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  • 1.
    Andersson, Margaretha
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Elihn, K.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Fromell, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Caldwell, Karin
    Surface attachment of nanoparticles using oligonucleotides2004In: Colloids and Surfaces B: Biointerfaces, Vol. 34, p. 165-171Article in journal (Refereed)
    Abstract [en]

    Colloidal polymer particles are widely used in a variety of applications ranging from chromatography to surface modified bioreactors in protein arrays. In the present study, surface attachment of polystyrene particles to a polystyrene substrate has been p

  • 2.
    Andersson, Margaretha
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Physical and Analytical Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Fromell, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Physical and Analytical Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Gullberg, Elisabet
    Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy. Department of Physical and Analytical Chemistry, Surface Biotechnology.
    Artursson, Per
    Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy. Department of Physical and Analytical Chemistry, Surface Biotechnology.
    Caldwell, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Physical and Analytical Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Characterization of Surface-Modified Nanoparticles for in Vivo Biointeraction. A Sedimentation Field Flow Fractionation Study2005In: Analytical Chemistry, Vol. 77, p. 5488-5493Article in journal (Refereed)
    Abstract [en]

    Sedimentation field flow fractionation (SdFFF) is an emerging high-performance analytical tool for separation and determination of size and adsorption characteristics of colloidal particles. This study demonstrates how SdFFF can be used to characterize nanoparticles prepared for in vivo applications including (1) the quantification of polymer uptake on nanoparticles where surface coverage is crucial and (2) the coupling of cell adhesive peptides containing the Arg-Gly-Asp motif (RGD). Quantitative information about polymer adhesion in order to prepare a bioinert surface and an accurate determination of ligand uptake are both of obvious importance for the understanding of, for example, relations between the number of attached molecules for biointeraction and an observed therapeutic effect. In addition, the present work highlights the necessity to perform careful characterization of commercially available particulate starting materials, in terms of size and polydispersity, prior to biological experimentation.

  • 3.
    Arnell, Robert
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Development and Validation of Methods for Characterization of Multi-Component Systems in Preparative LC2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis concerns the development and validation of methods for characterization of multi-component preparative LC systems. Measurements of competitive adsorption isotherms are performed to gain detailed information about the interactions inside the chromatography column. This information increases our understanding of the separation process and makes it possible to perform computer simulations and numerical optimizations to find optimal operating conditions.

    The methods under focus are called “the tracer-pulse method”, “the inverse method”, and “the inverse method on plateaus”. They are extensions of existing methods, with new experimental and numerical procedures to enable rapid and accurate multi-component adsorption isotherm determination. In the validation it was shown that they can produce results agreeing with traditional methods and that the acquired adsorption isotherm parameters can be used in simulations to accurately predict the outcome of preparative LC separations.

    The methods were used to characterize several complex LC systems and two phenomena were discovered and theoretically treated: 1) The presence of invisible deformed peaks in single-component systems. 2) Peak deformations encountered with modern chiral stationary phases, caused by strongly adsorbed eluent additives. The latter type of deformation was highly tuneable and it was possible to adjust the enantiomer peak shapes so that the peaks tailed in opposite directions with the sharp sides in between, yielding baseline resolution at remarkably high sample loads.

    In a final applied study both the LC-based perturbation peak method and a biosensor method based on surface plasmon resonance (SPR) were used for the first time for detailed characterization of chiral drug-protein interactions. The fundamental properties of the two very different methods were compared and it was found that the LC method is more suitable for multi-component analysis and that the SPR method is more suitable for stronger interactions.

    List of papers
    1. Validation of the Tracer-Pulse Method for Multi-Component Liquid Chromatography. A Classical Paradox Revisited
    Open this publication in new window or tab >>Validation of the Tracer-Pulse Method for Multi-Component Liquid Chromatography. A Classical Paradox Revisited
    2006 (English)In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 78, no 13, p. 4615-4623Article in journal (Refereed) Published
    Abstract [en]

    The tracer-pulse method was extended and validated for the determination of multicomponent adsorption isotherms in liquid chromatography. Competitive adsorption isotherms can be determined for any number of solutes, up to the column resolution limit. The basic principle is to equilibrate the column with an eluent containing a mixture of the solutes and then measure the migration velocity of each of them through the column. It is easy to calculate the stationary phase concentrations from these velocities, given the eluent composition. As in frontal analysis, real competitive isotherm data are measured using this method, unlike other methods, which only produce parametric estimates. The method was used to measure the binary isotherms of beta-blockers on a Kromasil C8 column. The data were fitted to competitive bi-Langmuir adsorption isotherm functions and was found to agree well with the results of frontal analysis and the perturbation method. Computer simulations based on the isotherm parameters were performed and displayed very good agreement with the experimental chromatograms. An intriguing and seemingly paradoxical property is visualized and discussed: the fact that the injected molecules are not found in the detected peaks.

