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Dhellemmes L, Leclercq L, Lichtenauer L, Höchsmann A, Leitner M, Ebner A, Martin M, Neusüß C, Cottet H. Dual Contributions of Analyte Adsorption and Electroosmotic Inhomogeneity to Separation Efficiency in Capillary Electrophoresis of Proteins. Anal Chem 2024; 96:11172-11180. [PMID: 38946102 DOI: 10.1021/acs.analchem.4c00274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Improving separation efficiency in capillary electrophoresis (CE) requires systematic study of the influence of the electric field (or solute linear velocity) on plate height for a better understanding of the critical parameters controlling peak broadening. Even for poly(diallyldimethylammonium chloride) (PDADMAC)/poly(sodium styrenesulfonate) (PSS) successive multiple ionic-polymer layer (SMIL) coatings, which lead to efficient and reproducible separations of proteins, plate height increases with migration velocity, limiting the use of high electric fields in CE. Solute adsorption onto the capillary wall was generally considered as the main source of peak dispersion, explaining this plate height increase. However, experiments done with Taylor dispersion analysis and CE in the same conditions indicate that other phenomena may come into play. Protein adsorption with slow kinetics and few adsorption sites was established as a source of peak broadening for specific proteins. Surface charge inhomogeneity was also identified as a contribution to plate height due to local electroosmotic fluctuations. A model was proposed and applied to partial PDADMAC/poly(ethylene oxide) capillary coatings as well as PDADMAC/PSS SMIL coatings. Atomic force microscopy with topography and recognition imaging enabled the determination of roughness and charge distribution of the PDADMAC/PSS SMIL surface.
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Affiliation(s)
- Laura Dhellemmes
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier 34095, France
| | - Laurent Leclercq
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier 34095, France
| | - Lisa Lichtenauer
- Institute of Biophysics, Johannes Kepler University Linz, Linz 4020, Austria
| | - Alisa Höchsmann
- Faculty of Chemistry, Aalen University, Aalen 73430, Germany
| | - Michael Leitner
- Institute of Biophysics, Johannes Kepler University Linz, Linz 4020, Austria
| | - Andreas Ebner
- Institute of Biophysics, Johannes Kepler University Linz, Linz 4020, Austria
| | - Michel Martin
- PMMH, CNRS, ESPCI Paris-PSL, Sorbonne Université, Université de Paris, Paris 75005, France
| | | | - Hervé Cottet
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier 34095, France
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2
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Carlsson JA, Löfgren M, Amini A. Identity verification of monoclonal antibodies by triple injection capillary zone electrophoresis. J Sep Sci 2024; 47:e2400092. [PMID: 38819776 DOI: 10.1002/jssc.202400092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 06/01/2024]
Abstract
This paper presents an approach based on triple injection capillary zone electrophoresis for identification of monoclonal antibodies. The analyte to be identified is injected between two zones of a known reference. The distances between the reference zones (plug I and III) and the target zone (plug II) are adjusted by partial electrophoresis of the first and second injection plugs. The full migration time of the target analyte is calculated from the observed migration time by considering the migration times of the reference in the first and third injection plugs. The relative migration time, that is, the ratio between the full migration time of the analyte and the migration time of the reference in the third injection plug provides the basis for identification. Here, eight monoclonal antibodies, including a pair of biosimilars, were used interchangeably as both analyte and reference to investigate potential of the method. The relative migration time for a preliminary positive identification were found to vary between 0.994 and 1.006 (1.000 ± 0.006, p = 95%). Beside the relative migration time, isoform distribution, peak profiles, and early migrating peaks, originating from components in the pharmaceutical formulations, were successfully used to verify the identity of all tested monoclonal antibodies.
