References of "Jérôme, Christine"
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See detailLight induced functionalization of PCL-PEG block copolymers for the covalent immobilization of biomolecules
Pourcelle, Vincent; Freichels, Hélène ULg; Stoffelbach, François et al

in Biomacromolecules (2009), 10(4), 966-974

Functionalized poly-ε-caprolactone-block-polyethyleneglycol (PCL-PEG) amphiphilic copolymers were prepared to be constituents of nanocarriers used for the targeting of specific cells. Hence, we conceived ... [more ▼]

Functionalized poly-ε-caprolactone-block-polyethyleneglycol (PCL-PEG) amphiphilic copolymers were prepared to be constituents of nanocarriers used for the targeting of specific cells. Hence, we conceived a smooth and simple photografting methodology on these copolymers using a bifunctional molecular clip (O-succinimidyl-4-(p-azido-phenyl)butanoate). We prepared PCL-PEGs with pendent N-hydroxysuccinimide esters and studied the grafting with 3H-lysine, which radioactivity was counted by LSC. Several parameters were investigated, such as behavior of homopolymers, initial concentrations, irradiation, and incubation durations. Evidences of a “PEG directed photografting” are discussed and this selectivity could be improved by a selective solvent technique. The photografting on different PCL-PEGs revealed a dependency of the rates to the crystallinity of the copolymers. Several controls by SEC, DLS, and TEM of the treated copolymers were realized. Lastly, the coupling of α-d-mannopyranoside ligand was performed, reaching amounts of 5400 nmol/g of PCL-PEG. This derivatized PCL-PEG enters in the preparation of nanocarriers used for the targeting of antigen presenting cells. [less ▲]

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See detailDesign of smart polymer micelles for pH triggered drug delivery systems
Jérôme, Christine ULg

Conference (2009, April 02)

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See detailLayer-by-layer self-assembled chitosan coating on electrospun nanofibers
Croisier, Florence ULg; Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg et al

Poster (2009, April)

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well-known method for surface ... [more ▼]

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well-known method for surface coating, based on electrostatic interactions. It enables the controllable deposition of a variety of polyions including synthetic and natural materials, with designable layer structure, defined wall thickness and size. Electrospinning (ESP) technique allows the fabrication of polymer fibers ranging from nanometers to a few microns in diameter, depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate). Mats of nanofibers produced by ESP display a very large surface area-to-volume ratio and high porosity with very small pore size. The nanometric scale of electrospun fibers also proves a positive effect on cellular growth, as fibers mats mimic extracellular matrix structure. The association of these two techniques with the use of biocompatible and biodegradable polymers such as chitosan, gives outstanding prospects in the field of biomedical applications, especially for the preparation of wound dressings, artificial skin or tissue engineering scaffolds. In the present study, a charged copolymer, poly(methylmethacrylate-block-methacrylic acid), was added to a poly(ε-caprolactone) or poly(D,L-lactide) solution before electrospinning in order to obtain charges on fibers surface. Oppositely charged polyelectrolytes – chitosan and poly(styrene sulfonate) or hyaluronic acid – were then alternately deposited on these aliphatic polyester fiber “cores” using LBL method. The aliphatic polyester core was also removed selectively to confirm the existence of a multilayered shell, obtaining hollow fibers. [less ▲]

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See detailNew fluorinated surfactant for nanogels preparation
Alaimo, David ULg; Rieger, Jutta; Beigbeder, Alexandre et al

Conference (2009, March 19)

A series of novel fluorinated amphiphilic stabilizers of different architecture (diblock, grafted, or palm tree copolymers) were successfully prepared by reversible addition-fragmentation chain transfer ... [more ▼]

A series of novel fluorinated amphiphilic stabilizers of different architecture (diblock, grafted, or palm tree copolymers) were successfully prepared by reversible addition-fragmentation chain transfer and used as stabilizers for the dispersion polymerization of 2-hydroxyethyl methacrylate (HEMA) in fluorinated solvent, namely alpha,alpha,alpha-trifluorotoluene (TFT). The effect of the amount and the architecture of the copolymer on the size and the stabilization of the particles was studied. Whatever the experimental conditions, scanning electron microscopy showed the formation of submicronic (typically about 300 nm) spherical particles, with a narrow size distribution. The principal difference emerges from the concentration of surfactant. Indeed, at higher copolymer concentration, smaller and less aggregated particles were produced. These results were confirmed by dynamic light scattering but these measurements also revealed the presence of larger aggregates (1,5 micrometer). Furthermore, the surfactant properties of the copolymers were investigated by measuring the interfacial tension at the H2O/TFT interface, and the results were correlated to their stabilizing efficiency in the dispersion polymerization of HEMA. [less ▲]

