References of "Jérôme, Christine"
     in
Bookmark and Share    
Full Text
See detailOrganic compositions for repeatedly adjustable optical elements and such elements
Jérôme, Christine ULg; Alexandre, Michaël ULg; Jellali, Rachid ULg

Patent (2011)

The invention relates to an organic transparent liquid composition comprising preformed polymeric chains having some photoactive groups per chain that can reversibly couple, being capable in this way to ... [more ▼]

The invention relates to an organic transparent liquid composition comprising preformed polymeric chains having some photoactive groups per chain that can reversibly couple, being capable in this way to form a transparent solid polymer network with a shape that can be repeatedly and reversibly adjusted by at least local irradiation of the network with electromagnetic waves of different wave lengths whereby the liquid composition is cross-linked at at least one wave length L1 on the one hand and is liquid again by cleaving the cross-link nodes by irradiating the material at at least one other wavelength L2 on the other hand in order to repeatedly adjust the optical properties of said composition in its photo-cross linked state. The composition is applicable as a starting material for intraocular lenses and for other lenses and optical elements. [less ▲]

Detailed reference viewed: 44 (2 ULg)
Full Text
See detailDisulfide bridges, new prospect in drug delivery systems?
Cajot, Sébastien ULg; Danhier, F.; Schol, Daureen ULg et al

Poster (2011, September 03)

Detailed reference viewed: 24 (5 ULg)
Full Text
See detailGlucose-responsive layer-by-layer microcapsules as self-regulated insulin delivery system
Alaimo, David ULg; Detrembleur, Christophe ULg; Auzély-Velty, Rachel et al

Poster (2011, September 03)

Detailed reference viewed: 23 (3 ULg)
See detailSmart block copolymers for biomedical applications
Sibret, Pierre ULg; Schol, D; De Pauw, Marie-Claire ULg et al

Poster (2011, September 03)

Stimuli-responsive polymers are polymers that respond with rapid changes to external stimuli such as pH, temperature, light or ionic strength. Responses to the stimuli may manifest themselves as changes ... [more ▼]

Stimuli-responsive polymers are polymers that respond with rapid changes to external stimuli such as pH, temperature, light or ionic strength. Responses to the stimuli may manifest themselves as changes in solubility, shape or surface characteristics. They can also lead to the fomation of micelles or a sol-gel transition. These materials are very intersesting for different biomedical applications such as drug delivery systems, tissue engineering or sensors. In this work, we focused on two separate systems: on the one hand, micelles and, on the other hand, iron oxide nanoparticles. These nanoparticles are generally synthesized in a one-step process by alkaline coprecipitation of iron (II) and iron (III) precursors in aqueous solutions (Massart process). However, iron oxide nanoparticle suspensions produced by Massart process are not stable enough in physiological conditions to be used as is. A stabiliser coating is needed to avoid aggregation and consequent precipitation of the colloids in body fluids. For this coating, the polymer blocks chosen are: the poly(ethylene oxide) (PEO), the poly(acrylic acid) (PAA) and the poly(N-isopropyl acrylamide) (PNIPAM). The high flexibility and hydrophilicity of PEO chains make it an outstanding candidate for confering stealthiness to micelles and nanoparticles in order to avoid their rapid removal from the body by the opsonization process. The PAA is the pH-responsive block and the anchoring block. The PNIPAM is the thermoresponsive block with a thermal transition close to 37°C (99°F). Triblock copolymer was synthesized by a Reversible Addition Fragmentation Transfer Polymerization (RAFT) process combining poly(acrylic acid) PAA, poly(N-isopropylacrylamide) and poly(ethylene oxide) or poly[acrylate methoxy poly(ethylene oxide)]. This triblock copolymer was used alone to form micelles and with iron oxide to make magnetic stabilized nanoparticles. The behaviour of micelles and coated nanoparticles was investigated in different conditions by a combination of dynamic light scattering (DLS), transmission electron microscopy (TEM) and zeta potential measurements. Moreover, PAA-b-PNIPAM-b-PAMPEO nanofibers were obtained using electrospinning technique. These nanofibers present interesting prospects in the field of biomaterials and biomedical applications as they mimic the extracellular matrix of the skin. [less ▲]