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Affiliation(s)
| | | | - Ahmad Amini
- Swedish Medical Products Agency, Uppsala, Sweden
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3
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Dhellemmes L, Leclercq L, Frick H, Höchsmann A, Schaschke N, Neusüß C, Cottet H. Investigating cationic and zwitterionic successive multiple ionic-polymer layer coatings for protein separation by capillary electrophoresis. J Chromatogr A 2024; 1720:464802. [PMID: 38507871 DOI: 10.1016/j.chroma.2024.464802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/22/2024]
Abstract
Successive multiple ionic-polymer layers (SMILs) have long since proved their worth in capillary electrophoresis as they ensure stable electroosmotic flow (EOF) and relatively high separation efficiency. Recently, we demonstrated that plotting the plate height (H) against the solute migration velocity (u) enabled a reliable quantitative evaluation of the coating performances in terms of separation efficiency. In this work, various physicochemical and chemical parameters of the SMIL coating were studied and optimized in order to decrease the slope of the ascending part of the H vs u curve, which is known to be controlled by the homogeneity in charge of the coating surface and by the possible residual solute adsorption onto the coating surface. SMILs based on poly(diallyldimethylammonium chloride) (PDADMAC) and poly(sodium styrene sulfonate) (PSS) were formed and the effect of each polyelectrolyte molar mass and of the number of polyelectrolyte layers (up to 21 layers) was studied. The use of polyethylene imine as an anchoring first layer was considered. More polyelectrolyte couples based on PDADMAC, polybrene, PSS, poly(vinyl sulfate), and poly(acrylic acid) were tested. Finally, zwitterionic polymers based on the poly(α-l-lysine) scaffold were synthesized and used as the last layer of SMILs, illustrating their ability to finetune the EOF, while maintaining good separation efficiency.
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Affiliation(s)
- Laura Dhellemmes
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Laurent Leclercq
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Henry Frick
- Faculty of Chemistry, Aalen University, Aalen, Germany
| | | | | | | | - Hervé Cottet
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France.
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4
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van der Burg D, Wätzig H, Sänger-van de Griend CE. Method development for quantitative monitoring of monoclonal antibodies in upstream cell-culture process samples with limited sample preparation - An evaluation of various capillary coatings. Electrophoresis 2023; 44:96-106. [PMID: 36239141 PMCID: PMC10099398 DOI: 10.1002/elps.202200144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 11/11/2022]
Abstract
Monoclonal antibodies (mAbs) have become an important class of biopharmaceuticals used for the treatment of various diseases. Their quantification during the manufacturing process is important. In this work, a capillary zone electrophoresis (CZE) method was developed for the monitoring of the mAb concentration during cell-culture processes. CZE method development rules are outlined, particularly discussing various capillary coatings, such as a neutral covalent polyvinyl alcohol coating, a dynamic successive multiple ionic-polymer coating, and dynamic coatings using background electrolyte additives such as triethanolamine (T-EthA) and triethylamine. The dynamic T-EthA coating resulted in most stable electro-osmotic flows and most efficient peak shapes. The method is validated over the range 0.1-10 mg/ml, with a linear range of 0.08-1.3 mg/ml and an extended range of 1-10 mg/ml by diluting samples in the latter concentration range 10-fold in water. The intraday precision and accuracy were 2%-12% and 88%-107%, respectively, and inter-day precision and accuracy were 4%-9% and 93%-104%, respectively. The precision and accuracy of the lowest concentration level (0.08 mg/ml) were slightly worse and still well in scope for monitoring purposes. The presented method proved applicable for analysing in-process cell-culture samples from different cell-culture processes and is possibly well suited as platform method.
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Affiliation(s)
- Debbie van der Burg
- Kantisto BV, Baarn, The Netherlands.,Department of Chemistry, KTH Royal Institute of Technology, Division of Applied Physical Chemistry, Stockholm, Sweden.,Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
| | - Hermann Wätzig
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
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Hamidli N, Pajaziti B, Andrási M, Nagy C, Gáspár A. Determination of human insulin and its six therapeutic analogues by capillary electrophoresis - mass spectrometry. J Chromatogr A 2022; 1678:463351. [PMID: 35905683 DOI: 10.1016/j.chroma.2022.463351] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 07/12/2022] [Accepted: 07/17/2022] [Indexed: 11/18/2022]
Abstract
In this work, human insulin and its 6 analogues were separated and determined using CZE-MS. Three different capillaries (bare fused silica, successive multiple ionic-polymer layer (SMIL) and static linear polyacrylamide (LPA) coated) were compared based on their separation performances in their optimal operating conditions. Coated capillaries demonstrated slightly better separation of the components, although some components showed wide, distorted peaks. The highest plate number could be obtained in the SMIL capillary (192 000/m). For UV and ESI-MS detection relatively similar LOD values were obtained (0.3-1.2 mg/L and 1.0-3.4 mg/L, respectively). The application of MS detection provided useful structural information and unambiguous identification for insulins having similar or the same molecular mass. This work is considered to be important not only for the investigation of insulins but also for its potential contribution to the top-down analysis of proteins using CE-MS.