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See detailThe influence of cobalt-coordination on cobalt-mediated radical polymerization of vinyl monomers
Debuigne, Antoine ULg; Piette, Yasmine ULg; Poli, Rinaldo et al

Poster (2009, March 19)

Nowadays, polymers are a part of everyday life. Researchers encouraged by growing need in high performance polymers develop new synthesis tools to manage the molecular architecture and thus the polymer ... [more ▼]

Nowadays, polymers are a part of everyday life. Researchers encouraged by growing need in high performance polymers develop new synthesis tools to manage the molecular architecture and thus the polymer properties. In this context, CRP (Controlled Radical Polymerization) techniques have been developed to obtain well-defined architectures and to control polymer parameters. Among these systems is Cobalt-Mediated Radical Polymerization (CMRP), which is based on the reversible deactivation of the growing radical chains with a cobalt complex, the cobalt (II) bis-acetylacetonate. The interest of this system is not only due to its ability to control the polymerization of very reactive monomers such as vinyl acetate (VAc) and N-vinylpyrrolidone (NVP), but also its peculiar mechanism which exhibits two pathways depending on the polymerization conditions; a reversible termination process and a degenerative chain transfer mechanism. Furthermore, it has been showed that the Co-C strength and thus the polymerization are strongly influenced by the use of some additives, such as water, dimethylformamide, dimethylsulfoxide and pyridine, which coordinate the cobalt free site. In this presentation we report the use of a preformed alkyl-cobalt(III) adduct as initiator for the polymerization of acrylonitrile (AN) and the use of these ligands in the CMRP system to synthesize well-defined poly(vinyl acetate)-b-poly(acrylonitrile) block copolymers. As a conclusion, cobalt-coordination appears today as a unique opportunity to adjust the Co-C bond strength and to push back the bounds of possibilities in terms of macromolecular engineering assisted by CMRP. [less ▲]

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See detailHow can cobalt complexes help synthetic polymer chemists?
Debuigne, Antoine ULg; Jérôme, Robert ULg; Jérôme, Christine ULg et al

Conference (2009, March 19)

Nowadays, progresses in medicine, biotechnology, microelectronic and many other fields are more and more sustained by the development of novel polymer materials with constantly improved properties and ... [more ▼]

Nowadays, progresses in medicine, biotechnology, microelectronic and many other fields are more and more sustained by the development of novel polymer materials with constantly improved properties and well-defined molecular parameters. In this context, we designed a controlled radical polymerization (CRP) technique based on cobalt complexes which is able to efficiently control the radical polymerization of challenging monomers such as vinyl acetate (VAc), N-vinyl pyrrolidone (NVP) and acrylonitrile (AN). This so-called Cobalt-Mediated Radical Polymerization (CMRP) also gave access to unique diblock copolymers by sequential polymerization of the above mentioned monomers. However, addition of isoprene to polymer chains preformed by CMRP did not lead to the expected poly(isoprene) containing copolymers. Instead, the quantitative coupling reaction of the polymer chains was observed, as assessed by the perfect doubling of the molar mass of the initial macromolecules. This result is very exciting because this so-called Isoprene-Assisted Radical Coupling (I-ARC) reaction is not limited to polymers with low molar masses and homopolymers, contrary to the existing radical chains coupling methods. Indeed, when applied to diblock copolymers, IARC constitutes a straightforward approach for the synthesis of telechelic symmetrical ABA triblock copolymers and is thus a very promising tool for macromolecular engineering. [less ▲]

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See detailPolyester nanoparticles presenting mannose residues : toward the development of new vaccine delivery systems combining biodegradability and targeting properties
Rieger, Jutta ULg; Freichels, Hélène ULg; Imberty, Anne et al

in Biomacromolecules (2009), 10(3), 651-657

We report the synthesis of fully biodegradable polymeric nanoparticles presenting mannose residues at their surface and their interaction with lectins. A simple and versatile method was used to reach the ... [more ▼]

