Дисертації з теми "Nanoparticels"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Nanoparticels".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Barbero, Francesco. "Physicochemical characterization of the evolution of metal nanoparticles in biological and environmental media: from synthesis to interaction with living organisms." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/670187.
Повний текст джерелаLa creciente producción de nanopartículas (NP) conducirá inevitablemente a un aumento de la exposición humana y ambiental a estos materiales. En consecuencia, han surgido preocupaciones razonables con respecto a sus posibles riesgos de seguridad, dando lugar a la disciplina de nanotoxicología/nanoseguridad. Debido a la alta reactividad, los NP expuestos a diferentes escenarios biológicos y ambientales tienden a alcanzar un estado termodinámico más estable a través de la agregación, la interacción con las moléculas presentes en el medio ambiente, la adsorción a la materia macro-orgánica, las transformaciones químicas y la disolución. Todas estas transformaciones pueden generar una nueva identidad de los nanoobjetos o producir nuevas entidades químicas, cambiando así su comportamiento y, en consecuencia, su riesgo asociado potencial. Por lo tanto, los mismos NP pueden tener un destino totalmente diferente y, en consecuencia, un impacto totalmente diferente en los organismos vivos y el medio ambiente dependiendo del microambiente (por ejemplo, el medio de exposición) en el que se encuentran. Además, las características prístinas del nanomaterial influyen mucho en su destino biológico y medioambiental. Desde esta perspectiva, resulta fundamental comprender las características del objeto final que encontrará organismos vivos y analizar sus propiedades, a fin de correlacionar las características de NP prístinas y finales con los posibles efectos sobre los organismos vivos. En este contexto, el objetivo de esta tesis ha sido el estudio de la transformacion fisicoquímico de NP modelo expuestos a medios biológicos y ambientales. Para estos estudios, se eligieron NPs de Au y Ag, ya que son modelos de NP ampliamente utilizados y debido a sus numerosas aplicaciones. En primer lugar, el estudio se centró en la influencia de la composición de los medios de cultivo celular en el proceso de formación de protein corona, la composición final y el estado de agregación de NP y los efectos consiguientes en la absorción de células NP. También se realizó una caracterización fisicoquímica de la naturaleza de la bicapa CTAB - Au NP para estudiar el impacto de este recubrimiento de superficie NP ampliamente utilizado en la exposición de la partícula a los fluidos biológicos, en la formación de la corona de proteínas y en el diseño e interpretación de Pruebas de toxicidad NP. Finalmente, la evolución de NP en agua dulce natural se exploró mediante la realización de un estudio de la naturaleza de interacción de NP y materia orgánica natural y las características derivadas de NP.
The increasing production of engineered Nanoparticles (NPs) will inevitably lead to an increase of human and environmental exposition to these materials. Consequently reasonable concerns have arisen regarding their potential safety risks, giving rise to the nanotoxicology/nanosafety discipline. Because of the high reactivity, NPs exposed to different biological and environmental scenarios, tend to reach a more stable thermodynamic state via aggregation, interaction with the molecules present in the environment, adsorption to macro-organic matter, chemical transformations and dissolution. All these transformations can generate a new identity of the nano-objects or produce new chemical entities, thereby changing their behaviour and consequently their potential associated risk. Thus, the same NPs can have a totally different fate and consequently a totally different impact on living organisms and the environment depending on the microenvironment (e.g., the exposure medium) in which they are. Furthermore, the pristine features of nano-material highly influence their biological and environmental fate. From this perspective, it becomes fundamental to understand the characteristics of the final object that will encounter living organisms and analyze its properties, in order to correlate the pristine and final NP features with the potential effects on living organisms. In this context, the focus of this thesis has been on the physicochemical transformation of model NPs exposed to biological and environmental media. For these studies, Au and Ag NPs were chosen as they are widely used NP models and because of their numerous applications. Firstly, the study focused on the influence of the cell culture media composition on the protein corona (PC) formation process, final composition and NPs aggregation state and the consequent effects on NP cell uptake. A physicochemical characterization of the nature of the CTAB - Au NP bilayer was also carried out to study the impact of this widely used NP surface coating on the particle’s exposition to biological fluids, on the formation of the protein corona and on the design and interpretation of NP toxicity tests. Finally, the NP evolution in natural fresh water was explored by carrying out a study of the interaction nature of NPs and natural organic matter and the deriving NP features.
Lemaître, Caroline. "Contribution à l'étude théorique, numérique et expérimentale des nanoantennes patch optiques." Thesis, Clermont-Ferrand 2, 2016. http://www.theses.fr/2016CLF22742/document.
Повний текст джерелаIn the field of biosensors, efficient absorption of the electromagnetic field in a confined space is essential. The use of metallic nanoparticules comparable to metamaterials is the best way, to date, to amplify the field. In fact, by placing a dielectric film between a metal substrate and these particules, we allow the propagation of a gap-plasmon under these particules. This locates the magnetic field under these particules and the electric field on the edges of these nanoparticules. The resonances of this system are very sensitive to the environment of the gap-plasmon which allows very precise analysis. Although we can explain where these resonances come from, the efficiency to absorb of these structures remains poorly understood. The interferometric control is a response to this efficiency. In this report, I show that interferometric modeling of this system can fully explain the absorption. Indeed, the interferometric control well explains the presence of resonances at specific wavelenghts or the appearance of resonances when the angle of incidence is not normal. This study is very important to understand and master biosensors. In addition, this model can explain the amplification of the field in these structures and will allow us to provide the resonances of a system in various environments
Díaz, Ocaña Raquel. "Recombinant self-assembling nanoparticles for cancer therapy based on toxin and venom compounds." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670483.
Повний текст джерелаLa plataforma desarrollada de ingeniería de proteínas autoensamblables permite diseñar nanopartículas únicamente proteicas (NPs) capaces de atacar y actuar selectivamente sobre las células cancerosas mediante la interacción con receptores que se sobreexpresan. Las estructuras esféricas estables de las NPs desarrolladas y su tamaño adecuado, en combinación con los péptidos de direccionamiento involucrados, mejoran su especificidad. Además, la novedosa incorporación de segmentos de toxina y veneno ha mejorado los efectos terapéuticos de estas estructuras que son totalmente biocompatibles y que no tienen ningún portador externo o material agregado, cumpliendo de esta manera con el concepto emergente para medicamentos de precisión que involucra un fármaco recombinante libre de vehículo, autoensamblado, auto-dirigido y eficiente. Una versión modificada de la cadena catalítica de ricina A, con la capacidad de disminuir los efectos secundarios no deseados del síndrome de derrame vascular, pero conservando su citotoxicidad natural, se adaptó a la plataforma de proteínas. El diseño se desarrolló con el péptido T22, que se une a CXCR4, en el extremo N-terminal, y una cola de histidinas en el extremo C-terminal, en combinación con un fragmento del sitio escindible de furina para liberar la proteína intracelularmente, y una secuencia KDEL para evitar secreción del retículo endoplásmico. Las NPs de cadena de ricina A solubles purificadas dirigidas a CXCR4, con un diámetro promedio de 11 nm, alcanzaron un incremento de 100 veces en su citotoxicidad con un IC50 de 13 ± 0,5 x 10 -9 M en células HeLa. Pero también se produjeron por métodos recombinantes y se purificaron cuerpos de inclusión insolubles de 400-600 nm, con resultados citotóxicos parciales. El mecanismo de entrada dependiente del receptor de T22-mRTA-H6 se verificó y evaluó en un modelo de ratón con leucemia mieloide aguda (AML) mediante la inyección sistémica en la vena de la cola, donde se verificó un bloqueo importante de las células leucémicas sin toxicidad sistémica o histológica lateral en los órganos sanos. De manera similar, la clorotoxina (CTX) también se incorporó a la plataforma de proteínas con el fin de aprovechar su direccionamiento y efecto terapéutico en glioblastoma (GBM), ambas funciones en un solo péptido. Se diseñaron dos versiones que se unen a la proteína anexina-2 y la metaloproteinasa de matriz MMP-2; CTX-GFP-H6 y CTX-KRKRK-GFP-H6. Lss NPs solubles, de un diámetro promedio de 12 nm, se incubaron en células HeLa sobreexpresando anexina-2, y en células U87MG, sobreexpresando MMP2. Ambas versiones eran completamente fluorescentes, pero CTX-GFP-H6 presentó efectos citotóxicos leves, mientras que CTX-KRKRK-GFP-H6 mostró ser más citotóxico en las células U87MG que en las células HeLa. La afinidad selectiva de CTX se confirmó mediante la evaluación de su direccionamiento utilizando anticuerpos monoclonales y un suero policlonal contra la proteína de la superficie celular, actuando como un receptor de la CTX.
