaline, tulobuterol, clenbuterol, procaterol, carvedilol, econazole, miconazole, homatropine methyl bromide, brompheniramine, chlorpheniramine and pheniramine. The primary factors affecting separation efficiency, which include the background electrolyte pH, the concentration of glutamic acid-β-cyclodextrin and phosphate buffer concentration, were investigated. Satisfactory enantioseparations were obtained using an uncoated fused-silica capillary of 50 cm (effective length 40 cm) × 50 μm id with 120 mM phosphate buffer (pH 2.5-4.0) containing 0.5-4.5 mM glutamic acid-β-cyclodextrin as background electrolyte. A voltage of 20 kV was applied and the capillary temperature was kept at 20°C. The results proved that glutamic acid-β-cyclodextrin was an effective chiral selector for studied 12 basic drugs. Moreover, the possible chiral recognition mechanism of brompheniramine, chlorpheniramine and pheniramine on glutamic acid-β-cyclodextrin was investigated using the semi-empirical Parametric Method 3. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Host-guest complexes of 2-hydroxypropyl-β-cyclodextrin/β-cyclodextrin and nifedipine: 1H NMR, molecular modeling, and dissolution studies

    Science.gov (United States)

    de Araújo, Márcia Valéria Gaspar; Vieira, João Victor Francisco; da Silva, Caroline W. P.; Barison, Andersson; Andrade, George Ricardo Santana; da Costa, Nivan Bezerra; Barboza, Fernanda Malaquias; Nadal, Jessica Mendes; Novatski, Andressa; Farago, Paulo Vitor; Zawadzki, Sônia Faria

    2017-12-01

    Nifedipine (NIF) is a hydrophobic drug widely used for treating cardiovascular diseases. This calcium channel blocker can present a higher apparent solubility by its inclusion into different cyclodextrins (CDs) as host-guest complexes. This paper focused on the structural investigation and dissolution behavior of inclusion complexes prepared with 2-hydroxypropyl-β-cyclodextrin (HPβCD) or β-cyclodextrin (βCD) and NIF. Drug amorphization was observed for HPβCD/NIF and βCD/NIF inclusion complexes by X-ray diffractometry (XRD). The sharp endothermic peak of NIF was not observed for these both host-guest complexes by differential scanning calorimetry (DSC). These results of XRD and DSC provide evidences of complexation between drug and the investigated CDs. 1H and saturation transfer difference nuclear magnetic resonance studies revealed the enhancement in the signal at 2.27 ppm for HPβCD/NIF and βCD/NIF inclusion complexes that corresponded to the methyl groups of NIF from the non-aromatic ring. This result suggested that non-aromatic ring of NIF was inserted into HPβCD and βCD cavities. Considering the mathematical simulations, it was observed that the inclusion process can occur in the both NH-in or NH-out forms. However, since it was used aqueous medium, it is possible to indicate that the obtained host-guest complexes HPβCD/NIF and βCD/NIF are in NH-in form which corresponded to the previous results obtained by 1H NMR experiments. Dissolution assays demonstrated that NIF inclusion complexes improved the drug release nevertheless without changing its biexponential release behavior. These host-guest complexes can be further used as feasible NIF carriers in solid dosage forms.

  14. Fluorescently labeled methyl-beta-cyclodextrin enters intestinal epithelial Caco-2 cells by fluid-phase endocytosis.

    Directory of Open Access Journals (Sweden)

    Ferenc Fenyvesi

    Full Text Available Cyclodextrins are widely used excipients for increasing the bioavailability of poorly water-soluble drugs. Their effect on drug absorption in the gastrointestinal tract is explained by their solubility- and permeability-enhancement. The aims of this study were to investigate penetration properties of fluorescently labeled randomly methylated-beta-cyclodextrin (FITC-RAMEB on Caco-2 cell layer and examine the cellular entry of cyclodextrins on intestinal cells. The permeability of FITC-RAMEB through Caco-2 monolayers was very limited. Using this compound in 0.05 mM concentration the permeability coefficient was 3.35±1.29×10(-8 cm/s and its permeability did not change in the presence of 5 mM randomly methylated-beta-cyclodextrin. Despite of the low permeability, cellular accumulation of FITC-RAMEB in cytoplasmic vesicles was significant and showed strong time and concentration dependence, similar to the characteristics of the macropinocytosis marker Lucifer Yellow. The internalization process was fully inhibited at 0°C and it was drastically reduced at 37°C applying rottlerin, an inhibitor of macropinocytosis. Notably, FITC-RAMEB colocalized with the early endosome organizer Rab5a. These results have revealed that FITC-RAMEB is able to enter intestinal epithelial cells by fluid-phase endocytosis from the apical side. This mechanism can be an additional process which helps to overcome the intestinal barrier and contributes to the bioavailability enhancement of cyclodextrins.

  15. Thermodynamics and structure of inclusion compounds of tauro- and glyco-conjugated bile salts and beta-cyclodextrin

    DEFF Research Database (Denmark)

    Holm, Rene; Shi, Wei; Andersen Hartvig, Rune

    2009-01-01

    The interaction between natural beta-cyclodextrin and bile salts common in rat, dog and man, taurocholate, tauro-beta-muricholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate and glycochenodeoxycholate, was studied using isothermal titration calorimetry, and the str......The interaction between natural beta-cyclodextrin and bile salts common in rat, dog and man, taurocholate, tauro-beta-muricholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate and glycochenodeoxycholate, was studied using isothermal titration calorimetry......, and the structural differences in the interaction were investigated by H-1-ROESY NMR and molecular modeling. The beta-cyclodextrin was selected based upon its frequent use in preformulation and drug formulation as oral excipients for the solubilization of drug substances with low aqueous solubility. All...

  16. Photoinduced electron transfer within porphyrin-cyclodextrin conjugates

    Czech Academy of Sciences Publication Activity Database

    Lang, Kamil; Král, V.; Kapusta, P.; Kubát, Pavel; Vašek, P.

    2002-01-01

    Roč. 43, - (2002), s. 4919-4922 ISSN 0040-4039 R&D Projects: GA ČR GA203/99/1163; GA ČR GA203/01/0634; GA ČR GA203/02/1483 Institutional research plan: CEZ:AV0Z4032918 Keywords : porphyrin-cyclodextrin * chiral aggregate * quenching Subject RIV: CA - Inorganic Chemistry Impact factor: 2.357, year: 2002

  17. Thermodynamics of inclusion complexes of natural and modified cyclodextrins with acetylsalicylic acid and ibuprofen in aqueous solution at 298 K

    Energy Technology Data Exchange (ETDEWEB)

    Castronuovo, Giuseppina, E-mail: giuseppina.castronuovo@unina.it [Department of Chemistry, University Federico II of Naples, Complesso Universitario a Monte S. Angelo, via Cintia, 80126 Naples (Italy); Niccoli, Marcella [Department of Chemistry, University Federico II of Naples, Complesso Universitario a Monte S. Angelo, via Cintia, 80126 Naples (Italy)

    2013-04-10

    Graphical abstract: Complexation forces acting in the association between natural and modified α- and β-cyclodextrins and acetylsalicylic acid (aspirin) or ibuprofen are examined through the analysis of the thermodynamic parameters obtained by isothermal calorimetry. Highlights: ► A calorimetric method is reported to study the association of natural and substituted cyclodextrins with acetylsalicylic acid and ibuprofen. ► The study aims to propose a hypothesis about the forces involved in the interaction. That can be useful for designing new cyclodextrins having suitable characteristics to include specific drugs. ► Enthalpic and entropic contributions on the association are discussed. The differences in the cavity dimensions of the cyclodextrins determine the values of the thermodynamic properties to be very different. - Abstract: Thermodynamic parameters for the association of natural and substituted α-, β-, and γ-cyclodextrins with acetylsalicylic acid, salicylic acid and ibuprofen have been determined by isothermal titration calorimetry. Analysis of the data shows that complexes form, all having 1:1 stoichiometry. The shape-matching between the host and guest is the factor determining the values of the thermodynamic quantities. In the case of the smallest cyclodextrin interacting with acetylsalicylic acid and salicylic acid, the parameters indicate that hydrophobic interactions play the major role. Association occurs through the shallow inclusion of the benzene ring into the cavity. In the case of substituted β-cyclodextrins, instead, inclusion of the benzene ring is deeper and the tight fitting of the guest molecule to the cavity makes the enthalpy and entropy to be both negative. Ibuprofen interacts through its isobutyl group: the values of the association constants are very high for β-cyclodextrins as determined by the large and positive entropies due to the relaxation of water molecules from the cavity and the hydration spheres of the interacting

  18. Thermodynamics of inclusion complexes of natural and modified cyclodextrins with acetylsalicylic acid and ibuprofen in aqueous solution at 298 K

    International Nuclear Information System (INIS)

    Castronuovo, Giuseppina; Niccoli, Marcella

    2013-01-01

    Graphical abstract: Complexation forces acting in the association between natural and modified α- and β-cyclodextrins and acetylsalicylic acid (aspirin) or ibuprofen are examined through the analysis of the thermodynamic parameters obtained by isothermal calorimetry. Highlights: ► A calorimetric method is reported to study the association of natural and substituted cyclodextrins with acetylsalicylic acid and ibuprofen. ► The study aims to propose a hypothesis about the forces involved in the interaction. That can be useful for designing new cyclodextrins having suitable characteristics to include specific drugs. ► Enthalpic and entropic contributions on the association are discussed. The differences in the cavity dimensions of the cyclodextrins determine the values of the thermodynamic properties to be very different. - Abstract: Thermodynamic parameters for the association of natural and substituted α-, β-, and γ-cyclodextrins with acetylsalicylic acid, salicylic acid and ibuprofen have been determined by isothermal titration calorimetry. Analysis of the data shows that complexes form, all having 1:1 stoichiometry. The shape-matching between the host and guest is the factor determining the values of the thermodynamic quantities. In the case of the smallest cyclodextrin interacting with acetylsalicylic acid and salicylic acid, the parameters indicate that hydrophobic interactions play the major role. Association occurs through the shallow inclusion of the benzene ring into the cavity. In the case of substituted β-cyclodextrins, instead, inclusion of the benzene ring is deeper and the tight fitting of the guest molecule to the cavity makes the enthalpy and entropy to be both negative. Ibuprofen interacts through its isobutyl group: the values of the association constants are very high for β-cyclodextrins as determined by the large and positive entropies due to the relaxation of water molecules from the cavity and the hydration spheres of the interacting

  19. Evaluation of piroxicam-β-cyclodextrin as a preemptive analgesic in functional endoscopic sinus surgery

    Directory of Open Access Journals (Sweden)

    G.T. Keleş

    2010-08-01

    Full Text Available The preemptive analgesic efficacy and adverse effects of preoperatively administered piroxicam-β-cyclodextrin for post-endoscopic sinus surgery pain was determined in a prospective, double-blind, randomized, clinical study. Seventy-five American Society of Anesthesiologists status I-II patients, aged 18-65 years, were divided into three groups with similar demographic characteristics: group 1 received 20 mg piroxicam-β-cyclodextrin, group 2 received 40 mg piroxicam-β-cyclodextrin and group 3 received placebo orally before induction of general anesthesia. A blinded observer recorded the incidence and severity of pain at admission to the post-anesthesia care unit (PACU, at 15, 30, and 45 min in the PACU, and 1, 2, 4, 6, and 24 h postoperatively. All patients received patient-controlled morphine analgesia during the postoperative period and consumption was recorded for 24 h. During the PACU period, mean visual analogue scale values were significantly lower in groups 1 and 2 compared to group 3 (P < 0.05. During the postoperative period, morphine consumption was 3.03 ± 2.54, 2.7 ± 2.8, and 5.56 ± 3.12 mg for each group, respectively (P < 0.05. As a side effect, bleeding was observed in groups 1 and 3, nausea and vomiting in all groups, and edema only in group 3. However, no significant differences were detected in any of the parameters analyzed, which also included epigastric pain, constipation/diarrhea and headache. Similar hematological test results were obtained for all groups. Preemptive administration of piroxicam-β-cyclodextrin effectively reduced analgesic consumption, and 40 mg of the drug was more effective than 20 mg piroxicam-β-cyclodextrin without side effects during the postoperative period.

  20. Poly(L-lactide)/branched β-cyclodextrin blends: Thermal, morphological and mechanical properties.

    Science.gov (United States)

    Lizundia, E; Gómez-Galván, F; Pérez-Álvarez, L; León, L M; Vilas, J L

    2016-06-25

    In this work we develop poly(L-lactide)/branched β-cyclodextrin (bβCD) blends in an attempt to obtain new biocompatible and biodegradable materials to be used in the emerging fields of pharmaceutical, biomedicine and food industry. Ionic branched β-cyclodextrin (bβCD) was obtained by polycondensation of the β-CD monomer and it was blended with a commercially available PLLA. Fourier transform infrared spectroscopy (FTIR) has been applied to study the occurring interactions between both partners. Thermal properties of blends have been analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), while the phase structure of the blends was analyzed by scanning electron microscopy (SEM). Finally, dynamic mechanical analysis (DMA) has been used to provide further insights into the features controlling miscibility between PLLA and bβCD. Results show the presence of a single phase irrespectively of the blend composition. Overall, this work opens new perspectives for the development of naturally available materials with tunable functional properties for applications in which cyclodextrins emerge as a new class of promising candidates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Organization of fluorescent cholesterol analogs in lipid bilayers - lessons from cyclodextrin extraction.

    Science.gov (United States)

    Milles, Sigrid; Meyer, Thomas; Scheidt, Holger A; Schwarzer, Roland; Thomas, Lars; Marek, Magdalena; Szente, Lajos; Bittman, Robert; Herrmann, Andreas; Günther Pomorski, Thomas; Huster, Daniel; Müller, Peter

    2013-08-01

    To characterize the structure and dynamics of cholesterol in membranes, fluorescent analogs of the native molecule have widely been employed. The cholesterol content in membranes is in general manipulated by using water-soluble cyclodextrins. Since the interactions between cyclodextrins and fluorescent-labeled cholesterol have not been investigated in detail so far, we have compared the cyclodextrin-mediated membrane extraction of three different fluorescent cholesterol analogs (one bearing a NBD and two bearing BODIPY moieties). Extraction of these analogs was followed by measuring the Förster resonance energy transfer between a rhodamine moiety linked to phosphatidylethanolamine and the labeled cholesterol. The extraction kinetics revealed that the analogs are differently extracted from membranes. We examined the orientation of the analogs within the membrane and their influence on lipid condensation using NMR and EPR spectroscopies. Our data indicate that the extraction of fluorescent sterols from membranes is determined by several parameters, including their impact on lipid order, their hydrophobicity, their intermolecular interactions with surrounding lipids, their orientation within the bilayer, and their affinity with the exogenous acceptor. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Effect of cyclodextrin complexation on the aqueous solubility and solubility/dose ratio of praziquantel.

    Science.gov (United States)

    Maragos, Stratos; Archontaki, Helen; Macheras, Panos; Valsami, Georgia

    2009-01-01

    Praziquantel (PZQ), the primary drug of choice in the treatment of schistosomiasis, is a highly lipophilic drug that possesses high permeability and low aqueous solubility and is, therefore, classified as a Class II drug according to the Biopharmaceutics Classification System (BCS). In this work, beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) were used in order to determine whether increasing the aqueous solubility of a drug by complexation with CDs, a BCS-Class II compound like PZQ could behave as BCS-Class I (highly soluble/highly permeable) drug. Phase solubility and the kneading and lyophilization techniques were used for inclusion complex preparation; solubility was determined by UV spectroscopy. The ability of the water soluble polymer polyvinylpyrolidone (PVP) to increase the complexation and solubilization efficiency of beta-CD and HP-beta-CD for PZQ was examined. Results showed significant improvement of PZQ solubility in the presence of both cyclodextrins but no additional effect in the presence of PVP. The solubility/dose ratios values of PZQ-cyclodextrin complexes calculated considering the low (150 mg) and the high dose (600 mg) of PZQ, used in practice, indicate that PZQ complexation with CDs may result in drug dosage forms that would behave as a BCS-Class I depending on the administered dose.

  3. Capping of Silybin with β-Cyclodextrin Influences its Binding with Bovine Serum Albumin: A Study by Fluorescence Spectroscopy and Molecular Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, Sudha; Sowrirajan, Chandrasekaran; Dhanaraj, Premnath; Enoch, Israel V. M. V. [Karunya Univ., Tamil Nadu (India)

    2014-07-15

    The association of silybin with β-cyclodextrin and its influence on silybin's binding with bovine serum albumin are reported. The stoichiometry, binding constant, and the structure of silybin-β-cyclodextrin inclusion complex are reported. The titrations of silybin with bovine serum albumin in the absence and presence of β-cyclodextrin are carried out and the differences in binding strengths are discussed. Molecular modeling is used to optimize the sites and mode of binding of silybin with bovine serum albumin. Forster resonance energy transfer is calculated and the proximity of interacting molecules is reported in the presence and absence of β-cyclodextrin.

  4. Capping of Silybin with β-Cyclodextrin Influences its Binding with Bovine Serum Albumin: A Study by Fluorescence Spectroscopy and Molecular Modeling

    International Nuclear Information System (INIS)

    Natesan, Sudha; Sowrirajan, Chandrasekaran; Dhanaraj, Premnath; Enoch, Israel V. M. V.

    2014-01-01

    The association of silybin with β-cyclodextrin and its influence on silybin's binding with bovine serum albumin are reported. The stoichiometry, binding constant, and the structure of silybin-β-cyclodextrin inclusion complex are reported. The titrations of silybin with bovine serum albumin in the absence and presence of β-cyclodextrin are carried out and the differences in binding strengths are discussed. Molecular modeling is used to optimize the sites and mode of binding of silybin with bovine serum albumin. Forster resonance energy transfer is calculated and the proximity of interacting molecules is reported in the presence and absence of β-cyclodextrin

  5. Physico-chemical and Biological Evaluation of Flavonols: Fisetin, Quercetin and Kaempferol Alone and Incorporated in beta Cyclodextrins.

    Science.gov (United States)

    Corina, Danciu; Bojin, Florina; Ambrus, Rita; Muntean, Delia; Soica, Codruta; Paunescu, Virgil; Cristea, Mirabela; Pinzaru, Iulia; Dehelean, Cristina

    2017-01-01

    Fisetin,quercetin and kaempferol are among the important representatives of flavonols, biological active phytocomounds, with low water solubility. To evaluate the antimicrobial effect, respectively the antiproliferative and pro apoptotic activity on the B164A5 murine melanoma cell line of pure flavonols and their beta cyclodextrins complexes. Incorporation of fisetin, quercetin and kaempferol in beta cyclodextrins was proved by scanning electron microscopy (SEM), differencial scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). Pure compounds and their complexes were tested for antiproliferative (MTT) and pro-apoptotic activity (Annexin V-PI) on the B164A5 murine melanoma cell line and for the antimicrobial properties (Disk Diffusion Method) on the selected strains. The phytocompounds presented in a different manner in vitro chemopreventive activity against B164A5 murine melanoma cell line and weak antimicrobial effect. The three flavonols: fisetin, quercetin and kaempferol were successfully incorporated in beta-cyclodextrin (BCD) and hydroxylpropyl-beta-cyclodextrin (HPBCD). Incorporation in beta cyclodextrins had a mix effect on the biological activity conducing to decrease, increase or consistent effect compared to pure phytocompound, depending on the screened process and on the chosen combination. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. Colorimetric detection of riboflavin by silver nanoparticles capped with β-cyclodextrin-grafted citrate.

    Science.gov (United States)

    Ma, Qi; Song, Jinping; Zhang, Sufang; Wang, Meifang; Guo, Yong; Dong, Chuan

    2016-12-01

    β-Cyclodextrin-grafted citrate was used for the first time as a stabilizer and reducer to prepare silver nanoparticles (AgNPs). The as-synthesized AgNPs were further characterized by UV-vis absorption spectroscopy, powder X-ray diffraction spectroscopy, and transmission electron microscopy. The results show that the presence of riboflavin caused severe aggregation of the nanoparticles, thereby inducing a colour change from yellow to red. 1 H NMR further verified the formation of non-inclusion complexes between riboflavin and β-cyclodextrin-grafted citrate. Hydrogen bond was considered the main driving force of the interaction between the riboflavin and external rim of β-cyclodextrin. Based on these observations, the as-synthesized AgNPs were utilized to develop a novel colorimetric sensor for riboflavin detection. This colorimetric probe showed excellent selectivity and high sensitivity for riboflavin with a detection limit of 167nM. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Cyclodextrin-PEG conjugate-wrapped magnetic ferrite nanoparticles for enhanced drug loading and release

    Science.gov (United States)

    Enoch, Israel V. M. V.; Ramasamy, Sivaraj; Mohiyuddin, Shanid; Gopinath, Packirisamy; Manoharan, R.

    2018-05-01

    Magnetic nanoparticles are envisaged to overcome the impediments in the methods of targeted drug delivery and hence cure cancer effectively. We report herein, manganese ferrite nanoparticles, coated with β-cyclodextrin-modified polyethylene glycol as a carrier for the drug, camptothecin. The particles are of the size of 100 nm and they show superparamagnetic behaviour. The saturation magnetization does not get diminished on polymer coverage of the nanoparticles. The β-cyclodextrin-polyethylene glycol conjugates are characterized using NMR and mass spectrometric techniques. By coating the magnetic nanoparticles with the cyclodextrin-tethered polymer, the drug-loading capacity is enhanced and the observed release of the drug is slow and sustained. The cell viability of HEK293 and HCT15 cells is evaluated and the cytotoxicity is enhanced when the drug is loaded in the polymer-coated magnetic nanoparticles. The noncovalent-binding based and enhanced drug loading on the nanoparticles and the sustained release make the nanocarrier a promising agent for carrying the payload to the target.

  8. Molecular Modeling and Physicochemical Properties of Supramolecular Complexes of Limonene with α- and β-Cyclodextrins.

    Science.gov (United States)

    Dos Passos Menezes, Paula; Dos Santos, Polliana Barbosa Pereira; Dória, Grace Anne Azevedo; de Sousa, Bruna Maria Hipólito; Serafini, Mairim Russo; Nunes, Paula Santos; Quintans-Júnior, Lucindo José; de Matos, Iara Lisboa; Alves, Péricles Barreto; Bezerra, Daniel Pereira; Mendonça Júnior, Francisco Jaime Bezerra; da Silva, Gabriel Francisco; de Aquino, Thiago Mendonça; de Souza Bento, Edson; Scotti, Marcus Tullius; Scotti, Luciana; de Souza Araujo, Adriano Antunes

    2017-02-01

    This study evaluated three different methods for the formation of an inclusion complex between alpha- and beta-cyclodextrin (α- and β-CD) and limonene (LIM) with the goal of improving the physicochemical properties of limonene. The study samples were prepared through physical mixing (PM), paste complexation (PC), and slurry complexation (SC) methods in the molar ratio of 1:1 (cyclodextrin:limonene). The complexes prepared were evaluated with thermogravimetry/derivate thermogravimetry, infrared spectroscopy, X-ray diffraction, complexation efficiency through gas chromatography/mass spectrometry analyses, molecular modeling, and nuclear magnetic resonance. The results showed that the physical mixing procedure did not produce complexation, but the paste and slurry methods produced inclusion complexes, which demonstrated interactions outside of the cavity of the CDs. However, the paste obtained with β-cyclodextrin did not demonstrate complexation in the gas chromatographic technique because, after extraction, most of the limonene was either surface-adsorbed by β-cyclodextrin or volatilized during the procedure. We conclude that paste complexation and slurry complexation are effective and economic methods to improve the physicochemical character of limonene and could have important applications in pharmacological activities in terms of an increase in solubility.

  9. A water-soluble, mucoadhesive quaternary ammonium chitosan-methyl-β-cyclodextrin conjugate forming inclusion complexes with dexamethasone.

    Science.gov (United States)

    Piras, Anna Maria; Zambito, Ylenia; Burgalassi, Susi; Monti, Daniela; Tampucci, Silvia; Terreni, Eleonora; Fabiano, Angela; Balzano, Federica; Uccello-Barretta, Gloria; Chetoni, Patrizia

    2018-03-30

    The ocular bioavailability of lipophilic drugs, such as dexamethasone, depends on both drug water solubility and mucoadhesion/permeation. Cyclodextrins and chitosan are frequently employed to either improve drug solubility or prolong drug contact onto mucosae, respectively. Although the covalent conjugation of cyclodextrin and chitosan brings to mucoadhesive drug complexes, their water solubility is restricted to acidic pHs. This paper describes a straightforward grafting of methyl-β-cyclodextrin (MCD) on quaternary ammonium chitosan (QA-Ch60), mediated by hexamethylene diisocyanate. The resulting product is a water-soluble chitosan derivative, having a 10-atom long spacer between the quaternized chitosan and the cyclodextrin. The derivative is capable of complexing the model drug dexamethasone and stable complexes were also observed for the lyophilized products. Furthermore, the conjugate preserves the mucoadhesive properties typical of quaternized chitosan and its safety as solubilizing excipient for ophthalmic applications was preliminary assessed by in vitro cytotoxicity evaluations. Taken as a whole, the observed features appear promising for future processing of the developed product into 3D solid forms, such as controlled drug delivery systems, films or drug eluting medical devices.

  10. Effect of pH on the complexation of kaempferol-4'-glucoside with three β-cyclodextrin derivatives: isothermal titration calorimetry and spectroscopy study.

    Science.gov (United States)

    Zheng, Yan; Dong, Li-Na; Liu, Min; Chen, Aiju; Feng, Shangcai; Wang, Bingquan; Sun, Dezhi

    2014-01-08

    The utilization of kaempferol and its glycosides in food and pharmaceutical industries could be improved by the formation of inclusion complexes with cyclodextrins at different pH. This study explores the complexation of kaempferol-4'-glucoside with sulfobutyl ether-β-cyclodextrin (SBE-β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and methylated-β-cyclodextrin (M-β-CD) in phosphate buffer solutions of different pH using isothermal titration calorimetry, UV-vis absorption and proton nuclear magnetic resonance spectroscopy at 298.2 K. Experimental results showed that kaempferol-4'-glucoside binds with the three β- cyclodextrins in the same 1:1 stoichiometry. The rank order of stability constants is SBE-β-CD > HP-β-CD > M-β-CD at the same pH level and pH 6.0 > pH 7.4 > pH 9.0 for the same cyclodextrin. The binding of kaempferol-4'-glucoside with the three β-cyclodextrin derivatives is synergistically driven by enthalpy and entropy at pH 6.0 and enthalpy-driven at pH 7.4 and 9.0. The possible inclusion mode was that in the cavity of β-CD is included the planar benzopyranic-4-one part of the kaempferol-4'-glucoside.

  11. Increased podophyllotoxin production in Podophyllum hexandrum cell suspension cultures after feeding coniferyl alcohol as a β-cyclodextrin complex

    NARCIS (Netherlands)

    Woerdenbag, H.J.; Van Uden, W.; Frijlink, H.W.; Lerk, C.F.; Pras, N.; Malingre, T.M.

    1990-01-01

    Cell suspension cultures, derived from roots of Podophyllum hexandrum Royle (Berberidaceae), accumulate podophyllotoxin. In this study the use of β-cyclodextrin in feeding the poorly water-soluble precursor coniferyl alcohol to these cultures is described. By complexation with β-cyclodextrin, a

  12. Increased podophyllotoxin production in Podophyllum hexandrum cell suspension cultures after feeding coniferyl alcohol as a β-cyclodextrin complex

    NARCIS (Netherlands)

    Woerdenbag, H J; van Uden, W; Frijlink, H W; Lerk, C F; Pras, N; Malingré, T M

    Cell suspension cultures, derived from roots of Podophyllum hexandrum Royle (Berberidaceae), accumulate podophyllotoxin. In this study the use of β-cyclodextrin in feeding the poorly water-soluble precursor coniferyl alcohol to these cultures is described. By complexation with β-cyclodextrin, a

  13. Investigation of interaction of vanillin with Alpha, Beta and Gamma-cyclodextrin as drug delivery carriers: brief report

    Directory of Open Access Journals (Sweden)

    Batoolalsadat Mousavi Fard

    2015-05-01

    Methods: All theoretical calculations were performed on a Intel® Core™ i5 Processors computer at Kerman University using Gaussian 09 program package (Gaussian, Inc., Wallingford, USA in a three month period (February 2014 to May 2014. Starting geometries were generated employing GaussView software, version 5 (Gaussian, Inc., Wallingford, USA and then the resulting coordinates were optimized using density functional theory (DFT calculations. The natural bond orbital method (NBO program, under Gaussian 09 program package was carried out to study charge transfer energy associated with the intermolecular interactions. The quantum theory of atoms in molecules was applied for DFT results to get insight in the nature of interaction existing in the investigated systems. The calculations were carried out with AIM2000 program and AIMAll 14.10.27 package (Todd A. Keith, TK Gristmill software, Overland Park KS, USA to find and characterize bond critical points. Results: The vanillin molecule is adsorbed on the surface of carriers by hydrogen bonding between its oxygen atom and hydrogen atoms of cyclodextrin. The hydrogen of -OH group on the cyclodextrin can form hydrogen bond to the oxygen atom of carbonyl group of vanillin molecule. This study indicates a decrease of total energy with increasing surface of cyclodextrin. So gamma-cyclodextrin and its complex with the maximum surface in between carriers have the highest stabilities. The gamma-cyclodextrin shows the strongest interaction with vanillin. In all complexes of vanillin-cyclodextrin, the direction of charge transfer is from drug to carrier. Conclusion: Due to the high solubility of gamma-cyclodxtrin and its stronger interaction with the molecule vanillin, it can be the best option as drug carrier.

  14. Effect of Cyclodextrin Complexation on the Aqueous Solubility and Solubility/Dose Ratio of Praziquantel

    OpenAIRE

    Maragos, Stratos; Archontaki, Helen; Macheras, Panos; Valsami, Georgia

    2009-01-01

    Praziquantel (PZQ), the primary drug of choice in the treatment of schistosomiasis, is a highly lipophilic drug that possesses high permeability and low aqueous solubility and is, therefore, classified as a Class II drug according to the Biopharmaceutics Classification System (BCS). In this work, β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) were used in order to determine whether increasing the aqueous solubility of a drug by complexation with CDs, a BCS-Class II compound ...

  15. Biodegradable films containing {alpha}-tocopherol/{beta}-cyclodextrin complex; Filmes biodegradaveis contendo {alpha}-tocoferol complexado em {beta}-ciclodextrina

    Energy Technology Data Exchange (ETDEWEB)

    Motta, Caroline; Martelli, Silvia M.; Soldi, Valdir, E-mail: vsoldi@qmc.ufsc.br [Lab. de Materiais Polimericos (POLIMAT), Dept. de Quimica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil); Barreto, Pedro L.M. [Lab. de Reologia (REOLAB), Dept. de Ciencia e Tecnologia de Alimentos, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil)

    2011-07-01

    The growing environmental concern about pollution and the need to reduce dependence of plastic industry in relation to non-renewable resources has increased the interest of both researchers and industry in the use of biopolymers. In this work {beta}-cyclodextrin/{alpha}-tocopherol complexes were prepared and characterized. In order to obtain polymeric active biofilms, the {beta}-cyclodextrin/{alpha}-tocopherol complex was incorporated into a polymeric matrix of carboxymethylcellulose. The {beta}-cyclodextrin/{alpha}-tocopherol complex was characterized through of X-ray diffraction and thermogravimetric analysis. The physicochemical properties of the films incorporated with the complex were evaluated through mechanical and colorimetric analysis and moisture sorption isotherm. (author)

  16. Fluorescence spectroscopic investigation of the interaction of citrinin with native and chemically modified cyclodextrins

    Energy Technology Data Exchange (ETDEWEB)

    Poór, Miklós, E-mail: poor.miklos@pte.hu [Department of Pharmacology and Pharmacotherapy, Toxicology Section, University of Pécs, Szigeti út 12, Pécs H-7624 (Hungary); Matisz, Gergely; Kunsági-Máté, Sándor [Department of General and Physical Chemistry, University of Pécs, Ifjúság útja 6, Pécs H-7624 (Hungary); János Szentágothai Research Center, Ifjúság útja 20, Pécs H-7624 (Hungary); Derdák, Diána [Department of General and Physical Chemistry, University of Pécs, Ifjúság útja 6, Pécs H-7624 (Hungary); Szente, Lajos [CycloLab Cyclodextrin Research & Development Laboratory Ltd., Illatos út 7, Budapest H-1097 (Hungary); and others

    2016-04-15

    Citrinin (CIT) is a nephrotoxic mycotoxin produced by several Aspergillus, Penicillium and Monascus species. CIT is unavoidable contaminant of different foods and drinks due to its wide occurrence and high thermal stability. For this reason, development of new, more sensitive analytical methods and decontamination strategies has high importance. In our study, the complex formation of CIT with native and chemically modified cyclodextrins was investigated using fluorescence spectroscopy. Furthermore, thermodynamic and molecular modeling studies were also performed for the deeper understanding of these host-guest interactions. Our results show that among the tested compounds methylated β-cyclodextrins form the most stable complexes with CIT and these derivatives cause the highest fluorescence enhancement of CIT as well. These observations recommend that some of the chemically modified derivatives show more favourable properties than the native cyclodextrin, and suggesting more promising analytical applicability and higher affinity as potential toxin binders.

  17. Cyclodextrin dimers as receptor molecules for steroid sensors

    NARCIS (Netherlands)

    de Jong, M.R.; Engbersen, Johannes F.J.; Huskens, Jurriaan; Reinhoudt, David

    2000-01-01

    The dansyl-modified dimer 9 complexes strongly with the steroidal bile salts. Relative to native -cyclodextrin, the binding of cholate (1 a) and deoxycholate (1 b) salts is especially enhanced. These steroids bind exclusively in a 1:1 fashion. For other bile salts (1 c-1 e) both 1:1 and 1:2

  18. Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

    International Nuclear Information System (INIS)

    Zhou, Jie; Wang, Yiying; Liu, Yun; Tang, Jian; Tang, Weihua

    2015-01-01

    Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6 A -4-hydroxyethyl-1,2,3-triazolyl-6 C -3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study

  19. Methoxypropylamino β-cyclodextrin clicked AC regioisomer for enantioseparations in capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jie; Wang, Yiying; Liu, Yun; Tang, Jian; Tang, Weihua, E-mail: whtang@mail.njust.edu.cn

    2015-04-08

    Highlights: In this paper, we demonstrate: • The click synthesis of a AC regioisomer cationic cyclodextrin (CD) as chiral selector. • The good enantioselectivities (chiral resolution over 5) for acidic racemates. • The strong chiral recognition of new CD by NMR study. • Baseline enantioseparation of some acidic racemates at CD of 0.5 mM. - Abstract: In this work, a novel methoxypropylamino β-cyclodextrin (β-CD) clicked AC regioisomer, 6{sup A}-4-hydroxyethyl-1,2,3-triazolyl-6{sup C}-3-methoxypropylamino β-cyclodextrin (HETz-MPrAMCD), was synthesized via nucleophilic addition and click chemistry. The chiral separation ability of this AC regioisomer cationic CD was evaluated toward 7 ampholytic and 13 acidic racemates by capillary electrophoresis. Dependence of enantioselectivity and resolution on buffer pH (5.5–8.0) and chiral selector concentration (0.5–7.5 mM) was investigated. Enantioselectivities (α ≥ 1.05) could be achieved for most analytes under optimal conditions except dansyl-DL-noreleucine and dansyl-DL-serine. The highest resolutions for 2-chloromandelic acid p-hydroxymandelic acid were 15.6 and 9.7 respectively. The inclusion complexation between HETz-MPrAMCD and each 3-phenyllactic acid enantiomer was also revealed with nuclear magnetic resonance study.

  20. Investigating the inclusion properties of aromatic amino acids complexing beta-cyclodextrins in model peptides.

    Science.gov (United States)

    Caso, Jolanda Valentina; Russo, Luigi; Palmieri, Maddalena; Malgieri, Gaetano; Galdiero, Stefania; Falanga, Annarita; Isernia, Carla; Iacovino, Rosa

    2015-10-01

    Cyclodextrins are commonly used as complexing agents in biological, pharmaceutical, and industrial applications since they have an effect on protein thermal and proteolytic stability, refolding yields, solubility, and taste masking. β-cyclodextrins (β-CD), because of their cavity size are a perfectly suited complexing agent for many common guest moieties. In the case of peptide-cyclodextrin and protein-cyclodextrin host-guest complexes the aromatic amino acids are reported to be the principal responsible of the interaction. For these reasons, we have investigated the inclusion properties of nine designed tripeptides, obtained permuting the position of two L-alanines (Ala, A) with that of one L-tryptophan (Trp, W), L-phenylalanine (Phe, F), or L-tyrosine (Tyr, Y), respectively. Interestingly, the position of the aromatic side-chain in the sequence appears to modulate the β-CD:peptide binding constants, determined via UV-Vis and NMR spectroscopy, which in turn assumes values higher than those reported for the single amino acid. The tripeptides containing a tyrosine showed the highest binding constants, with the central position in the Ac-AYA-NH2 peptide becoming the most favorite for the interaction. A combined NMR and Molecular Docking approach permitted to build detailed complex models, highlighting the stabilizing interactions of the neighboring amino acids backbone atoms with the upper rim of the β-CD.

  1. Nuclear magnetic resonance study of naproxen and ibuprofen interaction with β - cyclodextrin in solution

    International Nuclear Information System (INIS)

    Bogdan, M.; Farcas, S.I.; Bojita, M.

    1999-01-01

    Modern biomedical research leads to revealing insights into the molecular activity of many therapeutic molecules. An interesting activity at the organ or cellular level, however, is not sufficient to turn a molecule into an usable drug. Problems such as limited solubility or stability can make impossible to transpose interesting in vitro properties of an experimental compound to an in vivo situation. Various physico - chemical methods have been used to improve aqueous solubility of poorly soluble drugs and to increase the life of unstable drugs, such as adjustment of pH of the aqueous solution, the complexation of drugs with various cyclodextrins and the formation of gels or emulsions. In this paper, we report a 1 H NMR study of the complex formed between naproxen and ibuprofen with β - cyclodextrin in aqueous medium. Our results confirm that inclusion occurs. Analysis of our data by the continuous variation method shows that the complexes have 1 : 1 stoichiometry. The association constants for the 1 : 1 complexes were calculated at different temperatures by non - linear least squares regression analysis of the observed changes in the chemical shifts of the drugs and β - cyclodextrin 1 H NMR lines as a function of β - cyclodextrin concentration. Thermodynamic parameters were obtained by using the temperature dependence of the association constants. Finally, based on the experimentally obtained data, the most probable structure of the investigated complexes is discussed. (authors)

  2. Electrospun Fibers of Cyclodextrins and Poly(cyclodextrins

    Directory of Open Access Journals (Sweden)

    Alejandro Costoya

    2017-02-01

    Full Text Available Cyclodextrins (CDs can endow electrospun fibers with outstanding performance characteristics that rely on their ability to form inclusion complexes. The inclusion complexes can be blended with electrospinnable polymers or used themselves as main components of electrospun nanofibers. In general, the presence of CDs promotes drug release in aqueous media, but they may also play other roles such as protection of the drug against adverse agents during and after electrospinning, and retention of volatile fragrances or therapeutic agents to be slowly released to the environment. Moreover, fibers prepared with empty CDs appear particularly suitable for affinity separation. The interest for CD-containing nanofibers is exponentially increasing as the scope of applications is widening. The aim of this review is to provide an overview of the state-of-the-art on CD-containing electrospun mats. The information has been classified into three main sections: (i fibers of mixtures of CDs and polymers, including polypseudorotaxanes and post-functionalization; (ii fibers of polymer-free CDs; and (iii fibers of CD-based polymers (namely, polycyclodextrins. Processing conditions and applications are analyzed, including possibilities of development of stimuli-responsive fibers.

  3. Cellular Interaction and Tumoral Penetration Properties of Cyclodextrin Nanoparticles on 3D Breast Tumor Model

    Directory of Open Access Journals (Sweden)

    Gamze Varan

    2018-01-01

    Full Text Available Amphiphilic cyclodextrins are biocompatible oligosaccharides that can be used for drug delivery especially for the delivery of drugs with solubility problems thanks to their unique molecular structures. In this paper, Paclitaxel was used as a model anticancer drug to determine the inclusion complex properties of amphiphilic cyclodextrins with different surface charge. Paclitaxel-loaded cyclodextrin nanoparticles were characterized in terms of mean particle diameter, zeta potential, encapsulation efficacy, drug release profile and cell culture studies. It was determined that the nanoparticles prepared from the inclusion complex according to characterization studies have a longer release profile than the conventionally prepared nanoparticles. In order to mimic the tumor microenvironment, breast cancer cells and healthy fibroblast cells were used in 3-dimensional (3D cell culture studies. It was determined that the activities of nanoparticles prepared by conventional methods behave differently in 2-dimensional (2D and 3D cell cultures. In addition, it was observed that the nanoparticles prepared from the inclusion complex have a stronger anti-tumoral activity in the 3D multicellular tumor model than the drug solution. Furthermore, polycationic amphiphilic cyclodextrin nanoparticles can diffuse and penetrate through multilayer cells in a 3D tumor model, which is crucial for an eventual antitumor effect.

  4. Thermodynamics of the interaction between antihistamines with native and hydroxypropyl-cyclodextrin derivatives in aqueous solutions

    International Nuclear Information System (INIS)

    Alvarez-Lopez, Enrique; Perez-Casas, Silvia

    2013-01-01

    Highlights: • The complexes formation between cyclodextrins and pheniramines were studied by ITC. • In all the cases, the process is enthalpy driven. • The interactions between cyclodextrins and pheniramines are discussed. -- Abstract: The interactions of native and hydroxypropyl-cyclodextrin derivatives with pheniramine, (±)-brompheniramine, (+)-brompheniramine, (±)-chlorpheniramine, (+)-chlorpheniramine, carbinoxamine maleate salts and doxylamine succinate salt have been studied by isothermal titration calorimetry at T = 298.15 K in aqueous solution. The enthalpies and association constants for the complex formation were obtained, from which the Gibbs energy and entropy changes were derived. The thermodynamic parameters corresponding to the transfer process of the guest from the native to the modified CD are also calculated. The results show that the hydrophobic interactions are important in this process, but the size of the guest and the nature of the substituent are also of some importance

  5. Enhanced accumulation of phytosterols and phenolic compounds in cyclodextrin-elicited cell suspension culture of Daucus carota.

    Science.gov (United States)

    Miras-Moreno, Begoña; Almagro, Lorena; Pedreño, M A; Sabater-Jara, Ana Belén

    2016-09-01

    In this work, suspension-cultured cells of Daucus carota were used to evaluate the effect of β-cyclodextrins on the production of isoprenoid and phenolic compounds. The results showed that the phytosterols and phenolic compounds were accumulated in the extracellular medium (15100μgL(-1) and 477.46μgL(-1), respectively) in the presence of cyclodextrins. Unlike the phytosterol and phenolic compound content, β-carotene (1138.03μgL(-1)), lutein (25949.54μgL(-1)) and α-tocopherol (8063.82μgL(-1)) chlorophyll a (1625.13μgL(-1)) and b (9.958 (9958.33μgL(-1)) were mainly accumulated inside the cells. Therefore, cyclodextrins were able to induce the cytosolic mevalonate pathway, increasing the biosynthesis of phytosterols and phenolic compounds, and accumulate them outside the cells. However, in the absence of these cyclic oligosaccharidic elicitors, carrot cells mainly accumulated carotenoids through the methylerythritol 4-phosphate pathway. Therefore, the use of cyclodextrins would allow the extracellular accumulation of both phytosterols and phenolic compounds by diverting the carbon flux towards the cytosolic mevalonate/phenylpropanoid pathway. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Egg yolk and glycerol requirements for freezing boar spermatozoa treated with methyl β-cyclodextrin or cholesterol-loaded cyclodextrin.

    Science.gov (United States)

    Blanch, Eva; Tomás, Cristina; Hernández, Marta; Roca, Jordi; Martínez, Emilio A; Vázquez, Juan M; Mocé, Eva

    2014-04-24

    Egg yolk (EY) and glycerol are common constituents of extenders used for sperm cryopreservation. It has been demonstrated that using cholesterol-loaded cyclodextrins (CLC) improves sperm cryosurvival in several species. However, standard freezing extenders might not be the most appropriate for CLC-treated sperm. This study evaluated the EY and glycerol requirements for freezing CLC-treated boar spermatozoa. Semen samples from 34 ejaculates coming from 4 boars were used. Each ejaculate was split into three aliquots: one was used untreated (control), and the other two were treated with 1 mg of CLC or methyl-β-cyclodextrin/120 × 10(6) sperm for 15 min at 22 C prior to cryopreservation. Our results indicated that reducing the concentration of EY was detrimental for sperm viability after thawing (31.57 ± 2 vs. 19.89% ± 2 for 20 and 10% EY, respectively; P semen treated with CLC. On the other hand, it was observed that the traditional concentration of glycerol (3%) was not the appropriate for freezing CLC-treated sperm (61.10 ± 3 vs. 47.87% ± 3 viable sperm for control and CLC-treated sperm, respectively; P extenders for CLC-treated sperm. Nevertheless, additional studies will be needed to evaluate alternative cryoprotectants and to determine the effect of high glycerol concentrations on sperm functionality.

  7. Synthesis and characterization of thiolated carboxymethyl chitosan-graft-cyclodextrin nanoparticles as a drug delivery vehicle for albendazole.

    Science.gov (United States)

    Alamdarnejad, Ghazaleh; Sharif, Alireza; Taranejoo, Shahrouz; Janmaleki, Mohsen; Kalaee, Mohammad Reza; Dadgar, Mohsen; Khakpour, Mazyar

    2013-08-01

    A new strategy for the synthesis of thiolated carboxymethyl chitosan-g-cyclodextrin nanoparticles by an ionic-gelation method is presented. The synthetic approach was based on the utilization of 1,6-hexamethylene diisocyanate during cyclodextrin grafting onto carboxymethyl chitosan. The use of the 1,6-hexamethylene diisocyanate resulted in reactions between cyclodextrin and active sites at the C6-position of chitosan, and preserved amino groups of chitosan for subsequent reactions with thioglycolic acid, as the thiolating agent, and tripolyphosphate, as the gelling counterion. Various methods such as scanning electron microscopy, rheology and in vitro release studies were employed to exhibit significant features of the nanoparticles for mucosal albendazole delivery applications. It was found that the thiolated carboxymethyl chitosan-g-cyclodextrin nanoparticles prepared using an aqueous solution containing 1 wt% of tripolyphosphate and having 115.65 (μmol/g polymer) of grafted thiol groups show both the highest mucoadhesive properties and the highest albendazole entrapment efficiency. The latter was confirmed theoretically by calculating the enthalpy of mixing of albendazole in the above thiolated chitosan polymer.

  8. A β-cyclodextrin based binary dopant for polyaniline: Structural, thermal, electrical, and sensing performance

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Tanushree; Mishra, Satyendra [University Institute of Chemical Technology, North Maharashtra University, Jalgaon 425001, Maharashtra (India); Shimpi, Navinchandra G., E-mail: navin_shimpi@rediffmail.com [Department of Chemistry, University of Mumbai, Kalina, Mumbai 400098, Maharashtra (India)

    2017-06-15

    Highlights: • A binary dopant based on β-cyclodextrin has been proposed for PANI. • The binary dopant provided long term stability to electrically conducting PANI. • The β-cyclodextrin based binary dopant rendered PANI sensitive towards CO at RT. - Abstract: The effect of hydrochloric acid/β-cyclodextrin (HCl/β-CD) binary dopant on the morphological, thermal, electrical, and sensing properties of PANI was investigated and compared with those of the conventionally doped PANI. The PANI samples were characterized using FTIR, UV–Vis, {sup 1}H NMR, and FESEM. Significant changes were observed in the structural, thermal, and electrical character of PANI doped with the HCl/β-CD binary dopant. A higher doping level was obtained for the PANI-binary dopant system, as observed from its {sup 1}H NMR spectra. Moreover, the binary dopant imparted long-term stability to the sensor in its conductive form. In addition, the PANI-binary dopant system exhibited a significantly high gas response towards carbon monoxide gas at room temperature.

  9. Cyclodextrin Reduces Cholesterol Crystal-Induced Inflammation by Modulating Complement Activation

    DEFF Research Database (Denmark)

    Bakke, Siril S; Aune, Marie H; Niyonzima, Nathalie

    2017-01-01

    Cholesterol crystals (CC) are abundant in atherosclerotic plaques and promote inflammatory responses via the complement system and inflammasome activation. Cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (BCD) is a compound that solubilizes lipophilic substances. Recently we have shown...

  10. .beta.-Cyclodextrin-epichlorohydrin polymer/graphene oxide nanocomposite: preparation and characterization

    Czech Academy of Sciences Publication Activity Database

    Heydari, A.; Sheibani, H.; Hronský, V.; Janigová, I.; Šlouf, Miroslav; Šiffalovič, P.; Chodák, I.

    2018-01-01

    Roč. 72, č. 5 (2018), s. 1299-1313 ISSN 0366-6352 Institutional support: RVO:61389013 Keywords : beta-cyclodextrin * graphene oxide * hydrogels Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.258, year: 2016

  11. Modulation of Cyclodextrin Particle Amphiphilic Properties to Stabilize Pickering Emulsion.

    Science.gov (United States)

    Xi, Yongkang; Luo, Zhigang; Lu, Xuanxuan; Peng, Xichun

    2018-01-10

    Cyclodextrins have been proven to form complexes with linear oil molecules and stabilize emulsions. Amphiphilic properties of cyclodextrin particles were modulated through esterification reaction between β-cyclodextrin (β-CD) and octadecenyl succinic anhydride (ODSA) under alkaline conditions. ODS-β-CD particles with degree of substitution (DS) of 0.003, 0.011, and 0.019 were obtained. The introduced hydrophobic long chain that was linked within β-CD cavity led to the change of ODS-β-CD in terms of morphological structure, surface charge density, size, and contact angle, upon which the properties and stability of the emulsions stabilized by ODS-β-CD were highly dependent. The average diameter of ODS-β-CD particles ranged from 449 to 1484 nm. With the DS increased from 0.003 to 0.019, the contact angle and absolute zeta potential value of these ODS-β-CD particles improved from 25.7° to 47.3° and 48.1 to 62.8 mV, respectively. The cage structure of β-CD crystals was transformed to channel structure, then further to amorphous structure after introduction of the octadecenyl succinylation chain. ODS-β-CD particles exhibited higher emulsifying ability compared to β-CD. The resulting Pickering emulsions formed by ODS-β-CD particles were more stable during storage. This study investigates the ability of these ODS-β-CD particles to stabilize oil-in-water emulsions with respect to their amphiphilic character and structural properties.

  12. Controlled Release of Indomethacin from Smart Starch-Based Hydrogels Prepared Acrylic Acid and b-Cyclodextrin as a Nanocarrier

    Directory of Open Access Journals (Sweden)

    Hossein Ghasemzadeh Mohammadi

    2017-01-01

    Full Text Available Controlled release of drugs can reduce the undesired effects of drug level fluctuations, and diminish the side effects as well as improve the therapeutic outcome of the drugs. In recent year, the scope of the drug delivery systems has been greatly expanded by the development of various hydrogels. The present work has focused on the design of a pH sensitive drug delivery system (DDS based on starch, acrylic acid (AA and β-cyclodextrins for controlled delivery of indomethacin. The hydrogels were prepared via graft polymerization of acrylic acid (AA onto starch and β-cyclodextrins backbones by a free radical polymerization technique. Cyclodextrins are able to form water-soluble complexes with many lipophilic water-insoluble drugs. In aqueous solutions, the drug molecules located in the central cavity of the cyclodextrin are in a dynamic equilibrium with free drug molecules. The interaction of drug with the polymer was evidenced by FTIR spectroscopy and thermal gravimetric analysis (TGA. The morphology of the samples was examined by scanning electron microscopy (SEM. The results showed that the hydrogels have good porosity and provided high surface area for the loading and release of drugs. Drug release behavior was carried out at physiological conditions of phosphate buffer, pH 8. In basic pH (like the intestine medium the hydrogels released the indomethacin, but in acidic pH (like the stomach medium there was no tendency to drug release. By increasing the amount of cyclodextrin, the rate of drug loading and release increased due to the dynamic equilibrium and interaction between the loaded drug and the cyclodextrin. This study has demonstrated that the hydrogel matrices are potentially suitable for controlled-release systems.

  13. Mannose-decorated cyclodextrin vesicles: The interplay of multivalency and surface density in lectin–carbohydrate recognition

    Directory of Open Access Journals (Sweden)

    Ulrike Kauscher

    2012-09-01

    Full Text Available Cyclodextrin vesicles are versatile models for biological cell membranes since they provide a bilayer membrane that can easily be modified by host–guest interactions with functional guest molecules. In this article, we investigate the multivalent interaction of the lectin concanavalin A (ConA with cyclodextrin vesicles decorated with mannose–adamantane conjugates with one, two or three adamantane units as well as one or two mannose units. The carbohydrate–lectin interaction in this artificial, self-assembled glycocalyx was monitored in an agglutination assay by the increase of optical density at 400 nm. It was found that there is a close relation between the carbohydrate density at the cyclodextrin vesicle surface and the multivalent interaction with ConA, and the most efficient interaction (i.e., fastest agglutination at lowest concentration was observed for mannose–adamantane conjugates, in which both the cyclodextrin–adamantane and the lectin–mannose interaction is inherently multivalent.

  14. Study on the complexation of isoquercitrin with β-cyclodextrin and its derivatives by spectroscopy

    International Nuclear Information System (INIS)

    Wang Yunlong; Qiao Xiaona; Li Wenchao; Zhou Yehong; Jiao Yong; Yang Cheng; Dong Chuan; Inoue, Yoshihisa; Shuang, Shaomin

    2009-01-01

    The inclusion complexes of isoquercitrin (IQ) with cyclodextrins (CDs) including β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) and dimethyl-β-cyclodextrin (DM-β-CD) have been investigated using the methods of steady-state fluorescence, UV-vis absorption and induced circular dichroism. The stoichiometric ratio of the three complexes was found to be 1:1 and the stability constants (K) were estimated from spectrofluorometric titrations, as well as the thermodynamic parameters. Maximum inclusion ability was measured in the case of DM-β-CD due to the increased hydrophobicity of the host cavity, followed by HP-β-CD and β-CD. The effect of pH on the complexation process was also quantitatively assessed. IQ exists in different molecular forms depending on pH and β-CDs were most suitable for inclusion of the neutral form of IQ. The phase-solubility diagrams obtained with β-CD, HP-β-CD and DM-β-CD were all classical A L type. And DM-β-CD provided the best solubility enhancement, 12.3-fold increase compared to 2.8- and 7.5-fold increase for β-CD and HP-β-CD. The apparent stability constants obtained from the solubility data at 25 deg. C were comparable with those obtained from the fluorescence assays. Moreover, 1 H NMR was carried out, which revealed that the IQ favorably inserted into the inner cavity from the chromone part instead of the phenyl part, which was in agreement with molecular modeling studies.