We report the synthesis of fully biodegradable polymeric nanoparticles presenting mannose residues at their surface and their interaction with lectins. A simple and versatile method was used to reach the surface functionalization of poly(d,l-lactic acid) (PLA) nanoparticles by mannose moieties: It consists in using an amphiphilic mannosylated poly(ethylene oxide)-b-poly(-caprolactone) (PEO-b-PCL) diblock copolymer as a bioresorbable surface modifier in a simple nanoprecipitation-evaporation procedure. The size and zeta potential of the nanoparticles were found to depend on the molar copolymer/PLA ratio, demonstrating the influence of the copolymer on the formation of the nanoparticles. The bioavailability of the mannose residues as specific recognition sites on the nanoparticle surface could be demonstrated by a modified enzyme-linked lectin assay (ELLA) using biotin-labeled lectins which interact specifically with α-d-mannopyrannoside derivatives. Besides specific interaction by lectin−mannose complex formation, nonspecific adsorption of the proteins on the nanoparticle surface was observed. These results were fully supported by isothermal titration calorimetry experiments which suggested that the balance between specific and nonspecific interactions can be controlled by the amount of glycosylated polymer used for the preparation of the nanoparticles. Such nanoparticles are expected to be specifically recognized by mannose receptors, which are highly expressed in cells of the immune system. The targeting properties of these carrier systems combined with their potential adjuvant effects due to their size in the range of 200−300 nm make them attractive candidates as vaccine delivery systems. [less ▲]

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See detailSupercritical CO2 as an efficient medium for layered silicate organomodification: preparation of thermally stable organoclays and dispersion in polyamide 6
Naveau, Elodie ULg; Calberg, Cédric ULg; Detrembleur, Christophe ULg et al

in Polymer (2009), 50(6), 1438-1446

In this study, the preparation of organoclays via a new process using supercritical carbon dioxide is described. This method turns out to be very efficient with various surfactants, in particular nonwater ... [more ▼]

In this study, the preparation of organoclays via a new process using supercritical carbon dioxide is described. This method turns out to be very efficient with various surfactants, in particular nonwater-soluble alkylphosphonium salts. The influence of the surfactant as well as of the clay nature on the thermal stability of the organoclay is evaluated by thermogravimetric analysis. Phosphonium-based montmorillonites are up to 90 °C more stable than ammonium-based montmorillonites. Moreover, the use of hectorite adds another 40 °C of thermal stability to the phosphonium-modified clays. These organomodified clays have been melt-blended with polyamide 6 and morphology as well as fire properties of the nanocomposites are discussed, in terms of influence of the stability of organoclays. For the first time, comparison of nanocomposites based on clay organomodified by ammonium and phosphonium salts of the very same structure is reported. [less ▲]

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See detailPreparation of multilayered chitosan-based nanofibers by combination of electrospinning and layer-by-layer deposition techniques
Croisier, Florence ULg; Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg et al

Poster (2009, March)

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well known method for surface ... [more ▼]

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well known method for surface coating, based on electrostatic interactions. It enables the controllable deposition of a variety of polyions including synthetic and natural materials, with designable layer structure, defined wall thickness and size. Electrospinning (ESP) technique allows the fabrication of polymer fibers ranging from nanometers to a few microns in diameter, depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate) (3). Mats of nanofibers produced by ESP display a very large surface area-to-volume ratio and high porosity with very small pore size. The nanometric scale of electrospun fibers also proves a positive effect on cellular growth, as fibers mats mimic extracellular matrix structure. The association of these two techniques with the use of biocompatible and biodegradable polymers such as chitosan, gives outstanding prospects in the field of biomedical applications, especially for the preparation of wound dressings, artificial skin or tissue engineering scaffolds. In the present study, a charged copolymer, poly(methylmethacrylate-block-methacrylic acid), was added to a poly(ε-caprolactone) or poly(D,L-lactide) solution before electrospinning in order to obtain charges on fibers surface. Oppositely charged polyelectrolytes – chitosan and poly(styrene sulfonate) or hyaluronic acid – were then alternately deposited on these aliphatic polyester fiber “cores” using LBL method. The aliphatic polyester core was also removed selectively to confirm the existence of a multilayered shell, obtaining hollow fibers. [less ▲]

