1
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Oleic and nitro-oleic acid behavior at an electrified water-1,2-dichloroethane interface. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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2
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Wang TX, Li XX, Chen L, Li L, Janaswamy S. Carriers Based on Zein-Dextran Sulfate Sodium Binary Complex for the Sustained Delivery of Quercetin. Front Chem 2020; 8:662. [PMID: 33195002 PMCID: PMC7555997 DOI: 10.3389/fchem.2020.00662] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/26/2020] [Indexed: 12/19/2022] Open
Abstract
Herein, a self-assembly formulation of Zein and dextran sulfate sodium (DSS) binary complex has been developed for the quercetin (Que) delivery. The prepared particles display a smooth sphere in the range of 180 ~ 250 nm. The addition of DSS shields the Trp residues of Zein that were located on the hydrophilic exterior and in-turn reduces the surface hydrophobicity of the nanoparticles. The presence of DSS, indeed, increases the encapsulation efficiency of Que from the initial 45.9 in the Zein to 72.6% in the Zein/DSS binary complex. A significant reduction of Que diffusion in the simulated intestinal conditions has been observed with the addition of DSS on the nanoparticles, which also improves Que bioavailability. The release mechanism of Que-loaded Zein/DSS composites is in accordance with the Higuchi model (Q = 0.0913t0.5+0.1652, R2 = 0.953). Overall, nanoparticles based on Zein-DSS complexes stand out as an attractive carrier system of quercetin and the outcome could be extended to several bioactive compounds.
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Affiliation(s)
- Tian-Xing Wang
- Ministry of Education Engineering Research Center of Starch and Protein Processing, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Xiao-Xi Li
- Ministry of Education Engineering Research Center of Starch and Protein Processing, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Ling Chen
- Ministry of Education Engineering Research Center of Starch and Protein Processing, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Lin Li
- Ministry of Education Engineering Research Center of Starch and Protein Processing, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Srinivas Janaswamy
- Department of Dairy and Food Science, South Dakota State University, Brookings, SD, United States
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3
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Makyła-Juzak K, Chachaj-Brekiesz A, Dynarowicz-Latka P, Dąbczyński P, Zemla J. The Effect of Dextran Sulfate-as Model Glycosaminoglycan Analogue-on Membrane Lipids: DPPC, Cholesterol, and DPPC-Cholesterol Mixture. The Monolayer Study. J Membr Biol 2018; 251:641-651. [PMID: 30030544 PMCID: PMC6244761 DOI: 10.1007/s00232-018-0041-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/09/2018] [Indexed: 01/04/2023]
Abstract
Glycosaminoglycans (GAGs) are essential components of the extracellular matrices (ECMs) located on the outer surface of cellular membranes. They belong to the group of polysaccharides involved in diverse biological processes acting on the surface and across natural lipid membranes. Recently, particular attention has been focused on possible role of GAGs in the amyloid deposits. The amyloid formation is related to a disorder in protein folding, causing that soluble-in normal conditions-peptides become deposited extracellularly as insoluble fibrils, impairing tissue structure and its function. One of the hypothesis holds that GAGs may inhibit amyloid formation by interacting with the lipid membrane by blocking the accumulation of protein aggregates on the membrane surface. Although the biophysical properties of GAGs are described rather well, little is known about the nature of association between these polysaccharides and components of natural cell membranes. Therefore, a study of GAGs influence on membrane lipids is of particular importance. The aim of the present work is to get insight into the effect of hydrophilic dextran sulfate (DS)-that can be considered as GAG analogue-on membrane lipids organization. This study was based on examining interactions between DS sodium salt of molecular weight equal to about 40 kDa (DS40), dissolved in water subphase, and a model membrane, mimicked as Langmuir monolayer, formed by representative natural membrane lipids: cholesterol and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) as well as their mixtures. Due to the fact that calcium ions in excess may accumulate in the lipid membrane, attracting high molecular weight molecules to their surface, the influence of calcium ions present in the subphase on the DS40 activity has also been examined. It has been found that negatively charged DS, forming a sublayer underneath the monolayer, barely interacts with membrane lipids; however, in the presence of calcium ions the electrostatic interactions between DS40 and lipid membrane are significantly enhanced, leading to the formation of network-like crystalline structures at the surface of model membrane, which can prevent incorporation and interaction with other extracellular molecules, e.g., proteins.