  15. Spectroscopic investigation of the structures of dialkyl tartrates and their cyclodextrin complexes.

    Science.gov (United States)

    Zhang, Peng; Polavarapu, Prasad L

    2007-02-08

    Structures of three dialkyl tartrates, namely, dimethyl tartrate, diethyl tartrate, and diisopropyl tartrate, in CCl4, dimethyl sulfoxide (DMSO)/DMSO-d6, and H2O/D2O solvents have been investigated using vibrational absorption (VA), vibrational circular dichroism (VCD), and optical rotatory dispersion (ORD). VA, VCD, and ORD spectra are found to be dependent on the solvent used. Density functional theory (DFT) calculations are used to interpret the experimental data in CCl4 and DMSO. The trans-COOR conformer with hydrogen bonding between the OH group and the C=O group attached to the same chiral carbon is dominant for dialkyl tartrates both in vacuum and in CCl4. The experimental VA, VCD, and ORD data of dialkyl-D-tartrates in CCl4 correlated well with those predicted for dimethyl-(S,S)-tartrate molecule as both isolated and solvated in CCl4. In DMSO solvent, dialkyl tartrate molecules favor formation of intermolecular hydrogen bonding with DMSO molecules. Clusters of dimethyl-(S,S)-tartrate, with one molecule of dimethyl-(S,S)-tartrate hydrogen bonded to two DMSO molecules, are used for the DFT calculations. A trans-COOR cluster and a trans-H cluster are needed to obtain a reasonable agreement between the predicted and experimental data of dimethyl tartrate in DMSO solvent. VA, VCD, and optical rotations are also measured for dialkyl tartrate-cyclodextrin complexes. It is noted that these properties are barely affected by complexation of dialkyl tartrates with cyclodextrins, indicating weak interaction between tartrates and cyclodextrin. Binding constants of alpha-CD and beta-CD with diethyl L-tartrate in both H2O and DMSO have been determined using isothermal titration calorimetry technique. The smaller binding constants (less than 100) confirmed the weak interaction between tartrates and cyclodextrin in the solution state.

  16. Synthesis of magnetite nanoparticles-β-cyclodextrin complex

    International Nuclear Information System (INIS)

    Cobos Cruz, L.A.; Martinez Perez, C.A.; Monreal Romero, H.A.; Garcia Casillas, P.E.

    2008-01-01

    In this work, the synthesis and characterization of a magnetite (M) and β-cyclodextrin (CD) complex is presented. The chemical bonding between the magnetite and CD was studied as evidence of host-guest interaction; therefore the CD works like a reactor with the magnetite inside of it, as consequence the growth of the particle is restricted by the electrostatic interaction of M-CD complex. The particle size of the magnetite-cyclodextrin complex (M-CD) decreased 79.1% with 0.5% of CD. The average particle size of the M-CD complex was 10 nm. The saturation magnetization (σ s ) and intrinsic coercivity (H c ) increased 10% and 20%, respectively. In order to understand how the the CD affects the results obtained, the second derivate of remission function was obtained from the ultraviolet-visible spectra (UV-vis). Fourier transform infrared spectroscopy (FTIR) was used to elucidate the interaction between the magnetite and CD. The thermal analysis was measured by thermogravimetric and differential thermal analysis (TGA-DTA). The magnetic properties, intrinsic coercivity (H c ) and the saturation magnetization were determined by vibrating sample magnetometry (VSM); the size and shape of nanoparticles were determined by scanning electron microscopy (SEM). The identification of phases was made by X-ray diffraction

  17. Towards allosteric receptors – synthesis of β-cyclodextrin-functionalised 2,2’-bipyridines and their metal complexes

    Directory of Open Access Journals (Sweden)

    Christopher Kremer

    2014-04-01

    Full Text Available Herein, we present three new 2,2’-bipyridines that carry two β-cyclodextrin moieties in different substitution patterns. When coordinated by zinc(II or copper(I ions (or their complexes, these compounds undergo conformational changes and switch between “open” and “closed” forms and thereby bringing together or separating the cyclodextrin moieties from each other.

  18. Structure and thermal decomposition of sulfated β-cyclodextrin intercalated in a layered double hydroxide

    International Nuclear Information System (INIS)

    Wang Ji; Wei Min; Rao Guoying; Evans, D.G.; Duan Xue

    2004-01-01

    The sodium salt of hexasulfated β-cyclodextrin has been synthesized and intercalated into a magnesium-aluminum layered double hydroxide by ion exchange. The structure, composition and thermal decomposition behavior of the intercalated material have been studied by variable temperature X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma emission spectroscopy (ICP), and thermal analysis (TG-DTA) and a model for the structure has been proposed. The thermal stability of the intercalated sulfated β-cyclodextrin is significantly enhanced compared with the pure form before intercalation

  19. Structure and thermal decomposition of sulfated β-cyclodextrin intercalated in a layered double hydroxide

    Science.gov (United States)

    Wang, Ji; Wei, Min; Rao, Guoying; Evans, David G.; Duan, Xue

    2004-01-01

    The sodium salt of hexasulfated β-cyclodextrin has been synthesized and intercalated into a magnesium-aluminum layered double hydroxide by ion exchange. The structure, composition and thermal decomposition behavior of the intercalated material have been studied by variable temperature X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma emission spectroscopy (ICP), and thermal analysis (TG-DTA) and a model for the structure has been proposed. The thermal stability of the intercalated sulfated β-cyclodextrin is significantly enhanced compared with the pure form before intercalation.

  20. Comparative In Vitro Controlled Release Studies on the Chronobiotic Hormone Melatonin from Cyclodextrins-Containing Matrices and Cyclodextrin: Melatonin Complexes.

    Science.gov (United States)

    Vlachou, Marilena; Papamichael, Marianna; Siamidi, Angeliki; Fragouli, Irene; Afroudakis, Pandelis A; Kompogennitaki, Rodanthi; Dotsikas, Yannis

    2017-07-28

    A series of hydrophilic matrix tablets was prepared and tested with respect to their ability to release the hormone melatonin in a controlled manner, in order to alleviate sleep onset and sleep maintenance dysfunctions. Besides the active ingredient, the tablets were comprised of combinations of the following: HPMC K 15M, low viscosity sodium alginate, microcrystalline cellulose (Avicel PH 102), magnesium stearate, and the cyclodextrins, α-CD, β-CD, γ-CD, HP-β-CD, sulfated β-CD, HP-α-CD and HP-γ-CD, and MLT (guest):CD (host) complexes of the above cyclodextrins, in 1:1 ratio. The controlled release studies were conducted in two aqueous dissolution media at pH 1.2 and 7.4. The stoichiometry of the formed complexes was examined by applying the continuous variation method (Job plot), while the stability constants were calculated by monitoring the spectrophotometric properties of free and CD-encapsulated melatonin (UV-Vis). Host-guest interactions were studied by Nuclear Magnetic Resonance (NMR) spectroscopy. The dissolution data suggest that melatonin is released faster from the MLT:CD complexes than from the rest matrix systems. This enhancement in the dissolution rate and the % release of melatonin from the complexes is due to the increased solubility of the MLT:CD complexes.

  1. Inclusion Complexes of Copaiba (Copaifera multijuga Hayne Oleoresin and Cyclodextrins: Physicochemical Characterization and Anti-Inflammatory Activity

    Directory of Open Access Journals (Sweden)

    Jonas Gabriel de Oliveira Pinheiro

    2017-11-01

    Full Text Available Complexation with cyclodextrins (CDs is a technique that has been extensively used to increase the aqueous solubility of oils and improve their stability. In addition, this technique has been used to convert oils into solid materials. This work aims to develop inclusion complexes of Copaifera multijuga oleoresin (CMO, which presents anti-inflammatory activity, with β-cyclodextrin (β-CD and hydroxypropyl-β-cyclodextrin (HP-β-CD by kneading (KND and slurry (SL methods. Physicochemical characterization was performed to verify the occurrence of interactions between CMO and the cyclodextrins. Carrageenan-induced hind paw edema in mice was carried out to evaluate the anti-inflammatory activity of CMO alone as well as complexed with CDs. Physicochemical characterization confirmed the formation of inclusion complex of CMO with both β-CD and HP-β-CD by KND and SL methods. Carrageenan-induced paw edema test showed that the anti-inflammatory activity of CMO was maintained after complexation with β-CD and HP-β-CD, where they were able to decrease the levels of nitrite and myeloperoxidase. In conclusion, this study showed that it is possible to produce inclusion complexes of CMO with CDs by KND and SL methods without any change in CMO’s anti-inflammatory activity.

  2. Modification of polyethylene films by radiation grafting of glycidyl methacrylate and immobilization of {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Nava-Ortiz, C.A.B. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Burillo, G. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)], E-mail: burillo@nucleares.unam.mx; Bucio, E. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, C. [Departamento de Farmacia y Tecnologia Farmaceutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2009-01-15

    Glycidyl methacrylate was grafted onto polyethylene films using a preirradiation method with {gamma} rays. The effect of absorbed dose, monomer concentration, and reaction time on the degree of grafting was determined. The grafted samples were verified by FTIR-ATR spectroscopy. {beta}-Cyclodextrin was immobilized onto polypropylene modified with glycidyl methacrylate, and the ability of the cavities of {beta}-cyclodextrin to form inclusion complexes was demonstrated using the typically organic compound approach with m-toluic acid (3-MBA) as a probe.

  3. Novel water-soluble b-cyclodextrin-calix[4]arene couples as fluorescent sensor molecules for the detection of neutral analytes

    NARCIS (Netherlands)

    Bugler, H.J.; Engbersen, Johannes F.J.; Reinhoudt, David

    1998-01-01

    The synthesis and the host-guest chemistry of two novel fluorescent B-cyclodextrin-calix[4]arene couples 1 and 2 is described. The compounds were prepared by coupling a B-cyclodextrin linked with an aminoxylyl spacer with two different calix[4]arene building blocks each bearing a fluorophore. The

  4. Preparation and Evaluation of Taste Masked Famotidine Formulation Using Drug/β-cyclodextrin/Polymer Ternary Complexation Approach

    OpenAIRE

    Patel, Ashok R.; Vavia, Pradeep R.

    2008-01-01

    The main aim of the present study was to evaluate potential of ternary complexation (comprising of drug, cyclodextrin and polymer) as an approach for taste masking. For this purpose famotidine with property of bitter taste was selected as a model drug. Improvement in taste masking capability of cyclodextrin towards famotidine was evaluated by formulating a ternary complex including hydrophilic polymer hydroxyl propyl methyl cellulose (HPMC 5 cps) as the third component. Phase solubility analy...

  5. Study on the inclusion complex between β-cyclodextrin derivatives and flurbiprofen by spectrofluorometric

    Science.gov (United States)

    Miao, Jiabing; Guo, Zhaohua; Wang, Yongwang; Chen, Dong; Li, Yifan; Zhang, Feng

    2017-08-01

    The inclusion behavior between β-cyclodextrin derivatives (β-CDs) and flurbiprofen had been studied by fluorescence spectrophotometry. The effects of type and concentration of β-CDs; ionic strength; pH as well as temperature on inclusion behavior were investigated. And then the thermodynamic parameters ΔH/ΔS and ΔG of the inclusion complex of flurbiprofen and HP-β-CD were calculated, the driving force of the inclusion reaction had been also certified. The experimental results indicate, the fluorescence intensity (F) of flurbiprofen increases with the raising of β-CDs concentration, among the studied types of β-cyclodextrin derivatives, hydroxypropy l-β-cyclodextrin (HP-β-CD) has the most obvious enhancement, namely HP-β-CD has the strongest ability to complex with flurbiprofen. Plot of 1/ (F-F0) against 1/ [β-CD] yields a straight line, indicating 1:1 stoichiometric complex formed between β-CDs and flurbiprofen. Inclusion constant is enhanced with the increase in ionic strength of solution, whereas followes an opposite tendency with the rise of pH value. In the inclusive process, under normal temperature ΔG<0, it illustrates that this process is spontaneous, and the driving force is the change of enthalpy.

  6. Cyclodextrins improving the physicochemical and pharmacological properties of antidepressant drugs: a patent review.

    Science.gov (United States)

    Diniz, Tâmara Coimbra; Pinto, Tiago Coimbra Costa; Menezes, Paula Dos Passos; Silva, Juliane Cabral; Teles, Roxana Braga de Andrade; Ximenes, Rosana Christine Cavalcanti; Guimarães, Adriana Gibara; Serafini, Mairim Russo; Araújo, Adriano Antunes de Souza; Quintans Júnior, Lucindo José; Almeida, Jackson Roberto Guedes da Silva

    2018-01-01

    Depression is a serious mood disorder and is one of the most common mental illnesses. Despite the availability of several classes of antidepressants, a substantial percentage of patients are unresponsive to these drugs, which have a slow onset of action in addition to producing undesirable side effects. Some scientific evidence suggests that cyclodextrins (CDs) can improve the physicochemical and pharmacological profile of antidepressant drugs (ADDs). The purpose of this paper is to disclose current data technology prospects involving antidepressant drugs and cyclodextrins. Areas covered: We conducted a patent review to evaluate the antidepressive activity of the compounds complexed in CDs, and we analyzed whether these complexes improved their physicochemical properties and pharmacological action. The present review used 8 specialized patent databases for patent research, using the term 'cyclodextrin' combined with 'antidepressive agents' and its related terms. We found 608 patents. In the end, considering the inclusion criteria, 27 patents reporting the benefits of complexation of ADDs with CDs were included. Expert opinion: The use of CDs can be considered an important tool for the optimization of physicochemical and pharmacological properties of ADDs, such as stability, solubility and bioavailability.

  7. In vitro investigations of α-amylase mediated hydrolysis of cyclodextrins in the presence of ibuprofen, flurbiprofen, or benzo[a]pyrene

    DEFF Research Database (Denmark)

    Riisager, Ludmilla Lumholdt; Holm, R.; Jørgensen, E. B.

    2012-01-01

    -γ-cyclodextrins have different biopharmaceutical behaviours than the other evaluated cyclodextrins. The rate of degradation was affected by the addition of the inclusion complex forming additives flurbiprofen, ibuprofen and benzo[a]pyrene. This effect between the degradation dynamics and the included additives...

  8. New compositions of cadmium selenium nanoparticles and dye molecules with cyclodextrin inclusion complexes

    International Nuclear Information System (INIS)

    Asimov, M.M.; Anufrik, S.S.; Tarkovsky, V.V.; Sazonko, H.H.

    2013-01-01

    Spectroscopic properties of new heterogeneous multicolor compositions based on cadmium selenium (CdSe/ZnS) nano crystal and inclusion complexes of dye molecule with cyclodextrin are presented. Spectral fluorescence of proposed compositions investigated in thin films. Signals from multicolor fluorescence of proposing compositions may be combined to definite spectral codes that could be used for tracking or verification of different objects. Calibration bar of signal within spectral codes guarantee high reliability in practical application of proposed multicolor compositions. Express analysis the size of nanoparticles during their synthesis and purification by spectroscopic methods is suggested. Application of Cyclodextrin molecules as target delivery systems is considered. (authors)

  9. Effect of cyclodextrin-loaded cholesterol conjugates on plasma membrane viability of Piau swine breed frozen/thawed spermatozoa.

    Science.gov (United States)

    Pinho, R O; Lima, D M A; Shiomi, H H; Siqueira, J B; Silveira, C O; Faria, V R; Lopes, P S; Guimarães, S E F; Guimarães, J D

    2016-08-01

    The objective of this study was to investigate the effect of cyclodextrin-loaded cholesterol conjugates addition to freezing extenders on plasma membrane viability of frozen-thawed spermatozoa of the Piau swine breed. Twenty semen samples were used from five males. The freezing extender was based on lactose-egg yolk extender, added to 2% glycerol, 3% dimethylacetamide. The addition of cyclodextrin-loaded cholesterol conjugates was performed after centrifugation, when semen was diluted with the cooling extender. Four groups were subjected to the following treatment: without addition (group 1); 1.5 mg of cyclodextrin-loaded cholesterol/120 × 10(6) sperm (group 2); 1.5 mg of cyclodextrin-loaded cholestanol/120 × 10(6) sperm (group 3); 1.5 mg of cyclodextrin-loaded desmosterol/120 × 10(6) sperm (group 4). To check post-thawing sperm quality sperm motility and sperm morphology evaluation were used. Additionally, to check sperm viability the hypoosmotic swelling test, supravital staining, and fluorescent assay were used. The mean values recorded for total sperm motility of semen immediately after thawing were 54.5 ± 5.8, 55.5 ± 5.3, 53.7 ± 6.7, and 52.5 ± 6.6% respectively for groups one to four, without difference between themselves (p > 0.05). Regarding fluorescent assay the results were 28.3 ± 13.2, 26.9 ± 12.2, 22.2 ± 11.4, and 32.0 ± 15.3% respectively for groups one to four, also without difference between groups (p > 0,05). Similarly, complementary tests for evaluating the integrity and functionality of the plasma membrane showed no difference between treatments (p > 0.05). In conclusion, use of cyclodextrin-loaded cholesterol conjugates added to the plasma membrane of sperm did not demonstrate any additive effect on increasing and/or maintaining sperm motility. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Alpha- and Beta-Cyclodextrin Inclusion Complexes with 5-Fluorouracil: Characterization and Cytotoxic Activity Evaluation

    Directory of Open Access Journals (Sweden)

    Cristina Di Donato

    2016-12-01

    Full Text Available Cyclodextrins are natural macrocyclic oligosaccharides able to form inclusion complexes with a wide variety of guests, affecting their physicochemical and pharmaceutical properties. In order to obtain an improvement of the bioavailability and solubility of 5-fluorouracil, a pyrimidine analogue used as chemotherapeutic agent in the treatment of the colon, liver, and stomac cancers, the drug was complexed with alpha- and beta-cyclodextrin. The inclusion complexes were prepared in the solid state by kneading method and characterized by Fourier transform-infrared (FT-IR spectroscopy and X-ray powder diffractometry. In solution, the 1:1 stoichiometry for all the inclusion complexes was established by the Job plot method and the binding constants were determined at different pHs by UV-VIS titration. Furthermore, the cytotoxic activity of 5-fluorouracil and its complexation products were evaluated using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay on MCF-7 (breast cancer cell line, Hep G2 (hepatocyte carcinoma cell line, Caco-2 (colon adenocarcinoma cell line, and A-549 (alveolar basal epithelial carcinoma cell line. The results showed that both inclusion complexes increased the 5-fluorouracil capability of inhibiting cell growth. In particular, 5-fluorouracil complexed with beta-cyclodextrin had the highest cytotoxic activity on MCF-7; with alpha-cyclodextrin the highest cytotoxic activity was observed on A-549. The IC50 values were equal to 31 and 73 µM at 72 h, respectively. Our results underline the possibility of using these inclusion complexes in pharmaceutical formulations for improving 5-fluorouracil therapeutic efficacy.

  11. Cyclodextrin promotes atherosclerosis regression via macrophage reprogramming

    DEFF Research Database (Denmark)

    Zimmer, Sebastian; Grebe, Alena; Bakke, Siril S

    2016-01-01

    -containing lipoproteins in the subendothelial space causes a local overabundance of free cholesterol. Because cholesterol accumulation and deposition of cholesterol crystals (CCs) trigger a complex inflammatory response, we tested the efficacy of the cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (CD), a compound...... of CD as well as for augmented reverse cholesterol transport. Because CD treatment in humans is safe and CD beneficially affects key mechanisms of atherogenesis, it may therefore be used clinically to prevent or treat human atherosclerosis....

  12. Synthesis and study of anhydro-cyclodextrins: application to decontamination in biological medium

    International Nuclear Information System (INIS)

    Pailler, J.Y.

    2004-01-01

    Per anhydro α-cyclodextrin exhibits in vivo and in vitro cation complexing properties. Furthermore, they have a high affinity for heavy toxic cations, while a quite negligible affinity for physiological cations (Na + , Ca 2+ , K + ), that is to say a great selectivity. In order to apply these properties for biological decontamination, several alkyl derivatives were prepared by substitution at the 2 position and their cation complexing properties studied by 1 H-NMR spectroscopy. Superficial tension measurements, 1 H-NMR spectroscopy and gel formation showed that the properties of per anhydro cyclodextrin were tightly related with Log P, which also controlled their interactions with membranes. Membranes interactions are studied by surface plasmon resonance using BIAcore, 31 P-NMR and 2 H-NMR spectroscopies. (author) [fr

  13. Cyclodextrin-based artificial oxidases with high rate accelerations and selectivity

    DEFF Research Database (Denmark)

    Zhou, You; Lindbäck, Emil Anders; Pedersen, Christian Marcus

    2014-01-01

    Three cyclodextrin derivatives with one to four 2-O-formylmethyl groups attached to the secondary rim were prepared and investigated as catalysts for the oxidation of aminophenols in buffered dilute hydrogen peroxide. The derivatives were found to be Michaelis-Menten catalysts and to give rate ac...

  14. Molecular printboards: monolayers of beta-cyclodextrins on silicon oxide surfaces

    NARCIS (Netherlands)

    Onclin, S.; Mulder, A.; Huskens, Jurriaan; Ravoo, B.J.; Reinhoudt, David

    2004-01-01

    Monolayers of β-cyclodextrin host molecules have been prepared on SiO2 surfaces. An ordered and stable cyano-terminated monolayer was modified in three consecutive surface reactions. First, the cyanide groups were reduced to their corresponding free amines using Red Al as a reducing agent. Second,

  15. Thermodynamic investigation of the interaction between cyclodextrins and preservatives - Application and verification in a mathematical model to determine the needed preservative surplus in aqueous cyclodextrin formulations

    DEFF Research Database (Denmark)

    Holm, René; Olesen, Niels Erik; Alexandersen, Signe Dalgaard

    2016-01-01

    Preservatives are inactivated when added to conserve aqueous cyclodextrin (CD) formulations due to complex formation between CDs and the preservative. To maintain the desired conservation effect the preservative needs to be added in apparent surplus to account for this inactivation. The purpose o...

  16. Preparation and characterization of carbons from β-cyclodextrin dehydration and from olive pomace activation and their application for boron

    Directory of Open Access Journals (Sweden)

    Mouna Jaouadi

    2017-11-01

    Full Text Available An activated carbon was prepared by phosphoric activation of olive pomace and further oxidation by nitric acid. Another carbon was obtained from β-cyclodextrin dehydration in concentrated sulfuric acid. A composite of the oxidized activated carbon and the carbon from β-cyclodextrin was prepared. The four materials were characterized by N2 adsorption–desorption measurements, X-ray diffraction, infrared and Raman spectroscopies, elemental analysis, “Boehm” titration and measurements of pH of the point zero charge. The obtained adsorbents were tested for boron adsorption in aqueous solution. Despite their lowest specific surface areas, the composite carbon and the amorphous carbon from cyclodextrin dehydration showed the highest boron adsorption uptake (1.41 and 1.68 mg·g−1 compared to the raw (1.05 mg·g−1 and oxidized (0.95 mg·g−1 activated carbons. The surface chemistry particularly rich in phenolic groups was responsible for the high boron adsorption uptake of the carbon composite and the amorphous carbon, both prepared through cyclodextrin dehydration.

  17. Cyclodextrin inclusion complexes with thiocholesterol and their self-assembly on gold: A combined electrochemical and lateral force microscopy analysis

    International Nuclear Information System (INIS)

    Pandey, Rakesh K.; Lakshminarayanan, V.

    2014-01-01

    The present study is an attempt to understand the properties of an interesting self-assembled monolayer system composed of inclusion complexes of thiocholesterol and cyclodextrins. Cyclodextrins were used as host compound while thiocholesterol was used as the entrant molecule into the cavity of cyclodextrins. The improved electron transfer barrier property towards a redox couple indicates a sturdy inclusion complex monolayer. A very large R ct value, 64.6 kΩ·cm 2 for a redox system was obtained in the case of methyl-β-cyclodextrin and thiocholesterol inclusion complex self-assembled monolayer. A rather low value of capacitance 1.2 μF cm −2 measured in supporting electrolyte further signifies the fact that inclusion complex monolayer is quite impermeable for ionic species. In addition lateral force microscopy combined with force–distance analysis revealed the presence of an interesting mixed hydrophilic/hydrophobic surface. - Highlights: • Self-assembled monolayer of inclusion complexes on gold surface • Lateral force microscopy study of the regions of varying hydrophilicities • Could find applications in patterning surfaces to be hydrophilic/hydrophobic • Improved electron transfer barrier properties

  18. DSC, X-ray and FTIR studies of a gemfibrozil/dimethyl-β-cyclodextrin inclusion complex produced by co-grinding.

    Science.gov (United States)

    Aigner, Z; Berkesi, O; Farkas, G; Szabó-Révész, P

    2012-01-05

    The steps of formation of an inclusion complex produced by the co-grinding of gemfibrozil and dimethyl-β-cyclodextrin were investigated by differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD) and Fourier transform infrared (FTIR) spectroscopy with curve-fitting analysis. The endothermic peak at 59.25°C reflecting the melting of gemfibrozil progressively disappeared from the DSC curves of the products on increase of the duration of co-grinding. The crystallinity of the samples too gradually decreased, and after 35min of co-grinding the product was totally amorphous. Up to this co-grinding time, XRPD and FTIR investigations indicated a linear correlation between the cyclodextrin complexation and the co-grinding time. After co-grinding for 30min, the ratio of complex formation did not increase. These studies demonstrated that co-grinding is a suitable method for the complexation of gemfibrozil with dimethyl-β-cyclodextrin. XRPD analysis revealed the amorphous state of the gemfibrozil-dimethyl-β-cyclodextrin product. FTIR spectroscopy with curve-fitting analysis may be useful as a semiquantitative analytical method for discriminating the molecular and amorphous states of gemfibrozil. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Ion-exclusion chromatography with conductimetric detection of aliphatic carboxylic acids on a weakly acidic cation-exchange resin by elution with benzoic acid-beta-cyclodextrin.

    Science.gov (United States)

    Tanaka, Kazuhiko; Mori, Masanobu; Xu, Qun; Helaleh, Murad I H; Ikedo, Mikaru; Taoda, Hiroshi; Hu, Wenzhi; Hasebe, Kiyoshi; Fritz, James S; Haddad, Paul R

    2003-05-16

    In this study, an aqueous solution consisting of benzoic acid with low background conductivity and beta-cyclodextrin (beta-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pKa values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of beta-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of beta-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of beta-cyclodextrin in 1 mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a 1 mM benzoic acid-10 mM cyclodextrin solution without chemical suppression.

  20. Development of Buccal Patches for Delivery of Darifenacin from Beta-Cyclodextrin Complexes

    Directory of Open Access Journals (Sweden)

    Swati C. Jagdale

    2014-01-01

    Full Text Available Drug-cyclodextrin complexes improve aqueous solubility and dissolution rate of poorly water-soluble drugs. Solubilisation followed by buccal delivery of poorly water-soluble drugs can be advantageous for increasing drug absorption. Darifenacin is an antispasmodic used against urinary incontinence and specifically blocks M3 muscarinic acetylcholine receptors in smooth muscle. M3 receptors are mainly located in exocrine glands, smooth muscle and vascular endothelium. The oral absorption of darifenacin is poor owing to its low solubility. It also has poor bioavailability (15-19% due to a high rate of first-pass metabolism. Complexation with beta-cyclodextrin was carried out to enhance solubility. The best results were obtained by co-grinding in a 1:1 molar ratio of drug: β-cyclodextrin. The solid inclusion complexes were characterized by DSC, X-ray diffractometry and FTIR. Inclusion complexes showed higher dissolution rates than the pure drug. Controlledrelease mucoadhesive patches were prepared with two hydroxypropyl methylcellulose (HPMC polymers, K100M CR and K15. The patches were assessed for surface pH, folding endurance, swelling, mucoadhesive properties, in-vitro residence time, vapor transmission test and in-vitro (cellophane, egg membrane and exvivo (goat buccal mucosa release. Formulations Ha2 (2% HPMC K100M CR and Pa4 (4% HPMC K15 showed good mucoadhesive strength, in-vitro and exvivo residence times, with controlled release for 10 hours.

  1. Trapping of polycyclic aromatic hydrocarbons by amphiphilic cyclodextrin functionalized polypropylene nonwovens

    DEFF Research Database (Denmark)

    Lumholdt, Ludmilla; Nielsen, Ronnie Bo Højstrup; Larsen, Kim Lambertsen

    of the textile fibers. In this study we present the ability of amphiphilic CD coated polypropylene nonwovens to trap 8 different polycyclic aromatic hydrocarbons/endocrine disruptors from aqueous solutions thus demonstrating the potential of using the amphiphilic cyclodextrins for water purification....

  2. Interaction of serum albumins with cyclodextrins: How safe is the use ...

    Indian Academy of Sciences (India)

    Interaction of cyclodextrins with human and bovine serum albumin: A combined spectroscopic and computational investigation. Saptarshi Ghosh, Bijan Kumar Paul, Nitin Chattopadhyay*. Department of Chemistry, Jadavpur University, Kolkata - 700 032, India. *Corresponding author: Fax: 91-33-2414 6584. E-mail: ...

  3. Structure–efficiency relationships of cyclodextrin scavengers in the hydrolytic degradation of organophosphorus compounds

    Directory of Open Access Journals (Sweden)

    Sophie Letort

    2017-03-01

    Full Text Available New derivatives of cyclodextrins were prepared in order to determine the relative importance of the structural key elements involved in the degradation of organophosphorus nerve agents. To avoid a competitive inclusion between the organophosphorus substrate and the iodosobenzoate group, responsible for its degradation, the latter group had to be covalently bound to the cyclodextrin scaffold. Although the presence of the α nucleophile iodosobenzoate was a determinant in the hydrolysis process, an imidazole group was added to get a synergistic effect towards the degradation of the agents. The degradation efficiency was found to be dependent on the relative position of the heterocycle towards the reactive group as well as on the nature of the organophosphorus derivative.

  4. Application of cyclodextrins in antibody microparticles: potentials for antibody protection in spray drying.

    Science.gov (United States)

    Ramezani, Vahid; Vatanara, Alireza; Seyedabadi, Mohammad; Nabi Meibodi, Mohsen; Fanaei, Hamed

    2017-07-01

    Dry powder formulations are extensively used to improve the stability of antibodies. Spray drying is one of important methods for protein drying. This study investigated the effects of trehalose, hydroxypropyl beta cyclodextrin (HPBCD) and beta cyclodextrin (BCD) on the stability and particle properties of spray-dried IgG. D-optimal design was employed for both experimental design and analysis and optimization of the variables. The size and aerodynamic behavior of particles were determined using laser light scattering and glass twin impinger, respectively. In addition, stability, ratio of beta sheets and morphology of antibody were analyzed using size exclusion chromatography, IR spectroscopy and electron microscopy, respectively. Particle properties and antibody stability were significantly improved in the presence of HPBCD. In addition, particle aerodynamic behavior, in terms of fine-particle fraction (FPF), enhanced up to 52.23%. Furthermore, antibody was better preserved not only during spray drying, but also during long-term storage. In contrast, application of BCD resulted in the formation of larger particles. Although trehalose caused inappropriate aerodynamic property, it efficiently decreased antibody aggregation. HPBCD is an efficient excipient for the development of inhalable protein formulations. In this regard, optimal particle property and antibody stability was obtained with proper combination of cyclodextrins and simple sugars, such as trehalose.

  5. Graphene-cyclodextrin-cytochrome c layered assembly with improved electron transfer rate and high supramolecular recognition capability.

    Science.gov (United States)

    Gong, Cheng-Bin; Guo, Cong-Cong; Jiang, Dan; Tang, Qian; Liu, Chang-Hua; Ma, Xue-Bing

    2014-06-01

    This study aimed to develop a new graphene-based layered assembly, named graphene-cyclodextrin-cytochrome c with improved electron transfer rate. This assembly has combined high conductivity of graphene nanosheets (GNs), selectively binding properties and electronegativity of cyclodextrins (CDs), as well as electropositivity of cytochrome c (Cyt c). This assembly can also mimic the confined environments of the intermembrane space of mitochondria. A β-cyclodextrin (β-CD) functionalized GN (GN-CD) assembly was initially prepared by a simple wet-chemical strategy, i.e., in situ thermal reduction of graphene oxide with hydrazine hydrate in the presence of β-CD. Cyt c was then intercalated to the GN-CD assembly to form a layered self-assembled structure, GN-CD-Cyt c, through electrostatic interaction. Compared with GNs and GN-CD, GN-CD-Cyt c assembly displayed improved electron transfer rate and high supramolecular recognition capability toward six probe molecules. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Cyclodextrin-Triazole Derivative Functionalized on Ag-SiO{sub 2} Core-Shell Nanoparticles via Click Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gun Bae; Singu, Bal Sydulu; Hong, Sang Eun; Yoon, Kuk Ro [Hannam Univ., Daejeon (Korea, Republic of)

    2016-09-15

    Click chemistry has provided a versatile strategy for functionalization in solution chemistry under mild reaction conditions with a high degree of functional group compatibility. Initially, silver (Ag) nanoparticles were prepared by the chemical reduction method, followed by the synthesis of silver–silica (Ag–SiO{sub 2}) core–shell nanoparticles by the Stöber method. The Ag–SiO2 core shell nanoparticles were functionalized with the alkyne derivative. The cycloaddition reaction between the azide-functionalized cyclodextrin and the alkyne-functionalized Ag–SiO{sub 2} core–shell nanoparticles was carried out via the copper-catalyzed click reaction, leading to the formation of the cyclodextrin-triazole derivative on the Ag–SiO{sub 2} core–shell nanoparticles. The presence of the resulting cyclodextrin-triazole derivative on the silver–silica core–shell nanoparticles was confirmed by Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV–vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA).

  7. A novel in situ strategy for the preparation of a β-cyclodextrin/polydopamine-coated capillary column for capillary electrochromatography enantioseparations.

    Science.gov (United States)

    Guo, Heying; Niu, Xiaoying; Pan, Congjie; Yi, Tao; Chen, Hongli; Chen, Xingguo

    2017-06-01

    Inspired by the chiral recognition ability of β-cyclodextrin and the natural adhesive properties of polydopamine under alkaline conditions, in this study, a rapid and in situ modification strategy was developed to fabricate β-cyclodextrin/polydopamine composite material coated-capillary columns for open tubular capillary electrochromatography. The results of scanning electron microscopy, FTIR spectroscopy, streaming potential, and electro-osmotic flow studies indicated that β-cyclodextrin/polydopamine was successfully fixed on the inner wall of the capillary column. This coating can be achieved within 1 h affording a greatly reduced capillary preparation time. The performance of the β-cyclodextrin/polydopamine-coated capillary was validated by the analysis of seven pairs of chiral analytes, namely epinephrine, norepinephrine, isoprenaline, terbutaline, verapamil, tryptophane, carvedilol. Good enantioseparation efficiencies were achieved for all. For three consecutive runs, the relative standard deviations for the migration times of the analytes for intraday, interday, and column-to-column repeatability were in the range of 0.41-1.74, 1.03-4.18, and 1.66-8.24%, respectively. Moreover, the separation efficiency of the β-cyclodextrin/polydopamine-coated capillary column did not decrease obviously over 90 runs. The strategy should also be feasible to introduce and immobilize other chiral selectors on the inner walls surface of capillary columns. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Microcalorimetric and spectrographic studies on host-guest interactions of {alpha}-, {beta}-, {gamma}- and M{beta}-cyclodextrin with resveratrol

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui; Xu, Xiangyu; Liu, Min [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Sun, Dezhi, E-mail: sundezhisdz@163.com [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Li, Linwei, E-mail: lilinwei@lcu.edu.cn [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China)

    2010-10-20

    Thermal effects of inclusion processes of {alpha}-, {beta}-, {gamma}- and M{beta}-cyclodextrin with resveratrol (RES) in aqueous solutions were determined by isothermal titration calorimetry (ITC) with nanowatt sensitivity at the temperature of 298.15 K. Standard enthalpy changes, stoichiometry and equilibrium constants of the inclusion complexes were derived from the direct calorimetric data utilizing nonlinear simulation. The thermodynamic parameters were discussed in the light of weak interactions between the host and the guest molecules combining with UV spectral message. The results indicate that all of the complexes formed in the aqueous solutions are in 1:1 stoichiometry. The binding processes of {alpha}-, {beta}- and M{beta}-cyclodextrin with the guest are mainly driven by enthalpy, while that of {gamma}-cyclodextrin with the drug is driven by both enthalpy and entropy.

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

    Directory of Open Access Journals (Sweden)

    Francesco Trotta

    2014-11-01

    Full Text Available 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.

  10. Enhancement of dibenzothiophene biodesulfurization using {beta}-cyclodextrins in oil-to-water media

    Energy Technology Data Exchange (ETDEWEB)

    Ainhoa Caro; Pedro Leton; Eloy Garcia-Calvo; Leonardo Setti [Universidad de Alcala, Madrid (Spain). Departamento de Quimica Analitica e Ingeniera Quimica

    2007-11-15

    It has been reported that biodesulfurization (BDS) of dibenzothiophene (DBT) in oil-to-water emulsions is carried out by growing cells of the aerobic Rhodococcus erythropolis IGTS8 strain and developing the so-called 4S desulfurization pathway. On adding {beta}-cyclodextrins, it is possible to improve the BDS yields, increase the diffusion of DBT into the aqueous phase or avoid the HBP accumulation. Moreover, by using greater biocatalyst initial concentrations and adding 15 ppm of {beta}-cyclodextrin, a very high BDS yield has been observed, but the presence of mass transfer limitations and the inhibition effects were not satisfactorily avoided. The Haldane kinetic model agreed well with the experimental results obtained, and the values of the kinetic parameters were determined. Short communication. 20 refs., 2 figs., 2 tabs.

  11. Optimized methods for preparation of 6I-(ω-sulfanyl-alkylene-sulfanyl-β-cyclodextrin derivatives

    Directory of Open Access Journals (Sweden)

    Eva Bednářová

    2016-02-01

    Full Text Available A general high-yielding method for the preparation of monosubstituted β-cyclodextrin derivatives which have attached a thiol group in position 6 is described. The thiol group is attached through linkers of different lengths and repeating units (ethylene glycol or methylene. The target compounds were characterized by IR, MS and NMR spectra. A simple method for their complete conversion to the corresponding disulfides as well as a method for the reduction of the disulfides back to the thiols is presented. Both, thiols and disulfides are derivatives usable for well-defined covalent attachment of cyclodextrin to gold or polydopamine-coated solid surfaces.

  12. Cyclodextrin based nanosponges for pharmaceutical use: a review.

    Science.gov (United States)

    Tejashri, Gursalkar; Amrita, Bajaj; Darshana, Jain

    2013-09-01

    Nanosponges are a novel class of hyper-crosslinked polymer based colloidal structures consisting of solid nanoparticles with colloidal sizes and nanosized cavities. These nano-sized colloidal carriers have been recently developed and proposed for drug delivery, since their use can solubilize poorly water-soluble drugs and provide prolonged release as well as improve a drug's bioavailability by modifying the pharmacokinetic parameters of actives. Development of nanosponges as drug delivery systems, with special reference to cyclodextrin based nanosponges, is presented in this article. In the current review, attempts have been made to illustrate the features of cyclodextrin based nanosponges and their applications in pharmaceutical formulations. Special emphasis has been placed on discussing the methods of preparation, characterization techniques and applications of these novel drug delivery carriers for therapeutic purposes. Nanosponges can be referred to as solid porous particles having a capacity to load drugs and other actives into their nanocavity; they can be formulated as oral, parenteral, topical or inhalation dosage forms. Nanosponges offer high drug loading compared to other nanocarriers and are thus suitable for solving issues related to stability, solubility and delayed release of actives. Controlled release of the loaded actives and solubility enhancement of poorly water-soluble drugs are major advantages of nanosponge drug delivery systems.

  13. Biopharmaceutical characterization of praziquantel cocrystals and cyclodextrin complexes prepared by grinding.

    Science.gov (United States)

    Cugovčan, Martina; Jablan, Jasna; Lovrić, Jasmina; Cinčić, Dominik; Galić, Nives; Jug, Mario

    2017-04-15

    Mechanochemical activation using several different co-grinding additives was applied as a green chemistry approach to improve physiochemical and biopharmaceutical properties of praziquantel (PZQ). Liquid assisted grinding with an equimolar amount of citric acid (CA), malic acid (MA), salicylic acid (SA) and tartaric acid (TA) gained in cocrystal formation, which all showed pH-dependent solubility and dissolution rate. However, the most soluble cocrystal of PZQ with MA was chemically unstable, as seen during the stability testing. Equimolar cyclodextrin complexes prepared by neat grinding with amorphous hydroxypropyl-β-cyclodextrin (HPβCD) and randomly methylated β-cyclodextrin (MEβCD) showed the highest improvement in drug solubility and the dissolution rate, but only PZQ/HPβCD product presented an acceptable chemical and photostability profile. A combined approach, by co-grinding the drug with both MA and HPβCD in equimolar ratio, also gave highly soluble amorphous product which again was chemical instable and therefore not suitable for the pharmaceutical use. Studies on Caco-2 monolayer confirmed the biocompatibility of PZQ/HPβCD complex and showed that complexation did not adversely affect the intrinsically high PZQ permeability (P app (PZQ)=(3.72±0.33)×10 -5 cms -1 and P app (PZQ/HPβCD)=(3.65±0.21)×10 -5 cms -1 ; p>0.05). All this confirmed that the co-grinding with the proper additive is as a promising strategy to improve biopharmaceutical properties of the drug. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Enhancement of carvedilol solubility by solid dispersion technique using cyclodextrins, water soluble polymers and hydroxyl acid.

    Science.gov (United States)

    Yuvaraja, K; Khanam, Jasmina

    2014-08-05

    Aim of the present work is to enhance aqueous solubility of carvedilol (CV) by solid dispersion technique using wide variety of carriers such as: β-cyclodextrin (βCD), hydroxypropyl-β-cyclodextrin (HPβCD), tartaric acid (TA), polyvinyl pyrrolidone K-30 (PVP K-30) and poloxamer-407 (PLX-407). Various products of 'CV-solid dispersion' had been studied extensively in various pH conditions to check enhancement of solubility and dissolution characteristics of carvedilol. Any physical change upon interaction between CV and carriers was confirmed by instrumental analysis: XRD, DSC, FTIR and SEM. Negative change of Gibb's free energy and complexation constants (Kc, 75-240M(-1), for cyclodextrins and 1111-20,365M(-1), for PVP K-30 and PLX-407) were the evidence of stable nature of the binding between CV and carriers. 'Solubility enhancement factor' of ionized-CV was found high enough (340 times) with HPβCD in presence of TA. TA increases the binding efficiency of cyclodextrin and changing the pH of microenvironment in dissolution medium. In addition, ionization process was used to increase the apparent intrinsic solubility of drug. In vitro, dissolution time of CV was remarkably reduced in the solid dispersion system compared to that of pure drug. This may be attributed to increased wettability, dispersing ability and transformation of crystalline state of drug to amorphous one. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. The solubility-permeability interplay in using cyclodextrins as pharmaceutical solubilizers: mechanistic modeling and application to progesterone.

    Science.gov (United States)

    Dahan, Arik; Miller, Jonathan M; Hoffman, Amnon; Amidon, Gregory E; Amidon, Gordon L

    2010-06-01

    A quasi-equilibrium mass transport analysis has been developed to quantitatively explain the solubility-permeability interplay that exists when using cyclodextrins as pharmaceutical solubilizers. The model considers the effects of cyclodextrins on the membrane permeability (P(m)) as well as the unstirred water layer (UWL) permeability (P(aq)), to predict the overall effective permeability (P(eff)) dependence on cyclodextrin concentration (C(CD)). The analysis reveals that: (1) UWL permeability markedly increases with increasing C(CD) since the effective UWL thickness quickly decreases with increasing C(CD); (2) membrane permeability decreases with increasing C(CD), as a result of the decrease in the free fraction of drug; and (3) since P(aq) increases and P(m) decreases with increasing C(CD), the UWL is effectively eliminated and the overall P(eff) tends toward membrane control, that is, P(eff) approximately P(m) above a critical C(CD). Application of this transport model enabled excellent quantitative prediction of progesterone P(eff) as a function of HP beta CD concentrations in PAMPA assay, Caco-2 transepithelial studies, and in situ rat jejunal-perfusion model. This work demonstrates that when using cyclodextrins as pharmaceutical solubilizers, a trade-off exists between solubility increase and permeability decrease that must not be overlooked; the transport model presented here can aid in striking the appropriate solubility-permeability balance in order to achieve optimal overall absorption. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  16. Synthesis of Some Trifluoromethylated Cyclodextrin Derivatives and Analysis of Their Properties as Artificial Glycosidases and Oxidases

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Fenger, Thomas Hauch; Marinescu, Lavinia Georgeta

    2007-01-01

    Cyclodextrin derivatives containing trifluoromethyl groups at C6 of the A and D rings were synthesized for the purpose of creating artificial enzymes. The compounds were synthesized by perbenzylation of beta-cyclodextrin followed by selective A,D-debenzylation according to Sinaÿ. Subsequent...... deprotected. The trifluoromethylated alcohols were found to be weak artificial enzymes catalysing hydrolysis of nitrophenyl glycosides at neutral pH with a kcat/kuncat of up to 56. It is proposed that this catalysis is analogues to the catalysis performed by related cyanohydrins. The trifluoro ketones were...

  17. Enhancement of Hybrid SPEEK Based Polymer–Cyclodextrin-Silica Inorganic Membrane for Direct Methanol Fuel Cell Application

    Directory of Open Access Journals (Sweden)

    Tutuk Djoko Kusworo

    2017-06-01

      Keywords: Direct Methanol Fuel Cell, Poly(ether ether ketone, cyclodextrin-silica, sulfonation, ionic conductivity. Article History: Received January 18th 2017; Received in revised form April 21st 2017; Accepted June 22nd 2017; Available online How to Cite This Article: Kusworo, T.D., Hakim, M.F. and Hadiyanto, H. (2017 Enhancement of Hybrid SPEEK Based Polymer–Cyclodextrin-Silica Inorganic Membrane for Direct Methanol Fuel Cell Application. International Journal of Renewable Energy Development, 6(2, 165-170. https://doi.org/10.14710/ijred.6.2.165-170

  18. Sorption of ochratoxin A from aqueous solutions using β-cyclodextrin-polyurethane polymer.

    Science.gov (United States)

    Appell, Michael; Jackson, Michael A

    2012-02-01

    The ability of a cyclodextrin-polyurethane polymer to remove ochratoxin A from aqueous solutions was examined by batch rebinding assays. The results from the aqueous binding studies were fit to two parameter models to gain insight into the interaction of ochratoxin A with the nanosponge material. The ochratoxin A sorption data fit well to the heterogeneous Freundlich isotherm model. The polymer was less effective at binding ochratoxin A in high pH buffer (9.5) under conditions where ochratoxin A exists predominantly in the dianionic state. Batch rebinding assays in red wine indicate the polymer is able to remove significant levels of ochratoxin A from spiked solutions between 1-10 μg·L(-1). These results suggest cyclodextrin nanosponge materials are suitable to reduce levels of ochratoxin A from spiked aqueous solutions and red wine samples.

  19. A Click Chemistry Approach towards Flavin-Cyclodextrin Conjugates-Bioinspired Sulfoxidation Catalysts

    Czech Academy of Sciences Publication Activity Database

    Tomanová, P.; Šturala, J.; Buděšínský, Miloš; Cibulka, R.

    2015-01-01

    Roč. 20, č. 11 (2015), s. 19837-19848 ISSN 1420-3049 Institutional support: RVO:61388963 Keywords : click chemistry * cyclodextrin * flavin * monooxygenase * oxidation * sulfoxides * green chemistry Subject RIV: CC - Organic Chemistry Impact factor: 2.465, year: 2015 http://www.mdpi.com/1420-3049/20/11/19667/htm

  20. Preparation of hydroxyapatite nanoparticles facilitated by the presence of {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Perez, Carlos A., E-mail: camartin@uacj.mx [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Garcia-Montelongo, Jorge; Garcia Casillas, Perla E.; Farias-Mancilla, Jose R. [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Monreal Romero, Humberto [School of Odontology, Autonomous University of Chihuahua, UACH, Ave. Universidad s/n Campus Universitario I, C.P. 31170, Chihuahua (Mexico)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer It was found that {beta}-cyclodextrin can control the particle size in the production of nanohydroxyapatite. Black-Right-Pointing-Pointer Particle size in the range of 30-50 nm was obtained. Black-Right-Pointing-Pointer A new simple methodology for the preparation of hydroxyapatite nanoparticles with a well controlled size and narrow particles size distribution was developed. - Abstract: Hydroxyapatite nanoparticles with uniform morphology have been successfully synthesized by a chemical coprecipitation method and facilitated by the presence of the {beta}-cyclodextrin. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM); and Fourier Transformed Infrared Spectroscopy (FT-IR) were used in order to characterize the hydroxyapatite samples. The experimental results indicate that the obtained HA is in the range of 20-50 nm. Also it was found that the content of {beta}-CD has an impact on the purity of the HA as well in the particle size of the hydroxyapatite nanoparticles.

  1. Preparation of hydroxyapatite nanoparticles facilitated by the presence of β-cyclodextrin

    International Nuclear Information System (INIS)

    Martínez-Pérez, Carlos A.; García-Montelongo, Jorge; Garcia Casillas, Perla E.; Farias-Mancilla, José R.; Monreal Romero, Humberto

    2012-01-01

    Highlights: ► It was found that β-cyclodextrin can control the particle size in the production of nanohydroxyapatite. ► Particle size in the range of 30–50 nm was obtained. ► A new simple methodology for the preparation of hydroxyapatite nanoparticles with a well controlled size and narrow particles size distribution was developed. - Abstract: Hydroxyapatite nanoparticles with uniform morphology have been successfully synthesized by a chemical coprecipitation method and facilitated by the presence of the β-cyclodextrin. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM); and Fourier Transformed Infrared Spectroscopy (FT-IR) were used in order to characterize the hydroxyapatite samples. The experimental results indicate that the obtained HA is in the range of 20–50 nm. Also it was found that the content of β-CD has an impact on the purity of the HA as well in the particle size of the hydroxyapatite nanoparticles.

  2. Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

    Directory of Open Access Journals (Sweden)

    Laszlo Jicsinszky

    2016-11-01

    Full Text Available A number of per-6-substituted cyclodextrin derivative syntheses have been effectively carried out in a planetary ball mill under solvent-free conditions. The preparation of Bridion® and important per-6-amino/thiocyclodextrin intermediates without polar aprotic solvents, a source of byproducts and persistent impurities, could be performed. Isolation and purification processes could also be simplified. Considerably lower alkylthiol/halide ratio were necessary to reach the complete reaction in comparison with thiourea or azide reactions. While the presented mechanochemical syntheses were carried out on the millimolar scale, they are easily scalable.

  3. Pharmaceutical Composition of Valsartan: β-Cyclodextrin: Physico–Chemical Characterization and Anti-Hypertensive Evaluation

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Matos Jensen

    2010-06-01

    Full Text Available Valsartan, a water-insoluble drug, is mainly used in the treatment of hypertension albeit with reduced oral bioavailability. The aim of work was to develop a valsartan:β-cyclodextrin (VAL:β-CD pharmaceutical composition in order to improve its water solubility and bioavailability. The VAL:β-CD complexes were prepared by the kneading, solid dispersion and freeze-drying methods, of which the freeze-drying method (FDY was found to be the best to prepare an inclusion complex. A physical mixtyure PM was also prepared. Complexes were characterized by thermal analysis, Fourier transformed- infrared (FTIR spectroscopy, Powder X-ray diffractometry, intrinsic dissolution and NMR (2D-ROESY. Phase-solubility analysis showed AL-type diagrams with β-cyclodextrin (β-CD. Microcalorimetric titrations suggested the formation of 1:1 inclusion complex between VAL and β-CD. The apparent stability constants K1:1 calculated from phase-solubility plots were 165.4 M-1 (298 K, 145.0 M-1 (303 K and 111.3 M-1 (310 K. In vivo experiments in rats showed that reduction in arterial pressure for the FDY complex is better than with valsartan used alone. The better activity of FDY can be attributed to the higher solubility of valsartan after inclusion in the cyclodextrin cavity, as suggest by the intrinsic dissolution studies.

  4. Melarsoprol cyclodextrin inclusion complexes as promising oral candidates for the treatment of human African trypanosomiasis.

    Directory of Open Access Journals (Sweden)

    Jean Rodgers

    2011-09-01

    Full Text Available Human African trypanosomiasis (HAT, or sleeping sickness, results from infection with the protozoan parasites Trypanosoma brucei (T. b. gambiense or T. b. rhodesiense and is invariably fatal if untreated. There are 60 million people at risk from the disease throughout sub-Saharan Africa. The infection progresses from the haemolymphatic stage where parasites invade the blood, lymphatics and peripheral organs, to the late encephalitic stage where they enter the central nervous system (CNS to cause serious neurological disease. The trivalent arsenical drug melarsoprol (Arsobal is the only currently available treatment for CNS-stage T. b. rhodesiense infection. However, it must be administered intravenously due to the presence of propylene glycol solvent and is associated with numerous adverse reactions. A severe post-treatment reactive encephalopathy occurs in about 10% of treated patients, half of whom die. Thus melarsoprol kills 5% of all patients receiving it. Cyclodextrins have been used to improve the solubility and reduce the toxicity of a wide variety of drugs. We therefore investigated two melarsoprol cyclodextrin inclusion complexes; melarsoprol hydroxypropyl-β-cyclodextrin and melarsoprol randomly-methylated-β-cyclodextrin. We found that these compounds retain trypanocidal properties in vitro and cure CNS-stage murine infections when delivered orally, once per day for 7-days, at a dosage of 0.05 mmol/kg. No overt signs of toxicity were detected. Parasite load within the brain was rapidly reduced following treatment onset and magnetic resonance imaging showed restoration of normal blood-brain barrier integrity on completion of chemotherapy. These findings strongly suggest that complexed melarsoprol could be employed as an oral treatment for CNS-stage HAT, delivering considerable improvements over current parenteral chemotherapy.

  5. Integral use of amaranth starch to obtain cyclodextrin glycosyltransferase, by Bacillus megaterium, to produce β-cyclodextrin.

