References of "Debuigne, Antoine"
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See detailSmall Angle X-ray Scattering Insights into the Architecture-Dependent Emulsifying Properties of Amphiphilic Copolymers in Supercritical Carbon Dioxide
Alaimo, David ULg; Hermida Merino, Daniel; Grignard, Bruno ULg et al

in Journal of Physical Chemistry B (in press)

The supramolecular assembly of a series of copolymers combining a PEO-rich hydrophilic and fluorinated CO2-philic sequences is analysed by synchrotron small-angle xray scattering (SAXS) in supercritical ... [more ▼]

The supramolecular assembly of a series of copolymers combining a PEO-rich hydrophilic and fluorinated CO2-philic sequences is analysed by synchrotron small-angle xray scattering (SAXS) in supercritical CO2, as well as in water/CO2 emulsions. These copolymers were designed to have the same molecular weight and composition, and to differ only by their macromolecular architecture. The investigated copolymers have random, block, and palm-tree architectures. Besides, thermo-responsive copolymer is also analysed, having a hydrophilic sequence becoming water-insoluble around 41 °C, i.e. just above the critical point of CO2. At the length scale investigated by SAXS, only the random copolymer appears to self-assemble in pure CO2, in the form of a disordered microgel-like network. The random, block and thermo-responsive copolymers are all able to stabilize water/CO2 emulsions but not the copolymer with the palm-tree architecture, pointing at the importance of macromolecular architecture for the emulsifying properties. A modelling of the SAXS data shows that the block and the thermo-responsive copolymers form spherical micelle-like structures containing about 70 % water and 30 % polymer. [less ▲]

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See detailIn situ bidentate to tetradentate ligand exchange reaction in cobalt-mediated radical polymerization
Kermagoret, Anthony ULg; Jérôme, Christine ULg; Detrembleur, Christophe ULg et al

in European Polymer Journal (in press)

Organometallic-mediated radical polymerization (OMRP) has seen a significant growth in the last years notably due to the development of new metal complexes, especially cobalt derivatives. Despite of this ... [more ▼]

Organometallic-mediated radical polymerization (OMRP) has seen a significant growth in the last years notably due to the development of new metal complexes, especially cobalt derivatives. Despite of this, none of the reported complexes offers optimal control for monomers with very different reactivity, which somewhat limits the synthesis of copolymers. In order to expand the scope of cobalt-mediated radical polymerization (CMRP), we investigated an in situ ligand exchange reaction for modulating the properties of the cobalt complex at the polymer chain-end and adjusting the C-Co bond strength involved in the control process. With the aim of improving the synthesis of poly(vinyl acetate)-b-poly(n-butyl acrylate) copolymers, bidentate acetylacetonate ligands, which impart high level of control to the polymerization of vinyl acetate (VAc), were replaced in situ at the PVAc-cobalt chain-end by tetradentate Salen type ligands that are more suited to acrylates. [less ▲]

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See detailDirect route to well-defined poly(ionic liquid)s by controlled radical polymerization in water
Cordella, Daniela ULg; Kermagoret, Anthony ULg; Debuigne, Antoine ULg et al

in ACS Macro Letters (2014), 3

The precision synthesis of poly(ionic liquid)s (PILs) in water is achieved for the first time by the cobalt-mediated radical polymerization (CMRP) of N-vinyl-3-alkylimidazolium-type monomers following two ... [more ▼]

The precision synthesis of poly(ionic liquid)s (PILs) in water is achieved for the first time by the cobalt-mediated radical polymerization (CMRP) of N-vinyl-3-alkylimidazolium-type monomers following two distinct protocols. The first involves the CMRP of various 1-vinyl-3-alkylimidazolium bromides conducted in water in the presence of an alkyl–cobalt(III) complex acting as a monocomponent initiator and mediating agent. Excellent control over molar mass and dispersity is achieved at 30 °C. Polymerizations are complete in a few hours, and PIL chain-end fidelity is demonstrated up to high monomer conversions. The second route uses the commercially available bis(acetylacetonato)cobalt(II) (Co(acac)2) in conjunction with a simple hydroperoxide initiator (tert-butyl hydroperoxide) at 30, 40, and 50 °C in water, facilitating the scaling-up of the technology. Both routes prove robust and straightforward, opening new perspectives onto the tailored synthesis of PILs under mild experimental conditions in water. [less ▲]

