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15 results on '"Frédéric Violleau"'

1. Characterization of Non-Derivatized Cellulose Samples by Size Exclusion Chromatography in Tetrabutylammonium Fluoride/Dimethylsulfoxide (TBAF/DMSO)

Author

Jérémy Rebière, Antoine Rouilly, Vanessa Durrieu, and Frédéric Violleau

Subjects
cellulose, molar mass, SEC analysis, conventional calibration, Organic chemistry, QD241-441
Abstract

This paper deals with the use of tetrabutylammonium fluoride/dimethylsulfoxide (TBAF/DMSO) to characterize the molar mass distribution of non-derivatized cellulosic samples by size exclusion chromatography (SEC). Different cellulose samples with various average degree of polymerization (DP) were first solubilized in this solvent system, with increasing TBAF rates, and then analyzed by SEC coupled to a refractive index detector (RID), using DMSO as mobile phase. The Molar Masses (MM) obtained by conventional calibration were then discussed and compared with suppliers’ data and MM determined by viscosimetry measurements. By this non-classic method, molar mass of low DP samples (Avicel® and cotton fibers) have been determined. For high DP samples (α-cellulose and Vitacel®), dissolution with TBAF concentration of 10 mg/mL involved elution of cellulose aggregates in the exclusion volume, related to an incomplete dissolution or the dilution of TBAF molecules in elution solvent, preventing the correct evaluation of their molar mass.

Published
2017
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2. Drug Release by Direct Jump from Poly(ethylene-glycol-b-ε-caprolactone) Nano-Vector to Cell Membrane

Author

Ugo Till, Laure Gibot, Anne-Françoise Mingotaud, Jérôme Ehrhart, Luc Wasungu, Christophe Mingotaud, Jean-Pierre Souchard, Alix Poinso, Marie-Pierre Rols, Frédéric Violleau, and Patricia Vicendo

Subjects
polymer micelles, pheophorbide-a, cellular penetration, uptake mechanism, Organic chemistry, QD241-441
Abstract

Drug delivery by nanovectors involves numerous processes, one of the most important being its release from the carrier. This point still remains unclear. The current work focuses on this point using poly(ethyleneglycol-b-ε-caprolactone) micelles containing either pheophorbide-a (Pheo-a) as a fluorescent probe and a phototoxic agent or fluorescent copolymers. This study showed that the cellular uptake and the phototoxicity of loaded Pheo-a are ten times higher than those of the free drug and revealed a very low cellular penetration of the fluorescence-labeled micelles. Neither loaded nor free Pheo-a displayed the same cellular localization as the labeled micelles. These results imply that the drug entered the cells without its carrier and probably without a disruption, as suggested by their stability in cell culture medium. These data allowed us to propose that Pheo-a directly migrates from the micelle to the cell without disruption of the vector. This mechanism will be discussed.

Published
2016
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3. Ozonized 2-hydroxypropyl-β-cyclodextrins as novel materials with oxidative and bactericidal properties

Author

Elsi, Haddad, Marielle, Pagès, Frédéric, Violleau, Olivier, Marsan, Marie-Hélène, Manero, Romain, Richard, and Jean-Philippe, Torré

Subjects
Cyclodextrins, Oxidative Stress, Polymers and Plastics, beta-Cyclodextrins, Organic Chemistry, Materials Chemistry, Oxidation-Reduction, 2-Hydroxypropyl-beta-cyclodextrin
Abstract

Ozonized (2-Hydroxypropyl)-β-cyclodextrins (Oz-HPbCDs) were produced by direct gas/solid reaction between gaseous ozone (O

Published
2022

4. Fractionation and characterization of polyphenolic compounds and macromolecules in red wine by asymmetrical flow field-flow fractionation

Author

Kevin Pascotto, Pascale Williams, Frédéric Violleau, Olivier Geffroy, Véronique Cheynier, Chimie Agro-Industrielle (CAI), Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Sciences Pour l'Oenologie (SPO), Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Région Occitanie , France, and Ecole d'ingénieurs Purpan, Toulouse, France