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Affiliation(s)
- Katarzyna Makyła-Juzak
- Department of General Chemistry, Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland.
| | - Anna Chachaj-Brekiesz
- Department of General Chemistry, Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
| | - Patrycja Dynarowicz-Latka
- Department of General Chemistry, Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
| | - Paweł Dąbczyński
- Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348, Kraków, Poland
| | - Joanna Zemla
- Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342, Kraków, Poland
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4
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Manzanares JA, Johans C, Cervera J. Distribution potential in electrified microemulsions with potential determining salts. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.08.049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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5
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Li C, Zheng B, Zhang T, Zhao J, Gu Y, Yan X, Li Y, Liu W, Feng G, Zhang Z. Petal-like graphene–Ag composites with highly exposed active edge sites were designed and constructed for electrochemical determination of metronidazole. RSC Adv 2016. [DOI: 10.1039/c6ra01334a] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The petal-like graphene–Ag composites with highly exposed active edge sites were constructed, which served as both the electrocatalyst and the current amplifier for electrochemical detection of metronidazole.
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Affiliation(s)
- Cong Li
- College of Chemistry
- Jilin University
- Changchun 130012
- China
| | - Bo Zheng
- College of Chemistry
- Jilin University
- Changchun 130012
- China
| | - Tingting Zhang
- College of Chemistry
- Jilin University
- Changchun 130012
- China
| | - Jingyu Zhao
- College of Chemistry
- Jilin University
- Changchun 130012
- China
| | - Yue Gu
- College of Chemistry
- Jilin University
- Changchun 130012
- China
| | - Xiaoyi Yan
- College of Chemistry
- Jilin University
- Changchun 130012
- China
| | - Yaru Li
- College of Chemistry
- Jilin University
- Changchun 130012
- China
| | - Weilu Liu
- School of Pharmacy
- Shenyang Pharmaceutical University
- Shenyang 110016
- China
| | - Guodong Feng
- College of Chemistry
- Jilin University
- Changchun 130012
- China
| | - Zhiquan Zhang
- College of Chemistry
- Jilin University
- Changchun 130012
- China
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6
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Li Z, Zheng X, Sheng Q, Yang Z, Zheng J. Preparation of Au@Ag nanoparticles at a gas/liquid interface and their application for sensitive detection of hydrogen peroxide. RSC Adv 2016. [DOI: 10.1039/c5ra26857e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Preparation of Au@Ag NPs at a gas/liquid interface by a seed-mediated growth procedure and their application for sensitive detection of hydrogen peroxide.
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Affiliation(s)
- Zhi Li
- Institute of Analytical Science
- Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry
- Northwest University
- Xi'an
- China
| | - Xiaohui Zheng
- Institute of Analytical Science
- Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry
- Northwest University
- Xi'an
- China
| | - Qinglin Sheng
- Institute of Analytical Science
- Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry
- Northwest University
- Xi'an
- China
| | - Ziyin Yang
- Institute of Analytical Science
- Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry
- Northwest University
- Xi'an
- China
| | - Jianbin Zheng
- Institute of Analytical Science
- Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry
- Northwest University
- Xi'an
- China
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7
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Bai W, Sheng Q, Zheng J. Morphology controlled synthesis of platinum nanoparticles performed on the surface of graphene oxide using a gas–liquid interfacial reaction and its application for high-performance electrochemical sensing. Analyst 2016; 141:4349-58. [DOI: 10.1039/c6an00632a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrochemical sensing of nitrite based on morphology-controlled Pt/GO nanocomposites which were obtained using a novel gas–liquid interfacial reaction.