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See detailPoly( N-vinylcaprolactam): A thermoresponsive macromolecule with promising future in biomedical field
Liu, Ji; Debuigne, Antoine ULg; Detrembleur, Christophe ULg et al

in Advanced Healthcare Materials (2014), 3(12), 1941-1968

Poly( N -vinylcaprolactam) (PNVCL) is a thermoresponsive and biocompatible polymer that raises an increasing interest in the biomedical area, especially in drug delivery systems (DDS) that include ... [more ▼]

Poly( N -vinylcaprolactam) (PNVCL) is a thermoresponsive and biocompatible polymer that raises an increasing interest in the biomedical area, especially in drug delivery systems (DDS) that include micelles, hydrogels, and hybrid particles. The thermoresponsiveness of PNVCL, used alone or in combination with other stimuli- responsive polymers or particles (pH, magnetic fi eld, or chemicals), is often key in the loading and/or release process in these DDS. The renewed focus on this polymer, which is known for decades, is to a large extent due to recent progress in synthetic strategies. Especially, the advent of efficient controlled radical polymerization (CRP) methods for NVCL monomer gives now access to unprecedented well-defi ned NVCL-based copolymers with unique properties. This Review article addresses up-to-date synthetic aspects, biological features, and biomedical applications of the latest NVCL-containing systems. [less ▲]

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See detailInput of supercritical carbon dioxide to polymer synthesis: an overview
Boyère, Cédric; Jérôme, Christine ULg; Debuigne, Antoine ULg

in European Polymer Journal (2014), 61

The ongoing search for environmentally friendlier alternative to the organic solvents used in chemical processes has led to the development of technologies based on supercritical carbon dioxide (scCO2 ... [more ▼]

The ongoing search for environmentally friendlier alternative to the organic solvents used in chemical processes has led to the development of technologies based on supercritical carbon dioxide (scCO2), which is non-flammable, non-toxic and relatively inert fluid. Polymer chemistry does not escape this trend and last achievements in the field of polymer synthesis in scCO2 are reviewed here. Without claiming to be exhaustive, we go through and discuss the benefits of the main polymerization processes in scCO2 including homogeneous, precipitation, dispersion, suspension and emulsion systems. A particular attention is drawn to water/carbon dioxide emulsion polymerization and to the suited surface active agents. This review also underlines that heterogeneous polymerization based on CO2 is more than a strategy for reducing the ecological footprint of the polymer production but it allows structuring the polymer materials into particles or highly interconnected macroporous networks. [less ▲]

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See detailDouble thermoresponsive di- and triblock copolymers based on N-vinylcaprolactam and N-vinylpyrrolidone: synthesis and comparative study of solution behaviour
Kermagoret, Anthony ULg; Mathieu, Kevin ULg; Thomassin, Jean-Michel ULg et al

in Polymer Chemistry (2014), 5(22), 6534-6544

Poly(N-vinylcaprolactam) (PNVCL) and poly(N-vinylpyrrolidone) (PNVP) are water soluble polymers of interest especially in the biomedical field. Moreover, PNVCL is characterized by a lower critical ... [more ▼]

Poly(N-vinylcaprolactam) (PNVCL) and poly(N-vinylpyrrolidone) (PNVP) are water soluble polymers of interest especially in the biomedical field. Moreover, PNVCL is characterized by a lower critical solution temperature close to 36 °C in water, which makes it useful for the design of thermoresponsive systems. In this context, we used the cobalt-mediated radical polymerization (CMRP) and reaction coupling (CMRC) for synthesizing a series of well-defined NVCL and NVP-based copolymers, including statistical copolymers as well as double thermoresponsive diblocks and triblocks. Dynamic light scattering and turbidimetry analyses highlighted the crucial impact of the copolymer composition and architecture on the cloud point temperature (TCP) of each segment and also their influence on the multistep assembly behaviour of block copolymers. Addition of NaCl enabled us to adjust the inter-TCP range of the di- and triblock in which selective precipitation of one block and self-assembly of the copolymer were favoured. Overall, data presented here provide a basis for the synthesis of a broad range of NVCL/NVP based copolymer architectures with a tunable thermal response in water. [less ▲]

