Pierre Chaminade
Université Paris-Saclay
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Featured researches published by Pierre Chaminade.
International Journal of Pharmaceutics | 2001
Irène Brigger; Pierre Chaminade; Véronique Marsaud; Martine Appel; Madeleine Besnard; Robert Gurny; Michel Renoir; Patrick Couvreur
When dealing with solid tumors in vivo, pegylated long-circulating carrier systems show, after intravenous administration, an attractive extravasation profile with an enhanced localization in the tumoral interstitium. These systems could be of help for the delivery of cancer fighting drugs, such as Tamoxifen, a well known antiestrogen used in breast cancer therapy that possesses an extended biodistribution in vivo. This work aimed at encapsulating Tamoxifen in long-circulating poly(MePEGcyanoacrylate-co-hexadecylcyanoacrylate) 1:4 nanospheres. Tamoxifen-loaded poly(MePEGcyanoacrylate-co-hexadecylcyanoacrylate) nanospheres were successfully synthesized and characterized in terms of hydrophilicity/hydrophobicity by a model made up from near infrared spectra using principal component analysis. Zeta potential, drug loading, encapsulation efficiency, as well as biological effect, in vitro release and nanospheres integrity were also investigated. Even though near infrared spectroscopy could not detect Tamoxifen, it revealed that Pluronic F68 was associated with the pegylated nanospheres. HPLC measurements demonstrated that Tamoxifen was encapsulated in the pegylated nanospheres following a partition equilibrium between the polymeric and the aqueous phases. The Tamoxifen encapsulated in the nanospheres still showed a transcription inhibitory activity in ex vivo experiments. However, zeta potential and in vitro release suggested that Tamoxifen was essentially localized at the nanoparticles surface, resulting in an important and immediate drug release.
Biomaterials | 2010
Raquel Díaz-López; Nicolas Tsapis; Mathieu Santin; S. Bridal; Valérie Nicolas; Danielle Jaillard; Danielle Libong; Pierre Chaminade; Véronique Marsaud; Christine Vauthier; Elias Fattal
The surface of polymeric nanocapsules used as ultrasound contrast agents (UCAs) was modified with PEGylated phospholipids in order to escape recognition and clearance by the mononuclear phagocyte system and achieve passive tumor targeting. Nanocapsules consisted of a shell of poly(lactide-co-glycolide) (PLGA) encapsulating a liquid core of perfluorooctyl bromide (PFOB). They were decorated with poly(ethylene glycol-2000)-grafted distearoylphosphatidylethanolamine (DSPE-PEG) incorporated in the organic phase before the solvent emulsification-evaporation process. The influence of DSPE-PEG concentration on nanocapsule size, surface charge, morphology, hydrophobicity and complement activation was evaluated. Zeta potential measurements, Hydrophobic interaction chromatography and complement activation provide evidence of DSPE-PEG presence at nanocapsule surface. Electronic microscopy reveals that the core/shell structure is preserved up to 2.64 mg of DSPE-PEG for 100 mg PLGA. In vivo ultrasound imaging was performed in mice bearing xenograft tumor with MIA PaCa-2 cells, either after an intra-tumoral or intravenous injection of nanocapsules. Tumor was observed only after the intra-tumoral injection. Despite the absence of echogenic signal in the tumor after intravenous injection of nanocapsules, histological analysis reveals their accumulation within the tumor tissue demonstrating that tissue distribution is not the unique property required for ultrasound contrast agents to be efficient.
