References of "Riva, Raphaël"
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See detailAliphatic polyphosphates: a promising family of polymers for drug delivery
Vanslambrouck, Stéphanie ULg; Clément, Benoit; Riva, Raphaël ULg et al

Poster (2015, May 18)

Thanks to their biocompatibility and biodegradability, polyphosphates are appealing polymers for biomedical applications. In contrast to polyesters, polyphosphate properties and functionality are easily ... [more ▼]

Thanks to their biocompatibility and biodegradability, polyphosphates are appealing polymers for biomedical applications. In contrast to polyesters, polyphosphate properties and functionality are easily tuned via the chemical nature of the lateral chains. In this work, a series of amphiphilic PEO-block-polyphosphate copolymers were synthesized by organo-catalyzed ring-opening polymerization of cyclic phosphates. These polymers are directly dissolved in water in the absence of any organic solvent and they self-assemble to form nanoparticles Our work aims at changing the lateral chain of polyphosphates to investigate the influence of this structural modification on (i) the size of the nanoparticles, (ii) the critical aggregation concentration, (iii) the encapsulation of an hydrophobic drug in the core of the nanoparticles and, finally, (iv) the release of the drug. [less ▲]

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See detailPoly(ethylene glycol) grafted polylactide based copolymers for the preparation of PLA-based nanocarriers and hybrid hydrogel
Riva, Raphaël ULg; Schmeits, Stéphanie; Croisier, Florence ULg et al

in Clinical Hemorheology and Microcirculation (2015), 60

In previous works, poly(D,L-lactide-co-?CL-poly(ethylene glycol) (poly(D,L-La-co-?PEG?CL) amphiphilic graft- 10 copolymers were successfully synthesized according to a copper azide-alkyne cycloaddition ... [more ▼]

In previous works, poly(D,L-lactide-co-?CL-poly(ethylene glycol) (poly(D,L-La-co-?PEG?CL) amphiphilic graft- 10 copolymers were successfully synthesized according to a copper azide-alkyne cycloaddition (CuAAC) strategy. This paper aims 11 at reporting on the behavior of this amphiphilic copolymer in water, which was not studied in the previous paper. Moreover, 12 the ability of the copolymer to stabilize a PLA nanoparticles aqueous suspension is presented. For this purpose, dynamic 13 light scattering (DLS) and transmission electron microscopy (TEM) are proposed to characterize the nanoparticles in solution. 14 Otherwise, the strategy developed for the synthesis of the amphiphilic copolymers was adapted and extended to the synthesis of 15 PLA-based degradable hydrogel, potentially applicable as drug-loaded degradable polymer implant. [less ▲]

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See detailSynthesis and tensioactive properties of PEO-b-polyphosphate copolymers
Vanslambrouck, Stéphanie ULg; Clément, Benoit; Riva, Raphaël ULg et al

in RSC Advances (2015), 5(35), 27330-37337

Poly(ethylene oxide) (PEO)-b-polyphosphate copolymers made of hydrophilic PEO and hydrophobic polyphosphates are amphiphilic copolymers prone to self-assemble in water into nanoparticles. In this work ... [more ▼]

Poly(ethylene oxide) (PEO)-b-polyphosphate copolymers made of hydrophilic PEO and hydrophobic polyphosphates are amphiphilic copolymers prone to self-assemble in water into nanoparticles. In this work, nanoparticles are obtained by the self-assembly of PEO-b-polyphosphate copolymers in water in the absence of any organic co-solvent whatever the length of the pendant alkyl chain (between 4 and 7 carbon atoms) of the polyphosphate block. Remarkably, this solvent-free process remains efficient even for the most hydrophobic polyphosphate blocks. The critical aggregation concentration (CAC) of the block copolymers was determined by pyrene probe fluorescence. Finally, the efficiency of these copolymer surfactants to decrease the air–water interface was measured by air-bubble tensiometry. [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 detailSmart cross-linked polymer micelles for drug delivery
Riva, Raphaël ULg; Vanslambrouck, Stéphanie ULg; Ergül, Zeynep ULg et al

Conference (2014, November 11)

Nowadays, polymer crosslinking is widely used in industry to improve or to impart new properties to existing polymer material. In the pharmaceutical field, polymer crosslinking is of great interest for ... [more ▼]

Nowadays, polymer crosslinking is widely used in industry to improve or to impart new properties to existing polymer material. In the pharmaceutical field, polymer crosslinking is of great interest for the elaboration of drug delivery devices, mostly hydrogels. Nevertheless, crosslinking is also very useful in nanovectorization of active principle. Indeed, each day, new drugs are synthesized and available on the market but in too many cases, the high hydrophobicity of some drugs makes them useless because of the absence of an appropriated administration method. The encapsulation of the drug into a nanocarrier, typically in the hydrophobic core of a polymer micelle, allows a significant increase of the drugs concentration in water in addition to the protection of the active principle against degradation. However, polymer micelles suffer of the main drawback to not be stable, leading to a premature release of the drug, when the concentration falls down the critical micellar concentration (CMC), which it is rapidly observed after intravenous injection. In order to get rid of the CMC, crosslinking of the micelle core is the most proposed strategy. Nevertheless, the crosslinking of the micelle core may have a non-negligible effect on the drug loading but mainly on the drug release due to the sequestration of the drug in the network. Over the last years, our lab investigated several strategies for the crosslinking of the micelle core made of amphiphilic and biocompatible block copolymers generally by UV radiation in order to fulfill the increasingly stringent requirements of biomedical applications. These strategies are very helpful to prepare injectable nanosized cross-linked particles loaded with an active particle. For some systems, the effect of the crosslinking rate on the drug loading and the drug release was evaluated using a model drug. As the crosslinking may interfere with the drug release after internalization of the carrier into the cell, a reversible crosslinking of the micelle core was proposed. Typically, the introduction of disulfide bond as inter-chain links allowed to delay the drug release by diffusion whereas into the cell, the reduction of the disulfide bridges into corresponding thiol led to the fast disassemble of the micelle and the specific release of the drug into cytoplasm. [less ▲]

