Entity

Time filter

Source Type

Châtenay-Malabry, France

Nicolas J.,Laboratoire Of Physico Chimie | Brusseau S.,CNRS Chemistry Laboratory | Charleux B.,CNRS Chemistry Laboratory | Charleux B.,University Claude Bernard Lyon 1
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2010

Nitroxide-mediated controlled/living free-radical polymerization of methyl methacrylate initiated by the SG1-based alkoxyamine BlocBuilder was successfully performed In bulk at 80-99 °C with the help of a very small amount of acrylonitrile (AN, 2.2-8.8 mol %) as a comonomer. Well-defined PMMA-rich P(MMA-co-AN) copolymers were prepared with the numberaverage molar mass, M n, in the 6.1-32 kg mor-1 range and polydispersity indexes as low as 1.24. Incorporation of AN in the copolymers was demonstrated by 1H and 13C NMR spectroscopy, and its effect on the chain thermal properties was evaluated by DSC and TGA analyses. Investigation of chain-end functionalization by an alkoxyamine group was performed by means of 31P NMR spectroscopy and chain extensions from a P(MMA-co-AN)-SG1 macroinitiator. It demonstrated the very high proportion of SG 1-terminated polymer chains, which opened the door to block copolymer synthesis with a high quality of control. © 2009 Wiley Periodicals,. Source


Brambilla D.,Laboratoire Of Physico Chimie | Verpillot R.,Laboratoire Of Physico Chimie | Taverna M.,Laboratoire Of Physico Chimie | Le Droumaguet B.,Laboratoire Of Physico Chimie | And 8 more authors.
Analytical Chemistry | Year: 2010

A novel application of capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) was proposed to efficiently detect and monitor the interaction between polymeric nanoparticles and the β-Amyloid peptide (Aβ1-42), a biomarker for Alzheimer's Disease (AD), at concentrations close to physiological conditions. The CE-LIF method allowed the interaction between PEGylated poly(alkyl cyanoacrylate) nanoparticles (NPs) and the soluble Aβ1-42 peptide monomers to be highlighted. These results were confirmed by surface plasmon resonance (SPR) and confocal laser scanning microscopy (CLSM). Whereas SPR showed an interaction between the NPs and the Aβ1-42 peptide, CLSM allowed the formation of large aggregates/assemblies at high NP and peptide concentrations to be visualized. All these results suggested that these nanoparticles could bind the Aβ1-42 peptide and influence its aggregation kinetics. Interestingly, the non-PEGylated poly(alkyl cyanoacrylate) NPs did not alter the aggregation kinetics of the Aβ1-42 peptide, thus emphasizing the high level of discrimination of the CE-LIF method with respect to NPs. © 2010 American Chemical Society. Source


Nicolas J.,Laboratoire Of Physico Chimie | Brambilla D.,Laboratoire Of Physico Chimie | Carion O.,CNRS Physics and Materials Study Laboratory | Pons T.,CNRS Physics and Materials Study Laboratory | And 6 more authors.
Soft Matter | Year: 2011

Visible- and near-infrared-emitting quantum-dots (QDs) were readily encapsulated with high yields into PEGylated, poly(alkyl cyanoacrylate) nanoparticles (NPs) by self-assembly in aqueous solution. The resulting QD-loaded NPs were efficiently purified and characterized by transmission electron microscopy, dynamic light scattering and ζ-potential measurements as well as by stability studies and cell viability assays. Concomitant encapsulation of different kinds of QDs led to barcode NPs. They were then used for human brain endothelial cell imaging allowing their uptake to be monitored. Finally, the in vivo fate of near-infrared fluorescent NPs was visualized noninvasively by fluorescence optical imaging. © The Royal Society of Chemistry 2011. Source


Chenal M.,Laboratoire Of Physico Chimie | Mura S.,Laboratoire Of Physico Chimie | Marchal C.,Aix - Marseille University | Gigmes D.,Aix - Marseille University | And 4 more authors.
Macromolecules | Year: 2010

The nitroxide-mediated copolymerization of poly(ethylene glycol) methyl ether methacrylate (MePEGMA) with a small amount of acrylonitrile using an SG1-based alkoxyamine initiator was shown to be a very simple and efficient technique to synthesize graft copolymers with poly(ethylene glycol) side chains. The copolymerizations were carried out in ethanol/water solutions as environmentally friendly media. Following our observation that the rate increased with the proportion of water, a polymerization temperature as low as 71 °C could be used for a water content of 75%, which conferred great flexibility to the process. The so-formed copolymers were living, with high crossover efficiency toward block copolymers. Importantly, following a cytotoxicity study over three different cell lines that represent important mammalian cell types, these polymers were shown to be noncytotoxic even at very high doses without any other purification step than a simple precipitation. These comb-shaped PEG-based polymers may represent an ideal platform for the synthesis of PEGylating moieties for proteins and nanoparticles intended to be used in the biomedical field. © 2010 American Chemical Society. Source


Chenal M.,Laboratoire Of Physico Chimie | Boursier C.,Plate forme Transcriptome proteome | Guillaneuf Y.,CNRS Chemistry Laboratory | Taverna M.,Laboratoire Of Physico Chimie | And 2 more authors.
Polymer Chemistry | Year: 2011

Well-defined fluorescent, α-functional polymethacrylates with PEG side chains were readily designed by nitroxide-mediated polymerization (NMP) from N-hydroxysuccinimidyl (NHS) ester-containing alkoxyamines based on the nitroxide SG1. These polymers were obtained without any purification beyond a simple precipitation. They exhibited tunable reactivities towards nucleophiles depending on the nature of the alkoxyamine used. Copolymers derived from the commercially available SG1-based alkoxyamine led to quantitative coupling with small molecules and a neuroprotective peptide whereas partial conjugation was obtained with lysozyme, used here as a model protein. Complete conjugation to the latter was obtained from similar copolymers exhibiting a less sterically hindered NHS extremity, via appropriate alkoxyamine structure, which represents the very first example of peptide/protein PEGylation with functional polymers derived from NMP. © 2011 The Royal Society of Chemistry. Source

Discover hidden collaborations