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See detailTemplating calcium carbonate drug delivery carriers based on polyphosphoester copolymers
Ergül, Zeynep ULg; Debuigne, Antoine ULg; Calvignac, Brice et al

Poster (2014, October)

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See detailThermo-responsive gold/poly(vinyl alcohol)-b-poly(N-vinylcaprolactam) core–corona nanoparticles as a drug delivery system
Liu, Ji ULg; Detrembleur, Christophe ULg; Hurtgen, Marie et al

in Polymer Chemistry (2014), 5(18), 5289-5299

Core–corona gold/poly(vinyl alcohol)-b-poly(N-vinylcaprolactam) nanoparticles (gold@PVOH-b-PNVCL NPs) were fabricated via an in situ method, where a gold salt was reduced within the macromolecular aqueous ... [more ▼]

Core–corona gold/poly(vinyl alcohol)-b-poly(N-vinylcaprolactam) nanoparticles (gold@PVOH-b-PNVCL NPs) were fabricated via an in situ method, where a gold salt was reduced within the macromolecular aqueous solution. Arrangement of macromolecular chains on the surface of gold cores was studied by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy and infrared spectroscopy. The responsiveness to temperature and the preserved colloidal stability of the gold@PVOH-b-PNVCL NPs above the lower critical solution temperature (LCST) were confirmed by dynamic light scattering and turbidity measurements. The drug loading capacity (DLC of ca. 1.3–2.8 wt%) of the gold@PVOH-b-PNVCL NPs as a drug delivery system (DDS) was tested with Nadolol®, a hydrophilic drug, and the release behaviours were studied at several temperatures. PVOH-b-PNVCL copolymers with an LCST of a few degrees above the biological temperature (37 °C), for example, PVOH180-b-PNVCL110 (LCST of 41 °C), are preferential, due to the slower release at 37 °C, but a faster release at temperatures that are a few degrees higher. The cytocompatibility of the gold@PVOH-b-PNVCL NPs against mouse fibroblastic L929 cells was evaluated via the MTS assay. Cellular uptake within MEL-5 human melanoma cells was studied by confocal laser scanning microscopy, fluorescence-activated cell sorting and TEM techniques and it showed that gold@PVOH-b-PNVCL NPs preferably accumulated within the cellular cytoplasm, with an incubation concentration and period-dependent uptake process. All these results corroborated a general utility of these thermo-responsive gold@PVOH-b-PNVCL NPs for drug delivery and controlled drug release. [less ▲]

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See detailSynthesis of well-defined ethylene-based copolymers: on track using organometallic-mediated radical polymerization
Debuigne, Antoine ULg; Kermagoret, Anthony ULg; Jérôme, Christine ULg et al

Conference (2014, September 19)

Organometallic-Mediated Radical Polymerization (OMRP)1 has received renewed interest in recent years since proving its efficiency for non-activated monomers like vinylacetate (VAc), N-vinylamides, etc ... [more ▼]

Organometallic-Mediated Radical Polymerization (OMRP)1 has received renewed interest in recent years since proving its efficiency for non-activated monomers like vinylacetate (VAc), N-vinylamides, etc. Nevertheless, important mechanistic questions and challenges remained. A major goal in the field of controlled radical polymerization today consists in the design of well-defined ethylene containing (co)polymers. A recent mechanistic study on the impact of head-to-head addition on the course of the VAc polymerization by OMRP provided a strong incentive to evaluate the copolymerization of VAc with ethylene by this technique. Indeed, the latter revealed that dormant chains resulting from inverted head-to-head additions in the VAc polymerization, which mimics a terminal ethylene-cobalt moiety, reactivates at a similar rate compared to the ones resulting from the regular head-to-tail addition. As a result, well-defined statistical and block-like ethylene-based copolymers were prepared. These achievements represent an important step towards a versatile synthetic platform for polyolefine-based materials. [less ▲]

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See detailSynthesis of degradable polyphosphoester copolymers for templating calcium carbonate drug delivery carriers
Ergül, Zeynep ULg; Debuigne, Antoine ULg; Calvignac, Brice et al