    National Category
    Analytical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-95289 (URN)10.1021/ac0601260 (DOI)000238665200051 ()16808473 (PubMedID)
    Available from: 2006-12-22 Created: 2006-12-22 Last updated: 2018-01-23Bibliographically approved
    2. Invisible Analyte Peak Deformations in Single Component Liquid Chromatography
    Open this publication in new window or tab >>Invisible Analyte Peak Deformations in Single Component Liquid Chromatography
    2006 In: Analytical Chemistry, ISSN 10.1021/ac0522308, Vol. 78, no 8, p. 2765-2771Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-95290 (URN)
    Available from: 2006-12-22 Created: 2006-12-22Bibliographically approved
    3. An improved algorithm for solving inverse problems in liquid chromatography
    Open this publication in new window or tab >>An improved algorithm for solving inverse problems in liquid chromatography
    2006 (English)In: Computers and Chemical Engineering, ISSN 0098-1354, E-ISSN 1873-4375, Vol. 30, p. 1381-1391Article in journal (Refereed) Published
    Keywords
    inverse problem, inverse method, PDE, liquid chromatography (LC), adsorption isotherms
    National Category
    Computational Mathematics Analytical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-95291 (URN)10.1016/j.compchemeng.2006.03.004 (DOI)000239163300005 ()
    Available from: 2006-12-22 Created: 2006-12-22 Last updated: 2018-01-23Bibliographically approved
    4. Accurate and rapid estimation of adsorption isotherms in liquid chromatography using the inverse method on plateaus
    Open this publication in new window or tab >>Accurate and rapid estimation of adsorption isotherms in liquid chromatography using the inverse method on plateaus
    2005 (English)In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1099, p. 167-174Article in journal (Refereed) Published
    Keywords
    inverse method, numerical method, LC, competitive adsorption isotherms
    National Category
    Analytical Chemistry Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-95292 (URN)10.1016/j.chroma.2005.10.043 (DOI)
    Available from: 2006-12-22 Created: 2006-12-22 Last updated: 2018-01-23Bibliographically approved
    5. Tuneable Peak Deformations in Chiral Liquid Chromatography
    Open this publication in new window or tab >>Tuneable Peak Deformations in Chiral Liquid Chromatography
    2007 (English)In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 79, p. 5838-5847Article in journal (Refereed) Published
    National Category
    Analytical Chemistry Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-95293 (URN)10.1021/ac062330t (DOI)000248437700058 ()
    Available from: 2006-12-22 Created: 2006-12-22 Last updated: 2018-01-23Bibliographically approved
    6. Analytical Characterisation of Chiral Drug-Protein Interactions: A Comparison between the Optical Biosensor (SPR) Assay and the HPLC Perturbation Method
    Open this publication in new window or tab >>Analytical Characterisation of Chiral Drug-Protein Interactions: A Comparison between the Optical Biosensor (SPR) Assay and the HPLC Perturbation Method
    2006 In: Analytical Chemistry, ISSN 10.1021/ac051802l, Vol. 78, no 5, p. 1682-1689Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-95294 (URN)
    Available from: 2006-12-22 Created: 2006-12-22Bibliographically approved
  • 4.
    Arnell, Robert
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Ferraz, Natalia
    Fornstedt, Torgny
    Analytical Characterisation of Chiral Drug-Protein Interactions: A Comparison between the Optical Biosensor (SPR) Assay and the HPLC Perturbation Method2006In: Analytical Chemistry, ISSN 10.1021/ac051802l, Vol. 78, no 5, p. 1682-1689Article in journal (Refereed)
  • 5.
    Arnell, Robert
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology.
    Ferraz, Natalia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology.
    Fornstedt, Torgny
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology.
    Analytical Characterization of Chiral Drug-Protein Interactions: Comparison between the Optical Biosensor (Surface Plasmon Resonance) Assay and the HPLC Perturbation Method2006In: Analytical Chemistry, Vol. 78, no 5, p. 1682-1689Article in journal (Refereed)
    Abstract [en]

    Two modern, fundamentally different methods were used for a detailed investigation of enantioselective drug-protein interactions, a surface plasmon resonance (SPR)-based Biacore 2000 biosensor assay and the previously validated HPLC perturbation method (HPLC-PM). This is the first time SPR has been used for this purpose. The fundamental features of the two methods were investigated, and the consequences for operation and data evaluation were addressed. With HPLC-PM, chiral data could be obtained directly from the racemic mixture, whereas a separate analysis of each pure enantiomer was required to obtain chiral data with SPR. It was shown that if chirality is not attributed in the SPR analysis, misleading average racemic binding constants will be obtained. Both drug and protein consumption were considerably higher with HPLC-PM. HPLC-PM was found to be best suited for measurements of weak affinity interactions, whereas the SPR method was best for strong interactions. With both methods, the presence of DMSO in the samples severely affected the interactions, introducing errors. The binding of the -blockers alprenolol and propranolol to Cel7a cellulase was used as a model system. These methods gave results that agreed quite well qualitatively, but considerable quantitative deviations were sometimes obtained.

  • 6.
    Arnell, Robert
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Fornstedt, Torgny
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Validation of the Tracer-Pulse Method for Multi-Component Liquid Chromatography. A Classical Paradox Revisited2006In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 78, no 13, p. 4615-4623Article in journal (Refereed)
    Abstract [en]

    The tracer-pulse method was extended and validated for the determination of multicomponent adsorption isotherms in liquid chromatography. Competitive adsorption isotherms can be determined for any number of solutes, up to the column resolution limit. The basic principle is to equilibrate the column with an eluent containing a mixture of the solutes and then measure the migration velocity of each of them through the column. It is easy to calculate the stationary phase concentrations from these velocities, given the eluent composition. As in frontal analysis, real competitive isotherm data are measured using this method, unlike other methods, which only produce parametric estimates. The method was used to measure the binary isotherms of beta-blockers on a Kromasil C8 column. The data were fitted to competitive bi-Langmuir adsorption isotherm functions and was found to agree well with the results of frontal analysis and the perturbation method. Computer simulations based on the isotherm parameters were performed and displayed very good agreement with the experimental chromatograms. An intriguing and seemingly paradoxical property is visualized and discussed: the fact that the injected molecules are not found in the detected peaks.