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Affiliation(s)
- Wushuang Bai
- Institute of Analytical Science
- Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry
- Northwest University
- Xi'an
- China
| | - Qinglin Sheng
- Institute of Analytical Science
- Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry
- Northwest University
- Xi'an
- China
| | - Jianbin Zheng
- Institute of Analytical Science
- Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry
- Northwest University
- Xi'an
- China
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8
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Castañeda AD, Alligrant TM, Loussaert JA, Crooks RM. Electrocatalytic amplification of nanoparticle collisions at electrodes modified with polyelectrolyte multilayer films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:876-885. [PMID: 25568965 DOI: 10.1021/la5043124] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report electrochemical catalytic amplification of individual collisions between ∼57 nm diameter Pt nanoparticles (Pt NPs) and 12.5 μm diameter Au ultramicroelectrodes modified with passivating, electrostatically assembled polyelectrolyte multilayer (PEM) films prepared by the layer-by-layer deposition method. Two key findings are reported. First, despite the thicknesses of the insulating PEM films, which range up to 5 nm, electrons are able to tunnel from the Pt NPs to the electrode resulting in electrocatalytic N2H4 oxidation at the PEM film-solution interface. These single-particle measurements are in accord with prior reports showing that the electrochemical activity of passive PEM films can be reactivated by adsorption of metallic NPs. Second, it is possible to control the frequency of the collisions by manipulating the net electrostatic charge present on the outer surface of the PEM thin film. These results, which demonstrate that chemistry can be used to control electrocatalytic amplification, set the stage for future sensing applications.
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Affiliation(s)
- Alma D Castañeda
- Department of Chemistry, Center for Electrochemistry, and the Center for Nano- and Molecular Science and Technology, The University of Texas at Austin , 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States
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9
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Bai W, Nie F, Zheng J, Sheng Q. Novel silver nanoparticle-manganese oxyhydroxide-graphene oxide nanocomposite prepared by modified silver mirror reaction and its application for electrochemical sensing. ACS APPLIED MATERIALS & INTERFACES 2014; 6:5439-5449. [PMID: 24660983 DOI: 10.1021/am500641d] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A gas/liquid interface will be formed when the free volatilized methyl aldehyde gas begins to dissolve in to solution. On the basis of the traditional silver mirror reaction, silver nanoparticle-manganese oxyhydroxide-graphene oxide (Ag-MnOOH-GO) nanocomposite was synthesized at the gas/liquid interface without any protection of inert gas at room temprature. The morphology of the nanocomposites could be controlled by adjusting the reaction temperature and time. The morphology and composition of the nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The composites were then applied for electrochemical sensing. The electrochemical investigation for the sensor indicates that it has excellent property to catalyze H2O2, and could detect H2O2 with a low detection limit of 0.2μM and wide linear range of 0.5 μM to 17.8 mM. The present study provides a general platform for the controlled synthesis of nanomaterials and can be extended to other optical, electronic, and magnetic nanocompounds.
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Affiliation(s)
- Wushuang Bai
- Institute of Analytical Science, Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University , Xi'an, Shaanxi 710069, China
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10
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Determination of the substitution degree of modified chitosan by cyclic voltammetry at the water/dichloroethane interface. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2013.11.146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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11
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Potential-mediated interaction between dextran sulfate and negatively charged phospholipids films at air/water and liquid/liquid interfaces. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.09.137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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Riva J, Iglesias R, Yudi L. Electrochemical adsorption of a cationic cellulosic polymer by ion pair formation at the interface between two immiscible electrolyte solutions. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.06.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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13
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Liu Z, Ma Z. Fabrication of an ultrasensitive electrochemical immunosensor for CEA based on conducting long-chain polythiols. Biosens Bioelectron 2013; 46:1-7. [DOI: 10.1016/j.bios.2013.02.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 02/13/2013] [Indexed: 12/25/2022]
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14
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Ghostine RA, Markarian MZ, Schlenoff JB. Asymmetric Growth in Polyelectrolyte Multilayers. J Am Chem Soc 2013; 135:7636-46. [DOI: 10.1021/ja401318m] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ramy A. Ghostine
- Department of Chemistry
and Biochemistry, The Florida State University, Tallahassee, Florida
32306-4390, United States
| | - Marie Z. Markarian