The developed self-assembling platform allows the engineering of protein-only nanoparticles (NPs) capable to target and act selectively over cancer cells by means of the interaction with overexpressed receptors. The stability of the spherical NP structures and their adequate size, in combination with the involved targeting peptides, enhance their specificity. Also, the novel incorporation of toxin and venom segments have improved the therapeutic effects of these fully biocompatible materials, without the need of any external carrier or added material, thus fulfilling the newfangled concept for precision medicines that involve self-assembled, self-targeted and efficient vehicle-free recombinant drugs. A modified version of the catalytic ricin A chain, with the ability to diminish the undesired vascular leak syndrome side effects but retaining its natural cytotoxicity, was adapted to the protein platform. The design was developed with the peptide T22 in the N-terminal, which binds CXCR4, and a his-tag in the C-terminal. This was combined with a furin cleavable site fragment in order to release the protein intracellularly, and a KDEL sequence to avoid endoplasmic reticulum secretion. Purified soluble CXCR4-targeted ricin A chain NPs with an average diameter of 11 nm, reached a 100-fold cytotoxic improvement with an IC50 of 13 ± 0.5 x 10 -9 M in HeLa cells. Also, insoluble 400-600 nm inclusion bodies were produced by recombinant methods and purified, with partial cytotoxic results. The receptor-dependent mechanism of T22-mRTA-H6 was verified and evaluated in an acute myeloid leukemia (AML) mouse model by systemic administration through a vein tail injection where an important blockage of the leukemic cells was verified without side systemic or histological toxicity in healthy organs. In a similar way, chlorotoxin (CTX) was also incorporated to the protein platform in order to take advantage of its targeting and therapeutic effect in glioblastoma (GBM), both functions in one peptide. Two versions that target protein Annexin-2 and the matrix metalloproteinase MMP-2 were engineered, namely CTX-GFP-H6 and CTX-KRKRK-GFP-H6. The soluble NPs of an average dimeter of 12 nm were incubated with HeLa cells, overexpressing annexin-2, and in U87MG cells, overexpressing MMP2. Both versions were fully fluorescent but CTX-GFP-H6 presented mild cytotoxic effects, whereas CTX-KRKRK-GFP-H6 showed to be more cytotoxic in U87MG cells than in HeLa cells. The selective affinity of CTX was confirmed by means of evaluating its targeting using a monoclonal antibody and a polyclonal serum against the cell surface protein, acting as a CTX receptor.
Rousseau, Youri. "Hybridation des technologies de jets de nanoparticules et de PVD pour la réalisation d’architectures nanocomposites fonctionnelles." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS347.
Повний текст джерелаThe nanocomposite films are coatings of nanoparticles embedded in a solid matrix of a different material. The advantage of these materials is their ability to exploit the unique properties of nano-objects while benefiting of the mechanical and chemical resistance properties of the matrix. These composites have very promising properties for many applications such as photovoltaics and photocatalysis. Several existing synthetic methods can produce nanocomposite materials by physical or chemical methods (co-sputtering, sol-gel, ...). However, none is flexible enough to consider the synthesis of a wide range of nanocomposites by the same method. This is an obstacle to the development on an industrial scale of this type of material. The first objective of the thesis is to develop an original synthesis process of nanocomposite films. This method is universal in which it presents no limit in the choice of nanoparticles and matrix. The developed method combines vacuum nanoparticle jets formed by an aerodynamic lens with a magnetron sputtering device for depositing the matrix. The nanoparticle jets can be coupled with any source of nanoparticles. Nanoparticles may be synthesized in situ in the gas phase or beforehand solution synthesis. A wide variety of nanoparticles can be used. Magnetron sputtering also enables to have a very wide range of materials for the matrix (metal, ceramic, polymer). During this thesis, two types of nanoparticles sources were used. The first one is a laser pyrolysis reactor and the second is an aerosol generator. The laser pyrolysis reactor enables in-situ gas phase synthesis of the nanoparticles while the aerosol generator use a suspension of previously synthesized nanoparticles. To test the robustness of the co-deposition process, two types of nanocomposite materials have been developed. The first material is composed of 35 nm spherical gold nanoparticles, chemically synthesized, in a silica matrix. The goal here is to benefit from the unique optical properties of gold nanoparticles in a film mechanically and chemically resistant. The characterizations carried out on these materials have optimized the gold nanoparticle concentration in the films to keep the mechanical and chemical properties compatible with applications while maintaining satisfactory optical properties. The second type of materials studied is composed of semiconductor nanoparticles in situ synthesized by laser pyrolysis and a metal matrix. The synthesis of this material demonstrates the flexibility of the co-deposition method to synthesize a wide variety of nanocomposite films. Finally, the design of an industrial pilot was undertaken. The final goal is to have a pilot-scale setup that meets industry requirements in the context of a technology transfer
Luo, Zhongrui. "In vivo interactions between food availability and nanoparticles in Caenorhabditis elegans." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/671182.
Повний текст джерелаDurante las últimas décadas, las nanopartículas (NPs) se han utilizado ampliamente en distintos campos, especialmente en aplicaciones médicas como fármacos, agentes de formación de imágenes y como liberadores de fármacos. Sin embargo, también han planteado dudas respecto a las posibles reacciones adversas sobre la salud humana. Así, se han realizado grandes esfuerzos de investigación en el campo de las ciencias biológicas para elucidar los mecanismos de toxicidad de distintas NPs. En este trabajo de Tesis, hemos dedicado esfuerzos a aplicar el (Caenorhabditis elegans) C. elegans como un organismo modelo robusto y simple para las evaluaciones de toxicidad de NPs. El objetivo general de esta tesis ha sido estudiar la interacción de la comida de estos gusanos con las NPs. En particular, el estudio de las interacciones nano-bio entre nanopartículas de óxido de hierro superparamagnéticas (SPIONs) o AuNPs de 10 nm en C. elegans alimentados o no; así demostrar que este pequeño animal puede utilizarse para estudiar efectos alimentarios. En primer lugar, estudiamos los efectos de la disponibilidad de alimento sobre las toxicidades inducidas por la exposición de SPIONs tras 24 h - exposición aguda - o 72 h - exposición prolongada. Descubrimos que la comida brinda cierta protección a los C. elegans, la cual se determinó midiendo la supervivencia y la reproducción. Los gusanos en la exposición aguda tuvieron una mayor eficiencia de absorción de SPIONs facilitada por la comida en comparación con la condición sin alimento. La utilización de la microespectroscopía infrarroja de Sincrotrón (SR-μFTIR) nos permitió demostrar que la exposición prolongada (24 h versus 4 h) y altas concentraciones de SPIONs (500 µg/mL versus 100 µg/mL) inducen un estrés oxidativo más severo debido a el aumento de la oxidación de lípidos. En segundo lugar, investigamos las consecuencias de la ingesta de comida sobre los gusanos después de 24 h de exposición a AuNP de 10 nm. Se identificó el papel protector de los alimentos en la reducción de efectos tóxicos. Usando SR-μFTIR, encontramos que las AuNPs de pequeño tamaño (10 nm frente a 150 nm) o la exposición prolongada (24 h frente a 4 h) causaron un mayor nivel de oxidación de lípidos que se relacionó con las respuestas contra el estrés oxidativo. Por otro lado, evaluamos preliminarmente la posibilidad de realizar la terapia fototérmica en gusanos que contenian AuNP de 150 nm. Encontramos daños por fotoablación en los puntos de irradiación láser sobre los gusanos, sugiriendo que se podría usar este gusano para evaluar NPs, pero para ello es necesario optimizar la configuración experimental. En la parte final, presentamos algunas colaboraciones donde realizamos experimentos con diferentes nanomateriales como luteína y metal-organic frameworks (MOFs), evaluados empleando C. elegans. Estudiamos las propiedades antioxidantes de la luteína en C. elegans modificados para ser modelos de enfermedades asociadas con el síndrome de Leigh y demostramos la posibilidad de aplicar microscopia de infrarrojo (SR-μFTIR) en estos estudios. Por otro lado, realizamos la evaluación preliminar de toxicidad de MOF, MIL-127 y CS-MIL-127 recubierto de quitosano (CS). Además, investigamos los efectos del recubrimiento de CS en la absorción y excreción por los C. elegans. En resumen, hemos encontrado que la disponibilidad de comida puede disminuir los efectos adversos, parcialmente asociados con el estrés oxidativo, inducidos por SPIONs o AuNPs en C. elegans. Nuestros resultados también sugieren que los C. elegans tienen un gran potencial como modelo de administración oral ya que pueden emplearse para probar diferentes materiales. Además, en combinación con otras técnicas avanzadas, nos pueden ayudar a comprender de forma más general los mecanismos de toxicidad y ampliar el rango de aplicación de las técnicas de ciencia de materiales para la investigación biológica.