Conference (2014, July 09)

Degradable acid bearing polyphosphoester (PPE) copolymers were prepared by combination of organocatalyzed ring opening polymerization and click chemistry. Their solution behavior and ability to complex ... [more ▼]

Degradable acid bearing polyphosphoester (PPE) copolymers were prepared by combination of organocatalyzed ring opening polymerization and click chemistry. Their solution behavior and ability to complex calcium ions were studied as well as their capacity to template CaCO3 particles dedicated to drug delivery. [less ▲]

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See detailTemplating calcium carbonate drug delivery carriers based on polyphosphoester copolymers
Ergül, Zeynep ULg; Debuigne, Antoine ULg; Caalvignac, Brice et al

Poster (2014, May 27)

The design of drug delivery systems (DDS) often requires biodegradable and biocompatible materials that allow safe retention and controlled release of the drug. In this respect, CaCO3 particles are ... [more ▼]

The design of drug delivery systems (DDS) often requires biodegradable and biocompatible materials that allow safe retention and controlled release of the drug. In this respect, CaCO3 particles are appropriate drug carriers that have excellent properties such as low density, high specific surface areas and porosity for drugs and proteins encapsulation. Here, hyaluronic acid usually used for templating CaCO3 particles was substituted by a degradable synthetic copolymer based on PPE. The latter is a promising candidate due to its biocompatibility, biodegradability and the low toxicity of its degradation products such as phosphates. We also introduced acid functions on the PPE segment in order to enhance its calcium affinity and ability to tune the morphology of the CaCO3 particles. The butynyl phospholane (BYP) polymerization was initiated from poly(ethylene oxide) PEO-OH by organocatalyzed ring opening polymerization (ROP) [2] followed by UV catalyzed thiol-yne addition of 3-mercaptopropionoic acid onto the alkyne functions. CaCO3 particles were then generated in the presence of the copolymer following a procedure inspired from . Well-defined PPE copolymers bearing pendant alkynyl groups, i.e. PEO-b-PBYP (Ð <1.1), were obtained by organocatalyzed ROP of BYP initiated at 0°C from PEO-OH (Scheme 1). The copolymer was then reacted under UV with 3-mercaptopropionoic acid in order to introduce carboxylic acid functions along the PPE backbone by thiol-yne reaction. NMR analyses confirmed that full functionalization was reached after 2h. The high density of acid moieties in PEO-b-PBYP(COO-)2 is supposed to facilitate the Ca2+ complexation. The solution behavior and self-assembly of PEO-b-PBYP(COO-)2 in water was investigated by DLS with and without Ca+2 at different pH. Finally, stoichiometric amounts of CaCl2 and Na2CO3 were mixed in water containing the PEO-b-PBYP(COO-)2 which strongly influences the size of the CaCO3 particles (~1.5 µm). The acid-bearing PPE-based copolymers were successfully prepared and used as templating agents for the synthesis of CaCO3 particles. [less ▲]

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See detailSynthesis of a glucosamine labeled amphiphilic polymer for drug delivery application
Riva, Raphaël ULg; Boyère, Cédric; Debuigne, Antoine ULg et al

Poster (2014, May 27)

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See detailSynthesis of degradable polyphosphoester copolymers for templating calcium carbonate drug delivery carriers
Ergül, Zeynep ULg; Debuigne, Antoine ULg; Calvignac, Brice et al

Poster (2014, May 20)

The design of drug delivery systems (DDS) often requires biodegradable and biocompatible materials that allow safe retention and controlled release of the drug. In this respect, CaCO3 particles are ... [more ▼]

