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Yujun Feng - One of the best experts on this subject based on the ideXlab platform.
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switching wormlike micelles of selenium containing surfactant using redox reaction
Soft Matter, 2015Co-Authors: Yongmin Zhang, Yun Fang, Weiwei Kong, Cheng Wang, Yujun Feng, Zhirong Qin, Xuefeng LiuAbstract:A novel redox-switchable wormlike Micellar System was developed based on a mixture of selenium-containing zwitterionic surfactant and commercially available anionic surfactant sodium dodecyl sulfate, which reversibly and quickly responds to H2O2 and vitamin C, and shows circulatory gel/sol transition, reflecting changes in aggregate morphology from entangled worms to vesicles.
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single component wormlike Micellar System formed by a carboxylbetaine surfactant with c22 saturated tail
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013Co-Authors: Yongmin Zhang, Yujun Feng, Yeyuan Luo, Yuejiao Wang, Jichao ZhangAbstract:Abstract C22-tailed surfactants have aroused considerable attention due to their strong tendency to self-assemble into wormlike micelles, but most of these amphiphilies were prepared from erucic acid whose mono-unsaturated hydrophobic tail is readily degraded at high temperature. Here we report for the first time the wormlike micelles formed from a sole carboxylbetaine surfactant with a saturated C22-tail, docosyl dimethyl carboxylbetaine (DDCB), and examined its aqueous solution properties through UV–vis spectroscopy, surface tension, rheology and cryo-TEM observation. Above its Krafft temperature (59.5 °C) and overlapping concentration (∼0.68 mM), DDCB aqueous solution displays unusually strong viscoelasticity without needing any specialized hydrotropes that are normally necessary in conventional wormlike Micellar Systems. Cryo-TEM observation confirmed the coexistence of wormlike micelles and viscles, in good agreement with the prediction from “packing parameter” theory. Compared with its unsaturated counterparts, DDCB worms show lower overlapping concentration, longer breaking time, better stability at high temperature and ease of preparation due to the “single-component” character.
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co2 switchable wormlike micelles
Chemical Communications, 2010Co-Authors: Zonglin Chu, Yujun FengAbstract:A wormlike Micellar System that undergoes a fully reversible, repeatable “sol–gel” transition upon alternative treatment with CO2 and N2 has been developed based on a C18-tailed polyamine surfactant.
Marjaliisa Riekkola - One of the best experts on this subject based on the ideXlab platform.
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mixed micelles of sodium dodecyl sulfate and sodium cholate Micellar electrokinetic capillary chromatography and nuclear magnetic resonance spectroscopy
Analytical Chemistry, 1997Co-Authors: Susanne K Wiedmer, Marjaliisa Riekkola, Magnus Nyden, Olle SodermanAbstract:Physicochemical properties of a mixed Micellar System of sodium dodecyl sulfate (SDS) and sodium cholate (SC) were investigated. The micelle−micelle and micelle−buffer interactions in an SDS/SC/[(1,1-dimethyl-2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid buffer System for separations by Micellar electrokinetic capillary chromatography (MEKC) were studied by capillary electrophoresis (CE) and nuclear magnetic resonance (NMR) techniques. A mixed Micellar System of SDS and SC can effectively be used for the separation by MEKC of highly hydrophobic compounds like corticosteroids. Marked differences in distribution coefficients of the corticosteroids were observed when the Micellar phase was changed from the highly hydrophobic SDS to the less hydrophobic SC. Measurements of critical micelle concentration were made by CE and conductometric titration. The mixed Micellar System was further characterized by NMR methods. NMR-based self-diffusion measurements and NMR relaxation measurements showed that SC affe...
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determination of serum corticosteroids by mixed Micellar electrokinetic capillary chromatography with sodium dodecyl sulfate and sodium cholate
Electrophoresis, 1997Co-Authors: Susanne K Wiedmer, Heli Siren, Marjaliisa RiekkolaAbstract:The application of mixed Micellar electrokinetic capillary electrochromatography to the determination of the corticosteroid hormones cortisone, cortisol (hydrocortisone), and dexamethasone in serum samples is demonstrated. The serum samples were enzymatically hydrolyzed, precipitated, solid-phase extracted, and analyzed by capillary electrophoresis. A Micellar System of sodium dodecyl sulfate and sodium cholate buffered with an organic compound provided the electrolyte solution. Spiked blank serum samples were used for the linearity testing and limits of detection and quantitation were measured. Patient samples were analyzed and the concentrations of cortisol and cortisone were measured. The method, which was fast and easy to perform, was confirmed to be useful for the determination of corticosteroids in serum.
Susanne K Wiedmer - One of the best experts on this subject based on the ideXlab platform.
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mixed micelles of sodium dodecyl sulfate and sodium cholate Micellar electrokinetic capillary chromatography and nuclear magnetic resonance spectroscopy
Analytical Chemistry, 1997Co-Authors: Susanne K Wiedmer, Marjaliisa Riekkola, Magnus Nyden, Olle SodermanAbstract:Physicochemical properties of a mixed Micellar System of sodium dodecyl sulfate (SDS) and sodium cholate (SC) were investigated. The micelle−micelle and micelle−buffer interactions in an SDS/SC/[(1,1-dimethyl-2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid buffer System for separations by Micellar electrokinetic capillary chromatography (MEKC) were studied by capillary electrophoresis (CE) and nuclear magnetic resonance (NMR) techniques. A mixed Micellar System of SDS and SC can effectively be used for the separation by MEKC of highly hydrophobic compounds like corticosteroids. Marked differences in distribution coefficients of the corticosteroids were observed when the Micellar phase was changed from the highly hydrophobic SDS to the less hydrophobic SC. Measurements of critical micelle concentration were made by CE and conductometric titration. The mixed Micellar System was further characterized by NMR methods. NMR-based self-diffusion measurements and NMR relaxation measurements showed that SC affe...