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See detailAmphiphilic copolymers containing polyphosphates for drug delivery applications
Vanslambrouck, Stéphanie ULg; Clément, Benoit; Riva, Raphaël ULg et al

Poster (2014, September 19)

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See detailMicellization of PEO-b-polyphosphate for drug delivery applications
Vanslambrouck, Stéphanie ULg; Clément, Benoit; Riva, Raphaël ULg et al

Conference (2014, July 11)

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See detailStructure-morphology relationship of polyphosphate containing polymer micelles
Vanslambrouck, Stéphanie ULg; Clément, Benoit; Riva, Raphaël ULg et al

Conference (2014, June 18)

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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 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 detailDrug delivery systems based on PEO-b-polyphosphate copolymers
Vanslambrouck, Stéphanie ULg; Clément, Benoit; Riva, Raphaël ULg et al

Poster (2014, May)

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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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See detailChitosan nanoparticles for siRNA delivery: Optimizing formulation to increase stability and efficiency
Ragelle, Héloïse; Riva, Raphaël ULg; Vandermeulen, G. et al

in Journal of Controlled Release (2014), 176

This study aims at developing chitosan-based nanoparticles suitable for an intravenous administration of small interfering RNA (siRNA) able to achieve (i) high gene silencing without cytotoxicity and (ii ... [more ▼]

This study aims at developing chitosan-based nanoparticles suitable for an intravenous administration of small interfering RNA (siRNA) able to achieve (i) high gene silencing without cytotoxicity and (ii) stability in biological media including blood. Therefore, the influence of chitosan/tripolyphosphate ratio, chitosan physicochemical properties, PEGylation of chitosan as well as the addition of an endosomal disrupting agent and a negatively charged polymer was assessed. The gene silencing activity and cytotoxicity were evaluated on B16 melanoma cells expressing luciferase. We monitored the integrity and the size behavior of siRNA nanoparticles in human plasma using fluorescence fluctuation spectroscopy and single particle tracking respectively. The presence of PEGylated chitosan and poly(ethylene imine) was essential for high levels of gene silencing in vitro. Chitosan nanoparticles immediately released siRNA in plasma while the inclusion of hyaluronic acid and high amount of poly(ethylene glycol) in the formulation improved the stability of the particles. The developed formulations of PEGylated chitosan-based nanoparticles that achieve high gene silencing in vitro, low cytotoxicity and high stability in plasma could be promising for intravenous delivery of siRNA. [less ▲]

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See detailDevice-based controlled local delivery of anastrozol into peritoneal cavity: in vitro and in vivo evaluation
Krier, Fabrice ULg; Riva, Raphaël ULg; Defrère, Sylvie et al

in Journal of Drug Delivery Science and Technology [=JDDST] (2014), 24(2), 198-204

Local treatment using drug loaded implants allows decreasing seric concentrations of the active ingredient with the purpose of limiting side effects and reaching perfect observance. Nowadays, some ... [more ▼]

Local treatment using drug loaded implants allows decreasing seric concentrations of the active ingredient with the purpose of limiting side effects and reaching perfect observance. Nowadays, some diseases are already treated with implants, but generally, by subcutaneous or intra vaginal implantation. In this work, a new implant device dedicated to the intra-peritoneal cavity was developed. For this purpose, a core-membrane polymer implant was selected. We propose an original method to determine the most appropriate membrane to control the release based on the use of Franz cells. The ability of the implant to release a constant quantity of an active ingredient will be assessed by testing implants in vitro. Finally, intra peritoneal cavity and subcutaneous in vivo implantation has been achieved in order to confirm the controlled and local release of the active ingredient. [less ▲]

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See detailChitosan: a versatile platform for pharmaceutical applications
Riva, Raphaël ULg; Jérôme, Christine ULg

in Material Matters: Chemistry Driving Performance (2014), 9(3), 95-98

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See detailReversibly cross-linked polymer micelle as smart drug dellivery device
Lecomte, Philippe ULg; Riva, Raphaël ULg; Cajot, Sébastien et al

Conference (2013, November 20)

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See detailDrug delivery systems based on amphiphilic polyphosphate-copolymers
Vanslambrouck, Stéphanie ULg; Clement, Benoît ULg; Riva, Raphaël ULg et al

Poster (2013, September 18)

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromoleculesn such as nucleic acids, polyphosphates (PPhos) are of prime interest as biomaterials. In ... [more ▼]

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromoleculesn such as nucleic acids, polyphosphates (PPhos) are of prime interest as biomaterials. In contrast to poly--caprolactone and polylactides, PPhos properties and functionality are easily tuned via the nature of the pendant group of the starting cyclic monomer. For example, by varying the length of the alkyl chain the hydrophobicity of the PPhos can be adjusted. In this work, an efficient organo-catalytic system was developed to synthesize a series of amphiphilic diblock copolymers, i.e. poly(ethylene oxide)-b-polyphosphate (PEO-b-PPhos) by ring-opening polymerization of cyclic phosphates. This novel approach prevents metallic residues to polute the final product, and which is highly desirable when biomedical applications are foreseen. For drug delivery application, the micellization of these novel diblock copolymers in aqueous media was investigated, as well as, encapsulation of an hydrophobic drug. Data on, the influence of the polyphosphate nature of the polymer on drug loading will be presented. [less ▲]

Detailed reference viewed: 70 (17 ULg)