CNRS Macromolecular Chemistry and Physics Laboratory

Nancy, France

CNRS Macromolecular Chemistry and Physics Laboratory

Nancy, France
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Gref R.,CNRS Macromolecular Chemistry and Physics Laboratory | Domb A.,Hebrew University of Jerusalem | Quellec P.,CNRS Macromolecular Chemistry and Physics Laboratory | Blunk T.,University of Kiel | And 3 more authors.
Advanced Drug Delivery Reviews | Year: 2012

Injectable blood persistent particulate carriers have important therapeutic application in site-specific drug delivery or medical imaging. However, injected particles are generally eliminated by the reticulo-endothelial system within minutes after administration and accumulate in the liver and spleen. To obtain a coating that might prevent opsonization and subsequent recognition by the macrophages, sterically stabilized nanospheres were developed using amphiphilic diblock or multiblock copolymers. The nanospheres are composed of a hydrophilic polyethylene glycol coating and a biodegradable core in which various drugs were encapsulated. Hydrophobic drugs, such as lidocaine, were entrapped up to 45. wt% and the release kinetics were governed by the polymer physico-chemical characteristics. Plasma protein adsorption was drastically reduced on PEG-coated particles compared to non-coated ones. Relative protein amounts were time-dependent. The nanospheres exhibited increased blood circulation times and reduced liver accumulation, depending on the coating polyethylene glycol molecular weight and surface density. They could be freeze-dried and redispersed in aqueous solutions and possess good shelf stability. It may be possible to tailor "optimal" polymers for given therapeutic applications. © 2012.

Parent M.,University of Lorraine | Nouvel C.,CNRS Macromolecular Chemistry and Physics Laboratory | Koerber M.,Free University of Berlin | Sapin A.,University of Lorraine | And 2 more authors.
Journal of Controlled Release | Year: 2013

In situ forming implants (ISI) based on phase separation by solvent exchange represent an attractive alternative to conventional preformed implants and microparticles for parenteral applications. They are indeed easier to manufacture and their administration does not require surgery, therefore improving patient compliance. They consist of polymeric solutions precipitating at the site of injection and thus forming a drug eluting depot. Drug release from ISI is typically divided into three phases: burst during precipitation of the depot, diffusion of drug through the polymeric matrix and finally drug release by system degradation. This review gives a comprehensive overview on (i) the theoretical bases of these three phases, (ii) the parameters influencing them and (iii) the remaining drawbacks which have to be addressed to enlarge their commercial opportunities. Indeed, although some of them are already commercialized, ISI still suffer from limitations: mainly lack of reproducibility in depot shape, burst during solidification and potential toxicity. Nevertheless, depending on the targeted therapeutic application, these shortcomings may be transformed into advantages. As a result, keys are given in order to tailor these formulations in view of the desired application so that ISI could gain further clinical importance in the following years. © 2013 Elsevier B.V.

Pernot M.,University of Lorraine | Vanderesse R.,CNRS Macromolecular Chemistry and Physics Laboratory | Frochot C.,University of Lorraine | Guillemin F.,University of Lorraine | Barberi-Heyob M.,University of Lorraine
Expert Opinion on Drug Metabolism and Toxicology | Year: 2011

Introduction: Although naturally occurring peptides have been widely used as drugs, their rapid in vivo degradation by proteolysis and their interactions at multiple receptors are part of the reason for the limitation of their clinical applications. Areas covered: This paper reviews peptide-metabolizing enzymes in the brain and intestinal brush-border membranes, and discusses potential strategies to improve biological activity, specificity and stability of peptides. The reader will gain, via some examples, an appreciation of the challenges involved in identifying peptides stability to improve their biological properties such as selectivity. Expert opinion: Due to the metabolic process, it is crucial to follow the biodistribution of a peptide drug and/or a peptidic moiety in order to improve its biological properties such as selectivity. To these purposes, pseudopeptides and peptidomimetics preserving the biological properties of native peptides have been developed to increase their resistance to degradation and elimination, bioavailability and selectivity to become good drug candidates. © Informa UK, Ltd.