    Directory of Open Access Journals (Sweden)

    María Belem Arce-Vázquez

    2016-09-01

    Full Text Available Cyclodextrin glycosyltransferase (CGTase is an enzyme that produces cyclodextrins (CDs from starch and related carbohydrates, producing a mixture of α-, β-, and γ-CDs in different amounts. CGTase production, mainly by Bacillus sp., depends on fermentation conditions such as pH, temperature, concentration of nutrients, carbon and nitrogen sources, among others. Bacillus megaterium CGTase produces those three types of CDs, however, β-CD should prevail. Although waxy corn starch (CS is used industrially to obtain CGTase and CDs because of its high amylopectin content, alternative sources such as amaranth starch (AS could be used to accomplish those purposes. AS has high susceptibility to the amylolytic activity of CGTase because of its 80% amylopectin content. Therefore, the aim of this work was evaluate the AS as carbon source for CGTase production by B. megaterium in a submerged fermentation. Afterwards, the CGTase was purified partially and its activity to synthesize α-, β- and γ-CDs was evaluated using 1% AS as substrate. B. megaterium produced a 66 kDa CGTase (Topt=50°C; pHopt=8.0, from the early exponential growth phase which lasted 36 h. The maximum CGTase specific activity (106.62±8.33 U/mg protein was obtained after 36 h of culture. CGTase obtained with a Km=0.152 mM and a Vmax=13.4 µM/min yielded 40.47% total CDs using AS which was roughly twice as much as that of corn starch (CS; 24.48%. High costs to produce CDs in the pharmaceutical and food industries might be reduced by using AS because of its higher α-, β- and γ-CDs production (12.81%, 17.94% and 9.92%, respectively in a shorter time than that needed for CS.

  6. β-Cyclodextrin coated CdSe/ZnS quantum dots for vanillin sensoring in food samples.

    Science.gov (United States)

    Durán, Gema M; Contento, Ana M; Ríos, Ángel

    2015-01-01

    An optical sensor for vanillin in food samples using CdSe/ZnS quantum dots (QDs) modified with β-cyclodextrin (β-CD) was developed. This vanillin-sensor is based on the selective host-guest interaction between vanillin and β-cyclodextrin. The procedure for the synthesis of β-cyclodextrin-CdSe/ZnS (β-CD-CdSe/ZnS-QDs) complex was optimized, and its fluorescent characteristics are reported. It was found that the interaction between vanillin and β-CD-CdSe/ZnS-QDs complex produced the quenching of the original fluorescence of β-CD-CdSe/ZnS-QDs according to the Stern-Volmer equation. The mechanism of the interaction is discussed. The analytical potential of this sensoring system was demonstrated by the determination of vanillin in synthetic and food samples. The method was selective for vanillin, with a limit of detection of 0.99 µg mL(-1), and a reproducibility of 4.1% in terms of relative standard deviation (1.2% under repeatability conditions). Recovery values were in the 90-105% range for food samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Simultaneous separation and determination of four uncaria alkaloids by capillary electrophoresis using dual cyclodextrin system.

    Science.gov (United States)

    Li, Lou; Xu, Liying; Chen, Meng; Zhang, Guangbin; Zhang, Hongfen; Chen, Anjia

    2017-07-15

    The purpose of this study was to develop a simple, quick and precise capillary zone electrophoresis method (CZE) for the separation and determination of uncaria alkaloids using dual cyclodextrins as additives for the separation. The four analytes were baseline separated within 15min at the applied voltage of 15kV with a running buffer (pH 5.7) consisting of 40.0mM phosphate buffer, 161.7mM 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and 2.21mM mono-(6-ethylenediamine-6-deoxy)-β-cyclodextrin (ED-β-CD). Under the optimum conditions, a good linearity was achieved with correlation coefficients from 0.9989 to 0.9992. The detection limits and the quantitation limits ranged from 0.63 to 0.98μg/mL and from 2.08 to 3.28μg/mL, respectively. Excellent accuracy and precision were obtained. Recoveries of the analytes varied from 97.1 to 103.2%. This method was suitable for the quantitative determination of these alkaloids in the stem with hook of Uncaria rhynchophylla and the formulations of Uncaria rhynchophylla. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A facile and flexible process of β-cyclodextrin grafted on Fe3O4 magnetic nanoparticles and host-guest inclusion studies

    International Nuclear Information System (INIS)

    Zhu Jie; He Jiang; Du Xiaoyan; Lu Ruihua; Huang Lizhen; Ge Xia

    2011-01-01

    In this study, a kind of novel surface-functionalized magnetic nanoparticles was fabricated by the Fe 3 O 4 nanoparticles surface modification with mono-6-deoxy-6-(p-tolylsulfonyl)-cyclodextrin (6-TsO-β-CD), which were employed to interact with uric acid and their behavior was investigated by electrochemical methods. The architecture has been characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA), which confirmed that cyclodextrins have been effectively functionalized on the surface of Fe 3 O 4 nanoparticles. The analyses of vibration sample magnetometer (VSM) verified that the nanoparticles owned good magnetic property. The grafted β-cyclodextrin on the Fe3O4 nanoparticles contributed to as a modified electrode for detecting uric acid with cyclic voltammograms. Electrochemical results revealed that the new materials could exhibit excellent molecules recognition ability and show high electrochemical response. The new nanoparticles simultaneously had unique properties of magnetic nanoparticles and cyclodextrins through combining their individual distinct advantages.

  9. Antimicrobial coatings on polyethylene terephthalate based on curcumin/cyclodextrin complex embedded in a multilayer polyelectrolyte architecture.

    Science.gov (United States)

    Shlar, Ilya; Droby, Samir; Rodov, Victor

    2018-04-01

    Bacterial contamination is a growing concern worldwide. The aim of this work was to develop an antimicrobial coating based on curcumin-cyclodextrin inclusion complex and using polyethylene terephthalate (PET) film as a support matrix. After a pre-treatment aimed to provide sufficient electric charge to the PET surface, it was electrostatically coated with repeated multilayers comprising alternately deposited positively-charged poly-l-lysine (PLL) and negatively-charged poly-l-glutamic acid (PLGA) and carboxymethyl-β-cyclodextrin (CMBCD). The coatings had an architecture (PLL-PLGA) 6 -(PLL-PLGA-PLL-CMBCD) n , with the number of repeated multilayers n varying from 5 to 20. The CMBCD molecules were either covalently cross-linked using carbodiimide crosslinker chemistry or left unbound. The surface morphology, structure and elemental composition of the coatings were analysed by scanning electron microscopy and energy dispersive x-ray spectroscopy. To impart antimicrobial properties to the coatings they were loaded with a natural phenolic compound curcumin forming inclusion complexes with β-cyclodextrin. The non-cross-linked coatings showed bactericidal activity towards Escherichia coli in the dark, and this activity was further enhanced upon illumination with white light. Curcumin was released from the non-cross-linked coatings into an aqueous medium in the form of cyclodextrin inclusion complex. After the cross-linking, the coating lost its dark antimicrobial activity but retained the photodynamic properties. Stabilized cross-linked curcumin-loaded coatings can serve a basis for developing photoactivated antimicrobial surfaces controlling bacterial contamination and spread. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Sorption of Ochratoxin A from aqueous solutions using beta-cyclodextrin-polyurethane polymer

    Science.gov (United States)

    The ability of a cyclodextrin-polyurethane polymer to remove ochratoxin A from aqueous solutions, including wine, was examined by batch rebinding assays and equilibrium sorption isotherms. The results were fit to two parameter models. Freundlich analysis of the sorption isotherm indicates the polyme...

  11. Reassessment of acarbose as a transition state analogue inhibitor of cyclodextrin glycosyltransferase

    NARCIS (Netherlands)

    Mosi, Renee; Sham, Howard; Uitdehaag, Joost C.M.; Ruiterkamp, Richard; Dijkstra, Bauke W.; Withers, Stephen G.

    1998-01-01

    The binding of several different active site mutants of Bacillus circulans cyclodextrin,glycosyltransferase to the inhibitor acarbose has been investigated through measurement of Ki values. The mutations represent several key amino acid positions, most of which are believed to play important roles

  12. Synthesis of C3-symmetric tri(alkylamino) guests and their interaction with cyclodextrins

    Czech Academy of Sciences Publication Activity Database

    Bednaříková, T.; Tošner, Z.; Horský, Jiří; Jindřich, J.

    2015-01-01

    Roč. 81, 1-2 (2015), s. 141-152 ISSN 0923-0750 Institutional support: RVO:61389013 Keywords : cyclodextrin * supramolecular interactions * C3-symmetric guests Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.253, year: 2015

  13. Cyclodextrin--piroxicam inclusion complexes: analyses by mass spectrometry and molecular modelling

    Science.gov (United States)

    Gallagher, Richard T.; Ball, Christopher P.; Gatehouse, Deborah R.; Gates, Paul J.; Lobell, Mario; Derrick, Peter J.

    1997-11-01

    Mass spectrometry has been used to investigate the natures of non-covalent complexes formed between the anti-inflammatory drug piroxicam and [alpha]-, [beta]- and [gamma]-cyclodextrins. Energies of these complexes have been calculated by means of molecular modelling. There is a correlation between peak intensities in the mass spectra and the calculated energies.

  14. Preparation and physico-chemical characterization of inclusion complexes between local anesthetics and hydroxypropyl-β-cyclodextrin

    International Nuclear Information System (INIS)

    Moraes, Carolina Morales; Abrami, Priscila; Goncalves, Marcos Moises; Andreo Filho, Newton; Fernandes, Sergio Antonio; Paula, Eneida de; Fraceto, Leonardo Fernandes

    2007-01-01

    S(-) Bupivacaine (S(-)BVC) and Lidocaine (LDC) are widely used local anesthetics (LA). Hydroxypropyl β-cyclodextrin (HP-β-CD) is used as a drug-carrier system. The aim of this work was to characterize inclusion complexes between LA and HP-β-CD. The affinity constants determined at different pHs show favourable complexation. The release kinetics experiments showed that S(-)BVC and LDC changed the released profiles in the presence of HP-β-CD. Nuclear magnetic resonance experiments gave information about the interaction between LA and the cyclodextrin cavity. This study focused on the physicochemical characterization of drug-delivery formulations that come out as potentially new therapeutic options for pain treatment. (author)

  15. Characterisation of Catfish (Clarias Batrachus) Oil: β-Cyclodextrin Inclusion Complex

    International Nuclear Information System (INIS)

    Zaibunnisa Abdul Haiyee; Nor Izzatul Adyani Yahya; Norizzah Abd Rashid; Dzulkifly Mat Hashim

    2016-01-01

    Catfish is a cheap source of essential omega-3 fatty acids especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Catfish oil was extracted and clean-up using pressurised liquid extraction (PLE) from the viscera of catfish (Clarias batrachus). However, the characteristics of catfish oils are sticky, strong fishy odour and can easily be oxidised with short shelf-life. In this study, catfish oil was converted into powder by formation of inclusion complex with β-cyclodextrin. Inclusion complex was prepared by using co-precipitation and kneading methods and compared with physical mixture. The inclusion complex formed were characterised by using field emission scanning electron microscopy (FESEM), differential scanning calorimeter (DSC) and fourier transform infrared spectroscopy (FTIR). FESEM images revealed that inclusion complex using co-precipitation and kneading methods has smaller in crystal sizes and appeared as different morphology compared to physical mixture. DSC proved that co-precipitation method was able to form new solid phase due to shifting of melting point to higher temperature (145.22 degree Celcius). FTIR supported the result by proving strengthening of carbonyl group (C=O). Therefore, co-precipitation method was able to successfully produce inclusion complex of catfish oil, β-cyclodextrin. (author)

  16. Novel magnetic nanoparticles coated by benzene- and β-cyclodextrin-bearing dextran, and the sorption of polycyclic aromatic hydrocarbon

    DEFF Research Database (Denmark)

    Cho, Eunae; Tahir, Muhammad Nazir; Min Choi, Jae

    2015-01-01

    We present the synthesis of novel magnetic nanoparticles functionalized by benzene- and β-cyclodextrin-derivatized dextran. The grafting strategy was based on the [alkynyl-iron] cluster in the modified dextrans, which were prepared by click reaction from alkyne-modified dextran and benzyl azide......, the potential for removing polycyclic aromatic hydrocarbons such as phenanthrene and pyrene by sorption onto the nanomaterials was assessed. In the sorption, pi-stacking interactions of the benzene-derivatized dextran and host–guest chemistry of the β-cyclodextrin-derivatized dextran were considered...

  17. Sugar-Decorated Sugar Vesicles : Lectin-Carbohydrate Recognition at the Surface of Cyclodextrin Vesicles

    NARCIS (Netherlands)

    Voskuhl, Jens; Stuart, Marc C. A.; Ravoo, Bart Jan

    2010-01-01

    An artificial glycocalix self-assembles when unilamellar bilayer vesicles of amphiphilic beta-cyclodextrins are decorated with maltose and lactose by host-guest interactions. To this end, maltose and lactose were conjugated with adamantane through a tetra(ethyleneglycol) spacer. Both

  18. Relationship between Fe2+ Ca2+ ions and cyclodextrin in olive trees infected with sooty mold

    International Nuclear Information System (INIS)

    Aragão, P H A; Andrade, C G T J; Ota, A T; Costa, M F

    2012-01-01

    In this work, Energy Dispersive X-ray Fluorescence (EDXRF) was used to observe the peak areas of chemical elements present in healthy and infected samples and a Scanning Electron Microscopy (SEM) to study the damage caused by sooty mold on olive tree leaves from the Mediterranean. Leaves infected with sooty mold presented a high concentration of Fe 2+ and a low concentration of Ca 2+ . Our results show that the infected leaves cause a metabolic imbalance in the plants due to an anomalous behavior of macronutrients and micronutrients. Infected leaves start to develop a thin layer of glucose (Cyclodextrin) on their surface. Cyclodextrin (CD) molecules are oligosaccharides consisting of α-D-glucopyranose units linked to glucosides. The most common is β-cyclodextrin (β-CD), which has seven units of α-D-glucopyranose. There are different CDs which are widely used as molecular reactors. In this work, some connections between CD molecules conformations that were obtained in order to observe the relationship of Fe 2+ and Ca 2+ in the olive tree infected with sooty mold were studied. The results are discussed in terms of number of ions found inside and outside the cavity formed by the CD molecules.

  19. Electrospinning of functional poly(methyl methacrylate) nanofibers containing cyclodextrin-menthol inclusion complexes

    International Nuclear Information System (INIS)

    Uyar, Tamer; Besenbacher, Flemming; Nur, Yusuf; Hacaloglu, Jale

    2009-01-01

    Electrospinning of nanofibers with cyclodextrin inclusion complexes (CD-ICs) is particularly attractive since distinct properties can be obtained by combining the nanofibers with specific functions of the CD-ICs. Here we report on the electrospinning of poly(methyl methacrylate) (PMMA) nanofibers containing cyclodextrin-menthol inclusion complexes (CD-menthol-ICs). These CD-menthol-IC functionalized nanofibers were developed with the purpose of producing functional nanofibers that contain fragrances/flavors with high temperature stability, and menthol was used as a model fragrance/flavor material. The PMMA nanofibers were electrospun with CD-menthol-ICs using three type of CD: α-CD, β-CD, and γ-CD. Direct pyrolysis mass spectrometry (DP-MS) studies showed that the thermal evaporation of menthol occurred over a very high and a broad temperature range (100-355 deg. C) for PMMA/CDmenthol-IC nanowebs, demonstrating the complexation of menthol with the CD cavity and its high temperature stability. Furthermore, as the size of CD cavity increased in the order α-CD β-CD>α-CD.

  20. Molecular dynamics simulation of cyclodextrin aggregation and extraction of Anthracene from non-aqueous liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xinzhe [Shenzhen Key Laboratory for Coastal Ocean Dynamic and Environment, Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); School of Environment, Tsinghua University, Beijing 100084 (China); Wu, Guozhong [Shenzhen Key Laboratory for Coastal Ocean Dynamic and Environment, Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Chen, Daoyi, E-mail: chen.daoyi@sz.tsinghua.edu.cn [Shenzhen Key Laboratory for Coastal Ocean Dynamic and Environment, Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China)

    2016-12-15

    Cyclodextrin (CD) extraction is widely used for the remediation of polycyclic aromatic hydrocarbons (PAH) pollution, but it remains unclear about the influence of CD aggregation on the PAH transport from non-aqueous liquid phase to water. The atomistic adsorption and complexation of PAHs (32 anthracenes) by CD aggregates (48 β-cyclodextrins) were studied by molecular dynamics simulations at hundreds of nanoseconds time scale. Results indicated that high temperature promoted the βCD aggregation in bulk oil, which was not found in bulk water. Nevertheless, the fractions of anthracenes entrapped inside the βCDs cavity in both scenarios were significantly increased when temperature increased from 298 to 328 K. Free energy calculation for the sub-steps of CD extraction demonstrated that the anthracenes could be extracted when the βCDs arrived at the water-oil interface or after the βCDs entered the bulk oil. The former was kinetic-controlled while the latter was thermodynamic-limited process. Results also highlighted the formation of porous structures by CD aggregates in water, which was able to sequestrate PAH clusters with the size obviously larger than the cavity diameter of individual CD. This provided an opportunity for the extraction of recalcitrant PAHs with molecular size larger than anthracenes by cyclodextrins.

  1. Preparation, characterization and in vitro evaluation of a new nucleotide analogue prodrug cyclodextrin inclusion complexes.

    Science.gov (United States)

    Diab, Roudayna; Jordheim, Lars P; Degobert, Ghania; Peyrottes, Suzanne; Périgaud, Christian; Dumontet, Charles; Fessi, Hatem

    2009-01-01

    Bis(tbutyl-S-acyl-2-thioethyl)-cytidine monophosophate is a new cytotoxic mononucleotide prodrug which have been developed to reverse the cellular resistance to nucleoside analogues. Unfortunately, its in vivo utilisation was hampered by its poor water solubility, raising the need of a molecular vector capable to mask its physicochemical characteristics although without affecting its cytotoxic activity. Hydroxypropyl-beta-cyclodextrin was used to prepare the prodrug inclusion complexes, allowing it to be solubilized in water and hence to be used for in vitro and in vivo experiments. A molar ratio of the cyclodextrin: prodrug of 3 was sufficient to obtain complete solubilization of the prodrug. The inclusion complex was characterized by differential scanning calorimetry, which revealed the disappearance of the melting peak of the prodrug suggesting the formation of inclusion complex. Proton Nuclear Magnetic Resonance spectroscopy provided a definitive proof of the inclusion complex formation, which was evidenced by the large chemical shift displacements observed for protons located in the interior of the hydrophobic cyclodextrin cavity. The complex retained its cytotoxic activity as shown by in vitro cell survival assays on murine leukemia cells. These results provided a basis for potential therapeutic applications of co-formulation of this new nucleotide analogue with hydroxypropyl-beta-CD in cancer therapy.

  2. Selectivity in capillary electrophoresis:  application to chiral separations with cyclodextrins.

    Science.gov (United States)

    Lelièvre, F; Gareil, P; Jardy, A

    1997-02-01

    In order to accurately evaluate the performances of any electrolyte medium, a clear concept of selectivity in capillary electrophoresis and related electroseparation techniques is proposed. Selectivity is defined as the ratio of the affinity factors of both analytes for a separating agent (phase, pseudophase, or complexing agent present in the background electrolyte). When in the presence of a complexing agent and if only 1:1 complexation occurs, selectivity corresponds to the ratio of the apparent binding constants and is independent of the concentration of the complexing agent. This concept is illustrated through the separations of neutral and anionic enantiomers in the presence of a cationic cyclodextrin, the mono(6-amino-6-deoxy)-β-cyclodextrin, as a chiral complexing agent. The values obtained for different pairs of enantiomers are discussed with regard to the functional groups that distinguish them. When the analytes have the same mobilities in free solution and in their complexed form, then the resolution equation developed in micellar electrokinetic chromatography may be applied and optimum conditions (affinity factors, chiral agent concentration) can be predicted.

  3. A new technique for promoting cyclic utilization of cyclodextrins in biotransformation.

    Science.gov (United States)

    Shen, Yanbing; Yu, Ziqi; Yang, Xu; Wang, Fang; Luo, Jianmei; Wang, Min

    2017-01-01

    Cyclodextrins (CDs) can improve the productivity of steroid biotransformation by enhancing substrate solubility. CDs can be recycled by grafting them with appropriate carriers. Loofah fiber is an excellent grafting material for CDs, and can be applied to the biotransformation and recycling of β-cyclodextrin (β-CD). In this work, a technique for recycling β-CD in cortisone acetate (CA) biotransformation by Arthrobacter simplex CPCC 140451 was studied. Loofah fiber-grafted β-CD (LF-β-CD) was prepared using epichlorohydrin, which is a cross-linking agent. The grafting yield of β-CD was 74.8 mg g -1 dried fibers. LF-β-CD could increase the solubility of CA and enhance biotransformation. The initial conversion rate of CA was 1.5-fold higher than that of the blank group. LF-β-CD was also used in biocatalytic reactions for eight cycles, and it maintained the conversion ratio of CA at approximately 90%. Given the above positive results, LF-β-CD can be utilized in biotechnological recycling applications. This method can also be applied to CD derivatives and hydrophobic compounds.

  4. Ca{sup 2+} ion sensing by a piperidin-4-one derivative and the effect of β-cyclodextrin complexation on the sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sumithra, M.; Sivaraj, R.; Selvan, G. Tamil; Selvakumar, P. Mosae; Enoch, Israel V.M.V., E-mail: drisraelenoch@gmail.com

    2017-05-15

    In this paper, we report the turn-on fluorescence based Ca{sup 2+} ion sensing by an anthracene piperidin-4-one derivative. The compound is obtained using a simple two step synthesis. The compound is characterized using NMR and mass spectral methods. The host-guest complex formation of the compound with β-cyclodextrin is prepared and characterized using fluorescence and 2D ROESY spectroscopy. The compound forms the inclusion complex with a 1:1 stoichiometry. The structure of the host-guest complex is proposed. The Ca{sup 2+} ion selectivity of the compound in its free form and cyclodextrin-bound forms are studied. In both the forms, the piperidin-4-one derivative senses Ca{sup 2+} and in the case of the cyclodextrin encapsulated form it shows a better competitive binding of Ca{sup 2+} in the presence of other metal ions. - Highlights: •An anthracene iminoderivative of 3-methyl-2,6-diphenylpiperidin-4-one is synthesized. •The anthracene moiety of the compound is encapsulated by β-Cyclodextrin. •The compound senses Ca{sup 2+} ion both in water and β-CD media. •β-CD molecule does not interrupt the Ca{sup 2+} ion binding.

  5. Solid-state flurbiprofen and methyl-β-cyclodextrin inclusion complexes prepared using a single-step, organic solvent-free supercritical fluid process.

    Science.gov (United States)

    Rudrangi, Shashi Ravi Suman; Kaialy, Waseem; Ghori, Muhammad U; Trivedi, Vivek; Snowden, Martin J; Alexander, Bruce David

    2016-07-01

    The aim of this study was to enhance the apparent solubility and dissolution properties of flurbiprofen through inclusion complexation with cyclodextrins. Especially, the efficacy of supercritical fluid technology as a preparative technique for the preparation of flurbiprofen-methyl-β-cyclodextrin inclusion complexes was evaluated. The complexes were prepared by supercritical carbon dioxide processing and were evaluated by solubility, differential scanning calorimetry, X-ray powder diffraction, scanning electron microscopy, practical yield, drug content estimation and in vitro dissolution studies. Computational molecular docking studies were conducted to study the possibility of molecular arrangement of inclusion complexes between flurbiprofen and methyl-β-cyclodextrin. The studies support the formation of stable molecular inclusion complexes between the drug and cyclodextrin in a 1:1 stoichiometry. In vitro dissolution studies showed that the dissolution properties of flurbiprofen were significantly enhanced by the binary mixtures prepared by supercritical carbon dioxide processing. The amount of flurbiprofen dissolved into solution alone was very low with 1.11±0.09% dissolving at the end of 60min, while the binary mixtures processed by supercritical carbon dioxide at 45°C and 200bar released 99.39±2.34% of the drug at the end of 30min. All the binary mixtures processed by supercritical carbon dioxide at 45°C exhibited a drug release of more than 80% within the first 10min irrespective of the pressure employed. The study demonstrated the single step, organic solvent-free supercritical carbon dioxide process as a promising approach for the preparation of inclusion complexes between flurbiprofen and methyl-β-cyclodextrin in solid-state. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Osteogenic activity of cyclodextrin-encapsulated doxycycline in a calcium phosphate PCL and PLGA composite

    Energy Technology Data Exchange (ETDEWEB)

    Trajano, V.C.C.; Costa, K.J.R. [Restorative Dentistry Department, Faculty of Dentistry, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, CEP: 31270-901 Belo Horizonte, Minas Gerais (Brazil); Lanza, C.R.M. [Department of Oral Clinical, Surgery and Pathology, Faculty of Dentistry, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, CEP: 31270-901 Belo Horizonte, Minas Gerais (Brazil); Sinisterra, R.D. [Chemistry Department, ICEX, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, CEP: 31270-901 Belo Horizonte, Minas Gerais (Brazil); Cortés, M.E., E-mail: mecortes@ufmg.br [Restorative Dentistry Department, Faculty of Dentistry, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, CEP: 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2016-07-01

    Composites of biodegradable polymers and calcium phosphate are bioactive and flexible, and have been proposed for use in tissue engineering and bone regeneration. When associated with the broad-spectrum antibiotic doxycycline (DOX), they could favor antimicrobial action and enhance the action of osteogenic composites. Composites of polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and a bioceramic of biphasic calcium phosphate Osteosynt® (BCP) were loaded with DOX encapsulated in β-cyclodextrin (βCD) and were evaluated for effects on osteoblastic cell cultures. The DOX/βCD composite was prepared with a double mixing method. Osteoblast viability was assessed with methyl tetrazolium (MTT) assays after 1 day, 7 day, and 14 days of composite exposure; alkaline phosphatase (AP) activity and collagen production were evaluated after 7 days and 14 days, and mineral nodule formation after 14 days. Composite structures were evaluated by scanning electron microscopy (SEM). Osteoblasts exposed to the composite containing 25 μg/mL DOX/βCD had increased cell proliferation (p < 0.05) compared to control osteoblast cultures at all experimental time points, reaching a maximum in the second week. AP activity and collagen secretion levels were also elevated in osteoblasts exposed to the DOX/βCD composite (p < 0.05 vs. controls) and reached a maximum after 14 days. These results were corroborated by Von Kossa test results, which showed strong formation of mineralization nodules during the same time period. SEM of the composite material revealed a surface topography with pore sizes suitable for growing osteoblasts. Together, these results suggest that osteoblasts are viable, proliferative, and osteogenic in the presence of a DOX/βCD-containing BCP ceramic composite. - Highlights: • Doxycycline encapsulated in β-cyclodextrin was incorpored into a polycaprolactone - poly(lactic-co-glycolic acid) - calcium phosphate • Composite’s scaffold carrying doxycycline-β-cyclodextrin

  7. Supramolecular structure of glibenclamide and β-cyclodextrins complexes.

    Science.gov (United States)

    Lucio, David; Irache, Juan Manuel; Font, María; Martínez-Ohárriz, María Cristina

    2017-09-15

    Glibenclamide is an antidiabetic drug showing low bioavailability as consequence of its low solubility. To solve this drawback, the interaction with cyclodextrins has been proposed. The formation of GB-βCDs inclusion complexes was carried out using different methods, βCD derivatives and drug-to-cyclodextrin ratios. The structures of the corresponding complexes have been studied by molecular modelling, X-ray diffraction and differential thermal analysis. The dissolution behavior of inclusion complexes has been compared to that of pure GB. Dimeric inclusion complexes were obtained with different CD disposals, head-to-head for βCD and head-to-tail for HPβCD and RMβCD. Amorphous inclusion complexes were obtained by employing methods of freeze-drying or coevaporation in ammonia-water. However, crystalline structures were formed by kneading and coevaporation in ethanol/water in the case of GB-βCD complexes. The arrangement of these structures depended on the GB:βCD ratio, yielding cage type structures for 1:3 and 1:5 ratios and channel-type structures for higher GB contents. The amount of GB released and its dissolution rate was considerably increased by the use of amorphous inclusion complexes; whereas, slower GB release rates were found from crystalline inclusion complexes formed by kneading or coevaporation in ethanol/water. In addition, it was found that the porous structure strongly conditioned the GB dissolution rate from crystalline products. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Subchronic (13-week) oral toxicity study of α-cyclodextrin in dogs

    NARCIS (Netherlands)

    Lina, B.A.R.; Bär, A.

    2004-01-01

    The oral toxicity of α-cyclodextrin (α-CD) was examined in a 13-week feeding study in which groups of Beagle dogs received α-CD in the diet at concentrations of 0 (control), 5, 10, or 20% (4dogs/sex/group). No treatment-related changes were noted in behavior or appearance of the dogs and no

  9. Subchronic (13-week) oral toxicity study of y-cyclodextrin in dogs

    NARCIS (Netherlands)

    Til, H.P.; Bär, A.

    1998-01-01

    The oral toxicity of γ-cyclodextrin (γ- CD) was examined in a 13-week feeding study in which four groups of four male and four female Beagle dogs received γ-CD in the diet at concentrations of 0 (control), 5, 10, or 20%. No treatment-related changes were noted in behavior or appearance of the dogs

  10. Preparation of Hydroxypropyl-β-cyclodextrin Cross-linked Multi-walled Carbon Nanotubes and Their Application in Enantioseparation of Clenbuterol

    Institute of Scientific and Technical Information of China (English)

    Yu Jingang; Huang Dushu; Huang Kelong; Hong Yong

    2011-01-01

    A method of cross-linking multi-walled carbon nanotubes by a nucleophilic substitution of brominated multi-walled carbon nanotubes using hydroxypropyl-β-cyclodextrin anions was studied. The modified multi-walled carbon nanotube samples were characterized using thermogravimetric analysis, energy-dispersive X-ray spectros-copy, transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and Fourier transform infrared spectroscopy. The hydroxypropyi-β-cyclodextrin modified multi-walled carbon nanotubes were used as a chiral stationary phase additive for thin-layer chromatography to separate clenbuterol enantiomers, and the chiral separation factor was increased.

  11. Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants.

    Science.gov (United States)

    Agócs, Tamás Zoltán; Puskás, István; Varga, Erzsébet; Molnár, Mónika; Fenyvesi, Éva

    2016-01-01

    Advanced oxidation processes (AOPs) are considered highly competitive water treatment technologies for the removal of organic pollutants. Among AOP techniques, photocatalysis has recently been the most widely studied. Our aims were to investigate how the dispersion of nanosized titanium dioxide (nanoTiO 2 ) applied in photodegradation-based procedures can be stabilized with cyclodextrins in order to obtain a new, more efficient photocatalyst for the purification of waters polluted by xenobiotics applying UV irradiation. During our work, on the one hand, we studied the behavior and stability of nanoTiO 2 in cyclodextrin solutions. On the other hand, we used various monomer and polymer cyclodextrin derivatives, and assessed the options for nanoTiO 2 stabilization in the presence of various salts and tap water on the basis of turbidity tests. The physical stability of nanoTiO 2 dispersions is diminished in the presence of the salts found in tap water (and occurring also in surface waters and ground water) and they are precipitated immediately. This colloidal instability can be improved by cyclodextrin derivatives. Based on the results of our studies we have selected carboxymethyl β-cyclodextrin polymer (CMBCD-P) for stabilization of nanoTiO 2 dispersions. The photocatalytic degradation of methylene blue and ibuprofen as model organic pollutants in various media (distilled water, NaCl solution and tap water) has been studied using nanoTiO 2 as catalyst stabilized by CMBCD-P. CMBCD-P itself showed a catalytic effect on the UV degradation of methylene blue. In addition to enhancing the colloid stability of nanoTiO 2 CMBCD-P showed also synergistic effects in catalyzing the photodecomposition process of the dye. On the other hand, ibuprofen as a model pharmaceutical, a pollutant of emerging concern (EP), was protected by CMBCD-P against the photocatalytic degradation showing that inclusion complex formation can result in opposite effects depending on the structure of the

  12. Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants

    Directory of Open Access Journals (Sweden)

    Tamás Zoltán Agócs

    2016-12-01

    Full Text Available Advanced oxidation processes (AOPs are considered highly competitive water treatment technologies for the removal of organic pollutants. Among AOP techniques, photocatalysis has recently been the most widely studied. Our aims were to investigate how the dispersion of nanosized titanium dioxide (nanoTiO2 applied in photodegradation-based procedures can be stabilized with cyclodextrins in order to obtain a new, more efficient photocatalyst for the purification of waters polluted by xenobiotics applying UV irradiation. During our work, on the one hand, we studied the behavior and stability of nanoTiO2 in cyclodextrin solutions. On the other hand, we used various monomer and polymer cyclodextrin derivatives, and assessed the options for nanoTiO2 stabilization in the presence of various salts and tap water on the basis of turbidity tests. The physical stability of nanoTiO2 dispersions is diminished in the presence of the salts found in tap water (and occurring also in surface waters and ground water and they are precipitated immediately. This colloidal instability can be improved by cyclodextrin derivatives. Based on the results of our studies we have selected carboxymethyl β-cyclodextrin polymer (CMBCD-P for stabilization of nanoTiO2 dispersions. The photocatalytic degradation of methylene blue and ibuprofen as model organic pollutants in various media (distilled water, NaCl solution and tap water has been studied using nanoTiO2 as catalyst stabilized by CMBCD-P. CMBCD-P itself showed a catalytic effect on the UV degradation of methylene blue. In addition to enhancing the colloid stability of nanoTiO2 CMBCD-P showed also synergistic effects in catalyzing the photodecomposition process of the dye. On the other hand, ibuprofen as a model pharmaceutical, a pollutant of emerging concern (EP, was protected by CMBCD-P against the photocatalytic degradation showing that inclusion complex formation can result in opposite effects depending on the structure

  13. Mechanochemical Preparation of Stable Sub-100 nm γ-Cyclodextrin:Buckminsterfullerene (C60) Nanoparticles by Electrostatic or Steric Stabilization.

    Science.gov (United States)

    Van Guyse, Joachim F R; de la Rosa, Victor R; Hoogenboom, Richard

    2018-02-21

    Buckminster fullerene (C 60 )'s main hurdle to enter the field of biomedicine is its low bioavailability, which results from its extremely low water solubility. A well-known approach to increase the water solubility of C 60 is by complexation with γ-cyclodextrins. However, the formed complexes are not stable in time as they rapidly aggregate and eventually precipitate due to attractive intermolecular forces, a common problem in inclusion complexes of cyclodextrins. In this study we attempt to overcome the attractive intermolecular forces between the complexes by designing custom γ-cyclodextrin (γCD)-based supramolecular hosts for C 60 that inhibit the aggregation found in native γCD-C 60 complexes. The approach entails the introduction of either repulsive electrostatic forces or increased steric hindrance to prevent aggregation, thus enhancing the biomedical application potential of C 60 . These modifications have led to new sub-100 nm nanostructures that show long-term stability in solution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Per-2,3-O-alkylated beta-cyclodextrin duplexes connected with disulfide bonds

    Czech Academy of Sciences Publication Activity Database

    Tatar, Ameneh; Grishina, Anastasia; Buděšínský, Miloš; Kraus, Tomáš

    2017-01-01

    Roč. 29, č. 1 (2017), s. 40-48 ISSN 1061-0278 R&D Projects: GA MŠk LD12019 Grant - others:COST(XE) CM1005 Institutional support: RVO:61388963 Keywords : cyclodextrins * inclusion complexes * disulfide bonds Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 1.264, year: 2016

  15. Host-Guest Complexes of Cyclodextrins and Nanodiamonds as a Strong Non-Covalent Binding Motif for Self-Assembled Nanomaterials.

    Science.gov (United States)

    Schibilla, Frauke; Voskuhl, Jens; Fokina, Natalie A; Dahl, Jeremy E P; Schreiner, Peter R; Ravoo, Bart Jan

    2017-11-13

    We report the inclusion of carboxy- and amine-substituted molecular nanodiamonds (NDs) adamantane, diamantane, and triamantane by β-cyclodextrin and γ-cyclodextrin (β-CD and γ-CD), which have particularly well-suited hydrophobicity and symmetry for an optimal fit of the host and guest molecules. We studied the host-guest interactions in detail and generally observed 1:1 association of the NDs with the larger γ-CD cavity, but observed 1:2 association for the largest ND in the series (triamantane) with β-CD. We found higher binding affinities for carboxy-substituted NDs than for amine-substituted NDs. Additionally, cyclodextrin vesicles (CDVs) were decorated with d-mannose by using adamantane, diamantane, and triamantane as non-covalent anchors, and the resulting vesicles were compared with the lectin concanavalin A in agglutination experiments. Agglutination was directly correlated to the host-guest association: adamantane showed lower agglutination than di- or triamantane with β-CDV and almost no agglutination with γ-CDV, whereas high agglutination was observed for di- and triamantane with γ-CDV. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Effect of cyclodextrins on pH-induced conformational transition of poly(methacrylic acid)

    Czech Academy of Sciences Publication Activity Database

    Horský, Jiří; Podešva, Jiří; Walterová, Zuzana

    2011-01-01

    Roč. 65, č. 6 (2011), s. 847-854 ISSN 0366-6352 R&D Projects: GA ČR GA202/09/2078 Institutional research plan: CEZ:AV0Z40500505 Keywords : cyclodextrins * inclusion complexes * polyelectrolytes Subject RIV: BO - Biophysics Impact factor: 1.096, year: 2011

  17. Use of hydroxypropyl-beta-cyclodextrin ad polymer matrix for formation of inclusion complex with drug nifedipine

    International Nuclear Information System (INIS)

    Carneiro, Elisa F.; Araujo, Marcia V.G. de; Barbosa, Ronilson V.; Silva, Caroline W.P. da; Barisson, Andersson; Zawadzki, Sonia F.; Andrade, George Ricardo S.; Costa Junior, Nivan B. da

    2009-01-01

    In this work it was prepared and characterized an inclusion complex between the polymeric matrix hydroxypropyl-beta cyclodextrin and nifedipine, a hydrophobic drug calcium antagonistic, used for the cardiovascular diseases treatment. The study of the phase- solubility diagram showed an increase of the aqueous solubility of the drug after inclusion, was observed and The differential scanning calorimetry analysis did not show the melting point temperature of the drug in the formed complex. This fact is considered as an evidence of the encapsulation process. 1 H NMR studies suggested that the non-aromatic ring of the nifedipine would be inserted in the cavity of the hydroxypropyl-beta-cyclodextrin.This orientation was also proposed by the used molecular modelling methods. (author)

  18. Carborane-beta-cyclodextrin complexes as a supramolecular connector for bioactive surfaces

    Czech Academy of Sciences Publication Activity Database

    Neirynck, P.; Schimer, Jiří; Jonkheijm, P.; Milroy, L. G.; Cígler, Petr; Brunsveld, L.

    2015-01-01

    Roč. 3, č. 4 (2015), s. 539-545 ISSN 2050-750X R&D Projects: GA MŠk(CZ) LH11027 Institutional support: RVO:61388963 Keywords : beta-cyclodextrine/carborane host-guest system * supramolecular chemistry * bioactive surfaces Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.872, year: 2015 http://pubs.rsc.org/en/content/articlepdf/2015/tb/c4tb01489h

  19. Disposition of [14C]γ-cyclodextrin in germ-free and conventional rats

    NARCIS (Netherlands)

    Bie, A.T.H.J. de; Ommen, B. van; Bär, A.

    1998-01-01

    The absorption, disposition, metabolism, and excretion of 14C-labeled γ-cyclodextrin ([14C]γ-CD) was examined in four separate experiments with Wistar rats. In experiment 1, [14C]γ-CD (25 μCi, 600 mg/kg body wt) was administered intravenously to four male and four female conventional rats. In

  20. Disposition of 14C-α-cyclodextrin in germ-free and conventional rats

    NARCIS (Netherlands)

    Ommen, B. van; Bie, A.T.H.J. de; Bär, A.

    2004-01-01

    The absorption, disposition, metabolism, and excretion of uniformly 14C-labeled α-cyclodextrin (14C-α-CD) was examined in four separate experiments with Wistar rats. In Experiment 1, 14C-α-CD (25μCi, 50mg/kg bw) was administered intravenously to four male and four female conventional rats. In

  1. Preparation of β-cyclodextrin-gold nanoparticles modified open tubular column for capillary electrochromatographic separation of chiral drugs.

    Science.gov (United States)

    Zhou, Li; Jiang, Shenmeng; Zhang, Xue; Fang, Linlin; Guo, Xingjie

    2018-04-01

    In this paper, β-cyclodextrin (β-CD) modified gold nanoparticles (AuNPs) coated open tubular column (OT column) was prepared for capillary electrochromatography. The open tubular column was constructed through self-assembly of gold nanoparticles on 3-mercaptopropyl-trimethoxysilane (MPTMS) prederivatized capillary and subsequent modification of thiols β-cyclodextrin (SH-β-CD). Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultraviolet visible spectroscopy were carried out to characterize the prepared open tubular column and synthesized gold nanoparticles. By comparing different coating times of gold nanoparticles and thiols β-cyclodextrin, we got the optimal conditions for preparing the open tubular column. Also, the separation parameters were optimized including buffer pH, buffer concentration and applied voltage. Separation effectiveness of open tubular column was verified by the separation of four pairs of drug enantiomers including bifonazole, fexofenadine, omeprazole and lansoprazole, and satisfactory separation results were achieved for these analytes studied. In addition, the column showed good stability and repeatability. The relative standard deviation values less than 5% were obtained through intra-day, inter-day, and column-to-column investigations. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Supramolecular hydrogel formation between chitosan and hydroxypropyl β-cyclodextrin via Diels-Alder reaction and its drug delivery.

    Science.gov (United States)

    Zhang, Mengke; Wang, Jinpeng; Jin, Zhengyu

    2018-07-15

    Chitosan-cyclodextrin hydrogel (CFCD) was prepared via Diels-Alder reaction between furfural functionalized chitosan (CF) and N-maleoyl alanine functionalized hydroxypropyl β-cyclodextrin (HPCD-AMI) in aqueous media without any catalyst or initiator. The CF and HPCD-AMI were confirmed by Fourier transform infrared spectroscopy and 1 H nuclear magnetic resonance spectroscopy. The resultant CFCD hydrogel was characterized in terms of thermal peripteries, microstructure, rheology behavior, and swelling capacity. The rheology analysis found that the storage modulus G' ranged from 1pa to 1200pa as the degree of furfural substitute on chitosan increased from 2.6% to 28.3%, indicating the hydrogel strength can be tuned readily by reaction stoichiometry. The swelling behaviors proved that CFCD hydrogel was pH-responsive with low swelling capacity, which would be preferable for drug delivery. Drug adsorption analysis showed the introduction of cyclodextrin into CFCD hydrogels promoted drug adsorption capacity. In addition, methyl orange cumulative release in PBS buffer was only 48.85% after 24h, suggesting CFCD hydrogel had good sustained release capacity on the loaded drug. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Biosynthesis of ketomycin. (II) biomimetic model for beta-lactamase catalysis: host-guest interactions in cyclodextrin-penicillin inclusion complex

    International Nuclear Information System (INIS)

    Mak, H.W.

    1986-01-01

    The antibiotic ketomycin is formed from shikimic acid via chorismic acid and prephenic acid. Phenylalanine and 2',5'-dihydrophenylalanine derived from shikimic acid are not intermediates in the biosynthesis. Degradation of ketomycin derived from [1,6- 14 C]shikimic acid showed that prephenic acid is converted into ketomycin with stereospecific discrimination between the two enantiotopic edges of the ring, the pro-S-R edge giving rise to the C-2', C-3' side of the cyclohexane ring of ketomycin. The resistance of pathogenic bacteria to the action of β-lactam antibiotics is mainly ascribed to their ability to produce β-lactamase to cleave the β-lactam ring. It is essential to understand the molecular nature of β-lactamase-penicillin recognition for designing and formulating more effective β-lactam antibiotics. A biomimetic study of β-lactamase is therefore initiated. To meet the requirements of hydrophobic and serine protease characteristics of β-lactamase, α-cyclodextrin is chosen as a biomimetic model for β-lactamase. The structural specificity and the chemical dynamics of α-cyclodextrin-phenoxymethyl penicillin inclusion complex in solid state and in solution have been determined by IR and NMR spectroscopy. The spectral results strongly indicate that the phenyl portion of the phenoxymethyl penicillin forms a stable inclusion complex with the hydrophobic cavity of α-cyclodextrin in solution as well as in the solid state. Kinetic studies followed by 1 HNMR and HPLC analyses under alkaline condition have shown that the α-cyclodextrin mimics the catalytic function of serine of β-lactamase in the stereospecific hydrolysis of the β-lactam ring of phenoxymethyl penicillin

  4. Computational study on the molecular inclusion of andrographolide by cyclodextrin

    Science.gov (United States)

    Zhou, Hongwei; Lai, Wai-Ping; Zhang, Zhiqiang; Li, Wai-Kee; Cheung, Hon-Yeung

    2009-03-01

    Due to the poor water solubility of andrographolide (andro), an inclusion technique has been developed to modify its physical and chemical properties so as to improve its bioavailability. In contrast with the immense experimental studies on the inclusion complexes of andro:cyclodextrin, no computational study has so far been carried out on this system. In this work, preliminary docking experiments with AutoDock were performed. Density Functional Theory (DFT) and Austin Model 1 (AM1) calculations upon the docking instances were applied to investigate the two possible modes of molecular inclusions between andro and x-cyclodextrin ( xCD, where x is α, β or γ). Atoms-in-Molecules (AIM) analysis based on the B3LYP/cc-pVDZ wavefunction was applied to verify the existence of the intermolecular hydrogen bonds. It was found that the most stable complex among the six possible inclusion complexes was the one formed between andro and βCD with andro's decalin ring moiety wrapped by CD at a ratio of 1:1. The hydrogen bonds between andro and CD were responsible for the stability of the inclusion complexes. The calculated data were found to be consistent with the experimental results. Thus, the results of this study can aid new drug design processes.

  5. INTERACTIONS OF METHYL ORANGE WITH CYCLODEXTRIN/SODIUM-MONTMORILLONITE SYSTEMS PROBED BY UV-VISIBLE SPECTROSCOPY

    Science.gov (United States)

    Clay mineral colloids play important roles in the adsorption of polar organic contaminants in the environment. Similarly, cyclodextrins (CD) can entrap poorly water-soluble organic compounds. A combination of CDs and clay minerals affords great opportunities to investigate simult...

  6. Smart DNA vectors based on cyclodextrin polymers: compaction and endosomal release.

    Science.gov (United States)

    Wintgens, Véronique; Leborgne, Christian; Baconnais, Sonia; Burckbuchler, Virginie; Le Cam, Eric; Scherman, Daniel; Kichler, Antoine; Amiel, Catherine

    2012-02-01

    Neutral β-cyclodextrin polymers (polyβCD) associated with cationic adamantyl derivatives (Ada) can be used to deliver plasmid DNA into cells. In absence of an endosomolytic agent, transfection efficiency remains low because most complexes are trapped in the endosomal compartment. We asked whether addition of an imidazole-modified Ada can increase efficiency of polyβCD/cationic Ada-based delivery system. We synthesized two adamantyl derivatives: Ada5, which has a spacer arm between the Ada moiety and a bi-cationic polar head group, and Ada6, which presents an imidazole group. Strength of association between polyβCD and Ada derivatives was evaluated by fluorimetric titration. Gel mobility shift assay, zeta potential, and dark field transmission electron microscopy experiments demonstrated the system allowed for efficient DNA compaction. In vitro transfection experiments performed on HepG2 and HEK293 cells revealed the quaternary system polyβCD/Ada5/Ada6/DNA has efficiency comparable to cationic lipid DOTAP. We successfully designed fine-tuned DNA vectors based on cyclodextrin polymers combined with two new adamantyl derivatives, leading to significant transfection associated with low toxicity.

  7. Contrasting Binding of Fisetin and daidzein in γ-Cyclodextrin Nanocavity

    OpenAIRE

    Pahari, Biswapathik; Sengupta, Bidisha; Chakraborty, Sandipan; Thomas, Briannica; McGowan, Dyffreyon; Sengupta, Pradeep K.

    2012-01-01

    Steady state and time resolved fluorescence along with anisotropy and induced circular dichroism (ICD) spectroscopy provide useful tools to observe and understand the behavior of the therapeutically important plant flavonoids fisetin and daidzein in γ-cyclodextrin (γ-CDx) nanocavity. Benesi-Hildebrand plots indicated 1:1 stoichiometry for both the supramolecular complexes. However the mode of the binding of fisetin significantly differs from daidzein in γ-CDx, as is observed from ICD spectra ...

  8. Improved bread-baking process using Saccharomyces cerevisiae displayed with engineered cyclodextrin glucanotransferase.

    Science.gov (United States)

    Shim, Jae-Hoon; Seo, Nam-Seok; Roh, Sun-Ah; Kim, Jung-Wan; Cha, Hyunju; Park, Kwan-Hwa

    2007-06-13

    A bread-baking process was developed using a potential novel enzyme, cyclodextrin glucanotransferase[3-18] (CGTase[3-18]), that had previously been engineered to have enhanced hydrolyzing activity with little cyclodextrin (CD) formation activity toward starch. CGTase[3-18] was primarily manipulated to be displayed on the cell surface of Saccharomyces cerevisiae. S. cerevisiae carrying pdeltaCGT integrated into the chromosome exhibited starch-hydrolyzing activity at the same optimal pH and temperature as the free enzyme. Volumes of the bread loaves and rice cakes prepared using S. cerevisiae/pdeltaCGT increased by 20% and 45%, respectively, with no detectable CD. Retrogradation rates of the bread and rice cakes decreased significantly during storage. In comparison to the wild type, S. cerevisiae/pdeltaCGT showed improved viability during four freeze-thaw cycles. The results indicated that CGTase[3-18] displayed on the surface of yeast hydrolyzed starch to glucose and maltose that can be used more efficiently for yeast fermentation. Therefore, display of an antistaling enzyme on the cell surface of yeast has potential for enhancing the baking process.

  9. Study on inclusion complex of cyclodextrin with methyl xanthine derivatives by fluorimetry

    Science.gov (United States)

    Wei, Yan-Li; Ding, Li-Hua; Dong, Chuan; Niu, Wei-Ping; Shuang, Shao-Min

    2003-10-01

    The inclusion complexes of β-cyclodextrin (β-CD) and HP-β-cyclodextrin (HP-β-CD) with caffeine, theophylline and theobromine were investigated by fluorimetry. Various factors affecting the formation of inclusion complexes were discussed in detail including forming time, pH effect and temperature. The results indicate that inclusion process was affected seriously by laying time and pH. The forming time of β-CD inclusion complexes is much longer than that of HP-β-CD. The optimum pH range is about 7-12 for caffeine, 8-10 for TP, 10.5-12 for TB. The intensities of their fluorescence increase with the decreasing of temperature. Their maximum excitation wavelengths are all in the range of 280-290 nm. The emission wavelength of caffeine and theophylline are both in the range of 340-360 nm, and that of theobromine is about 325 nm. The fluorescence signals are intensified with the increasing concentration of CD. The stoichiometry of the inclusion complexes of CD with these three methyl xanthine derivatives are all 1:1 and the formation constant are all calculated.

  10. Spray drying of Pomegranate Juice using maltodextrin/cyclodextrin blends as the wall material

    Science.gov (United States)

    Microencapsulation protects sensitive nutrients for preservation, masking flavors, or to enhance delivery. Ratios of maltodextrin and '-cyclodextrin (20:0, 19:1, and 17:3 % w/w) were dissolved in water and mixed with pomegranate juice for spray drying with inlet temperatures of 120, 140 and 160°C. ...

  11. Synthesis and supramolecular properties of regioisomers of mononaphthylallyl derivatives of .gamma.-cyclodextrin

    Czech Academy of Sciences Publication Activity Database

    Bláhová, M.; Filippov, Sergey K.; Kováčik, L.; Horský, Jiří; Hybelbauerová, S.; Syrová, Z.; Křížek, T.; Jindřich, J.

    2017-01-01

    Roč. 13, 27 November (2017), s. 2509-2520 ISSN 1860-5397 R&D Projects: GA ČR(CZ) GA17-07164S; GA MŠk(CZ) 7F14009 Institutional support: RVO:61389013 Keywords : gamma-cyclodextrin * naphthylallyl derivatives * regioselective alkylation Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 2.337, year: 2016

  12. α-Methylprednisolone conjugated cyclodextrin polymer-based nanoparticles for rheumatoid arthritis therapy

    Directory of Open Access Journals (Sweden)

    Jungyeon Hwang

    2008-10-01

    Full Text Available Jungyeon Hwang1, Kathleen Rodgers2, James C Oliver3, Thomas Schluep11Insert Therapeutics, Inc., Pasadena, CA, USA; 2Livingston Research Institute, Los Angeles, CA, USA; James C Oliver, Peptagen, Inc., Raleigh, NC USAAbstract: A glycinate derivative of α-methylprednisolone (MP was prepared and conjugated to a linear cyclodextrin polymer (CDP with a loading of 12.4% w/w. The polymer conjugate (CDP-MP self-assembled into nanoparticles with a size of 27 nm. Release kinetics of MP from the polymer conjugate showed a half-life (t1/2 of 50 h in phosphate buffer solution (PBS and 19 h in human plasma. In vitro, the proliferation of human lymphocytes was suppressed to a similar extent but with a delayed effect when CDP-MP was compared with free MP. In vivo, CDP-MP was administered intravenously to mice with collagen-induced arthritis and compared with free MP. CDP-MP was administered weekly for six weeks (0.07, 0.7, and 7 mg/kg/week and MP was administered daily for six weeks (0.01, 0.1, and 1 mg/kg/day. Body weight changes were minimal in all animals. After 28 days, a significant decrease in arthritis score was observed in animals treated weekly with an intermediate or high dose of CDP-MP. Additionally, dorsoplantar swelling was reduced to baseline in animals treated with CDP-MP at the intermediate and high dose level. Histological evaluation showed a reduction in synovitis, pannus formation and disruption of architecture at the highest dose level of CDP-MP. MP administered daily at equivalent cumulative doses showed minimal efficacy in this model. This study demonstrates that conjugation of MP to a cyclodextrin-polymer may improve its efficacy, leading to lower doses and less frequent administration for a safer and more convenient management of rheumatoid arthritis.Keywords: α-methylprednisolone (MP, cyclodextrin polymer (CDP, polymer conjugate (CDP-MP, rheumatoid arthritis (RA, enhanced permeability and retention effect (EPR

  13. Biointerfacial phenomena of amlodipine buccomucosal tablets of HPMC matrix system containing polyacrylate polymer/β-cyclodextrin: Correlation of swelling and drug delivery performance.