- Department of Chemistry
and Biochemistry, The Florida State University, Tallahassee, Florida
32306-4390, United States
| | - Joseph B. Schlenoff
- Department of Chemistry
and Biochemistry, The Florida State University, Tallahassee, Florida
32306-4390, United States
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15
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Cecchini MP, Turek VA, Paget J, Kornyshev AA, Edel JB. Self-assembled nanoparticle arrays for multiphase trace analyte detection. NATURE MATERIALS 2013; 12:165-71. [PMID: 23160268 DOI: 10.1038/nmat3488] [Citation(s) in RCA: 238] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 10/09/2012] [Indexed: 05/22/2023]
Abstract
Nanoplasmonic structures designed for trace analyte detection using surface-enhanced Raman spectroscopy typically require sophisticated nanofabrication techniques. An alternative to fabricating such substrates is to rely on self-assembly of nanoparticles into close-packed arrays at liquid/liquid or liquid/air interfaces. The density of the arrays can be controlled by modifying the nanoparticle functionality, pH of the solution and salt concentration. Importantly, these arrays are robust, self-healing, reproducible and extremely easy to handle. Here, we report on the use of such platforms formed by Au nanoparticles for the detection of multi-analytes from the aqueous, organic or air phases. The interfacial area of the Au array in our system is ≈25 mm(2) and can be made smaller, making this platform ideal for small-volume samples, low concentrations and trace analytes. Importantly, the ease of assembly and rapid detection make this platform ideal for in-the-field sample testing of toxins, explosives, narcotics or other hazardous chemicals.
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Affiliation(s)
- Michael P Cecchini
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
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16
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Synthesis of three-dimensional network Fe3O4 at gas/liquid interface and its sensing application. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.01.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Hartvig RA, van de Weert M, Ostergaard J, Jorgensen L, Jensen H. Formation of dielectric layers and charge regulation in protein adsorption at biomimetic interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:1804-1815. [PMID: 22185404 DOI: 10.1021/la204309a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Protein charge is an important parameter in the understanding of protein interactions and function. Proteins are subject to dynamic charge regulation, that is, the influence of the local environment (such as charged interfaces and biopolymers) on protein charge. Charge regulation is governed by differences in the dielectric and electrostatic environment between adsorbed protein and the free protein in bulk solution. In this work protein charge regulation is addressed experimentally by employing electrochemistry at interfaces between two immiscible electrolyte solutions (ITIES) as well as theoretically by developing a new protein adsorption model at ITIES. Electrochemistry at ITIES is shown to be particularly well suited to study protein charge regulation as the adsorbed protein experiences a different dielectric environment compared to the bulk phase and the external control of the water/oil potential difference allows systematic studies on how potential induced ion gradients affect protein charge. The theoretical model incorporates all the features of the experimental system and specifically takes into account protein charge regulation at ITIES as well as the impact of the formation of dielectric layers on the experimentally observed impedance. The model parameters include the protein charge-pH profile, bulk pH, and the overall potential difference. It is shown that the formation of a dielectric layer and the associated charge regulation are the main factors dictating the observed experimental behavior. Finally, the theoretical model is used to interpret literature results, and the consistency between the model and the relatively large data set suggests that the model may be used more generally for understanding and predicting protein adsorption.
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Affiliation(s)
- Rune A Hartvig
- Department of Pharmaceutics and Analytical Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
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18
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Santos HA, García-Morales V, Pereira CM. Electrochemical properties of phospholipid monolayers at liquid-liquid interfaces. Chemphyschem 2010; 11:28-41. [PMID: 19943272 DOI: 10.1002/cphc.200900609] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Biomembrane models built at the interface between two immiscible electrolytes (ITIES) are useful systems to study phenomena of biological relevance by means of their electrochemical processes. The unique properties of ITIES allow one either to control or measure the potential difference across the biomimetic membranes. Herein we focus on phospholipid monolayers adsorbed at liquid-liquid interfaces, and besides discussing recent developments on the subject, we describe electrochemical techniques that can be used to get insight on the interfacial processes and electrostatic properties of phospholipid membranes at the ITIES. In particular, we examine the electrochemical and physicochemical properties of (modified) phospholipid monolayers and their interaction with other biologically relevant compounds. The use of liquid-liquid electrochemistry as a powerful tool to characterize drug properties is outlined. Although this review is not a survey of all the work in the field, it provides a comprehensive referencing to current research.