  • 7.
    Arnell, Robert
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology.
    Forssén, Patrik
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing.
    Fornstedt, Torgny
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology.
    Accurate and rapid estimation of adsorption isotherms in liquid chromatography using the inverse method on plateaus2005In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1099, p. 167-174Article in journal (Refereed)
  • 8.
    Atthoff, Björn
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Polymer Chemistry.
    Nederberg, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Polymer Chemistry.
    Söderberg, Lennart
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Hilborn, Jöns
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Polymer Chemistry.
    Bowden, Tim
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Polymer Chemistry.
    Synthetic Biodegradable Ionomers that Engulf, Store, and Deliver Intact Proteins2006In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 7, no 8, p. 2401-2406Article in journal (Refereed)
    Abstract [en]

    Telechelic anionic and cationic biodegradable ionomers capable of loading, storing, and releasing proteins are presented. Two different ionomers have been synthesized with either anionic or cationic end groups. The reaction was done quantitatively as shown by 1H NMR. The swelling properties of the hydrophobic poly(trimethylene carbonate) polymer are contributed to the ionic end groups that display hydrophilic properties. Depending on the molecular weight of the ionomer, and also on the ionic charge, the materials swell differently in water, from ~50% for Mw = 12 000 g/mol to ~500% when dealing with 2000 g/mol. The high swelling led us to believe that it would be possible to load and release proteins preferably in a still active form. As models, two different proteins were chosen: hemoglobin and cytochrome c. The swelling and release study shows that both ionomers possess the capability to adsorb and later release the proteins with retained structure. Release measurements from both the swollen and dried states have been evaluated with similar results, showing that the dried state seems to release a little bit less than the swollen one. These kinds of materials should be interesting for a wide variety of applications where drug and protein release is wanted, as well as in applications such as protein separation media.

  • 9.
    Barinov, S.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Rustichelli, F.
    Orlovskii, V.P.
    Lodini, A.
    Oscarsson, S.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Firstov, S.A.
    Tumanov, S.V., Millet, P.
    Rosengren, Å.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Influence of fluorapatite minor additions on behavior of hydroxyapatite Ceramics2004In: J. of Materials Science: Materials in Medicine, Vol. 15, p. 291-296Article in journal (Refereed)
    Abstract [en]

    Fluorinated hydroxyapatite is known to be less soluble by body fluids, resulting in enhanced resistance to biodegradation in vivo conditions, as compared to the pure hydroxyapatite ceramics. The present work was aimed at the investigation of the effect of

  • 10.
    Bergkvist, M.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Carlsson, J.
    Oscarsson, S.
    Tertiary Structure of Fibronectin Adsorbed to Hydrophobic/ Hydrophilic Surfaces Studied with AFM2003In: J. Biomed. Mater. Res., Vol. 64, p. 349-Article in journal (Refereed)
  • 11.
    Bergkvist, Magnus
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Orientation and Conformation of Single Macromolecules on Unmodified and Functionalized Surfaces2002Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis methods for investigation of orientation and conformation of individual macromolecules on surfaces are presented as well as novel methods for functionalization of silicon chips with the possibility to get an ordered immobilization of antibodies.

    Two novel methods are presented which makes it possible to investigate the orientation of individual macromolecules on different kinds of surfaces with AFM. One is based on threshold patterning where, depending on substrate, side- and end-on adsorbed immunoglobulin molecules could be detected. The other method is using the principle of site-specific ligands where the orientation of proteins adsorbed to various surfaces was evaluated. By measuring the increase in protein volume of the formed protein-ligand complexes with AFM, the amount of protein having an orientation that allows binding can be estimated.

    The influence of surface chemistry on protein structure was examined using human serum fibronectin adsorbed to hydrophilic and hydrophobic surfaces, where a major difference in structure were seen depending on surface properties.

    In addition, methods for surface functionalization have been developed which are suitable for immobilization of macromolecules and for basic studies of macromolecule/surface interactions at the nanometer scale. In an effort to immobilize protein in a specific orientation that could be studied with AFM, a new method for preparing reactive disulfides based upon a mixed reaction with 2,2’-dipyridyldisulfide and 2-thiopyridone to a mercapto-silanized silica surface was presented. The possibility to covalently bind proteins to this surface was examined, using beta-galactosidase and Fab’-fragments of IgG.

    List of papers
    1. TM-AFM Threshold Analysis of Macromolecular Orientation: A Study of the Orientation of IgG and IgE on Mica Surfaces
    Open this publication in new window or tab >>TM-AFM Threshold Analysis of Macromolecular Orientation: A Study of the Orientation of IgG and IgE on Mica Surfaces
    1998 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 206, no 2, p. 475-481Article in journal (Refereed) Published
    Abstract [en]

    Adsorption and orientation properties of two different types of immunoglobulin molecules on derivatized and native mica surfaces were investigated using TM-AFM. The analyses included height measurements at two different pH values and a new technique, presented here as threshold analysis, which displays the outer mantle shape of an adsorbed protein. A major difference in preferential orientation is observed upon comparing the adsorption of the two proteins onto the different surfaces. The characteristics of both the adsorbed immunoglobulin and the surface are important for any preferential orientation of the adsorbed protein.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-89709 (URN)10.1006/jcis.1998.5630 (DOI)9756659 (Scopus ID)
    Available from: 2002-03-19 Created: 2002-03-19 Last updated: 2017-12-14Bibliographically approved
    2. A method for studying protein orientation with atomic force microscopy using relative protein volumes
    Open this publication in new window or tab >>A method for studying protein orientation with atomic force microscopy using relative protein volumes
    2001 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 105, no 10, p. 2062-2069Article in journal (Refereed) Published
    Abstract [en]