During the last decades, nanoparticles (NPs) have been widely used in various fields, especially in medical applications such as drugs, imaging agents, and drug-delivery carriers. However, they also raised public concerns regarding the potential adverse influences on human health. Collective efforts from worldwide researchers in materials and biological science have been invested in investigating the toxicity mechanisms of different NPs. In this thesis, we dedicated major efforts to apply (Caenorhabditis elegans) C. elegans as a robust and simple model organism for toxicity assessments of assorted NPs. The general objective of this thesis was to study effects of food availability on nano-bio interactions between superparamagnetic iron oxide nanoparticles (SPIONs) or 10 nm AuNPs and C. elegans, and prove that this small animal can be used to study alimentary effects. Firstly, we studied the effects of food availability on toxicities induced by exposure to SPIONs after 24 h (acute exposure) or 72 h (prolonged exposure). We found that food provided some protection to C. elegans determined by measuring multiple toxicity endpoints such as survival and reproduction. Worms in the acute exposure condition had a higher uptake efficiency of SPIONS facilitated by food compared with the condition without the addition of food. The utilization of synchrotron Fourier transform infrared microspectroscopy (SR-μFTIR), allowed us to demonstrate that long-exposure (24 h versus 4 h) and high concentrations of SPIONs (500 µg/mL versus 100 µg/mL) induce more severe oxidative stress determined by increased levels of lipid oxidation. Secondly, we investigated food’s influences on worms after 24 h exposure to 10 nm AuNPs. The protective role of food was identified in reducing toxic effects, such as survival and reproduction. Using SR-μFTIR, we found that small-sized AuNPs (10 nm versus 150 nm) or long-exposure (24 h versus 4 h) caused an increased level of lipid oxidation which was related to responses against oxidative stress. On the other hand, we preliminarily evaluated the possibility of performing the photothermal therapy in worms containing 150 nm AuNPs. We found photoablated damages on the laser irradiation spots of worms, suggesting that multiple experimental settings needed to be optimized. At the end of the thesis, also we presented some collaborations where we performed some experiments with different nanomaterials such as lutein and (metal-organic frameworks) MOFs and evaluated them on C. elegans. We studied antioxidative properties of lutein in C. elegans disease models associated with Leigh Syndrome and demonstrated the possibility to apply synchrotron Fourier transform infrared microspectroscopy (SR-μFTIR) on this topic. On the other hand, we performed the preliminary toxicity assessment of MOFs, MIL-127 and chitosan (CS) coated MIL-127 (CS-MIL-127). Additionally, we investigated about effects of the chitosan (CS) coating on C. elegans’ uptake and excretion efficiencies of MIL-127 and CS-MIL-127. We reported the potential of applying C. elegans as an oral administration model of studying metal-organic frameworks’ (MOFs’) in vivo toxicities. In summary, food availability could decrease adverse effects, partially associated with oxidative stress, induce by SPIONs or AuNPs on C. elegans. It also suggested that C. elegans has a great potential of being employed as an oral administration model of testing various materials. Furthermore, combined with other advanced techniques, we could have a more general understanding of the toxicity mechanism and broaden the application range of material science techniques for biological research.
Chiewpattanakul, Paramaporn. "Isolation and structure elucidation of biosurfactant from microorganism and its application model in drug delivery system." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL004N/document.
Повний текст джерелаBiosurfactant producing microorganisms were isolated from oil contaminated soils collected from Songkhla and Chiangmai province, Thailand and Shianghai, China. Their culture broths were screened for obtaining biosurfactants with the highest surface activity and emulsification ability. Among 102 isolates, 6 microorganisms produced biosurfactants. The culture supernatant of SK80 strain exhibited the highest surface activity. SK80 was identified by macroscopic morphology, microscopic morphology and showed that it is a black mold. The 28S rRNA sequence homology analysis suggested that SK80 belongs to Exophiala dermatitidis. The composition of culture medium such as carbon source, nitrogen source, and culture condition of this microorganism was optimized to obtain high amounts of biosurfactant. 1H NMR, 13C NMR, COSY and Mass Spectrometer (APCI MS) results indicated that this biosurfactant was monoolein (oleoyl glycerol), a kind of monoacylglycerol. Monomyristin was chosen as a monoacylglycerol model to be synthesized and used as nanoparticle encapsulated drug. Two preparation methods, emulsion/solvent evaporation and nanoprecipitation, were used to encapsulate monomyristin in dextran-covered nanoparticles with poly(lactic acid) of hydrophobized dextran as the core material. Encapsulation conditions were optimized with regard to the yield encapsulation and the colloidal stability
Fernandez, Maxence. "Auto-assemblage de nanoparticules métalliques et semi-conductrices dirigé par reconnaissance entre protéines artificielles." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S129.
Повний текст джерелаNanoparticles self-assembly driven by biomolecules is a promising approach for developing nanostructured materials with new optical properties. The purpose of this work is the self-assembly of metal and semiconductor nanoparticles directed by artificial proteins called α-Repeat. For this purpose, semiconductor nanocrystals (CdSe/ZnS or CdSe/CdS) and spherical or anisotropic gold nanoparticles have been prepared. These nanoparticles have been functionalized with PEGylated peptide ligands providing them adequate colloidal stability while maintaining their optical properties. A functionalization strategy based on polycysteine and poly-histidine tags has allowed the proteins to be grafted onto the surface of inorganic nanoparticles. Nanoparticles functionalized with artificial proteins were then used for the self-assembly of semiconductor nanoparticles and hybrid self-assembly between semiconductor nanoparticles and metal nanoparticles. The structure study of self-assembled nanostructures has shown, in some cases, a very well defined sub-10 nm interparticle distance. Finally, the study of optical properties revealed very strong exciton-plasmon interactions induced by self-assembly. This self-assembling process strongly affected the emission properties of the semiconductor nanoparticles in hybrid ensembles
Tang, Lu. "Nanoparticules mimes des propriétés biologiques des GAGs : vers un inhibiteur sélectif de CXCL12." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS072.
Повний текст джерелаHéparan Sulfate (HS) is a linear polysaccharide that modulates the biological activities of numerous proteins. In order to elucidate the interaction between HS and proteins, the synthesis of HS is an invaluable tool, but the synthesis is sometimes difficult. Our group has demonstrated that the combinatorial mixtures obtained by self-assembly of different combinations of disaccharide derivatives (lactose and persulfated lactose) on gold plan surfaces could recognize specifically some HS binding proteins, such as the isoforms of the chemokine CXCL12 or IFNγ. Because of the toxicity of gold nanoparticles, we have also adapted this method to lipid nanoparticles. Using the conditions that have already improved during the synthesis of lactose and persulfated lactose derivatives, we have synthesized two other disaccharide derivatives, which were closer to the real structure of HS. These new derivatives were used to prepare the gold and lipid nanoparticles at the aim of comparing the properties with lactose and persulfated lactose. The tests of affinities with different proteins are in progress
Buchy, Eric. "Conception de bioconjugués squalénisés dotés de propriétés d'auto-assemblage : vers une méthode générale de vectorisation nanoparticulaire." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS267.