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Affiliation(s)
- Hélder A Santos
- Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 Viikinkaari 5 E, 00014, Finland.
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19
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Santos HA, Manzanares JA, Murtomäki L, Kontturi K. Thermodynamic analysis of binding between drugs and glycosaminoglycans by isothermal titration calorimetry and fluorescence spectroscopy. Eur J Pharm Sci 2007; 32:105-14. [PMID: 17643273 DOI: 10.1016/j.ejps.2007.06.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Revised: 03/13/2007] [Accepted: 06/12/2007] [Indexed: 10/23/2022]
Abstract
The thermodynamics of the interaction of positively charged drug molecules with negatively charged glycosaminoglycans (GAGs) is investigated by isothermal titration calorimetry (ITC) and fluorescence spectroscopy. The drugs considered are propranolol hydrochloride, tacrine, and aminacrine, and the polymers used as model GAGs are dextran sulfate, chondroitin sulfate, and hyaluronic acid. The ITC results show that the interaction between drugs and GAGs is via direct binding and that GAGs bind to drugs at one set of sites. Large negative values of heat capacity change (DeltaC(p)) are observed upon binding of GAGs to drugs. Such negative DeltaC(p) is not expected for purely electrostatic interactions and suggests that hydrophobic and other interactions may be also involved in the binding process. These results are corroborated by fluorescence spectroscopy measurements, which show that specific drug/GAG complex formation is accompanied by a clear enhancement of the fluorescence intensity. The results highlight the importance of the formation of drug/GAG complexes as a primary step for the drug delivery process into cell membranes. It is concluded that the interactions are dependent on the nature of both GAG and drug and this is a fact to be taken into account when new drugs are designed.
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Affiliation(s)
- Hélder A Santos
- Department of Chemical Technology, Laboratory of Physical Chemistry and Electrochemistry, Helsinki University of Technology, PO Box 6100, FIN-02015 HUT, Finland.
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20
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Santos HA, Ferreira ES, Pereira EJ, Pereira CM, Kontturi K, Silva F. Adsorption–Penetration Studies of Glucose Oxidase into Phospholipid Monolayers at the 1,2-Dichloroethane/Water Interface. Chemphyschem 2007; 8:1540-7. [PMID: 17569093 DOI: 10.1002/cphc.200700137] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The interaction between glucose oxidase (GOx) and phospholipid monolayers is studied at the 1,2-dichloroethane/water interface by electrochemical impedance spectroscopy. Electrochemical experiments show that the presence of GOx induces changes in the capacitance curves at both negative and positive potentials, which are successfully explained by a theoretical model based on the solution of the Poisson-Boltzmann equation. These changes are ascribed to a reduced partition coefficient of GOx and an increase of the permittivity of the lipid hydrocarbon domain. Our results show that the presence of lipid molecules enhances the adsorption of GOx molecules at the liquid/liquid interface. At low lipid concentrations, the adsorption of GOx is probably the first step preceding its penetration into the lipid monolayer. The experimental results indicate that GOx penetrates better and forms more stable monolayers for lipids with longer hydrophobic tails. At high GOx concentrations, the formation of multilayers is observed. The phenomenon described here is strongly dependent on 1) the GOx and lipid concentrations, 2) the nature of the lipid, and 3) the potential drop across the interface.
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Affiliation(s)
- Hélder A Santos
- Laboratory of Physical Chemistry and Electrochemistry, Department of Chemical Technology, Helsinki University of Technology, P.O. Box 6100, Kemistintie 1, 02015 HUT Espoo, Finland.