Pharmaceutical Research | 2000
Irène Brigger; Pierre Chaminade; Didier Desmaële; Maria Teresa Peracchia; Jean d'Angelo; Robert Gurny; Michel Renoir; Patrick Couvreur
AbstractPurpose. To progress in the characterization of a poly(MePEGcyanoacrylate-co-hexadecylcyanoacrylate) (poly(PEGCA-co-HDCA) copolymer and the nanoparticles formed from this copolymer. Methods. Poly(PEGCA-co-HDCA) at a MePEG/hexadecyl ratio of 1:4 was investigated by 1H-NMR and near infrared spectroscopy. The nanoparticle suspensions, obtained by the methods of nanoprecipitation or emulsion—solvent evaporation, as well as the crude nanoparticles and their dispersion medium—were analyzed by MePEG measurement, 1H-NMR, and near infrared spectroscopy. Results. The 1H-NMR results showed that the (poly(PEGCA-co-HDCA) copolymer obtained bore lateral hydrophilic MePEG chains and lateral hydrophobic hexadecyl chains in a final ratio of 1:4. However, this ratio, although reproducible from batch to batch, represented only a mean value for different molecular species. Indeed, our results demonstrated the formation of more hydrophobic poly(alkylcyanoacrylate) oligomers (with a higher content of hexadecyl chains) and other more hydrophilic oligomers (with a higher MePEG content). Only the more hydrophobic oligomers were able to form solid pegylated nanoparticles. As far as these nanoparticles were concerned, determination of their MePEG content allowed the calculation of a distance of 1.2 nm and 1.05 nm between 2 grafted MePEG chains at the nanoparticle surface, when obtained by nanoprecipitation and emulsion-solvent evaporation, respectively. Moreover, when the same copolymer batch was used, different nanoparticles were obtained according to the preparation method, as seen by near infrared spectroscopy. Conclusions. The nanoparticles obtained by nanoprecipitation or emulsion-solvent evaporation of poly(PEGCA-co-HDCA) 1:4 copolymer displayed a different supramolecular organization, as evidenced by the near infrared spectroscopy results. Moreover, these nanoparticles showed surface characteristics compatible with a long circulating carrier.
Tetrahedron Letters | 1999
Rosana Alvarez; Marie-Agnès Hourdin; Christian Cavé; Jean d'Angelo; Pierre Chaminade
New polymer-supported catalysts derived from quinine and quinidine were elaborated and tested in the conjugate addition between enamino ester 13 and methyl vinyl ketone. By employing a 7-atom-length spacer, an excellent enantioselectivity was observed (87%).
Analytical and Bioanalytical Chemistry | 2012
L. Imbert; D. Libong; S. Abreu; P. M. Loiseau; Pierre Chaminade
Leishmaniasis is a widespread parasitic disease principally treated by intravenous drugs. Hexadecylphosphocholine (miltefosine) has recently proved its efficacy by oral route. Although its mechanism of action has been investigated, and principally relies on perturbations of the metabolism of lipids and especially phospholipids, further studies need to be conducted to detect precisely which metabolic pathways are impacted. For this purpose, the present work proposes a complete lipidomic study focused on membrane phospholipids of clones of Leishmania donovani non-treated (NT), treated (T) and resistant (R) to miltefosine. Firstly, a separation of phospholipids in normal phase high-performance liquid chromatography (NP-HPLC) was coupled to a mass spectrometer (MS) equipped with an electrospray (ESI) ion source, and response was compared to evaporative light scattering detection (ELSD). Secondly, a quantification of phospholipid classes was performed using NP-HPLC/ESI/MS on NT, T and R clones of L. donovani. Thirdly, full-scan acquisitions of analyzed samples were compared using orthogonal signal correction-partial least square-discriminant analysis (OSC-PLS-DA) to highlight phospholipid molecular species of interest between the three types of clones. Structural determination of the most relevant species has finally been performed using tandem mass spectrometry. A first hypothesis on the effect of miltefosine on lipid metabolic pathways is then proposed.
European Journal of Pharmaceutical Sciences | 2011
Claire Gendre; Muriel Genty; Mathieu Boiret; Marc Julien; Loïc Meunier; Olivier Lecoq; Michel Baron; Pierre Chaminade; Jean Manuel Pean
The aim of this study was to perform in-line Near Infrared (NIR) measurements inside a pan coater to monitor a coating operation in real-time, by predicting the increases in mass of coating materials and coating thickness. A polymer combination of ethylcellulose/poly(vinyl-alcohol)-poly(ethylene-glycol) graft copolymer was used as functional aqueous coating. Coated tablets were sampled at regular intervals during the coating operation, then subjected to either simple and fast weighing (n=50) or accurate and non-destructive Terahertz Pulsed Imaging (TPI) measurements (n=3). Off-line NIR spectra analysis revealed that the coating operation could efficiently be controlled by focusing on two distinct NIR regions, related to absorption bands of ethylcellulose. Principal component analysis of in-line NIR spectra gave a clear classification of the collected coated tablets. Real-time quantitative monitoring of the coating operation was successfully performed from partial least square calibration models built using either TPI or weighing as reference method. Coating thicknesses as well as mass of coating materials used as primary values provided accurate NIR predictions. A comparison study demonstrated that both reference methods led to reliable and accurate real-time monitoring of the coating operation. This work demonstrated that in-line NIR measurements associated with multivariate analyses can be implemented to monitor in real-time a pan coating operation in order to fulfil the expectations of ICH Q8 guideline on pharmaceutical development, especially in terms of PAT control strategy and reduced end-product testing.