Повний текст джерелаSqualenoyl conjugates of semaxanib and sunitinib, two potent antiangiogenic (pyrrolyl)methylidenyl-substituted oxindole multitarget tyrosine kinase inhibitors, were synthesized with a hemiaminal-based pH-sensitive linker. The prodrugs were prepared according to a three-step sequence involving (i) N-alkylation with chloromethoxy-triisopropylsilane; (ii) desilylation; and (iii) acylation with trisnorsqualenic acid. These squalenoyl prodrugs were found to selfassemble into nanoassemblies in aqueous media without the need for any surfactant. The nanosized aggregates were characterized by dynamic light scattering and transmission electron microscopy, and appeared to be stable in water for several days, as determined by particle-size measurement. In vitro biological studies showed that squalenoyl sunitinib nanoassemblies are notably cytotoxic against the human umbilicalvein endothelial cell line (HUVEC), which is involved in the tumor vessel formation
Bordat, Alexandre. "Stratégies alternatives pour la délivrance d'anticancéreux par encapsulation physique dans des nanoparticules polymère thermosensibles ou par couplage chimique en prodrogues polymères." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS595.
Повний текст джерелаThis thesis focuses on innovative drug delivery systems of anticancer drugs to tackle the current limitations of formulations based on nanoparticles. These allow encapsulation of anticancer drugs to prolong their circulation time in the blood stream and to decrease side effects. Yet, nanoparticle formulations available in the clinic do not allow a precise control on the drug release nor targeting of the tumor.To overcome these hurdles, we have synthesized a thermoresponsive copolymer exhibiting an upper critical solution temperature (UCST) to formulate nanoparticles physically encapsulating doxorubicin. These allow controlled release of the anticancer drug by mild hyperthermia at 43 °C. We have studied our system from a physico-chemical point of view and evaluated its cytotoxicity in vitro on ovarian cancer cells.We have also tried a chemical coupling approach between the polymer and the anticancer drug, paclitaxel, to allow innocuous subcutaneous administration. In did, this route of administration is seldom used for anticancer drugs as some of them induce local toxicity at the site of injection in the form of skin irritation / necrosis. We assessed if a hydrophilic polymer prodrug approach allows innocuous subcutaneous administration of an irritant drug; and if a UCST polymer prodrug approach enables formation of stable nanoparticles at room temperature for subcutaneous administration. Once in the subcutaneous tissue at 34 °C, they would solubilize and become hydrophilic thus could freely diffuse to reach the blood circulation. We have managed to evaluate the hydrophilic polymer prodrug approach in vivo on nude mice and we are the first to describe the synthesis of UCST polymer prodrug
Boissenot, Tanguy. "Nanocapsules théranostiques pour l’imagerie par IRM-19F et la libération contrôlée par ultrasons." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS078.
Повний текст джерелаWe have developed theranostic nanocapsules combining a diagnostic moiety to improve tumor detection and a therapeutic moiety to treat them. These nanocapsules are composed of a polymer shell of PLGA-PEG and a core of a perfluorocarbon, namely perfluorooctyl bromide, detectable by 19F-MRI. Paclitaxel, a cytotoxic drug, was encapsulated in an attempt to reduce side-effects associated with excipients such as Cremophor® used in the commercial formulation (Taxol®). We optimized encapsulation of paclitaxel into nanocapsules by varying formulation parameters to prevent or limit paclitaxel recrystallization and nanocapsule aggregation. The optimized formulation was tested in vitro on CT-26 colon cancer cells and showed similar cytotoxicity as compared with Taxol®. Paclitaxel pharmacokinetics and biodistribution were evaluated in nude mice bearing CT-26 tumors comparing nanocapsules with Taxol®. For nanocapsules, pharmacokinetic parameters are improved leading to a longer circulation and resulting in an enhanced accumulation in tumors, as confirmed by 19F-MRI. In terms of efficacy, this enhanced passive targeting allows a slower tumor growth in animals treated with paclitaxel-loaded nanocapsules compared to PBS and Taxol®. Ultrasound were also used to further improve tumor targeting. We showed that when applying a safe ultrasound sequence, tumor growth was slower on our tumor model. In vitro studies showed that this decreased growth is due to mild hyperthermia favoring tumor perfusion and vascular extravasation leading in an enhance accumulation of drugs inside the tumor
Marchioni, Marianne. "Ecoconception de nouveaux agents biocides à base de nanoparticules d'argent à enrobage bio-inspiré." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAV046/document.
Повний текст джерелаSilver nanoparticles are increasingly used in everyday consumer goods as well as in medical devices for their biocidal activity, which is due to the release of Ag(I) ions over time. The hindsight on these nano-objects and, in particular, on their safety is still not sufficient and studies on their transformation and their impact in vivo is currently an intense research field. Indeed, the fate in the body of macro- and micro-materials studied classically is not the same as for nanomaterials. The case of the silver nanoparticles illustrates this problem: the soluble silver injected intravenously is eliminated faster than the same amount of silver injected in nanoparticular form. Moreover, the concentration of silver found in the bloodstream and organs is ten times higher when silver nanoparticles are injected rather than ingested. The development of silver nanoparticle-containing implanted devices, that get in direct contact with the body, must thus take into account the related risks. A Safer-by-design approach could be a way to solve this issue.One of the main components of Safer-by-design development is the functionalization of nano-objects. The affinity of the thiolates for Ag(I) ions is very high, which would make thiolated ligands a good tool for silver nanoparticle functionalization. However, it is known that the thiolated molecules lead to different behaviors, ranging from the dissolution of silver nanoparticles into Ag(I) ions to the simple passivation of the surface of the nanoparticles, which leads to the loss of their biocidal activity.The Ecodesign of New Biocidal Agents based on Silver Nanoparticles and Bio-inspired Coating is therefore at the interface of several research areas and its main objective was to lay the conceptual foundations for the development of a Safer-by-design biocidal agent based on the interaction between silver nanoparticles and thiolated molecules.The development of this project required to study the reactivity of various biological or bio-inspired thiolated molecules with silver nanoparticles. First of all, we have highlighted the importance of the architectural pre-organization of biomolecules in the dissolution kinetics, as well as the role of the number of free thiols in the molecule. In the case of molecules inducing the dissolution of the nanoparticles, its kinetics increases with the number of free thiols present on the molecule and with the pre-organization of the metal binding site. In a second time, the main project of this thesis was the development of a proof of concept of a new biocidal agent composed of silver nanoparticles bridged together via a thiolated ligand, which is the chemical mimic of one binding site of a metallothionein. These nanoparticle assemblies were active against bacteria (E. coli) and less toxic than silver nanoparticles on eukaryote cells (HepG2), despite a similar cellular entry. Finally, a screening was performed with polyethylene glycols having two to eight thiols and varying polymer lengths in an attempt to rationalize the differences in the behavior of silver nanoparticles in the presence of the thiolated molecules. This ongoing work leads to various behaviors that will enable to explore novel ways for the development of biocidal based on nanoparticles assemblies mediated by thiol – Ag(I) bonds.Therefore, this overall PhD work allows performing both very fundamental researches concerning the reactivity of thiols with surface silver atoms of the nanoparticles and the development of products with application potential, silver nanoparticle assemblies that are Safer-by-design biocide
Hou, Xue. "Nano-objets photo-activés pour le ciblage cellulaire et l’hyperthermie." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLC011/document.