    A method for studying protein orientation is described, in which the relative volumes of single proteins and single molecule complexes are measured using atomic force microscopy (AFM). Site-specific ligands are used as “probes” to bind to surface adsorbed proteins. The quantity of formed complexes gives an estimate of the amount of protein oriented in such a way as to allow ligand binding. The volume distribution for single proteins adsorbed to a surface was calculated and fitted to a Gaussian function. This volume distribution was used to localize the same proteins on surfaces with protein−ligand complexes, thus rendering it possible to find the amount of complex formed. Two model systems were used: one with two different mouse monoclonal antibodies of IgG1 type (mAb's against human serum transferrin, hST) adsorbed on silicon surfaces, and one with hST adsorbed to unmodified mica and aminated mica. The adsorbed proteins were allowed to react with a site-specific ligand, which binds to a defined region of the adsorbed protein (hST in the case of adsorbed mAb and lectin in the case of adsorbed hST). A great difference in ligand binding was found between the two antibodies adsorbed to the same type of surface as well as between hST adsorbed to different surfaces. This differance can be attributed to different orientation of the proteins on the surface. The general approach of this method suggests that it can be used for almost any site-specific molecule, either for surface orientation studies or studies where single molecule interactions need to be investigated.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-89710 (URN)10.1021/jp003957x (DOI)
    Available from: 2002-03-19 Created: 2002-03-19 Last updated: 2017-12-14Bibliographically approved
    3. Surface dependant conformations of human plasma fibronectin adsorbed to silica, mica and hydrophobic surfaces, studied with Atomic Force Microscopy
    Open this publication in new window or tab >>Surface dependant conformations of human plasma fibronectin adsorbed to silica, mica and hydrophobic surfaces, studied with Atomic Force Microscopy
    In: J. Biomed. Mater. Res.Article in journal (Refereed) Submitted
    Identifiers
    urn:nbn:se:uu:diva-89711 (URN)
    Available from: 2002-03-19 Created: 2002-03-19Bibliographically approved
    4. A Novel Method for Preparation of Disulfides on Silicon
    Open this publication in new window or tab >>A Novel Method for Preparation of Disulfides on Silicon
    Show others...
    2001 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 17, no 20, p. 6056-6058Article in journal (Refereed) Published
    Abstract [en]

    This work describes an efficient novel method to incorporate reactive disulfide bonds onto a silica surface under mild reaction conditions. The reactive thiol groups introduced onto the silicon surface in the first reaction step will be oxidized but easily converted into highly reactive thiopyridyl groups, which can therefore easily be utilized for further organic synthesis involving thiol-containing molecules. This is done in a way that yields approximately a monolayer of reactant on the surface, thereby not adding to the roughness of the surface, of special importance, for instance, for single molecule interaction studies.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-89712 (URN)10.1021/la0155092 (DOI)
    Available from: 2002-03-19 Created: 2002-03-19 Last updated: 2017-12-14Bibliographically approved
    5. Atomic Force Microscopy studies of proteins immobilized on silica by thiol-disulfide exchange
    Open this publication in new window or tab >>Atomic Force Microscopy studies of proteins immobilized on silica by thiol-disulfide exchange
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:uu:diva-89713 (URN)
    Available from: 2002-03-19 Created: 2002-03-19 Last updated: 2010-01-13Bibliographically approved
  • 12.
    Bergkvist, Magnus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Carlsson, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Karlsson, Torbjörn
    Oscarsson, Sven
    TM-AFM Threshold Analysis of Macromolecular Orientation: A Study of the Orientation of IgG and IgE on Mica Surfaces1998In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 206, no 2, p. 475-481Article in journal (Refereed)
    Abstract [en]

    Adsorption and orientation properties of two different types of immunoglobulin molecules on derivatized and native mica surfaces were investigated using TM-AFM. The analyses included height measurements at two different pH values and a new technique, presented here as threshold analysis, which displays the outer mantle shape of an adsorbed protein. A major difference in preferential orientation is observed upon comparing the adsorption of the two proteins onto the different surfaces. The characteristics of both the adsorbed immunoglobulin and the surface are important for any preferential orientation of the adsorbed protein.

  • 13.
    Bergkvist, Magnus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Carlsson, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Oscarsson, Sven
    A method for studying protein orientation with atomic force microscopy using relative protein volumes2001In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 105, no 10, p. 2062-2069Article in journal (Refereed)
    Abstract [en]

    A method for studying protein orientation is described, in which the relative volumes of single proteins and single molecule complexes are measured using atomic force microscopy (AFM). Site-specific ligands are used as “probes” to bind to surface adsorbed proteins. The quantity of formed complexes gives an estimate of the amount of protein oriented in such a way as to allow ligand binding. The volume distribution for single proteins adsorbed to a surface was calculated and fitted to a Gaussian function. This volume distribution was used to localize the same proteins on surfaces with protein−ligand complexes, thus rendering it possible to find the amount of complex formed. Two model systems were used: one with two different mouse monoclonal antibodies of IgG1 type (mAb's against human serum transferrin, hST) adsorbed on silicon surfaces, and one with hST adsorbed to unmodified mica and aminated mica. The adsorbed proteins were allowed to react with a site-specific ligand, which binds to a defined region of the adsorbed protein (hST in the case of adsorbed mAb and lectin in the case of adsorbed hST). A great difference in ligand binding was found between the two antibodies adsorbed to the same type of surface as well as between hST adsorbed to different surfaces. This differance can be attributed to different orientation of the proteins on the surface. The general approach of this method suggests that it can be used for almost any site-specific molecule, either for surface orientation studies or studies where single molecule interactions need to be investigated.