Subjects
Time Factors, Macromolecular Substances, [SDV]Life Sciences [q-bio], Wine, Fractionation, 010402 general chemistry, Polysaccharide, 01 natural sciences, Biochemistry, Analytical Chemistry, Colloid, Polysaccharides, [CHIM]Chemical Sciences, chemistry.chemical_classification, AF4, Chromatography, Chemistry, digestive, oral, and skin physiology, 010401 analytical chemistry, Organic Chemistry, Red wine, Polyphenols, food and beverages, Regenerated cellulose, General Medicine, Fractionation, Field Flow, 0104 chemical sciences, Molecular Weight, Proanthocyanidin, Polyphenol, Macromolecular complexes, Hydrodynamics, Tannins, Macromolecule
Abstract

Red wine is a complex matrix containing macromolecules such as condensed tannins and polysaccharides. Wine macromolecular components and their interactions have been reported to impact taste properties such as astringency but the colloidal systems formed in wine are not well known. A key prerequisite to characterize these systems is the ability to work under analytical conditions as close as possible to the colloid environment, preserving the sample structure and limiting the denaturation of macromolecular complexes. A method of Asymmetric Flow Field-Flow Fractionation (AF4) coupled with UV detection, multi-angle light scattering (MALS), and differential refractometer index (dRI) (AF4-UV-MALS-dRI) has been developed to analyse macromolecules, including tannins and polysaccharides, and macromolecular complexes, in red wine. This method separates objects according to their hydrodynamic radius and does not require calibration to determine molecular weight (Mw). AF4 can provide native separation of wine colloidal matter while working with simulated wine as mobile phase. The channel was equipped with a 350-µm spacer and the membrane made in regenerated cellulose had a cut-off of 5kDa. Different parameters of crossflow rate were investigated using a generic red wine to optimize separation conditions. Then, purified fractions of polysaccharides and tannins were analysed using the selected AF4 parameters. The comparison of the peaks obtained for these fractions and for the wine sample allowed us to determine the retention time associated with these macromolecules. The AF4 fractogram of wine was divided into four fractions. The first three were assigned to higher Mw tannins coeluted with lower Mw polysaccharides such as rhamnogalacturonan II (F1), to intermediate Mw polysaccharides (F2), and to higher Mw mannoproteins (F3) whereas the last fraction (F4) was not identified. Furthermore, our results have shown that AF4-UV-MALS-dRI could be an efficient technique to separate large size tannins as well as polysaccharides and macromolecular complexes.