Повний текст джерелаPlasmonic nanoparticles possessinteresting properties thanks to the localizedsurface plasmon resonance. In addition totheir high photothermal conversion efficiency,the heat release confinement can bemodulated by the type of light source used(pulsed or continuous laser). These propertiesmake the plasmonic nanoparticles a potentialsolution for cancer therapy by hyperthermia.In order to develop such a biomedicalapplication, it is necessary to optimize theabsorption of light energy and the targeting ofnanoparticles on the tumor considered.In this thesis, the influence of the photogeneratedhot electrons on the absorption ofultrashort laser pulses by nanoparticles is firststudied. Then, a work carried out withchemists, biologists and physicians for theapplication of gold nanoparticles irradiated byultrashort laser pulses to cancer therapy isdescribed. Finally, we present a preliminarystudy on the photoluminescence of plasmonicnanoparticles, the origin of which is stillcontroversial, by applying a model accountingfor the non-thermal nature of the hot electrondistribution
Le, Hong Duc. "Modelling of nanoparticles laden jet from a conveying pipe leakage." Phd thesis, Toulouse, INPT, 2018. http://oatao.univ-toulouse.fr/21454/1/LE_Hong_Duc.pdf.
Повний текст джерелаHelgadottir, Inga. "Synthèse Contrôlée de Nanoparticules de Métaux Oxophiles en Milieu Liquide lonique pour Applications en Microélectronique." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10286.
Повний текст джерелаSmall size (below 10 nm) metallic nanoparticles and metallic nanoalloys have attracted much interest in a range of applications, which require precise control of size, composition, and morphology, in chemically significant quantities. Hence, the variety of compositions and structures (size, morphology, atomic arrangement) bring a vast range of possibilities. This PhD was aimed at expanding the knowledge already obtained in this laboratory on monometallic nanoparticles. Indeed, it has been demonstrated that the decomposition of organometallic precursors in selected ionic liquids can lead to the formation of stable suspensions of metallic nanoparticles below 5 nm. In this context, a first achievement in this work has been to push this route towards more oxophilic, less approachable metals, such as tantalum. Besides, this route has been shown to generate bimetallic nanoparticles upon decomposition of mixtures of precursors, with size, structure and composition controlled, such as Ru@Cu. This PhD work has dentified the mechanism of formation of these nanoalloys, developing a versatile route that could be used to design nanoalloys to fulfill specific applications, e.g., RuNi, RuTa, CuNi, etc
Girard, Adrien. "Étude du confinement acoustique dans des nano-structures métalliques et semiconductrices par diffusion Raman basse fréquence." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1106/document.
Повний текст джерелаInelastic light scattering spectroscopies (Raman/Brillouin) are a versatile tool to study thermal phonons at various scales. In nano-granular media, the study of acoustic phonons with a wavelength much greater than the grain diameter D (?/D >> 1) allows one to characterize the macroscopic elasticity governed by Hertz law of the contact. The validity of Hertz law is studied for powders made of oxide nanoparticles a few nanometers in diameter. When the phonon half-wavelength reaches the confinement dimension (diameter D for spheres, thickness e for plates) propagation is forbidden and mechanical resonances occur. Low frequency Raman spectroscopy has been used to characterize the acoustic resonances of semiconducting nanoplatelets “dressed” with an organic surfactant layer. When the thickness becomes thin enough (e ~ 1 nm), the resonance frequency is significantly downshifted compared to a free platelet, attributed to a mass load effect due to the organic molecules. When the confining object is a metallic nano-dimer, both plasmonic and acoustic hybridization occur at the same time. The resonant excitation of the dimeric plasmon allows one to observe down to single nano-object scale the inelastic scattering by dimer hybridized dipolar vibration modes l=1 as well as non-hybridized modes with higher angular momentum l >2, known to be Raman inactive in this size range according to previously established selection rules. Possibilities for a new plasmon-vibration coupling mechanism are discussed
Millart, Elodie. "Nanoparticules lipidiques de type Janus à compartiment superparamagnétique : du procédé de mise en oeuvre aux applications théranostiques." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS540/document.
Повний текст джерелаIn recent years, our team has developed original compartmented lipid nanometer-sized particles produced by high pressure homogenization, a scalable process, with pharmaceutically approved excipients. The particles actually belong to the family of Janus nano-objects as they are organized in two juxtaposed substructures : one half is a droplet of liquid-state lipids while the other half is vesicle-like and encloses an aqueous core delimited by a phospholipid-containing bilayer shell. Added to the intrinsic biocompatibility of the constituting lipids, such a system provides a potentially very valuable tool in pharmaceutical and biomedical fields, able to separately incorporate and co-convey hydrophilic and lipophilic substances with distinct activities, for example, a medical imaging agent and a drug for coupling diagnosis and therapy. Here, we are interested in loading Janus nanoparticles with a magnetic fluid composed of superparamagnetic iron oxide nanocrystals (ferrofluid, FF), indeed as efficient contrast agent for MRI, being magnetically targetable and providing ability for hyperthermia treatment. Alternately, hydrophilic or lipophilic FF compatible with the production process have been developed by investigating different stabilization pathways of the nanocrystals depending on the encapsulation compartment
Dzumedzey, Yuliya. "Mobility of manufactured nanoparticles within a natural organic gel." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0159/document.
Повний текст джерелаThe mobility and fate of manufactured nanoparticles (NPs) in the environment drive the exposure behaviour. This study deals with the question on how NPs interact with environmental components, and how this interaction may alter the NPs fate and impact on the biota. We investigated the interaction of variably charged and sized NPs (TiO2 NPs, as analogues of those typically released from sunscreen, and Au NPs as models) with pure polysaccharide YAS34 as analogue of bacterial gels. The release of TiO2 NPs from a typical sunscreen under aqueous aging was first studied. The interaction between NPs and the bacterial polysaccharide was studied (1) in diluted suspension conditions, (2) by deposition on the gel surface as compared to a bare SiO2 mineral collector, and (3) by measuring the NPs transfer through the gel. Favorable and unfavorable conditions for NPs attachment to the polysaccharide were prepared by selecting appropriate pH and NPs coating.Under favorable conditions, the NPs tended to heteroaggregate with the EPS in suspension, leading to their partial sedimentation. On the EPS substrate, the NPs deposition was influenced by the physicochemical conditions. The NPs deposition is driven by electrostatic interactions with the collector and is also affected by the interactions between the neighbouring NPs. Surprisingly, under unfavourable conditions, some weak attractive interactions were again evidenced both in suspension and deposition experiments that we attributed to be dependent on the NP organic coating competing with the EPS.The NPs transfer through the gel was favored under repulsive electrostatic interaction, and affected by the NPs size and by the solution pH
Pisani, Cédric. "Etude toxicogénomique de nanovecteurs de silice mésoporeuse : relation entre décoration et toxicité." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTS009/document.