    Science.gov (United States)

    Panda, Brajabihari; Subhadarsini, Rajalaxmi; Mallick, Subrata

    2016-01-01

    This study focuses on the development of amlodipine bilayer buccal tablets of hydroxypropyl methylcellulose (HPMC) matrix system containing polyacrylate polymer (Carbopol(®))/β-cyclodextrin as the drug layer and ethylcellulose as the non-swellable backing layer, and their biointerfacial phenomena. Tablets were evaluated for swelling, erosion and mucoadhesion using buccal mucosal tissue ex vivo. In vitro drug release and ex vivo drug transport across mucosal tissue were also performed in phosphate buffer (pH 6.8). The relationship of swelling with buccoadhesion and buccal permeation of various bilayer tablet formulations containing HPMC alone and in combination with Carbopol or drug-β-cyclodextrin complex has been prepared. Overall buccoadhesion of the tablet with combination of HPMC and Carbopol was increased significantly compared with that of HPMC alone. Presence of cyclodextrin did not change bioadhesion force and swelling behavior significantly. Ex vivo permeation was increased with the increase of HPMC proportion in other formulations as observed in in vitro dissolution. Drug-cyclodextrin complexes in the tablet improved permeation due to its improved dissolution at the site of biointerface of tablet and buccomucosa. Correlations of ex vivo and in vitro data have been established to predict the buccomucosal permeation from the swelling index or drug release alone.

  14. Thermodynamic study on salt effects on complex formation of α-, β- and γ-cyclodextrins with p-aminobenzoic acid

    International Nuclear Information System (INIS)

    Chibunova, E.S.; Kumeev, R.S.; Terekhova, I.V.

    2015-01-01

    Highlights: • Thermodynamic study on salt effects in CD/pABA complex formation was performed. • Effects of KCl, KH 2 PO 4 and K 2 SO 4 are insignificant and nonspecific. • Specific influence of KBr is caused by the ability of Br − to penetrate into CD cavity. • Coexistence of two complexation equilibria is accompanied by solvent reorganization. - Abstract: The aim of this work was to gain a deeper understanding of salt effects in the inclusion complex formation of cyclodextrins. For this purpose, thermodynamic study of complex formation of α-, β- and γ-cyclodextrins with p-aminobenzoic acid was carried out in water and solutions of KCl, KBr, KH 2 PO 4 and K 2 SO 4 (0.2 mol/kg). Stability constants were calculated from the binding isotherms obtained on the basis of 1 H NMR measurements. Enthalpy and entropy of complex formation were estimated from the van’t Hoff plots. It was found that effects of KCl, KH 2 PO 4 and K 2 SO 4 are insignificant, while the influence of KBr on complex formation of cyclodextrins with p-aminobenzoic acid is more pronounced and results in a decrease of the stability constants. Specific action of Br − is caused by the ability of these anions to penetrate into macrocyclic cavity. Coexistence of two complexation equilibria in KBr solution is accompanied by significant solvent reorganization originated from more intensive dehydration of the interacting species. This results in an increase of the enthalpy and entropy of complex formation. Manifestation of Br − effect was found to be the same in the binding of p-aminobenzoic acid with α-, β- and γ-cyclodextrins.

  15. Molecule-binding dependent assembly of split aptamer and γ-cyclodextrin: A sensitive excimer signaling approach for aptamer biosensors

    International Nuclear Information System (INIS)

    Jin, Fen; Lian, Yan; Li, Jishan; Zheng, Jing; Hu, Yaping; Liu, Jinhua; Huang, Jin; Yang, Ronghua

    2013-01-01

    Graphical abstract: Adenosine-binding aptamer was splitted into two fragments P2 and P3 which labeled pyrene molecules, mainly produce monomer signal. γ-CD cavity brings P2 and P3 in close proximity, allowing for weak excimer emission. In the presence of target, P2 and P3 are expected to bind ATP and form an aptamer/target complex, leads to large increase of the pyrene excimer fluorescence. -- Highlights: •We assembled split aptamer and γ-cyclodextrin fluorescence biosensors for ATP detection. •The biosensor increased quantum yield and emission lifetime of the excimer. •Time-resolved fluorescence is effective for ATP assay in complicated environment. -- Abstract: A highly sensitive and selective fluorescence aptamer biosensors for the determination of adenosine triphosphate (ATP) was developed. Binding of a target with splitting aptamers labeled with pyrene molecules form stable pyrene dimer in the γ-cyclodextrin (γ-CD) cavity, yielding a strong excimer emission. We have found that inclusion of pyrene dimer in γ-cyclodextrin cavity not only exhibits additive increases in quantum yield and emission lifetime of the excimer, but also facilitates target-induced fusion of the splitting aptamers to form the aptamer/target complex. As proof-of-principle, the approach was applied to fluorescence detection of adenosine triphosphate. With an anti-ATP aptamer, the approach exhibits excimer fluorescence response toward ATP with a maximum signal-to-background ratio of 32.1 and remarkably low detection limit of 80 nM ATP in buffer solution. Moreover, due to the additive fluorescence lifetime of excimer induced by γ-cyclodextrin, time-resolved measurements could be conveniently used to detect as low as 0.5 μM ATP in blood serum quantitatively

  16. Comparison of Aqueous and 1-Octanol Solubility as well as Liquid?Liquid Distribution of Acyclovir Derivatives and Their Complexes with Hydroxypropyl-?-Cyclodextrin

    OpenAIRE

    Ko?bia?, Ma?gorzata; Gierycz, Pawe?

    2013-01-01

    The aim of the presented work is the comparison of aqueous and 1-octanol solubilities of different acyclovir derivatives and their hydroxypropyl-?-cyclodextrin inclusion complexes. The solubility measurements were carried out at different temperatures over the range 25?45??C using water, 1-octanol, water saturated with 1-octanol, 1-octanol saturated with water, buffered aqueous solutions (pH?=?5.5 and 7.0) and buffered aqueous solutions containing cyclodextrin as solvents. The aqueous solubil...

  17. Carboxymethyl-β-cyclodextrin Modified Magnetic Nanoparticles for Effective Removal of Arsenic from Drinking Water: Synthesis and Adsorption Studies

    Directory of Open Access Journals (Sweden)

    Sedigheh Zeinali

    2016-11-01

    Full Text Available The β-cyclodextrin coated magnetic nanoparticles were prepared by the surface modification of Fe3O4 magnetic nanoparticles using carboxymethyl-β-cyclodextrin. Prepared nanoparticles were characterized by X-ray diffraction analysis, transmission electron microscope, Fourier transform infrared spectroscopy, dynamic light scattering and vibrating sample magnetometer. The β-cyclodextrin modified Fe3O4 nanoparticles have a narrow size distribution with mean diameter about 10 nm. They exhibit superparamagnetic properties at room temperature with saturation magnetization of 48 emu/g. Since, the most reported technologies for arsenic removal are more effective in removing As(V rather than As(III, the adsorption ability of these nanoparticles was investigated for removing As (III from aqueous solution. The adsorption behavior of this material can be influenced by various factors such as contact time, pH, adsorbent dosage and initial concentration of As(III, which their effects were studied. Equilibrium data were fitted by Langmuir isotherm and the maximum removal percentage was obtained about 85% at optimum conditions. Using these modified Fe3O4 nanoparticles, the arsenic concentrations can be reduced to the allowed limits declared by the World Health Organization.

  18. Interaction of hydroxypropyl-beta-cyclodextrin with peptides, studied by reversed-phase thin-layer chromatography

    Czech Academy of Sciences Publication Activity Database

    Gere-Pászti, E.; Cserháti, T.; Forgács, E.; Deyl, Zdeněk; Mikšík, Ivan; Eckhardt, Adam; Illés, Z.

    2005-01-01

    Roč. 28, č. 16 (2005), s. 2619-2632 ISSN 1082-6076 Grant - others:CZ-HU(CZ) Cooperation program Institutional research plan: CEZ:AV0Z50110509 Keywords : cyclodextrin * peptides * nonlinear map Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.814, year: 2005

  19. Redox-Active Carbohydrate-Coated Nanoparticles: Self-Assembly of a Cyclodextrin-Polystyrene Glycopolymer with Tetrazine-Naphthalimide.

    Science.gov (United States)

    Gross, Andrew J; Haddad, Raoudha; Travelet, Christophe; Reynaud, Eric; Audebert, Pierre; Borsali, Redouane; Cosnier, Serge

    2016-11-15

    The controlled self-assembly of precise and well-defined photochemically and electrochemically active carbohydrate-coated nanoparticles offers the exciting prospect of biocompatible catalysts for energy storage/conversion and biolabeling applications. Here an aqueous nanoparticle system has been developed with a versatile outer layer for host-guest molecule encapsulation via β-cyclodextrin inclusion complexes. A β-cyclodextrin-modified polystyrene polymer was first obtained by copper nanopowder click chemistry. The glycopolymer enables self-assembly and controlled encapsulation of tetrazine-naphthalimide, as a model redox-active agent, into nanoparticles via nanoprecipitation. Cyclodextrin host-guest interactions permit encapsulation and internanoparticle cross-linking for the formation of fluorescent compound and clustered self-assemblies with chemically reversible electroactivity in aqueous solution. Light scattering experiments revealed stable particles with hydrodynamic diameters of 138 and 654 nm for nanoparticles prepared with tetrazine, of which 95% of the nanoparticles represent the smaller objects by number. Dynamic light scattering revealed differences as a function of preparation method in terms of size, 3-month stability, polydispersity, radius of gyration, and shape factor. Individual self-assemblies were visualized by atomic force microscopy and fluorescence microscopy and monitored in real-time by nanoparticle tracking analysis. UV-vis and fluorescence spectra provided insight into the optical properties and critical evidence for host-guest encapsulation as evidenced by solvachromatism and enhanced tetrazine uptake. Cyclic voltammetry was used to investigate the electrochemical properties and provided further support for encapsulation and an estimate of the tetrazine loading capacity in tandem with light scattering data.

  20. Comparative effects of several cyclodextrins on the extraction of PAHs from an aged contaminated soil

    International Nuclear Information System (INIS)

    Sánchez-Trujillo, M.A.; Morillo, E.; Villaverde, J.; Lacorte, S.

    2013-01-01

    The objective of the present study was to characterise the polycyclic aromatic hydrocarbons (PAHs) content of an aged contaminated soil and to propose remediation techniques using cyclodextrins (CDs). Four CDs solutions were tested as soil decontamination tool and proved more efficient in extracting PAHs than when an aqueous solution was used; especially two chemically modified CDs resulted in higher extraction percentages than natural β-CD. The highest extraction percentages were obtained for 3-ring PAHs, because of the appropriate size and shape of these compounds relative to those of the hydrophobic cavities of the CDs studied. A detailed mechanistic interpretation of the chemical modification of CDs on the extraction of the different PAHs has been performed, and connected with the role that the different hydrophobicities of the PAHs play in the extraction behaviour observed for the 16 PAHs, limiting their accessibility and the remaining risk of those PAHs not extractable by CDs. -- Highlights: ► Four cyclodextrins (CDs) solutions were tested as soil decontamination tool for PAHs. ► Extractions with CDs were higher than with electrolyte, especially with synthetic CDs. ► Extraction capacity depends on the adequate size of PAHs and CDs hydrophobic cavity. ► 2–3 ring PAHs, the more abundant in the soil, were extracted in higher percentages. ► CDs extract preferably the less hydrophobic and more potentially toxic PAHs. -- Cyclodextrin solutions are useful and interesting tools for the decontamination of soils polluted by PAHs

  1. Glycemic Response to Corn Starch Modified with Cyclodextrin Glycosyltransferase and its Relationship to Physical Properties.

    Science.gov (United States)

    Dura, A; Yokoyama, W; Rosell, C M

    2016-09-01

    Corn starch was modified with cyclodextrin glycosyltransferase (CGTase) below the gelatinization temperature. The porous granules with or without CGTase hydrolysis products may be used as an alternative to modified corn starches in foods applications. The amount and type of hydrolysis products were determined, containing mainly β-cyclodextrin (CD), which will influence pasting behavior and glycemic response in mice. Irregular surface and small holes were observed by microscopic analysis and differences in pasting properties were observed in the presence of hydrolysis products. Postprandial blood glucose in mice fed gelatinized enzymatically modified starch peaked earlier than their ungelatinized counterparts. However, in ungelatinized enzymatically modified starches, the presence of β- CD may inhibit the orientation of amylases slowing hydrolysis, which may help to maintain lower blood glucose levels. Significant correlations were found between glycemic curves and viscosity pattern of starches.

  2. Nano- and microsized cubic gel particles from cyclodextrin metal-organic frameworks.

    Science.gov (United States)

    Furukawa, Yuki; Ishiwata, Takumi; Sugikawa, Kouta; Kokado, Kenta; Sada, Kazuki

    2012-10-15

    Sweet cube o' mine: Bottom-up control of gel particles has been regarded as a great challenge. By employing internal cross-linking of cyclodextrin metal-organic frameworks, cubic sugar gels were formed with sharp edges that reflect the shape of the crystals. This enabled the fabrication of shape- and size-controlled polymer gels from porous crystals (see picture). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Properties of cyclodextrins. II. Preparation of a stable β-cyclodextrin hydrate and determination of its water content and enthalpy of solution in water from 15 to 30.deg

    NARCIS (Netherlands)

    Wiedenhof, N.; Lammers, J.N.J.J.

    1968-01-01

    The solubility of ß-cyclodextrin (ß-CD) in water has been measured by a refractive-index method at 15–30°. Evidence was obtained that the same, solid ß-CD hydrate phase is present in this temperature range. The formula of the hydrate was shown to be C42H70O35(12.0 ± 0.5)H20. A method for preparation

  4. Enrichment and sensitive detection of polyphenolic compounds via β-cyclodextrin functionalized fluorescent gold nanorods

    International Nuclear Information System (INIS)

    Luo, Jinmei; Zhang, Jiahui; Lin, Jianxing; Wang, Jinhui; Yang, Peihui

    2015-01-01

    We report on a simple and rapid method for the enrichment of polyphenolic compounds (pPhCs) by means of gold nanorods whose surface was functionalized with a monolayer of β-cyclodextrin (β-CD-AuNRs) via thiol chemistry. Enrichment is based on the formation of inclusion complexes between pPhCs and β-cyclodextrin through hydrophobic interactions and hydrogen bonding. Fourier transform infrared spectroscopy, mass spectrometry, and transmission electron microscopy were applied to confirm the inclusion of the pPhCs. Moreover, binding leads to a quenching of the red fluorescence of the AuNRs. This effect can be applied to quantify the polyphenols mangiferin, chrysin, and daphnetin with detection limits at 5 nM, 15 nM, and 20 nM concentrations, respectively. Water samples were spiked with pPhCs, and their extraction by using β-CD-AuNRs gave recoveries ranging from 97.6 to 110.2 %. (author)

  5. Chemical Sensors Based on Cyclodextrin Derivatives.

    Science.gov (United States)

    Ogoshi, Tomoki; Harada, Akira

    2008-08-25

    This review focuses on chemical sensors based on cyclodextrin (CD) derivatives. This has been a field of classical interest, and is now of current interest for numerous scientists. First, typical chemical sensors using chromophore appended CDs are mentioned. Various "turn-off" and "turn-on" fluorescent chemical sensors, in which fluorescence intensity was decreased or increased by complexation with guest molecules, respectively, were synthesized. Dye modified CDs and photoactive metal ion-ligand complex appended CDs, metallocyclodextrins, were also applied for chemical sensors. Furthermore, recent novel approaches to chemical sensing systems using supramolecular structures such as CD dimers, trimers and cooperative binding systems of CDs with the other macrocycle [2]rotaxane and supramolecular polymers consisting of CD units are mentioned. New chemical sensors using hybrids of CDs with p-conjugated polymers, peptides, DNA, nanocarbons and nanoparticles are also described in this review.

  6. Characterization of the inclusion complex ropivacaine: β-cyclodextrin

    International Nuclear Information System (INIS)

    Fraceto, Leonardo Fernandes; Moraes, Carolina Morales; Araujo, Daniele Ribeiro de; Zanella, Luciana; Paula, Eneida de; Pertinhez, Thelma de Aguiar

    2007-01-01

    Ropivacaine (RVC) is a widely used local anesthetic. The complexation of RVC with β-cyclodextrin (β-CD) is of great interest for the development of more efficient local anesthetic formulations. The present work focuses on the characterization of the RVC:β-CD complex by nuclear magnetic resonance (NMR). The stoichiometry of the complex is 1:2 RVC:β-CD. DOSY-NMR shows that the association constant is 55.5 M -1 . Longitudinal relaxation time results show that RVC changes its mobility in the presence of β-CD. This study is focused on the physicochemical characterization of inclusion complexes that are potentials options for pain treatment. (author)

  7. Hartree-Fock and density functional theory study of alpha-cyclodextrin conformers.

    Science.gov (United States)

    Jiménez, Verónica; Alderete, Joel B

    2008-01-31

    Herein, we report the geometry optimization of four conformers of alpha-cyclodextrin (alpha-CD) by means of PM3, HF/STO-3G, HF/3-21G, HF/6-31G(d), B3LYP/6-31G(d), and X3LYP/6-31G(d) calculations. The analysis of several geometrical parameters indicates that all conformers possess bond lengths, angles, and dihedrals that agree fairly well with the crystalline structure of alpha-CD. However, only three of them (1-3) resemble the polar character of CDs and show intramolecular hydrogen-bonding patterns that agree with experimental NMR data. Among them, conformer 3 appears to be the most stable species both in the gas phase and in solution; therefore, it is expected to be the most suitable representative structure for alpha-CD conformation. The purpose of selecting such a species is to identify an appropriate structure to be employed as a starting point for reliable computational studies on complexation phenomena. Our results indicate that the choice of a particular alpha-CD conformer should affect the results of ab initio computational studies on the inclusion complexation with this cyclodextrin since both the direction and the magnitude of the dipole moment depend strongly on the conformation of alpha-CD.

  8. Electrospinning of functional poly(methyl methacrylate) nanofibers containing cyclodextrin-menthol inclusion complexes

    Energy Technology Data Exchange (ETDEWEB)

    Uyar, Tamer; Besenbacher, Flemming [Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000, Aarhus C (Denmark); Nur, Yusuf; Hacaloglu, Jale [Department of Chemistry, Middle East Technical University, Ankara, 06530 (Turkey)], E-mail: tamer@inano.dk, E-mail: tamer@unam.bilkent.edu.tr

    2009-03-25

    Electrospinning of nanofibers with cyclodextrin inclusion complexes (CD-ICs) is particularly attractive since distinct properties can be obtained by combining the nanofibers with specific functions of the CD-ICs. Here we report on the electrospinning of poly(methyl methacrylate) (PMMA) nanofibers containing cyclodextrin-menthol inclusion complexes (CD-menthol-ICs). These CD-menthol-IC functionalized nanofibers were developed with the purpose of producing functional nanofibers that contain fragrances/flavors with high temperature stability, and menthol was used as a model fragrance/flavor material. The PMMA nanofibers were electrospun with CD-menthol-ICs using three type of CD: {alpha}-CD, {beta}-CD, and {gamma}-CD. Direct pyrolysis mass spectrometry (DP-MS) studies showed that the thermal evaporation of menthol occurred over a very high and a broad temperature range (100-355 deg. C) for PMMA/CDmenthol-IC nanowebs, demonstrating the complexation of menthol with the CD cavity and its high temperature stability. Furthermore, as the size of CD cavity increased in the order {alpha}-CD<{beta}-CD<{gamma}-CD, the thermal evolution of menthol shifted to higher temperatures, suggesting that the strength of interaction between menthol and the CD cavity is in the order {gamma}-CD>{beta}-CD>{alpha}-CD.

  9. Construction of hydroxypropyl-{beta}-cyclodextrin copolymer nanoparticles and targeting delivery of paclitaxel

    Energy Technology Data Exchange (ETDEWEB)

    Miao Qinghua; Li Suping; Han Siyuan [National Center for Nanoscience and Technology of China, CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety (China); Wang Zhi, E-mail: wangzhi@jlu.edu.cn [Jilin University, Key Laboratory for Molecular Enzymology and Engineering, Ministry of Education (China); Wu Yan, E-mail: wuy@nanoctr.cn; Nie Guangjun, E-mail: niegj@nanoctr.cn [National Center for Nanoscience and Technology of China, CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety (China)

    2012-08-15

    A novel amphiphilic copolymer with p-maleimidophenyl isocyanate-hydroxypropyl-{beta}-cyclodextrin-polylactide-1, 2-dipalmitoyl-sn-glycero-3-phosphoethanolamine to generate copolymer nanoparticles (NPs) has been designed. In order to develop an active targeting system, integrin {alpha}{sub v}{beta}{sub 3}-specific targeting peptide cyclo(Arg-Gly-Asp-D-Phe-Cys), cRGD, was conjugated to the surface of NPs (NPs-RGD). These NPs were used to encapsulate anti-tumor drug, paclitaxel. The resulting NPs exhibited high drug-loading capacity and controlled drug release in vitro at acidic pH. In vitro cytotoxicity assay demonstrates that paclitaxel-loaded NPs-RGD significantly inhibited B16 tumor cell (high {alpha}{sub v}{beta}{sub 3}) proliferation relative to free paclitaxel and paclitaxel-loaded NPs at high concentrations. Paclitaxel-loaded NPs-RGD localized mainly in lysosomes in B16 cells as revealed by confocal microscopy. These results suggest a novel strategy for fabrication-functionalizing hydroxypropyl-{beta}-cyclodextrin copolymer nanoparticles for targeting delivery of paclitaxel to integrin {alpha}{sub v}{beta}{sub 3}-rich tumor cells. These nanocarriers can be readily extended to couple other bioactive molecules for active targeting and delivery of various chemotherapeutic drugs.

  10. Magnetic porous corn starch for the affinity purifi cation of cyclodextrin glucanotransferase produced by Bacillus circulans

    Czech Academy of Sciences Publication Activity Database

    Šafaříková, Miroslava; Horská, Kateřina; Maděrová, Zdeňka; Tonkova, A.; Ivanova-Pashkoulova, V.; Šafařík, Ivo

    2012-01-01

    Roč. 30, č. 1 (2012), s. 96-101 ISSN 1024-2422 Institutional support: RVO:67179843 Keywords : Bacillus circulans * cyclodextrin glucanotransferase * magnetic starch * magnetic separation Subject RIV: EH - Ecology, Behaviour Impact factor: 0.895, year: 2012

  11. Electronic structure and driving forces in β-cyclodextrin: Diclofenac inclusion complexes

    International Nuclear Information System (INIS)

    Bogdan, Diana; Morari, C.

    2007-01-01

    We investigate the geometry and electronic structure for complexes of β-cyclodextrin with diclofenac using DFT calculations. The effect of solvent is explicitly taken into account. This investigation allows us to draw meaningful conclusions upon the stability of the complex and the nature of the driving forces leading to the complexation process. In particular we emphasize the role of the water, by pointing out the changes in the solvent's electronic structure for different docking geometries

  12. Sorption of Aromatic Compounds with Copolymer Sorbent Materials Containing β-Cyclodextrin

    OpenAIRE

    Wilson, Lee D.; Mohamed, Mohamed H.; Berhaut, Christopher L.

    2011-01-01

    Urethane copolymer sorbent materials that incorporate β-cyclodextrin (CD) have been prepared and their sorption properties with chlorinated aromatic compounds (i.e., pentachlorophenol, 2,4-dichlorophenol and 2,4-dichlorophenoxy acetic acid) have been evaluated. The sorption properties of granular activated carbon (GAC) were similarly compared in aqueous solution at variable pH conditions. The sorbents displayed variable BET surface areas as follows: MDI-X copolymers (< 101 m2/g), CDI-X cop...

  13. Magnetite nanoparticles coated with β-cyclodextrin functionalized-ionic liquid: Synthesis and its preliminary investigation as a new sensing material

    International Nuclear Information System (INIS)

    Sinniah, Subathra; Mohamad, Sharifah; Manan, Ninie S.A.

    2015-01-01

    Highlights: • A novel of β-cyclodextrin functionalized-ionic liquid coated with magnetite nanoparticles is prepared via co-precipitation method. • The architecture of the material is successfully characterized and confirmed that β-cyclodextrin-functionalized-ionic liquid, has been effectively coated onto surface of Fe 3 O 4 magnetite nanoparticles. • Vibration Sample Magnetometer analysis confirmed that the Fe 3 O 4 -β-CD-IL able to attain an excellent magnetic properties. • Preliminary electrochemical study shows that Fe 3 O 4 -β-CD-IL able to recognize Biphenol A. - Abstract: In this study, a novel surface of modified magnetite nanoparticles Fe 3 O 4 was coated with β-cyclodextrin-funclionalized ionic liquid (Fe 3 O 4 -β-CD-IL) via the co-precipitation method in alkaline salt medium. β-Cyclodextrin-functionalized-ionic liquid has been effectively coated onto the surface of Fe 3 O 4 magnetite nanoparticles. The instruments used to investigate the architecture are: Fourier Transform Infrared Spectroscopy, X-ray Powder Diffraction, Electron Microscope-Energy Dispersive X-Ray Spectrometry, Transmission Electron Microscope, Field Emission Scanning Electron Microscope, Vibrating Sample Magnetometer and Brunauer–Emmett–Teller isotherm. A Vibration Sample Magnetometer analysis verified that the Fe 3 O 4 -β-CD-IL attained excellent magnetic properties. The analysis of High Resolution Transmission Electron Microscope shows that the Fe 3 O 4 -β-CD-IL produced monodisperse particles with minimal aggregation. Moreover, electrochemical studies have revealed that this new material showed outstanding ability to recognize Bisphenol A with lower electrochemical potential at 0.5 V than other comparative materials, as well as a higher detection current. Thus, this material has promising potential as a new electrode material in sensor applications.

  14. Cyclodextrin-Enhanced In Situ Removal of Organic Contaminants from Groundwater at Department of Defense Sites

    Science.gov (United States)

    2004-05-01

    Advantage Nontoxic to humans and resident microbial populations Cyclodextrins are widely used in pharmaceuticals, food processing, and cosmetics ...dechlorination of tetrachloroethene by the Fenton reaction. Environ. Sci. Technol., 17 (9): 1689-1694. 25. Yin, Y., Allen, H.E., 1999: In situ chemical

  15. The effects of cyclodextrins on drug release from fatty suppository bases : II. In vivo observations

    NARCIS (Netherlands)

    Frijlink, H.W.; Eissens, Anko; Schoonen, Adelbert; Lerk, C.F.

    The effects of cyclodextrin complexation on the absorption of drugs from fatty suppositories was evaluated in human volunteers. Three model drugs: diazepam, ibuprofen and prednisolone were used. When diazepam was complexed with γ-cyclcodextrin the drug release from the fatty suppositories was

  16. Designed biocompatible nano-inhibitor based on poly(β-cyclodextrin-ester) for reduction of the DEHP migration from plasticized PVC.

    Science.gov (United States)

    Raeisi, Ahmad; Faghihi, Khalil; Shabanian, Meisam

    2017-10-15

    The easy migration of di(2-ethylhexyl) phthalate (DEHP) from the plasticized PVC (P-PVC) poses a serious threat to human health and the ecosystems. Thus, its control migration from the P-PVC products is very important. In this work, a poly(β-cyclodextrin-ester) network (β-CDP) was synthesized via reaction of β-cyclodextrin with 3,3',4,4'-benzophenone tetracarboxylic dianhydride. As a potential inhibitor for reduction of the DEHP migration, the β-CDP was grafted to Fe 3 O 4 nanoparticles. Poly(β-cyclodextrin-ester) functionalized Fe 3 O 4 nanoparticles (MNP-CDP) has been used in PVC/DEHP system as a reactive nano-inhibitor to reduce DEHP migration. Thermal stability and mechanical properties of obtained films were investigated. DEHP migration tests of the P-PVC films were also carried out by using Gas chromatography. It was found that by incorporating the small amounts of nano-inhibitor in PVC/DEHP system, the migration of DEHP effectively reduced from the P-PVC samples about 65% without any serious changes in mechanical and thermal properties of the P-PVC films. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Chiral separation of dansyl amino acids in capillary electrophoresis using mono-(3-methyl-imidazolium)-beta-cyclodextrin chloride as selector.

    Science.gov (United States)

    Tang, Weihua; Ong, Teng Teng; Ng, Siu-Choon

    2007-06-01

    Enantioseparations of fourteen dansyl amino acids were achieved by using a positively-charged single-isomer beta-cyclodextrin, mono-(3-methyl-imidazolium)-beta-cyclodextrin chloride, as a chiral selector. Separation parameters such as buffer pH, selector concentration, separation temperature, and organic modifier were investigated for the enantioseparation in order to achieve the maximum possible resolution. Chiral separation of dansyl amino acids was found to be highly dependent on pH since the degree of protonation of these amino acids can alter the strength of electrostatic interaction and/or inclusion complexation between each enantiomer and chiral selector. In general, the chiral resolution of dansyl amino acids was enhanced at higher pH, which indicates that the carboxylate group on the analytes may interact with the imidazolium group of cationic cyclodextrin. For most analytes, a distinct maximum in enantioresolution was obtained at pH 8.0. Moreover, the chiral separation can be further improved by careful tuning of the separation parameters such as higher selector concentration (e.g. 10 mM), lower temperature, and addition of methanol. Enantioseparation of a standard mixture of these dansyl amino acids was further achieved in a single run within 30 min.

  18. Preparation of a β-Cyclodextrin-Based Open-Tubular Capillary Electrochromatography Column and Application for Enantioseparations of Ten Basic Drugs.

    Directory of Open Access Journals (Sweden)

    Linlin Fang

    Full Text Available An open-tubular capillary electrochromatography column was prepared by chemically immobilized β-cyclodextrin modified gold nanoparticles onto new surface with the prederivatization of (3-mercaptopropyl-trimethoxysilane. The synthesized nanoparticles and the prepared column were characterized by transmission electron microscopy, scanning electron microscopy, infrared spectroscopy and ultraviolet visible spectroscopy. When the column was employed as the chiral stationary phase, no enantioselectivity was observed for ten model basic drugs. So β-cyclodextrin was added to the background electrolyte as chiral additive to expect a possible synergistic effect occurring and resulting in a better separation. Fortunately, significant improvement in enantioselectivity was obtained for ten pairs of drug enantiomers. Then, the effects of β-cyclodextrin concentration and background electrolyte pH on the chiral separation were investigated. With the developed separation mode, all the enantiomers (except for venlafaxine were baseline separated in resolutions of 4.49, 1.68, 1.88, 1.57, 2.52, 2.33, 3.24, 1.63 and 3.90 for zopiclone, chlorphenamine maleate, brompheniramine maleate, dioxopromethazine hydrochloride, carvedilol, homatropine hydrobromide, homatropine methylbromide, venlafaxine, sibutramine hydrochloride and terbutaline sulfate, respectively. Further, the possible separation mechanism involved was discussed.

  19. Formation of poly(ethylene glycol) inclusion complexes in aqueous solutions of mixed cyclodextrins

    Czech Academy of Sciences Publication Activity Database

    Horský, Jiří; Walterová, Zuzana

    2003-01-01

    Roč. 203, - (2003), s. 259-264 ISSN 1022-1360. [International Conference on Polymer-Solvent Complexes and Intercalates /4./. Prague, 22.07.2002-25.07.2002] R&D Projects: GA AV ČR IAA1050101 Institutional research plan: CEZ:AV0Z4050913 Keywords : cyclodextrins * inclusion complexes * phase separation Subject RIV: BO - Biophysics Impact factor: 0.895, year: 2003

  20. Induction of mitophagy-mediated antitumor activity with folate-appended methyl-β-cyclodextrin

    Directory of Open Access Journals (Sweden)

    Kameyama K

    2017-04-01

    Full Text Available Kazuhisa Kameyama,1,* Keiichi Motoyama,1,* Nao Tanaka,1 Yuki Yamashita,1 Taishi Higashi,1 Hidetoshi Arima1,2,* 1Department of Physical Pharmaceutics, Graduate School of Pharmaceutical Sciences, 2Program for Leading Graduate Schools “HIGO (Health Life Science: Interdisciplinary and Glocal Oriented Program,” Kumamoto University, Kumamoto, Japan *These authors contributed equally to this work Abstract: Mitophagy is the specific autophagic elimination system of mitochondria, which regulates cellular survival via the removal of damaged mitochondria. Recently, we revealed that folate-appended methyl-β-cyclodextrin (FA-M-β-CyD provides selective antitumor activity in folate receptor-α (FR-α-expressing cells by the induction of autophagy. In this study, to gain insight into the detailed mechanism of this antitumor activity, we focused on the induction of mitophagy by the treatment of FR-α-expressing tumor cells with FA-M-β-CyD. In contrast to methyl-β-cyclodextrin, FA-M-β-CyD entered KB cells, human epithelial cells from a fatal cervical carcinoma (FR-α (+ through FR-α-mediated endocytosis. The transmembrane potential of isolated mitochondria after treatment with FA-M-β-CyD was significantly elevated. In addition, FA-M-β-CyD lowered adenosine triphosphate (ATP production and promoted reactive oxygen species production in KB cells (FR-α (+. Importantly, FA-M-β-CyD enhanced light chain 3 (LC3 conversion (LC3-I to LC3-II in KB cells (FR-α (+ and induced PTEN-induced putative kinase 1 (PINK1 protein expression, which is involved in the induction of mitophagy. Furthermore, FA-M-β-CyD had potent antitumor activity in BALB/c nu/nu mice xenografted with KB cells (FR-α (+ without any significant side effects. Taken together, these findings demonstrate that the autophagic cell death elicited by FA-M-β-CyD could be associated with mitophagy induced by an impaired mitochondrial function. Keywords: mitophagy, autophagy, folate receptor, methyl-β-cyclodextrin

  1. Characterization of the Sublimation and Vapor Pressure of 2-(2-Nitrovinyl) Furan (G-0) Using Thermogravimetric Analysis: Effects of Complexation with Cyclodextrins.

    Science.gov (United States)

    Ruz, Vivian; González, Mirtha Mayra; Winant, Danny; Rodríguez, Zenaida; Van den Mooter, Guy

    2015-08-19

    In the present work, the sublimation of crystalline solid 2-(2-nitrovinyl) furan (G-0) in the temperature range of 35 to 60 °C (below the melting point of the drug) was studied using thermogravimetric analysis (TGA). The sublimated product was characterized using Fourier-transformed-infrared spectroscopy (FT-IR) and thin layer chromatography (TLC). The sublimation rate at each temperature was obtained using the slope of the linear regression model and followed apparent zero-order kinetics. The sublimation enthalpy from 35 to 60 °C was obtained from the Eyring equation. The Gückel method was used to estimate the sublimation rate and vapor pressure at 25 °C. Physical mixtures, kneaded and freeze-dried complexes were prepared with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and sulfobutyl ether-β-cyclodextrin (SBE-β-CD) and analyzed using isothermal TGA at 50 °C. The complexation contributed to reducing the sublimation process. The best results were achieved using freeze-dried complexes with both cyclodextrins.

  2. Spectroscopic methods for aqueous cyclodextrin inclusion complex binding measurement for 1,4-dioxane, chlorinated co-contaminants, and ozone

    Science.gov (United States)

    Khan, Naima A.; Johnson, Michael D.; Carroll, Kenneth C.

    2018-03-01

    Recalcitrant organic contaminants, such as 1,4-dioxane, typically require advanced oxidation process (AOP) oxidants, such as ozone (O3), for their complete mineralization during water treatment. Unfortunately, the use of AOPs can be limited by these oxidants' relatively high reactivities and short half-lives. These drawbacks can be minimized by partial encapsulation of the oxidants within a cyclodextrin cavity to form inclusion complexes. We determined the inclusion complexes of O3 and three common co-contaminants (trichloroethene, 1,1,1-trichloroethane, and 1,4-dioxane) as guest compounds within hydroxypropyl-β-cyclodextrin. Both direct (ultraviolet or UV) and competitive (fluorescence changes with 6-p-toluidine-2-naphthalenesulfonic acid as the probe) methods were used, which gave comparable results for the inclusion constants of these species. Impacts of changing pH and NaCl concentrations were also assessed. Binding constants increased with pH and with ionic strength, which was attributed to variations in guest compound solubility. The results illustrate the versatility of cyclodextrins for inclusion complexation with various types of compounds, binding measurement methods are applicable to a wide range of applications, and have implications for both extraction of contaminants and delivery of reagents for treatment of contaminants in wastewater or contaminated groundwater.

  3. Role of Electroosmosis in the Permeation of Neutral Molecules: CymA and Cyclodextrin as an Example.

    Science.gov (United States)

    Bhamidimarri, Satya Prathyusha; Prajapati, Jigneshkumar Dahyabhai; van den Berg, Bert; Winterhalter, Mathias; Kleinekathöfer, Ulrich

    2016-02-02

    To quantify the flow of small uncharged molecules into and across nanopores, one often uses ion currents. The respective ion-current fluctuations caused by the presence of the analyte make it possible to draw some conclusions about the direction and magnitude of the analyte flow. However, often this flow appears to be asymmetric with respect to the applied voltage. As a possible reason for this asymmetry, we identified the electroosmotic flow (EOF), which is the water transport associated with ions driven by the external transmembrane voltage. As an example, we quantify the contribution of the EOF through a nanopore by investigating the permeation of α-cyclodextrin through CymA, a cyclodextrin-specific channel from Klebsiella oxytoca. To understand the results from electrophysiology on a molecular level, all-atom molecular dynamics simulations are used to detail the effect of the EOF on substrate entry to and exit from a CymA channel in which the N-terminus has been deleted. The combined experimental and computational results strongly suggest that one needs to account for the significant contribution of the EOF when analyzing the penetration of cyclodextrins through the CymA pore. This example study at the same time points to the more general finding that the EOF needs to be considered in translocation studies of neutral molecules and, at least in many cases, should be able to help in discriminating between translocation and binding events. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  4. Ascorbyl Tetraisopalmitate Inclusion into Υ-Cyclodextrin and Mesoporous SBA-15: Preparation, Characterization and In Vitro Release Study

    Directory of Open Access Journals (Sweden)

    Maria Bastianini

    2017-07-01

    Full Text Available Ascorbic acid or vitamin C is a strong antioxidant widely used in cosmetic and food fields. This vitamin is very unstable and rapidly undergoes degradation. In order to solve this problem and to obtain a stable ascorbic acid, Nikkol Group has developed ascorbyltetraisopalmitate (VC-IP. This raw material is an oil phase, already well-known and employed in the cosmetic market. The objective of this study is to obtain VC-IP in micro-powder form, in order to produce a new raw material that is easily dispersible in oil and water phases and useful for make-up and color cosmetic applications. Various types of drug carriers were studied and considered in order to support VC-IP and obtain the conversion in powder. Υ-cyclodextrin and mesoporous silica SBA-15 were chosen as the best candidates. A white powder of supported VC-IP was obtained with each carrier (VC-IP@cyclodextrin, VC-IP@SBA-15. The systems underwent physicochemical characterization and in vitro release tests were carried out. Based on the conducted study, it can be concluded that by supporting VC-IP on Υ-cyclodextrin and SBA-15, it is feasible to obtain a new raw material in powder form. The two carriers possess different release profiles, adding the possibility to finely tune the release of the active component in smart formulations.

  5. Intramolecular Oxidative O-Demethylation of an Oxoferryl Porphyrin Complexed with a Per-O-methylated β-Cyclodextrin Dimer.

    Science.gov (United States)

    Kitagishi, Hiroaki; Kurosawa, Shun; Kano, Koji

    2016-11-22

    The intramolecular oxidation of ROCH 3 to ROCH 2 OH, where the latter compound spontaneously decomposed to ROH and HCHO, was observed during the reaction of the supramolecular complex (met-hemoCD3) with cumene hydroperoxide in aqueous solution. Met-hemoCD3 is composed of meso-tetrakis(4-sulfonatophenyl)porphinatoiron(III) (Fe III TPPS) and a per-O-methylated β-cyclodextrin dimer having an -OCH 2 PyCH 2 O- linker (Py=pyridine-3,5-diyl). The O=Fe IV TPPS complex was formed by the reaction of met-hemoCD3 with cumene hydroperoxide, and isolated by gel-filtration chromatography. Although the isolated O=Fe IV TPPS complex in the cyclodextrin cage was stable in aqueous solution at 25 °C, it was gradually converted to Fe II TPPS (t 1/2 =7.6 h). This conversion was accompanied by oxidative O-demethylation of an OCH 3 group in the cyclodextrin dimer. The results indicated that hydrogen abstraction by O=Fe IV TPPS from ROCH 3 yields HO-Fe III TPPS and ROCH 2 . . This was followed by radical coupling to afford Fe II TPPS and ROCH 2 OH. The hemiacetal (ROCH 2 OH) immediately decomposed to ROH and HCHO. This study revealed the ability of oxoferryl porphyrin to induce two-electron oxidation. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Permanent fixation of ss-cyclodextrin on cotton surfaceuAn assessment between innovative and established approaches

    NARCIS (Netherlands)

    Agrawal, Pramod; Warmoeskerken, Marinus

    2012-01-01

    Attachment of β-cyclodextrin (β-CD) molecules on cotton textile provides hosting cavities that can include a large variety of guest molecules for specific functionality. Five different new and existing techniques were evaluated for connecting β-CD and its derivatives to cotton surface. A comparison

  7. Chemical encapsulation of rocuronium by synthetic cyclodextrin derivatives: reversal of neuromuscular block in anaesthetized Rhesus monkeys.

    NARCIS (Netherlands)

    Boer, H.D. de; Egmond, J. van; Pol, F. van de; Bom, A.; Booij, L.H.D.J.

    2006-01-01

    BACKGROUND: At present, reversal of neuromuscular block induced by steroidal neuromuscular blocking agents (NMBAs) is achieved by administration of cholinesterase inhibitors. Chemical encapsulation of steroidal NMBAs, such as rocuronium, by a cyclodextrin is a new concept in neuromuscular block

  8. Electronic structure and driving forces in {beta}-cyclodextrin: Diclofenac inclusion complexes

    Energy Technology Data Exchange (ETDEWEB)

    Bogdan, Diana [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath street 71-103, 400293 Cluj-Napoca (Romania); Morari, C. [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath street 71-103, 400293 Cluj-Napoca (Romania)]. E-mail: cristim@s3.itim-cj.ro

    2007-07-02

    We investigate the geometry and electronic structure for complexes of {beta}-cyclodextrin with diclofenac using DFT calculations. The effect of solvent is explicitly taken into account. This investigation allows us to draw meaningful conclusions upon the stability of the complex and the nature of the driving forces leading to the complexation process. In particular we emphasize the role of the water, by pointing out the changes in the solvent's electronic structure for different docking geometries.

  9. Enhanced mineralization of diuron using a cyclodextrin-based bioremediation technology.

    Science.gov (United States)

    Villaverde, Jaime; Posada-Baquero, Rosa; Rubio-Bellido, Marina; Laiz, Leonila; Saiz-Jimenez, Cesareo; Sanchez-Trujillo, María A; Morillo, Esmeralda

    2012-10-10

    The phenylurea herbicide diuron [N-(3,4-dichlorophenyl)-N,N-dimethylurea] is widely used in a broad range of herbicide formulations and, consequently, it is frequently detected as a major soil and water contaminant in areas where there is extensive use. Diuron has the unfortunate combination of being strongly adsorbed by soil organic matter particles and, hence, slowly degraded in the environment due to its reduced bioavailability. N-Phenylurea herbicides seem to be biodegraded in soil, but it must be kept in mind that this biotic or abiotic degradation could lead to accumulation of very toxic derived compounds, such as 3,4-dichloroaniline. Research was conducted to find procedures that might result in an increase in the bioavailability of diuron in contaminated soils, through solubility enhancement. For this purpose a double system composed of hydroxypropyl-β-cyclodextrin (HPBCD), which is capable of forming inclusion complexes in solution, and a two-member bacterial consortium formed by the diuron-degrading Arthrobacter sulfonivorans (Arthrobacter sp. N2) and the linuron-degrading Variovorax soli (Variovorax sp. SRS16) was used. This consortium can achieve a complete biodegradation of diuron to CO2 with regard to that observed in the absence of the CD solution, where only a 45% biodegradation was observed. The cyclodextrin-based bioremediation technology here described shows for the first time an almost complete mineralization of diuron in a soil system, in contrast to previous incomplete mineralization based on single or consortium bacterial degradation.

  10. Monitoring cyclodextrin-polyviologen pseudopolyrotaxanes with the Bradford assay.

    Science.gov (United States)

    Belitsky, Jason M; Nelson, Alshakim; Stoddart, J Fraser

    2006-01-21

    Self-assembled multivalent pseudopolyrotaxanes, composed of lactoside-bearing cyclodextrin (CD) rings threaded on linear polyviologen polymers, have been introduced recently as flexible and dynamic neoglycoconjugates. In the course of this research, it was found that polyviologens are responsive to the Bradford assay, which is traditionally highly selective for proteins. The response of the pseudopolyrotaxanes to the Bradford assay was dependant on, and thus indicative of, the degree of threading of the CD rings onto the polyelectrolyte. The assay was then used to report on the threading and dethreading of native and lactoside-bearing alpha-CD rings onto and off of polyviologen chains, a phenomenon which demonstrates the utility of biochemical assays to address problems unique to supramolecular chemistry.

  11. Cyclodextrins in delivery systems: Applications

    Directory of Open Access Journals (Sweden)

    Gaurav Tiwari

    2010-01-01

    Full Text Available Cyclodextrins (CDs are a family of cyclic oligosaccharides with a hydrophilic outer surface and a lipophilic central cavity. CD molecules are relatively large with a number of hydrogen donors and acceptors and, thus in general, they do not permeate lipophilic membranes. In the pharmaceutical industry, CDs have mainly been used as complexing agents to increase aqueous solubility of poorly soluble drugs and to increase their bioavailability and stability. CDs are used in pharmaceutical applications for numerous purposes, including improving the bioavailability of drugs. Current CD-based therapeutics is described and possible future applications are discussed. CD-containing polymers are reviewed and their use in drug delivery is presented. Of specific interest is the use of CD-containing polymers to provide unique capabilities for the delivery of nucleic acids. Studies in both humans and animals have shown that CDs can be used to improve drug delivery from almost any type of drug formulation. Currently, there are approximately 30 different pharmaceutical products worldwide containing drug/CD complexes in the market.

  12. Poly(ethylene glycol) and cyclodextrin-grafted chitosan: from methodologies to preparation and potential biotechnological applications

    Science.gov (United States)

    Campos, Estefânia V. R.; Oliveira, Jhones L.; Fraceto, Leonardo F.

    2017-11-01

    Chitosan, a polyaminosaccharide obtained by alkaline deacetylation of chitin, possesses useful properties including biodegradability, biocompatibility, low toxicity, and good miscibility with other polymers. It is extensively used in many applications in biology, medicine, agriculture, environmental protection, and the food and pharmaceutical industries. The amino and hydroxyl groups present in the chitosan backbone provide positions for modifications that are influenced by factors such as the molecular weight, viscosity, and type of chitosan, as well as the reaction conditions. The modification of chitosan by chemical methods is of interest because the basic chitosan skeleton is not modified and the process results in new or improved properties of the material. Among the chitosan derivatives, cyclodextrin-grafted chitosan and poly(ethylene glycol)-grafted chitosan are excellent candidates for a range of biomedical, environmental decontamination, and industrial purposes. This work discusses modifications including chitosan with attached cyclodextrin and poly(ethylene glycol), and the main applications of these chitosan derivatives in the biomedical field.

  13. Magnetite nanoparticles coated with β-cyclodextrin functionalized-ionic liquid: Synthesis and its preliminary investigation as a new sensing material

    Energy Technology Data Exchange (ETDEWEB)

    Sinniah, Subathra; Mohamad, Sharifah; Manan, Ninie S.A., E-mail: niniemanan@um.edu.my

    2015-12-01

    Highlights: • A novel of β-cyclodextrin functionalized-ionic liquid coated with magnetite nanoparticles is prepared via co-precipitation method. • The architecture of the material is successfully characterized and confirmed that β-cyclodextrin-functionalized-ionic liquid, has been effectively coated onto surface of Fe{sub 3}O{sub 4} magnetite nanoparticles. • Vibration Sample Magnetometer analysis confirmed that the Fe{sub 3}O{sub 4}-β-CD-IL able to attain an excellent magnetic properties. • Preliminary electrochemical study shows that Fe{sub 3}O{sub 4}-β-CD-IL able to recognize Biphenol A. - Abstract: In this study, a novel surface of modified magnetite nanoparticles Fe{sub 3}O{sub 4} was coated with β-cyclodextrin-funclionalized ionic liquid (Fe{sub 3}O{sub 4}-β-CD-IL) via the co-precipitation method in alkaline salt medium. β-Cyclodextrin-functionalized-ionic liquid has been effectively coated onto the surface of Fe{sub 3}O{sub 4} magnetite nanoparticles. The instruments used to investigate the architecture are: Fourier Transform Infrared Spectroscopy, X-ray Powder Diffraction, Electron Microscope-Energy Dispersive X-Ray Spectrometry, Transmission Electron Microscope, Field Emission Scanning Electron Microscope, Vibrating Sample Magnetometer and Brunauer–Emmett–Teller isotherm. A Vibration Sample Magnetometer analysis verified that the Fe{sub 3}O{sub 4}-β-CD-IL attained excellent magnetic properties. The analysis of High Resolution Transmission Electron Microscope shows that the Fe{sub 3}O{sub 4}-β-CD-IL produced monodisperse particles with minimal aggregation. Moreover, electrochemical studies have revealed that this new material showed outstanding ability to recognize Bisphenol A with lower electrochemical potential at 0.5 V than other comparative materials, as well as a higher detection current. Thus, this material has promising potential as a new electrode material in sensor applications.

  14. In vitro photobiochemical characterization of sulfobutylether-β-cyclodextrin formulation of bufexamac.

    Science.gov (United States)

    Seto, Yoshiki; Ochi, Masanori; Igarashi, Naoko; Inoue, Ryo; Oishi, Ami; Toida, Toshihiko; Yamada, Shizuo; Onoue, Satomi

    2011-06-01

    The present study aimed to modulate the photoreactivity of bufexamac, with a focus on photostability and phototoxicity, by forming an inclusion complex with sulfobutylether-β-cyclodextrin (SBECD). The photobiochemical properties of bufexamac were evaluated by reactive oxygen species (ROS) assay and using in vitro photogenotoxic assessment tools. To assess the inclusion properties of SBECD complex with bufexamac, a UV absorption spectroscopic study was also carried out. The influence of SBECD on the photoreactivity of bufexamac was analyzed by ROS assay and photostability test. From the photobiochemical data, superoxide generation from irradiated bufexamac indicated its photoreactivity; however, the photogenotoxic risk of bufexamac was negligible owing to low DNA-binding affinity and DNA-photocleaving activity. SBECD complex of bufexamac was formed, and the association constant of the complex was calculated to be 620M(-1). On the basis of the photochemical data on bufexamac co-existing with SBECD, ROS generation from irradiated bufexamac (200μM) was inhibited by SBECD at concentrations of over 20μM. The degradation constant of bufexamac in SBECD was decreased ca. 30% compared with that of bufexamac, suggesting improvement of its photostability. The phototoxic risk of bufexamac might be attenuated by SBECD complexation, and cyclodextrin inclusion complexes might be a useful approach for modulating the phototoxicity of drugs. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Thermodynamic analysis of ferulate complexation with α-, β- and γ-cyclodextrins

    International Nuclear Information System (INIS)

    González-Mondragón, Edith; Torralba-González, Armando; García-Gutiérrez, Ponciano; Robles-González, Vania S.; Salazar-Govea, Alma Y.; Zubillaga, Rafael A.

    2016-01-01

    Highlights: • Ferulate exhibits the highest affinity for the β-cyclodextrin. • The β-CD cavity fits better with FER, according to the docking simulations. • The complexation of FER with β-CD is the only one favored by entropy. • More water molecules seem to be displaced after the complexation of FER with β-CD. - Abstract: Isothermal titration calorimetry (ITC) was used to characterize the thermodynamics of the complexation processes of α-, β- and γ-cyclodextrin (CD) with ferulate (FER) in aqueous solutions. The equilibrium constants of ferulate complexation with CDs (K_c, in dm"3 mol"−"1) at pH 9.0 and 25.0 °C were: 176.5 ± 5.0 (β-CD), 53.2 ± 3.4 (α-CD) and 19.4 ± 0.4 (γ-CD). Although FER–β-CD is the tightest complex of the three studied, its binding reaction is also the least exothermic and the only one that is entropically favored. Calculated binding enthalpies, based on the buried surface area upon complexation, are close to those determined by ITC except for the FER–β-CD complex which is more than two times more exothermic. According to these results and those obtained by molecular docking simulations, it is proposed that ferulate binds to the hydrophobic cavity of β-CD, displacing more water molecules than in the other two CD complexes.

  16. Inclusion complex and nanoclusters of cyclodextrin to increase the solubility and efficacy of albendazole.

    Science.gov (United States)

    Pacheco, P A; Rodrigues, L N C; Ferreira, J F S; Gomes, A C P; Veríssimo, C J; Louvandini, H; Costa, R L D; Katiki, L M

    2018-03-01

    Albendazole (ABZ), a benzimidazole widely used to control gastrointestinal parasites, is poorly soluble in water, resulting in variable and incomplete bioavailability. This has favored the appearance ABZ-resistant nematodes and, consequently, an increase in its clinical ineffectiveness. Among the pharmaceutical techniques developed to increase drug efficacy, cyclodextrins (CDs) and other polymers have been extensively used with water-insoluble pharmaceutical drugs to increase their solubility and availability. Our objective was to prepare ABZ formulations, including β-cyclodextrin (βCD) or hydroxypropyl-β-cyclodextrin (HPβCD), associated or not to the water-soluble polymer polyvinylpyrrolidone (PVP). These formulations had their solubility and anthelmintic effect both evaluated in vitro. Also, their anthelmintic efficacy was evaluated in lambs naturally infected with gastrointestinal nematodes (GIN) through the fecal egg count (FEC) reduction test. In vitro, the complex ABZ/HPβCD had higher solubility than ABZ/βCD. The addition of PVP to the complexes increased solubility and dissolution rates more effectively for ABZ/HPβCD than for ABZ/βCD. In vivo, 48 lambs naturally infected with GIN were divided into six experimental groups: control, ABZ, ABZ/βCD, ABZ/βCD-PVP, ABZ/HPβCD, and ABZ/HPβCD-PVP. Each treated animal received 10 mg/kg of body weight (based on the ABZ dose) for three consecutive days. After 10 days of the last administered dose, treatment efficacy was calculated. The efficacy values were as follows: ABZ (70.33%), ABZ/βCD (85.33%), ABZ/βCD-PVP (82.86%), ABZ/HPβCD (78.37%), and ABZ/HPβCD-PVP (43.79%). In vitro, ABZ/HPβCD and ABZ/HPβCD-PVP had high solubility and dissolution rates. In vivo, although the efficacies of ABZ/βCD, ABZ/βCD-PVP, and ABZ/HPβCD increased slightly when compared to pure ABZ, this increase was not significant (P > 0.05).