Published
2020

5. Mechanistic Insights into Polyion Complex Associations

Author

Anne-Françoise Mingotaud, Debora Berti, Baptiste Amouroux, Jean-Daniel Marty, Frédéric Violleau, Michael Sztucki, Emanuela Di Cola, Giacomo Parigi, Claudio Luchinat, Stéphanie Balor, Christophe Mingotaud, Stéphane Gineste, Ugo Till, Barbara Lonetti, Interactions moléculaires et réactivité chimique et photochimique (IMRCP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), European Synchrotron Radiation Facility (ESRF), Laboratoire de Chimie des Polymères Organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC), Chimie Agro-Industrielle (CAI), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Centre de Microscopie Électronique Appliquée à la Biologie (CMEAB), Hôpital de Rangueil, CHU Toulouse [Toulouse]-CHU Toulouse [Toulouse]-Toulouse Réseau Imagerie-Genotoul ( TRI-Genotoul), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), This work was funded by the Midi-Pyrenees region and University of Toulouse, Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Université de Bordeaux (UB)-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Hôpital de Rangueil, CHU Toulouse [Toulouse]-CHU Toulouse [Toulouse], Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole d'Ingénieurs de Purpan - EIP (FRANCE), European Synchrotron Radiation Facility - ESRF (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Università degli Studi di Milano (ITALY), Organisation Européenne pour la Recherche Nucléaire - CERN (SWITZERLAND), Università degli Studi di Firenze (ITALY), Laboratoire de Chimie Agro-Industrielle - LCA (Toulouse, France), Centre de biologie Intégrative (Toulouse, france), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Fluides, Energie, Réacteurs, Matériaux et Transferts (FERMAT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), IDeAS - Interfaces Dynamiques et Assemblages Stimulables (IDeAS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT), Université de Bordeaux (UB)-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques (ENSIACET), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Toulouse Réseau Imagerie-Genotoul ( TRI-Genotoul), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Relaxometry, Polymers and Plastics, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Micelle, Light scattering, Inorganic Chemistry, Dynamic light scattering, Autre, Materials Chemistry, Polyion Complex, chemistry.chemical_classification, Chemistry, Small-angle X-ray scattering, Organic Chemistry, technology, industry, and agriculture, Polymer, biochemical phenomena, metabolism, and nutrition, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Ingénierie biomédicale, Chemical engineering, Macromolecules, [SDV.IB]Life Sciences [q-bio]/Bioengineering, Self-assembly, 0210 nano-technology, Drug carrier, [CHIM.OTHE]Chemical Sciences/Other
Abstract

International audience; Polyion complex (PIC) micelles formed from the electrostatic interaction between oppositely charged polymers have been studied for their promising applications in the biomedical field as drug carriers or vectors for gene delivery. In spite of their asset of possible high drug loading, their formation process remains poorly studied. In this work, we investigate the properties of a series of PICs based on poly(ethylene oxide-b-acrylic acid) (PEO–PAA)/dendrigraft poly(L-lysine) (DGL3), using PEO–PAA with different compositions and average molecular weights. For each PEO–PAA/DGL3 pair, the complexes were characterized as a function of the ratios between acid and amine moieties combining different techniques: dynamic light scattering (DLS), flow field-flow fractionation (FlFFF), small-angle X-ray scattering (SAXS), and relaxometry. The coupling of batch techniques, i.e., DLS, SAXS, and relaxometry, together with a soft separation technique like FlFFF enabled a finer analysis to elucidate subtle details of the association process and of the polydispersity of the complexes. We show that the formation of PICs is more complex than previously described. In particular, we demonstrate that PICs with stoichiometry 1:1 may form at low ratios provided that the acidic block is long enough to neutralize the cationic dendrigraft with few polymer chains. Moreover, in such conditions, PICs with stoichiometry 1:1 often coexist with free dendritic polymers and other associated complex species.

Published
2018

6. Frit inlet field-flow fractionation techniques for the characterization of polyion complex self-assemblies

Author

S. Kim Ratanathanawongs Williams, Baptiste Amouroux, Ugo Till, Christophe Mingotaud, Frédéric Violleau, Jean-Daniel Marty, Anne-Françoise Mingotaud, Mireille Gaucher, Stéphane Gineste, Carmen R.M. Bria, Barbara Lonetti, Interactions moléculaires et réactivité chimique et photochimique (IMRCP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS), Département Sciences Agronomiques et Agroalimentaires - EI Purpan, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole d'Ingénieurs de Purpan (INPT - EI Purpan), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Department of Chemistry, Laboratory for Advanced Separations Technologies, Colorado School of Mines, Chimie Agro-Industrielle (CAI), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), This work was funded by the Midi-Pyrenees region and University of Toulouse. National Science Foundation Grant CHE-1508827 for support., Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique - CNRS (FRANCE), Colorado School of Mines (USA), Ecole d'Ingénieurs de Purpan - EIP (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Laboratoire de Chimie Agro-Industrielle - LCA (Toulouse, France), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique de Toulouse - INPT (FRANCE), Ecole d'Ingénieurs de Purpan (INPT - EI Purpan), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Fluides, Energie, Réacteurs, Matériaux et Transferts (FERMAT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Ecole d'Ingénieurs de Purpan (INP - PURPAN), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Université de Toulouse (UT), and Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques (ENSIACET)