Mehawed Abdellatif M.,CNRS Macromolecular Chemistry and Physics Laboratory | Mehawed Abdellatif M.,National Research Center of Egypt | Acherar S.,CNRS Macromolecular Chemistry and Physics Laboratory
Tetrahedron Letters | Year: 2017

An efficient and general low-cost method is described to obtain chiral Nβ-Boc protected α-Nα-hydrazino diester building-blocks (orthogonally and non-orthogonally protected diesters) on multi-gram scale (30 mmol) using two successive SN2 reactions. This method is also convenient for the introduction of both polar and nonpolar side chains on the Nα-atom and represents an inexpensive and attractive alternative compared to the more expensive method using commercial oxaziridine reagents for N-amination of α-amino acids. © 2017 Elsevier Ltd

Boyer C.,University of New South Wales | Whittaker M.R.,University of New South Wales | Nouvel C.,University of New South Wales | Nouvel C.,CNRS Macromolecular Chemistry and Physics Laboratory | Davis T.P.,University of New South Wales
Macromolecules | Year: 2010

This paper describes a new approach for the synthesis of hollow functional polymer nanocapsules, which exploits gold nanoparticles as sacrificial templates. Two different functional diblock polymers have been coassembled on the gold nanoparticles prior to gold removal. The block polymers (made by RAFT polymerization) consisted of a biocompatible polymer segment, either (poly(oligoethylene glycol) acrylate, P(OEG-A), or poly(hydroxylpropylacrylamide), P(HPMA) and a cross-linkable segment comprised of an alternating copolymer of styrene (Sty) and maleic anhydride (MA), (Sty-alt-MA). The block copolymers were assembled onto the GNP surfaces using a grafting "onto" methodology exploiting the high affinity of the RAFT end-groups for the gold surface. The anhydride group was utilized to cross-link the polymer layer. Finally, the gold cores were removed using aqua regia without affecting the integrity of the polymers chains or the nanocapsules. All reaction and assembly steps were characterized by employing a range of techniques, such, as TEM, XPS, ATR-FTIR, DLS, and UV-visible spectroscopy. © 2010 American Chemical Society.

Dupayage L.,CNRS Macromolecular Chemistry and Physics Laboratory | Nouvel C.,CNRS Macromolecular Chemistry and Physics Laboratory | Six J.-L.,CNRS Macromolecular Chemistry and Physics Laboratory
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2011

The synthesis of amphiphilic dextran-g-poly(methyl methacrylate) glycopolymers (Dex-g-PMMA) is studied using "grafting from" concept and atom transfer radical polymerization. Two strategies have been examined to control the macromolecular parameters of such glycopolymers. One is involving four steps including a protection/deprotection approach and the second one only two steps. The introduction of initiators group onto a protected acetylated dextran (and directly onto dextran) was achieved resulting in protected DexAcBr (and in unprotected DexBr). These two types of polysaccharidic macroinitiators differ in term of solubility (hydrophilic DexBr vs. hydrophobic DexAcBr) and of position of the initiators groups on the glucosidic units (which are the sites of the future grafts). When evaluated as macroinitiators for ATRP of MMA, control was achieved in both cases but DexBr gave much faster polymerization and lower average grafting efficiency compared with DexAcBr or model initiator. Advantages and drawbacks of both pathways have finally been discussed. Copyright © 2010 Wiley Periodicals, Inc.

Duval C.,CNRS Macromolecular Chemistry and Physics Laboratory | Nouvel C.,CNRS Macromolecular Chemistry and Physics Laboratory | Six J.-L.,CNRS Macromolecular Chemistry and Physics Laboratory
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2014

Poly(d,l-lactide-co-glycolide) (PLGA) copolyesters are commonly used in biomedical applications. Researches were carried out on nontoxic or low-toxic catalysts that are enough efficient to provide short polymerization times, adequate microstructure chains and similar properties than the commercial PLGA materials. In this study, PLGA were synthesized by ring-opening copolymerization (ROP) using three different catalysts. Stannous octoate is the first catalyst we used, as it is very efficient, even its toxicity is still on debate. Two others low-toxic catalysts [zinc lactate and bismuth subsalicylate (BiSS)] were also evaluated. The comparison of these ROP was realized in terms of kinetics and control of the polymerization. Then, the influence of the catalyst on the PLGA microstructure chains is reported. Finally, abiotic hydrolytic degradation rate is studied. Results described in this article show that BiSS is one very attractive catalyst to produce low toxic PLGA for biomedical applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1130-1138 Three catalysts (SnOct2, ZnLac2, and BiSS) are compared to produce poly(D,L-lactide-co-glycolide) (PLGA). The linear evolution of Ln([M]0/[M]t) versus time is observed until 95% in the case of bismuth subsalicylate ring-opening (co)polymerization (BiSS-ROP). 13C NMR reveals that PLGA with "short block" microstructures are obtained, and, more precisely, that SnOct2 and BiSS lead to a similar microstructure. Finally, the hydrolytic degradation profile of PLGA depends on their chemical composition, and on the microstructure and catalyst used. Copyright © 2014 Wiley Periodicals, Inc.