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21
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Santos HA, Carlsson S, Murtomäki L, Kontturi K. Effect of Gramicidin on Phospholipid-Modified Monolayers and on Ion Transfer at a Liquid–Liquid Interface. Chemphyschem 2007; 8:913-20. [PMID: 17366646 DOI: 10.1002/cphc.200600767] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The interaction of hybrid lipid/gramicidin A (gA) monolayers with dextran sulfate (DS) and the effect of this interaction on ion transfer at a liquid-liquid interface is reported. The interfacial and physicochemical properties are studied with Langmuir-Blodgett (LB) and electrochemical techniques. The results obtained from compression isotherms demonstrate that the interactions between the different species in the hybrid monolayer vary according to the chemical nature of the lipid (hydrocarbon region and charge of the head group). Interfacial capacitance measured with AC voltammetry indicates that the DS chains form a rather flat and compact layer when adsorbed to either zwitterionic or negatively charged phospholipid monolayers, and that calcium, even at low concentrations, interacts with the monolayers. These results are successfully described by a model based on the solution of the Poisson-Boltzmann equation in the interfacial region. Ion transfer and interactions with the lipid/gA/DS-modified monolayers were also studied with electrochemical techniques. Admittance data show that although the studied ions are not using gA channels for the transfer through the lipid membranes, the incorporation of gA in the lipid domain and the adsorption of DS at the interface have a significant effect on ion transfer across the monolayers. This effect can be explained as a consequence of the modified surface charge and of the compactness of the lipid domain due to its interaction with gA and to calcium and DS adsorption at the interface. The ion-transfer rate, therefore, depends on the composition of the monolayer and the chemical nature of the ion.
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Affiliation(s)
- Hélder A Santos
- Department of Chemical Technology, Laboratory of Physical Chemistry and Electrochemistry, Helsinki University of Technology, P.O. Box 6100, Kemistintie 1, 02015 TKK Espoo, Finland.
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Martins M, Pereira C, Santos H, Dabirian R, Silva F, Garcia-Morales V, Manzanares J. Analysis of adsorption of phospholipids at the 1,2-dichloroethane/water interface by electrochemical impedance spectroscopy: A study of the effect of the saturated alkyl chain. J Electroanal Chem (Lausanne) 2007. [DOI: 10.1016/j.jelechem.2006.07.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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23
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Santos HA, García-Morales V, Murtomäki L, Manzanares JA, Kontturi K. Preparation of nanostructures composed of dextran sulfate/ruthenium nanoparticles and their interaction with phospholipid monolayers at a liquid–liquid interface. J Electroanal Chem (Lausanne) 2007. [DOI: 10.1016/j.jelechem.2006.01.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Carlsson S, Kontturi AK, Kontturi K. Improving membrane activity of oligonucleotides by cetylpyridinium chloride: an electrochemical study. Eur J Pharm Sci 2006; 29:451-9. [PMID: 17011756 DOI: 10.1016/j.ejps.2006.08.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Revised: 08/02/2006] [Accepted: 08/20/2006] [Indexed: 10/24/2022]
Abstract
The interaction of phospholipid membranes and oligonucleotides complexed with a positively charged surfactant is reported. Phospholipid membranes were assembled at the interface between an immobilized organic phase and an aqueous phase using the Langmuir-Blodgett (L-B) technique. The interaction and adsorption of the naked oligonucleotides and oligonucleotides complexed with cetylpyridinium chloride (CP) was studied electrochemically using cyclic voltammetry (CV) and ac-voltammetry. Interfacial capacitance, obtained indirectly from ac-voltammetry as a function of interfacial potential, was fitted to the theory based on the solution of the Poisson-Boltzmann equation. It was shown that both types of naked oligonucleotides (phosphoromonothioates and phosphodiesters) adsorb on the lipid monolayers poorly. The introduction of CP to the system increases the adsorption efficiency significantly. However, one phosphoromonothioate appeared to form a compact globule with CP instead of adsorbing to the lipid membrane. These results demonstrate that electrochemical methods are a powerful tool for probing the behavior of drugs in the vicinity of model cell membranes.
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Affiliation(s)
- Sanna Carlsson
- Laboratory of Physical Chemistry and Electrochemistry, Helsinki University of Technology, PO Box 6100, FIN-02015 Hut, Finland
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