Subjects
[SDV.SA]Life Sciences [q-bio]/Agricultural sciences, Polymers, Proton Magnetic Resonance Spectroscopy, Acrylic Resins, Analytical chemistry, Fractionation, Chemical Fractionation, Sodium Chloride, 010402 general chemistry, Frit inlet flow field-flow fractionation, 01 natural sciences, Biochemistry, Dissociation (chemistry), Analytical Chemistry, chemistry.chemical_compound, polymère, Autre, Dynamic light scattering, Acrylic resin, Acrylic acid, Ions, chemistry.chemical_classification, Field flow fractionation, Chromatography, Elution, Lysine, 010401 analytical chemistry, Organic Chemistry, General Medicine, Polymer, Self-assembly, Dynamic Light Scattering, Fractionation, Field Flow, 0104 chemical sciences, Molecular Weight, Solutions, Refractometry, Bays, chemistry, Polyion complex micelles, visual_art, Chromatography, Gel, visual_art.visual_art_medium, [CHIM.OTHE]Chemical Sciences/Other, Flow field-flow fractionation, Sciences agricoles
Abstract

International audience; Polymer self-assemblies joining oppositely charged chains, known as polyion complexes (PICs), have been formed using poly(ethyleneoxide – b – acrylic acid)/poly(l-lysine), poly(ethyleneoxide-b-acrylic acid)/dendrigraft poly(l-lysine) and poly[(3-acrylamidopropyl) trimethylammonium chloride – b – N – isopropyl acrylamide]/poly(acrylic acid). The self-assemblies have been first characterized in batch by Dynamic Light Scattering. In a second step, their analysis by Flow Field-Flow Fractionation techniques (FlFFF) was examined. They were shown to be very sensitive to shearing, especially during the focus step of the fractionation, and this led to an incompatibility with asymmetrical FlFFF. On the other hand, Frit Inlet FlFFF proved to be very efficient to observe them, either in its symmetrical (FI-FlFFF) or asymmetrical version (FI-AsFlFFF). Conditions of elution were found to optimize the sample recovery in pure water. Spherical self-assemblies were detected, with a size range between 70–400nm depending on the polymers. Compared to batch DLS, FI-AsFlFFF clearly showed the presence of several populations in some cases. The influence of salt on poly(ethyleneoxide-b-acrylic acid) (PEO-PAA) 6000-3000/dendrigraft poly(l-lysine) (DGL 3) was also assessed in parallel in batch DLS and FI-AsFlFFF. Batch DLS revealed a first process of swelling of the self-assembly for low concentrations up to 0.8M followed by the dissociation. FI-AsFlFFF furthermore indicated a possible ejection of DGL3 from the PIC assembly for concentrations as low as 0.2M, which could not be observed in batch DLS.

Published
2017

7. Multimodal Dispersion of Nanoparticles: A Comprehensive Evaluation of Size Distribution with 9 Size Measurement Methods

Author

Frédéric Violleau, Christine Vauthier, Fanny Varenne, Ali Makky, Mireille Gaucher-Delmas, Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole d'Ingénieurs de Purpan - EIP (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université Paris-Sud 11 (FRANCE), Laboratoire de Chimie Agro-Industrielle - LCA (Toulouse, France), Institut Galien Paris-Sud (IGPS), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), École nationale supérieure agronomique de Toulouse [ENSAT], Ecole d'Ingénieurs de Purpan (INPT - EI Purpan), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, BPI-France: Projet Nice, and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Tunable resistive pulse sensing, Materials science, Analytical chemistry, Pharmaceutical Science, Nanoparticle tracking analysis, 02 engineering and technology, 010402 general chemistry, Microscopy, Atomic Force, 01 natural sciences, light scattering, Light scattering, Dynamic light scattering, Dispersion (optics), nanoparticle tracking analysis, Pharmacology (medical), Static light scattering, tunable resistive pulse sensing, particle size distribution, Particle Size, Pharmacology, Microscopy, Organic Chemistry, [SDV.SP]Life Sciences [q-bio]/Pharmaceutical sciences, 021001 nanoscience & nanotechnology, Particle size distribution, Dynamic Light Scattering, Fractionation, Field Flow, 0104 chemical sciences, Microscopy, Electron, [CHIM.POLY]Chemical Sciences/Polymers, [SDV.SP.PG]Life Sciences [q-bio]/Pharmaceutical sciences/Galenic pharmacology, Particle-size distribution, microscopy, Molecular Medicine, Particle, Nanoparticles, Particle size, 0210 nano-technology, Sciences agricoles, Biotechnology
Abstract

