6 results on '"Coulembier, Olivier"'
Search Results
2. RGD-tagging of star-shaped PLA-PEG micellar nanoassemblies enhances doxorubicin efficacy against osteosarcoma.
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Oliva, Roberto, Torcasio, Serena Maria, Coulembier, Olivier, Piperno, Anna, Mazzaglia, Antonino, Scalese, Silvia, Rossi, Arianna, Bassi, Giada, Panseri, Silvia, Montesi, Monica, and Scala, Angela
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DOXORUBICIN , *OSTEOSARCOMA , *STAR-branched polymers , *PEPTIDES , *DIMERIZATION , *BLOCK copolymers - Abstract
[Display omitted] • RGD-NanoStar micellar nanoassemblies loaded with Doxorubicin against osteosarcoma. • Impact of RGD on nanoparticles surface for osteosarcoma chemotherapy. • Dox released from RGD-NanoStar reach the nucleus unlike untargeted NanoStar. • Preserving Doxorubicin from degradation occurring under physiological conditions. • Sustained and prolonged Dox release from RGD-NanoStar@Dox. We developed cyclic RGD-tagged polymeric micellar nanoassemblies for sustained delivery of Doxorubicin (Dox) endowed with significant cytotoxic effect against MG63, SAOS-2, and U2-OS osteosarcoma cells without compromising the viability of healthy osteoblasts (hFOBs). Targeted polymeric micellar nanoassemblies (RGD-NanoStar@Dox) enabled Dox to reach the nucleus of MG63, SAOS-2, and U2-OS cells causing the same cytotoxic effect as free Dox, unlike untargeted micellar nanoassemblies (NanoStar@Dox) which failed to reach the nucleus and resulted ineffective, demonstrating the crucial role of cyclic RGD peptide in driving cellular uptake and accumulation mechanisms in osteosarcoma cells. Micellar nanoassemblies were obtained by nanoformulation of three-armed star PLA-PEG copolymers properly synthetized with and without decoration with the cyclic-RGDyK peptide (Arg-Gly-Asp-D-Tyr-Lys). The optimal RGD-NanoStar@Dox nanoformulation obtained by nanoprecipitation method (8 % drug loading; 35 % encapsulation efficiency) provided a prolonged and sustained drug release with a rate significantly lower than the free drug under the same experimental conditions. Moreover, the nanosystem preserved Dox from the natural degradation occurring under physiological conditions (i.e., dimerization and consequent precipitation) serving as a slow-release "drug reservoir" ensuring an extended biological activity over the time. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Synthesis and characterization of original 2-(dimethylamino)ethyl methacrylate/poly(ethyleneglycol) star-copolymers
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Shim, Yong-Ho, Bougard, François, Coulembier, Olivier, Lazzaroni, Roberto, and Dubois, Philippe
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POLYETHYLENE glycol , *BLOCK copolymers , *METHYL methacrylate , *GENE transfection , *POLYELECTROLYTES , *BUFFER solutions , *LIGHT scattering - Abstract
Abstract: Novel synthetic transfection vectors with linear triblock and star-shaped diblock copolymer architectures have been synthesized by atom transfer radical polymerization (ATRP). Based on 2-(dimethylamino)ethyl methacrylate (DMAEMA) and copolymerization with poly(ethyleneglycol) α-methoxy, ω-methacrylate (MAPEG), the synthesis was realized using CuBr ligated with 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA) as catalytic complex and either ethyl 2-bromoisobutyrate (EBiB) or bis(α-bromoisobutyryl) N-methyl diethanolamine (DEA) or tris(α-bromoisobutyryl) triethanolamine (TEA) as (multifunctional)initiator. The polymers were characterized by GPC and NMR. The solution properties of these homopolymers and palm-tree-like copolymers were investigated by viscometry either in pure water or in buffered aqueous solutions. Interestingly, all the synthesized polymers show polyelectrolyte effect in Millipore water (25°C) and in Hepes (20mM) buffer solution (pH 7.4, NaCl 155mM, 25°C). Fitting of these viscometric data according to either Fuoss or Fedors equation allows for calculating the intrinsic viscosity of the polymers. These results are compared with dynamic light scattering (DLS) experiments to determine absolute masses. Finally, DEA based palm-tree-like copolymer is investigated to AFM measurement and micelles were observed at pH 8. [Copyright &y& Elsevier]
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- 2008
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4. Assessment of end-group functionality in atom transfer radical polymerization of N-isopropylacrylamide.