The design of drug delivery systems (DDS) often requires biodegradable and biocompatible materials that allow safe retention and controlled release of the drug. In this respect, CaCO3 particles are appropriate drug carriers that have excellent properties such as low density, high specific surface areas and porosity for drugs and proteins encapsulation. Here, hyaluronic acid usually used for templating CaCO3 particles was substituted by a degradable synthetic copolymer based on PPE. The latter is a promising candidate due to its biocompatibility, biodegradability and the low toxicity of its degradation products such as phosphates. We also introduced acid functions on the PPE segment in order to enhance its calcium affinity and ability to tune the morphology of the CaCO3 particles. The butynyl phospholane (BYP) polymerization was initiated from poly(ethylene oxide) PEO-OH by organocatalyzed ring opening polymerization (ROP) [2] followed by UV catalyzed thiol-yne addition of 3-mercaptopropionoic acid onto the alkyne functions. CaCO3 particles were then generated in the presence of the copolymer following a procedure inspired from . Well-defined PPE copolymers bearing pendant alkynyl groups, i.e. PEO-b-PBYP (Ð <1.1), were obtained by organocatalyzed ROP of BYP initiated at 0°C from PEO-OH (Scheme 1). The copolymer was then reacted under UV with 3-mercaptopropionoic acid in order to introduce carboxylic acid functions along the PPE backbone by thiol-yne reaction. NMR analyses confirmed that full functionalization was reached after 2h. The high density of acid moieties in PEO-b-PBYP(COO-)2 is supposed to facilitate the Ca2+ complexation. The solution behavior and self-assembly of PEO-b-PBYP(COO-)2 in water was investigated by DLS with and without Ca+2 at different pH. Finally, stoichiometric amounts of CaCl2 and Na2CO3 were mixed in water containing the PEO-b-PBYP(COO-)2 which strongly influences the size of the CaCO3 particles (~1.5 µm). The acid-bearing PPE-based copolymers were successfully prepared and used as templating agents for the synthesis of CaCO3 particles. [less ▲]

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See detailMetal-free synthesis of a glucosamine labeled amphiphilic polymer for drug delivery applications
Riva, Raphaël ULg; Boyère, Cécric; Debuigne, Antoine ULg et al

Poster (2014, May 19)

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See detail(Co)Polymerization of vinyl levulinate by cobalt-mediated radical polymerization and functionalization by ketoxime click chemistry
Allaoua, Imène; Eleuterio, Beatriz; Obadia, Mona M. et al

in Polymer Chemistry (2014), 5(8), 2973-2979

Vinyl levulinate is synthesized from levulinic acid by palladium-catalyzed vinyl exchange and is characterized by NMR and ESI-HRMS techniques. Homopolymerization of vinyl levulinate and random ... [more ▼]

Vinyl levulinate is synthesized from levulinic acid by palladium-catalyzed vinyl exchange and is characterized by NMR and ESI-HRMS techniques. Homopolymerization of vinyl levulinate and random copolymerization with vinyl acetate by cobalt-mediated radical polymerization affords well-defined ketone functionalized poly(vinyl ester)s. The impact of temperature, solvent and theoretical degree of polymerization on monomer conversion and control of the polymerization is studied by 1H NMR and size exclusion chromatography techniques. The ketoxime conjugation of O-benzylhydroxylamine with the pendant ketone functionality of poly(vinyl levulinate-co-vinyl acetate) is demonstrated. [less ▲]

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See detailElaboration of drug nanocarriers based on a glucosamine labeled amphiphilic polymer
Boyère, Cédric; Duhem, N; Debuigne, Antoine ULg et al

in Polymer Chemistry (2014), 5(8), 3030-3037

A new functional polymer micelle with high loading efficiency of a poorly soluble drug was made of biocompatible and/or biosourced compounds, i.e. cholesterol-poly(ethylene glycol)-glucosamine (Chol-PEG ... [more ▼]

A new functional polymer micelle with high loading efficiency of a poorly soluble drug was made of biocompatible and/or biosourced compounds, i.e. cholesterol-poly(ethylene glycol)-glucosamine (Chol-PEG-GlcNH2). A synthesis strategy combining enzymatic and metal-free click chemistry was developed in order to meet the increasingly stringent requirements of biomedical applications. After the self-assembly of the Chol-PEG-GlcNH2 amphiphilic polymer in water, the presence of glucosamine at the micelle surface confers an active targeting moiety to the nanocarriers whereas protonation of the peripheral primary amine delay their aggregation. The complete characterization of this novel functional amphiphilic bioconjugate is presented as well as its aqueous solution behaviour and encapsulation efficiency using ketoconazole as a model hydrophobic drug. [less ▲]

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