International audience; PURPOSE: Evaluation of particle size distribution (PSD) of multimodal dispersion of nanoparticles is a difficult task due to inherent limitations of size measurement methods. The present work reports the evaluation of PSD of a dispersion of poly(isobutylcyanoacrylate) nanoparticles decorated with dextran known as multimodal and developed as nanomedecine.METHODS: The nine methods used were classified as batch particle i.e. Static Light Scattering (SLS) and Dynamic Light Scattering (DLS), single particle i.e. Electron Microscopy (EM), Atomic Force Microscopy (AFM), Tunable Resistive Pulse Sensing (TRPS) and Nanoparticle Tracking Analysis (NTA) and separative particle i.e. Asymmetrical Flow Field-Flow Fractionation coupled with DLS (AsFlFFF) size measurement methods.RESULTS: The multimodal dispersion was identified using AFM, TRPS and NTA and results were consistent with those provided with the method based on a separation step prior to on-line size measurements. None of the light scattering batch methods could reveal the complexity of the PSD of the dispersion.CONCLUSIONS: Difference between PSD obtained from all size measurement methods tested suggested that study of the PSD of multimodal dispersion required to analyze samples by at least one of the single size particle measurement method or a method that uses a separation step prior PSD measurement.

Published
2016

8. Ozonation of sunflower oils: Impact of experimental conditions on the composition and the antibacterial activity of ozonized oils

Author

Frédéric Violleau, Djamila Ali Haimoud-Lekhal, Sophie Moureu, A. Calmon, Chimie Agro-Industrielle (CAI), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Ecole d'Ingénieurs de Purpan (INPT - EI Purpan), and Midi-Pyrenees Region [12050572]

Subjects
Staphylococcus aureus, Linoleic acid, chemistry.chemical_element, Mastitis, Iodine, Biochemistry, Peroxide, Ozonized sunflower oil, Ozonation conditions, chemistry.chemical_compound, Ozone, [SDV.IDA]Life Sciences [q-bio]/Food engineering, Escherichia coli, Humans, Plant Oils, Sunflower Oil, Organic chemistry, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Food science, Molecular Biology, Organic Chemistry, Streptococcus, Cell Biology, Antimicrobial, Sunflower, Anti-Bacterial Agents, Oleic acid, chemistry, Composition (visual arts), Antibacterial activity, Fatty acid composition
Abstract

International audience; Ozone can react with vegetable oils to produce ozonized oils which have antimicrobial properties and can be used in dermatology. The aim of this study was to evaluate the influence of ozonation conditions and of the initial fatty acid composition on iodine index (II), peroxide index (IP), acidity value (AV) of ozonized sunflower oils. The antibacterial activity of these products against the three bacterial strains that are more often involved in mastitis (Staphylococcus aureus,Escherichia coli and Streptococcus uberis) was also evaluated. In that purpose, two different sunflower oils have been studied: a "classical" oil (55% linoleic acid, 35% oleic acid) and a "high oleic" oil (90% oleic acid). Both were ozonized with or without water during different times (from 1 to 7 h). Results show that the addition of water has a direct impact on the increase in IP (up to 2600 meq of active oxygen/kg of oil with water and 430 without) and AV but does not influence the kinetic of the decrease in II. Minimal inhibitory concentrations were ranging from 1.25 to 40 mg/mL and the antibacterial activity of oils ozonized with water was better than the one of oils ozonized alone. These results are an open door to new applications of ozonized oils.