  17. The three transglycosylation reactions catalyzed by cyclodextrin glycosyltransferase from Bacillus circulans (strain 251) proceed via different kinetic mechanisms

    NARCIS (Netherlands)

    Veen, Bart A. van der; Alebeek, Gert-Jan W.M. van; Uitdehaag, Joost C.M.; Dijkstra, Bauke W.; Dijkhuizen, Lubbert

    Cyclodextrin glycosyltransferase (CGTase) catalyzes three transglycosylation reactions via a double displacement mechanism involving a covalent enzyme-intermediate complex (substituted-enzyme intermediate). Characterization of the three transglycosylation reactions, however, revealed that they

  18. Ligandless Suzuki-Miyaura reaction in neat water with or without native β-cyclodextrin as additive

    KAUST Repository

    Decottignies, Audrey

    2013-02-01

    Efficient green ligand-free Suzuki cross coupling in neat water was developed by using low loading of catalyst (0.5 mol%) in neat water in the presence or not of β-cyclodextrin (0.5 mol%) as additive at 25 C and 100 C respectively. © 2012 Elsevier B.V.

  19. Study in aqueous solution of the praseodymium inclusion in β-cyclodextrin in 2 M of NaCl; Estudio en solucion acuosa de la inclusion del praseodimio en la β-ciclodextrina en 2 M de NaCl

    Energy Technology Data Exchange (ETDEWEB)

    De la Cruz M, N.

    2013-07-01

    In the fission of uranium to produce electricity, generated between the fission products which are the lanthanides and actinides that at any given time may come into contact with aqueous media, because of this, praseodymium was including in the β-cyclodextrin in order to increase the solubility and stability of praseodymium by forming inclusion complexes Praseodymium-β-cyclodextrin (Pr-β-Cd). The inclusion study was conducted in a proportion of praseodymium and β-cyclodextrin. Infrared spectra, Raman and X-ray diffraction showed the presence of praseodymium and β-cyclodextrin in the inclusion complex, in both proportions. The analysis by scanning electron microscopy confirmed the inclusion of praseodymium in βcyclodextrin. In general, the results of characterization obtained by these techniques show the formation of the inclusion complex. Furthermore, the behaviour of praseodymium inclusion in the β-cyclodextrin was studied in 2 M NaCl at 303 K and free-CO{sub 2} conditions. For this reason, we used two methods: spectrophotometric and potentiometric titration direct of praseodymium-β-cyclodextrin, the data were treated graphically and with the program SUPERQUAD, respectively. The values obtained for praseodymium by spectrophotometric method was: log β{sub 1}= -8.75 calculated graphically and with the potentiometric method, using program SUPERQUAD were logβ{sub 1,OH}= -8.73 ± 0.01 logβ{sub 1,2OH}= -18.27 ± 0.16 and logβ{sub 1,3OH}= -26.44 ± 0.02 obtained simultaneously. (Author)

  20. A green synthesis of copper nanoparticles using native cyclodextrins as stabilizing agents

    Directory of Open Access Journals (Sweden)

    Javier Suárez-Cerda

    2017-03-01

    Full Text Available In this work, a comparative study of the effect of the NCD size as a stabilizing agent, on the synthesis of copper nanoparticles (Cu-NPs by an easy green method was reported. The nanoparticles were synthesized through the chemical reduction of aqueous solutions of copper (II sulfate with ascorbic acid, using different native cyclodextrins (NCDs (α-, β-, or γ-NCD as stabilizing agents. Cu-NPs were characterized by scanning electron microscopy–energy dispersive spectroscopy (SEM–EDX, powder X-ray diffraction (XRD and transmission electron microscopy (TEM. The pattern showed in the typical selected area electron diffraction (SAED and lattice fringes, evidence that the crystalline structure of Cu-NPs is face-centered cubic (FCC with a (111, (200 and (220 lattice planes of Cu. The analysis of the TEM images show that the size of the Cu-NPs depends on the type of native cyclodextrin (NCD, also it was observed that the nanoparticles are spherical and with a size between ∼2 and 33 nm. The smaller Cu-NPs were obtained with α-NCD (mode 4 nm, while the nanoparticles obtained with β-NCD show the narrow size distribution (mode 6.5 nm. The average particle size and particle size distribution of Cu-NPs depend upon the type of CDs.

  1. Inclusion Complexes of Sunscreen Agents with β-Cyclodextrin: Spectroscopic and Molecular Modeling Studies

    Directory of Open Access Journals (Sweden)

    Nathir A. F. Al-Rawashdeh

    2013-01-01

    Full Text Available The inclusion complexes of selected sunscreen agents, namely, oxybenzone (Oxy, octocrylene (Oct, and ethylhexyl-methoxycinnamate (Cin with β-cyclodextrin (β-CD were studied by UV-Vis spectroscopy, differential scanning calorimetry (DSC, 13C NMR techniques, and molecular mechanics (MM calculations and modeling. Molecular modeling (MM study of the entire process of the formation of 1 : 1 stoichiometry sunscreen agent/β-cyclodextrin structures has been used to contribute to the understanding and rationalization of the experimental results. Molecular mechanics calculations, together with 13C NMR measurements, for the complex with β-CD have been used to describe details of the structural, energetic, and dynamic features of host-guest complex. Accurate structures of CD inclusion complexes have been derived from molecular mechanics (MM calculations and modeling. The photodegradation reaction of the sunscreen agents' molecules in lotion was explored using UV-Vis spectroscopy. It has been demonstrated that the photostability of these selected sunscreen agents has been enhanced upon forming inclusion complexes with β-CD in lotion. The results of this study demonstrate that β-CD can be utilized as photostabilizer additive for enhancing the photostability of the selected sunscreen agents' molecules.

  2. Enhancing Antidepressant Effect of Poloxamer/Chitosan Thermosensitive Gel Containing Curcumin-Cyclodextrin Inclusion Complex

    Directory of Open Access Journals (Sweden)

    Ye Zhang

    2018-01-01

    Full Text Available Poor solubility and bioavailability are limiting factors for the clinical application of curcumin. This study seeks to develop poloxamer/chitosan thermosensitive gel containing curcumin-cyclodextrin inclusion complex with enhanced brain bioavailability and antidepressant effect. The optimized gel had shorter gelation time and produced sustained release in vitro characterized with non-Fickian diffusion. Pharmacokinetics of gel were evaluated using male Sprague-Dawley rats receiving 240 μg/kg of curcumin and curcumin-cyclodextrin inclusion complex through intranasal administration, compared against a control group receiving intravenous curcumin (240 μg/kg. The intranasal administration of gel provided sustained release by maintaining plasma concentrations of curcumin above 21.27 ± 3.26 ng/mL for up to 8 h. Compared to intranasal administration of the inclusion complex, AUC0–8 h of curcumin from thermoreversible gel in plasma and hippocampus was increased 1.62- and 1.28-fold, respectively. The gel exhibited superior antidepressant activity in mice. The findings reported here suggested that the clinical application of curcumin can be better exploited through an intranasal administration of the thermosensitive gel.

  3. Dynamics and interactions of ibuprofen in cyclodextrin nanosponges by solid-state NMR spectroscopy

    Directory of Open Access Journals (Sweden)

    Monica Ferro

    2017-01-01

    Full Text Available Two different formulations of cyclodextrin nanosponges (CDNS, obtained by polycondensation of β-cyclodextrin with ethylenediaminetetraacetic acid dianhydride (EDTAn, were treated with aqueous solutions of ibuprofen sodium salt (IbuNa affording hydrogels that, after lyophilisation, gave two solid CDNS-drug formulations. 1H fast MAS NMR and 13C CP-MAS NMR spectra showed that IbuNa was converted in situ into its acidic and dimeric form (IbuH after freeze-drying. 13C CP-MAS NMR spectra also indicated that the structure of the nanosponge did not undergo changes upon drug loading compared to the unloaded system. However, the 13C NMR spectra collected under variable contact time cross-polarization (VCT-CP conditions showed that the polymeric scaffold CDNS changed significantly its dynamic regime on passing from the empty CDNS to the drug-loaded CDNS, thus showing that the drug encapsulation can be seen as the formation of a real supramolecular aggregate rather than a conglomerate of two solid components. Finally, the structural features obtained from the different solid-state NMR approaches reported matched the information from powder X-ray diffraction profiles.

  4. Determination of the molecular complexation constant between alprostadil and alpha-cyclodextrin by conductometry: implications for a freeze-dried formulation.

    Science.gov (United States)

    Sheehy, Philip M; Ramstad, Tore

    2005-10-04

    The binding constant between alprostadil (PGE1) and alpha-cyclodextrin (alpha-CD) was determined at four temperatures using conductance measurements. Alpha-cyclodextrin is an excipient material in Caverject dual chamber syringe (DCS) that was added to enhance stability. The binding constant was used to calculate the amount of PGE1 free upon reconstitution and injection, since only the free drug is clinically active. The conductivity measurement is based on a decrease in specific conductance as alprostadil is titrated with alpha-CD. The change in conductivity was plotted versus free ligand concentration (alpha-CD) to generate a binding curve. As the value of the binding constant proved to be dependent on substrate concentration, it is really a pseudo binding constant. A value of 742+/-60 M(-1) was obtained for a 0.5 mM solution of alprostadil at 27 degrees C and a value of 550+/-52 M(-1) at 37 degrees C. These results compare favorably to values previously obtained by NMR and capillary electrophoresis. Calculation of the fraction PGE1 free upon reconstitution and injection show it to approach the desired outcome of one. Hence, the amount of drug delivered by Caverject DCS is nominally equivalent to that delivered by Caverject S. Po., a predecessor product that contains no alpha-cyclodextrin.

  5. Adsorbent for p-phenylenediamine adsorption and removal based on graphene oxide functionalized with magnetic cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dongxue; Liu, Liangliang; Jiang, Xinyu; Yu, Jingang [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Chen, Xiaohong [Collaborative Innovation Center of Resource-conserving & Environment-friendly Society and Ecological Civilization, Changsha, 410083 (China); Chen, Xiaoqing, E-mail: xqchen@csu.edu.cn [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Collaborative Innovation Center of Resource-conserving & Environment-friendly Society and Ecological Civilization, Changsha, 410083 (China)

    2015-02-28

    Highlights: • Magnetic β-cyclodextrin-graphene oxide (MCG) show high adsorption capacity. • The maximum adsorption capacity was 1102.58 mg/g at 45 °C and pH 8. • MCG can be easily and fast extracted from water by magnetic attraction. • Removal rate of MCG could reach 98% after three times of adsorption. • Adsorption capacity of MCG remained at 81% after five cycles. - Abstract: Recently, graphene oxide (GO) based magnetic nanocomposites have been widely used in an adsorption-based process for the removal of organic pollutants from the water system. In this study, magnetic β-cyclodextrin-graphene oxide nanocomposites (MCG) were synthesized according to covalent binding of magnetic β-cyclodextrin nanoparticles onto the GO surface and the as-made nanocomposites were successfully applied as adsorbents for the adsorption and removal of p-phenylenediamines (PPD). The composition and morphology of prepared materials were characterized by Fourier infrared spectrometry (FT-IR), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Effects of pH, temperature, time and reusability on the adsorption of PPD were investigated, as well as the kinetics and isotherms parameters of the adsorbents were determined. The results indicated that the maximum adsorption capacity of MCG was 1102.58 mg/g at 45 °C and pH 8. The adsorption capacity remained at 81% after five cycles. Removal rate could reach 98% after three times of adsorption. The adsorption process with PPD was found that fitted pseudo-second-order kinetics equations and the Langmuir adsorption model. The results showed the MCG had a good adsorption ability to remove organic pollutants in wastewater.

  6. Adsorbent for p-phenylenediamine adsorption and removal based on graphene oxide functionalized with magnetic cyclodextrin

    International Nuclear Information System (INIS)

    Wang, Dongxue; Liu, Liangliang; Jiang, Xinyu; Yu, Jingang; Chen, Xiaohong; Chen, Xiaoqing

    2015-01-01

    Highlights: • Magnetic β-cyclodextrin-graphene oxide (MCG) show high adsorption capacity. • The maximum adsorption capacity was 1102.58 mg/g at 45 °C and pH 8. • MCG can be easily and fast extracted from water by magnetic attraction. • Removal rate of MCG could reach 98% after three times of adsorption. • Adsorption capacity of MCG remained at 81% after five cycles. - Abstract: Recently, graphene oxide (GO) based magnetic nanocomposites have been widely used in an adsorption-based process for the removal of organic pollutants from the water system. In this study, magnetic β-cyclodextrin-graphene oxide nanocomposites (MCG) were synthesized according to covalent binding of magnetic β-cyclodextrin nanoparticles onto the GO surface and the as-made nanocomposites were successfully applied as adsorbents for the adsorption and removal of p-phenylenediamines (PPD). The composition and morphology of prepared materials were characterized by Fourier infrared spectrometry (FT-IR), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Effects of pH, temperature, time and reusability on the adsorption of PPD were investigated, as well as the kinetics and isotherms parameters of the adsorbents were determined. The results indicated that the maximum adsorption capacity of MCG was 1102.58 mg/g at 45 °C and pH 8. The adsorption capacity remained at 81% after five cycles. Removal rate could reach 98% after three times of adsorption. The adsorption process with PPD was found that fitted pseudo-second-order kinetics equations and the Langmuir adsorption model. The results showed the MCG had a good adsorption ability to remove organic pollutants in wastewater

  7. α-Cyclodextrins Polyrotaxane Loading Silver Sulfadiazine

    Directory of Open Access Journals (Sweden)

    Sa Liu

    2018-02-01

    Full Text Available As a drug carrier, polyrotaxane (PR has been used for targeted delivery and sustained release of drugs, whereas silver sulfadiazine (SD-Ag is an emerging antibiotic agent. PR was synthesized by the use of α-cyclodextrin (CD and poly(ethylene glycol (PEG, and a specific antibacterial material (PR-(SD-Ag was then prepared by loading SD-Ag onto PR with different mass ratios. The loading capacity and the encapsulation efficiency were 90% at a mass ratio of 1:1 of PR and SD-Ag. SD-Ag was released stably and slowly within 6 d in vitro, and its cumulative release reached more than 85%. The mechanism of PR loading SD-Ag might be that SD-Ag attached to the edge of α-CD through hydrogen bonding. PR-(SD-Ag showed a higher light stability than SD-Ag and held excellent antibacterial properties against Escherichia coli (E. coli and Staphylococcus aureus (S. aureus.

  8. A novel method of synthesizing cyclodextrin grafted multiwall carbon nanotubes/iron oxides and its adsorption of organic pollutant

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei; Jiang, Xinyu [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Chen, Xiaoqing, E-mail: xqchen@csu.edu.cn [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Collaborative Innovation Center of Resource-conserving and Environment-friendly Society and Ecological Civilization (China)

    2014-11-30

    Highlights: • A cost-effective and one-step method for grafting cyclodextrin onto magnetic material. • Relatively good separation and regeneration properties as adsorbent. • The adsorption capacities are comparable with other adsorbents reported previously. - Abstract: A novel methodology for the synthesis of the multiwalled carbon nanotubes/iron oxides modified by β-cyclodextrin (denoted as MWCNTs/iron oxides/β-CD) was proposed using 1,6-diisocyanatohexane as cross-linker in N,N-dimethyl formamide, which avoided complex steps in the link of β-cyclodextrin and MWCNTs/iron oxides via conventional synthetic methods. The characteristic results of Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and thermogravimetric analysis (TGA) showed that β-CD was grafted onto the MWCNTs/iron oxides successfully. In addition, vibrating sample magnetometer (VSM) and magnetic separation experiment suggested that the prepared composite exhibited preferable magnetic property and good dispersion property in aqueous solution. The effects of contact time, initial adsorbent content, solution pH and temperature on the adsorption of p-nitrophenol (PNP) were studied systematically. The adsorption kinetics and equilibrium isotherms data fitted well with pseudo-second-order kinetic equation and Langmuir isotherm model, respectively. Furthermore, the adsorption-desorption experiment of PNP demonstrated that MWCNTs/iron oxides/β-CD is a cost-effective material with high regeneration efficiency.

  9. Novel {beta}-cyclodextrin modified CdTe quantum dots as fluorescence nanosensor for acetylsalicylic acid and metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Algarra, M. [Centro de Geologia do Porto, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Campos, B.B.; Aguiar, F.R.; Rodriguez-Borges, J.E. [Centro de Investigacao em Quimica (CIQ-UP), Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 169-007 Porto (Portugal); Esteves da Silva, J.C.G., E-mail: jcsilva@fc.up.pt [Centro de Investigacao em Quimica (CIQ-UP), Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 169-007 Porto (Portugal)

    2012-05-01

    {beta}-Cyclodextrin was modified with 11-[(ethoxycarbonyl)thio]undecanoic acid and used as a capping agent, together with mercaptosuccinic acid, to prepare water-stable CdTe quantum dots. The water soluble quantum dot obtained displays fluorescence with a maximum emission at 425 nm (under excitation at 300 nm) with lifetimes of 0.53, 4.8, 181, and 44.1 ns, respectively. The S-{beta}CD-MSA-CdTe can act as a nanoprobe that is due to the affinity of the cyclodextrin moiety for selected substances such as acetylsalicylic acid (ASA) and its metabolites as foreign species. The fluorescence of the S-{beta}CD-MSA-CdTe is enhanced on addition of ASA. Linear calibration plots are observed with ASA in concentrations between 0 and 1 mg/l, with a limit of detection at 8.5 Multiplication-Sign 10{sup -9} mol/l (1.5 ng/ml) and a precision as relative standard deviation of 1% (0.05 mg/l). The interference effect of certain compounds as ascorbic acid and its main metabolites such as salicylic, gentisic and salicyluric acid upon the obtained procedure was studied. Highlights: Black-Right-Pointing-Pointer Nanosensors constituted by CdTe quantum dots capped with modified cyclodextrin. Black-Right-Pointing-Pointer This nanomaterial shows fluorescence properties compatible with a semiconductor quantum dot. Black-Right-Pointing-Pointer The nanosensor shows fluorescence enhancement when inclusion complexes are formed with acetylsalicylic acid. Black-Right-Pointing-Pointer This nanomaterial has nanosensor potential taking into consideration the formation stability of the inclusion complex.

  10. Synthesis and Characterization of β-Cyclodextrin Functionalized Ionic Liquid Polymer as a Macroporous Material for the Removal of Phenols and As(V

    Directory of Open Access Journals (Sweden)

    Muggundha Raoov

    2013-12-01

    Full Text Available β-Cyclodextrin-ionic liquid polymer (CD-ILP was first synthesized by functionalized β-cyclodextrin (CD with 1-benzylimidazole (BIM to form monofunctionalized CD (βCD-BIMOTs and was further polymerized using a toluene diisocyanate (TDI linker to form insoluble CD-ILP (βCD-BIMOTs-TDI. The βCD-BIMOTs-TDI polymer was characterized using various tools and the results obtained were compared with those derived from the native β-cyclodextrin polymer (βCD-TDI. The SEM result shows that the presence of ionic liquid (IL increases the pore size, while the thermo gravimetric analysis (TGA result shows that the presence of IL increases the stability of the polymer. Meanwhile, Brunauer-Emmett-Teller (BET results show that βCD-BIMOTs-TDI polymer has 1.254 m2/g surface areas and the Barret-Joyner-Halenda (BJH pore size distribution result reveals that the polymer exhibits macropores with a pore size of 77.66 nm. Preliminary sorption experiments were carried out and the βCD-BIMOTs-TDI polymer shows enhanced sorption capacity and high removal towards phenols and As(V.

  11. New type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane for gallic acid encapsulation and controlled release.

    Science.gov (United States)

    Paun, Gabriela; Neagu, Elena; Tache, Andreia; Radu, G L

    2014-01-01

    A new type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane have been developed for the encapsulation and controlled release of gallic acid. The morphology of the composite membrane was investigated by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM), whereas swelling gallic acid and release properties were investigated by UV-visible spectroscopy. The release behavior with pH changes was also explored. The composite membrane based on chitosan/2-hydroxypropyl-β-cyclodextrin with gallic acid included showed improved antioxidant capacities compared to plain chitosan membrane. The information obtained in this study will facilitate the design and preparation of composite membrane based on chitosan and could open a wide range of applications, particularly its use as an antioxidant in food, food packaging, biomedical (biodegradable soft porous scaffolds for enhance the surrounding tissue regeneration), pharmaceutical and cosmetics industries.

  12. Ligand-functionalized degradable polyplexes formed by cationic poly(aspartic acid)-grafted chitosan-cyclodextrin conjugates

    Science.gov (United States)

    Song, Hai-Qing; Li, Rui-Quan; Duan, Shun; Yu, Bingran; Zhao, Hong; Chen, Da-Fu; Xu, Fu-Jian

    2015-03-01

    Polypeptide-based degradable polyplexes attracted considerable attention in drug delivery systems. Polysaccharides including cyclodextrin (CD), dextran, and chitosan (CS) were readily grafted with cationic poly(aspartic acid)s (PAsps). To further enhance the transfection performances of PAsp-based polyplexes, herein, different types of ligand (folic acid, FA)-functionalized degradable polyplexes were proposed based on the PAsp-grafted chitosan-cyclodextrin conjugate (CCPE), where multiple β-CDs were tied on a CS chain. The FA-functionalized CCPE (i.e., CCPE-FA) was obtained via a host-guest interaction between the CD units of CCPE and the adamantane (Ad) species of Ad-modified FA (Ad-FA). The resulting CCPE/pDNA, CCPE-FA/pDNA, and ternary CCPE-FA/CCPE/pDNA (prepared by layer-by-layer assembly) polyplexes were investigated in detail using different cell lines. The CCPE-based polyplexes displayed much higher transfection efficiencies than the CS-based polyplexes reported earlier by us. The ternary polyplexes of CCPE-FA/CCPE/pDNA produced excellent gene transfection abilities in the folate receptor (FR)-positive tumor cells. This work would provide a promising means to produce highly efficient polyplexes for future gene therapy applications.Polypeptide-based degradable polyplexes attracted considerable attention in drug delivery systems. Polysaccharides including cyclodextrin (CD), dextran, and chitosan (CS) were readily grafted with cationic poly(aspartic acid)s (PAsps). To further enhance the transfection performances of PAsp-based polyplexes, herein, different types of ligand (folic acid, FA)-functionalized degradable polyplexes were proposed based on the PAsp-grafted chitosan-cyclodextrin conjugate (CCPE), where multiple β-CDs were tied on a CS chain. The FA-functionalized CCPE (i.e., CCPE-FA) was obtained via a host-guest interaction between the CD units of CCPE and the adamantane (Ad) species of Ad-modified FA (Ad-FA). The resulting CCPE/pDNA, CCPE

  13. Cyclodextrin-Based [1]Rotaxanes on Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Yanli Zhao

    2012-08-01

    Full Text Available Transformation of mechanically interlocked molecules (e.g., rotaxanes and catenanes into nanoscale materials or devices is an important step towards their real applications. In our current work, an azobenzene-modified β-cyclodextrin (β-CD derivative that can form a self-inclusion complex in aqueous solution was prepared. The self-included β-CD derivative was then functionalized onto a gold nanoparticle (AuNP surface via a ligand-exchange reaction in aqueous solution, leading to the formation of AuNP-[1]rotaxane hybrids. Corresponding non-self-included β-CD derivative functionalized AuNPs were also developed in a DMF/H2O mixture solution for control experiments. These hybrids were fully characterized by UV-vis and circular dichroism spectroscopies, together with transmission electron microscopy (TEM. The competitive binding behavior of the hybrids with an adamantane dimer was investigated.

  14. Cyclodextrin derivatives with cyanohydrin and carboxylate groups as artificial glycosidases

    DEFF Research Database (Denmark)

    Bols, Mikael; Ortega-Caballero, Fernando

    2006-01-01

    Two cyclodextrin derivatives (1 and 2) were prepared in an attempt to create glycosidase mimics with a general acid catalyst and a nucleophilic carboxylate group. The catalysts 1 and 2 were found to catalyse the hydrolysis of 4-nitrophenyl beta-D-glucopyranoside at pH 8.0, but rapidly underwent...... decomposition with loss of hydrogen cyanide to convert the cyanohydrin to the corresponding aldehyde. The initial rate of the catalysis shows that the cyanohydrin group in these molecules functions as a good catalyst, but that the carboxylate has no positive effect. The decomposition product aldehydes display...

  15. Copolymerization preparation of cationic cyclodextrin chiral stationary phases for drug enantioseparation in chromatography

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Ren-Qi Wang, Teng-Teng Ong, Ke Huang, Weihua Tang & Siu-Choon Ng ### Abstract We described a facile and effective protocol wherein radical copolymerization is employed to covalently bond cationic β-cyclodextrin (β-CD) onto silica particles with extended linkage, resulting in a chiral stationary phase (IMPCSP) that can be used for the enantioseparation of racemic drugs in both high-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). Starting ...

  16. Thermodynamic analysis of ferulate complexation with α-, β- and γ-cyclodextrins

    Energy Technology Data Exchange (ETDEWEB)

    González-Mondragón, Edith, E-mail: edith@mixteco.utm.mx [Universidad Tecnológica de la Mixteca, C.P. 69000 Huajuapan de León, Oax. (Mexico); Torralba-González, Armando [Universidad Tecnológica de la Mixteca, C.P. 69000 Huajuapan de León, Oax. (Mexico); García-Gutiérrez, Ponciano [Departamento de Química, Universidad Autónoma Metropolitana – Iztapalapa, Apartado Postal 55-534, Iztapalapa, C.P. 09340 México, D.F. (Mexico); Robles-González, Vania S.; Salazar-Govea, Alma Y. [Universidad Tecnológica de la Mixteca, C.P. 69000 Huajuapan de León, Oax. (Mexico); Zubillaga, Rafael A., E-mail: zlra@xanum.uam.mx [Departamento de Química, Universidad Autónoma Metropolitana – Iztapalapa, Apartado Postal 55-534, Iztapalapa, C.P. 09340 México, D.F. (Mexico)

    2016-06-20

    Highlights: • Ferulate exhibits the highest affinity for the β-cyclodextrin. • The β-CD cavity fits better with FER, according to the docking simulations. • The complexation of FER with β-CD is the only one favored by entropy. • More water molecules seem to be displaced after the complexation of FER with β-CD. - Abstract: Isothermal titration calorimetry (ITC) was used to characterize the thermodynamics of the complexation processes of α-, β- and γ-cyclodextrin (CD) with ferulate (FER) in aqueous solutions. The equilibrium constants of ferulate complexation with CDs (K{sub c}, in dm{sup 3} mol{sup −1}) at pH 9.0 and 25.0 °C were: 176.5 ± 5.0 (β-CD), 53.2 ± 3.4 (α-CD) and 19.4 ± 0.4 (γ-CD). Although FER–β-CD is the tightest complex of the three studied, its binding reaction is also the least exothermic and the only one that is entropically favored. Calculated binding enthalpies, based on the buried surface area upon complexation, are close to those determined by ITC except for the FER–β-CD complex which is more than two times more exothermic. According to these results and those obtained by molecular docking simulations, it is proposed that ferulate binds to the hydrophobic cavity of β-CD, displacing more water molecules than in the other two CD complexes.

  17. Use of cyclodextrins as a cosmetic delivery system for fragrance materials: linalool and benzyl acetate.

    Science.gov (United States)

    Numanoğlu, Ulya; Sen, Tangül; Tarimci, Nilüfer; Kartal, Murat; Koo, Otilia M Y; Onyüksel, Hayat

    2007-10-19

    The aim of this study was to increase the stability and water solubility of fragrance materials, to provide controlled release of these compounds, and to convert these substances from liquid to powder form by preparing their inclusion complexes with cyclodextrins (CDs). For this purpose, linalool and benzyl acetate were chosen as the fragrance materials. The use of beta-cyclodextrin (beta CD) and 2-hydroxypropyl-beta-cyclodextrin (2-HP beta CD) for increasing the solubility of these 2 fragrance materials was studied. Linalool and benzyl acetate gave a B-type diagram with beta CD, whereas they gave an A(L)-type diagram with 2-HP beta CD. Therefore, complexes of fragrance materials with 2-HP beta CD at 1:1 and 1:2 molar ratios (guest:host) were prepared. The formation of inclusion complexes was confirmed using proton nuclear magnetic resonance ((1)H-NMR) spectroscopy and circular dichroism spectroscopy. The results of the solubility studies showed that preparing the inclusion complex with 2-HP beta CD at a 1:1 molar ratio increased the solubility of linalool 5.9-fold and that of benzyl acetate 4.2-fold, whereas the complexes at a 1:2 molar ratio increased the solubility 6.4- and 4.5-fold for linalool and benzyl acetate, respectively. The stability and in vitro release studies were performed on the gel formulations prepared using uncomplexed fragrance materials or inclusion complexes of fragrance materials at a 1:1 molar ratio. It was observed that the volatility of both fragrance materials was decreased by preparing the inclusion complexes with 2-HP beta CD. Also, in vitro release data indicated that controlled release of fragrances could be possible if inclusion complexes were prepared.

  18. Thermodynamic studies of drug–α-cyclodextrin interactions in water at 298.15 K: Procaine hydrochloride/lidocaine hydrochloride/tetracaine hydrochloride/ranitidine hydrochloride + α-cyclodextrin + H2O systems

    International Nuclear Information System (INIS)

    Shaikh, Vasim R.; Terdale, Santosh S.; Hundiwale, Dilip G.; Patil, Kesharsingh J.

    2014-01-01

    Graphical abstract: The encapsulation of guest tetracaine hydrochloride TC·HCl (C 15 H 24 N 2 O 2 ·HCl), in α-cyclodextrin cavities in aqueous solutions at 298.15 K. -- Highlights: • The osmotic coefficient measurements are reported for PC·HCl/LC·HCl/TC·HCl/RT·HCl + 0.1 m α-CD + water at 298.15 K. • The concentration variation of mean activity coefficients of drug molecules in water–α-CD solutions has been studied. • The transfer Gibbs free energies have been calculated using the activity data. • Pair and triplet interaction parameters and equilibrium constant (log K) values are also estimated. • The results are discussed with emphasis on host–guest interaction concepts. -- Abstract: The osmotic coefficient measurements have been carried out for ternary aqueous solutions containing a fixed concentration of α-cyclodextrin (α-CD) of ∼0.1 mol · kg −1 and varying the concentrations (∼0.012 to ∼0.21 mol · kg −1 ) of drugs Procaine hydrochloride (PC·HCl), Lidocaine hydrochloride (LC·HCl), Tetracaine hydrochloride (TC·HCl) and Ranitidine hydrochloride (RT·HCl) at 298.15 K using vapour pressure osmometry. The water activities for each ternary system were measured and used to obtain the activity coefficients of α-cyclodextrin (α-CD) and drugs following the methodology developed by Robinson and Stokes for isopiestic measurements. The transfer Gibbs free energies of electrolyte (or drug) from water to an aqueous nonelectrolyte (α-CD) solutions (ΔG tr E ) and that of nonelectrolyte (α-CD) from water to an aqueous electrolyte (or drug) solutions (ΔG tr N ) have been calculated using the activity data. These were further used for the estimation of pair and triplet interaction parameters. By applying the method based on the application of the McMillan–Mayer theory of virial coefficients to transfer free energy data, the salting constant (k s ) values have been estimated at 298.15 K. The equilibrium constant (log K) values for the

  19. Photodynamic effects induced by meso-tris(pentafluorophenyl)corrole and its cyclodextrin conjugates on cytoskeletal components of HeLa cells.

    Science.gov (United States)

    Barata, Joana F B; Zamarrón, Alicia; Neves, M Graça P M S; Faustino, M Amparo F; Tomé, Augusto C; Cavaleiro, José A S; Röder, Beate; Juarranz, Ángeles; Sanz-Rodríguez, Francisco

    2015-03-06

    The aim of this work was to synthesize new corrole β-cyclodextrin conjugates βCD1 (with one β-cyclodextrin moiety) and βCD2 (with two β-cyclodextrin moieties) from 5,10,15-tris(pentafluorophenyl)corrole (TPFC) and to test in vitro the efficacy of these compounds towards tumoral HeLa cells. No dark cytotoxicity was observed for TPFC and βCD1 at the concentration used for PDT cell treatment, even during long incubation periods (24 h). Fluorescence microscopy showed that TPFC and βCD1 accumulate in HeLa cells at lysosomes and in the Golgi apparatus, respectively. The cell survival after the PDT treatment with visible light was dependent on light exposure level and compound concentration. βCD1 was able to penetrate efficiently in the cytoplasm of the HeLa cells. In particular, we have analyzed the photodynamic effect of the corrole derivatives on the microtubules of HeLa cells and the morphological alterations on the mitotic spindle. TPFC and βCD1 caused photocytotoxicity in tumoral HeLa cells and induced a rapid metaphase blockage of cells that also showed clearly altered configurations of the mitotic spindle. The results showed that TPFC has the highest photosensitizing efficiency on tumoral cells. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  20. Gas-liquid partitioning of halogenated volatile organic compounds in aqueous cyclodextrin solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ondo, Daniel; Barankova, Eva [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dohnal, Vladimir, E-mail: dohnalv@vscht.cz [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic)

    2011-08-15

    Highlights: > Binding of halogenated VOCs with cyclodextrins examined through g-l partitioning. > Complex stabilities reflect host-guest size matching and hydrophobic interaction. > Presence of halogens in the guest molecule stabilizes the binding. > Thermodynamic origin of the binding varies greatly among the systems studied. > Results obey the guest-CD global enthalpy-entropy compensation relationship. - Abstract: Gas-liquid partitioning coefficients (K{sub GL}) were measured for halogenated volatile organic compounds (VOCs), namely 1-chlorobutane, methoxyflurane, pentafluoropropan-1-ol, heptafluorobutan-1-ol, {alpha},{alpha},{alpha}-trifluorotoluene, and toluene in aqueous solutions of natural {alpha}-, {beta}-, and {gamma}-cyclodextrins (CDs) at temperatures from (273.35 to 326.35) K employing the techniques of headspace gas chromatography and inert gas stripping. The binding constants of the 1:1 inclusion complex formation between the VOCs and CDs were evaluated from the depression of the VOCs volatility as a function of CD concentration. The host-guest size matching and the hydrophobic interaction concept were used to rationalize the observed widely different affinity of the VOC-CD pairs to form the inclusion complex. The enthalpic and entropic component of the standard Gibbs free energy of complex formation as derived from the temperature dependence of the binding constant indicate the thermodynamic origin of the binding to vary greatly among the systems studied, but follow the global enthalpy-entropy compensation relationships reported previously in the literature.

  1. Evaluation of antitumor effects of folate-conjugated methyl-β-cyclodextrin in melanoma.

    Science.gov (United States)

    Motoyama, Keiichi; Onodera, Risako; Tanaka, Nao; Kameyama, Kazuhisa; Higashi, Taishi; Kariya, Ryusho; Okada, Seiji; Arima, Hidetoshi

    2015-01-01

    Melanoma is a life-threatening disorder and its incidence is increasing gradually. Despite the numerous treatment approaches, conventional systemic chemotherapy has not reduced the mortality rate among melanoma patients, probably due to the induction of toxicity to normal tissues. Recently, we have developed folate-conjugated methyl-β-cyclodextrin (FA-M-β-CyD) and clarified its potential as a new antitumor agent involved in autophagic cell death. However, it remains uncertain whether FA-M-β-CyD exerts anticancer effects against melanomas. Therefore, in this study, we investigated the effects of FA-M-β-CyD on the folate receptor-α (FR-α)-expressing melanoma cell-selective cytotoxic effect. FA-M-β-CyD showed cytotoxic effects in Ihara cells, a human melanoma cell line expressing FR-α. In sharp contrast to methyl-β-cyclodextrin, FA-M-β-CyD entered Ihara cells [FR-α(+)] through FR-α-mediated endocytosis. Additionally, FA-M-β-CyD elicited the formation of autophagosomes in Ihara cells. Notably, FA-M-β-CyD suppressed melanoma growth in BALB/c nude recombinase-activating gene-2 (Rag-2)/Janus kinase 3 (Jak3) double deficient mice bearing Ihara cells. Therefore, these results suggest that FA-M-β-CyD could be utilized as a potent anticancer agent for melanoma chemotherapy by regulating autophagy.

  2. Thin sensing layer based on semi-conducting β-cyclodextrin rotaxane for toxic metals detection

    Energy Technology Data Exchange (ETDEWEB)

    Teka, S.; Gaied, A.; Jaballah, N. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Université de Monastir, Faculté des Sciences de Monastir, Bd. de l' Environnement, 5019 Monastir (Tunisia); Xiaonan, S. [Université Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086 CNRS, 15 rue J-A de Baı̈ f, 75205 Paris Cedex 13 (France); Majdoub, M., E-mail: mustapha.majdoub@fsm.rnu.tn [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Université de Monastir, Faculté des Sciences de Monastir, Bd. de l' Environnement, 5019 Monastir (Tunisia)

    2016-02-15

    Highlights: • Microwave-assisted synthesis of rotaxane based on anthracene and β-cyclodextrin. • Morphological and optical characterization of thin solid film. • Elaboration of impedimetric gold/rotaxane sensor. • Investigation of the membrane sensitivity towards Hg{sup 2+}, Cu{sup 2+} and Pb{sup 2+} cations. - Abstract: An impedimetric sensor based on a new semi-conducting rotaxane has been described for detection of toxic cations. The rotaxane, consists on a π-conjugated material encapsulated into β-cyclodextrin (β-CD); it has been synthesized via the Williamson reaction under microwaves irradiation. The supramolecular structure of the compound was confirmed by NMR and FT-IR spectroscopies. A thin solid film of the rotaxane was deposited by spin-coating to develop a new electrochemical sensor. The morphological properties of the organic membrane were evaluated using contact angle measurements and atomic force microscopy. The gold/rotaxane/solution interfaces were investigated by electrochemical impedance spectroscopy and the obtained data were fitted using an equivalent electrical circuit. The response of the gold/rotaxane membrane towards Hg{sup 2+}, Cu{sup 2+} and Pb{sup 2+} cations was studied and the results showed a good sensitivity to the mercury cations.

  3. Design and application of cationic amphiphilic β-cyclodextrin derivatives as gene delivery vectors

    Science.gov (United States)

    Wan, Ning; Huan, Meng-Lei; Ma, Xi-Xi; Jing, Zi-Wei; Zhang, Ya-Xuan; Li, Chen; Zhou, Si-Yuan; Zhang, Bang-Le

    2017-11-01

    The nano self-assembly profiles of amphiphilic gene delivery vectors could improve the density of local cationic head groups to promote their DNA condensation capability and enhance the interaction between cell membrane and hydrophobic tails, thus increasing cellular uptake and gene transfection. In this paper, two series of cationic amphiphilic β-cyclodextrin (β-CD) derivatives were designed and synthesized by using 6-mono-OTs-β-CD (1) as the precursor to construct amphiphilic gene vectors with different building blocks in a selective and controlled manner. The effect of different type and degree of cationic head groups on transfection and the endocytic mechanism of β-CD derivatives/DNA nanocomplexes were also investigated. The results demonstrated that the designed β-cyclodextrin derivatives were able to compact DNA to form stable nanocomplexes and exhibited low cytotoxicity. Among them, PEI-1 with PEI head group showed enhanced transfection activity, significantly higher than commercially available agent PEI25000 especially in the presence of serum, showing potential application prospects in clinical trials. Moreover, the endocytic uptake mechanism involved in the gene transfection of PEI-1 was mainly through caveolae-mediated endocytosis, which could avoid the lysosomal degradation of loaded gene, and had great importance for improving gene transfection activity.

  4. Adamantane-bearing benzylamines and benzylamides: novel building blocks for supramolecular systems with finely tuned binding properties towards β-cyclodextrin

    Czech Academy of Sciences Publication Activity Database

    Rouchal, M.; Matelová, A.; de Carvalho, F. P.; Bernat, R.; Grbić, D.; Kuřitka, I.; Babinský, M.; Marek, R.; Čmelík, Richard; Vícha, R.

    2013-01-01

    Roč. 25, č. 6 (2013), s. 349-361 ISSN 1061-0278 Institutional support: RVO:68081715 Keywords : host-guest system * cyclodextrins * adamantane Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.132, year: 2013

  5. SPECTROPHOTOMETRIC STUDIES OF SANGUINARINE-Β-CYCLODEXTRIN COMPLEX FORMATION

    Directory of Open Access Journals (Sweden)

    Veaceslav Boldescu

    2008-06-01

    Full Text Available The main aim of this study was to investigate the influence of pH and the presence of hydrophilic polymer polyvinylpyrrolidone on the formation of sanguinarine-β-cyclodextrin (SANG-β-CD inclusion complex. Spectrophotometric studies of the SANG-β-CD systems in the presence and without 0.1 % PVP at the pH 5.0 did not show any evidence of the complex formation. However, the same systems showed several obvious evidences at the pH 8.0: the hyperchromic and the hypochromic effects and the presence of the isosbestic point in the region of 200 – 210 nm. The association constants calculated by three linear methods: Benesi-Hildebrand, Scott and Scatchard, were two times higher for the systems with addition of 0.1% PVP than for the systems without it.

  6. Enabling technologies and green processes in cyclodextrin chemistry

    Directory of Open Access Journals (Sweden)

    Giancarlo Cravotto

    2016-02-01

    Full Text Available The design of efficient synthetic green strategies for the selective modification of cyclodextrins (CDs is still a challenging task. Outstanding results have been achieved in recent years by means of so-called enabling technologies, such as microwaves, ultrasound and ball mills, that have become irreplaceable tools in the synthesis of CD derivatives. Several examples of sonochemical selective modification of native α-, β- and γ-CDs have been reported including heterogeneous phase Pd- and Cu-catalysed hydrogenations and couplings. Microwave irradiation has emerged as the technique of choice for the production of highly substituted CD derivatives, CD grafted materials and polymers. Mechanochemical methods have successfully furnished greener, solvent-free syntheses and efficient complexation, while flow microreactors may well improve the repeatability and optimization of critical synthetic protocols.

  7. Determination of stability constants of tauro- and glyco-conjugated bile salts with the negatively charged sulfobutylether-β-cyclodextrin: comparison of affinity capillary electrophoresis and isothermal titration calorimetry and thermodynamic analysis of the interaction

    DEFF Research Database (Denmark)

    Holm, René; Østergaard, Jesper; Schönbeck, Jens Christian Sidney

    2014-01-01

    The aim of the present work was to investigate the interaction between bile salts present in the intestine of man, dog and rat with the negatively charged cyclodextrin (CD), sulfobutylether-β-cyclodextrin (SBEβCD). The interactions between bile salts and CDs are of importance for the release of C...

  8. Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

    Directory of Open Access Journals (Sweden)

    Shintaro Kawano

    2015-11-01

    Full Text Available Background: Emulsions stabilized by colloidal particles are known as Pickering emulsions. To date, soft microgel particles as well as inorganic and organic particles have been utilized as Pickering emulsifiers. Although cyclodextrin (CD works as an attractive emulsion stabilizer through the formation of a CD–oil complex at the oil–water interface, a high concentration of CD is normally required. Our research focuses on an effective Pickering emulsifier based on a soft colloidal CD polymer (CD nanogel with a unique surface-active property.Results: CD nanogels were prepared by crosslinking heptakis(2,6-di-O-methyl-β-cyclodextrin with phenyl diisocyanate and subsequent immersion of the resulting polymer in water. A dynamic light scattering study shows that primary CD nanogels with 30–50 nm diameter assemble into larger CD nanogels with 120 nm diameter by an increase in the concentration of CD nanogel from 0.01 to 0.1 wt %. The CD nanogel has a surface-active property at the air–water interface, which reduces the surface tension of water. The CD nanogel works as an effective Pickering emulsion stabilizer even at a low concentration (0.1 wt %, forming stable oil-in-water emulsions through interfacial adsorption by the CD nanogels.Conclusion: Soft CD nanogel particles adsorb at the oil–water interface with an effective coverage by forming a strong interconnected network and form a stable Pickering emulsion. The adsorption property of CD nanogels on the droplet surface has great potential to become new microcapsule building blocks with porous surfaces. These microcapsules may act as stimuli-responsive nanocarriers and nanocontainers.

  9. Hydroxypropyl-beta-cyclodextrin as non-exhaustive extractant for organochlorine pesticides and polychlorinated biphenyls in muck soil

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Fiona [Centre for Atmospheric Research Experiments, Science and Technology Branch, Environment Canada, 6248 Eighth Line, Egbert, Ontario, L0L 1N0 (Canada); Department of Chemistry, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4 (Canada); Bidleman, Terry F., E-mail: terry.bidleman@ec.gc.c [Centre for Atmospheric Research Experiments, Science and Technology Branch, Environment Canada, 6248 Eighth Line, Egbert, Ontario, L0L 1N0 (Canada)

    2010-05-15

    Hydroxypropyl-beta-cyclodextrin (HPCD) was used as a non-exhaustive extractant for organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) in muck soil. An optimized extraction method was developed which involved using a HPCD to soil mass ratio of 5.8 with a single extraction period of 20 h. An aging experiment was performed by spiking a muck soil with {sup 13}C-labeled OCs and non-labeled PCBs. The soil was extracted with the optimized HPCD method and Soxhlet apparatus with dichloromethane over 550 d periodically. The HPCD extractability of the spiked OCs was greater than of the native OCs. A decreased in HPCD extractability was observed for the spiked OCs after 550 d of aging and their extractability approached those of the natives. The partition coefficient between HPCD and soil (log K{sub CD-Soil}) was negatively correlated with the octanol-water partition coefficient (log K{sub OW}) with r{sup 2} = 0.67 and p < 0.05. - The effect of aging on the extractability of organochlorine chemicals in muck soil was investigated using hydroxypropyl-beta-cyclodextrin as a mild extractant.

  10. Design and optimization of novel paclitaxel-loaded folate-conjugated amphiphilic cyclodextrin nanoparticles.

    Science.gov (United States)

    Erdoğar, Nazlı; Esendağlı, Güneş; Nielsen, Thorbjorn T; Şen, Murat; Öner, Levent; Bilensoy, Erem

    2016-07-25

    As nanomedicines are gaining momentum in the therapy of cancer, new biomaterials emerge as alternative platforms for the delivery of anticancer drugs with bioavailability problems. In this study, two novel amphiphilic cyclodextrins (FCD-1 and FCD-2) conjugated with folate group to enable active targeting to folate positive breast tumors were introduced. The objective of this study was to develop and characterize new folated-CD nanoparticles via 3(2) factorial design for optimal final parameters. Full physicochemical characterization studies were performed. Blank and paclitaxel loaded FCD-1 and FCD-2 nanoparticles remained within the range of 70-275nm and 125-185nm, respectively. Zeta potential values were neutral and -20mV for FCD-1 and FCD-2 nanoparticles, respectively. Drug release studies showed initial burst release followed by a longer sustained release. Blank nanoparticles had no cytotoxicity against L929 cells. T-47D and ZR-75-1 human breast cancer cells with different levels of folate receptor expression were used to assess anti-cancer efficacy. Through targeting the folate receptor, these nanoparticles were efficiently engulfed by the breast cancer cells. Additionally, breast cancer cells became more sensitive to cytotoxic and/or cytostatic effects of PCX delivered by FCD-1 and FCD-2. In conclusion, these novel folate-conjugated cyclodextrin nanoparticles can therefore be considered as promising alternative systems for safe and effective delivery of paclitaxel with a folate-dependent mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Cyclodextrin-insulin complex encapsulated polymethacrylic acid based nanoparticles for oral insulin delivery.

    Science.gov (United States)

    Sajeesh, S; Sharma, Chandra P

    2006-11-15

    Present investigation was aimed at developing an oral insulin delivery system based on hydroxypropyl beta cyclodextrin-insulin (HPbetaCD-I) complex encapsulated polymethacrylic acid-chitosan-polyether (polyethylene glycol-polypropylene glycol copolymer) (PMCP) nanoparticles. Nanoparticles were prepared by the free radical polymerization of methacrylic acid in presence of chitosan and polyether in a solvent/surfactant free medium. Dynamic light scattering (DLS) experiment was conducted with particles dispersed in phosphate buffer (pH 7.4) and size distribution curve was observed in the range of 500-800 nm. HPbetaCD was used to prepare non-covalent inclusion complex with insulin and complex was analyzed by Fourier transform infrared (FTIR) and fluorescence spectroscopic studies. HPbetaCD complexed insulin was encapsulated into PMCP nanoparticles by diffusion filling method and their in vitro release profile was evaluated at acidic/alkaline pH. PMCP nanoparticles displayed good insulin encapsulation efficiency and release profile was largely dependent on the pH of the medium. Enzyme linked immunosorbent assay (ELISA) study demonstrated that insulin encapsulated inside the particles was biologically active. Trypsin inhibitory effect of PMCP nanoparticles was evaluated using N-alpha-benzoyl-L-arginine ethyl ester (BAEE) and casein as substrates. Mucoadhesive studies of PMCP nanoparticles were conducted using freshly excised rat intestinal mucosa and the particles were found fairly adhesive. From the preliminary studies, cyclodextrin complexed insulin encapsulated mucoadhesive nanoparticles appear to be a good candidate for oral insulin delivery.

  12. Photophysical and photoprototropic characteristics of phenothiazine in aqueous and β-cyclodextrin media

    Energy Technology Data Exchange (ETDEWEB)

    Rajamohan, Rajaram, E-mail: rajmohanau@gmail.com [Department of Chemistry, S.K.P Institute of Technology, Tiruvannamalai 606611 (India); Nayaki, Sundararajulu Kothai [Chemistry Section, FEAT, Annamalai University, Annamalainagar 608002 (India); Sivakumar, Krishnamoorthy [Department of Chemistry, SCSV University, Enathur, Kanchipuram 631561 (India); Swaminathan, Meenakshisundaram [Department of Chemistry, Annamalai University, Annamalainagar 608002 (India)

    2015-12-15

    The photophysical and photoprototropic characteristics of phenothiazine (PTZ) in aqueous and β-cyclodextrin (β-CD) media have been investigated using absorption, steady state and time resolved fluorescence measurements. The absorbance and fluorescence intensities of the neutral and monocationic forms of PTZ are enhanced by the addition of β-cyclodextrin and it is due to the formation of 1:1 inclusion complex. The formation of complex is confirmed by the decay analysis and Job's continuous variation method in the liquid state while FT-IR spectral study and SEM image analysis in the solid state. The peak and pK{sub a}* values of PTZ in aqueous media are higher than in β-CD medium, which reveals that the >NH group of PTZ lies in the β-CD cavity. - Highlights: • Increase in the absorbance and fluorescence intensity of PTZ by the addition of β-CDx is confirmed the complex formation. • Biexponential decay is noticed for PTZ by the addition of β-CDx is due to the formation of inclusion complex. • FT-IR and SEM images analysis confirms complex between PTZ and β-CDx in solid state. • The pK{sub a} and pK{sub a}* values of PTZ in aqueous medium is higher than in β-CDx medium, which reveals that the >NH group of PTZ lies in the β-CDx cavity. • The orientation of the inclusion complex is proposed by PatchDock server.

  13. Hydration Differences Explain the Large Variations in the Complexation Thermodynamics of Modified γ-Cyclodextrins with Bile Salts

    DEFF Research Database (Denmark)

    Køhler, Jonatan; Schönbeck, Jens Christian Sidney; Westh, Peter

    2016-01-01

    The structure and thermodynamics of inclusion complexes of seven different γ-cyclodextrins (γCDs) and three biologically relevant bile salts (BS) were investigated in the present study. Natural γCD and six modified γCDs [two methyl-γCDs, one sulfobutyl ether-γCD (SBEγCD), and three 2-hydroxypropyl...

  14. Development and Validation Dissolution Analytical Method of Nimesulide beta-Cyclodextrin 400 mg Tablet

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Carvalho Pereira

    2016-10-01

    Full Text Available The nimesulide (N-(4-nitro-2-phenoxyphenylmethanesulfonamide belongs to the class of non-steroidal anti-inflammatory drugs (NSAIDs and category II of the biopharmaceutical classification, The complexation of nimesulide with b-cyclodextrin is a pharmacological strategy to increase the solubility of the drug The objective of this study was to develop and validate an analytical methodology for dissolving the nimesulide beta-cyclodextrin 400 mg tablet and meets the guidelines of ANVISA for drug registration purposes. Once developed, the dissolution methodology was validated according to the RE of parameters no.  899/2003. In the development of the method it was noted that the duration of the dissolution test was 60 minutes, the volume and the most suitable dissolution medium was 900 mL of aqueous solution of sodium lauryl sulfate 1% (w/ v. It was also noted that rotation of 100 rpm and the paddle apparatus was the most appropriate to evaluate the dissolution of the drug. Spectrophotometric methodology was used to quantify the percentage of dissolved drug. The wavelength was 390 nm using the quantification. The validation of the methodology, system suitability parameters, specificity/selectivity, linearity, precision, accuracy and robustness were satisfactory and proved that the developed dissolution methodology was duly executed. DOI: http://dx.doi.org/10.17807/orbital.v8i5.827

  15. Properties and recent applications of cyclodextrins; Propriedades e aplicacoes recentes das ciclodextrinas

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, Cristina de Garcia; Nicolini, Jaqueline; Machado, Clodoaldo; Machado, Vanderlei Gageiro [Univesidade Regional de Blumenau, SC (Brazil)]. E-mail: gageiro@furb.br

    2008-07-01

    Cyclodextrins (CDs) are cyclic oligosaccharides comprised of six or more glucose units connected by alpha-1,4 bonds. They have hydrophobic cavities with a hydrophilic exterior, and are versatile receptors for a variety of substrates. This ability allows them to be applied in many fields, as distinct as supramolecular chemistry, nanotechnology, pharmaceuticals, green chemistry, agrochemicals, analytical chemistry, toiletries, foods, and cosmetics. This review summarizes several aspects related to the physico-chemical properties of CDs and discusses their potential applications illustrated by recent examples. The prospects for their use in several areas are also described. (author)

  16. Antibacterial effect of novel synthesized sulfated β-cyclodextrin crosslinked cotton fabric and its improved antibacterial activities with ZnO, TiO2 and Ag nanoparticles coating.

