Showing papers by "Julien Nicolas published in 2009"

Synthesis of poly(alkyl cyanoacrylate)‐based colloidal nanomedicines

Abstract: Nanoparticles developed from poly(alkyl cyanoacrylate) (PACA) biodegradable polymers have opened new and exciting perspectives in the field of drug delivery due to their nearly ideal characteristics as drug carriers in connection with biomedical applications. Thanks to the direct implication of organic chemistry, polymer science and physicochemistry, multiple PACA nanoparticles with different features can be obtained: nanospheres and nanocapsules (either oil- or water-containing) as well as long-circulating and ligand-decorated nanoparticles. This review aims at emphasizing the synthetic standpoint of all these nanoparticles by describing the important aspects of alkyl cyanoacrylate chemistry as well as the experimental procedures and the different techniques involved for the preparation of the corresponding colloidal devices. Copyright © 2008 John Wiley & Sons, Inc. For further resources related to this article, please visit the WIREs website.

Comprehensive Modeling Study of Nitroxide-Mediated Controlled/Living Radical Copolymerization of Methyl Methacrylate with a Small Amount of Styrene

Abstract: This article presents a comprehensive kinetic study of the SG1 nitroxide-mediated copolymerization of methyl methacrylate with a small percentage of styrene using the PREDICI software. The aim of this study was to confirm the results from a previous publication showing that a living polymerization can be achieved for this system. The PREDICI simulations based on the penultimate unit effect model were also able to give a better insight into the complex mechanism of nitroxide-mediated controlled radical copolymerization. The model showed the copolymerization kinetics and the evolution of the number average molar mass, the fraction of living and dead chains, and the concentration of the four types of alkoxyamines and propagating radicals with monomer conversion. It was applied for different initial percentages of styrene and different initiator concentrations.

Application of thermal analysis to the study of lipidic prodrug incorporation into nanocarriers

Abstract: Anti HIV molecules as numerous drugs cannot efficiently penetrate into the brain. Prodrug synthesis and encapsulation into pegylated nanocarriers have been proposed as an approach for brain delivery. Pegylated polymeric nanoparticles and liposomes were chosen to incorporate glycerolipidic prodrugs of didanosine. Differential scanning calorimetry experiments were performed on mixtures of prodrugs and lipids or polymer in order to study their interaction. The optimal incorporation ratios were determined for each prodrug and compared for both types of nanocarriers. All these results would be used to prepare optimised formulations of didanosine prodrugs loaded into pegylated nanocarriers for brain drug delivery.

Nitroxide-Mediated Controlled Free-Radical Copolymerization of Poly(ethylene glycol) Methyl Ether Methacrylate and Methacrylic Acid. Toward New Water-Soluble Macroinitiators

Abstract: New water-soluble macroalkoxyamines were synthesized via nitroxide-mediated controlled free-radical copolymerization of poly(ethylene glycol) methyl ether methacrylate with a low percentage of styrene and terpolymerization with methacrylic acid at a temperature below 80 °C. They were employed as macroinitiators for the synthesis of amphiphilic block copolymers, either in bulk or in aqueous emulsion polymerization. In the latter process, PEG-coated, amphiphilic diblock copolymer micelles were generated in situ.