Published
2015

9. Impact of Cultivar and Environment on Size Characteristics of Wheat Proteins Using Asymmetrical Flow Field-Flow Fractionation and Multi-Angle Laser Light Scattering

Author

T. Aussenac, E. Lemelin, L. Salvo, V. Lein, and Frédéric Violleau

Subjects
Field flow fractionation, Chromatography, Chemistry, Sodium, Sonication, Organic Chemistry, Analytical chemistry, Wheat flour, food and beverages, chemistry.chemical_element, Fractionation, Plant protein, Molar mass distribution, Multi-Angle Laser Light Scattering, Food Science
Abstract

The use of multi-angle laser light scattering (MALLS) in conjunction with asymmetrical flow field-flow fractionation (A-FFFF) was investigated for the determination of the molecular weight distribution (MWD) of wheat proteins. The wheat flour proteins were dissolved by sonication in 0.1M sodium phosphate (pH 6.9) containing 2% SDS. The results presented make it evident that efficient separation and size characterization of monomeric (M < 105 g/mol) and polymeric protein (105 ≤ M < 108 g/mol) wheat proteins can be achieved with A-FFFF/MALLS/UV in a single run. Therefore, this method appears to be able to detect significant modifications of MWD of wheat protein, whatever the factor inducing these alterations (i.e., genetic or environmental) and whatever the nature of these alterations (i.e., monomeric-to-polymeric ratio or MWD of polymeric protein). In the present study, we have indeed demonstrated that the MWD of wheat proteins can be altered from one cultivar to another in three main ways: by cha...

Published
2005

10. Optical methyl 2-chloropropionate synthesis by decomposition of methyl 2-(chlorocarbonyloxy)propionate with hexaalkylguanidinium chloride hydrochloride

Author

Frédéric Violleau, Pierre Le Gars, Sophie Thiebaud-Roux, and Elisabeth Borredon

Subjects
inorganic chemicals, chemistry.chemical_classification, Hydrochloride, Organic Chemistry, Inorganic chemistry, Biochemistry, Medicinal chemistry, Chloride, Decomposition, Catalysis, chemistry.chemical_compound, chemistry, Drug Discovery, medicine, Propionate, Nucleophilic substitution, SN2 reaction, Racemization, medicine.drug
Abstract

The decomposition of methyl S-(−)-2-(chlorocarbonyloxy)propionate in the presence of hexaalkylguanidinium chloride hydrochloride was confirmed to correspond to a nucleophilic substitution of the second order. However, racemization occured by the contact between the catalyst and methyl R-(+)-2-chloropropionate ( I ). This phenomenon is caused by the exchange between the chloride ion from catalyst and the chlorine atom of ( I ) according to a SN2 mechanism as well.

Published
2002

11. Asymmetrical flow field-flow fractionation with multi-angle light scattering and quasi elastic light scattering for characterization of poly(ethyleneglycol-b-ɛ-caprolactone) block copolymer self-assemblies used as drug carriers for photodynamic therapy

Author

Frédéric Violleau, Anne-Françoise Mingotaud, Jérôme Ehrhart, Interactions moléculaires et réactivité chimique et photochimique (IMRCP), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Fluides, Energie, Réacteurs, Matériaux et Transferts (FERMAT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), IDeAS - Interfaces Dynamiques et Assemblages Stimulables (IDeAS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)