  • 14.
    Bergkvist, Magnus
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Carlsson, Jan
    Oscarsson, Sven
    Surface dependant conformations of human plasma fibronectin adsorbed to silica, mica and hydrophobic surfaces, studied with Atomic Force MicroscopyIn: J. Biomed. Mater. Res.Article in journal (Refereed)
  • 15.
    Bergkvist, Magnus
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Ledung, Greger
    Carlsson, Jan
    Oscarsson, Sven
    Atomic Force Microscopy studies of proteins immobilized on silica by thiol-disulfide exchangeManuscript (Other academic)
  • 16. Bjursten, LM
    et al.
    Rosengren, A
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Materials Chemistry, Polymer Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Marcolongo, M
    Johansson, JA
    Hilborn, Jöns
    Department of Materials Chemistry, Polymer Chemistry. polymerkemi.
    Foreign body reaction is elicited by mechanical properties of implanted materials2003In: Faseb Journal, Vol. 17, no 5, p. A1197-Article in journal (Refereed)
  • 17.
    Bohner, K.
    et al.
    Uppsala University, Centre for Surface Biotechnology.
    Ring, T. A.
    Rapoport, Natalya
    Caldwell, K. D.
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Fibrinogen adsorption by latex particles coated with various amounts of PEO/PPO/PEO triblock copolymer2002In: J. Biomater. Sci. Polymer Edition, Vol. 13, no 6, p. 733-746Article in journal (Refereed)
  • 18. Briggs, Ewan P
    et al.
    Walpole, Andrew R
    Wilshaw, Peter R
    Karlsson, Marjam
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Pålsgård, Eva
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Formation of highly adherent nano-porous alumina on Ti-based substrates: a novel bone implant coating2004In: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 15, no 9, p. 1021-1029Article in journal (Refereed)
    Abstract [en]

    Thin, nano-porous, highly adherent layers of anodised aluminium formed on the surface of titanium alloys are being developed as coatings for metallic surgical implants. The layers are formed by anodisation of a 1–5 m thick layer of aluminium which has been deposited on substrate material by electron beam evaporation. The surface ceramic layer so produced is alumina with 6–8 wt % phosphate ions and contains 5×108 cm–2 pores with a 160 nm average diameter, running perpendicular to the surface. Mechanical testing showed the coatings'' shear and tensile strength to be at least 20 and 10 MPa, respectively. Initial cell/material studies show promising cellular response to the nano-porous alumina. A normal osteoblastic growth pattern with cell number increasing from day 1 to 21 was shown, with slightly higher proliferative activity on the nano-porous alumina compared to the Thermanox control. Scanning electron microscopy (SEM) examination of the cells on the porous alumina membrane showed normal osteoblast morphology. Flattened cells with filopodia attaching to the pores and good coverage were also observed. In addition, the pore structure produced in these ceramic coatings is expected to be suitable for loading with bioactive material to enhance further their biological properties.

  • 19.
    Buijs, J.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Ramström, M.
    Danfelter, M.
    Larsericsdotter, H.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Håkansson, P.
    Oscarsson, S.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Localized changes in the structural stability of myoglobin upon adsorption onto silica particles, as studied with hydrogen/ deuterium exchange mass spectrometry2003In: Journal of Colloid and Interface Science, Vol. 263, no 2, p. 441-448Article in journal (Refereed)
    Abstract [en]

    A new method is presented for monitoring the conformational stability of various parts of a protein that is physically adsorbed onto nanometer-sized silica particles. The method employs hydrogen/deuterium (H/D) exchange of amide hydrogens, a process that is extremely sensitive to structural features of proteins. The resulting mass increase is analyzed with Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. Higher structural specificity is obtained by enzymatically cleaving the adsorbed proteins prior to mass spectrometric analysis. The mass increases of four peptic fragments of myoglobin are followed as a function of the H/D exchange time. The four peptic fragments cover 90% of the myoglobin structure. Two of the peptic fragments, located in the middle of the myoglobin sequence and close to the heme group, do not show any adsorption-induced changes in their structural stability, whereas the more stable C- and N-terminal fragments are destabilized. Interestingly, for the N-terminal fragment, comprising residues 1–29, two distinct and equally large conformational populations are observed. One of these populations has a stability similar to that in solution (−23 kJ/mol), whereas the other population is highly destabilized upon adsorption (−11 kJ/mol).

  • 20.
    Caldwell, Karin
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Wahlund, K.-G.
    Field-Flow Fractionation in Protein Analysis2005In: Methods for Structural Analysis of Protein Pharmaceuticals, 2005Chapter in book (Refereed)
  • 21.
    Elfwing, A.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    LeMarc, Y.
    Baranyi, J.
    Ballagi, A
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Observing Growth and Division of Large Numbers of Individual Bacteria by Image Analysis2004In: Applied and Environmental Microbiology, Vol. 70, no 2, p. 675-678Article in journal (Refereed)
    Abstract [en]

    We describe a method that enabled us to observe large numbers of individual bacterial cells during a long period of cell growth and proliferation. We designed a flow chamber in which the cells attached to a transparent solid surface. The flow chamber was mounted on a microscope equipped with a digital camera. The shear force of the flow removed the daughter cells, making it possible to monitor the consecutive divisions of a single cell. In this way, kinetic parameters and their distributions, as well as some physiological characteristics of the bacteria, could be analyzed based on more than 1,000 single-cell observations. The method which we developed enabled us to study the history effect on the distribution of the lag times of single cells.