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D’hooge, Dagmar R., Vachaudez, Magali, Stadler, Florian J., Reyniers, Marie-Françoise, Coulembier, Olivier, Bailly, Christian, Dubois, Philippe, and Marin, Guy B.
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ACRYLAMIDE , *POLYMERIZATION , *ATOM transfer reactions , *FUNCTIONAL groups , *BLOCK copolymers , *DIFFUSION - Abstract
Highlights: [•] Assessment of end-group functionality in ATRP of NiPAm. [•] Synthesis of well-defined “smart” amphiphilic block copolymers. [•] Relevance of side reactions and diffusional limitations in ATRP of NiPAm. [ABSTRACT FROM AUTHOR]
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- 2013
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- View/download PDF
5. Amphiphilic semiconducting copolymer as compatibility layer for printing polyelectrolyte-gated OFETs
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Sinno, Hiam, Nguyen, Ha Tran, Hägerström, Anders, Fahlman, Mats, Lindell, Linda, Coulembier, Olivier, Dubois, Philippe, Crispin, Xavier, Engquist, Isak, and Berggren, Magnus
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AMPHIPHILES , *COPOLYMERS , *POLYELECTROLYTES , *ORGANIC field-effect transistors , *INK-jet printing , *ORGANIC semiconductors , *INTERFACES (Physical sciences) - Abstract
Abstract: We report a method for inkjet-printing an organic semiconductor layer on top of the electrolyte insulator layer in polyelectrolyte-gated OFETs by using a surface modification treatment to overcome the underlying wettability problem at this interface. The method includes depositing an amphiphilic diblock copolymer (P3HT-b-PDMAEMA). This material is designed to have one set of blocks that mimics the hydrophobic properties of the semiconductor (poly(3-hexylthiophene) or P3HT), while the other set of blocks include polar components that improve adhesion to the polyelectrolyte insulator. Contact angle measurements, atomic force microscopy, and X-ray photoelectron spectroscopy confirm formation of the desired surface modification film. Successful inkjet printing of a smooth semiconductor layer allows us to manufacture complete transistor structures that exhibit low-voltage operation in the range of 1V. [Copyright &y& Elsevier]
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- 2013
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6. Controlled synthesis of amphiphilic block copolymers based on polyester and poly(amino methacrylate): Comprehensive study of reaction mechanisms
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Mespouille, Laetitia, Vachaudez, Magali, Suriano, Fabian, Gerbaux, Pascal, Van Camp, Wim, Coulembier, Olivier, Degée, Philippe, Flammang, Robert, Du Prez, Filip, and Dubois, Philippe
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POLYMERIZATION , *BLOCK copolymers , *CHEMICAL reactions , *SPECTRUM analysis - Abstract
Abstract: The synthesis of amphiphilic and adaptative block copolymers has been envisioned following a commutative two-step strategy involving atom transfer radical polymerization (ATRP) and the Huisgen-1,3-dipolar cycloaddition techniques. The reliability of this strategy is based on the use of an azido-containing ATRP initiator, the 2-(2-azidoethoxy)ethylbromoisobutyrate (N3E i BBr), able to be “clicked” to an alkyne-terminated derivative and to promote the ATRP polymerization from the active site. In the context of this work, an alkyne-terminated poly(ε-caprolactone) produced by ring-opening polymerization (ROP) of CL was employed as hydrophobic “clickable” segment. The N3E i BBr initiator was obtained by nucleophilic substitution of the chloride atom from 2-(2-chloroethoxy)ethanol by an azide function and followed by the esterification of the hydroxy function by bromoisobutyryl bromide. This initiator was employed in polymerization of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA) monomer by ATRP in THF at 60°C using CuBr complexed by 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA) as catalytic complex. Low initiation efficiencies were obtained and they were ascribed to intramolecular cyclization during the polymerization as evidenced by ESI-MS and 2D NMR spectroscopy. The “Click” coupling reaction was performed in THF at r.t. and was found to be efficient when using CuBr complexed by 2,2′-bipyridine ligand. To circumvent the low initiation efficiency, the N3E i BBr could be “clicked” in a first step to PCL precursors before initiating the polymerization of DMAEMA monomer by ATRP. In this context, various catalytic complexes in different composition ratio were employed to optimize the “click” coupling step. Moreover, this strategy was found to be suitable to produce well-defined PCL-b-PDMAEMA block copolymers, characterized by narrow polydispersity indices. Since ATRP and the Huisgen-1,3-dipolar cycloaddition both require the use of a copper(I)-based catalyst, the two first strategies were merged in a “one-pot” process in order to obtain in one step a well-defined block copolymer characterized by a narrow polydispersity index and predictable composition and block lengths. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
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