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See detailOverview of cobalt-mediated radical polymerization: roots, state of the art and future prospects
Debuigne, Antoine ULg; Poli, Rinaldo; Jérôme, Christine ULg et al

in Progress in Polymer Science (2009), 34(3), 211-239

Controlled radical polymerization (CRP) techniques offer the opportunity to properly design polymer chains and adjust their chemical and physical properties. Among these techniques, cobalt-mediated ... [more ▼]

Controlled radical polymerization (CRP) techniques offer the opportunity to properly design polymer chains and adjust their chemical and physical properties. Among these techniques, cobalt-mediated radical polymerization (CMRP) distinguished itself by the high level of control imparted to the polymerization of acrylic and vinyl ester monomers, even for high molar masses. This article summarizes for the first time the advances in understanding and synthetic scope of CMRP since its discovery. Notably, the cobalt–carbon bond formation by dual contribution of reversible termination and degenerative chain transfer is discussed, as well as the impact of additives able to coordinate the metal. The potential of computational chemistry in the field of CMRP as a rationalization and predicting tool is also presented. These mechanistic considerations and achievements in macromolecular engineering will be discussed along with challenges and future prospects in order to assess the CMRP system as a whole. [less ▲]

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See detailSynthesis of polylactide/clay nanocomposites by in situ intercalative polymerization in supercritical carbon dioxide
Urbanczyk, Laetitia ULg; Ngoundjo, Fred; Alexandre, Michaël ULg et al

in European Polymer Journal (2009), 45(3), 643-648

Polylactide (PLA)/clay nanocomposites have been prepared by in situ ring-opening polymerization in supercritical carbon dioxide. Depending on the type of organoclay used, polylactide chains can be grafted ... [more ▼]

Polylactide (PLA)/clay nanocomposites have been prepared by in situ ring-opening polymerization in supercritical carbon dioxide. Depending on the type of organoclay used, polylactide chains can be grafted onto the clay surface, leading to an exfoliated morphology. Nanocomposites with high clay contents (30–50 wt.%), called masterbatches, have also been successfully prepared and were recovered as fine powders thanks to the unique properties of the supercritical fluid. Dilution of these masterbatches into commercial l-polylactide by melt blending has led to essentially exfoliated nanocomposites containing 3 wt.% of clay. The mechanical properties of these materials have been assessed by flexion and impact tests. Significant improvements of stiffness and toughness have been observed for the PLA/clay nanocomposites compared to the pure matrix, together with improved impact resistance. [less ▲]

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See detailpH-sensitive micellar systems for controlled drug delivery: synthesis and structural characterization by small-angle neutron scattering
Joset, Arnaud ULg; Jérôme, Christine ULg; Brulet, Annie et al

Poster (2009, March)

The aim of the project is the preparation of micellar nanocarriers made of biocompatibles copolymers and their structural analysis by Small Angle Neutron Scattering (SANS). These micelles could be used in ... [more ▼]

The aim of the project is the preparation of micellar nanocarriers made of biocompatibles copolymers and their structural analysis by Small Angle Neutron Scattering (SANS). These micelles could be used in drug delivery applications to fight cancer1. The hydrophobic polycaprolactone (PCL) core is intended to incorporate the drug. The corona of hydrophilic polyethylene oxide (PEO) stabilizes the nanocarriers with respect to the plasma proteins. The pH in the neighborhood of the tumoral cells is lower than in the healthy cells. We incorporated a pH-sensitive sequence of poly(2-vinylpyridine) (P2VP). As a result, these micelles are expected to deliver their drug near the cancerous cells without affecting the healthy cells. When the pH is acidic, the P2VP is protonated and the chains are repulsive. The micellar size is then larger than in basic pH, when the P2VP is precipitated on the PCL core. We prepared PCL65-b-P2VP31 / PCL65-b-PEO114 and PCL32-b-P2VP52 / PCL36-b-PEO114 50:50 mixtures of diblocks copolymers. The resulting mixed micelles are analyzed by SANS. We developed a theoretical model with a spherical water-free PCL core. The PEO corona is described as consisting of gaussian chains with a thickness estimated as twice the chain gyration radius, Rg. We propose two alternatives for handling the P2VP zone. The P2VP molecules are either assumed to be Gaussian chains or they fill a shell of thickness L with possible water penetration.The fitting of the models to the experimental scattering cross sections leads to important structural parameters like the aggregation number, the core radius, the gyration radius and the thickness of the P2VP shell. [less ▲]

