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Hommel H. Explaining spin labelling results through a mean field model of cooperative polymer adsorption with excluded volume. Colloids Surf A Physicochem Eng Asp 2012. [DOI: 10.1016/j.colsurfa.2012.02.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Hommel H. Developments of the spin labelling study of polymers at interfaces. Adv Colloid Interface Sci 2008; 141:1-23. [PMID: 18353269 DOI: 10.1016/j.cis.2008.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 01/31/2008] [Accepted: 02/03/2008] [Indexed: 11/16/2022]
Abstract
The spin labelling method has been used in a large variety of situations, in the broad field of polymers at solid interfaces. The relevance of the method is confirmed on linear neutral chains of poly (ethylene oxide) (PEO) in well defined situations and compared with the simple theoretical calculations of a mean field theory or some scaling arguments. Both theories have their own strengths and weaknesses. Then the fact, that polymers at solid liquid interfaces are three components systems, is considered and successively the effect of varying the polymer architecture, the solid surface and the solvent is studied. In all these cases specific results are obtained by Electron Paramagnetic Resonance (EPR) showing the usefulness and the versatility of the method.
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Bertholon I, Hommel H, Labarre D, Vauthier C. Properties of polysaccharides grafted on nanoparticles investigated by EPR. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:5485-90. [PMID: 16732681 DOI: 10.1021/la060570y] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The in vivo fate of nanoparticles developed as drug delivery systems is influenced by the surface characteristics of the colloidal particles. In the present work, surface characteristics of a series of poly(isobutylcyanoacrylate) nanoparticles prepared by redox radical emulsion polymerization with polysaccharides of different molecular weight and nature were characterized by EPR. To this aim, a spin label was grafted on the polysaccharide chains after synthesis of the nanoparticles. The percentage of label showing fast movements was evaluated from EPR spectra which were analyzed according to the Kivelson theory. The results showed that mobility depended on temperature, type, and molecular weight of the polysaccharides. Differences between nanoparticles appeared with low-molecular-weight polysaccharides, while over a defined molecular weight which depended on the nature of the polysaccharide, the spin label behaved almost the same way in the different types of nanoparticles. Paradoxically, the percentage of fast moving label was the highest when linked to the shortest chitosan, which was the most rigid polysaccharide tested in this study. Thus, it was concluded that the apparent mobility of the polysaccharide evaluated by the EPR method depended on the capacity of the polysaccharide chains to fold making possible hydrophobic interactions between the label and the nanoparticle core. The transition between the unfolded-folded regiment depended on the molecular weight and on the nature of the polysaccharide. Results of this study may be useful to improve the understanding of the nanoparticle interactions with blood proteins and complement which in turn influence the in vivo fate of nanoparticles used as drug delivery systems.
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Affiliation(s)
- Isabelle Bertholon
- Laboratoire de Physico-chimie, Pharmacotechnie, Biopharmacie, UMR CNRS 8612, Faculté de Pharmacie, 5 rue Jean-Baptiste Clément, 92296 Châtenay-Malabry Cedex, France
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Lemarchand C, Gref R, Lesieur S, Hommel H, Vacher B, Besheer A, Maeder K, Couvreur P. Physico-chemical characterization of polysaccharide-coated nanoparticles. J Control Release 2005; 108:97-111. [PMID: 16169626 DOI: 10.1016/j.jconrel.2005.07.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Revised: 07/18/2005] [Accepted: 07/19/2005] [Indexed: 11/22/2022]
Abstract
A series of amphiphilic copolymers (PCL-DEX) made of poly(epsilon-caprolactone) (PCL) side chains grafted onto a dextran (DEX) backbone, was used to modify the surface of PCL nanoparticles. PCL-DEX nanoparticles were prepared by a technique derived from emulsion-solvent evaporation. The purpose of the present study was to investigate the DEX coating (quantification, conformation, mobility) in order to better understand particle surface-protein interactions. The DEX coating was deeply examined using different complementary methods: zeta potential measurement, specific degradation of the DEX shell by dextranase, energy-filtering transmission electron microscopy coupled to image-spectrum electron energy-loss spectroscopy, electronic paramagnetic resonance, high performance size exclusion chromatography as well as nonspecific bovine serum albumin adsorption. All our data together supported a core-shell structure of the nanoparticles, DEX moieties constituting the external coating. The amount of DEX located on the nanoparticle surface was estimated to 70%. The organisation of the shell including chains density and mobility was found to be dramatically influenced by DEX molar mass. The steric repulsion conferred by the presence of DEX at the surface of the nanoparticles decreased the adsorption of albumin. The nanoparticle-protein interaction was, however, greatly influenced by the polysaccharide conformation onto the surface.