Повний текст джерелаNanoparticles (NPs) capable of transporting and releasing therapeutic agents to target tissues constitute one of the most exciting areas in nanomedicine, especially magnetic mesoporous silica nanoparticles (M-MSN). M-MSNs may be addressed to tumors thanks to their magnetism and can act as drug carriers thanks to their high specific surface area. Nevertheless, the safety of these NPs with decorations, conferring them specific properties, must be assessed in order to avoid harmful effects on healthy tissues, in particular on the liver, the organ of xenobiotics metabolism.The goal of this thesis was therefore to evaluate the potential toxicity of M-MSN either pristine, or coated with polyethylene glycol (PEG), or surrounded by a lipid bilayer of 1,2-dimyristoyl-sn-glycero-3- Phosphocholine (DMPC). To this end, the human hepatic cell model HepaRG was chosen to realize in vitro toxicity testing and to elucidate the intracellular mode of action of these various NPs.The physico-chemical properties of pristine and covered M-MSNs were measured using different techniques such as dynamic light scattering (DLS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). NPs toxicity was first evaluated by viability testing and real-time cell impedance analysis (xCELLigence).Gene expression profiles were then performed through very high density oligo microarrays (8x60k, Agilent) to evaluate, in a dose- and time-dependent manner, the toxicity of these NPs. In addition, the use of an original methodology for comparative analysis of large biological data allowed us to demonstrate the molecular mechanisms triggered by the NPs in the hepatocytes. We were able to determine the dose not triggering any toxicity as well as the dose inducing a slight transient toxicity after 24h. We thus defined this latter value as a threshold of biocompatibility with HepaRG cells. We also showed by TEM a slower uptake of PEGylated NPs by cells as well as their delayed effects on the transcriptome compared to the pristine and DMPC NPs. Nevertheless, a dose of 80 μg/cm² of pristine or covered M-MSNs triggers the chain of events of the hepatic cholestasis AOP (Adverse Outcome Pathway). This result demonstrates that this methodology is suitable for predictive toxicology by analysis of cellular biological responses after exposure to exogenous substances.Furthermore, NPs tend to be covered with proteins in the presence of serum (corona). Cell impedance analysis shows that M-MSNs surrounded by human or bovine serum proteins coronas do not trigger the same toxicity on human cells. This result raises the problem of a potential overestimation of NPs toxicity to human cells in in vitro testing by using fetal bovine serum in culture media.We undertook a dynamic analysis (between 30 s and 7 days) of the corona formation by tandem mass spectrometry has highlighted three groups of protein with distinct behaviors. The first cluster contains some abundant proteins that desorb over time, the second cluster comprises some protein families such as apolipoproteins, and the third cluster contains late enrichment proteins attracted by other proteins already present in the corona. A dynamic network of protein-protein interactions inside the corona, namely the interactome, was built from the data. This work opens the way to a possible control of the corona in order to provide the nanocarriers with stealth properties allowing them to reach target organs without being opsonized.These techniques used during this thesis and based on analyses of biological big data might be part of the future standards on nanosafety evaluation
Smith, Beverly. "Investigating Thermal Transformations of Ligand-Stabilized Gold Nanoparticles: Influence of the Structural Attributes of the Nanoparticle and Its Environment on Thermal Stability." Thesis, University of Oregon, 2015. http://hdl.handle.net/1794/19259.
Повний текст джерела10000-01-01
Couzon, Nelly. "Synthèse et propriétés photoélectrochimiques de nanoparticules d’argent intégrées dans des films d’oxydes mésoporeux." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1171/document.
Повний текст джерелаThe study and understanding of existing interactions between semiconductor and metal nanoparticles under irradiation is essential for improving their performance. In this study, three semiconductor-metal oxide composites were synthesized: TiO2-Ag, Fe2O3-Ag and WO3-Ag. The synthesis of the mesoporous films of TiO2, Fe2O3 and WO3 was carried out by gel sol method using block copolymers, with the method of self-assembly induced by evaporation (EISA). The silver nanoparticles are formed in a second time by chemical reduction of silver salts in the porosity of the films. The photo-electrochemical study of these composites made it possible to highlight various phenomena: the electroreduction potential of Ag+ ions in a mesoporous TiO2 matrix can be modulated by the effect of light. This phenomenon seems to result from a passivation effect of the NP Ag by TiO2, which depends on the insolation conditions. Charging effects of the porous electrode in Ag+ species have also been observed, under the simultaneous action of chrono-amperometry and irradiation
Fasquelle, François. "Etude de la délivrance d’antigènes dans les voies aériennes en utilisant des nanoparticules de maltodextrine lipidées." Thesis, Lille, 2020. https://pepite-depot.univ-lille.fr/LIBRE/EDBSL/2020/2020LILUS024.pdf.
Повний текст джерелаThe mucosal routes of immunization present several advantages compared to classical injection routes. Indeed, besides a better compliance towards patients, these routes possess their own immune system, also known as the Mucosal Associated Lymphoid Tissue (MALT), able to trigger a local mucosal response after immunization. This tissue is mainly located in the nasal and intestinal mucosa, where it is spread in small extents called Follicular Associated Epithelium (FAE). On their apical surface, the FAE contain specialized epithelial microfold cells (or M cells), whose role is to survey potential infections by sampling pathogenic fragments, and which overlay a lymphocyte and antigen presenting cells (APC) zone. Then, when an infection occurs, M cells sample and translocate antigenic fragments to CPA, which could therefore trigger lymphocyte maturation and the initiation of the subsequent immune response. This activation will lead to both humoral and cellular immunity in the infected epithelium and could also spread to distant mucosa. As many pathogens infect the body through mucosa, this way of immunization is often considered.Adjuvants are frequently added to subunit vaccines to enhance their immunogenicity toward APC. Indeed, despite their lower toxicity, they are also less immunogenic than live-attenuated vaccines. However, the administration of classical adjuvanting molecules, such as toxins or immunostimulating emulsions, via mucosal routes, has often led to serious adverse effects. Therefore, the alternative use of delivery systems to deliver antigen in APC after mucosal administration is more and more studied.Antigen delivery systems include immunomodulating particles, and inert delivery systems. The first ones can enhance the mucosal antigen bioavailability by vectorizing antigens to APC, and at the same time trigger intracellular pro-inflammatory pathways, to drive the Th1/Th2 immune balance. Among them, virus-like particles (VLP), saponin-based emulsions (ISCOMs) or MPL-containing liposomes are the most represented in clinical trials. However, their mucosal administration can lead to the same adverse effects than classical immunostimulating molecules. In parallel, true delivery systems can enhance the antigens immunogenicity by increasing their intracellular delivery, thus mimicking a natural infection. They are therefore far less toxic for the mucosa than immunomodulating particles but need to be more efficient in the mucus penetration, in the antigen association and in the APC intracellular delivery.During this thesis, we deciphered the mechanisms allowing cationic and lipidated maltodextrine nanoparticles (NPL) to deliver antigens after nasal administration.We first evaluated the ability of NPL to cross the airway mucus barrier, compared to mucopenetrant particles (PEG-coated PLGA or PLGA-PEG) and mucoadherent particles (chitosan-coated PLGA or PLGA-CS), by measuring their displacement in reconstituted mucus. We observed that in presence of the phospholipid core, the NPL were able to move in the mucus, while PLGA-CS NPs remained stuck in the gel. Moreover, we observed that the NPL uptake and the protein delivery in airway epithelial cells were not impaired by the presence of mucins, contrary to PLGA-CS that were hindered by the mucins, and to PLGA-PEG which were not taken up by the cells, due to their neutral surface charge. We finally demonstrated that the NPL mucopenetration was allowed thanks to steric and repulsive electrostatic forces between the anionic phospholipid core and the mucins.In parallel, we studied the mechanisms allowing the NPL to enhance the immunogenicity of subunit antigens after nasal administration, with a highlight on the importance of the NP’s density [...]
Paul, Emmanuel. "Nanoparticules manufacturées : translocation et impact pulmonaire d'une exposition par voie respiratoire durant la gestation dans un modèle murin." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1019.
Повний текст джерелаEXPOSURE TO MANUFACTURED NANOPARTICLES DURING GESTATION: IMPACT ON THE RESPIRATORY TRACT OF THE OFFSPRINGDue to several commercial applications of nanoparticles (NPs), such as silver (Ag), titanium dioxide (TiO2) and cerium dioxide (CeO2), knowledge of the toxicity of those NPs is of great importance. It has been shown that exposure to NPs may lead to an inflammatory response and pulmonary fibrosis. However less is known on the effect of exposure to NPs on the offspring. Therefore the aim of this study is to assess the impact of exposure by the respiratory route to various NPs during pregnancy on lung development of the offspring, and to determine the key parameters involved in lung alterations. We used three NPs: TiO2, Ag, and CeO2, to assess the impact of NPs physico-chemical properties on the potential effects on lung development. Pregnant mice were exposed weekly to 100 μg NPs or saline by nonsurgical intratracheal instillation. Analysis of the lungs of the offspring was performed at different times of lung development, before (17.5 gestational day) and after birth (14.5 and 49.5 post-delivery day). Results showed that after pulmonary exposure during pregnancy, all nanoparticles induced a long-lasting impairment of lung development of the offspring. This was accompanied by a decreased placental efficiency which was associated with the presence of NP in placenta and a decreased pulmonary expression of VEGF-alpha and MMP-9 at the fetal stage, and FGF-18 at the alveolization stage. In view of the growing use of these nanoparticles, this result raise concerns for public health and pregnant women and their developing fetus particularly for those at high risk of occupational or domestic exposure.Keywords: nanoparticles, pregnancy, lung development
Lavie, Julien. "Synthesis and properties of graphene quantum dots and nanomeshes." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS370/document.