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See detailRelevance of a prereaction for the in situ NMP of styrene using the C-phenyl-N-tert-butylnitrone/2,2’-azobis(isobutyronitrile) pair
Sciannamea, Valérie; Catala, Jean-Marie; Jérôme, Robert ULg et al

in Journal of Polymer Science. Part A, Polymer Chemistry (2009), 47(4), 1085-1097

In this article, we compare two routes for carrying out in situ nitroxide-mediated polymerization of styrene using the C-phenyl-N-tert-butylnitrone (PBN)/2,2-azobis(isobutyronitrile) (AIBN) pair to ... [more ▼]

In this article, we compare two routes for carrying out in situ nitroxide-mediated polymerization of styrene using the C-phenyl-N-tert-butylnitrone (PBN)/2,2-azobis(isobutyronitrile) (AIBN) pair to identify the best one for an optimal control. One route consists in adding PBN to the radical polymerization of styrene, while the other approach deals with a prereaction between the nitrone and the free radical initiator prior to the addition of the monomer and the polymerization. The combination of ESR and kinetics studies allowed demonstrating that when the polymerization of styrene is initiated by AIBN in the presence of enough PBN at 110 °C, fast decomposition of AIBN is responsible for the accumulation of dead polymer chains at the early stages of the polymerization, in combination with controlled polystyrene chains. On the other hand, PBN acts as a terminating agent at 70 °C with the formation of a polystyrene end-capped by an alkoxyamine, which is not labile at this temperature but that can be reactivated and chain-extended by increasing the temperature. Finally, the radical polymerization of styrene is better controlled when the nitrone/initiator pair is prereacted at 85 °C for 4 h in toluene before styrene is added and polymerized at 110 °C. [less ▲]

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See detailIsoprene-assisted radical coupling of (co)polymers prepared by cobalt-mediated radical polymerization
Debuigne, Antoine ULg; Jérôme, Christine ULg; Detrembleur, Christophe ULg

in Angewandte Chemie (International ed. in English) (2009), 48(8), 1422-1424

The isoprene-assisted radical coupling (I-ARC) of polymers prepared by cobalt-mediated radical polymerization (see picture) is the first efficient radical coupling method that is not restricted to short ... [more ▼]

The isoprene-assisted radical coupling (I-ARC) of polymers prepared by cobalt-mediated radical polymerization (see picture) is the first efficient radical coupling method that is not restricted to short chains. When applied to AB diblock copolymers, I-ARC constitutes a straightforward approach to the preparation of novel symmetrical ABA triblock copolymers [less ▲]

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See detailElectrografting method for forming and regulating a strong adherent nanostructured polymer coating
Voccia, Samuel; Serwas, Harry ULg; Jérôme, Christine ULg et al

Patent (2009)

Electrografting method for forming and regulating a strongly adherent nanostructured polymer coating onto an electro-conductive surface profile characterized in that the surface profile is regulated by ... [more ▼]

Electrografting method for forming and regulating a strongly adherent nanostructured polymer coating onto an electro-conductive surface profile characterized in that the surface profile is regulated by electrodeposition of nanometre- and/or micrometre-scale nuclei onto the surface profile prior to or simultaneously to the formation of the polymer coating. [less ▲]

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See detailStainless steel grafting of hyperbranched polymer brushes with an antibacterial activity: synthesis, characterization and properties
Ignatova, Milena; Voccia, Samuel; Gabriel, Sabine et al

in Langmuir (2009), 25(2), 891-902

Two strategies were used for the preparation of hyperbranched polymer brushes with a high density of functional groups: (a) the cathodic electrografting of stainless steel by poly[2-(2-chloropropionate ... [more ▼]

Two strategies were used for the preparation of hyperbranched polymer brushes with a high density of functional groups: (a) the cathodic electrografting of stainless steel by poly[2-(2-chloropropionate)ethyl acrylate] [poly(cPEA)], which was used as a macroinitiator for the atom transfer radical polymerization of an inimer, 2-(2-bromopropionate)ethyl acrylate in the presence or absence of heptadecafluorodecyl acrylate, (b) the grafting of preformed hyperbranched poly(ethyleneimine) onto poly(N-succinimidyl acrylate) previously electrografted onto stainless steel. The hyperbranched polymer, which contained either bromides or amines, was quaternized because the accordingly formed quaternary ammonium or pyridinium groups are known for antibacterial properties. The structure, chemical composition, and morphology of the quaternized and nonquaternized hyperbranched polymer brushes were characterized by ATR-FTIR reflectance, Raman spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. The peeling test confirmed that the grafted hyperbranched polymer films adhered much more strongly to stainless steel than the nongrafted solvent-cast films. The quaternized hyperbranched polymer brushes were more effective in preventing both protein adsorption and bacterial adhesion than quaternary ammonium containing poly(cPEA) primary films, more likely because of the higher hydrophilicity and density of cationic groups. [less ▲]