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determination of serum corticosteroids by mixed Micellar electrokinetic capillary chromatography with sodium dodecyl sulfate and sodium cholate
Electrophoresis, 1997Co-Authors: Susanne K Wiedmer, Heli Siren, Marjaliisa RiekkolaAbstract:The application of mixed Micellar electrokinetic capillary electrochromatography to the determination of the corticosteroid hormones cortisone, cortisol (hydrocortisone), and dexamethasone in serum samples is demonstrated. The serum samples were enzymatically hydrolyzed, precipitated, solid-phase extracted, and analyzed by capillary electrophoresis. A Micellar System of sodium dodecyl sulfate and sodium cholate buffered with an organic compound provided the electrolyte solution. Spiked blank serum samples were used for the linearity testing and limits of detection and quantitation were measured. Patient samples were analyzed and the concentrations of cortisol and cortisone were measured. The method, which was fast and easy to perform, was confirmed to be useful for the determination of corticosteroids in serum.
Shirui Mao - One of the best experts on this subject based on the ideXlab platform.
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designing Micellar nanocarriers with improved drug loading and stability based on solubility parameter
Molecular Pharmaceutics, 2015Co-Authors: Ye Tian, Chenjun Shi, Yujiao Sun, Chengyun Zhu, Changquan Calvin Sun, Shirui MaoAbstract:The objective of this study is to demonstrate the feasibility of using solubility parameter as guidance for the design and identification of a stable Micellar System with a high drug loading capacity for oral drug delivery. Using hydroxycamptothecin (HCPT) as a model drug, the effect of three hydrophobic blocks (fatty glycerides) grafted onto chitosan on the drug loading and stability of HCPT-loaded Micellar nanoparticles formed by pH precipitation method were studied Systematically. The Flory-Huggins interaction parameter (χFH) calculated by the group contribution method (GCM) and molecular dynamics simulation (MDS) was used to assess the compatibility between HCPT and the copolymers. The predicted order of compatibility between three chitosan derivatives and HCPT was verified experimentally. A high drug loading and remarkably stable Micellar System for oral administration based on succinylated glycerol monooleate-chitosan was discovered in this study. Our study suggests that the miscibility between drug and copolymer is crucial to drug loading and stability of the Micellar System. Thus, the calculation of χFH using GCM and MDS methods is useful for guiding the design or screening of a suitable copolymer for preparing drug-loaded Micellar nanocarrier Systems.
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designing Micellar nanocarriers with improved drug loading and stability based on solubility parameter
Molecular Pharmaceutics, 2015Co-Authors: Ye Tian, Chenjun Shi, Yujiao Sun, Chengyun Zhu, Changquan Calvin Sun, Shirui MaoAbstract:The objective of this study is to demonstrate the feasibility of using solubility parameter as guidance for the design and identification of a stable Micellar System with a high drug loading capacity for oral drug delivery. Using hydroxycamptothecin (HCPT) as a model drug, the effect of three hydrophobic blocks (fatty glycerides) grafted onto chitosan on the drug loading and stability of HCPT-loaded Micellar nanoparticles formed by pH precipitation method were studied Systematically. The Flory–Huggins interaction parameter (χFH) calculated by the group contribution method (GCM) and molecular dynamics simulation (MDS) was used to assess the compatibility between HCPT and the copolymers. The predicted order of compatibility between three chitosan derivatives and HCPT was verified experimentally. A high drug loading and remarkably stable Micellar System for oral administration based on succinylated glycerol monooleate-chitosan was discovered in this study. Our study suggests that the miscibility between drug...
Zhuobin Yuan - One of the best experts on this subject based on the ideXlab platform.
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determination of hydroxyanthraquinoids in rhubarb by cyclodextrin modified Micellar electrokinetic chromatography using a mixed Micellar System of sodium dodecyl sulfate and sodium cholate
Journal of Pharmaceutical and Biomedical Analysis, 2003Co-Authors: Xiaoyu Shang, Zhuobin YuanAbstract:A cyclodextrin-modified Micellar electrokinetic chromatographic (CD-MEKC) method was established to determine five hydroxyanthraquinoids in Rhubarb. The five components were successfully separated by using the mixed Micellar System consisting of 20 mmol/l sodium dodecyl sulfate (SDS) and 20 mmol/l sodium cholate (SC) with 10 mmol/l β-cyclodextrin in phosphate buffer (pH 10.4). The separation was optimized by adjusting buffer pH, concentrations of β-cyclodextrin and SC and applied voltage. The proposed method was validated and applied to the determination of two commercial Rhubarb samples. The results obtained were satisfactory.
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determination of six components in rhubarb by cyclodextrin modified Micellar electrokinetic chromatography using a mixed Micellar System of sodium cholate and sodium taurocholate
Analytica Chimica Acta, 2002Co-Authors: Xiaoyu Shang, Zhuobin YuanAbstract:Abstract A cyclodextrin-modified Micellar electrokinetic chromatographic method was established to determine five anthraquinone derivatives and a distyrene derivative in Rhubarb. The six components were successfully separated by using the mixed Micellar System consisting of 20 mmol/l SC and 20 mmol/l STC with 15 mmol/l β-CD in the BGE of 20 mmol/l borax buffer (pH 11) in less than 20 min. Effect of SC and STC concentrations, pH of BGE and concentration of β-CD on the separation was studied. The analytical performance of the method was discussed in terms of linearity response, precision, detection limits, quantitation limits and recoveries. The method developed was applied to the determination of three commercial Rhubarb samples. The results obtained agreed with those of the reported documents.