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Affiliation(s)
- Narmin Hamidli
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary
| | - Blerta Pajaziti
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary
| | - Melinda Andrási
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary
| | - Cynthia Nagy
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary
| | - Attila Gáspár
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
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Roca S, Dhellemmes L, Leclercq L, Cottet H. Polyelectrolyte Multilayers in Capillary Electrophoresis. Chempluschem 2022; 87:e202200028. [PMID: 35388990 DOI: 10.1002/cplu.202200028] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/19/2022] [Indexed: 02/21/2024]
Abstract
Capillary electrophoresis (CE) has been proven to be a performant analytical method to analyze both small and macro molecules. Indeed, it is capable of separating compounds of the same nature according to differences in their charge to size ratios, particularly proteins, monoclonal antibodies and peptides. However, one of the major obstacles to reach high separation efficiency remains the adsorption of solutes on the capillary wall. Among the different coating approaches used to control and minimize solute adsorption, polyelectrolyte multilayers can be applied to CE as a versatile approach. These coatings are made up of alternating layers of polycations and polyanions, and may be used in acidic, neutral or basic conditions depending on the solutes to be analyzed. This Review provides an overview of Successive Multiple Ionic-polymer Layer (SMIL) coatings used in CE, looking at how different parameters induce variations on the electro-osmotic flow (EOF), separation efficiency and coating stability, as well as their promising applications in the biopharmaceutical field.
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Affiliation(s)
- Sébastien Roca
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Laura Dhellemmes
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Laurent Leclercq
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Hervé Cottet
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
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7
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Salzer L, Stolz A, Dhellemmes L, Höchsmann A, Leclercq L, Cottet H, Neusüß C. Successive Multiple Ionic-Polymer Layer Coatings for Intact Protein Analysis by Capillary Zone Electrophoresis-Mass Spectrometry: Application to Hemoglobin Analysis. Methods Mol Biol 2022; 2531:69-76. [PMID: 35941479 DOI: 10.1007/978-1-0716-2493-7_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Adsorption of analytes, e.g., proteins, often interfere with separation in CE, due to the relatively large surface of the narrow capillary. Coatings often are applied to prevent adsorption and to determine the electroosmotic flow (EOF), which is of major importance for the separation in CE. Successive multiple ionic-polymer layer (SMIL) coatings are frequently used for protein analysis in capillary electrophoresis resulting in high separation efficiency and repeatability. Here, the coating procedure of a five-layer SMIL coating is described using quaternized diethylaminoethyl dextran (DEAEDq) as polycation and poly(methacrylic acid) (PMA) as polyanion. Depending on the analyte, different polyions may be used to increase separation efficiency. However, the coating procedure remains the same.To demonstrate the applicability of SMIL coatings in CE-MS, human hemoglobin was measured in a BGE containing 2 M acetic acid. DEAEDq-PMA coating was found to be the most suitable for hemoglobin analysis due to relatively low reversed electroosmotic mobility leading to increased electrophoretic resolution of closely related proteoforms. Thereby, not only alpha and beta subunit of the hemoglobin could be separated, but also positional isoforms of glycated and carbamylated species were separated within 24 min.