Detailed reference viewed: 31 (1 ULg)
See detailStainless steel with robust anibacterial activiy based on a versatile and bio-inspired strategy
Faure, Emilie ULg; Lecomte, Philippe ULg; Vreuls, Christelle ULg et al

Conference (2011, September 01)

The synthesis of a poly(methacrylamide) bearing 3,4-dihydroxyphenylalanine inspired from the chemical composition of mussel adhesives will be presented. This homopolymer is designed to insure a multilayer ... [more ▼]

The synthesis of a poly(methacrylamide) bearing 3,4-dihydroxyphenylalanine inspired from the chemical composition of mussel adhesives will be presented. This homopolymer is designed to insure a multilayer film growth by covalent coupling during the layer-by-layer building with a homopolymer containing amino groups. The film cross-linking is initiated by adequately controlling both the redox state of the polymer and the pH of the solutions. This cross-linking is evidenced by solid-state 13C NMR with the occurrence of a typical signal of imine, traducing the Schiff base formation during film growth. The same coupling reaction is implemented for grafting an antibacterial peptide, Nisin, on a stainless steel substrate. Antibacterial activity against Bacillus subtilis is preserved even after long immersion time, as the result of the peptide covalent anchoring on the surface. All the processing steps, including the synthesis of the polymers and the peptide grafting, are performed in aqueous solutions under mild conditions. [less ▲]

Detailed reference viewed: 41 (4 ULg)
Full Text
Peer Reviewed
See detailConvenient grafting through approach for the preparation of stealth polymeric blood pool magnetic resonance imaging contrast agents
Grogna, Mathurin ULg; Cloots, Rudi ULg; Luxen, André ULg et al

in Journal of Polymer Science. Part A, Polymer Chemistry (2011), 49(17), 3700-3708

New hydrosoluble magnetic resonance imaging (MRI) macrocontrast agents are synthesized by reversible addition fragmentation chain transfer (RAFT) copolymerization of poly(ethylene oxide) methyl ether ... [more ▼]

New hydrosoluble magnetic resonance imaging (MRI) macrocontrast agents are synthesized by reversible addition fragmentation chain transfer (RAFT) copolymerization of poly(ethylene oxide) methyl ether acrylate (PEOMA) with an acrylamide bearing a ligand for gadolinium, followed by the complexation of Gd3+. This convenient and simple grafting through approach leads to macrocontrast agents with a high relaxivity at high frequency that is imparted by the restricted tumbling of the Gd3+ complex caused by its attachment to the polymer backbone. Importantly a very low protein adsorption is also evidenced by the hemolytic CH50 test. It is the result of the poly(ethylene oxide) (PEO) brush that efficiently hides the gadolinium complex and renders it stealth to the proteins of the immune system. Improved contrast and long blood circulating properties are thus expected for these macrocontrast agents. [less ▲]

Detailed reference viewed: 42 (13 ULg)
See detailPMMA/ carbon nanotube nanocomposite foams for EMI shielding application
Thomassin, Jean-Michel ULg; Vuluga, Daniela; Huynen, Isabelle et al

Conference (2011, August 30)

Detailed reference viewed: 30 (5 ULg)
Full Text
Peer Reviewed
See detailSugar-labeled and PEGylated (bio)degradable polymers intended for targeted drug delivery systems
Freichels, Hélène; Jérôme, Robert ULg; Jérôme, Christine ULg

in Carbohydrate Polymers (2011), 86(3), 1093-1106

This paper aims at giving a comprehensive view of the research effort devoted to the preparation of sugar coated long-circulating degradable polymers intended for drug delivery applications. In the recent ... [more ▼]

This paper aims at giving a comprehensive view of the research effort devoted to the preparation of sugar coated long-circulating degradable polymers intended for drug delivery applications. In the recent past, many research projects have focused on the controlled drug delivery and, therefore, on the design of drug carriers. Among them, polymeric carriers have great potential because they can be chemically modified to a large extent and so endowed with specific properties. For instance, depending on the selected polymer, either the circulation time in the bloodstream can be increased very significantly (long-circulating polymer) or the drug carrier can be completely degraded after administration. Moreover, active targeting, i.e., carriers bearing a ligand known for specific affinity for one tissue, has emerged as a method of choice in targeting the delivery of drugs. This concept is of the utmost importance because the large variety of receptors present in the body makes the selective targeting a must in order to prevent any healthy tissue from being damaged irreversibly. The purpose of this paper is to emphasize that carbohydrates are very promising pilot molecules for the next generation of drug delivery [less ▲]