  • 22.
    Feiler, Adam
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Physical and Analytical Chemistry, Surface Biotechnology.
    Jenkins, Paul
    Rutland, Mark W
    Effect of relative humidity on adhesion and frictional properties of micro- and nano-scopic contacts2005In: Journal of Adhesion Science and Technology, ISSN 0169-4243 (Paper) 1568-5616 (Online), Vol. 19, no 3-5, p. 165-179Article in journal (Refereed)
    Abstract [en]

    The effect of relative humidity (RH) on the interactions of AFM tips and colloidal probes with hydrophilic silica substrates is investigated. Both friction and adhesion are studied. For the case of a colloidal probe the interaction is characteristic of a multiasperity contact, the adhesion increased with increasing RH and above a certain threshold relative humidity a large increase in adhesion was measured. This behaviour is explained in terms of a recent model where the Kelvin radius of the condensate becomes larger than some characteristic roughness on the surface. The interaction between the tip and the substrate also exhibited an increase in adhesion above a threshold RH although the increase was much less marked than with the colloid probe. The friction decreased with increasing humidity for both tip and colloid probe although the friction force was much less sensitive than adhesion to changes in RH. Stick-slip behaviour was observed between tip and substrate for all humidities at high loads, but only at the lowest RH (about 5%) it was observed at all loads. At higher humidity the behaviour became increasingly continuum on the experimental timescale, presumably due to viscous contributions from the water. Stick-slip was not observed for the colloidal probe friction measurements.

  • 23.
    Fornstedt, Torgny
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Guichon, Georges
    Influence of the solution pH on the interaction mechanisms between the molecules of the (R)- and (S)-enantiomers of a few beta-receptor blocking agents and those of cellobiohydrolase I (CBH I)2003In: Thermochimica Acta, Vol. 398, p. 73-Article in journal (Refereed)
  • 24.
    Fornstedt, Torgny
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology.
    Götmar, Gustav
    Andersson, Marie
    Guiochon, Georges
    Dependence on the Mobile Phase pH of the Adsorption Behavior of Propranolol Enantiomers on a Cellulase Protein Used as the Chiral Selector1999In: Journal of the American Chemical Society, Vol. 121, p. 1164-1174Article in journal (Refereed)
  • 25.
    Forssén, Patrik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Lindholm, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Fornstedt, Torgny
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Theoretical and experimental study of binary perturbation peaks with focus on peculiar retention behaviour and vanishing peaks in chiral liquid chromatography2003In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 991, p. 31-45Article in journal (Refereed)
  • 26. Franco Fraguas, Laura
    et al.
    Carlsson, Jan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Lönnberg, Maria
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Lectin Affinity Chromatography as a Tool to Differentiate Erythropoietin (EPO) and its analogues: abstract2004In: Trends in Glycoscience and Glycotechnology, Vol. 16, p. 63-Article in journal (Refereed)
  • 27.
    Fromell, K.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Huang, S.-C.
    Caldwell, K.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Scanning Calorimetry in Probing the Structural Stability of Proteins at Interfaces2003Chapter in book (Refereed)
  • 28.
    Fromell, Karin
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Physical and Analytical Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Andersson, Margaretha
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Physical and Analytical Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Elihn, Karine
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Physical and Analytical Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Caldwell, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Physical and Analytical Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Nanoparticle decorated surfaces with potential use in glycosylation analysis2005In: Colloids and Surfaces B: Biointerfaces, Vol. 46, p. 84–91-Article in journal (Refereed)
    Abstract [en]

    A majority of all biologically active proteins are glycosylated and various diseases have proven to correlate with alterations in protein glycosylation. Sensitive identification of different glycoprotein glycoforms is therefore of great diagnostic value. Here we describe a method with potential for glycoprotein profiling, based on lectins as capture probes immobilized on particulate substrates in the nm-range. The nanoparticles present high concentrations of attachment sites for specific ligands and cause minimal steric hindrance to binding. In the present model study the mannose-binding lectin ConA has been coupled to polystyrene nanoparticles via a poly(ethyleneoxide) linker which protects the protein conformation and activity and prevents unspecific protein adsorption. The ConA-coated particles are accommodated at different spots on the analytical surface via oligonucleotide linkage. This attachment, which relies on the hybridization of complementary oligonucleotides, allows firm fixation of the particles at specific positions. The ConA attached to the particles has retained conformation and activity and binds selectively to a series of different glycoproteins. The results indicate the potential for using a multi-lectin nanoparticle array in glycoprotein mapping.

  • 29.
    Gottschalk, Ingo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry.
    Gustavsson, Per-Erik
    Ersson, Bo
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry.
    Lundahl, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Improved lectin-mediated immobilization of human red blood cells in superporous agarose beads2003In: Journal of chromatography. B, ISSN 1570-0232, E-ISSN 1873-376X, Vol. 784, no 1, p. 203-208Article in journal (Refereed)
    Abstract [en]

    A new type of agarose bead, superporous agarose, was used as a gel support for immobilization of human red blood cells (RBCs) mediated by wheat germ lectin. The number of immobilized cells was similar to that obtained with commercial wheat germ lectin–agarose but the cell stability appeared to be superior. This allowed improved frontal affinity chromatographic analyses of cytochalasin B (CB)-binding to the glucose transporter GLUT1 which established a ratio of one CB-binding site per GLUT1 dimer for both plain RBCs or those treated with different poly amino acids. The measured dissociation constants, 70±14 nM for CB and 12±3 mM for glucose binding to GLUT1, are similar to those reported earlier.