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Affiliation(s)
- Liesa Salzer
- Faculty of Chemistry, Aalen University, Aalen, Germany
- Analytical BioGeoChemistry (BGC), Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Laura Dhellemmes
- Institut des Biomolécules Max Mousseron, UMR CNRS, Université de Montpellier, Montpellier, France
| | | | - Laurent Leclercq
- Institut des Biomolécules Max Mousseron, UMR CNRS, Université de Montpellier, Montpellier, France
| | - Hervé Cottet
- Institut des Biomolécules Max Mousseron, UMR CNRS, Université de Montpellier, Montpellier, France
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8
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Hafez IT, Biskos G. New method for the protection and restoration of calcareous cultural heritage stones by polyelectrolytes and hydroxyapatite nanocrystals. J Colloid Interface Sci 2021; 604:604-615. [PMID: 34280758 DOI: 10.1016/j.jcis.2021.07.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/01/2021] [Accepted: 07/02/2021] [Indexed: 11/29/2022]
Abstract
We have investigated the feasibility of a new two-step protocol for the restoration of marbles. The process employs a polyelectrolyte multilayer film that enhances the chemical affinity between the treated stone and restorative material (hydroxyapatite nanocrystals), through functionalization, while at the same time it attributes an acid resistant property to the resulting system. Surface functionalization and material deposition is achieved through spraying; a simple and versatile application method suitable for objects of various sizes and geometries. Polyelectrolyte (polyethylenimine and polyacrylic acid) deposition was examined through Attenuated Total Reflection Fourier-Transform Infrared Spectroscopy (ATR-FTIR) and Atomic Force Microscopy (AFM), and tested through contact angle, water absorption and dissolution experiments. The hydroxyapatite nanocrystals were studied by ATR-FTIR, z-potential, AFM and Scanning Electron Microscopy (SEM), and characterized via contact angle and color alteration measurements. Our results show that the polyelectrolyte multilayer was stable in an aqueous environment with increased acid resistance (up to 46% decrease in mass weight loss when compared with untreated samples) and decreased water absorption (up to 39%). Color measurements of the outer hydroxyapatite layer showed a minimal color alteration for one type of the tested substrates showing low color difference values (ΔΕ* < 5). The results suggest that the proposed method holds great potential for marble restoration as it attributes multi-functionality and is easy to apply.
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Affiliation(s)
- Iosif T Hafez
- Science and Technology in Archaeology and Culture Research Center, The Cyprus Institute, Nicosia 2121, Cyprus; Climate and Atmosphere Research Center, The Cyprus Institute, Nicosia 2121, Cyprus.
| | - George Biskos
- Climate and Atmosphere Research Center, The Cyprus Institute, Nicosia 2121, Cyprus; Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft 2628 CN, the Netherlands
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9
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Leclercq L, Renard C, Martin M, Cottet H. Quantification of Adsorption and Optimization of Separation of Proteins in Capillary Electrophoresis. Anal Chem 2020; 92:10743-10750. [DOI: 10.1021/acs.analchem.0c02012] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Laurent Leclercq
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier 34095, France
| | - Charly Renard
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier 34095, France
| | - Michel Martin
- PMMH, CNRS, ESPCI Paris − PSL, Sorbonne Université, Université de Paris, Paris 75005, France
| | - Hervé Cottet
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier 34095, France
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10
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Polyelectrolyte adsorption in single small nanochannel by layer-by-layer method. J Colloid Interface Sci 2020; 561:1-10. [DOI: 10.1016/j.jcis.2019.11.116] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 11/24/2022]
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11
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Leclercq L, Morvan M, Koch J, Neusüß C, Cottet H. Modulation of the electroosmotic mobility using polyelectrolyte multilayer coatings for protein analysis by capillary electrophoresis. Anal Chim Acta 2019; 1057:152-161. [DOI: 10.1016/j.aca.2019.01.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/17/2018] [Accepted: 01/04/2019] [Indexed: 12/26/2022]
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12