Analyst | 2002
Frantz S. Deschamps; Arlette Baillet; Pierre Chaminade
Triethylamine with an equimolar amount of formic acid added to the mobile phase provides an enhancement of the evaporative light scattering detector (ELSD) response. After characterization of the influence of various parameters on the ELSD response, a sequential strategy was defined to elucidate this response enhancement. The response enhancement was more marked at low mobile phase flow rate, and was highly dependent on solutes and solvents. The influence of drift tube temperature on response enhancement with various solutes demonstrated that triethylamine and formic acid mainly act as mass amplifiers by the inclusion of triethylamine-formic acid clusters inside the droplets.
Journal of Chromatography A | 2001
Frantz S. Deschamps; Pierre Chaminade; Danielle Ferrier; Arlette Baillet
Potentialities of polymerized vinyl alcohol on silica gel were assessed for class separation of simple lipids, sphingolipids, glyceroglycolipids and phospholipids by high-performance liquid chromatography. A screening of pure solvents in binary gradient elution and a chemometric approach was used to define a rugged two segment linear gradient formed from four solvents for total lipid class separation. Triethylamine and formic acid were added in all mobile phase components for acidic phospholipid separation and evaporative light scattering response enhancement. Simple analytical procedures are described for the analysis of complex lipid materials.
Biomaterials | 2009
Raquel Díaz-López; Nicolas Tsapis; Danielle Libong; Pierre Chaminade; Carole Connan; Mohamed M. Chehimi; Romain Berti; Nicolas Taulier; W. Urbach; Valérie Nicolas; Elias Fattal
We present here an easy method to modify the surface chemistry of polymeric microcapsules of perfluorooctyl bromide used as ultrasound contrast agents (UCAs). Capsules were obtained by a solvent emulsification-evaporation process with phospholipids incorporated in the organic phase before emulsification. Several phospholipids were reviewed: fluorescent, pegylated and biotinylated phospholipids. The influence of phospholipid concentration on microcapsule size and morphology was evaluated. Only a fraction of the phospholipids is associated to microcapsules, the rest being dissolved with the surfactant in the aqueous phase. Microscopy shows that phospholipids are present within the shell and that the core/shell structure is preserved up to 0.5 mg fluorescent phospholipids, up to about 0.25 mg pegylated phospholipids or biotinylated phospholipids (for 100 mg of polymer, poly(lactide-co-glycolide) (PLGA)). HPLC allows quantifying phospholipids associated to capsules: they correspond to 10% of pegylated phospholipids introduced in the organic phase. The presence of pegylated lipids at the surface of capsules was confirmed by X-ray photon electron spectroscopy (XPS). The pegylation did not modify the echographic signal arising from capsules. Finally biotinylated microcapsules incubated with neutravidin tend to aggregate, which confirms the presence of biotin at the surface. These results are encouraging and future work will consist of nanocapsule surface modification for molecular imaging.
Journal of Controlled Release | 1996
C. Laugel; Pierre Chaminade; A. Baillet; M Seiller; D. Ferrier
The purpose of this paper was to prove the efficiency of suitable tracer incorporation in the aqueous inner phase for multiple emulsion studies. The use of dihydralazine as tracer allowed the evaluation of both the yield of preparation and the stability of eight multiple emulsions. In these, concentrations of several components were optimized i.e. oil, lipophilic and hydrophilic emulsifiers, coemulsifier and viscosity increasing agent. From entrapment data and droplet breakdown curves, calculated from the dihydralazine chromatographic data, one emulsion was selected to study the release of some encapsulated moisturizing solutes such as urea, chitosan and polyethylene glycol. Dihydralazine proved of value to discriminate between the two mechanisms responsible for the solute release i.e. the breakdown of the multiple droplets and the diffusion of the solute through the oil layer. Diffusion curves were obtained from the levels of moisturizing substance in the outer aqueous phase, corrected by the amounts liberated by the droplet breakdown calculated through dihydralazine levels. The lipophilicity of the solutes measured under conditions similar to those partitionning in the emulsions correlated with the diffusional route of solute transfer. Thus, the partition coefficient was an efficient parameter to predict the importance and the rate of the diffusion.