  • 30. Gu, M.
    et al.
    Su, Z.-G.
    Janson, Jan-Christer
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    The Separation of Polyphenols by Isocratic Hydrogen Bond Adsorption Chromatography on a Cross-Linked 12% Agarose Gel2006In: Chromatographia, ISSN 0009-5893, E-ISSN 1612-1112, Vol. 64, no 5-6, p. 247-253Article in journal (Refereed)
    Abstract [en]

    The highly cross-linked 12% agarose gel, Superose™ 12 HR 10/30 is shown to possess hydrogen bond acceptor properties suitable for the separation of polyphenolic solutes such as phenolic acids, flavonols and flavonoids. The separation is achieved isocratically in the presence of solvent mixtures of acetic acid and ethanol. The extent of hydrogen bond adsorption is reviewed based on data obtained from the elution behaviour of a variety of simple polyphenolic solutes including dihydroxybenzoic acids.

  • 31.
    Gullberg, Elisabet
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Keita, Åsa V.
    Salim, Sa'ad Y.
    Andersson, Margaretha
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Caldwell, Karin D.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
    Söderholm, Johan D.
    Artursson, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Identification of Cell Adhesion Molecules in the Human Follicle-Associated Epithelium That Improve Nanoparticle Uptake into the Peyer's Patches2006In: Journal of Pharmacology and Experimental Therapeutics, ISSN 0022-3565, E-ISSN 1521-0103, Vol. 319, no 2, p. 632-639Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to identify cell adhesion molecules that could serve as targets of the human follicle-associated epithelium (FAE) overlying Peyer's patches and to assess nanoparticle uptake levels across this epithelium. We first studied the expression of the mouse M-cell marker beta(1)-integrin and used a model of human FAE derived from intestinal epithelial Caco-2 cells and Raji B-cells to identify additional potential targets by cDNA array. The protein expression of potential targets in the model FAE and in human ileal FAE tissues was quantified by immunofluorescence. Integrin targeting was studied by investigating the transport of Arg-Gly-Asp (RGD)-coated (integrin- binding), Arg-Gly-Glu (RGE)-coated (nonintegrin-binding), and uncoated nanoparticles across ileal specimens mounted in Ussing chambers. Both beta(1)-integrin and the cell adhesion molecule CD9 were more abundantly expressed in the model and human FAE compared with the Caco-2 control cells or villus epithelium (VE). Uncoated nanoparticles were not taken up across either FAE or VE. General integrin targeting with RGD improved the nanoparticle transport dramatically across the FAE and to a lower extent across the VE. Compared with RGE, RGD improved transport 4-fold across the FAE. There was no difference in the transport of RGD- and RGE-coated nanoparticles across the VE. In conclusion, beta(1)-integrin and CD9 were identified as targets in human FAE. The difference in RGD- and RGE-mediated transport across the FAE, but not the VE, suggests that a specific integrin interaction was the dominating mechanism for improved nanoparticle uptake across the FAE., whereas charge interaction contributed substantially to the improved VE uptake.

  • 32.
    Gunnarsson, Klas
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology. Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Roy, Pierre E.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology. Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Felton, Solveig
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology. Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Pihl, Johan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology. Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Svedlindh, Peter
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology. Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Berner, Simon
    Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology. Technology, Department of Engineering Sciences, Solid State Physics.
    Lidbaum, Hans
    Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology. Technology, Department of Engineering Sciences, Solid State Physics.
    Oscarsson, Sven
    Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology. Technology, Department of Engineering Sciences, Solid State Physics.
    Programmable Motion and Separation of Single Magnetic Particles on Patterned Magnetic Surfaces2005In: Advanced Materials, Vol. 17, no 14, p. 1730-1734Article in journal (Refereed)
  • 33.
    Götmar, G.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Stanley, B.
    Fornstedt, T.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Guichon, G.
    Heterogenous Adsorption of beta-blockers on Immobilised Cel7A and Adsorption Energy Distribution of Two Enantiomers on a Chiral Phase2003In: Distribution Langmuir, Vol. 19, p. 6950-6956Article in journal (Refereed)
  • 34.
    Götmar, Gustav
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology, Centre for Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Albareda, Núria, Robinat
    Fornstedt, Torgny
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Investigation of the Heterogenous Adsorption Behavior of Selected Enantiomers on Immobilised alpha 1-acid glycoprotein2002In: Analytical Chemistry, Vol. 74, p. 2950-2959Article in journal (Refereed)
  • 35. Hajslová, J.
    et al.
    Schultzová, V.
    Slanina, P.
    Janné, K.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Department of Physical and Analytical Chemistry, Surface Biotechnology.
    Hellenäs, K.E.
    Andersson, Ch.
    Quality of organically and conventionally grown potatoes: Four-year study of micronutrients, metals, secondary metabolites, enzymic browning and organoleptic properties2005In: Food Additives & Contaminants, Vol. 22, no 6, p. 514-534Article in journal (Refereed)
    Abstract [en]

    The quality of potatoes from organic and conventional farming was investigated in this study. Tubers of eight potato varieties, organically and conventionally produced at one or two geographical sites in controlled field trials, were collected in four consecutive harvests from 1996–1999. The parameters analysed included nitrate, trace elements (As, Cd, Co, Cu, Fe, Hg, Mn, Ni, Pb, Se, Zn), vitamin C, potato glycoalkaloids, as well as chlorogenic acid, polyphenol oxidase and rate of tuber enzymic browning. The results indicated lower nitrate content and higher vitamin C and chlorogenic acid content to be the parameters most consistently differentiating organically from conventionally produced potatoes. Elevated concentrations of glycoalkaloids were also observed throughout the experiments in some potato varieties grown in organic farming systems. Principal component analysis (PCA) of the analytical and other data using three PCs confirmed a good separation between the organically and conventionally produced potatoes when studied in single crop years. However, score-plots (objects) and loading-plots (variables) of pooled results from the consecutive harvests showed that between the years’ changes and also variety as well as geographical variations are equally or more important factors determining the quality of potatoes than the farming system. Further studies of various marker compounds of potato quality related to the organic or conventional farming systems should be performed before unbiased information can be given to the consumers.