    Science.gov (United States)

    Selvam, S; Rajiv Gandhi, R; Suresh, J; Gowri, S; Ravikumar, S; Sundrarajan, M

    2012-09-15

    Sulfated β-cyclodextrin was synthesized from sulfonation of β-cyclodextrin and sulfated polymer was crosslinked with cotton fabric using ethylenediaminetetraacetic acid as crosslinker. ZnO, TiO(2) and Ag nanoparticles were prepared and characterized by XRD, UV, DLS, SEM and PSA. The prepared nanoparticles were coated on crosslinked cotton fabric. The crosslinking and nanoparticles coating effects of cotton fabrics were studied by FTIR and SEM analysis. The antibacterial test was done against gram positive Staphylococcus aureus and gram negative Escherichia coli bacterium. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Beta-Cyclodextrin Duplexes That Are Connected through Two Disulfide Bonds: Potent Hosts for the Complexation of Organic Molecules

    Czech Academy of Sciences Publication Activity Database

    Grishina, Anastasia; Stanchev, Stancho; Kumprecht, Lukáš; Buděšínský, Miloš; Pojarová, Michaela; Dušek, Michal; Rumlová, Michaela; Křížová, Ivana; Rulíšek, Lubomír; Kraus, Tomáš

    2012-01-01

    Roč. 18, č. 39 (2012), s. 12292-12304 ISSN 0947-6539 Grant - others:AV ČR(CZ) M200550904 Institutional support: RVO:61388963 ; RVO:68378271 Keywords : cucurbiturils * cyclodextrins * duplexes * host-guest systems * sulfur Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.831, year: 2012

  18. Co-grinding Effect on Crystalline Zaltoprofen with ?-cyclodextrin/Cucurbit[7]uril in Tablet Formulation

    OpenAIRE

    Li, Shanshan; Lin, Xiang; Xu, Kailin; He, Jiawei; Yang, Hongqin; Li, Hui

    2017-01-01

    This work aimed to investigate the co-grinding effects of ?-cyclodextrin (?-CD) and cucurbit[7]uril (CB[7]) on crystalline zaltoprofen (ZPF) in tablet formulation. Crystalline ZPF was prepared through anti-solvent recrystallization and fully analyzed through single-crystal X-ray diffraction. Co-ground dispersions and mono-ground ZPF were prepared using a ball grinding process. Results revealed that mono-ground ZPF slightly affected the solid state, solubility, and dissolution of crystalline Z...

  19. In vitro fermentation characteristics, in vivo ileal and total tract nutrient digestibilities, and fecal microbiota responses of dogs to α-cyclodextrin.

    Science.gov (United States)

    Guevara, M A; Bauer, L L; Garleb, K A; Fahey, G C; de Godoy, M R C

    2016-05-01

    The objectives were to examine in vitro fermentation characteristics, in vivo nutrient digestibility, fecal microbiota, and serum lipid profiles as affected by α-cyclodextrin (ACD) supplementation. Short-chain fatty acid (SCFA) production was measured after in vitro fermentation for 3, 6, 9, and 12 h of ACD, β-cyclodextrin, and γ-cyclodextrin. Five mixed-breed hounds were used in a Latin square design. Each experimental period comprised 14 d, including 10 d for diet adaptation and 4 d for fecal collection. Dogs were fed, twice a day, an extruded diet made with poultry byproduct meal and brewer's rice as the main ingredients. Dogs were supplemented with 0, 1, 2, 3, or 4 g of ACD diluted in 15 mL of water twice daily for a total of 0, 2, 4, 6, and 8 g ACD/d. Maximal in vitro production of total SCFA was lowest for ACD. However, the greatest maximal production of propionate was noted for ACD treatment. Total tract nutrient digestibility and fecal DM concentration linearly decreased ( dogs and were not different among treatments. Similarly, no changes in fecal microbiota were observed. Overall, ACD supplementation appears to have no effect on nutrient absorption in the small intestine but may alter fermentation in the large bowel, which could lead to a higher proportion of propionate production as observed in the in vitro experiment.

  20. Hydroxypropyl cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimers as effective carbohydrate-solubilizers for polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Choi, Jae Min; Jeong, Daham; Piao, Jinglan; Kim, Kyoungtea; Nguyen, Andrew Bao Loc; Kwon, Nak-Jung; Lee, Mi-Kyung; Lee, Im Soon; Yu, Jae-Hyuk; Jung, Seunho

    2015-01-12

    The removal of polycyclic aromatic hydrocarbons by soil washing using water is extremely difficult due to their intrinsic hydrophobic nature. In this study, the effective aqueous solubility enhancements of seven polycyclic aromatic hydrocarbons by chemically modified hydroxypropyl rhizobial cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimer have been investigated for the first time. In the presence of hydroxypropyl cyclic β-(1 → 2)-D-glucans, the solubility of benzo[a]pyrene is increased up to 38 fold of its native solubility. The solubility of pyrene and phenanthrene dramatically increased up to 160 and 359. Coronene, chrysene, perylene, and fluoranthene also show an increase of 11, 23, 23, and 97 fold, respectively, of enhanced solubility by complexation with synthetic epichlorohydrin β-cyclodextrin dimer. The physicochemical properties of the complex are characterized by Fourier-transform infrared spectra and differential scanning calorimetry. Utilizing a scanning electron microscopy, the morphological structures of native benzo[a]pyrene, pyrene, phenanthrene, coronene, chrysene, perylene, fluoranthene and their complex with novel carbohydrate-solubilizers are studied. These results elucidate that polycyclic aromatic hydrocarbons are able to form an efficient complex with hydroxypropyl cyclic β-(1 → 2)-D-glucans and β-cyclodextrin dimer, suggesting the potential usage of chemically modified novel carbohydrate-solubilizers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Fast dissolving cyclodextrin complex of piroxicam in solid dispersion part I: influence of β-CD and HPβ-CD on the dissolution rate of piroxicam.

    Science.gov (United States)

    Bouchal, F; Skiba, M; Chaffai, N; Hallouard, F; Fatmi, S; Lahiani-Skiba, M

    2015-01-30

    Sublingual drug delivery is an interesting route for drug having significant hepatic first-pass metabolism or requiring rapid pharmacological effect as for patients suffering from swallowing difficulties, nausea or vomiting. Sublingual absorption could however be limited by the kinetic of drug dissolution. This study evaluated influences of cyclodextrins (β-CD or HP-β-CD) and their different inclusion process (spray-drying or freeze-drying) on the drug dissolution kinetic of solid dispersions in poly(ethylene glycol) (PEG, Mw 6000Da) of piroxicam, used as poor hydrosoluble drug model. A secondary objective was to determine influences of drug dispersion process in PEG (evaporation or melting methods) on the drug dissolution kinetic of piroxicam. Piroxicam solid dispersions containing or not cyclodextrins were characterized by different scanning calorimetry (DSC), Thermogravometry analyser (TGA) and Fourier transform-infrared spectroscopy (FT-IR) spectroscopy. In vitro drug dissolution study of these solid dispersions was then performed. The results demonstrated the high potential and interest of solid dispersions of drug previously included in cyclodextrins for sublingual delivery of hydrophobic drugs. This study also showed the advantages of evaporation method on the melting ones during drug dispersion in PEG. Indeed, drug complexation with cyclodextrins as dispersion by melting prevented the presence in solid dispersions of drug in crystalline form which can represent up to 63%. Moreover, dispersion in PEG by evaporation method gave more porous drug delivery system than with melting methods. This allowed complete (limited at most at 80-90% with melting methods) and quick drug dissolution without rebound effect like with melting ones. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. The effect of (2-hydroxypropyl)-beta-cyclodextrin on rheology of hydrophobically end-capped poly(ethylene glycol) aqueous solutions

    Czech Academy of Sciences Publication Activity Database

    Horský, Jiří; Mikešová, Jana; Quadrat, Otakar; Šňupárek, J.

    2004-01-01

    Roč. 48, č. 1 (2004), s. 23-38 ISSN 0148-6055 R&D Projects: GA ČR GA104/99/0560 Institutional research plan: CEZ:AV0Z4050913 Keywords : (2-hydroxypropyl)-beta-cyclodextrin * hydrophobized PEG * rheology Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.525, year: 2004

  3. Crystal structure of an essential enzyme in seed starch degradation - barley limit dextrinase in complex with cyclodextrins

    DEFF Research Database (Denmark)

    Vester-Christensen, Malene Bech; Abou Hachem, Maher; Svensson, Birte

    2010-01-01

    LD in complex with the competitive inhibitors α-cyclodextrin (CD) and β-CD are solved and refined to 2.5 Å and 2.1 Å, respectively, and are the first structures of a limit dextrinase. HvLD belongs to glycoside hydrolase 13 family and is composed of four domains: an immunoglobulin-like N-terminal eight...

  4. pH-controlled quaternary ammonium herbicides capture/release by carboxymethyl-β-cyclodextrin functionalized magnetic adsorbents: Mechanisms and application

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chang; Wang, Peng [Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing 100193 (China); Shen, Zhigang [Zhong Nong Fa Seed Industry Group Co. Ltd, Beijing 600313 (China); Liu, Xueke; Zhou, Zhiqiang [Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing 100193 (China); Liu, Donghui, E-mail: liudh@cau.edu.cn [Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing 100193 (China)

    2015-12-11

    In our work, the pH-controlled magnetic solid phase extraction for the determination of paraquat and diquat was introduced firstly. Furthermore, to clarify the mechanism of carboxymethyl-β-cyclodextrin functionalized magnetic adsorbents, we studied the pH-responsive supramolecular interaction between carboxymethyl-β-cyclodextrin (CM-β-CD) and paraquat/diquat by ultraviolet–visible (UV–vis) spectroscopy and nuclear magnetic resonance (NMR) experiment, and the energy-minimized structures were also obtained. Then, the functional group CM-β-CD was modified on the surface of magnetic materials to synthesize the adsorbent. The Fourier transform infrared spectrum (FT-IR) results proved the successful modification of CM-β-CD. Thus, this absorbent was applied for the determination of paraquat and diquat in water. Under the optimal condition, limits of detection (LODs) of paraquat and diquat were 0.8 μg L{sup −1} and 0.9 μg L{sup −1}, relative standard deviations (RSD) and recoveries varied 0.7–4.6% and 86.5–106.6%, respectively. Good recoveries (70.2–100.0%) and low RSD (1.7–9.6%) were achieved in analyzing spiked water samples. Furthermore, with the capillary electrophoresis (CE) as the analyser, the whole analytical process did not need the attendance of organic solvents. - Highlights: • The carboxymethyl-β-cyclodextrin functionalized magnetic adsorbents were synthesized. • The adsorbents could capture or release quaternary ammonium herbicides by changing pH. • The adsorbents were applied in the analysis of real water samples. • There is no attendance of organic solvents in the whole analysis process.

  5. A Molecular docking study to predict enantioseparation of some chiral carboxylic acid derivatives by methyl-β-cyclodextrin

    Science.gov (United States)

    Nurhidayah, E. S.; Ivansyah, A. L.; Martoprawiro, M. A.; Zulfikar, M. A.

    2018-05-01

    A molecular docking study, using molecular mechanics calculations with Arguslab, was used to help predict the enantioseparation of some guest molecules of chiral carboxylic acid derivatives by heptakis-2,6-di-O-methyl-β-cyclodextrin (DIMEB) and heptakis-2,3,6-tri-O-methyl-β-cyclodextrin (TRIMEB) as host molecules. The small differences in the binding free energy values (ΔΔG) obtained from Arguslab did not indicate any significant enantioseparation. From the molecular docking simulation results, it is predicted that in the case of DIMEB as host molecule, R-enantiomer of Etodolac, Fenoprofen, Indoprofen, Ketorolac, and Naproxen will be eluted first than S-enantiomer; However, S-enantiomer of Carprofen, Flurbiprofen, Ketoprofen, Pirprofen, Proglumide, Sulindac, Surprofen, and Zaltoprofen will be eluted first than R-enantiomer by DIMEB as host molecule. When TRIMEB is used as a host molecule, R-enantiomer of Carprofen, Flurbiprofen, Indoprofen, Ketoprofen, Naproxen, Pirprofen, and Surprofen will be eluted first than S-enantiomer; However, S-enantiomer of Etodolac, Fenoprofen, Ketorolac, Proglumide, Sulindac and Zaltoprofen will be eluted first than R-enantiomer by TRIMEB as host molecule.

  6. Microencapsulation of caffeic acid phenethyl ester and caffeic acid phenethyl amide by inclusion in hydroxypropyl-β-cyclodextrin.

    Science.gov (United States)

    Garrido, E Manuela P J; Cerqueira, Ana S; Chavarria, Daniel; Silva, Tiago; Borges, Fernanda; Garrido, Jorge M P J

    2018-07-15

    Caffeic acid phenethyl ester (CAPE) is a bioactive polyphenolic compound obtained from propolis extract. Although it has a broad therapeutic potential, the bioavailability of CAPE is limited, due to reduced solubility and poor plasmatic stability. Efforts to reduce these pharmacokinetic drawbacks resulted in the synthesis of caffeic acid phenethyl amide (CAPA). Cyclodextrins have been proved as promising excipients for the formulation of active ingredients. Herein, we report the inclusion complexation behavior and binding ability of CAPE and CAPA with hydroxypropyl-β-cyclodextrin (HP-β-CD). The supramolecular interactions were examined through UV and FTIR spectroscopy, DSC, 1 H NMR and 2D ROESY. The CAPE/HP-β-CD and CAPA/HP-β-CD inclusion complexes stability constants were determined to be, respectively, 2911.6 and 584.6 M -1 in water and 2866.2 and 700.1 M -1 at physiological pH. The aqueous solubility increased notably, proving that HP-β-CD can be potentially useful to improve the biological, chemical and physical properties of CAPE and CAPA. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Enantioseparation of pheniramine enantiomers by high-speed countercurrent chromatography using β-cyclodextrin derivatives as a chiral selector.

    Science.gov (United States)

    Xu, Weifeng; Wang, Shichuan; Xie, Xiaojuan; Zhang, Panliang; Tang, Kewen

    2017-10-01

    The enantioselective separation of pheniramine was studied by a high-speed countercurrent chromatography method using β-cyclodextrin derivatives as a chiral selector. Several key variables, for instance, type of organic solvent and chiral selector, concentration of chiral selector, pH value of aqueous phase, and temperature on the enantioselectivity, were investigated systematically by liquid-liquid extraction experiments. Combining the results of extraction experiments and high-speed countercurrent chromatography, the most suitable conditions for separation of pheniramine enantiomers were obtained with the two-phase system that consisted of isobutyl acetate/aqueous phase, containing 0.02 mol/L carboxymethyl-β-cyclodextrin, pH 8.50 at 278.15 K. Under the optimal conditions, pheniramine enantiomer was successfully resolved after four cycles of high-speed countercurrent chromatography. By using high-performance liquid chromatography to analyze the fractions, the purities of both (+)-pheniramine and (-)-pheniramine were over 99% and the recovery of this method was up to 85-90%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Diffusion coefficients of the ternary system (2-hydroxypropyl-{beta}-cyclodextrin + caffeine + water) at T = 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Ana C.F. [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal)], E-mail: anacfrib@ci.uc.pt; Santos, Cecilia I.A.V. [Departamento de Quimica Fisica, Facultad de Farmacia, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)], E-mail: cecilia.alves@uah.es; Lobo, Victor M.M. [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal)], E-mail: vlobo@ci.uc.pt; Cabral, Ana M.T.D.P.V. [Faculty of Pharmacy, University of Coimbra, 3000-295 Coimbra (Portugal)], E-mail: acabral@ff.uc.pt; Veiga, Francisco J.B. [Faculty of Pharmacy, University of Coimbra, 3000-295 Coimbra (Portugal)], E-mail: fveiga@ci.uc.pt; Esteso, Miguel A. [Departamento de Quimica Fisica, Facultad de Farmacia, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)], E-mail: miguel.esteso@uah.es

    2009-12-15

    Ternary mutual diffusion coefficients measured by Taylor dispersion method (D{sub 11}, D{sub 22}, D{sub 12}, and D{sub 21}) are reported for aqueous solutions of 2-hydroxypropyl-{beta}-cyclodextrin (HP-{beta}-CD) + caffeine at T = 298.15 K at carrier concentrations from (0.000 to 0.010) mol . dm{sup -3}, for each solute, respectively. These diffusion coefficients have been measured having in mind a better understanding of the structure of these systems and thermodynamic behaviour of caffeine and 2-hydroxypropyl-{beta}-cyclodextrin in solution. For example, from these data it will be possible to estimate some parameters, such as the fraction of associated species HP-{beta}-CD (X{sub 1}) and caffeine (X{sub 2}) in this complex, the monomer and dimer fractions, X{sub 2}{sup M} and X{sub 2}{sup D}, respectively, and the limiting diffusion coefficients of the HP-{beta}-CD, D{sub HPBCD}{sup 0}, of the dimers caffeine entities, D{sub D}{sup 0}, and of those complexes (1:1), D{sub complex}{sup 0}.

  9. Synergetic dual recognition and separation of the fungicide carbendazim by using magnetic nanoparticles carrying a molecularly imprinted polymer and immobilized β-cyclodextrin

    International Nuclear Information System (INIS)

    Li, Shuhuai; Wu, Xuejin; Zhang, Qun; Li, Pingping

    2016-01-01

    The authors describe a nanomaterial for solid-phase extraction of carbendazim. Magnetic molecularly imprinted polymer nanoparticles (mag-MIP-NPs) were obtained by immobilizing the MIP and a thiolated β-cyclodextrin on the surface of magnetite (Fe_3O_4) nanoparticles coated with gold nanoparticles. Both the recognition sites of the MIP and the hydrophobic cavities in the β-cyclodextrin contribute to the specific molecular recognition and extraction of carbendazim. The mag-MIP-NPs have an apparent adsorption capacity of 190 mg⋅g"-"1. Spiked vegetables were analyzed by using this material for extraction of carbendazim prior to its determination by ultra performance liquid chromatography (UHPLC). Recoveries range from 90.5 % to 109 %, and the detection limit is 3.0 pg⋅mL"-"1. (author)

  10. Preparation, characterization and in vitro evaluation of a new nucleotide analogue prodrug cyclodextrin inclusion complexes.

    OpenAIRE

    Diab , Roudayna; Jordheim , Lars P; Degobert , Ghania; Peyrottes , Suzanne; Périgaud , Christian; Dumontet , Charles; Fessi , Hatem

    2009-01-01

    International audience; Bis(tbutyl-S-acyl-2-thioethyl)-cytidine monophosophate is a new cytotoxic mononucleotide prodrug which have been developed to reverse the cellular resistance to nucleoside analogues. Unfortunately, its in vivo utilisation was hampered by its poor water solubility, raising the need of a molecular vector capable to mask its physicochemical characteristics although without affecting its cytotoxic activity. Hydroxypropyl-beta-cyclodextrin was used to prepare the prodrug in...

  11. Complexation induced aggregation and deaggregation of acridine orange with sulfobutylether-β-cyclodextrin.

    Science.gov (United States)

    Sayed, Mhejabeen; Jha, Shruti; Pal, Haridas

    2017-09-13

    The present study reports a contrasting interaction behaviour of a biologically important dye, acridine orange (AOH + ), with a highly water soluble anionic host, based on a β-cyclodextrin (βCD) scaffold, i.e. sulfobutylether-β-cyclodextrin (SBEβCD), in comparison to native βCD. AOH + shows striking modulation in its photophysical properties, representing sequential changes in the modes of interaction with increasing SBEβCD concentration. At lower SBEβCD concentrations, AOH + preferentially binds in dimeric forms at the negatively charged SBEβCD portals, leading to strong fluorescence quenching. At higher SBEβCD concentrations, the dimeric dyes convert to monomeric forms and subsequently undergo both inclusion and exo complex formation with 1 : 1 stoichiometry, resulting in a large fluorescence enhancement. The intriguing observation of sequential fluorescence switch off and switch on for an AOH + -SBEβCD system is clearly facilitated by the presence of butylether chains with SO 3 - end groups at the portals of SBEβCD, providing an additional ion-ion interaction and much enhanced hydrophobic interaction for cationic AOH + compared to the native βCD host. To the best of our knowledge, such fluorescence off/on switching through multistep host-guest binding has not been reported so far in the literature. The present study not only provides a detailed insight into the unique binding interactions of AOH + with the SBEβCD host, but the findings of this study are also expected to be useful in designing supramolecular based drug formulations, drug delivery systems, sensors, and so on.

  12. Induction of mitophagy-mediated antitumor activity with folate-appended methyl-β-cyclodextrin.

    Science.gov (United States)

    Kameyama, Kazuhisa; Motoyama, Keiichi; Tanaka, Nao; Yamashita, Yuki; Higashi, Taishi; Arima, Hidetoshi

    2017-01-01

    Mitophagy is the specific autophagic elimination system of mitochondria, which regulates cellular survival via the removal of damaged mitochondria. Recently, we revealed that folate-appended methyl-β-cyclodextrin (FA-M-β-CyD) provides selective antitumor activity in folate receptor-α (FR-α)-expressing cells by the induction of autophagy. In this study, to gain insight into the detailed mechanism of this antitumor activity, we focused on the induction of mitophagy by the treatment of FR-α-expressing tumor cells with FA-M-β-CyD. In contrast to methyl-β-cyclodextrin, FA-M-β-CyD entered KB cells, human epithelial cells from a fatal cervical carcinoma (FR-α (+)) through FR-α-mediated endocytosis. The transmembrane potential of isolated mitochondria after treatment with FA-M-β-CyD was significantly elevated. In addition, FA-M-β-CyD lowered adenosine triphosphate (ATP) production and promoted reactive oxygen species production in KB cells (FR-α (+)). Importantly, FA-M-β-CyD enhanced light chain 3 (LC3) conversion (LC3-I to LC3-II) in KB cells (FR-α (+)) and induced PTEN-induced putative kinase 1 (PINK1) protein expression, which is involved in the induction of mitophagy. Furthermore, FA-M-β-CyD had potent antitumor activity in BALB/c nu/nu mice xenografted with KB cells (FR-α (+)) without any significant side effects. Taken together, these findings demonstrate that the autophagic cell death elicited by FA-M-β-CyD could be associated with mitophagy induced by an impaired mitochondrial function.

  13. Investigation of Cyclodextrin-Based Nanosponges for Solubility and Bioavailability Enhancement of Rilpivirine.

    Science.gov (United States)

    Rao, Monica R P; Chaudhari, Jagruti; Trotta, Francesco; Caldera, Fabrizio

    2018-06-04

    Rilpivrine is BCS class II drug used for treatment of HIV infection. The drug has low aqueous solubility (0.0166 mg/ml) and dissolution rate leading to low bioavailability (32%). Aim of this work was to enhance solubility and dissolution of rilpivirine using beta-cyclodextrin-based nanosponges. These nanosponges are biocompatible nanoporous particles having high loading capacity to form supramolecular inclusion and non-inclusion complexes with hydrophilic and lipophilic drugs for solubility enhancement. Beta-cyclodextrin was crosslinked with carbonyl diimidazole and pyromellitic dianhydride to prepare nanosponges. The nanosponges were loaded with rilpivirine by solvent evaporation method. Binary and ternary complexes of drug with β-CD, HP-β-CD, nanosponges, and tocopherol polyethylene glycol succinate were prepared and characterized by phase solubility, saturation solubility in different media, in vitro dissolution, and in vivo pharmacokinetics. Spectral analysis by Fourier transform infrared spectroscopy, powder X-ray diffraction, and differential scanning calorimetry was performed. Results obtained from spectral characterization confirmed inclusion complexation. Phase solubility studies indicated stable complex formation. Saturation solubility was found to be 10-13-folds higher with ternary complexes in distilled water and 12-14-fold higher in 0.1 N HCl. Solubility enhancement was evident in biorelevant media. Molecular modeling studies revealed possible mode of entrapment of rilpivirine within β-CD cavities. A 3-fold increase in dissolution with ternary complexes was observed. Animal studies revealed nearly 2-fold increase in oral bioavailability of rilpivirine. It was inferred that electronic interactions, hydrogen bonding, and van der Waals forces are involved in the supramolecular interactions.

  14. Statistically designed enzymatic hydrolysis of an icariin/β-cyclodextrin inclusion complex optimized for production of icaritin

    Directory of Open Access Journals (Sweden)

    Xin Jin

    2012-02-01

    Full Text Available This study focuses on the preparation and enzymic hydrolysis of an icariin/β-cyclodextrin inclusion complex to efficiently generate icaritin. The physical characteristics of the inclusion complex were evaluated by differential scanning calorimetry (DSC. Enzymatic hydrolysis was optimized for the conversion of icariin/β-cyclodextrin complex to icaritin by Box–Behnken statistical design. The inclusion complex formulation increased the solubility of icariin approximately 17-fold, from 29.2 to 513.5 μg/mL at 60 °C. The optimum conditions were predicted by Box–Behnken statistical design as follows: 60 °C, pH 7.0, the ratio of enzyme/substrate (1:1.1 and reaction time 7 h. Under the optimal conditions the conversion of icariin was 97.91% and the reaction time was decreased by 68% compared with that without β-CD inclusion. Product analysis by melting point, ESI-MS, UV, IR, 1H NMR and 13C NMR confirmed the authenticity of icaritin with a purity of 99.3% and a yield of 473 mg of icaritin from 1.1 g icariin.

  15. Cyclodextrin-enhanced biodegradation of phenanthrene

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.-M.; Marlowe, E.M.; Miller-Maier, R.M.; Brusseau, M.L. [University of Arizona, Tuscon, AZ (United States). Dept. of Soil, Water and Environmental Science

    1998-07-01

    The effectiveness of in situ bioremediation in many systems may be constrained by low contaminant bioavailability due to limited aqueous solubility or a large magnitude of sorption. The objective of this research was to evaluate the effect of hydroxypropyl-{beta}-cyclodextrin (HPCD) on phenanthrene solubilization and biodegradation. Results showed that analytical-grade HPCD can significantly increase the apparent solubility of phenanthrene. The increase in apparent solubility had a major impact on the biodegradation rate of phenanthrene. For example, in the presence of 10{sup 5} mg L{sup -1} HPCD, the substrate utilization rate increased from 0.17 mg h{sup -1} to 0.93 mg h{sup -1} while the apparent solubility was increased from 1.3 mg L{sup -1} to 161.3 mg L{sup -1}. As a result, only 0.3% of the phenanthrene remained at the end of a 48 h incubation for the highest concentration of HPCD tested (10{sup 5} mg L{sup -1}). In contrast, 45.2% of the phenanthrene remained in the absence of HPCD. Technical-grade HPCD, which contains the biodegradable impurity propylene glycol, also increased the substrate utilization rate, although to a lesser extent than the analytical-grade HPCD. On the basis of these results, it appears that HPCD can significantly increase the bioavailability, and thereby enhance the biodegradation of phenanthrene. 26 refs., 5 figs.

  16. Application of cyclodextrins in textile processes;Aplicacao de ciclodextrinas em processos texteis

    Energy Technology Data Exchange (ETDEWEB)

    Andreaus, Juergen; Dalmolin, Mara C.; Oliveira Junior, Iguatemy B. de; Barcellos, Ivonete O., E-mail: jandr@furb.b [Universidade Regional de Blumenau, SC (Brazil). Dept. de Quimica

    2010-07-01

    Cyclodextrins (CDs) are water soluble cyclic sugars with a hydrophobic nanometric cavity that permits the formation of host/guest inclusion complexes with a large variety of molecules, alternating their physical-chemical properties. In the present review CD research related to the processing of textiles is revised and discussed. CDs may function as encapsulating, dispersing and levelling agents in the dyeing and washing of textiles. Furthermore they may be anchored to polymers and textile fibers in order to impart special properties such as odor reduction, UV protection or for the controlled release of perfumes, aromas, mosquito repellents or substances with therapeutical effects. (author)

  17. Thermodynamics of inclusion complex formation of β-cyclodextrin with a variety of surfactants differing in the nature of headgroup

    International Nuclear Information System (INIS)

    Benkő, Mária; Király, Zoltán

    2012-01-01

    Highlights: ► Inclusion complexation of β-cyclodextrins with various surfactants. ► Thermodynamic parameters determined by titration microcalorimetry. ► Stoichiometry of complexation is 1:1. ► The binding constant decreases linearly with increasing temperature. ► Enthalpy–entropy compensation is independent of the nature of the headgroup. - Abstract: The inclusion complexation of β-cyclodextrin with various surfactants, possessing the same alkyl chain length but differing in the hydrophilic headgroup, was investigated by isothermal titration microcalorimetry. Sodium dodecyl sulfate, sodium dodecyl sulfonate, dodecyltrimethylammonium bromide and dodecyl(dimethyl)amine oxide were investigated. The major aim of this study was to elucidate the effects of temperature and the nature of the headgroup on the complex formation. Thermometric titrations were effected between the temperatures (288 and 348) K. The results provided the stoichiometry, the equilibrium constant and the reaction enthalpy of complexation. Changes in Gibbs energy, entropy and van’t Hoff enthalpy were additionally calculated.

  18. Synthesis of amorphous calcium phosphate using various types of cyclodextrins

    International Nuclear Information System (INIS)

    Li Yanbao; Wiliana, Tjandra; Tam, Kam C.

    2007-01-01

    Amorphous calcium phosphate (ACP) was synthesised in aqueous solution at room temperature using cyclodextrins. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and thermal analysis (DTA/TGA) were performed on the calcium phosphate precipitates obtained from solutions. We observed that only β-CD could stabilise the amorphous phase in the mother solution because of the lower solubility of β-CD in water and the ACP remained stable in aqueous solution for more than 24 h at room temperature. The ACP particle has an initial particle size of less than 40 nm, Ca/P molar ratio of 1.67 and β-CD absorbed on its surface. The mechanism for the stabilisation of ACP is proposed

  19. Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

    OpenAIRE

    Rizzi, Vito; Matera, Sergio; Semeraro, Paola; Fini, Paola; Cosma, Pinalysa

    2016-01-01

    Since several years the inclusion of organic compounds (guests) within the hydrophobic cavity (host) of cyclodextrins (CDs) has been the subject of many investigations. Interestingly, the formation of inclusion complexes could affect the properties of the guest molecules and, for example, the influence of the delivery system can be a method to improve/change the photochemical behavior of the guest. In particular, very recent studies have shown the protective role of CDs preventing the degrada...

  20. Enhanced host–guest electrochemical recognition of herbicide MCPA using a b-cyclodextrin carbon nanotube sensor

    OpenAIRE

    Rahemi, V.; Vandamme, J.J.; Garrido, J.M.P.J.; Borges, F.; Brett, C.M.A.; Garrido, E.M.P.J.

    2012-01-01

    An electrochemical sensor for the determination of the chlorophenoxy herbicide MCPA has been developed, based on a combination of multi-walled carbon nanotubes with incorporated b-cyclodextrin and a polyaniline film modified glassy carbon electrode. The proposed molecular host–guest recogni-tion based sensor has a high electrochemical sensitivity for the determination of MCPA. The electrochemical behaviour of MCPA at the chemically modified electrode was investigated in detail by cyclic volta...

  1. A novel oral delivery system consisting in "drug-in cyclodextrin-in nanostructured lipid carriers" for poorly water-soluble drug: vinpocetine.

    Science.gov (United States)

    Lin, Congcong; Chen, Fen; Ye, Tiantian; Zhang, Lina; Zhang, Wenji; Liu, Dandan; Xiong, Wei; Yang, Xinggang; Pan, Weisan

    2014-04-25

    The purpose of this study was to develop a new delivery system based on drug cyclodextrin (CD) complexation and loading into nanostructured lipid carriers (NLC) to improve the oral bioavailability of vinpocetine (VP). Three different CDs and three different methods to obtain solid vinpocetine-cyclodextrin-tartaric acid complexes (VP-CD-TA) were contrasted. The co-evaporation vinpocetine-β-cyclodextrin-tartaric acid loaded NLC (VP-β-CD-TA COE-loaded NLC) was obtained by emulsification ultrasonic dispersion method. VP-β-CD-TA COE-loaded NLC was suitably characterized for particle size, polydispersity index, zeta potential, entrapment efficiency and the morphology. The crystallization of drug in VP-CD-TA and NLC was investigated by differential scanning calorimetry (DSC). The in vitro release study was carried out at pH 1.2, pH 6.8 and pH 7.4 medium. New Zealand rabbits were applied to investigate the pharmacokinetic behavior in vivo. The VP-β-CD-TA COE-loaded NLC presented a superior physicochemical property and selected to further study. In the in vitro release study, VP-β-CD-TA COE-loaded NLC exhibited a higher dissolution rate in the pH 6.8 and pH 7.4 medium than VP suspension and VP-NLC. The relative bioavailability of VP-β-CD-TA COE-loaded NLC was 592% compared with VP suspension and 92% higher than VP-NLC. In conclusion, the new formulation significantly improved bioavailability of VP for oral delivery, demonstrated a perspective way for oral delivery of poorly water-soluble drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Detailed NMR investigation of cyclodextrin-perfluorinated surfactant interactions in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Weiss-Errico, Mary Jo; O’Shea, Kevin E., E-mail: osheak@fiu.edu

    2017-05-05

    Highlights: • Perfluorochemicals (PFCs) are strongly encapsulated by cyclodextrins (CDs). • Competition studies confirm strong CD:PFC host-guest interactions. • {sup 19}F NMR Spectroscopy demonstrates association constants up to 10{sup 5} M{sup −1}. • Position of CD along PFC chain is elucidated from NMR results. • CD:PFC complex is not disturbed under a variety of water quality conditions. - Abstract: Perfluorochemicals (PFCs) are contaminants of serious concern because of their toxicological properties, widespread presence in drinking water sources, and incredible stability in the environment. To assess the potential application of α-, β-, and γ-cyclodextrins for PFC remediation, we investigated their complexation with linear fluorinated carboxylic acids, sulfonates, and a sulfonamide with carbon backbones ranging from C4-C9. {sup 19}F Nuclear Magnetic Resonance (NMR) spectroscopy studies demonstrated β-CD formed the strongest complexes with these PFCs. The polar head group had a modest influence, but for PFCs with backbones longer than six carbons, strong association constants are observed for 1:1 (K{sub 1:1} ∼ 10{sup 5} M{sup −1}) and 2:1 (K{sub 2:1} ∼ 10{sup 3} M{sup −1}) β-CD:PFC complexes. Excess β-CD can be used to complex 99.5% of the longer chain PFCs. Competition studies with adamantane-carboxylic acid and phenol confirmed the nature and persistence of the β-CD:PFC complex. Detailed analyses of the individual NMR chemical shifts and Job plots indicate the favored positions of the β-CD along the PFC chain. Solution pH, ionic strength, and the presence of humic acid have modest influence on the β-CD:PFC complexes. The strong encapsulation of PFCs by β-CD under a variety of water quality conditions demonstrates the tremendous potential of CD-based materials for the environmental remediation of PFCs.

  3. Enantiopurity analysis of new types of acyclic nucleoside phosphonates by capillary electrophoresis with cyclodextrins as chiral selectors

    Czech Academy of Sciences Publication Activity Database

    Šolínová, Veronika; Kaiser, Martin Maxmilian; Lukáč, Miloš; Janeba, Zlatko; Kašička, Václav

    2014-01-01

    Roč. 37, č. 3 (2014), s. 295-303 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * CE * chiral analysis * cyclodextrins * nucleotide analogs Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.737, year: 2014

  4. Investigation into reactions of starch with monochloro triazinyl- {beta} Cyclodextrin and Application of their Products in Textile Sizing

    Energy Technology Data Exchange (ETDEWEB)

    Hebeish, A; Higazy, A; El- Shafei, A; Sharaf, S [National Research Center, Textile Research Division, Dokki, Cairo (Egypt)

    2005-07-01

    Chemical modification of starch and hydrolyzed starches through their reaction with reactive cyclodextrin (RCD), namely, monochloro triazinyl-B cyclodextrin was investigated under a variety of conditions. Results obtained signify that the reaction is favoured in alkaline rather than in acidic media and in shorter than larger liquor ratios. Maximization of the reaction could also be achieved at 40 degree C for 60 minutes. Of the several alkaline catalysts used NaOH proved to be the best when used at a concentration of 10 g/1. Reaction of starch and hydrolyzed starches with RCD is determined by concentration of the latter. It brings about polymeric products the apparent viscosity of which depends on both the extent of reaction, expressed as nitrogen percent, and degree of acid hydrolysis prior to the modification. Evidence for involvement of starch and RCD by chemical bonding is evidenced by FTIR analysis. Furthermore the newly synthesized starch based polymeric products were applied to light cotton fabric and evaluation of the sized materials through monitoring size add-on, size removal and strength properties of the fabric made.

  5. Investigation into reactions of starch with monochloro triazinyl- Β Cyclodextrin and Application of their Products in Textile Sizing

    International Nuclear Information System (INIS)

    Hebeish, A.; Higazy, A.; El- Shafei, A.; Sharaf, S.

    2005-01-01

    Chemical modification of starch and hydrolyzed starches through their reaction with reactive cyclodextrin (RCD), namely, monochloro triazinyl-B cyclodextrin was investigated under a variety of conditions. Results obtained signify that the reaction is favoured in alkaline rather than in acidic media and in shorter than larger liquor ratios. Maximization of the reaction could also be achieved at 40 degree C for 60 minutes. Of the several alkaline catalysts used NaOH proved to be the best when used at a concentration of 10 g/1. Reaction of starch and hydrolyzed starches with RCD is determined by concentration of the latter. It brings about polymeric products the apparent viscosity of which depends on both the extent of reaction, expressed as nitrogen percent, and degree of acid hydrolysis prior to the modification. Evidence for involvement of starch and RCD by chemical bonding is evidenced by FTIR analysis. Furthermore the newly synthesized starch based polymeric products were applied to light cotton fabric and evaluation of the sized materials through monitoring size add-on, size removal and strength properties of the fabric made

  6. Silver nanoparticle colloids with γ-cyclodextrin: enhanced stability and Gibbs–Marangoni flow

    Energy Technology Data Exchange (ETDEWEB)

    Amiri, Setareh; Duroux, Laurent; Larsen, Kim Lambertsen, E-mail: kll@bio.aau.dk [Aalborg University, Department of Chemistry and Bioscience (Denmark)

    2015-01-15

    Although cyclodextrins (CD) are effective stabilizers for metal nanoparticle colloids, differences between α-, β- and γ-CD in stabilizing such colloids have not been previously reported. In this study, silver nanoparticles (AgNP) were synthesized using NaBH{sub 4} as reducing agent and cyclodextrins as stabilizers. Long-term stability of AgNP colloids in equilibrium conditions showed no marked differences between CD types. Transmission electron microscopy and quantitative image analysis revealed only marginal differences in particle sizes for CD-AgNP, although statistically significant. CD-AgNP colloids showed dispersed particles with average diameters of 7.3 ± 2.2, 6.3 ± 2.9 and 4.9 ± 1.9 nm for α-, β- and γ-CD, respectively, and with similar ζ-potentials about −25 to −30 mV. AgNP without CD showed bigger and aggregated particles of 15.0 ± 2.0 nm with lower ζ-potentials of about −40 mV. When subjected to centrifugal forces, i.e. non-equilibrium conditions, γ-CD was markedly more efficient than α- and β-CD in stabilizing the colloids. Drying patterns of colloid droplets showed a typical self-pinned coffee ring for all but the colloid stabilized by γ-CD, which showed a pattern resulting from a dominant Gibbs–Marangoni flow inside the drying droplet. Calculations using the Derjaguin, Landau, Verwey and Overbeek (DLVO) theory supported the stabilizing effect of CD in equilibrium conditions; it however did not provide clues for the superior stabilization by γ-CD in conditions of hydrodynamic stress.

  7. Silver nanoparticle colloids with γ-cyclodextrin: enhanced stability and Gibbs–Marangoni flow

    International Nuclear Information System (INIS)

    Amiri, Setareh; Duroux, Laurent; Larsen, Kim Lambertsen

    2015-01-01

    Although cyclodextrins (CD) are effective stabilizers for metal nanoparticle colloids, differences between α-, β- and γ-CD in stabilizing such colloids have not been previously reported. In this study, silver nanoparticles (AgNP) were synthesized using NaBH 4 as reducing agent and cyclodextrins as stabilizers. Long-term stability of AgNP colloids in equilibrium conditions showed no marked differences between CD types. Transmission electron microscopy and quantitative image analysis revealed only marginal differences in particle sizes for CD-AgNP, although statistically significant. CD-AgNP colloids showed dispersed particles with average diameters of 7.3 ± 2.2, 6.3 ± 2.9 and 4.9 ± 1.9 nm for α-, β- and γ-CD, respectively, and with similar ζ-potentials about −25 to −30 mV. AgNP without CD showed bigger and aggregated particles of 15.0 ± 2.0 nm with lower ζ-potentials of about −40 mV. When subjected to centrifugal forces, i.e. non-equilibrium conditions, γ-CD was markedly more efficient than α- and β-CD in stabilizing the colloids. Drying patterns of colloid droplets showed a typical self-pinned coffee ring for all but the colloid stabilized by γ-CD, which showed a pattern resulting from a dominant Gibbs–Marangoni flow inside the drying droplet. Calculations using the Derjaguin, Landau, Verwey and Overbeek (DLVO) theory supported the stabilizing effect of CD in equilibrium conditions; it however did not provide clues for the superior stabilization by γ-CD in conditions of hydrodynamic stress

  8. Redox potentials and binding enhancement of fullerene and fullerene-cyclodextrin systems in water and dimethylsulfoxide

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Lubomír; Hromadová, Magdaléna; Gál, Miroslav; Kocábová, Jana; Sokolová, Romana; Filippone, S.; Yang, J.; Guan, Z.; Rassat, A.; Zhang, Y.

    2010-01-01

    Roč. 48, č. 1 (2010), s. 153-162 ISSN 0008-6223 R&D Projects: GA ČR GA203/09/0705; GA ČR GA203/08/1157; GA ČR GP203/09/P502; GA MŠk LC510; GA MŠk ME09114; GA MŠk OC 140 Institutional research plan: CEZ:AV0Z40400503 Keywords : electrochemistry * fullerene s * fullerene -cyclodextrin systems Subject RIV: CG - Electrochemistry Impact factor: 4.893, year: 2010

  9. Fe-Ni Nanoparticles supported on carbon nanotube-co-cyclodextrin polyurethanes for the removal of trichloroethylene in water

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Rui W. M., E-mail: rkrause@uj.ac.za; Mamba, Bhekie B.; Dlamini, Langelihle N.; Durbach, Shane H. [University of Johannesburg, Department of Chemical Technology (South Africa)

    2010-02-15

    Nanoscale bimetallic particles of nickel on iron were supported on carbon nanotubes and then co-polymerized with {beta}-cyclodextrin (CNTs/CD) and the resulting polymers applied to the degradation of pollutants in water. The bimetallic nanoparticles (BMNPs) were first embedded on functionalized carbon nanotubes (f-CNTs) before being copolymerized with beta cyclodextrin ({beta}-CD) and hexamethylene diisocyanate (HMDI) forming a water-insoluble polyurethane. The particle size and distribution of BMNPs were determined by Transmission Electron Microscopy (TEM), and the surface area was determined by using the Brunauer-Emmett-Teller (BET) method. Energy dispersive X-ray spectroscopy (EDXS) was used to confirm the formation of the BMNPs. Degradation of trichloroethylene (TCE) as a model pollutant was studied and more than 98% reduction in TCE was achieved by the polymers. Polymers with the BMNPs maintained their efficiency in degrading TCE after several cycles compared to metal-free polymers. The degradation was monitored by using gas chromatography-mass spectrometry (GC-MS), while the production of chlorides was verified by using ion chromatography (IC). Atomic absorption spectroscopy (AAS) was employed to determine the possible leaching of the BMNPs from the polymer, and confirmed to be extremely low.

  10. Fe-Ni Nanoparticles supported on carbon nanotube-co-cyclodextrin polyurethanes for the removal of trichloroethylene in water

    International Nuclear Information System (INIS)

    Krause, Rui W. M.; Mamba, Bhekie B.; Dlamini, Langelihle N.; Durbach, Shane H.

    2010-01-01

    Nanoscale bimetallic particles of nickel on iron were supported on carbon nanotubes and then co-polymerized with β-cyclodextrin (CNTs/CD) and the resulting polymers applied to the degradation of pollutants in water. The bimetallic nanoparticles (BMNPs) were first embedded on functionalized carbon nanotubes (f-CNTs) before being copolymerized with beta cyclodextrin (β-CD) and hexamethylene diisocyanate (HMDI) forming a water-insoluble polyurethane. The particle size and distribution of BMNPs were determined by Transmission Electron Microscopy (TEM), and the surface area was determined by using the Brunauer-Emmett-Teller (BET) method. Energy dispersive X-ray spectroscopy (EDXS) was used to confirm the formation of the BMNPs. Degradation of trichloroethylene (TCE) as a model pollutant was studied and more than 98% reduction in TCE was achieved by the polymers. Polymers with the BMNPs maintained their efficiency in degrading TCE after several cycles compared to metal-free polymers. The degradation was monitored by using gas chromatography-mass spectrometry (GC-MS), while the production of chlorides was verified by using ion chromatography (IC). Atomic absorption spectroscopy (AAS) was employed to determine the possible leaching of the BMNPs from the polymer, and confirmed to be extremely low.

  11. Release of β-galactosidase from poloxamine/α-cyclodextrin hydrogels

    Directory of Open Access Journals (Sweden)

    César A. Estévez

    2014-12-01

    Full Text Available All mammals lose their ability to produce lactase (β-galactosidase, the enzyme that cleaves lactose into galactose and glucose, after weaning. The prevalence of lactase deficiency (LD spans from 2 to 15% among northern Europeans, to nearly 100% among Asians. Following lactose consumption, people with LD often experience gastrointestinal symptoms such as abdominal pain, bowel distension, cramps and flatulence, or even systemic problems such as headache, loss of concentration and muscle pain. These symptoms vary depending on the amount of lactose ingested, type of food and degree of intolerance. Although those affected can avoid the uptake of dairy products, in doing so, they lose a readily available source of calcium and protein. In this work, gels obtained by complexation of Tetronic 90R4 with α-cyclodextrin loaded with β-galactosidase are proposed as a way to administer the enzyme immediately before or with the lactose-containing meal. Both molecules are biocompatible, can form gels in situ, and show sustained erosion kinetics in aqueous media. The complex was characterized by FTIR that evidenced an inclusion complex between the polyethylene oxide block and α-cyclodextrin. The release profiles of β-galactosidase from two different matrices (gels and tablets of the in situ hydrogels have been obtained. The influence of the percentage of Tetronic in media of different pH was evaluated. No differences were observed regarding the release rate from the gel matrices at pH 6 (t50 = 105 min. However, in the case of the tablets, the kinetics were faster and they released a greater amount of 90R4 (25%, t50 = 40–50 min. Also, the amount of enzyme released was higher for mixtures with 25% Tetronic. Using suitable mathematical models, the corresponding kinetic parameters have been calculated. In all cases, the release data fit quite well to the Peppas–Sahlin model equation, indicating that the release of β-galactosidase is governed by a

  12. Properties of cationic monosubstituted tetraalkylammonium cyclodextrin derivatives – their stability, complexation ability in solution or when deposited on solid anionic surface

    Czech Academy of Sciences Publication Activity Database

    Popr, M.; Filippov, Sergey K.; Matushkin, Nikolai; Dian, J.; Jindřich, J.

    2015-01-01

    Roč. 11, February (2015), s. 192-199 ISSN 1860-5397 R&D Projects: GA ČR GAP108/12/0640 Institutional support: RVO:61389013 Keywords : cyclodextrins * inclusion properties * solid surface Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.697, year: 2015

  13. Exploration of inclusion complexes of neurotransmitters with β-cyclodextrin by physicochemical techniques

    Science.gov (United States)

    Roy, Mahendra Nath; Saha, Subhadeep; Kundu, Mitali; Saha, Binoy Chandra; Barman, Siti

    2016-07-01

    Molecular assemblies of β-cyclodextrin with few of the most important neurotransmitters, viz., dopamine hydrochloride, tyramine hydrochloride and (±)-epinephrine hydrochloride in aqueous medium have been explored by reliable spectroscopic and physicochemical techniques as potential drug delivery systems. Job plots confirm the 1:1 host-guest inclusion complexes, while surface tension and conductivity studies illustrate the inclusion process. The inclusion complexes were characterized by 1H NMR spectroscopy and association constants have been calculated by using Benesi-Hildebrand method. Thermodynamic parameters for the formation of inclusion complexes have been derived by van't Hoff equation, which demonstrate that the overall inclusion processes are thermodynamically favorable.

  14. Construction and Characterization of a Chitosan-Immobilized-Enzyme and β-Cyclodextrin-Included-Ferrocene-Based Electrochemical Biosensor for H2O2 Detection

    Directory of Open Access Journals (Sweden)

    Wenbo Dong

    2017-07-01

    Full Text Available An electrochemical detection biosensor was prepared with the chitosan-immobilized-enzyme (CTS-CAT and β-cyclodextrin-included-ferrocene (β-CD-FE complex for the determination of H2O2. Ferrocene (FE was included in β-cyclodextrin (β-CD to increase its stability. The structure of the β-CD-FE was characterized. The inclusion amount, inclusion rate, and electrochemical properties of inclusion complexes were determined to optimize the reaction conditions for the inclusion. CTS-CAT was prepared by a step-by-step immobilization method, which overcame the disadvantages of the conventional preparation methods. The immobilization conditions were optimized to obtain the desired enzyme activity. CTS-CAT/β-CD-FE composite electrodes were prepared by compositing the CTS-CAT with the β-CD-FE complex on a glassy carbon electrode and used for the electrochemical detection of H2O2. It was found that the CTS-CAT could produce a strong reduction peak current in response to H2O2 and the β-CD-FE could amplify the current signal. The peak current exhibited a linear relationship with the H2O2 concentration in the range of 1.0 × 10−7–6.0 × 10−3 mol/L. Our work provided a novel method for the construction of electrochemical biosensors with a fast response, good stability, high sensitivity, and a wide linear response range based on the composite of chitosan and cyclodextrin.

  15. Inclusion complex of tamibarotene with hydroxypropyl-β-cyclodextrin: Preparation, characterization, in-vitro and in-vivo evaluation

    Directory of Open Access Journals (Sweden)

    Ying Yang

    2017-03-01

    Full Text Available The goal of this study was to improve the solubility and oral bioavailability of tamibarotene by complexing it with hydroxypropyl-β-cyclodextrin (HP-β-CD. The inclusion complex of tamibarotene with hydroxypropyl-β-cyclodextrin (Am80-HP-β-CD was prepared through a freeze-drying method at the mole ratio of 1:1 (Am80: HP-β-CD. Fourier transform infrared spectroscopy (FT-IR and differential scanning calorimetry (DSC indicated the formation of Am80-HP-β-CD. In vitro dissolution studies showed that the solubility and dissolution percentage of Am80-HP-β-CD was improved substantially compared to Am80. An improved dissolution with approximately 97% drug release in 3 min was observed, in comparison with Am80 with approximately 60% release in 45 min. In vivo studies indicated that the AUC0-∞ has increased 2.79 times and the Cmax 4.37 times after the formation of inclusion complex. The decrease of tmax indicated the Am80-HP-β-CD inclusion complex can be absorbed into blood faster. In short, the solubility and bio-availability of Am80 has notably increased with the complexation of HP-β-CD. Therefore, using the inclusion technique is a promising method to improve the solubility of insoluble drugs.

  16. Evaluation of γ-cyclodextrin effect on permeation of lipophilic drugs: application of cellophane/fused octanol membrane.

    Science.gov (United States)

    Muankaew, Chutimon; Jansook, Phatsawee; Loftsson, Thorsteinn

    2017-06-01

    According to the Biopharmaceutics Classification System, oral bioavailability of drugs is determined by their aqueous solubility and the ability of the dissolved drug molecules to permeate lipophilic biological membranes. Similarly topical bioavailability of ophthalmic drugs is determined by their solubility in the aqueous tear fluid and their ability to permeate the lipophilic cornea. Enabling pharmaceutical excipients such as cyclodextrins can have profound effect on the drug bioavailability. However, to fully appreciate such enabling excipients, the relationship between their effects and the physicochemical properties of the permeating drug needs to be known. In this study, the permeation enhancing effect of γ-cyclodextrin (γCD) on saturated drug solutions containing hydrocortisone (HC), irbesartan (IBS), or telmisartan (TEL) was evaluated using cellophane and fused cellulose-octanol membranes in a conventional Franz diffusion cell system. The flux (J), the flux ratio (J R ) and the apparent permeability coefficients (P app ) demonstrate that γCD increases drug permeability. However, its efficacy depends on the drug properties. Addition of γCD increased P app of HC (unionized) and IBS (partially ionized) through the dual membrane but decreased the P app of TEL (fully ionized) that displays low complexation efficacy. The dual cellophane-octanol membrane system was simple to use and gave reproducible results.

  17. Cyclodextrins: A Weapon in the Fight Against Antimicrobial Resistance

    Science.gov (United States)

    Wong, Chew Ee; Dolzhenko, Anton V.; Lee, Sui Mae; Young, David James

    Antimicrobial resistance poses one of the most serious global challenges of our age. Cyclodextrins (CDs) are widely utilized excipients in formulations because of their solubilizing properties, low toxicity, and low inflammatory response. This review summarizes recent investigations of antimicrobial agents involving CDs and CD-based antimicrobial materials. CDs have been employed for antimicrobial applications either through formation of inclusion complexes or by chemical modification of their hydroxyl groups to tailor pharmaceutically active compounds. Applications of these CD inclusion complexes include drug delivery, antimicrobial coatings on materials (e.g., biomedical devices and implants) and antimicrobial dressings that help to prevent wound infections. There are relatively limited studies of chemically modified CDs with antimicrobial activity. The mechanism of action of antimicrobial CD inclusion complexes and derivatives needs further elucidation, but activity of CDs and their derivatives is often associated with their interaction with bacterial cell membranes.

  18. Synthesis of Randomly Substituted Anionic Cyclodextrins in Ball Milling

    Directory of Open Access Journals (Sweden)

    László Jicsinszky

    2017-03-01

    Full Text Available A number of influencing factors mean that the random substitution of cyclodextrins (CD in solution is difficult to reproduce. Reaction assembly in mechanochemistry reduces the number of these factors. However, lack of water can improve the reaction outcomes by minimizing the reagent’s hydrolysis. High-energy ball milling is an efficient, green and simple method for one-step reactions and usually reduces degradation and byproduct formation. Anionic CD derivatives have successfully been synthesized in the solid state, using a planetary ball mill. Comparison with solution reactions, the solvent-free conditions strongly reduced the reagent hydrolysis and resulted in products of higher degree of substitution (DS with more homogeneous DS distribution. The synthesis of anionic CD derivatives can be effectively performed under mechanochemical activation without significant changes to the substitution pattern but the DS distributions were considerably different from the products of solution syntheses.

  19. Genistein in 1:1 Inclusion Complexes with Ramified Cyclodextrins: Theoretical, Physicochemical and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Corina Danciu

    2014-01-01

    Full Text Available Genistein is one of the most studied phytocompound in the class of isoflavones, presenting a notable estrogenic activity and in vitro and/or in vivo benefits in different types of cancer such as those of the bladder, kidney, lung, pancreatic, skin and endometrial cancer. A big inconvenience for drug development is low water solubility, which can be solved by using hydrophilic cyclodextrins. The aim of this study is to theoretically analyze, based on the interaction energy, the possibility of a complex formation between genistein (Gen and three different ramified cyclodextrins (CD, using a 1:1 molar ratio Gen:CD. Theoretical data were correlated with a screening of both in vitro and in vivo activity. Proliferation of different human cancer cell lines, antimicrobial activity and angiogenesis behavior was analyzed in order to see if complexation has a beneficial effect for any of the above mentioned activities and if so, which of the three CDs is the most suitable for the incorporation of genistein, and which may lead to future improved pharmaceutical formulations. Results showed antiproliferative activity with different IC50 values for all tested cell lines, remarkable antimicrobial activity on Bacillus subtilis and antiangiogenic activity as revealed by CAM assay. Differences regarding the intensity of the activity for pure and the three Gen complexes were noticed as explained in the text. The data represent a proof that the three CDs can be used for furtherer research towards practical use in the pharmaceutical and medical field.