Detailed reference viewed: 33 (3 ULg)
Full Text
Peer Reviewed
See detailDesign of cross-linked semicrystalline poly(ε-caprolactone)-based networks with one-way and two-way shape-memory properties through Diels–Alder
Raquez, Jean-Marie; Vanderstappen, Sophie; Meyer, Franck et al

in Chemistry : A European Journal (2011), 17(36), 10135-10143

Cross-linked poly(ε-caprolactone) (PCL)-based polyesterurethane (PUR) systems have been synthesized through Diels–Alder reactions by reactive extrusion. The Diels–Alder and retro-Diels–Alder reactions ... [more ▼]

Cross-linked poly(ε-caprolactone) (PCL)-based polyesterurethane (PUR) systems have been synthesized through Diels–Alder reactions by reactive extrusion. The Diels–Alder and retro-Diels–Alder reactions proved to be useful for enhancing the molecular motion of PCL-based systems, and therefore their crystallization ability, in the design of cross-linked semicrystalline polymers with one-way and two-way shape-memory properties. Successive reactions between alpha,omega-diol PCL (PCL2), furfuryl alcohol, and methylene diphenyl 4,4′-diisocyanate straightforwardly afforded the alpha,omega-furfuryl PCL-based PUR systems, and subsequent Diels–Alder reactions with N,N-phenylenedimaleimide afforded the thermoreversible cycloadducts. The cross-linking density could be modulated by partially replacing PCL-diol with PCL-tetraol. Interestingly, the resulting PUR systems proved to be semicrystalline cross-linked polymers, the melting temperature of which (close to 45 °C) represented the switching temperature for their shape-memory properties. Qualitative and quantitative measurements demonstrated that these PUR systems exhibited one-way and two-way shape-memory properties depending on their cross-linking density. [less ▲]

Detailed reference viewed: 40 (6 ULg)
Full Text
Peer Reviewed
See detailSynthesis of 1-vinyl-3-ethylimidazolium-based ionic liquid (co)polymers by cobalt-mediated radical polymerization
Detrembleur, Christophe ULg; Debuigne, Antoine ULg; Hurtgen, Marie ULg et al

in Macromolecules (2011), 44(16), 6397-6404

The cobalt-mediated radical polymerization (CMRP) of 1-vinyl-3-ethylimidazolium bromide (VEtImBr) is described. Polymerizations were performed at 30 °C in solution either in dimethylformamide (DMF) or in ... [more ▼]

The cobalt-mediated radical polymerization (CMRP) of 1-vinyl-3-ethylimidazolium bromide (VEtImBr) is described. Polymerizations were performed at 30 °C in solution either in dimethylformamide (DMF) or in methanol (MeOH) or in a mixture of both solvents, using a preformed alkyl–cobalt(III) adduct, CH3OC(CH3)2CH2–C(CH3)(CN)–(CH2–CHOAc)<4–Co(acac)2, as the mediating agent. Excellent control over molecular weights and dispersities (Mw/Mn 1.05–1.06) was achieved in MeOH, with a linear increase of experimental molecular weights with the monomer conversion. Substituting methanol for DMF induced much faster polymerization process, even under quite high diluted conditions: for instance, about 80% monomer conversion was reached in 30 min in DMF, compared to 10 h in MeOH. However, size exclusion chromatography (SEC) traces of PVEtImBr samples synthesized in DMF revealed a side population in the high molecular weight region, presumably due to the occurrence of irreversible coupling reactions of a small proportion of growing chains. Well-defined diblock copolymers featuring both a poly(vinyl acetate) (PVAc) block and a PVEtImBr-based poly(ionic liquid) block, PVAc-b-PVEtImBr, were next obtained by sequential CMRP of VAc and VEtImBr. To this end, a PVAc-Co(acac)2 was first prepared by CMRP and employed as a macroinitiator for the polymerization of VEtImBr either in methanol or in a mixture of DMF and MeOH (2/1: v/v) at 30 °C. Finally, cobalt-mediated radical coupling (CMRC) of the aforementioned PVAc-b-PVEtImBr diblock copolymers, using isoprene as a simple coupling agent, led to unprecedented and structurally well-defined PVAc-b-PVEtImBr-b-PVAc triblock copolymers. [less ▲]