  • 36.
    Han, Xiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Pathmasiri, Wimal
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Bohlin, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Janson, Jan-Christer
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Isolation of high purity 1-[2′,4′-dihydroxy-3′,5′-di-(3″-methylbut-2″-enyl)-6′-methoxy] phenylethanone from Acronychia pedunculata (L.) Miq. by high-speed counter-current chromatography2004In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1022, no 1-2, p. 213-216Article in journal (Refereed)
    Abstract [en]

    Following an initial clean-up step on silica, high-speed counter-current chromatography (HSCCC) was used to purify an aryl ketone, 1-[2′,4′-dihydroxy-3′,5′-di-(3″-methylbut-2″-enyl)-6′-methoxy] phenylethanone from an extract of the stem bark of the shrub Acronychia pedunculata. The two-phase solvent system used was composed of n-heptane–ethyl acetate–methanol–water at an optimized volume ratio of 4:1:4:1 (v/v/v/v). Target compound (58.1 mg) with a purity of 98.9% was obtained after HSCCC of 183.5 mg sample with a purity of 35.7% recovered after the silica clean-up step. Identification of the target compound was performed by 1H NMR, 13C NMR, two-dimensional NMR and LC–electrospray ionization MS.

  • 37.
    Hardenborg, Emilia
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Zuberovic, Aida
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Ullsten, Sara
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Söderberg, Lennart
    Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Heldin, Eva
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Novel polyamine coating providing non-covalent deactivation and reversed electroosmotic flow of fused-silica capillaries for capillary electrophoresis2003In: J. of Chromatography A, no 1003, p. 217-221Article in journal (Refereed)
  • 38. He,, X.
    et al.
    T., Tan
    Janson, J.-C.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Purification of the isoflavonoid puerarin by adsorption chromatography on cross-linked 12% agarose2004In: J. Chromatogr. A, Vol. 1057, no 1-2, p. 95-100Article in journal (Refereed)
    Abstract [en]

    The isoflavonoid puerarin in extracts of the well-known traditional Chinese drug Radix puerariae (root of the plant Pueraria lobata) can be separated from other isoflavonoids by adsorption chromatography on the cross-linked 12% agarose gel Superose 12 equilibrated in distilled water. The adsorption is totally quenched by the addition of 50% acetic acid. The separation of the isoflavonoids is tentatively ascribed to interaction with the residues of the cross-linking reagents used in the manufacturing process of Superose 12. Thus, no useful separation can be achieved with non-cross-linked 12% agarose gel media. Symmetric elution profiles at high sample loadings (16 mg on a 24 ml column) suggest linear adsorption isotherms for the isoflavonoids.

  • 39. He, X.
    et al.
    Tan, B.
    Xu, B.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Janson, J.-C.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Separation and purification of puerarin using beta-cyclodextrin-coupled agarose gel media2004In: J. Chromatogr. A, Vol. 1022, no 1-2, p. 77-82Article in journal (Refereed)
    Abstract [en]

    The isoflavonoid puerarin, a well-known traditional Chinese drug, has been purified in one step from an extract of Radix puerariae (root of the plant Pueraria lobata) by adsorption chromatography on an epichlorohydrin polymerized beta-cyclodextrin ligand coupled to brominated allyl-group substituted Sepharose HP. Acetic acid (10%) was used as the mobile phase and the optimum loading capacity was around 1.2 mg crude extract/ml packed gel. The purity of the collected puerarin was about 98% with a recovery of about 62%.

  • 40.
    He, X.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Tan, T.
    Janson, J.-C.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Purification of puerarin by beta-cyclodextrin coupled Superose 12 pg2003In: Chin. J. Chromatogr., Vol. 21, p. 610-Article in journal (Refereed)
    Abstract [en]

    Puerarin is a kind of Chinese traditional medicine, which has the good medical function to hypertension and angina. In this study puerarin was purified by low-pressure liquid chromatography. The experimental conditions, such as mobile phase, the stationar

  • 41. Heldtander Königsson, Malin
    et al.
    Ballagi, Andras
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Surface Biotechnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Jansson, Eva
    Johansson, Karl-Erik
    Detection of Renibacterium salmoninarum in tissue samples by sequence capture and fluorescent PCR based on the 16S rRNA gene2005In: Veterinary Microbiology, Vol. 105, no 3-4, p. 235-243Article in journal (Refereed)
    Abstract [en]

    The 16S rRNA genes from eight isolates of Renibacterium salmoninarum with different origins and dates of isolation were

    sequenced to evaluate the possibility to construct a diagnostic PCR system with target sites within this gene. The sequences were

    found to be identical but for one single position in one of the isolates, and two regions with an adequate number of nucleotide

    differences as compared to closely related species were identified. Species-specific fluorescent PCR primers complementary to

    these regions were constructed as well as oligonucleotides for DNA preparation by sequence capture. A mimic molecule was

    constructed to be used as an internal control. The PCR was specific and allowed the detection of DNA equivalent to 1–10 R.

    salmoninarum genomes per reaction. The DNA preparation with sequence capture and analysis by PCR with a mimic was found

    to be a reliable method for analysis of kidneys from fish with BKD. The amount of PCR inhibiting substances present in the

    tissue was reduced, and the relevant DNAwas concentrated in the capture step. Furthermore, the use of the mimic molecule in

    the system assured that false negative