Stratégies de délivrance cellulaire de nanomédicaments antiviraux

La chimiothérapie antivirale repose majoritairement sur les analogues nucléosidiques : à eux seuls, ils représentent à l heure actuelle la moitié des médicaments antiviraux approuvés par la FDA. Cependant, bien que largement utilisés en clinique, les analogues nucléosidiques peuvent présenter d importantes limites, se traduisant par l apparition d effets secondaires graves et de résistance aux traitements. Afin d améliorer l efficacité des analogues nucléosidiques, nous avons étudié au cours de cette thèse deux stratégies de délivrance cellulaire basées sur l utilisation de nanotechnologies : la de livrance d analogues nucléosidiques triphosphorylés à l aide de nanocapsules polymères, ainsi que la délivrance cellulaire d analogues nucléosidiques squalénisés .Antiviral chemotherapy mostly lies on nucleoside analogues, which currently represent the majority of FDA-approved antiviral medicines. However, despite their extensive clinical use, nucleoside analogues exhibit some important limitations, such as severe side effects and resistances.In order to improve the efficacy of nucleoside analogues, we have studied two different strategies of cellular delivery based on nanotechnologies : on the one hand, the delivery of triphosphorylated nucleoside analogues using polymeric nanocapsules, on the other hand, the delivery of squalenated nucleoside analogues.CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Stability, pharmacokinetics, and biodistribution in mice of the EPAC1 inhibitor (R)-CE3F4 entrapped in liposomes and lipid nanocapsules

International audienc

Interspecies comparison of plasma metabolism and sample stabilization for quantitative bioanalyses: Application to (R)-CE3F4 in preclinical development, including metabolite identification by high-resolution mass spectrometry

International audienc

Nanotoxicology at the particle/micelle frontier: influence of core-polymerization on the intracellular distribution, cytotoxicity and genotoxicity of polydiacetylene micelles

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Pulmonary surfactant protein A-mediated enrichment of surface-decorated polymeric nanoparticles in alveolar macrophages

Surfactant protein A (SP-A), a lung anti-infective protein, is a lectin with affinity for sugars found on fungal and micrococcal surfaces such as mannose. We synthesized a mannosylated poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) copolymer and used it to produce nanoparticles with a polyester (PLGA/PLA) core and a PEG shell decorated with mannose residues, designed to be strongly associated with SP-A for an increased uptake by alveolar macrophages. Nanoparticles made of the copolymers were obtained by nanoprecipitation and displayed a size of around 140 nm. The presence of mannose on the surface was demonstrated by zeta potential changes according to pH and by a strong aggregation in the presence of concanavalin A. Mannosylated nanoparticles bound to SP-A as demonstrated by dynamic light scattering and transmission electron microscopy. The association with SP-A increased nanoparticle uptake by THP-1 macrophages in vitro. In vivo experiments demonstrated that after intratracheal administration of nanoparticles with or without SP-A, SP-A-coated mannosylated nanoparticles were internalized by alveolar macrophages in greater proportion than SP-A-coated nonmannosylated nanoparticles. The data demonstrate for the first time that the pool of nanoparticles available to lung cells can be changed after surface modification, using a biomimetic approach.German Research Foundation (DFG)Depto. de Bioquímica y Biología MolecularFac. de Ciencias BiológicasFac. de Ciencias QuímicasTRUEpu

Hyaluronic acid-bearing lipoplexes: physico-chemical characterization and in vitro targeting of the CD44 receptor.

International audienceThe mechanism by which hyaluronic acid (HA)-bearing lipoplexes target the A549 lung cancer cell line was evaluated. For this purpose, cationic liposomes targeting the CD44 receptor were designed thanks to the incorporation in their composition of a conjugate between high molecular weight HA and the lipid DOPE (HA-DOPE). Liposomes containing HA-DOPE were complexed at different lipids:DNA ratios with a reporter plasmid encoding the green fluorescent protein (GFP). Diameter, zeta potential, lipoplex stability and DNA protection from nucleases have been determined. Lipids:DNA ratios of 2, 4 and 6 provided a diameter around 250 nm with a zeta potential of -30 mV. The strength of lipids:DNA interaction and the fraction of DNA protected from enzymatic degradation increased with the lipids:DNA ratio. 2D-immunoelectrophoresis demonstrated the low capacity to activate the C3 fraction of the complement system of any of these three ratios, with and without HA-DOPE. Transfection efficiency in the presence of 0, 10 and 15% of HA-DOPE or unconjugated HA, was determined on the CD44-expressing A549 cells by flow cytometry. Lipoplexes at a lipids:DNA ratio of 2 containing 10% (w/w) of HA-DOPE were the most efficient for transfection. The maximal level of GFP expression was obtained after 6h of incubation demonstrating a slow transfection kinetics of lipoplexes. Finally, lipoplex cellular uptake, measured indirectly by the level of transfection using flow cytometry and validated by fluorescence microscopy, was shown to be mediated by the CD44 receptor and caveolae. These results demonstrate the strong specificity of DNA targeting through the CD44 receptor using HA of high molecular weight as a ligand

Resolution of MoS2 nanosheets-induced pulmonary inflammation driven by nanoscale intracellular transformation and extracellular-vesicle shuttles

Pulmonary exposure to some engineered nanomaterials can cause chronic lesions as a result of unresolved inflammation. Among two-dimensional (2D) nanomaterials and graphene, MoS2 have received tremendous attention in optoelectronics and nanomedicine. Here we propose an integrated approach to follow up the transformation of MoS2 nanosheets at the nanoscale and their impact on the lung inflammation status over one month after a single inhalation in mice. Analysis of immune cells, alveolar macrophages, extracellular vesicles, and cytokine profiling in bronchoalveolar lavage fluid (BALF) showed that MoS2 nanosheets induced initiation of lung inflammation that was rapidly resolved despite the persistence of various biotransformed molybdenum-containing nanostructures in alveolar macrophages and extracellular vesicles up to one month. Using in situ liquid phase transmission electron microscopy experiments, we could evidence the dynamics of MoS2 nanosheets transformation triggered by reactive oxygen species. Three main transformation mechanisms were observed directly at the nanoscale level: 1) scrolling of the dispersed sheets leading to the formation of nanoscrolls and folded patches, 2) etching releasing soluble MoO4-, and 3) oxidation generating oxidized sheet fragments. Extracellular vesicles released in BALF were also identified as a potential shuttle of MoS2 nanostructures and their degradation products and more importantly as mediators of inflammation resolution