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See detailSynthesis and pH-dependent micellization of diblock copolymer mixtures
Van Butsele, Kathy ULg; Sibret, Pierre ULg; Fustin, Charles-André et al

in Journal of Colloid & Interface Science (2009), 329(2), 235-243

This work focused on the preparation and the aqueous solution properties of hybrid polymeric micelles consisting of a hydrophobic poly(ε-caprolactone) (PCL) core and a mixed shell of hydrophilic poly ... [more ▼]

This work focused on the preparation and the aqueous solution properties of hybrid polymeric micelles consisting of a hydrophobic poly(ε-caprolactone) (PCL) core and a mixed shell of hydrophilic poly(ethylene oxide) (PEO) and pH-sensitive poly(2-vinylpyridine) (P2VP). The hybrid micelles were successfully prepared by the rapid addition of acidic water to a binary solution of PCL34-b-PEO114 and PCL32-b-P2VP52 diblock copolymers in N,N-dimethylformamide. These micelles were pH-responsive as result of the pH-dependent ionization of the P2VP block. The impact of pH on the self-assembly of the binary mixture of diblocks—thus on the composition, shape, size and surface properties of the micelles—was studied by a variety of experimental techniques, i.e., dynamic and static light scattering, transmission electron microscopy, Zeta potential, fluorescence spectroscopy and complement hemolytic 50 test. [less ▲]

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See detailSelf-assembly and pH-responsiveness of ABC miktoarm star terpolymers
Van Butsele, Kathy ULg; Fustin, Charles-André; Gohy, Jean-François et al

in Langmuir (2009), 25(1), 107-111

This work deals with the self-assembly in water of ABC miktoarm star terpolymers consisting of hydrophobic poly(-caprolactone), hydrophilic poly(ethylene oxide) (PEO), and pH-sensitive poly(2 ... [more ▼]

This work deals with the self-assembly in water of ABC miktoarm star terpolymers consisting of hydrophobic poly(-caprolactone), hydrophilic poly(ethylene oxide) (PEO), and pH-sensitive poly(2-vinylpyridine) (P2VP). A variety of experimental techniques were used, including dynamic light scattering, transmission electron microscopy, and zeta potential. Special attention was paid to the pH dependency of the supramolecular self-assemblies. A key observation is the capability of the miktoarm terpolymers to form micelles stable over the whole range of pH, although a transition was observed from neutral to highly positively charged nanoobjects upon decreasing pH. [less ▲]

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See detailPaclitaxel-loaded PEGylated PLGA-based nanoparticles: in vitro and in vivo evaluation
Danhier, Fabienne; Lecouturier, Nathalie; Vroman, Benoît et al

in Journal of Controlled Release (2009), 133(1), 11-17

The incorporation efficiency of PTX was higher with the nanoprecipitation technique. The release behavior of PTX exhibited a biphasic pattern characterized by an initial burst release followed by a slower ... [more ▼]

The incorporation efficiency of PTX was higher with the nanoprecipitation technique. The release behavior of PTX exhibited a biphasic pattern characterized by an initial burst release followed by a slower and continuous release. The in vitro anti-tumoral activity was assessed using the Human Cervix Carcinoma cells (HeLa) by the MTT test and was compared to the commercial formulation Taxol® and to Cremophor® EL. When exposed to 25 µg/ml of PTX, the cell viability was lower for PTX-loaded nanoparticles than for Taxol® (IC50 5.5 vs 15.5 µg/ml). Flow cytometry studies showed that the cellular uptake of PTX-loaded nanoparticles was concentration and time dependent. Exposure of HeLa cells to Taxol® and PTX-loaded nanoparticles induced the same percentage of apoptotic cells. PTX-loaded nanoparticles showed greater tumor growth inhibition effect in vivo on TLT tumor, compared with Taxol®. Therefore, PTX-loaded nanoparticles may be considered as an effective anticancer drug delivery system for cancer chemotherapy. [less ▲]

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