Subjects
Light, Multiangle light scattering, Biochemistry, Light scattering, Polyethylene Glycols, Analytical Chemistry, Lactones, Dynamic light scattering, Scattering, Radiation, Organic chemistry, [CHIM]Chemical Sciences, Photosensitizer, Static light scattering, Particle Size, chemistry.chemical_classification, Drug Carriers, Field flow fractionation, Photosensitizing Agents, Chromatography, Chemistry, Scattering, Organic Chemistry, General Medicine, Polymer, Fractionation, Field Flow, [CHIM.POLY]Chemical Sciences/Polymers, Photochemotherapy, Chemical engineering, Nanoparticles
Abstract

Poly(ethyleneoxide-b-ɛ-caprolactone) (PEO-b-PCL) self-assemblies in water were characterized by asymmetrical flow field-flow fractionation (AsFlFFF), with on-line coupling with quasi-elastic light scattering (QELS), multi-angle light scattering (MALS), refractive index and UV/Vis detection. We report here the AsFlFFF analysis of three different nanoparticular self-assembled systems of PEO-PCL polymers in aqueous media, each polymer differing by the mass of the PEO and PCL fragments. Thus, self-assembled water samples of {PEO(2000)-b-PCL(2600)}, {PEO(5000)-b-PCL(1400)} and {PEO(5000)-b-PCL(4000)} were analyzed by AsFlFFF. In most cases, the size obtained by AsFlFFF was similar to the one characterized by DLS. However, in some instances, only AsFlFFF revealed the presence of several self-assemblies with very different sizes. These nanoparticles being used for the targeted delivery of photosensitizers in photodynamic therapy, it was important to fully characterize the samples in terms of size and size distribution, molecular weight, Ip, aggregation number and also to assess whether the photosensitizer was inside the nanoparticles. AsFlFFF proved to be a very efficient technique which enabled this study without any destruction of the nanoparticles.

Published
2011

12. ChemInform Abstract: A Safe and Efficient Procedure to Prepare Alkyl and Alkoxyalkyl Chlorides and Dichlorides by Catalytic Decomposition of the Corresponding Alkyl and Alkoxyalkyl Chloroformates and Bischloroformates with Hexabutylguanidinium Chloride

Author

Sophie Thiébaud, Frédéric Violleau, Pierre Le Gars, and Elisabeth Borredon

Subjects
chemistry.chemical_classification, Carbon chain, chemistry, Yield (chemistry), medicine, Organic chemistry, General Medicine, Catalytic decomposition, Chloride, Alkyl, medicine.drug
Abstract

Small amounts of hexabutylguanidinium chloride (0.01 mol%) decomposes pure chloroformates or bischloroformates with different lengths of carbon chains by a semicontinuous process to diminish run-away risk, leading to chloride compounds with high yield and purity.

Published
2010

13. Low temperature RAFT/MADIX gel polymerisation: access to controlled ultra-high molar mass polyacrylamides

Author

Aymeric Guinaudeau, Frédéric Violleau, Arnaud Cadix, Emmanuelle Read, D. James Wilson, Mathias Destarac, Solvay (France), Ecole d'Ingénieurs de Purpan (INPT - EI Purpan), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)

Subjects
Kinetic chain length, Molar mass, Aqueous solution, Polymers and Plastics, 010405 organic chemistry, Organic Chemistry, Bioengineering, Raft, 010402 general chemistry, 01 natural sciences, Biochemistry, 0104 chemical sciences, chemistry.chemical_compound, Monomer, chemistry, Polymerization, Polymer chemistry, [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS
Abstract

We pushed back the limits of molar mass control in aqueous RAFT/MADIX polymerisation through a fast and quantitative gel polymerisation of a series of acrylamido monomers. Unprecedentedly high Mn up to 106 g mol−1 with low dispersities (Đ < 1.2) was achieved in homopolymerisation, statistical and block copolymerisation of a selection of acrylamido monomers such as AM, DMA, AMPS and NIPAM. The reasons for access to an abnormally high kinetic chain length in the presence of a RAFT/MADIX agent are discussed.