Повний текст джерелаThe manipulation of the electronic properties of graphene, and in particular the bandgap opening by nano-patterning, is a crucial issue for both physics and applications. The nanostructuration can be done either through the top-down approach or the bottom-up approach. This bottom-up approach allows controlling at the atomic level the structure of the materials. The aim of this thesis is to prepare graphene quantum dots and graphene nanomeshes (regular arrays of holes in a graphene sheet) by chemical synthesis, and to study their physical properties. In the first part, a “family” of graphene quantum dots was prepared with organic chemistry via Diels-Alder and Scholl reactions and the optical properties were studied both in solution and at the single molecule scale. In the second part, a new type of graphenic structures intermediate between quantum dots and nanoribbons were synthesized and we named them “graphene nanorods”. These objects are one dimensional but have a controlled length compared to nanoribbons prepared via polymerization. Finally, various precursors were synthesized to create graphene nanomeshes. These precursors will allow the formation, using chemical vapor deposition in a scanning tunneling microscope chamber, of nanomeshes exhibiting different structures and morphology
Albert, Claire. "Émulsions de Pickering biodégradables stabilisées par des nanoparticules de poly(acide lactique-co-glycolique) : étude physico-chimique et potentialité pharmaceutique." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS491.
Повний текст джерелаIn this thesis work, we formulated stable, biodegradable and biocompatible Pickering emulsions stabilized with nanoparticles (NPs) of poly(lactic-co-glycolic acid) (PLGA). Such emulsions are an alternative, potentially less toxic and irritating, to conventional emulsions stabilized with surfactants. Firstly, a thorough physico-chemical study of these systems was conducted in order to clarify their structures (macroscopic, microscopic and interfacial) as well as their mechanisms and kinetics of stabilization. Studies of the contribution of the polymer stabilizing the NPs and of the characteristics of the PLGA polymer on the properties of the emulsions were also carried out. This enabled a better identification of the physico-chemical key parameters responsible for a good stabilization. Secondly, we focused on the pharmaceutical potential of these emulsions for a topical application. Pharmaceutical active ingredients (API), used for the treatment of psoriasis, were successfully encapsulated in the NPs (cyclosporine A and tacrolimus) and the emulsion droplets (calcitriol). This study is a first step towards the use of these emulsions for the co-encapsulation of two API: one in the NPs and a second in the oil droplets. The co-encapsulation should improve patient compliance and could lead to a synergistic effect between the two API
Yu, Qian. "Transport électronique dans les nanoparticules : du réseau à la nanoparticule individuelle." Paris 6, 2013. http://www.theses.fr/2013PA066747.
Повний текст джерелаI present a study of electron transport in arrays of gold nanoparticles formed by the Langmuir –Blodgett method. In weakly coupled arrays, electronic transport is due to sequential tunnel diffusion described by activated laws. By increasing the coupling between the nanoparticles, a diffusion regime controlled by cotunneling is reached, where electronic transport is described by the Efros-Shklovskii law. The nanoparticles, which present various electronic properties, allow considering the study of their electronic spectrum in the regime of strong quantum confinement. To study the electronic spectrum of individual nanoparticles, we developed a setup for vacuum projection of nanoparticles which allows fabricating efficiently single nanoparticle devices. This setup has been tested with the observation of Coulomb blockade in gold nanoparticles. Then, this setup has been applied to the fabrication of single nanoparticle devices with magnetite nanoparticles. These circuits allowed establishing the out-of-equilibrium phase diagram of the Verwey transition as function of temperature and electric field. We have also studied the evolution of the tunneling current in the field emission regime through thin films of PMMA deposited on two electrodes separated by a distance of the order of ten nanometers. We observed that the scission of polymer chains leads to a measurable additional electronic noise
Lin, Jiashu. "La formation et le transport des particules dans le plasma froid." Thesis, Orléans, 2020. http://www.theses.fr/2020ORLE3029.
Повний текст джерелаThis thesis studies the dust particles in plasmas. It consists of two parts. The first part is the formation of dust particles, that is to study how the dust particles are generated from the reactive gas in the plasmas. The second part is the transport behaviour of dust particles, that is to study how the dust particles act in the plasmas.In the part of the formation of dust particles, carbon dust particles are generated in the plasmas. It is known that the formation process of dust particles in plasmas can be determined by 3 steps: nucleation, agglomeration and surface grow. The nucleation step is focused. The results of experiments show that the nucleation process occurs faster in higher power, higher pressure and lower temperature. The dependency of the nucleation time on the temperature is explained by the vibration-transition energy relaxation mechanism, and that on the RF power and pressure is explained by the ratio of the charge and diffusion time of the small dust particles.In the part of the transport behaviours of dust particles, industrially fabricated particles with determined size are injected into Ar plasmas. The particles in the plasmas are observed by laser scattering with a CCD camera. The diagnostics of plasma are performed by a double langmuir probe. Pulse-time modulation to the Ar RF plasmas is studied to be a factor to influence and to control the transport of dust particles. Particles of mono-dispersed size are firstly studied in the plasmas. It is shown that the levitating positions and falling down processes can be controlled by the RF power and pulse-time modulation. Secondly, two sizes particles are injected into the plasma at same time. The different transport behaviours, as like the segmentation of levitation and different timing of falling down basis on their size, are observed. Particles of mixture sizes can be separated one size particles from other sizes. The mechanisms of transport behaviours of the dust particles are investigated by the combination of the diagnostic of plasma parameters (electron temperature and ion density in principle) by the double langmuir probe and calculation of the forces acting on the dust particles. Calculation methods adjusting to the specific experiment setup are established. The calculation results have a good agreement with that of the experiments
Mauriello, Jimenez Chiara. "Nanoparticules à visées théranostiques pour le traitement du cancer par thérapie photodynamique à un ou deux photons." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT100/document.
Повний текст джерелаNowadays, the increase of the number of low-size cancers in the world has prompted the development of novel multifunctional nanomaterials applied to new non-invasive therapies. These new therapies are expected to selectively eradicate the tumor, decreasing or suppressing the side effects induced in healthy tissues by current treatments. This study describes the elaboration of nanomaterials for the diagnostic and the therapy of low size cancers through a novel therapy: photodynamic therapy (PDT). This new technique involves the activation of a photosensitizer molecule (PS) with specific wavelengths of light giving rise to energy transfer cascades that yield cytotoxic reactive oxygen species leading to apoptotic and necrotic cell death.First, the elaboration of mesoporous silica nanoparticles (MSN) containing a porphyrin photosensitizer are presented for the treatment in vitro of prostate cancer and retinoblastoma through one-photon therapy. Functionalized nanoparticles with new ligands were synthesized to target the nanoparticles to prostate cancer cells. The decrease of the nanoparticle size to 20 nm was elaborated to cross the blood-retinal barrier and treat retinoblastomas.On the other hand, two new types of nanomaterials were designed for two-photon nanomedicine which leads to a deeper penetration in tissues. Bridged silsesquioxane (BS) and periodic mesoporous organosilica (PMOs) nanoparticles were designed from different types of tetra or octasilylated-photosensitizers and bis-organoalkoxysilanes such as ethane, ethylene or disulphide. Pure PS bridged silsesquioxane nanoparticles lead to efficient two-photon imaging and photodynamic therapy which were demonstrated in vitro. Disulfide-based BS nanoparticles were designed as biodegradable nanomaterials.Finally, in addition to the imaging and therapy, PMOs nanoparticles were tested in vitro as nanocarriers for drug delivery due to their mesoporosity. Gemcitabine or doxorubicin were encapsulated into the pores leading to high drug loadings. Beside the classical photosensitizers, nanodiamonds core-shells PMOs were tested as PDT agent. In addition, pure porphyrin nanoPMOs are presented for gene delivery in vitro and in vivo in a zebrafish model
Theodorou, Ioanna. "Evaluation of nanoparticles and aptamers for in vivo tumor targeting using optical imaging." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS247/document.