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Stock LG, Leitner M, Traxler L, Bonazza K, Leclercq L, Cottet H, Friedbacher G, Ebner A, Stutz H. Advanced portrayal of SMIL coating by allying CZE performance with in-capillary topographic and charge-related surface characterization. Anal Chim Acta 2017; 951:1-15. [DOI: 10.1016/j.aca.2016.10.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/22/2016] [Indexed: 10/20/2022]
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13
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Vitali L, Gonçalves S, Rodrigues V, Fávere VT, Micke GA. Development of a fast method for simultaneous determination of hippuric acid, mandelic acid, and creatinine in urine by capillary zone electrophoresis using polymer multilayer-coated capillary. Anal Bioanal Chem 2016; 409:1943-1950. [DOI: 10.1007/s00216-016-0142-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/28/2016] [Accepted: 12/09/2016] [Indexed: 10/20/2022]
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14
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Štěpánová S, Kašička V. Recent applications of capillary electromigration methods to separation and analysis of proteins. Anal Chim Acta 2016; 933:23-42. [DOI: 10.1016/j.aca.2016.06.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/10/2016] [Accepted: 06/03/2016] [Indexed: 10/21/2022]
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15
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Leitner M, Stock LG, Traxler L, Leclercq L, Bonazza K, Friedbacher G, Cottet H, Stutz H, Ebner A. Mapping molecular adhesion sites inside SMIL coated capillaries using atomic force microscopy recognition imaging. Anal Chim Acta 2016; 930:39-48. [PMID: 27265903 DOI: 10.1016/j.aca.2016.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 04/29/2016] [Accepted: 05/01/2016] [Indexed: 10/21/2022]
Abstract
Capillary zone electrophoresis (CZE) is a powerful analytical technique for fast and efficient separation of different analytes ranging from small inorganic ions to large proteins. However electrophoretic resolution significantly depends on the coating of the inner capillary surface. High technical efforts like Successive Multiple Ionic Polymer Layer (SMIL) generation have been taken to develop stable coatings with switchable surface charges fulfilling the requirements needed for optimal separation. Although the performance can be easily proven in normalized test runs, characterization of the coating itself remains challenging. Atomic force microscopy (AFM) allows for topographical investigation of biological and analytical relevant surfaces with nanometer resolution and yields information about the surface roughness and homogeneity. Upgrading the scanning tip to a molecular biosensor by adhesive molecules (like partly inverted charged molecules) allows for performing topography and recognition imaging (TREC). As a result, simultaneously acquired sample topography and adhesion maps can be recorded. We optimized this technique for electrophoresis capillaries and investigated the charge distribution of differently composed and treated SMIL coatings. By using the positively charged protein avidin as a single molecule sensor, we compared these SMIL coatings with respect to negative charges, resulting in adhesion maps with nanometer resolution. The capability of TREC as a functional investigation technique at the nanoscale was successfully demonstrated.
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Affiliation(s)
- Michael Leitner
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Lorenz G Stock
- Division of Chemistry and Bioanalytics, Department of Molecular Biology, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria; Christian Doppler Laboratory for Innovative Tools for the Characterization of Biosimilars, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
| | - Lukas Traxler
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Laurent Leclercq
- Institut des Biomolécules Max Mousseron (IBMM, UMR 5247, CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier), Place Eugène Bataillon, CC 1706, 34095 Montpellier, France
| | - Klaus Bonazza
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, 1060 Vienna, Austria
| | - Gernot Friedbacher
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, 1060 Vienna, Austria
| | - Hervé Cottet
- Institut des Biomolécules Max Mousseron (IBMM, UMR 5247, CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier), Place Eugène Bataillon, CC 1706, 34095 Montpellier, France
| | - Hanno Stutz
- Division of Chemistry and Bioanalytics, Department of Molecular Biology, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria; Christian Doppler Laboratory for Innovative Tools for the Characterization of Biosimilars, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
| | - Andreas Ebner
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria.