Published
2014

14. Aqueous RAFT/MADIX polymerisation of vinylphosphonic acid

Author

Mathias Destarac, Roland Geagea, Stéphane Mazières, Frédéric Violleau, Olivier Coutelier, and Issam Blidi

Subjects
Aqueous solution, Polymers and Plastics, Organic Chemistry, Bioengineering, Raft, Biochemistry, Vinylphosphonic acid, chemistry.chemical_compound, Monomer, Transfer agent, chemistry, Polymerization, Polymer chemistry, lipids (amino acids, peptides, and proteins), Xanthate, Macromolecule
Abstract

RAFT/MADIX polymerisation of vinylphosphonic acid (VPA) was controlled in water with an O-ethyl xanthate transfer agent. This represents the first example of reversible deactivation radical polymerisation of a monomer bearing an unprotected phosphonic acid function. Hence, macromolecular engineering of polyphosphonates can now be envisioned by directly polymerising VPA in water.

Published
2012

15. Drug Release by Direct Jump from Poly(ethylene-glycol-b-ε-caprolactone) Nano-Vector to Cell Membrane

Author

Anne-Françoise Mingotaud, Marie-Pierre Rols, Frédéric Violleau, Jean-Pierre Souchard, Patricia Vicendo, Christophe Mingotaud, Alix Poinso, Luc Wasungu, Jérôme Ehrhart, Laure Gibot, Ugo Till, Interactions moléculaires et réactivité chimique et photochimique (IMRCP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Institut de pharmacologie et de biologie structurale (IPBS), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Chimie Agro-Industrielle (CAI), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Fluides, Energie, Réacteurs, Matériaux et Transferts (FERMAT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), IDeAS - Interfaces Dynamiques et Assemblages Stimulables (IDeAS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques (ENSIACET), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Vicendo, Patricia, and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
Chlorophyll, Drug Evaluation, Preclinical, Pharmaceutical Science, Polymer micelles, 02 engineering and technology, 01 natural sciences, Micelle, nanoparticule, Analytical Chemistry, Polyethylene Glycols, Cell membrane, chemistry.chemical_compound, Lactones, Uptake mechanism, [CHIM.GENI]Chemical Sciences/Chemical engineering, Drug Discovery, Cellular localization, Micelles, Drug Carriers, Photosensitizing Agents, Chemistry, nanoparticle, Chimical engineering, voie de penetration, polymer micelles, pheophorbide-a, cellular penetration, uptake mechanism, 021001 nanoscience & nanotechnology, Fluorescence, medicine.anatomical_structure, Chemistry (miscellaneous), Drug delivery, Molecular Medicine, 0210 nano-technology, Phototoxicity, Caprolactone, Hydrophobic and Hydrophilic Interactions, mécanisme d'absorption, copolymère, Stereochemistry, Cell Survival, 010402 general chemistry, Article, lcsh:QD241-441, lcsh:Organic chemistry, micelle, medicine, Génie chimique, Humans, Physical and Theoretical Chemistry, Cellular penetration, copolymer, Organic Chemistry, Pheophorbide-a, Penetration (firestop), HCT116 Cells, 0104 chemical sciences, Drug Liberation, Kinetics, Biophysics, Biologie cellulaire
Abstract

Drug delivery by nanovectors involves numerous processes, one of the most important being its release from the carrier. This point still remains unclear. The current work focuses on this point using poly(ethyleneglycol-b-ε-caprolactone) micelles containing either pheophorbide-a (Pheo-a) as a fluorescent probe and a phototoxic agent or fluorescent copolymers. This study showed that the cellular uptake and the phototoxicity of loaded Pheo-a are ten times higher than those of the free drug and revealed a very low cellular penetration of the fluorescence-labeled micelles. Neither loaded nor free Pheo-a displayed the same cellular localization as the labeled micelles. These results imply that the drug entered the cells without its carrier and probably without a disruption, as suggested by their stability in cell culture medium. These data allowed us to propose that Pheo-a directly migrates from the micelle to the cell without disruption of the vector. This mechanism will be discussed.

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