  20. Design and development of dry powder sulfobutylether-β-cyclodextrin complex for pulmonary delivery of fisetin.

    Science.gov (United States)

    Mohtar, Noratiqah; Taylor, Kevin M G; Sheikh, Khalid; Somavarapu, Satyanarayana

    2017-04-01

    This study has investigated complexation of fisetin, a natural flavonoid, with three types of cyclodextrins to improve its solubility. Sulfobutylether-β-cyclodextrin (SBE-β-CD) showed the highest complexation efficiency while maintaining the in vitro antioxidant activity of fisetin. Addition of 20%v/v ethanol in water improved the amount of solubilized fisetin in the complex 5.9-fold compared to the system containing water alone. Spray drying of fisetin-SBE-β-CD complex solution in the presence of ethanol produced a dry powder with improved aerosolization properties when delivered from a dry powder inhaler, indicated by a 2-fold increase in the fine particle fraction (FPF) compared to the powder produced from the complex solution containing water alone. The pitted morphological surface of these particles suggested a more hollow internal structure, indicating a lighter and less dense powder. Incorporation of 20%w/w leucine improved the particle size distribution of the powder and further increased the FPF by 2.3-fold. This formulation also showed an EC 50 value equivalent to fisetin alone in the A549 cell line. In conclusion, an inhalable dry powder containing fisetin-SBE-β-CD complex was successfully engineered with an improved aqueous solubility of fisetin. The dry powder may be useful to deliver high amounts of fisetin to the deep lung region for therapeutic purposes. Copyright © 2016. Published by Elsevier B.V.

  1. An Alginate/Cyclodextrin Spray Drying Matrix to Improve Shelf Life and Antioxidant Efficiency of a Blood Orange By-Product Extract Rich in Polyphenols: MMPs Inhibition and Antiglycation Activity in Dysmetabolic Diseases

    Directory of Open Access Journals (Sweden)

    Maria Rosaria Lauro

    2017-01-01

    Full Text Available Alginate and β-cyclodextrin were used to produce easily dosable and spray-dried microsystems of a dried blood orange extract with antidysmetabolic properties, obtained from a by-product fluid extract. The spray-dried applied conditions were able to obtain a concentrate dried extract without the loss of AOA and with TPC and TMA values of 35–40% higher than that of the starting material. They were also effective in producing microparticles with 80–100% of encapsulation efficiency. The 2% sodium alginate was capable of improving the extract shelf life, while the beta-cyclodextrin (1 : 1 molar ratio with dried extract prolonged the extract antioxidant efficiency by 6 hours. The good inhibition effect of the dried extract on the AGE formation and the MMP-2 and MMP-9 activity is presumably due to a synergic effect exerted by both anthocyanin and bioflavonoid extract compounds and was improved by the use of alginate and cyclodextrin.

  2. An Alginate/Cyclodextrin Spray Drying Matrix to Improve Shelf Life and Antioxidant Efficiency of a Blood Orange By-Product Extract Rich in Polyphenols: MMPs Inhibition and Antiglycation Activity in Dysmetabolic Diseases.

    Science.gov (United States)

    Lauro, Maria Rosaria; Crascì, Lucia; Giannone, Virgilio; Ballistreri, Gabriele; Fabroni, Simona; Sansone, Francesca; Rapisarda, Paolo; Panico, Anna Maria; Puglisi, Giovanni

    2017-01-01

    Alginate and β -cyclodextrin were used to produce easily dosable and spray-dried microsystems of a dried blood orange extract with antidysmetabolic properties, obtained from a by-product fluid extract. The spray-dried applied conditions were able to obtain a concentrate dried extract without the loss of AOA and with TPC and TMA values of 35-40% higher than that of the starting material. They were also effective in producing microparticles with 80-100% of encapsulation efficiency. The 2% sodium alginate was capable of improving the extract shelf life , while the beta-cyclodextrin (1 : 1 molar ratio with dried extract) prolonged the extract antioxidant efficiency by 6 hours. The good inhibition effect of the dried extract on the AGE formation and the MMP-2 and MMP-9 activity is presumably due to a synergic effect exerted by both anthocyanin and bioflavonoid extract compounds and was improved by the use of alginate and cyclodextrin.

  3. Sugar-Responsive Pseudopolyrotaxane Composed of Phenylboronic Acid-Modified Polyethylene Glycol and γ-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    Tomohiro Seki

    2015-03-01

    Full Text Available We have designed a sugar-responsive pseudopolyrotaxane (PPRX by combining phenylboronic acid-modified polyethylene glycol (PBA–PEG and γ-cyclodextrin. Phenylboronic acid (PBA was used as a sugar-recognition motif in the PPRX because PBA reacts with a diol portion of the sugar molecule and forms a cyclic ester. When D-fructose or D-glucose was added to a suspension of PPRX, PPRX disintegrated, depending on the concentration of the sugars. Interestingly, catechol does not show a response although catechol has a high affinity for PBA. We analyzed the response mechanism of PPRX by considering equilibria.

  4. Improvement of Aripiprazole Solubility by Complexation with (2-Hydroxy)propyl-β-cyclodextrin Using Spray Drying Technique

    OpenAIRE

    Mihajlovic, Tijana; Kachrimanis, Kyriakos; Graovac, Adrijana; Djuric, Zorica; Ibric, Svetlana

    2012-01-01

    Due to the fact that the number of new poorly soluble active pharmaceutical ingredients is increasing, it is important to investigate the possibilities of improvement of their solubility in order to obtain a final pharmaceutical formulation with enhanced bioavailability. One of the strategies to increase drug solubility is the inclusion of the APIs in cyclodextrins. The aim of this study was to investigate the possibility of aripiprazole solubility improvement by inclusion in (2-hydroxy)propy...

  5. Quality by design in the chiral separation strategy for the determination of enantiomeric impurities: development of a capillary electrophoresis method based on dual cyclodextrin systems for the analysis of levosulpiride.

    Science.gov (United States)

    Orlandini, S; Pasquini, B; Del Bubba, M; Pinzauti, S; Furlanetto, S

    2015-02-06

    Quality by design (QbD) concepts, in accordance with International Conference on Harmonisation Pharmaceutical Development guideline Q8(R2), represent an innovative strategy for the development of analytical methods. In this paper QbD principles have been comprehensively applied in the set-up of a capillary electrophoresis method aimed to quantify enantiomeric impurities. The test compound was the chiral drug substance levosulpiride (S-SUL) and the developed method was intended to be used for routine analysis of the pharmaceutical product. The target of analytical QbD approach is to establish a design space (DS) of critical process parameters (CPPs) where the critical quality attributes (CQAs) of the method have been assured to fulfil the desired requirements with a selected probability. QbD can improve the understanding of the enantioseparation process, including both the electrophoretic behavior of enantiomers and their separation, therefore enabling its control. The CQAs were represented by enantioresolution and analysis time. The scouting phase made it possible to select a separation system made by sulfated-β-cyclodextrin and a neutral cyclodextrin, operating in reverse polarity mode. The type of neutral cyclodextrin was included among other CPPs, both instrumental and related to background electrolyte composition, which were evaluated in a screening phase by an asymmetric screening matrix. Response surface methodology was carried out by a Doehlert design and allowed the contour plots to be drawn, highlighting significant interactions between some of the CPPs. DS was defined by applying Monte-Carlo simulations, and corresponded to the following intervals: sulfated-β-cyclodextrin concentration, 9-12 mM; methyl-β-cyclodextrin concentration, 29-38 mM; Britton-Robinson buffer pH, 3.24-3.50; voltage, 12-14 kV. Robustness of the method was examined by a Plackett-Burman matrix and the obtained results, together with system repeatability data, led to define a method

  6. The role of water in the thermodynamics of drug binding to cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Todorova, Niya A. [Center for Advanced Research in Biotechnology, National Institute of Standards and Technology, 9600 Gudelsky Drive, Rockville, MD 20850 (United States); Schwarz, Frederick P. [Center for Advanced Research in Biotechnology, National Institute of Standards and Technology, 9600 Gudelsky Drive, Rockville, MD 20850 (United States)]. E-mail: fred@carb.nist.gov

    2007-07-15

    The thermodynamic parameters, {delta}{sub B} G {sup 0}, {delta}{sub B} H {sup 0}, {delta}{sub B} S {sup 0}, and {delta}{sub B} C {sub p}, of the drugs flurbiprofen (FLP), nabumetone (NAB), and naproxen (NPX) binding to {beta}-cyclodextrin ({beta}CD) and to {gamma}-cyclodextrin ({gamma}CD) in 0.10 M sodium phosphate buffer were determined from isothermal titration calorimetry (ITC) measurements over the temperature range from 293.15 K to 313.15 K. The heat capacity changes for the binding reactions ranged from -(362 {+-} 48) J . mol{sup -1} . K{sup -1} for FLP and -(238 {+-} 90) J . mol{sup -1} . K{sup -1} for NAB binding in the {beta}CD cavity to 0 for FLP and -(25.1 {+-} 9.2) J . mol{sup -1} . K{sup -1} for NPX binding in the larger {gamma}CD cavity, implying that the structure of water is reorganized in the {beta}CD binding reactions but not reorganized in the {gamma}CD binding reactions. Comparison of the fluorescence enhancements of FLP and NAB upon transferring from the aqueous buffer to isopropanol with the maximum fluorescence enhancements observed for their {beta}CD binding reactions indicated that some localized water was retained in the FLP-{beta}CD complex and almost none in the NAB-{beta}CD complex. No fluorescence change occurs with drug binding in the larger {gamma}CD cavity, indicating the retention of the bulk water environment in the drug-{gamma}CD complex. Since the specific drug binding interactions are essentially the same for {beta}CD and {gamma}CD, these differences in the retention of bulk water may account for the enthalpically driven nature of the {beta}CD binding reactions and the entropically driven nature of the {gamma}CD binding reactions.

  7. [Application of β-cyclodextrin in the formulation of ODT tablets containing ibuprofen].

    Science.gov (United States)

    Zimmer, Łukasz; Kasperek, Regina; Poleszak, Ewa

    2014-01-01

    Oral disintegrating tablet (ODT) dissolves or disintegrates in saliva and then it is swallowed. Diluent in direct compression formulation has a dual role: it increases bulk of the dosage form and it promotes binding of the constituent particles of the formulation. Hence, selection of diluent is important in tablets produced by direct compression method. The aim of this work was to exame feasibility of preparing and optimizing oral disintegrating tablet formulation using β-cyclodextrin as a diluent. 400 mg round tablets were prepared by direct compression method on single punch tablet press using flat plain-face. 60% β-CD and MCC (microcrystalline cellulose - MCC-Vivapur 102) were used at different proportions for all the formulations. 5% of Kollidon CL was added as superdisintegrant. The eight formulations prepared were assessed for weight variation, thickness, disintegration time, hardness and dissolution rate according to FP IX. A dissolution test was performed at 37ºC using the paddle method at 50 rpm with 900 mL phosphate buffer (pH 6.8) as a dissolution medium. The content of ibuprofen sodium was found inside the ± 5% of the theoretical value. Hardness values of presented tablets were in the range 0.11-0.15 kG/mm2. Friability of the tablets lower than 1% indicates that the developed formulations can be processed and handled without excessive care. Disintegration time was in the range of 86 to 161 s. The results confirm the good mechanical properties of tablets containing β-CD. A composition with 20% β-CD and 40% MCC fulfilled a maximum requisite of an optimum formulation. These properties were similar to Ludiflash, the formulation used for comparison purposes. In the present study, higher concentration of β cyclodextrin was found to improve the hardness of tablets without increasing the disintegration time.

  8. Effects of cyclodextrins on the flavor of goat milk and its yogurt.

    Science.gov (United States)

    Young, O A; Gupta, R B; Sadooghy-Saraby, S

    2012-02-01

    Goat milk fat includes several branched chain fatty acids (BCFAs), like 4-methyloctanoic acid, which when free, are responsible for goaty flavor. This flavor limits the market opportunities for goat milk. Prior research showed that cyclodextrins (CDs) can reduce goaty flavor, presumably by binding free fatty acids. This research extends that observation. In odor ranking trials in citrate buffer at pH 4.8, β-CD concentrations between 0% and 0.35% were increasingly effective in reducing odor intensity due to 4-methyloctanoic acid, but only when present in high molar excess. α-CD was also effective, but γ-CD was not. In lipase-treated goat milk only β-CD was effective but at much lower molar excess, a difference potentially explained by several factors. One was that BCFAs bind to CDs in marked preference to their straight chain isomers. Displacement experiments with phenolphthalein disproved that hypothesis. The ability of β-CD to reduce goaty flavor intensity extended to yogurt. An analytical panel showed that flavor of goat yogurt was reduced by addition of β-CD, but only if added before heating and fermentation. A hedonic trial showed that consumers preferred unsweetened and sweet/vanilla-flavored goat yogurt more when β-CD was included, P = 0.004 and 0.016, respectively. Males liked all yogurts more than females (P yogurt: sweet/vanilla masked the goaty flavor for males but not females. This results parallels previously demonstrated gender effects for sheepmeat flavor caused by BCFAs. β-Cyclodextrin masks goaty flavor in yogurt, and with its GRAS status means it could be used in commercial goat yogurts and similar products so the real or perceived nutritional advantages of goat milk are not lost to goaty flavor. © 2012 Institute of Food Technologists®

  9. Effects of modified β-cyclodextrin on thermal stability and conformation of lysozyme

    International Nuclear Information System (INIS)

    Kamiyama, Tadashi; Satoh, Megumi; Tateishi, Takahiro; Nojiri, Tomoaki; Takeuchi, Daisuke; Kimura, Takayoshi

    2012-01-01

    Highlights: ► Effects of cyclodextrin on stability and conformation of lysozyme were clarified. ► The CD influences the hydrophobic interaction of lysozyme by the inclusion. ► The CD relatively destabilized the folded state by stabilizing the unfolded state. ► The destabilization depends on the concentration and the substituent of CD. ► The conformation of lysozyme was more spread at unfolded state by inclusion of CD. - Abstract: Effects of cyclic oligosaccharide cyclodextrin (CD) on stability and conformation of lysozyme were clarified thermodynamically and rheologically by DSC, viscosity, and circular dichroism measurements. The modified β-CD relatively destabilized the folded state of lysozyme by stabilizing the unfolded state due to inclusion of hydrophobic part into the hydrophobic interior of CD. The order of higher destabilization effect was acetyl-β-CD > methyl-β-CD > hydroxypropyl-β-CD. Apparent number of bound CD to unfolded state for methyl-, hydroxypropyl-, and acetyl-β-CD is 6.7 ± 0.7, 4.2 ± 1.1, and 18.6 ± 4.3 and the binding constant is 5.5 ± 0.8, 6.7 ± 2.4, and 4.4 ± 1.2 L mol −1 , respectively. The viscosity for unfolded state was increased with an increase in the each modified β-CD concentration, suggesting that the inclusion of CD on a part of hydrophobic core at unfolded state leads to break the hydrophobic core, then lysozyme would be more spread structure. The substituent of CD can accelerate instability by directly breaking hydrogen bond and/or can restrain instability by increase in hydrophobic interaction. The fact that the each modified CDs has different destabilization effect shows a possibility to control the stability of protein by the substitution of CD.

  10. Cyclodextrin-Containing Polymers: Versatile Platforms of Drug Delivery Materials

    Directory of Open Access Journals (Sweden)

    Jeremy D. Heidel

    2012-01-01

    Full Text Available Nanoparticles are being widely explored as potential therapeutics for numerous applications in medicine and have been shown to significantly improve the circulation, biodistribution, efficacy, and safety profiles of multiple classes of drugs. One leading class of nanoparticles involves the use of linear, cyclodextrin-containing polymers (CDPs. As is discussed in this paper, CDPs can incorporate therapeutic payloads into nanoparticles via covalent attachment of prodrug/drug molecules to the polymer (the basis of the Cyclosert platform or by noncovalent inclusion of cationic CDPs to anionic, nucleic acid payloads (the basis of the RONDEL platform. For each of these two approaches, we review the relevant molecular architecture and its rationale, discuss the physicochemical and biological properties of these nanoparticles, and detail the progress of leading drug candidates for each that have achieved clinical evaluation. Finally, we look ahead to potential future directions of investigation and product candidates based upon this technology.

  11. Antibacterial activity of Nano-Silver capped by β-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    R. Sathiya Priya

    2013-03-01

    Full Text Available Silver nanoparticles were prepared by chemical reduction method using sodium citrate as reducing agent, followed by capping with various concentrations of β-Cyclodextrin (β-CD and characterized by various physicchemical characterization techniques. Antibacterial activity of Pseudomonas aeruginosa (Gram-negative and Staphylococcus aureus (Gram-positive was determined by Well-Diffusion method. The nano-silver were spherical under Scanning electron microscopy (SEM and the XRD result shows average diameters of capped particles are smaller than their equivalent uncapped particles. Capped nano silver particles of four different concentrations were demonstrated as superior for photo stability, when exposed to intense ultraviolet (UV-Vis radiation for 4 hours, as well as significantly higher antibacterial activity. The influence of β-CD concentration (5 mM, 10 mM and 15 mM was seems to be delay in bacterial growth, showing that a Trojan horse mechanism may be owing to occur bacterial affinity, thereby improving silver ion absorption.

  12. From guest to ligand - A study on the competing interactions of antitumor drug resveratrol with β-cyclodextrin and bovine serum albumin

    International Nuclear Information System (INIS)

    Li, Xudong; Li, Hui; Liu, Min; Li, Guangqian; Li, Linwei; Sun, Dezhi

    2011-01-01

    Graphical abstract: Thermodynamic behavior of the interaction between bovine serum albumin and antitumor drug resveratrol delivered by β-cyclodextrin in buffer solutions (pH 7.40) have been investigated by ITC combined with UV, FS and circular dichroism at 298.15 K. The results indicated that the affinity of resveratrol with the host (β-cyclodextrin) was evidently weaker than that of the drug with the both classes of binding sites on the protein molecule. Highlights: → Supramolecular complex of a drug with BSA could form in aqueous medium. → A set of thermodynamic parameters were determined. → Affinity of the drug to β-CD is weaker than that of it to the protein. → The molecular conformation of BSA was (slightly) changed by the drug. - Abstract: Interaction between bovine serum albumin (BSA) and resveratrol (RES) included by β-cyclodextrin (β-CD) in Tris-HCl aqueous buffer solutions (pH 7.4) has been investigated by isothermal titration calorimetry (ITC) combined with ultraviolet, fluorescence and circular dichroism spectra analyses. The results indicate that there are two classes of ligand binding sites. The first class of binding is mainly driven by enthalpy, while the second one is driven by both enthalpy and entropy. The secondary structure of BSA in the aqueous system was slightly changed with addition of the drug. Thermodynamic parameters, i.e., equilibrium constants, standard enthalpy changes and the entropy effects for the binding process of RES with BSA were calculated based on the calorimetric data. In fact, due to the poor solubility of RES in aqueous buffer medium, these parameters could not be determined by the employed experimental method without the existence of the CD.

  13. From guest to ligand - A study on the competing interactions of antitumor drug resveratrol with {beta}-cyclodextrin and bovine serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xudong [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China); Department of Clinical Laboratory, Liaocheng People' s Hospital, Liaocheng, Shandong Province 252000 (China); Li, Hui [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China); Liu, Min, E-mail: liumin_panpan@163.com [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China); Li, Guangqian; Li, Linwei [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China); Sun, Dezhi, E-mail: sundezhisdz@163.com [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong Province 252059 (China)

    2011-07-10

    Graphical abstract: Thermodynamic behavior of the interaction between bovine serum albumin and antitumor drug resveratrol delivered by {beta}-cyclodextrin in buffer solutions (pH 7.40) have been investigated by ITC combined with UV, FS and circular dichroism at 298.15 K. The results indicated that the affinity of resveratrol with the host ({beta}-cyclodextrin) was evidently weaker than that of the drug with the both classes of binding sites on the protein molecule. Highlights: {yields} Supramolecular complex of a drug with BSA could form in aqueous medium. {yields} A set of thermodynamic parameters were determined. {yields} Affinity of the drug to {beta}-CD is weaker than that of it to the protein. {yields} The molecular conformation of BSA was (slightly) changed by the drug. - Abstract: Interaction between bovine serum albumin (BSA) and resveratrol (RES) included by {beta}-cyclodextrin ({beta}-CD) in Tris-HCl aqueous buffer solutions (pH 7.4) has been investigated by isothermal titration calorimetry (ITC) combined with ultraviolet, fluorescence and circular dichroism spectra analyses. The results indicate that there are two classes of ligand binding sites. The first class of binding is mainly driven by enthalpy, while the second one is driven by both enthalpy and entropy. The secondary structure of BSA in the aqueous system was slightly changed with addition of the drug. Thermodynamic parameters, i.e., equilibrium constants, standard enthalpy changes and the entropy effects for the binding process of RES with BSA were calculated based on the calorimetric data. In fact, due to the poor solubility of RES in aqueous buffer medium, these parameters could not be determined by the employed experimental method without the existence of the CD.

  14. Improved thermal stability of polylactic acid (PLA) composite film via PLA-β-cyclodextrin-inclusion complex systems.

    Science.gov (United States)

    Byun, Youngjae; Rodriguez, Katia; Han, Jung H; Kim, Young Teck

    2015-11-01

    The effects of the incorporation of PLA-β-cyclodextrin-inclusion complex (IC) and β-cyclodextrin (β-CD) on biopolyester PLA films were investigated. Thermal stability, surface morphology, barrier, and mechanical properties of the films were measured at varying IC (1, 3, 5, and 7%) and β-CD (1 and 5%) concentrations. The PLA-IC-composite films (IC-PLA-CFs) showed uniform morphological structure, while samples containing β-CD (β-CD-PLA-CFs) showed high agglomeration of β-CD due to poor interfacial interaction between β-CD and PLA moieties. According to the thermal property analysis, the 5% IC-PLA-CFs showed 6.6 times lower dimensional changes (6.5%) at the temperature range of 20-80°C than that of pure PLA film (43.0%). The increase of IC or β-CD content in the PLA-composite films shifted the glass transition and crystallization temperature to higher temperature regions. The crystallinity of both composite films improved by increasing IC or β-CD content. Both composite films had higher oxygen and water vapor permeability as IC or β-CD content increased in comparison to pure PLA film. All the composite films had less flexibility and lower tensile strength than the pure PLA film. In conclusion, this study shows that the IC technique is valuable to improve the thermal expansion stability of PLA-based films. Published by Elsevier B.V.

  15. Cyclodextrin based ternary system of modafinil: Effect of trimethyl chitosan and polyvinylpyrrolidone as complexing agents.

    Science.gov (United States)

    Patel, Parth; Agrawal, Y K; Sarvaiya, Jayrajsinh

    2016-03-01

    Modafinil is an approved drug for the treatment of narcolepsy and have a strong market presence in many countries. The drug is widely consumed for off-label uses and currently listed as a restricted drug. Modafinil has very low water solubility. To enhance the aqueous solubility of modafinil by the formation of a ternary complex with Hydroxypropyl-β-cyclodextrin and two hydrophilic polymers was the main objective of the present study. Pyrrolidone (PVP K30) and a water soluble chitosan derivative, trimethyl chitosan (TMC) were studied by solution state and solid state characterization methods for their discriminatory efficiency in solubility enhancement of modafinil. Phase solubility study depicted the highest complexation efficiency (2.22) of cyclodextrin derivative in the presence of TMC compared to the same in the presence of PVP K30 (0.08) and in the absence of any polymer (0.92). FT-IR analysis of binary and ternary complex expressed comparable contribution of both polymers in formation of inclusion complex. The thermal behaviour of binary and ternary complex, involving individual polymers disclosed the influence of TMC on polymorphism of the drug. DSC study revealed efficiency of TMC to prevent conversion of metastable polymorphic form to stable polymorphic form. Ternary complex, involving TMC enhanced water solubility of the drug 1.5 times more compared to the binary complex of the drug whereas PVP K30 reduced the Solubility. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Estimation of apparent binding constant of complexes of selected acyclic nucleoside phosphonates with beta-cyclodextrin by affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Šolínová, Veronika; Mikysková, Hana; Kaiser, Martin Maxmilian; Janeba, Zlatko; Holý, Antonín; Kašička, Václav

    2016-01-01

    Roč. 37, č. 2 (2016), s. 239-247 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA13-17224S; GA ČR(CZ) GA15-01948S Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * affinity capillary electrophoresis * binding constant * nucleotide analogs * beta-cyclodextrin Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 2.744, year: 2016

  17. NMR Study on the Inclusion Complexes of β-Cyclodextrin with Isoflavones

    Directory of Open Access Journals (Sweden)

    Rui Zhao

    2016-03-01

    Full Text Available The structure of the inclusion complexes of β-cyclodextrin (β-CD with daidzein and daidzin in D2O were investigated using NMR spectroscopy. For the β-CD and daidzein system, two types of 1:1 complexes were formed with the daidzein deeply inserted into the CD cavity with different orientations. For the β-CD/daidzin system, a 1:1 complex was formed with the flavonoid part of daidzin entering the CD cavity from the wide rim. The inclusion complexes determined by NMR were constructed using molecular docking. Furthermore, the mixture of puerarin, daidzein and daidzin, which are the major isoflavonoid components present in Radix puerariae, was analyzed by diffusion-ordered spectroscopy (DOSY alone and upon addition of β-CD in order to mimic chromatographic conditions and compare their binding affinities.

  18. β-Cyclodextrin-dextran polymers for the solubilization of poorly soluble drugs

    DEFF Research Database (Denmark)

    Di Cagno, Massimiliano; Nielsen, Thorbjørn Terndrup; Lambertsen Larsen, Kim

    2014-01-01

    The aim of this work was to assess the potential of β-cyclodextrin (β-CD)-dextran polymers for drug delivery, in terms of molecular mass, the complexation reaction mechanism using a model drug, and solubilization efficiency for examples of poorly soluble model drugs. For this purpose size analysis...... of different β-CD-dextrans was carried out by both size exclusion chromatography (SEC) and flow field-flow fractionation (FFF). All investigated polymers were of appropriate sizes for potential parenteral administration. Mass/mass percentage ratio between β-CD units and dextran backbones where measured by both...... of solubilization efficiencies, phase-solubility diagrams where made employing two poorly soluble model drugs, one dissociating (ibuprofen, IBP) and one pH independent (hydrocortisone, HC). Thermodynamic results demonstrated that the presence of the dextran-back bone structure improves complexation efficiency...

  19. Propriedades e aplicações recentes das ciclodextrinas Properties and recent applications of cyclodextrins

    Directory of Open Access Journals (Sweden)

    Cristina de Garcia Venturini

    2008-01-01

    Full Text Available Cyclodextrins (CDs are cyclic oligosaccharides comprised of six or more glucose units connected by alpha-1,4 bonds. They have hydrophobic cavities with a hydrophilic exterior, and are versatile receptors for a variety of substrates. This ability allows them to be applied in many fields, as distinct as supramolecular chemistry, nanotechnology, pharmaceuticals, green chemistry, agrochemicals, analytical chemistry, toiletries, foods, and cosmetics. This review summarizes several aspects related to the physico-chemical properties of CDs and discusses their potential applications illustrated by recent examples. The prospects for their use in several areas are also described.

  20. The hydroxypropyl–β-cyclodextrin complexation of toltrazuril for enhancing bioavailability

    Directory of Open Access Journals (Sweden)

    Zhang L

    2018-03-01

    Full Text Available Li Zhang,1,2,* Mengxi Liu,1,* Chaocheng Lu,1 Dandan Ren,1 Guoqing Fan,1 Chang Liu,1 Mengjiao Liu,1 Gang Shu,1 Guangneng Peng,1 Zhixiang Yuan,1 Zhijun Zhong,1 Wei Zhang,1 Hualin Fu1 1Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; 2Institute of Traditional Chinese Medicine Pharmacology and Toxicology, Sichuan Academy of Chinese Medicine Sciences, Chengdu, Sichuan, China *These authors contributed equally to this work Introduction: Toltrazuril (Tol is used to prevent and combat coccidiosis. However, its low aqueous solubility and poor oral bioavailability limit clinical application. Methods: To overcome the shortcomings, toltrazuril–hydroxypropyl–β-cyclodextrin inclusion complex (Tol-HP-β-CD was prepared and characterized. The comparative plasma disposition kinetics of Tol was analyzed after a single orally administered dose of 10 mg/kg Tol or Tol-HP-β-CD in rabbits. Solution-stirring method was selected to prepare the inclusion complex. Complex formation was characterized by thin-layer chromatography, Fourier transform infrared spectrophotometry, and 1H nuclear magnetic resonance spectroscopy. In plasma profile, plasma samples were collected between 1 and 10 days following administration. Plasma Tol concentrations were determined by high-performance liquid chromatography. Results: In rabbit plasma, the time to peak concentration (Tmax of Tol-HP-β-CD was shorter than that of Tol (12 h vs 24 h. Cmax (19.92±1.02 µg/mL and area under the concentration–time curve (AUC0-∞, 1,176.86±70.26 mg/L h of the Tol-HP-β-CD group significantly increased (p<0.01 than those of the Tol group (Cmax, 8.02±1.04 µg/mL; AUC0-∞, 514.03±66.65 mg/L h. Conclusion: It can be concluded that the Tol-HP-β-CD increased the aqueous solubility and enhanced the oral bioavailability in rabbits. Complexation with HP-β-CD is a feasible way to prepare a rapidly absorbed and more bioavailable Tol

  1. Polypseudorotaxanes between .alpha.-cyclodextrin and poly(propylene glycol)-b-poly(ethylene glycol)-b-poly(propylene glycol) copolymers studied by MALDI-TOF mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Horský, Jiří; Walterová, Zuzana

    2016-01-01

    Roč. 74, January (2016), s. 256-263 ISSN 0014-3057 Grant - others:OPPK(XE) CZ.2.16/3.1.00/24504 Institutional support: RVO:61389013 Keywords : polypseudorotaxanes * reverse pluronics * cyclodextrin Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.531, year: 2016

  2. β-Cyclodextrin (β-CD): A new approach in bread staling

    International Nuclear Information System (INIS)

    Tian, Y.Q.; Li, Y.; Jin, Z.Y.; Xu, X.M.; Wang, J.P.; Jiao, A.Q.; Yu, B.; Talba, T.

    2009-01-01

    In this study, the impact of the addition of β-cyclodextrin (β-CD) on bread staling was investigated by texture profile analysis (TPA), X-ray diffraction (XRD), and differential scanning calorimeter (DSC). Results showed that the retardation effect of β-CD on bread staling was found to be significant as less changes of hardness, cohesiveness and springiness were observed during the storage. The addition of β-CD also significantly decreased recrystallization rate k, and increased Avrami exponent n, indicating that the nucleation type was transformed. Investigated by X-ray diffraction, changes of crystalline patterns occurring in crust and crumb were retarded by the development of A + V and B + V intermediate patterns for stored crust and stored crumb, respectively. This retardation was attributed to the amylose-lipid-β-CD complex formation observed and analyzed by DSC technique, resulting in nucleation type transformation and lowering the rate of bread staling.

  3. Electrochemical Evidence of Host-Guest Interactions. Change of Redox Mechanism of Fungicides Iprodione and Procymidone in the Nano-cavity of Cyclodextrins

    Czech Academy of Sciences Publication Activity Database

    Hromadová, Magdaléna; Pospíšil, Lubomír; Giannarelli, S.; Fuoco, R.; Colombini, M. P.

    2002-01-01

    Roč. 73, - (2002), s. 213-219 ISSN 0026-265X R&D Projects: GA MŠk OC D15.10; GA ČR GP203/02/P082 Institutional research plan: CEZ:AV0Z4040901 Keywords : electrochemical evidence * fungicide * cyclodextrin Subject RIV: CG - Electrochemistry Impact factor: 1.325, year: 2002

  4. Effect of antioxidant activity of caffeic acid with cyclodextrins using ground mixture method

    Directory of Open Access Journals (Sweden)

    Ryota Shiozawa

    2018-01-01

    Full Text Available In the current study, we prepared a ground mixture (GM of caffeic acid (CA with α-cyclodextrin (αCD and with β-cyclodextrin (βCD, and then comparatively assessed the physicochemical properties and antioxidant capacities of these GMs. Phase solubility diagrams indicated that both CA/αCD and CA/βCD formed a complex at a molar ratio of 1/1. In addition, stability constants suggested that CA was more stable inside the cavity of αCD than inside the cavity of βCD. Results of powder X-ray diffraction (PXRD indicated that the characteristic diffraction peaks of CA and CD disappeared and a halo pattern was produced by the GMs of CA/αCD and CA/βCD (molar ratios = 1/1. Dissolution testing revealed that both GMs had a higher rate of dissolution than CA alone did. Based on the 1H-1H NOESY NMR spectra for the GM of CA/αCD, the vinylene group of the CA molecule appeared to be included from the wider to the narrower rim of the αCD ring. Based on spectra for the GM of CA/βCD, the aromatic ring of the CA molecule appeared to be included from the wider to the narrower rim of the βCD ring. This suggests that the structures of the CA inclusion complexes differed between those involving αCD rings and those involving βCD rings. Results of a DPPH radical-scavenging activity test indicated that the GM of CA/αCD had a higher antioxidant capacity than that of the GM of CA/βCD. The differences in the antioxidant capacities of the GMs of CA/αCD and CA/βCD are presumably due to differences in stability constants and structures of the inclusion complexes.

  5. Spray-Freeze Drying: a Suitable Method for Aerosol Delivery of Antibodies in the Presence of Trehalose and Cyclodextrins.

    Science.gov (United States)

    Pouya, Maryam Amini; Daneshmand, Behnaz; Aghababaie, Shabnam; Faghihi, Homa; Vatanara, Alireza

    2018-05-08

    We aimed to prepare spray-freeze-dried powder of IgG considering physicochemical stability and aerodynamic aspects. Spray-freeze drying (SFD) exposes proteins to various stresses which should be compensated by suitable stabilizers. The competence of cyclodextrins (CDs), namely beta-cyclodextrin (βCD) and hydroxypropyl βCD (HPβCD), at very low concentrations, was investigated in the presence of separate mannitol- and trehalose-based formulations. Spray-freeze-dried preparations were quantified in terms of monomer recovery and conformation by size exclusion chromatography (SEC-HPLC) and Fourier transform infrared (FTIR) spectroscopy, respectively. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) were employed to identify the thermal characteristics of powders. Particle morphology was visualized by scanning electron microscopy (SEM). Aerodynamic behavior of powders was checked through an Anderson cascade impactor (ACI). Although all formulations protected antibody from aggregation during the SFD process (aggregation < 1%), mannitol-containing ones failed upon the storage (19.54% in the worst case). Trehalose-HPβCD incomparably preserved the formulation with fine particle fraction (FPF) of 51.29%. Crystallization of mannitol resulted in IgG destabilization upon storage. Although employed concentration of CDs is too low (less than 50:1 molar ratio to protein), they successfully served as stabilizing agents in SFD with perfect improvement in aerosol functionality. Graphical Abstract ᅟ.

  6. In vitro and in vivo studies on the complexes of glipizide with water-soluble β-cyclodextrin-epichlorohydrin polymers.

    Science.gov (United States)

    Nie, Shufang; Zhang, Shu; Pan, Weisan; Liu, Yanli

    2011-05-01

    The purpose of this study was to evaluate the potential of a newly modified cyclodextrin derivative, water-soluble β-cyclodextrin-epichlorohydrin polymer (β-CDP), as an effective drug carrier to enhance the dissolution rate and oral bioavailability of glipizide as a poorly water-soluble model drug. Inclusion complexes of glipizide with β-CDP were prepared by the co-evaporation method and characterized by phase solubility, dissolution, and differential scanning calorimetry. The solubility curve was classified as type A(L), which indicated the formation of 1:1 complex between glipizide and β-CDP. β-CDP had better properties of increasing the aqueous solubility of glipizide compared with HP-β-CD. The dissolution rate of drug from the β-CDP complexes was significantly greater than that of the corresponding physical mixtures indicating that the formation of amorphous complex increased the solubility of glipizide. Moreover, the increment in drug dissolution rate from the glipizide/β-CDP systems was higher than that from the corresponding ones with HP-β-CD, which indicated that β-CDP could provide greater capability of solubilization for poorly soluble drugs. Furthermore, in vivo study revealed that the bioavailability of glipizide was significantly improved by glipizide /β-CDP inclusion complex after oral administration to beagle dogs.

  7. Attached β-cyclodextrin/γ-(2,3-epoxypropoxy) propyl trimethoxysilane to graphene oxide and its application in copper removal.

    Science.gov (United States)

    Yu, Zongxue; Chen, Qi; Lv, Liang; Pan, Yang; Zeng, Guangyong; He, Yi

    2017-05-01

    The environmental applications of graphene oxide and β-cyclodextrin (β-CD) have attracted great attention since their first discovery. Novel nanocomposites were successfully prepared by using an esterification reaction between β-cyclodextrin/γ-(2,3-epoxypropoxy) propyl trimethoxysilane grafted graphene oxide (β-CD/GPTMS/GO). The β-CD/GPTMS/GO nanocomposites were used to remove the Cu 2+ from aqueous solutions. The characteristics of β-CD/GPTMS/GO were detected by scanning electron microscopy (SEM), Fourier transform infrared, X-ray diffraction (XRD), thermogravimetric analysis (TG) and energy dispersive X-ray (EDX). The dispersibility of graphene oxide was excellent due to the addition of β-CD. The adsorption isotherms data obtained at the optimum pH 7 were fitted by Langmuir isotherm model. The excellent adsorption properties of β-CD/GPTMS/GO for Cu 2+ ions could be attributed to the apolar cavity structure of β-CD, the high surface area and abundant functional groups on the surface of GO. The adsorption patterns of β-CD/GPTMS/GO were electrostatic attraction, formation of host-guest inclusion complexes and the ion exchange adsorption. The efficient adsorption of β-CD/GPTMS/GO for Cu 2+ ions suggested that these novel nanocomposites may be ideal candidates for removing other cation pollutants from waste water.

  8. New ethanol and propylene glycol free gel formulations containing a minoxidil-methyl-β-cyclodextrin complex as promising tools for alopecia treatment.

    Science.gov (United States)

    Lopedota, Angela; Cutrignelli, Annalisa; Denora, Nunzio; Laquintana, Valentino; Lopalco, Antonio; Selva, Stefano; Ragni, Lorella; Tongiani, Serena; Franco, Massimo

    2015-05-01

    New topical totally aqueous formulations that improve the low water solubility of minoxidil and realize an adequate permeability of drug in the skin are proposed. These formulations are lacking in propylene glycol and alcohol that are the principal irritant ingredients present in minoxidil commercial solutions. In order to enhance poor water solubility of minoxidil randomly methyl-β-cyclodextrin was used, and four hydrogels such as, calcium alginate, sodium alginate, carbopol 934 and hydroxyethylcellulose were utilized to ensure a prolonged time of contact with the scalp. The inclusion complex minoxidil/methyl-β-cyclodextrin with a molar ratio 1:1 was obtained by freeze drying and evaluated by NMR, FT-IR and DSC analysis. An apparent stability constant of formed inclusion complex was calculated by phase solubility diagram and its value was 400 M(-1). The solid inclusion complex was used to prepare gel formulations with similar dose to minoxidil commercial solution. The gels were evaluated for various technological parameters including rheological behavior, in vitro drug release and ex vivo permeation through pig skin. The best performance was observed for the calcium alginate formulation.

  9. Poly-dopamine-beta-cyclodextrin: A novel nanobiopolymer towards sensing of some amino acids at physiological pH

    International Nuclear Information System (INIS)

    Hasanzadeh, Mohammad; Sadeghi, Sattar; Bageri, Leyla; Mokhtarzadeh, Ahad; Karimzadeh, Ayub; Shadjou, Nasrin; Mahboob, Soltanali

    2016-01-01

    A novel nanobiopolymer film was electrodeposited on the surface of glassy carbon through cyclic voltammetry from dopamine, β-cyclodextrin, and phosphate buffer solution in physiological pH (7.40). The electrochemical behavior of polydopamine-Beta-cyclodextrin modified glassy carbon electrode was investigated for electro-oxidation and determination of some amino acids (L-Cysteine, L-Tyrosine, L-Glycine, and L-Phenylalanine). The modified electrode was applied for selected amino acid detection at physiological pH using cyclic voltammetry, differential pulse voltammetry and chronoamperometry, chronocoulometery. The linear concentration range of the proposed sensor for the L-Glycine, L-Cysteine, L-Tyrosine, and L-Phenylalanine were 0.2–70, 0.06–0.2, 0.01–0.1, and 0.2–10 μM, while low limit of quantifications were 0.2, 0.06, 0.01, and 0.2 μM, respectively. The modified electrode shows many advantages as an amino acid sensor such as simple preparation method without using any specific electron transfer mediator or specific reagent, good sensitivity, short response time, and long term stability. - Highlights: • A novel biopolymer film with entitled PDA-β-CD was electrodeposited on the GCE. • Synergetic effect of β-CD and GQD on the electrical signal amplifications was investigated. • The performance of β-CD-GQD-GCE towards electrochemical sensing of some amino acids was investigated.

  10. Poly-dopamine-beta-cyclodextrin: A novel nanobiopolymer towards sensing of some amino acids at physiological pH

    Energy Technology Data Exchange (ETDEWEB)

    Hasanzadeh, Mohammad, E-mail: mhmmd_hasanzadeh@yahoo.com [Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz 51664 (Iran, Islamic Republic of); Pharmaceutical Analysis Research Center, Tabriz University of Medical Sciences, Tabriz 51664 (Iran, Islamic Republic of); Sadeghi, Sattar [Department of Biochemistry, Higher Education Institute of Rab-Rashid, Tabriz (Iran, Islamic Republic of); Bageri, Leyla [Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz 51664 (Iran, Islamic Republic of); Mokhtarzadeh, Ahad [School of Medicine, Gonabad University of Medical Sciences, Gonabad (Iran, Islamic Republic of); Department of Biochemistry, Higher Education Institute of Rab-Rashid, Tabriz (Iran, Islamic Republic of); Karimzadeh, Ayub [Department of Biochemistry, Higher Education Institute of Rab-Rashid, Tabriz (Iran, Islamic Republic of); Shadjou, Nasrin [Department of Nanochemistry, Nano Technology Research Center, Urmia University, Urmia 57154 (Iran, Islamic Republic of); Department of Nano Technology, Faculty of Science, Urmia University, Urmia 57154 (Iran, Islamic Republic of); Mahboob, Soltanali [Department of Biochemistry, Higher Education Institute of Rab-Rashid, Tabriz (Iran, Islamic Republic of)

    2016-12-01

    A novel nanobiopolymer film was electrodeposited on the surface of glassy carbon through cyclic voltammetry from dopamine, β-cyclodextrin, and phosphate buffer solution in physiological pH (7.40). The electrochemical behavior of polydopamine-Beta-cyclodextrin modified glassy carbon electrode was investigated for electro-oxidation and determination of some amino acids (L-Cysteine, L-Tyrosine, L-Glycine, and L-Phenylalanine). The modified electrode was applied for selected amino acid detection at physiological pH using cyclic voltammetry, differential pulse voltammetry and chronoamperometry, chronocoulometery. The linear concentration range of the proposed sensor for the L-Glycine, L-Cysteine, L-Tyrosine, and L-Phenylalanine were 0.2–70, 0.06–0.2, 0.01–0.1, and 0.2–10 μM, while low limit of quantifications were 0.2, 0.06, 0.01, and 0.2 μM, respectively. The modified electrode shows many advantages as an amino acid sensor such as simple preparation method without using any specific electron transfer mediator or specific reagent, good sensitivity, short response time, and long term stability. - Highlights: • A novel biopolymer film with entitled PDA-β-CD was electrodeposited on the GCE. • Synergetic effect of β-CD and GQD on the electrical signal amplifications was investigated. • The performance of β-CD-GQD-GCE towards electrochemical sensing of some amino acids was investigated.

  11. Neutron diffraction of α, β and γ cyclodextrins: hydrogen bonding patterns

    International Nuclear Information System (INIS)

    Hingerty, B.E.; Klar, B.; Hardgrove, G.; Betzel, C.; Saenger, W.

    1983-01-01

    Cyclodextrins (CD's) are torus-shaped molecules composed of six (α), seven (β) or eight (γ) (1 → 4) linked glucoses. α-CD has been shown to have two different structures with well-defined hydrogen bonds, one tense and the other relaxed. An induced-fit-like mechanism for α-CD complex formation has been proposed. Circular hydrogen bond networks have also been found for α-CD due to the energetically favored cooperative effect. β-CD with a disordered water structure possesses an unusual flip-flop hydrogen bonding system of the type O-H H-O representing an equilibrium between two states; O-H O reversible H-O. γ-CD with a disordered water structure similar to β-CD also possesses the flip-flop hydrogen bond. This study demonstrates that hydrogen bonds are operative in disordered systems and display dynamics even in the solid state

  12. Enhancement of Solubility, Dissolution rate and Bioavailability of Efavirenz by Cyclodextrins and Solutol HS15 - A Factorial Study

    OpenAIRE

    R. Yogananda; K. P. R. Chowdary

    2013-01-01

    Efavirenz widely prescribed anti-retroviral drug belongs to class II BCS and exhibit low and variable oral bioavailability due to its poor aqueous solubility and it requires enhancement in solubility and dissolution rate for increasing its oral bioavailability. The objective of the present investigation is to enhance the solubility, dissolution rate and bioavailability of efavirenz by the use of cyclodextrins (%CD and HP%CD) and surfactant, Solutol HS15. The individual main effects and combin...

  13. Selective Surface Acoustic Wave-Based Organophosphorus Sensor Employing a Host-Guest Self-Assembly Monolayer of β-Cyclodextrin Derivative

    Directory of Open Access Journals (Sweden)

    Yong Pan

    2015-07-01

    Full Text Available Self-assembly and molecular imprinting technologies are very attractive technologies for the development of artificial recognition systems and provide chemical recognition based on need and not happenstance. In this paper, we employed a b-cyclodextrin derivative surface acoustic wave (SAW chemical sensor for detecting the chemical warfare agents (CWAs sarin (O-Isoprophyl methylphosphonofluoridate, GB. Using sarin acid (isoprophyl hydrogen methylphosphonate as an imprinting template, mono[6-deoxy-6-[(mercaptodecamethylenethio

  14. Delivery of cyclodextrin polymers to bacterial biofilms - An exploratory study using rhodamine labelled cyclodextrins and multiphoton microscopy.

    Science.gov (United States)

    Thomsen, Hanna; Benkovics, Gábor; Fenyvesi, Éva; Farewell, Anne; Malanga, Milo; Ericson, Marica B

    2017-10-15

    Cyclodextrin (CD) polymers are interesting nanoparticulate systems for pharmaceutical delivery; however, knowledge regarding their applications towards delivery into complex microbial biofilm structures is so far limited. The challenge is to demonstrate penetration and transport through the biofilm and its exopolysaccharide matrix. The ideal functionalization for penetration into mature biofilms is unexplored. In this paper, we present a novel set of rhodamine labelled βCD-polymers, with different charge moieties, i.e., neutral, anionic, and cationic, and explore their potential delivery into mature Staphylococcus epidermidis biofilms using multiphoton laser scanning microscopy (MPM). The S. epidermidis biofilms, being a medically relevant model organism, were stained with SYTO9. By using MPM, three-dimensional imaging and spectral investigation of the distribution of the βCD-polymers could be obtained. It was found that the cationic βCD-polymers showed significantly higher integration into the biofilms, compared to neutral and anionic functionalized βCDs. None of the carriers presented any inherent toxicity to the biofilms, meaning that the addition of rhodamine moiety does not affect the inertness of the delivery system. Taken together, this study demonstrates a novel approach by which delivery of fluorescently labelled CD nanoparticles to bacterial biofilms can be explored using MPM. Future studies should be undertaken investigating the potential in using cationic functionalization of CD based delivery systems for targeting anti-microbial effects in biofilms. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Structural and spectroscopic features of lutein/butanoyl-β-cyclodextrin nanoassemblies

    DEFF Research Database (Denmark)

    Stancanelli, R.; Løjkner, L.D.; Larsen, Kim Lambertsen

    2012-01-01

    Lutein, the primary carotenoid present in the central area of the retina of eye appears to be associated with the protection against age-related macular degeneration (the leading cause of blindness in older adults). Its lipophilicity and consequently its scarce water solubility (1.3 × 10−9 M......-cyclodextrins (C4:7) form in water nanoaggregates with a average size of 250 nm and a ζ-potential of about −6 mV. They are able to entrap lutein at 1:6 Lut/ACyD molar ratio by yielding nanoassemblies of vesicular aspect (320 nm and −8 mV) such as observed by static, dynamic and electrophoretic light-scattering. UV......–vis measurements revealed that electronic properties of lutein were maintained when interact with ACyD nanoaggregates. The monitoring of the entapped carotenoid leaking from ACyD nanostructures was investigated suggesting the potential of Lut/ACyD nanoassemblies in drug delivery....

  16. Nootkatone encapsulation by cyclodextrins: Effect on water solubility and photostability.

    Science.gov (United States)

    Kfoury, Miriana; Landy, David; Ruellan, Steven; Auezova, Lizette; Greige-Gerges, Hélène; Fourmentin, Sophie

    2017-12-01

    Nootkatone (NO) is a sesquiterpenoid volatile flavor, used in foods, cosmetics and pharmaceuticals, possessing also insect repellent activity. Its application is limited because of its low aqueous solubility and stability; this could be resolved by encapsulation in cyclodextrins (CDs). This study evaluated the encapsulation of NO by CDs using phase solubility studies, Isothermal Titration Calorimetry, Nuclear Magnetic Resonance spectroscopy and molecular modeling. Solid CD/NO inclusion complex was prepared and characterized for encapsulation efficiency and loading capacity using UV-Visible. Thermal properties were investigated by thermogravimetric-differential thermal analysis and release studies were performed using multiple headspace extraction. Formation constants (K f ) proved the formation of stable inclusion complexes. NO aqueous solubility, photo- and thermal stability were enhanced and the release could be insured from solid complex in aqueous solution. This suggests that CDs are promising carrier to improve NO properties and, consequently, to enlarge its use in foods, cosmetics, pharmaceuticals and agrochemicals preparations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Influence of intramolecular hydrogen bonds on the binding potential of methylated β-cyclodextrin derivatives

    Directory of Open Access Journals (Sweden)

    Gerhard Wenz

    2012-11-01

    Full Text Available Various heptasubstituted derivatives of β-cyclodextrin (β-CD bearing 1, 2 and 3 methyl substituents per glucose unit were synthesized by regioselective methods. Binding free energies and binding enthalpies of these hosts towards 4-tert-butylbenzoate and adamantane-1-carboxylate were determined by isothermal titration microcalorimetry (ITC. It was found that methyl substituents at the secondary positions of β-CD lead to a tremendous reduction of the binding potential, while methylation at the primary positions significantly improved binding. Stabilizing intramolecular hydrogen bonds between the glucose units were made responsible for the high binding potentials of those β-CD derivatives that possess secondary hydroxy groups.

  18. Oligomerization of optically active N-(4-hydroxyphenylmandelamide in the presence of β-cyclodextrin and the minor role of chirality

    Directory of Open Access Journals (Sweden)

    Helmut Ritter

    2014-10-01

    Full Text Available The oxidative oligomerization of a chiral mandelamide derivative (N-(4-hydroxyphenylmandelamide, 1 was performed in the presence of horseradish peroxidase, laccase and N,N'-bis(salicylideneethylenediamine-iron(II to obtain chiral oligophenols 2. The low enantioselectivity of the enzymatic catalyzed asymmetric enantiomer-differentiating oligomerizations was investigated. In addition, the poor influence of cyclodextrin on the enantioselectivity of enzymatic catalyzed asymmetric enantiomer-differentiating oligomerizations was studied.

  19. Cyclodextrin Protects Podocytes in Diabetic Kidney Disease

    Science.gov (United States)

    Merscher-Gomez, Sandra; Guzman, Johanna; Pedigo, Christopher E.; Lehto, Markku; Aguillon-Prada, Robier; Mendez, Armando; Lassenius, Mariann I.; Forsblom, Carol; Yoo, TaeHyun; Villarreal, Rodrigo; Maiguel, Dony; Johnson, Kevin; Goldberg, Ronald; Nair, Viji; Randolph, Ann; Kretzler, Matthias; Nelson, Robert G.; Burke, George W.; Groop, Per-Henrik; Fornoni, Alessia

    2013-01-01

    Diabetic kidney disease (DKD) remains the most common cause of end-stage kidney disease despite multifactorial intervention. We demonstrated that increased cholesterol in association with downregulation of ATP-binding cassette transporter ABCA1 occurs in normal human podocytes exposed to the sera of patients with type 1 diabetes and albuminuria (DKD+) when compared with diabetic patients with normoalbuminuria (DKD−) and similar duration of diabetes and lipid profile. Glomerular downregulation of ABCA1 was confirmed in biopsies from patients with early DKD (n = 70) when compared with normal living donors (n = 32). Induction of cholesterol efflux with cyclodextrin (CD) but not inhibition of cholesterol synthesis with simvastatin prevented podocyte injury observed in vitro after exposure to patient sera. Subcutaneous administration of CD to diabetic BTBR (black and tan, brachiuric) ob/ob mice was safe and reduced albuminuria, mesangial expansion, kidney weight, and cortical cholesterol content. This was followed by an improvement of fasting insulin, blood glucose, body weight, and glucose tolerance in vivo and improved glucose-stimulated insulin release in human islets in vitro. Our data suggest that impaired reverse cholesterol transport characterizes clinical and experimental DKD and negatively influences podocyte function. Treatment with CD is safe and effective in preserving podocyte function in vitro and in vivo and may improve the metabolic control of diabetes. PMID:23835338

  20. Osmotic properties of sulfobutylether and hydroxypropyl cyclodextrins.

    Science.gov (United States)

    Zannou, E A; Streng, W H; Stella, V J

    2001-08-01

    The purpose of this study was to determine the osmolality of sulfobutylether (SBE) and hydroxypropyl (HP) derivatives of cyclodextrins (CDs) via vapor pressure osmometry (VPO) and freezing point depression (FPD). (SBE) and HP-CDs are efficient excipients capable of solubilizing and stabilizing poorly water-soluble drugs in parenteral formulations. (SBE)-CDs have also been used as solubility enhancers and osmotic agents for the sustained release of poorly water-soluble drugs from osmotic pump tablets. The knowledge of the CD's osmolality in solution or inside such tablets would allow one to further characterize the release mechanisms. Experiments were conducted at 37 degrees C with eight types of HP and (SBE)-CDs. The aqueous solutions ranged from 0.005-0.350 mol(-1). Methods were developed to allow the measurement of high osmolalities using a vapor pressure osmometer or a differential scanning calorimeter. The osmolality calculations from the VPO and FPD measurements correlated well. The osmolality of (SBE)-CDs was significantly higher than the osmolality of HP-CDs and increased with the total degree of substitution (TDS). All CDs showed deviations from ideality at high concentrations. Empirical correlations of osmolality with concentration and TDS allowed the prediction of osmolality over a wide concentration range. This study also gave some useful insights into the behavior of CD derivatives in solution.