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Affiliation(s)
- Caroline Lemarchand
- UMR CNRS 8612, School of Pharmacy, Châtenay Malabry, France; BioAlliance Pharma, Paris, France
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Schach R, Hommel H, Van Damme H, Dejardin P, Amsterdamsky C. Formation of weak polyelectrolyte multilayers studied by spin labeling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:3173-9. [PMID: 15875845 DOI: 10.1021/la030202j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Multilayers of alternately adsorbing poly(allylamine) (PAH) and poly(acrylic acid) (PAA) of opposite charges on silica have been studied by the spin labeling technique, as a function of pH. The two polyelectrolytes have been labeled independently by a nitroxide free radical. Its electron paramagnetic resonance spectrum is mainly sensitive to the local Brownian motion and shows lines typical of two different environments, namely, loops protruding in solution with a fast motion and trains adsorbed on the solid with a hindered motion. These two parts have been evaluated for each of the polymer layers separately, and the thickness of the coatings has been described more precisely by characterizing the four contributions existing, for example, for a bilayer. Complexation is demonstrated by the loss of loops and tails belonging to the first polyelectrolyte. The overall picture emerging from the data is explained in terms of compensation of charges and entropy of confinement.
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Affiliation(s)
- R Schach
- Laboratoire de Physico Chimie Structurale et Macromoleculaire, UMR 7615 CNRS, Ecole Supérieure de Physique et Chimie Industrielles, 75231 Paris Cedex 05, France
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Evaluation of the surface properties of dextran-coated poly(isobutylcyanoacrylate) nanoparticles by spin-labelling coupled with electron resonance spectroscopy. Colloid Polym Sci 2004. [DOI: 10.1007/s00396-003-1027-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Displacement of poly(ethylene oxide) adsorbed on silica by a nonionic surfactant studied by spin labeling. J SURFACTANTS DETERG 2002. [DOI: 10.1007/s11743-002-0236-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Leporini D, Zhu XX, Krause M, Jeschke G, Spiess HW. Probing Porous Polymer Resins by High-Field Electron Spin Resonance Spectroscopy. Macromolecules 2002. [DOI: 10.1021/ma011861a] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- D. Leporini
- Max Planck Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany; Dipartimento di Fisica “Enrico Fermi”, Universita' di Pisa, V.F.Buonarroti 2, I-56127 Pisa and INFM, UdR Pisa, Italy; and Département de chimie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montreal, QC, H3C 3J7 Canada
| | - X. X. Zhu
- Max Planck Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany; Dipartimento di Fisica “Enrico Fermi”, Universita' di Pisa, V.F.Buonarroti 2, I-56127 Pisa and INFM, UdR Pisa, Italy; and Département de chimie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montreal, QC, H3C 3J7 Canada
| | - M. Krause
- Max Planck Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany; Dipartimento di Fisica “Enrico Fermi”, Universita' di Pisa, V.F.Buonarroti 2, I-56127 Pisa and INFM, UdR Pisa, Italy; and Département de chimie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montreal, QC, H3C 3J7 Canada
| | - G. Jeschke
- Max Planck Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany; Dipartimento di Fisica “Enrico Fermi”, Universita' di Pisa, V.F.Buonarroti 2, I-56127 Pisa and INFM, UdR Pisa, Italy; and Département de chimie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montreal, QC, H3C 3J7 Canada
| | - H. W. Spiess
- Max Planck Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany; Dipartimento di Fisica “Enrico Fermi”, Universita' di Pisa, V.F.Buonarroti 2, I-56127 Pisa and INFM, UdR Pisa, Italy; and Département de chimie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montreal, QC, H3C 3J7 Canada
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Lin WY, Blum FD. Segmental dynamics of interfacial poly(methyl acrylate)-d(3) in composites by deuterium NMR spectroscopy. J Am Chem Soc 2001; 123:2032-7. [PMID: 11456826 DOI: 10.1021/ja003567o] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The interface in composite materials containing an ultrathin layer of poly(methyl acrylate)-d(3) (PMA-d(3)) on silica was studied using deuterium NMR. PMA-d(3) was deposited from solution at saturation coverage from toluene onto silica. The samples were dried and composite samples made by hot pressing the PMA-d(3)/silica samples with hydrogenated polystyrene (PS) and high (HMW) and low (LMW) molecular weight hydrogenated poly(methyl acrylate) (PMA) as the overlayer. The interfacial layers of PMA-d(3) were studied at the air-polymer-silica and polymer-polymer-silica interfaces using deuterium solid-state quadrupole-echo NMR and the results compared to those for the bulk polymer. It was found that for samples at the air-polymer-silica interface, some of the polymer segments in the surface sample had segmental mobility higher than that of the corresponding bulk PMA-d(3) sample at the same temperature. When overcoated with unlabeled polymer, the interfacial polymer at the polymer-polymer-silica interface showed reduced mobility due to the presence of the overlayer. The adsorbed PMA-d(3), in the composite samples, decreased in mobility in the order of LMW-PMA > HMW-PMA > PS. The PS sample caused the greatest reduction in the PMA-d(3) interfacial mobility. The order was consistent with the segmental mobilities of the polymers used for the overlayers. The lower the mobility of the polymer used for the overlayer, the more restricted were the polymer segments in the adsorbed PMA-d(3) layer.