Sadtler V.,University of Lorraine | Rondon-Gonzalez M.,University of Lorraine | Acrement A.,University of Lorraine | Choplin L.,University of Lorraine | Marie E.,CNRS Macromolecular Chemistry and Physics Laboratory
Macromolecular Rapid Communications | Year: 2010

This study reports the first PEO-coated polymer nanoparticles synthesis by miniemulsion polymerization of nano-emulsions prepared by the low-energy emulsification method called EIP. The surfactant used was Brij 98, a PEO based non ionic commercial surfactant. The partial phase diagram of the system water/Brij 98/styrene was first determined. The Emulsion Inversion Point technique was then used on the water/Brij 98/styrene system to the formation of styrene-in-water nano-emulsions. After miniemulsion polymerization, particle sizes as low as 36 nm were obtained. To the best of our knowledge, this method had not been used for polymerizable system up to now. (Figure Presented) © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Allix F.,CNRS Macromolecular Chemistry and Physics Laboratory | Curcio P.,CNRS Macromolecular Chemistry and Physics Laboratory | Pham Q.N.,CNRS Macromolecular Chemistry and Physics Laboratory | Pickaert G.,CNRS Macromolecular Chemistry and Physics Laboratory | Jamart-Gregoire B.,CNRS Macromolecular Chemistry and Physics Laboratory
Langmuir | Year: 2010

A comparative IR and NMR study of two low-molecular-weight organogels (LMWGs) based on aminoacid derivatives let us point out the hierarchy of the gelation assembly process. Different association states of corresponding organogelator molecules can be observed leading to the supramolecular organization of gel. A first hydrogen bond network of gelators leads to the formation of "head-to-tail" stacking-up, which can be assembled afterward one to the other by π-π stacking interactions. These small supramolecular aggregates (incipient precursor) are still visible in NMR spectra, and they represent, for example, 36% of the total amount of gelator in the case of the L-phenylalanine derivative (gelator 1) at 1 wt % in toluene. Finally, in the last step, the incipient precursor tends to form the expected 3D fibrillar network responsible for the gelation phenomenon. Temperature- dependent IR and NMR experiments allowed us to identify these different states clearly. © 2010 American Chemical Society.

Moulay S.,CNRS Macromolecular Chemistry and Physics Laboratory
Progress in Polymer Science (Oxford) | Year: 2010

Poly(vinyl chloride) (PVC) has continued to be a research topic in polymer science since its discovery in the early 19th century. Its internal structural defects, which stem from its direct manufacture (via free radical polymerization), heighten its peculiarities, including its thermal instability. Apart from the addition of organic and inorganic thermal stabilizers, improved chemistry in the formation of PVC has been proposed to alleviate some of its intrinsic limiting properties. This chemistry, mainly via the chemical transformations of this polymeric material, has been broadened by widespread ongoing research. The so-called anomalous or labile chlorine atoms, that is, the tertiary and allylic chlorines, and the normal secondary ones coupled with a varying content of carbon-carbon double bonds, have been subjected to numerous chemical modifications. The latter were undertaken not only for routine chemical reactions, but also for the sake of enhancing the properties, understanding PVC-related phenomena, and the use of PVC in specific applications. The different reactions on PVC, basically dechlorination, involved nucleophilic and radical substitutions, elimination or dehydrochlorination, and grafting polymerizations via cationic and free radical pathways (old processes or new ones, ATRP and LCRP). Leading and attractive applications of the chemically modified PVCs were ion-selective electrode membranes, membrane sensors, and biomedical devices. In this paper, an account of many of the chemical modifications of PVC based on reports over the last decade is delineated, along with related applications. These modifications are presented according to the bond formed (CPVC-X) between the PVC carbon CPVC and the atom X (X = N, O, S, Hal) of the modifying molecule. © 2009 Elsevier Ltd. All rights reserved.

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