  1. The formation of amino acid and dipeptide complexes with α-cyclodextrin and cucurbit[6]uril in aqueous solutions studied by titration calorimetry

    International Nuclear Information System (INIS)

    Buschmann, H.-J.; Schollmeyer, E.; Mutihac, L.

    2003-01-01

    The complex stabilities and the thermodynamic data for the complexation of α-cyclodextrin and cucurbit[6]uril with some amino acids (glycine, L-alanine, L-valine, L-phenylalanine, 6-amino hexanoic acid, 8-amino octanoic acid, 11-amino undecanoic acid) and dipeptides (glycyl-glycine, glycyl-L-valine, glycyl-L-leucine and glycyl-L-phenylalanine) have been determined in aqueous solution by calorimetric titrations. The complex formation with α-cyclodextrin is mainly favoured by entropic contributions due to the release of water molecules from the cavity of the ligand. The values of the reaction enthalpies are small with the exception of 11-amino undecanoic acid. In case of the ligand cucurbit[6]uril, ion-dipole interactions between the protonated amino groups of the amino acids and the carbonyl groups take place. By steric reasons these interactions are lowered for native amino acids because the polar carboxylic groups are always located outside the hydrophobic cavity of cucurbit[6]uril. The complexes of both ligands with dipeptides in water are characterised by hydrophobic interactions and in case of cucurbit[6]uril by additional ion-dipole interactions

  2. Fluorescence enhancement upon G-quadruplex folding: synthesis, structure, and biophysical characterization of a dansyl/cyclodextrin-tagged thrombin binding aptamer.

    Science.gov (United States)

    De Tito, Stefano; Morvan, François; Meyer, Albert; Vasseur, Jean-Jacques; Cummaro, Annunziata; Petraccone, Luigi; Pagano, Bruno; Novellino, Ettore; Randazzo, Antonio; Giancola, Concetta; Montesarchio, Daniela

    2013-11-20

    A novel fluorescent thrombin binding aptamer (TBA), conjugated with the environmentally sensitive dansyl probe at the 3'-end and a β-cyclodextrin residue at the 5'-end, has been efficiently synthesized exploiting Cu(I)-catalyzed azide-alkyne cycloaddition procedures. Its conformation and stability in solution have been studied by an integrated approach, combining in-depth NMR, CD, fluorescence, and DSC studies. ITC measurements have allowed us to analyze in detail its interaction with human thrombin. All the collected data show that this bis-conjugated aptamer fully retains its G-quadruplex formation ability and thrombin recognition properties, with the terminal appendages only marginally interfering with the conformational behavior of TBA. Folding of this modified aptamer into the chairlike, antiparallel G-quadruplex structure, promoted by K(+) and/or thrombin binding, typical of TBA, is associated with a net fluorescence enhancement, due to encapsulation of dansyl, attached at the 3'-end, into the apolar cavity of the β-cyclodextrin at the 5'-end. Overall, the structural characterization of this novel, bis-conjugated TBA fully demonstrates its potential as a diagnostic tool for thrombin recognition, also providing a useful basis for the design of suitable aptamer-based devices for theranostic applications, allowing simultaneously both detection and inhibition or modulation of the thrombin activity.

  3. Novel medium-throughput technique for investigating drug-cyclodextrin complexation by pH-metric titration using the partition coefficient method.

    Science.gov (United States)

    Dargó, Gergő; Boros, Krisztina; Péter, László; Malanga, Milo; Sohajda, Tamás; Szente, Lajos; Balogh, György T

    2018-05-05

    The present study was aimed to develop a medium-throughput screening technique for investigation of cyclodextrin (CD)-active pharmaceutical ingredient (API) complexes. Dual-phase potentiometric lipophilicity measurement, as gold standard technique, was combined with the partition coefficient method (plotting the reciprocal of partition coefficients of APIs as a function of CD concentration). A general equation was derived for determination of stability constants of 1:1 CD-API complexes (K 1:1,CD ) based on solely the changes of partition coefficients (logP o/w N -logP app N ), without measurement of the actual API concentrations. Experimentally determined logP value (-1.64) of 6-deoxy-6[(5/6)-fluoresceinylthioureido]-HPBCD (FITC-NH-HPBCD) was used to estimate the logP value (≈ -2.5 to -3) of (2-hydroxypropyl)-ß-cyclodextrin (HPBCD). The results suggested that the amount of HPBCD can be considered to be inconsequential in the octanol phase. The decrease of octanol volume due to the octanol-CD complexation was considered, thus a corrected octanol-water phase ratio was also introduced. The K 1:1,CD values obtained by this developed method showed a good accordance with the results from other orthogonal methods. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Characterizing the interaction between enantiomers of eight psychoactive drugs and highly sulfated-β-cyclodextrin by counter-current capillary electrophoresis.

    Science.gov (United States)

    Asensi-Bernardi, Lucía; Escuder-Gilabert, Laura; Martín-Biosca, Yolanda; Sagrado, Salvador; Medina-Hernández, María José

    2014-01-01

    The estimation of apparent binding constants and limit mobilities of the complexes of the enantiomers that characterize the interaction of enantiomers with chiral selectors, in this case highly sulfated β-cyclodextrin, was approached using a simple and economic electrophoretic modality, the complete filling technique (CFT) in counter-current mode. The enantiomers of eight psychoactive drugs, four antihistamines (dimethindene, promethazine, orphenadrine and terfenadine) and four antidepressants (bupropion, fluoxetine, nomifensine and viloxazine) were separated for the first time for this cyclodextrin (CD). Estimations of thermodynamic and electrophoretic enantioselectivies were also performed. Results indicate that, in general, thermodynamic enantioselectivity is the main component explaining the high resolution found, but also one case suggests that electrophoretic enantioselectivity itself is enough to obtain a satisfactory resolution. CFT results advantageous compared with conventional capillary electrophoresis (CE) and partial filling technique (PFT) for the study of the interaction between drugs and chiral selectors. It combines the use of a simple fitting model (as in CE), when the enantiomers do not exit the chiral selector plug during the separation (i.e. mobility of electroosmotic flow larger than mobility of CD), and drastic reduction of the consumption (and cost; ~99.7%) of the CD reagent (as in PFT) compared with the conventional CE. Copyright © 2013 John Wiley & Sons, Ltd.

  5. Linkage of α-cyclodextrin-terminated poly(dimethylsiloxanes by inclusion of quasi bifunctional ferrocene

    Directory of Open Access Journals (Sweden)

    Helmut Ritter

    2013-07-01

    Full Text Available We report the noncovalent linkage of terminally substituted oligo(dimethylsiloxanes bearing α-cyclodextrins (α-CD as host end groups for the cyclopentadienyl rings of ferrocene. This double complexation of unsubstituted ferrocene leads to a supramolecuar formation of the siloxane strands. Structural characterization was performed by the use of 1H NMR and IR spectroscopy and by mass spectrometry. Electron microscopy studies and dynamic light scattering measurements show a significant decrease of the derivative size after the complexation with ferrocene. In addition, further evidence for the successful complexation of the end groups was verified by the shifts of the protons in the 1H NMR spectra and in the correlation signals of the 2D ROESY NMR spectra.

  6. SYNTHESIS AND EVALUATION OF β-CYCLODEXTRIN-EPICHLOROHYDRIN INCLUSION COMPLEX AS A PHARMACEUTICAL EXCIPIENT

    Directory of Open Access Journals (Sweden)

    K. N. Poornima

    2015-05-01

    Full Text Available A water soluble Beta-cyclodextrin-epichlorohydrin complex (Beta-CDEPI was synthesized by one-step condensation polymerization. Drug- Beta-CDEPI inclusion complexes were prepared and characterized. Inclusion complexes prepared using lyophilization technique was used to formulate orodispersible tablets. Compatibility studies showed no interaction and characterization proved substantial inclusion complex formation. Drug content was found between 97-99%. In-vitro disintegration time was found to be less than 3 minutes and all the formulations showed complete drug release of 100% within 15 minutes. The formulations were found to be stable for a period of 6 months. Beta-CDEPI polymer enhances the solubility and thus effectively can be utilized to improve the aqueous solubility of poorly water soluble drugs.

  7. Effect of Cyclodextrin Complexation of Curcumin on its Solubility and Antiangiogenic and Anti-inflammatory Activity in Rat Colitis Model

    OpenAIRE

    Yadav, Vivek R.; Suresh, Sarasija; Devi, Kshama; Yadav, Seema

    2009-01-01

    The purpose of the study was to prepare and evaluate the anti-inflammatory activity of cyclodextrin (CD) complex of curcumin for the treatment of inflammatory bowel disease (IBD) in colitis-induced rat model. Inclusion complexes of curcumin were prepared by common solvent and kneading methods. These complexes were further evaluated for increase in solubility of poorly soluble curcumin. The inclusion complexes were characterized for enhancement in solubility, in vitro dissolution, surface morp...

  8. Rapid quantification of polycyclic aromatic hydrocarbons in hydroxypropyl-{beta}-cyclodextrin (HPCD) soil extracts by synchronous fluorescence spectroscopy (SFS)

    Energy Technology Data Exchange (ETDEWEB)

    Guoxiong, Hua [School of Biology and Psychology, Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Broderick, John [School of Biology and Psychology, Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Semple, Kirk T [Department of Environmental Science, Faculty of Science and Technology, University of Lancaster, Lancaster LA1 4YQ (United Kingdom); Killham, Ken [School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Singleton, Ian [School of Biology and Psychology, Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2007-07-15

    Synchronous fluorescence spectroscopy (SFS) was directly applied to rapidly quantify selected polycyclic aromatic hydrocarbons (PAHs: benzo[a]pyrene and pyrene) in aqueous hydroxypropyl-{beta}-cyclodextrin (HPCD) soil extract solutions from a variety of aged contaminated soils containing four different PAHs. The method was optimized and validated. The results show that SFS can be used to analyse benzo[a]pyrene and pyrene in HPCD based soil extracts with high sensitivity and selectivity. The linear calibration ranges were 4.0 x 10{sup -6}-1.0 x 10{sup -3} mM for benzo[a]pyrene and 6.0 x 10{sup -6}-1.2 x 10{sup -3} mM for pyrene in 10 mM HPCD aqueous solution alone. The detection limits according to the error propagation theory for benzo[a]pyrene and pyrene were 3.9 x 10{sup -6} and 5.4 x 10{sup -6} mM, respectively. A good agreement between SFS and HPLC was reached for both determinations of PAHs in HPCD alone and in soil HPCD extracts. Hence, SFS is a potential means to simplify the present non-exhaustive hydroxypropyl-{beta}-cyclodextrin (HPCD)-based extraction technique for the evaluation of PAH bioavailability in soil. - SFS can be used to rapidly quantify selected PAHs in soil extracts and to simplify the non-exhaustive HPCD-based extraction technique for the evaluation of PAH bioavailability.

  9. Rapid quantification of polycyclic aromatic hydrocarbons in hydroxypropyl-β-cyclodextrin (HPCD) soil extracts by synchronous fluorescence spectroscopy (SFS)

    International Nuclear Information System (INIS)

    Hua Guoxiong; Broderick, John; Semple, Kirk T.; Killham, Ken; Singleton, Ian

    2007-01-01

    Synchronous fluorescence spectroscopy (SFS) was directly applied to rapidly quantify selected polycyclic aromatic hydrocarbons (PAHs: benzo[a]pyrene and pyrene) in aqueous hydroxypropyl-β-cyclodextrin (HPCD) soil extract solutions from a variety of aged contaminated soils containing four different PAHs. The method was optimized and validated. The results show that SFS can be used to analyse benzo[a]pyrene and pyrene in HPCD based soil extracts with high sensitivity and selectivity. The linear calibration ranges were 4.0 x 10 -6 -1.0 x 10 -3 mM for benzo[a]pyrene and 6.0 x 10 -6 -1.2 x 10 -3 mM for pyrene in 10 mM HPCD aqueous solution alone. The detection limits according to the error propagation theory for benzo[a]pyrene and pyrene were 3.9 x 10 -6 and 5.4 x 10 -6 mM, respectively. A good agreement between SFS and HPLC was reached for both determinations of PAHs in HPCD alone and in soil HPCD extracts. Hence, SFS is a potential means to simplify the present non-exhaustive hydroxypropyl-β-cyclodextrin (HPCD)-based extraction technique for the evaluation of PAH bioavailability in soil. - SFS can be used to rapidly quantify selected PAHs in soil extracts and to simplify the non-exhaustive HPCD-based extraction technique for the evaluation of PAH bioavailability

  10. Preparation and characterization of β-cyclodextrin grafted N-maleoyl chitosan nanoparticles for drug delivery

    Directory of Open Access Journals (Sweden)

    Xinyu Hou

    2017-11-01

    Full Text Available β-cyclodextrin (CD grafted N-maleoyl chitosan (CD-g-NMCS with two different degrees of substitution (DS of N-maleoyl (DS = 21.2% and 30.5% were synthesized from maleic anhydride and chitosan bearing pendant cyclodextrin (CD-g-CS. CD-g-NMCS based nanoparticles were prepared via an ionic gelation method together with chitosan and CD-g-CS nanoparticles. The size and zeta potential of prepared CD-g-NMCS nanoparticles were 179.2~274.0 nm and 36.2~42.4 mV, respectively. In vitro stability test indicated that CD-g-NMCS nanoparticles were more stable in phosphate-buffered saline compared with chitosan nanoparticles. Moreover, a poorly water-soluble drug, ketoprofen (KTP, was selected as a model drug to study the obtained nanoparticle's potentials as drug delivery carriers. The drug loading efficiency of CD-g-NMCS20 nanoparticles were 14.8% for KTP. MTT assay showed that KTP loaded CD-g-NMCS nanoparticles were safe drug carriers. Notably, in vitro drug release studies showed that KTP was released in a sustained-release manner for the nanoparticles. The pharmacokinetic of drug loaded CD-g-NMCS20 nanoparticles were evaluated in rats after intravenous administration. The results of studies revealed that, compared with free KTP, KTP loaded CD-g-NMCS20 nanoparticles exhibited a significant increase in AUC0→24h and mean residence time by 6.6-fold and 2.9-fold, respectively. Therefore, CD-g-NMCS nanoparticles could be used as a novel promising nanoparticle-based drug delivery system for sustained release of poorly water-soluble drugs. The carboxylic acid groups of the CD-g-NMCS molecule provide convenient sites for further structural modifications including introduction of tissue- or disease- specific targeting groups.

  11. The preparation, characterization, and pharmacokinetic studies of chitosan nanoparticles loaded with paclitaxel/dimethyl-β-cyclodextrin inclusion complexes

    Directory of Open Access Journals (Sweden)

    Ye YJ

    2015-07-01

    Full Text Available Ya-Jing Ye,1 Yun Wang,1 Kai-Yan Lou,1 Yan-Zuo Chen,1 Rongjun Chen,2 Feng Gao1,3,4 1Department of Pharmaceutics, School of Pharmacy, East China University of Science and Technology, Shanghai, People’s Republic of China; 2Department of Chemical Engineering, Imperial College London, London, United Kingdom; 3Shanghai Key Laboratory of Functional Materials Chemistry, 4Shanghai Key Laboratory of New Drug Design, East China University of Science and Technology, Shanghai, People’s Republic of China Abstract: A novel biocompatible and biodegradable drug-delivery nanoparticle (NP has been developed to minimize the severe side effects of the poorly water-soluble anticancer drug paclitaxel (PTX for clinical use. PTX was loaded into the hydrophobic cavity of a hydrophilic cyclodextrin derivative, heptakis (2,6-di-O-methyl-β-cyclodextrin (DM-β-CD, using an aqueous solution-stirring method followed by lyophilization. The resulting PTX/DM-β-CD inclusion complex dramatically enhanced the solubility of PTX in water and was directly incorporated into chitosan (CS to form NPs (with a size of 323.9–407.8 nm in diameter using an ionic gelation method. The formed NPs had a zeta potential of +15.9–23.3 mV and showed high colloidal stability. With the same weight ratio of PTX to CS of 0.7, the loading efficiency of the PTX/DM-β-CD inclusion complex-loaded CS NPs was 30.3-fold higher than that of the PTX-loaded CS NPs. Moreover, it is notable that PTX was released from the DM-β-CD/CS NPs in a sustained-release manner. The pharmacokinetic studies revealed that, compared with reference formulation (Taxol®, the PTX/DM-β-CD inclusion complex-loaded CS NPs exhibited a significant increase in AUC0→24h (the area under the plasma drug concentration–time curve over the period of 24 hours and mean residence time by 2.7-fold and 1.4-fold, respectively. Therefore, the novel drug/DM-β-CD inclusion complex-loaded CS NPs have promising applications for the

  12. Facile green synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin nanocomposite in the dual acting fluorine-containing ionic liquid medium for bone substitute applications

    Energy Technology Data Exchange (ETDEWEB)

    Jegatheeswaran, S. [Advanced Green Chemistry Lab, Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi-3, Tamil Nadu (India); Selvam, S. [Laser and Sensor Application Laboratory, Pusan National University, Busan 609735 (Korea, Republic of); Sri Ramkumar, V. [Deptartment of Environmental Biotechnology, School of Environmental, Sciences, Bharathidasan University, Tiruchirappalli, Tamilnadu (India); Sundrarajan, M., E-mail: sundrarajan@yahoo.com [Advanced Green Chemistry Lab, Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi-3, Tamil Nadu (India)

    2016-05-15

    Highlights: • Fluorine based ionic liquid was highly influenced the morphological structure of nanocomposites. • These composites has been motivated controlled release of silver nanoparticles for uniform antibacterial activity. • These material has given excellent antibacterial biofilm activity and favourable cytotoxical behavior on the human osteosarcoma (MG-63) cells. • These material has been highly suitable for bone substitute appliactions. - Abstract: A novel green route has approached for the synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin composite by the assistance of fluorine-based ionic liquid. The selected [BMIM]BF{sub 4} ionic liquid for this work plays a dual role as fluoride source and templating agent. It helps to improve the crystalline structures and the shape of the composites. The crystallinity, surface morphology, topographical studies of the synthesized composite were validated. The XRD results of the composite show typical Ag reflection peaks at 38.1°, 44.2° and 63.4°. The ionic liquid assisted composite displayed the hexagonal shaped HA particles, which are surrounded by spherical nano-Ag particles and these particles are uniformly dispersed in the β-cyclodextrin matrix in both horizontal and cross sections from surface morphology observations. The Ionic liquid assisted silver doped fluor-hydroxyapatite/β-cyclodextrin composite exhibited very good antibacterial activities against Escherichia coli, Salmonella typhi, Klebsiella pneumonia and Serratia liquefaciens pathogens. The antibacterial proficiencies were established using Confocal Laser Scanning Microscopic developed biofilms images and bacterial growth curve analysis. The cytotoxicity results of the ionic liquid assisted composite analyzed by cell proliferation in vitro studies using human osteosarcoma cell line (MG-63) and this study has shown excellent biocompatibility.

  13. Facile green synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin nanocomposite in the dual acting fluorine-containing ionic liquid medium for bone substitute applications

    International Nuclear Information System (INIS)

    Jegatheeswaran, S.; Selvam, S.; Sri Ramkumar, V.; Sundrarajan, M.

    2016-01-01

    Highlights: • Fluorine based ionic liquid was highly influenced the morphological structure of nanocomposites. • These composites has been motivated controlled release of silver nanoparticles for uniform antibacterial activity. • These material has given excellent antibacterial biofilm activity and favourable cytotoxical behavior on the human osteosarcoma (MG-63) cells. • These material has been highly suitable for bone substitute appliactions. - Abstract: A novel green route has approached for the synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin composite by the assistance of fluorine-based ionic liquid. The selected [BMIM]BF_4 ionic liquid for this work plays a dual role as fluoride source and templating agent. It helps to improve the crystalline structures and the shape of the composites. The crystallinity, surface morphology, topographical studies of the synthesized composite were validated. The XRD results of the composite show typical Ag reflection peaks at 38.1°, 44.2° and 63.4°. The ionic liquid assisted composite displayed the hexagonal shaped HA particles, which are surrounded by spherical nano-Ag particles and these particles are uniformly dispersed in the β-cyclodextrin matrix in both horizontal and cross sections from surface morphology observations. The Ionic liquid assisted silver doped fluor-hydroxyapatite/β-cyclodextrin composite exhibited very good antibacterial activities against Escherichia coli, Salmonella typhi, Klebsiella pneumonia and Serratia liquefaciens pathogens. The antibacterial proficiencies were established using Confocal Laser Scanning Microscopic developed biofilms images and bacterial growth curve analysis. The cytotoxicity results of the ionic liquid assisted composite analyzed by cell proliferation in vitro studies using human osteosarcoma cell line (MG-63) and this study has shown excellent biocompatibility.

  14. Functional electrospun polystyrene nanofibers incorporating α-, β-, and γ-cyclodextrins: comparison of molecular filter performance.

    Science.gov (United States)

    Uyar, Tamer; Havelund, Rasmus; Hacaloglu, Jale; Besenbacher, Flemming; Kingshott, Peter

    2010-09-28

    Electrospinning has been used to successfully create polystyrene (PS) nanofibers containing either of three different types of cyclodextrin (CD); α-CD, β-CD, and γ-CD. These three CDs are chosen because they have different sized cavities that potentially allow for selective inclusion complex (IC) formation with molecules of different size or differences in affinity of IC formation with one type of molecule. The CD containing electrospun PS nanofibers (PS/CD) were initially characterized by scanning electron microscopy (SEM) to determine the uniformity of the fibers and their fiber diameter distributions. X-ray photoelectron spectroscopy (XPS) was used to quantitatively determine the concentration of each CD on the different fiber surfaces. Static time-of-flight secondary ion mass spectrometry (static-ToF-SIMS) showed the presence of each type of CD on the PS nanofibers by the detection of both the CD sodium adduct molecular ions (M + Na+) and lower molecular weight oxygen containing fragment ions. The comparative efficiency of the PS/CD nanofibers/nanoweb for removing phenolphthalein, a model organic compound, from solution was determined by UV-vis spectrometry, and the kinetics of phenolphthalein capture was shown to follow the trend PS/α-CD > PS/β-CD > PS/γ-CD. Direct pyrolysis mass spectrometry (DP-MS) was also performed to ascertain the relative binding strengths of the phenolphthalein for the CD cavities, and the results showed the trend in the interaction strength was β-CD > γ-CD > α-CD. Our results demonstrate that nanofibers produced by electrospinning that incorporate cyclodextrins with different sized cavities can indeed filter organic molecules and can potentially be used for filtration, purification, and/or separation processes.

  15. Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound.

    Science.gov (United States)

    Pais, Joana M; Barroca, Maria João; Marques, Maria Paula M; Almeida Paz, Filipe A; Braga, Susana S

    2017-01-01

    Fisetin is a natural antioxidant with a wide range of nutraceutical properties, including antidiabetic, neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD), a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out using elemental analysis, powder X-ray diffraction (PXRD), Raman, infrared and 13 C{ 1 H} CP-MAS NMR spectroscopies, and thermal analysis (TGA) to verify fisetin inclusion and to present a hypothetical structural arrangement for the host-guest units. The antioxidant activity of the γ-CD·fisetin inclusion compound is evaluated by the DPPH assay.

  16. Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

    Directory of Open Access Journals (Sweden)

    Joana M. Pais

    2017-10-01

    Full Text Available Fisetin is a natural antioxidant with a wide range of nutraceutical properties, including antidiabetic, neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD, a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out using elemental analysis, powder X-ray diffraction (PXRD, Raman, infrared and 13C{1H} CP-MAS NMR spectroscopies, and thermal analysis (TGA to verify fisetin inclusion and to present a hypothetical structural arrangement for the host–guest units. The antioxidant activity of the γ-CD·fisetin inclusion compound is evaluated by the DPPH assay.

  17. Enhancement and inhibition effects on the corneal permeability of timolol maleate: Polymers, cyclodextrins and chelating agents.

    Science.gov (United States)

    Rodríguez, Isabel; Vázquez, José Antonio; Pastrana, Lorenzo; Khutoryanskiy, Vitaliy V

    2017-08-30

    This study investigates how both bioadhesive polymers (chitosan, hyaluronic acid and alginate) and permeability enhancers (ethylene glycol- bis(2-aminoethylether)- N, N, N', N'- tetraacetic acid (EGTA) and hydroxypropyl-ß-cyclodextrin) influence the permeability of the anti-glaucoma drug timolol maleate through ex vivo bovine corneas. Our results showed that only the permeability enhancers alone were able to increase drug permeability, whereas the polymers significantly reduced drug permeation, and however, they increased the pre-corneal residence of timolol. Ternary systems (polymer-enhancer-drug) showed a reduced drug permeability compared to the polymers alone. Fluorescence microscopy analysis of the epithelium surface confirmed there was no evidence of epithelial disruption caused by these formulations, suggesting that polymer-enhancer interactions reduce drug solubilization and counteract the disruptive effect of the permeability enhancers on the surface of the cornea. Further mucoadhesive tests, revealed a stable interaction of chitosan and hyaluronic acid with the epithelium, while alginate showed poor mucoadhesive properties. The differences in mucoadhesion correlated with the permeability of timolol maleate observed, i.e. formulations containing mucoadhesive polymers showed lower drug permeabilities. The results of the present study indicate polymers acting as an additional barrier towards drug permeability which is even more evident in the presence of permeability enhancers like EGTA and hydroxypropyl-ß-cyclodextrin. Then, this study highlights the need to adequately select additives intended for ocular applications since interactions between them can have opposite results to what expected in terms of drug permeability. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Covalently {beta}-cyclodextrin modified single-walled carbon nanotubes: a novel artificial receptor synthesized by 'click' chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Guo Zhen; Liang Li [Nankai University, State Key Laboratory and Institute of Elemento-Organic Chemistry (China); Liang Jiajie; Ma Yanfeng; Yang Xiaoying [Nankai University, Center for Nanoscale Science and Technology and Institute of Polymer Chemistry, College of Chemistry (China); Ren Dongmei [Nankai University, State Key Laboratory and Institute of Elemento-Organic Chemistry (China); Chen Yongsheng [Nankai University, Center for Nanoscale Science and Technology and Institute of Polymer Chemistry, College of Chemistry (China); Zheng Jianyu, E-mail: jyzheng@nankai.edu.c [Nankai University, State Key Laboratory and Institute of Elemento-Organic Chemistry (China)

    2008-08-15

    Novel {beta}-cyclodextrin covalently modified single-walled carbon nanotubes have been synthesized via a 'click' coupling reaction. The product was fully characterized with Raman, FTIR, XRD, UV-Vis-NIR spectra as well as TEM and TGA measurements. The effective functionalization via 'click' coupling has set up a facile and versatile route for modular preparation of SWNTs based functional materials. The inclusion complexation behavior of this artificial receptor with quinine has been investigated in aqueous solution by fluorescence spectroscopy.

  19. Preparation and physico-chemical characterization of inclusion complexes between local anesthetics and hydroxypropyl-{beta}-cyclodextrin; Preparacao e caracterizacao fisico-quimica de complexos de inclusao entre anestesicos locais e hidroxipropil-{beta}-ciclodextrina

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Carolina Morales; Abrami, Priscila; Goncalves, Marcos Moises; Andreo Filho, Newton [Universidade de Sorocaba, SP (Brazil); Fernandes, Sergio Antonio; Paula, Eneida de [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Biologia. Dept. de Bioquimica; Fraceto, Leonardo Fernandes [UNESP, Sorocaba, SP (Brazil). Dept. de Engenharia Ambiental]. E-mail: leonardo@sorocaba.unesp.br

    2007-07-15

    S(-) Bupivacaine (S(-)BVC) and Lidocaine (LDC) are widely used local anesthetics (LA). Hydroxypropyl {beta}-cyclodextrin (HP-{beta}-CD) is used as a drug-carrier system. The aim of this work was to characterize inclusion complexes between LA and HP-{beta}-CD. The affinity constants determined at different pHs show favourable complexation. The release kinetics experiments showed that S(-)BVC and LDC changed the released profiles in the presence of HP-{beta}-CD. Nuclear magnetic resonance experiments gave information about the interaction between LA and the cyclodextrin cavity. This study focused on the physicochemical characterization of drug-delivery formulations that come out as potentially new therapeutic options for pain treatment. (author)

  20. Cholesterol Removal from Whole Egg by Crosslinked β-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    H. J. Jeong

    2014-04-01

    Full Text Available This study was carried out to optimize cholesterol removal in whole egg using crosslinked β-cyclodextrin (β-CD and to recycle the β-CD. Various factors for optimizing conditions were concentration of the β-CD, mixing temperature, mixing time, mixing speed and centrifugal speed. In the result of this study, the optimum conditions of cholesterol removal were 25% crosslinked β-CD, 40°C mixing temperature, 30 min mixing time, 1,200 rpm mixing speed and 2,810×g centrifugal speed. The recycling was repeated five times. The cholesterol removal was 92.76% when treated with the optimum conditions. After determining the optimum conditions, the recyclable yields of the crosslinked β-CD ranged from 86.66% to 87.60% in the recycling and the percentage of cholesterol removal was over 80% until third recycling. However, the cholesterol removal efficiency was decreased when the number of repeated recycling was increased. Based on the result of this study, it was concluded that the crosslinked β-CD was efficient for cholesterol removal in whole egg, and recycling is possible for only limited repeating times due to the interaction of the β-CD and egg protein.

  1. Compatibility of hydroxypropyl-β-cyclodextrin with algal toxicity bioassays

    International Nuclear Information System (INIS)

    Fai, Patricia Bi; Grant, Alastair; Reid, Brian J.

    2009-01-01

    Numerous reports have indicated that hydrophobic organic compound bioaccessibility in sediment and soil can be determined by extraction using aqueous hydroxypropyl-β-cyclodextrin (HPCD) solutions. This study establishes the compatibility of HPCD with Selenastrum capricornutum and assesses whether its presence influences the toxicity of reference toxicants. Algal growth inhibition (72 h) showed no significant (P > 0.05) difference at HPCD concentrations up to and including 20 mM. HPCD presence did not influence the toxicity of the inorganic reference toxicant (ZnSO 4 ), with IC50 values of 0.82 μM and 0.85 μM, in the presence and absence of HPCD (20 mM), respectively. However, HPCD presence (20 mM) reduced the toxicity of 2,4-dichlorophenol and the herbicides diuron and isoproturon. These reductions were attributed to inclusion complex formation between the toxicants and the HPCD cavity. Liberation of complexed toxicants, by sample manipulation prior to toxicity assessment, is proposed to provide a sensitive, high throughput, bioassay that reflects compound bioaccessibility. - Compatibility of the biomimetic HPCD extraction method with algal cell growth inhibition bioassays to assess toxicity of reference toxicants and environmental relevant herbicides

  2. Compatibility of hydroxypropyl-{beta}-cyclodextrin with algal toxicity bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Fai, Patricia Bi; Grant, Alastair [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Reid, Brian J. [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom)], E-mail: b.reid@uea.ac.uk

    2009-01-15

    Numerous reports have indicated that hydrophobic organic compound bioaccessibility in sediment and soil can be determined by extraction using aqueous hydroxypropyl-{beta}-cyclodextrin (HPCD) solutions. This study establishes the compatibility of HPCD with Selenastrum capricornutum and assesses whether its presence influences the toxicity of reference toxicants. Algal growth inhibition (72 h) showed no significant (P > 0.05) difference at HPCD concentrations up to and including 20 mM. HPCD presence did not influence the toxicity of the inorganic reference toxicant (ZnSO{sub 4}), with IC50 values of 0.82 {mu}M and 0.85 {mu}M, in the presence and absence of HPCD (20 mM), respectively. However, HPCD presence (20 mM) reduced the toxicity of 2,4-dichlorophenol and the herbicides diuron and isoproturon. These reductions were attributed to inclusion complex formation between the toxicants and the HPCD cavity. Liberation of complexed toxicants, by sample manipulation prior to toxicity assessment, is proposed to provide a sensitive, high throughput, bioassay that reflects compound bioaccessibility. - Compatibility of the biomimetic HPCD extraction method with algal cell growth inhibition bioassays to assess toxicity of reference toxicants and environmental relevant herbicides.

  3. Sorption of Aromatic Compounds with Copolymer Sorbent Materials Containing β-Cyclodextrin.

    Science.gov (United States)

    Wilson, Lee D; Mohamed, Mohamed H; Berhaut, Christopher L

    2011-08-29

    Urethane copolymer sorbent materials that incorporate β-cyclodextrin (CD) have been prepared and their sorption properties with chlorinated aromatic compounds (i.e., pentachlorophenol, 2,4-dichlorophenol and 2,4-dichlorophenoxy acetic acid) have been evaluated. The sorption properties of granular activated carbon (GAC) were similarly compared in aqueous solution at variable pH conditions. The sorbents displayed variable BET surface areas as follows: MDI-X copolymers (granular activated carbon (GAC ~10³ m²/g). The sorption capacities for the copolymers sorbents are listed in descending order, as follows: GAC > CDI-3 copolymer ≈ MDI-3 copolymer. The sorption capacity for the aromatic adsorbates with each sorbent are listed in descending order, as follows: 2,4-dichlorophenol > 2,4-dichlorophenoxy acetic acid > pentachlorophenol. In general, the differences in the sorption properties of the copolymer sorbents with the chlorinated organics were related to the following factors: (i) surface area of the sorbent; (ii) CD content and accessibility; and (iii) and the chemical nature of the sorbent material.

  4. Discriminative sensing of DOPA enantiomers by cyclodextrin anchored graphene nanohybrids.

    Science.gov (United States)

    Ates, Salih; Zor, Erhan; Akin, Ilker; Bingol, Haluk; Alpaydin, Sabri; Akgemci, Emine G

    2017-06-01

    Discriminative sensing of chiral species with a convenient and robust system is a challenge in chemistry, pharmaceutics and particularly in biomedical science. Advanced nanohybrid materials for discrimination of these biologically active molecules can be developed by combination of individual obvious advantages of different molecular scaffolds. Herein, we report on the comparison of the performance of cyclodextrin functionalized graphene derivatives (x-CD/rGO, x: α-, β-, γ-) for discrimination of DOPA enantiomers. Within this respect, electrochemical measurements were conducted and the experimental results were compared to molecular docking method. Thanks to cavity size of γ-CD and the unique properties of graphene, rGO/γ-CD nanohybrid is capable of selective recognition of DOPA enantiomers. Limit of detection (LOD) value and sensitivity were determined as 15.9 μM and 0.2525 μA μM -1 for D-DOPA, and 14.9 μM and 0.6894 μA μM -1 for L-DOPA. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Enhancement of solubility of albendazole by complexation with β-cyclodextrin

    International Nuclear Information System (INIS)

    Moriwaki, C.; Costa, G.L.; Ferracini, C.N.; Matioli, G.; Moraes, F.F. de; Zanin, G.M.; Pineda, E.A.G.

    2008-01-01

    A high dosage of albendazole (ABZ) is required for treating systemic helminth infections because of its low solubility. Aiming at increasing ABZ solubility, complexation with beta-cyclodextrin (β-CD) using aqueous and acetic acid solutions as ABZ solubiliser was studied. In aqueous β-CD, complexation increased solubility 53.4 times, giving a complex equilibrium constant of 1266 L mol -1 with a maximum ABZ concentration of 276 μmol L -1 for 16.3 mmol L -1 β-CD. For complexation in 1.05 mol L -1 acetic acid, UV absorbance spectra and 1 H-NMR analysis confirmed complex formation. The UV absorbance of ABZ/acid acetic/β-CD solutions was modeled by the formation of two complexes with molar ratios 1:1 and 1:2 ABZ:β-CD. When neutralized with NaOH these solutions did not form precipitates only for the ABZ:β-CD molar ratios of 1:8 and 1:10, showing that ABZ solubility could be increased 306 times. Results show that high β-CD molar ratios hold ABZ in solution by complexation enhanced by the acetate anion. (author)

  6. Structural characterization of inclusion complex of hesperidin methyl chalcone and hydroxypropyl-beta-cyclodextrin

    International Nuclear Information System (INIS)

    Li, Y.; Li, F.; Chen, X.; Shen, W.

    2016-01-01

    Hesperidin methyl chalcone (HMC) was a semisynthetic derivative of hesperidin, which owned antiviral and antimicrobial activities. Owing these properties, it can be applied in pharmaceutical industry. However low stability had become a barrier to its application. In order to overcome this problem, an inclusion complex of hesperidin methyl chalcone and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) were prepared by freeze-drying, using some analytical techniques to characterize the inclusion complex, including ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The results of these analytical techniques indicated that the hesperidin methyl chalcone has been dispersed completely in the HP-beta-CD without a new compound formed, but entrapped inside the cavity of HP-beta-CD. (author)

  7. A novel electrochemical immunosensor using β-cyclodextrins functionalized silver supported adamantine-modified glucose oxidase as labels for ultrasensitive detection of alpha-fetoprotein.

    Science.gov (United States)

    Gao, Jian; Ma, Hongmin; Lv, Xiaohui; Yan, Tao; Li, Na; Cao, Wei; Wei, Qin

    2015-09-17

    In this work, a novel sandwich-type electrochemical immunosensor based on host-guest interaction was fabricated for the detection of alpha-fetoprotein (AFP). Due to the large specific surface area of multiwalled carbon nanotubes and the unique supramolecular recognition ability of β-cyclodextrins, ferrocenecarboxylic acid (Fc) was incorporated into this sensor platform by host-guest interaction to generate an electrochemical signal. And β-cyclodextrins functionalized silver supported adamantine-modified glucose oxidase (GOD-CD-Ag), was used as a label to improve the analytical performance of the immunosensor by the dual amplification strategy. The obtained GOD-CD-Ag conjugates could convert glucose into gluconic acid with the formation of hydrogen peroxide (H2O2). And then silver nanoparticles could in situ catalyze the reduction of the generated H2O2, dramatically improving the oxidation reaction of Fc. The developed immunosensor shows a wide linear calibration range from 0.001 to 5.0 ng/mL with a low detection limit (0.2 pg/mL) for the detection of AFP. The method, with ideal reproducibility and selectivity, has a wide application prospect in clinical research. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. A simple conductometric method for trace level determination of brilliant green in water based on β-cyclodextrin and silver nitrate and determination of their thermodynamic parameters

    Directory of Open Access Journals (Sweden)

    Roya Mohammad Zadeh Kakhki

    2014-12-01

    Full Text Available A gravimetric and complexometric titration method based on conductometric technique is presented for the quantitative determination of brilliant green (BG in water. The equilibrium constants and the thermodynamic parameters for the complex formation of β-cyclodextrin (β-CD with brilliant green (BG and precipitation of silver nitrate with BG have been determined by conductivity measurements in water. The results suggest that stable 1:1 complex is formed between BG and β-cyclodextrin and the thermodynamic parameters (ΔHc°,ΔSc° for this complexation reaction have been determined from temperature dependence of the stability constant using the van’t Hoff plots. Based on the obtained results, the conductometric method for the determination of BG in the presence of β-CD at 25 °C was developed in the range of 10−8–10−3 molL−1 and with AgNO3 is 10−3–10−5 molL−1.

  9. Preparation, characterization, and thermal stability of β-cyclodextrin/soybean lecithin inclusion complex.

    Science.gov (United States)

    Wang, Xinge; Luo, Zhigang; Xiao, Zhigang

    2014-01-30

    β-Cyclodextrin (β-CD), which is widely used to increase the stability, solubility, and bioavailability of guests, can form host-guest inclusion complexes with a wide variety of organic molecules. In this study the β-CD/soybean lecithin inclusion complex was prepared. The effect of reaction parameters such as reaction temperature, reaction time and the molar ratio of β-CD/soybean lecithin on inclusion ratio were studied. The inclusion ratio of the product prepared under the optimal conditions of β-CD/soybean lecithin molar ratio 2:1, reaction temperature 60°C reaction time 2h was 40.2%. The results of UV-vis, DSC, XRD and FT-IR spectrum indicated the formation of inclusion complex. The thermal stability experiment indicated that the thermal stability of soybean lecithin in inclusion complex was significantly improved compared with free soybean lecithin. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Direct site-directed photocoupling of proteins onto surfaces coated with β-cyclodextrins

    DEFF Research Database (Denmark)

    Städe, Lars W; Wimmer, Reinhard; Stensballe, Allan

    2010-01-01

    . Insertion of pBpa was verified by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectroscopy. A molecular dynamic simulation, with water as solvent, showed high solvent accessibility of the pBpa benzophenone group in N27pBpa-cutinase mutant. The formation of an inclusion......A method called Dock'n'Flash was developed to offer site-specific capture and direct UVA-induced photocoupling of recombinant proteins. The method involves the tagging of recombinant proteins with photoreactive p-benzoyl-L-phenylalanine (pBpa) by genetic engineering. The photoreactive pBpa tag...... is used for affinity capture of the recombinant protein by beta-cyclodextrin (beta-CD), which provides hydrogen atoms to be abstracted in the photocoupling process. To exemplify the method, a recombinant, folded, and active N27pBpa mutant of cutinase from Fusarium solani pisi was produced in E. coli...

  11. Effect of O-methyl-.beta.-cyclodextrin-modified magnetic nanoparticles on the uptake and extracellular level of L-glutamate in brain nerve terminals

    Czech Academy of Sciences Publication Activity Database

    Horák, Daniel; Beneš, Milan J.; Procházková, Zuzana; Trchová, Miroslava; Borysov, A.; Pastukhov, A.; Paliienko, K.; Borisova, T.

    2017-01-01

    Roč. 149, 1 January (2017), s. 64-71 ISSN 0927-7765 R&D Projects: GA ČR(CZ) GC16-01128J; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61389013 Keywords : glutamate * cholesterol * O-methyl-beta-cyclodextrin Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.887, year: 2016

  12. Host-Guest Inclusion Complexes between Amlodipine Enantiomers in the Biphasic Recognition Chiral Extraction System using Tartaric Acid and β-Cyclodextrin Derivatives as Positive Confirmation by using their Enantioselective Extraction.

    Science.gov (United States)

    Al Azzam, Khaldun M; Abdallah, Hassan H; Halim, Hairul N Abdul; Ahmad, Maizatul Akmam; Shaibah, Hassan

    2015-01-01

    The current work reports an extended theoretical study from our previous experimental work for the enantioselective extraction of amlodipine enantiomers in a biphasic recognition chiral extraction system (BRCES) consisting of hydrophobic D-diisopropyl tartrate dissolved in organic phase (n-decanol) and hydrophilic hydroxypropyl-β-cyclodextrin (HP-β-CD) in aqueous phase (acetate buffer) which preferentially recognize the R-enantiomer and S-enantiomer, respectively. The calculations were simulated using a semi-empirical PM3 method as a part of the Gaussian09 software package and were used to optimize the structures of the hosts, guests, and host-guest complexes in the gas phase without any restrictions. It was found that HP-β-CD has the strongest recognition ability among the three β-CD derivatives studied, namely HP-β-CD, hydroxyethyl-β-cyclodextrin (HE-β-CD), and methylated-β-cyclodextrin (Me-β-CD), due to the large interaction energies (Ecomp = -14.3025 kcal/ mol), while D-diisopropyl tartrate has the strongest ability among the four tartaric acid derivatives studied namely; L-diisopropyl tartrate, D-diisopropyl tartrate, L-diethyl tartrate, and D-diethyl tartrate (Ecomp = -5.9964 kcal/ mol). The computational calculations for the enantioselective partitioning of amlodipine enantiomers rationalized the reasons for the different behaviors for this extraction. The present theoretical results may be informative to scientists who are devoting themselves to developing models for their experimental parts or for enhancing the hydrophobic drug solubility in drug delivery systems.

  13. Host-Guest Inclusion Complexes between Amlodipine Enantiomers in the Biphasic Recognition Chiral Extraction System using Tartaric Acid and β-Cyclodextrin Derivatives as Positive Confirmation by using their Enantioselective Extraction

    Science.gov (United States)

    Al Azzam, Khaldun M.; Abdallah, Hassan H.; Halim, Hairul N. Abdul; Ahmad, Maizatul Akmam; Shaibah, Hassan

    2015-01-01

    The current work reports an extended theoretical study from our previous experimental work for the enantioselective extraction of amlodipine enantiomers in a biphasic recognition chiral extraction system (BRCES) consisting of hydrophobic D-diisopropyl tartrate dissolved in organic phase (n-decanol) and hydrophilic hydroxypropyl-β-cyclodextrin (HP-β-CD) in aqueous phase (acetate buffer) which preferentially recognize the R-enantiomer and S-enantiomer, respectively. The calculations were simulated using a semi-empirical PM3 method as a part of the Gaussian09 software package and were used to optimize the structures of the hosts, guests, and host-guest complexes in the gas phase without any restrictions. It was found that HP-β-CD has the strongest recognition ability among the three β-CD derivatives studied, namely HP-β-CD, hydroxyethyl-β-cyclodextrin (HE-β-CD), and methylated-β-cyclodextrin (Me-β-CD), due to the large interaction energies (Ecomp = −14.3025 kcal/ mol), while D-diisopropyl tartrate has the strongest ability among the four tartaric acid derivatives studied namely; L-diisopropyl tartrate, D-diisopropyl tartrate, L-diethyl tartrate, and D-diethyl tartrate (Ecomp = −5.9964 kcal/ mol). The computational calculations for the enantioselective partitioning of amlodipine enantiomers rationalized the reasons for the different behaviors for this extraction. The present theoretical results may be informative to scientists who are devoting themselves to developing models for their experimental parts or for enhancing the hydrophobic drug solubility in drug delivery systems. PMID:26839848

  14. Synthesis, characterization, and evaluation of pluronic-based β-cyclodextrin polyrotaxanes for mobilization of accumulated cholesterol from Niemann-Pick type C fibroblasts.

    Science.gov (United States)

    Collins, Christopher J; McCauliff, Leslie A; Hyun, Seok-Hee; Zhang, Zhaorui; Paul, Lake N; Kulkarni, Aditya; Zick, Klaus; Wirth, Mary; Storch, Judith; Thompson, David H

    2013-05-14

    Several lines of evidence suggest that β-cyclodextrin (β-CD) derivatives initiate the efflux of accumulated, unesterified cholesterol from the late endosomal/lysosomal compartment in Niemann Pick C (NPC) disease models. Unfortunately, repeated injections or continuous infusions of current β-CD therapies are required to sustain suppression of symptoms and prolong life. In an effort to make CD treatment a more viable option by boosting efficacy and improving pharmacokinetics, a library of Pluronic surfactant-based β-CD polyrotaxanes has been developed using biocompatible poly(ethylene glycol) (PEG)-polypropylene glycol (PPG)-PEG triblock copolymers. These compounds carry multiple copies of β-CD as shown by (1)H NMR, 2D nuclear Overhouser effect spectroscopy, gel permeation chromatography/multiangle light scattering, analytical ultracentrifugation analysis, matrix assisted laser desorption/ionization mass spectrometry, and diffusion-ordered spectroscopy. Analyses of free β-cyclodextrin contamination in the compounds were made by reverse phase high pressure liquid chromatography and hydrophilic interaction liquid chromatography. Dethreading kinetics were studied by reverse phase high pressure liquid chromatography, UV/vis, and (1)H NMR analysis. Filipin staining studies using npc2(-/-) fibroblasts show significant reversal of cholesterol accumulation after treatment with polyrotaxane compounds. The rate and efficacy of reversal is similar to that achieved by equivalent amounts of monomeric β-CD alone.

  15. Enantioseparation of linear and cyclic chiral bis(phenethyl)amines by means of cyclodextrin-modified capillary electrophoresis.

    Science.gov (United States)

    Wedig, M; Thunhorst, M; Laug, S; Decker, M; Lehmann, J; Holzgrabe, U

    2001-09-01

    For two years drugs introduced to the market have had- to be enantiomerically pure. Rapid and cheap methods of high reproducibility must, therefore, be available for evaluation of enantiomeric purity. Within the framework of a larger project dealing with chiral recognition of phenethylamines by means of native and derivatized cyclodextrins it was intended to find capillary electrophoresis methods suitable for separation of the enantiomers of chiral bis(phenethyl)amines and their corresponding cyclic analogues, within 10 min, using small amounts of a chiral selector, to save time and money. Heptakis(2,3-O-diacetyl-6-sulfato)beta-CD was found to be the most promising candidate most often fulfilling these requirements.

  16. Characterization of the inclusion complex ropivacaine: {beta}-cyclodextrin; Caracterizacao do complexo de inclusso ropivacaina: {beta}-ciclodextrina

    Energy Technology Data Exchange (ETDEWEB)

    Fraceto, Leonardo Fernandes [Universidade Estadual Paulista Julio de Mesquita Filho, Sorocaba, SP (Brazil). Dept. de Engenharia Ambiental]. E-mail: leonardo@sorocaba.unesp.br; Goncalves, Marcos Moises [Universidade de Sorocaba, SP (Brazil); Moraes, Carolina Morales; Araujo, Daniele Ribeiro de; Zanella, Luciana; Paula, Eneida de [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Biologia. Dept. de Bioquimica; Pertinhez, Thelma de Aguiar [Universidade de Parma (Italy). Dept. de Medicina Experimental

    2007-09-15

    Ropivacaine (RVC) is a widely used local anesthetic. The complexation of RVC with {beta}-cyclodextrin ({beta}-CD) is of great interest for the development of more efficient local anesthetic formulations. The present work focuses on the characterization of the RVC:{beta}-CD complex by nuclear magnetic resonance (NMR). The stoichiometry of the complex is 1:2 RVC:{beta}-CD. DOSY-NMR shows that the association constant is 55.5 M{sup -1}. Longitudinal relaxation time results show that RVC changes its mobility in the presence of {beta}-CD. This study is focused on the physicochemical characterization of inclusion complexes that are potentials options for pain treatment. (author)

  17. Aplicação de ciclodextrinas em processos têxteis Application of cyclodextrins in textile processes

    Directory of Open Access Journals (Sweden)

    Jürgen Andreaus

    2010-01-01

    Full Text Available Cyclodextrins (CDs are water soluble cyclic sugars with a hydrophobic nanometric cavity that permits the formation of host/guest inclusion complexes with a large variety of molecules, alternating their physical-chemical properties. In the present review CD research related to the processing of textiles is revised and discussed. CDs may function as encapsulating, dispersing and levelling agents in the dyeing and washing of textiles. Furthermore they may be anchored to polymers and textile fibers in order to impart special properties such as odor reduction, UV protection or for the controlled release of perfumes, aromas, mosquito repellents or substances with therapeutical effects.

  18. Thermodynamic investigation of the interaction between cyclodextrins and preservatives - Application and verification in a mathematical model to determine the needed preservative surplus in aqueous cyclodextrin formulations.

    Science.gov (United States)

    Holm, René; Olesen, Niels Erik; Alexandersen, Signe Dalgaard; Dahlgaard, Birgitte N; Westh, Peter; Mu, Huiling

    2016-05-25

    Preservatives are inactivated when added to conserve aqueous cyclodextrin (CD) formulations due to complex formation between CDs and the preservative. To maintain the desired conservation effect the preservative needs to be added in apparent surplus to account for this inactivation. The purpose of the present work was to establish a mathematical model, which defines this surplus based upon knowledge of stability constants and the minimal concentration of preservation to inhibit bacterial growth. The stability constants of benzoic acid, methyl- and propyl-paraben with different frequently used βCDs were determined by isothermal titration calorimetry. Based upon this knowledge mathematical models were constructed to account for the equilibrium systems and to calculate the required concentration of the preservations, which was evaluated experimentally based upon the USP/Ph. Eur./JP monograph. The mathematical calculations were able to predict the needed concentration of preservation in the presence of CDs; it clearly demonstrated the usefulness of including all underlying chemical equilibria in a mathematical model, such that the formulation design can be based on quantitative arguments. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Inclusion of fluorophores in cyclodextrins: a closer look at the fluorometric determination of association constants by linear and nonlinear fitting procedures

    Science.gov (United States)

    Hutterer, Rudi

    2018-01-01

    The author discusses methods for the fluorometric determination of affinity constants by linear and nonlinear fitting methods. This is outlined in particular for the interaction between cyclodextrins and several anesthetic drugs including benzocaine. Special emphasis is given to the limitations of certain fits, and the impact of such studies on enzyme-substrate interactions are demonstrated. Both the experimental part and methods of analysis are well suited for students in an advanced lab.

  20. The Synthesis of N-Acetyllactosamine Functionalized Dendrimers, and the Functionalization of Silica Surfaces Using Tunable Dendrons and beta-Cyclodextrins

    Science.gov (United States)

    Ennist, Jessica Helen

    Galectin-3 is beta-galactoside binding protein which is found in many healthy cells. In cancer, the galectin-3/tumor-associated Thomsen-Friedenreich antigen (TF antigen) interaction has been implicated in heterotypic and homotypic cellular adhesion and apoptotic signaling pathways. However, a stronger mechanistic understanding of the role of galectin-3 in these processes is needed. N-acetyllactosamine (LacNAc) is a non-native ligand for galectin-3 which binds with comparable affinity to the TF antigen and therefore an important ligand to study galectin-3 mediated processes. To study galectin-3 mediated homotypic cellular aggregation, four generations of polyamidoamine (PAMAM) dendrimers were functionalized with N-acetyllactosamine using a four-step chemoenzymatic route. The enzymatic step controlled the regiochemistry of the galactose addition to N-acetylglucosamine functionalized dendrimers using a recombinant beta-1,4-Galactosyltransferase-/UDP-4'-Gal Epimerase Fusion Protein (lgtB-galE). Homotypic cellular aggregation, which is promoted by the presence of galectin-3 as it binds to glycosides at the cell surface, was studied using HT-1080 fibrosarcoma, A549 lung, and DU-145 prostate cancer cell lines. In the presence of small LacNAc functionalized PAMAM dendrimers, galectin-3 induced cancer cellular aggregation was inhibited. However, the larger glycodendrimers induced homotypic cellular aggregation. Additionally, novel poly(aryl ether) dendronized silica surfaces designed for reversible adsorbtion of targeted analytes were synthesized, and characterization using X-ray Photoelectron Spectroscopy (XPS) was performed. Using a Cu(I) mediated cycloaddition "click" reaction, beta-cyclodextrin was appended to dendronized surfaces via triazole formation and also to a non-dendronized surface for comparison purposes. First generation G(1) dendrons have more than 6 times greater capacity to adsorb targeted analytes than slides functionalized with monomeric beta-cyclodextrin