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Affiliation(s)
- W Y Lin
- Department of Chemistry and Materials Research Center, University of Missouri-Rolla, Rolla, MO 65409-0010, USA
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Afif A, Chikhi M, Hommel H, Legrand A. Transport of a poly(ethylene oxide) solution through porous coated silica studied by spin labelling. POLYMER 2001. [DOI: 10.1016/s0032-3861(00)00547-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hommel H, Legrand A. Adsorption Properties of Silica towards Poly(Ethylene Oxide) as a Function of pH Studied by Spin-Labelling. Z PHYS CHEM 2001. [DOI: 10.1524/zpch.2001.215.5.593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Poly(ethylene oxide) chains spin labelled at their free end were adsorbed on amorphous silica and put into contact with buffers of different pH. The Electron Paramagnetic Resonance spectrum has a shape very sensitive to the Brownian motion of the free radical and exhibits composite lines characteristic of two environments: loops and tails protruding into solution with a fast motion; trains adsorbed on the solid surface with a restricted motion. Both components were analysed and the rotational correlation times and the two populations of labels were plotted as a function of pH and temperature. The chains are progressively desorbed as both increase due to the weaker hydrogen bounding with the reactive silanol groups present at the surface. Therefore a molecular picture of the chains at the interface can be gained.
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Porter CE, Blum FD. Thermal Characterization of PMMA Thin Films Using Modulated Differential Scanning Calorimetry. Macromolecules 2000. [DOI: 10.1021/ma000302l] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Crystal E. Porter
- Department of Chemistry and Materials Research Center, University of MissouriRolla, Rolla, Missouri 65409
| | - Frank D. Blum
- Department of Chemistry and Materials Research Center, University of MissouriRolla, Rolla, Missouri 65409
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Millot MC, Loehman L, Sébille B, Hommel H. Chromatographic properties of chiral stationary phases based on human serum albumin. Influence of the polymer sublayer. Chromatographia 1999. [DOI: 10.1007/bf02497297] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Afif A, Hommel H, Legrand AP, Bacquet M, Gailliez-Degremont E, Morcellet M. Molecular Conformation and Mobility of Polyamines Adsorbed on Silica Studied by Spin Labeling. J Colloid Interface Sci 1999; 211:304-314. [PMID: 10049546 DOI: 10.1006/jcis.1998.5989] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Poly(ethyleneimine) and poly(4-vinylpyridine) chains adsorbed on Nucleosil silica have been randomly labeled with nitroxide free radicals. The EPR signal is very sensitive to the molecular Brownian motion of the segments and shows generally at least two different environments: trains adsorbed on the surface with a restricted mobility, and loops and tails protruding into the solution with a fast motion. The rotational correlation times and the relative fraction of each population are given as functions of the coverage achieved and of the specific surface area of the silica for the samples in contact with methanol and sometimes water. The overall picture is consistent with a diffuse layer for the PEI and a more compact one with some heterogeneities for the P4VP. Copyright 1999 Academic Press.
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Affiliation(s)
- A Afif
- Laboratoire de Physique Quantique, URA 1428 C.N.R.S., E.S.P.C.I., 10, rue Vauquelin, Paris Cedex 05, 75231, France
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EPR Spectroscopy Analysis of Hydrophobically Modified Dextran-Coated Polystyrene. J Colloid Interface Sci 1998. [DOI: 10.1006/jcis.1997.5234] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Blum FD, Xu G, Liang M, Wade CG. Dynamics of Poly(vinyl acetate) in Bulk and on Silica. Macromolecules 1996. [DOI: 10.1021/ma960962j] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Frank D. Blum
- IBM Research Division, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099, and Department of Chemistry and Materials Research Center, University of MissouriRolla, Rolla, Missouri 65409-0010
| | - Gu Xu
- IBM Research Division, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099, and Department of Chemistry and Materials Research Center, University of MissouriRolla, Rolla, Missouri 65409-0010
| | - Minghua Liang
- IBM Research Division, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099, and Department of Chemistry and Materials Research Center, University of MissouriRolla, Rolla, Missouri 65409-0010
| | - Charles G. Wade
- IBM Research Division, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099, and Department of Chemistry and Materials Research Center, University of MissouriRolla, Rolla, Missouri 65409-0010
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Afif A, Hommel H, Legrand A. Thickness of a silica-tethered poly(ethylene oxide) layer in a very good solvent measured by spin-labelling. Colloids Surf A Physicochem Eng Asp 1996. [DOI: 10.1016/0927-7757(96)03517-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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From isolated coils to brushes of poly(ethylene oxide) grafted on silica: a spin-labelling study. Colloids Surf A Physicochem Eng Asp 1996. [DOI: 10.1016/0927-7757(96)03516-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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