Detailed reference viewed: 103 (17 ULg)
Full Text
Peer Reviewed
See detailThermoreversibly crosslinked poly(ε-caprolactone) as recyclable shape-memory polymer network
Defize, Thomas ULg; Riva, Raphaël ULg; Raquez, Jean-Marie et al

in Macromolecular Rapid Communications (2011), 32(16), 1264-1269

A new concept to build shape memory polymers (SMP) combining outstanding fixity and recovery ratios (both above 99% after only one training cycle) typical of chemically crosslinked SMPs with ... [more ▼]

A new concept to build shape memory polymers (SMP) combining outstanding fixity and recovery ratios (both above 99% after only one training cycle) typical of chemically crosslinked SMPs with reprocessability restricted to physically crosslinked SMPs is demonstrated by covalently bonding, through thermoreversible Diels–Alder (DA) adducts, star-shaped poly(epsilon-caprolactones) (PCL) end-functionalized by furan and maleimide moieties. A PCL network is easily prepared by melt-blending complementary end-functional star polymers in retro DA regime, then by curing at lower temperature to favour the DA cycloaddition. Such covalent network can be reprocessed when heated again at the retro DA temperature. The resulting SMP shows still excellent shape memory properties attesting for its good recyclability. [less ▲]

Detailed reference viewed: 83 (36 ULg)
Full Text
Peer Reviewed
See detailDesign and synthesis of novel DOTA(Gd3+)–polymer conjugates as potential MRI contrast agents
Grogna, Mathurin ULg; Cloots, Rudi ULg; Luxen, André ULg et al

in Journal of Materials Chemistry (2011), 21(34), 12917-12926

Conventional low molecular weight gadolinium based Magnetic Resonance Imaging (MRI) contrast agents such as Magnevist® are very useful for imaging tissues. However, at the high magnetic fields used in ... [more ▼]

Conventional low molecular weight gadolinium based Magnetic Resonance Imaging (MRI) contrast agents such as Magnevist® are very useful for imaging tissues. However, at the high magnetic fields used in modern MRI equipments, their relaxivity (contrasting efficiency) is rather poor. The grafting of the gadolinium complex onto macromolecules is a way to enhance their relaxivity provided that the rotational motion of the complex is decreased significantly. Here we report the design of novel Gd3+ based MRI contrast agents with improved relaxivity and potential long blood circulation life-time. We investigate the grafting of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid, 1,4,7-tris(1,1-dimethylethyl) ester (DO3AtBu-NH2; a precursor of Gd3+ ligand) onto well-defined functional copolymers bearing activated esters (succinimidyl esters) and poly(ethylene oxide) (PEO) chains required for stealthiness. The tert-butyl groups of grafted DO3AtBu-NH2 are then deprotected by trifluoroacetic acid followed by complexation of Gd3+. Addition of free DOTA at the end of the reaction is necessary to leave the pure and stable water soluble macrocontrast agent. Importantly it shows a relaxivity at high frequencies that is 300% higher than that of the ungrafted gadolinium complex. These novel functional copolymers are therefore promising candidates as macromolecular contrast agents for MRI applications. [less ▲]

Detailed reference viewed: 31 (10 ULg)
Full Text
Peer Reviewed
See detailEnzymatic synthesis and surface active properties of novel hemifluorinated mannose esters
Favrelle, Audrey ULg; Boyère, Cédric ULg; Laurent, Pascal ULg et al

in Carbohydrate Research (2011), 346(9), 1161-1164

The lipase-catalysed esterification of sugars with hemifluorinated acid derivatives is reported for the first time. A series of mannose modified derivatives having fluorinated chains with different length ... [more ▼]

The lipase-catalysed esterification of sugars with hemifluorinated acid derivatives is reported for the first time. A series of mannose modified derivatives having fluorinated chains with different length have been prepared accordingly in moderate yield. A preliminary evaluation of the surface active properties of these hemifluorinated mannose esters revealed their ability to reduce the surface tension of water much more efficiently than their aliphatic counterparts. [less ▲]

Detailed reference viewed: 27 (10 ULg)