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Duša F, Witos J, Karjalainen E, Viitala T, Tenhu H, Wiedmer SK. Novel cationic polyelectrolyte coatings for capillary electrophoresis. Electrophoresis 2015; 37:363-71. [DOI: 10.1002/elps.201500275] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 09/17/2015] [Accepted: 10/05/2015] [Indexed: 01/07/2023]
Affiliation(s)
- Filip Duša
- Department of Chemistry; University of Helsinki; Helsinki Finland
| | - Joanna Witos
- Department of Chemistry; University of Helsinki; Helsinki Finland
| | - Erno Karjalainen
- Laboratory of Polymer chemistry, Department of Chemistry; University of Helsinki; Helsinki Finland
| | - Tapani Viitala
- Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy; University of Helsinki; Helsinki Finland
| | - Heikki Tenhu
- Laboratory of Polymer chemistry, Department of Chemistry; University of Helsinki; Helsinki Finland
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17
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Duša F, Ruokonen SK, Petrovaj J, Viitala T, Wiedmer SK. Ionic liquids affect the adsorption of liposomes onto cationic polyelectrolyte coated silica evidenced by quartz crystal microbalance. Colloids Surf B Biointerfaces 2015; 136:496-505. [PMID: 26454056 DOI: 10.1016/j.colsurfb.2015.09.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 09/09/2015] [Accepted: 09/28/2015] [Indexed: 01/28/2023]
Abstract
The worldwide use of ionic liquids (ILs) is steadily increasing, and even though they are often referred to as "green solvents" they have been reported to be toxic, especially toward aquatic organisms. In this work, we thoroughly study two phosphonium ILs; octyltributylphosphonium chloride ([P8444]Cl) and tributyl(tetradecyl)phosphonium chloride ([P14444]Cl). Firstly, the critical micelle concentrations (CMCs) of the ILs were determined with fluorescence spectroscopy and the optical pendant drop method in order to gain an understanding of the aggregation behavior of the ILs. Secondly, a biomimicking system of negatively charged unilamellar liposomes was used in order to study the effect of the ILs on biomembranes. Changes in the mechanical properties of adsorbed liposomes were determined by quartz crystal microbalance (QCM) measurements with silica coated quartz crystal sensors featuring a polycation layer. The results confirmed that both ILs were able to incorporate and alter the biomembrane structure. The membrane disrupting effect was emphasized with an increasing concentration and alkyl chain length of the ILs. In the extreme case, the phospholipid membrane integrity was completely compromised.
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Affiliation(s)
- Filip Duša
- Department of Chemistry, P.O. Box 55, 00014 University of Helsinki, Finland
| | | | - Ján Petrovaj
- Department of Chemistry, P.O. Box 55, 00014 University of Helsinki, Finland
| | - Tapani Viitala
- Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, P.O. Box 56, 00014 University of Helsinki, Finland.
| | - Susanne K Wiedmer
- Department of Chemistry, P.O. Box 55, 00014 University of Helsinki, Finland.
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Bekri S, Leclercq L, Cottet H. Polyelectrolyte multilayer coatings for the separation of proteins by capillary electrophoresis: Influence of polyelectrolyte nature and multilayer crosslinking. J Chromatogr A 2015; 1399:80-7. [DOI: 10.1016/j.chroma.2015.04.033] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 04/17/2015] [Accepted: 04/20/2015] [Indexed: 10/23/2022]
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Quantification of thickness and wrinkling of exfoliated two-dimensional zeolite nanosheets. Nat Commun 2015; 6:7128. [PMID: 25958985 PMCID: PMC4432588 DOI: 10.1038/ncomms8128] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/02/2015] [Indexed: 11/08/2022] Open
Abstract
Some two-dimensional (2D) exfoliated zeolites are single- or near single-unit cell thick silicates that can function as molecular sieves. Although they have already found uses as catalysts, adsorbents and membranes precise determination of their thickness and wrinkling is critical as these properties influence their functionality. Here we demonstrate a method to accurately determine the thickness and wrinkles of a 2D zeolite nanosheet by comprehensive 3D mapping of its reciprocal lattice. Since the intensity modulation of a diffraction spot on tilting is a fingerprint of the thickness, and changes in the spot shape are a measure of wrinkling, this mapping is achieved using a large-angle tilt-series of electron diffraction patterns. Application of the method to a 2D zeolite with MFI structure reveals that the exfoliated MFI nanosheet is 1.5 unit cells (3.0 nm) thick and wrinkled anisotropically with up to 0.8 nm average surface roughness.
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New insights in carbohydrate-deficient transferrin analysis with capillary electrophoresis–mass spectrometry. Forensic Sci Int 2014; 243:14-22. [DOI: 10.1016/j.forsciint.2014.03.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/21/2014] [Accepted: 03/12/2014] [Indexed: 11/21/2022]
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