Повний текст джерелаDuring this PhD project, optical imaging was used to study the biodistribution of different types of nanoparticles for passive tumor targeting and several candidate aptamers selected by in vivo SELEX for active tumor targeting, in animal models of cancer. For the part of passive tumor targeting, the effect of zwitterionic coating on the biodistribution of polydiacetylenic micelles was investigated. Planar fluorescence imaging demonstrated passive tumor targeting during 24 h but the micelles were not retained over time as opposed to PEGylated micelles. The biodistribution of two new types of nanogels and their constituent polymers was also evaluated. Planar imaging showed passive tumor targeting 24 h for the two nanogels. Surprisingly, tumor targeting was also observed for one of the polymers, while the other was not retained.For the part of active tumor targeting, only few sequences displayed potentials for active tumor targeting. However, further investigation of these promising sequences is needed in order to validate their favorable tumor uptake.Moreover, linear correlation was observed between in vivo and ex vivo planar imaging, demonstrating the utility of optical imaging to provide basic preclinical information regarding biodistribution of nanoparticles and aptamers.In conclusion, the work done during this thesis should help open new perspectives to the development of multimodal nano-objects that can be used for applications for tumor diagnosis and even drug delivery to sites of disease
Boisselier, Julie. "Mise en œuvre d’un système de confinement et de délivrance moléculaire pour la production in situ de glucose au sein d’un hydrogel conçu pour l'ingénierie tissulaire." Thesis, Cergy-Pontoise, 2016. http://www.theses.fr/2016CERG0830/document.
Повний текст джерелаIn tissue engineering, the in vivo survival of stem cells located within a biomaterial is limited by an ischemic environment characterized by a low supply of oxygen and nutrients. Recent studies on fibrin based hydrogels (designed to improve stem cells survival after implantation) have highlighted the need to control the spatiotemporal availability of glucose within a biomaterial scaffold. Glucose release occurs through the degradation of starch, a glucose polymer, at a rate controlled by the action of the enzyme amyloglucosidase (AMG), a specific catalyst for the hydrolysis of starch.In order to eventually be of clinical impact, critical parameters must be tuned, such as the AMG leakage outside the hydrogel and its loss of activity over time. In this context, AMG encapsulation within nanoparticles of a biodegradable and biocompatible polymer, here poly(lactic-co-glycolic acid) (PLGA), is a promising means toward controlling the above parameters.The AMG-containing core-shell type nanoparticles (NPe) were synthesized by an adaptation of the double emulsion technique (water-oil-water). Different methods have been developed to determine the physicochemical and biochemical properties of the resulting nanoparticles. The synthesis was optimized to produce sterile and reproducible nanoparticles appropriate for in vivo implantable hydrogels.Nanoparticle stability and glucose release were investigated in solution and in hydrogels. A key specification of the hydrogel system, enriched in starch and NPe, is the continuous supply of glucose over 1 month. Glucose production was observed to meet this specification, highlighting the potential advantages of this approach
Morcos, Bishoy. "Mise au point d’un procédé de synthèse de nanoparticules métalliques magnétiques utilisant des liquides ioniques." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1168/document.
Повний текст джерелаMetallic nanoparticles (NPs) exhibit unique physical and chemical properties. However, their use is conditioned by the ability to control their size and structure. The decomposition of organometallic (OM) precursors under H2 is efficient to generate metallic NPs in organic solvents, but also in ionic liquids (ILs). We have shown that in the latter media, the size can be finely tuned without adding stabilizing agents. Moreover, the resulting “naked” metallic NPs are suitable for catalysis or further reaction with a second OM precursor to form bimetallic NPs.In this work, we applied this knowledge to the synthesis of mono- and bimetallic NPs in imidazolium-based ILs C1CaImNTf2. CoNPs with a diameter of ca. 4 nm were successfully synthesized by decomposition of [Co(?3-C8H13)(?4-C8H12)] under H2. Structural analysis and magnetic characterizations demonstrated that these NPs are metallic and, as expected for this size, superparamagnetic. This approach was extended to the synthesis of bimetallic CoPt and CoRu NPs. It turned out that the best strategy is probably to simultaneously decompose the Co and Pt (or Ru) precursors. This reaction provides monodisperse suspensions of NPs, a good indication that they are bimetallic. Further structural characterizations, in particular using anomalous SAXS, are also considered to elucidate their structure
Deraedt, Christophe. "Nanoréacteurs pour la catalyse en milieux aqueux." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0430/document.
Повний текст джерелаThis thesis concerns the synthesis by “click” CuAAC reactions of newnanomaterials that have various applications, in particular in catalysis. Thesemacromolecules are dendrimers, supported dendrimers and polymers that contain1,2,3-triazole rings and were used in the stabilization of essentially palladiumnanoparticles (PdNPs). These PdNPs are extremely active in the catalysis in greensolvents of C-C coupling, reduction of 4-nitrophenol and selective oxidation ofalcohols. The use of these nanoparticle catalysts at the ppm level shows theirefficiency and their ecological aspect. The integration of biferrocene units in thepolymers allowed expanding their applications to electrochemical sensors, reductantsof metallic ions to nanoparticles, polyelectrolytes, polyelectrochromic, and mixedvalentcomplexes. The impregnation of PdNPs stabilized by dendrimers on magneticsupport led to the increase of the catalyst robustness and recyclability using amagnet
Law, Frédéric. "Effet de la combinaison des nanoparticules de gadolinium et de la radiothérapie sur l'élimination des cellules tumorales." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS138.
Повний текст джерелаThe nanotechnology aims to help in the cancer treatment. Olivier Tillement and his colleagues have demonstrated that the Gadolinium-Based Nanoparticle (GdBN) can improve Magnetic Resonance Imaging (MRI) and increase radiotherapy effects. Pre-clinical studies show that the combination of GdBN with ionizing radiation is associated with tumor regression. However, the molecular and cellular processes involved this biological effect remain to be elucidated. Our results show that the combination of GdBN with IR generates oxidative stress through NADPH oxidase-dependent mechanisms, leads to cellular senescence and induces the cannibalistic activity of irradiated cells. Altogether, these results reveal that the combination of GdBN with IR promotes the killing of irradiated cells through the induction of cellular senescence and cellular cannibalism
Pantidos, Nikolaos. "Biological synthesis of stable copper nanoparticles." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29532.
Повний текст джерелаZhou, Bo. "Synthesis and characterization of crystalline assembly of poly Nisopropylacry-lamide)-co-acrylic acid nanoparticles." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4671/.
Повний текст джерелаXu, Jiang. "Contribution à la fabrication de nanoparticules en utilisant des techniques microfluidiques et applications à la libération d'actifs." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0122/document.
Повний текст джерелаPolymeric nanoparticle (NP) drug carriers present a promising technology for controlled releasesince they are capable of improving the encapsulation efficiency and stability of the drugs inside theNPs and also able to provide effective drug levels over a longer period of time, compared totraditional therapy. However, before the NP drug delivery technology becomes a reality, importantparameters of NPs like size, drug loading ability and sustained release kinetics must be wellinvestigated and optimized in order to minimize the adverse effects of chemotherapeutic compoundsand prolong the drug releasing profile in a controlled manner.In order to accomplish this objective, this thesis proposed two novel methods for synthesis of NPs asdrug delivery carriers, with assistance from bulk and microfluidic technologies, for hydrophobic andhydrophilic drugs, individually.Encapsulation efficiency as high as 80% is reached with a mass loading of 20%. We extend ourapproaches to the encapsulation of iron oxide
Gavrilov-Isaac, Véronica. "Synthèse de nanoparticules magnétiques à énergie d'anisotropie modulable." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066439/document.
Повний текст джерелаMagnetic nanoparticles with spinel structure MFe2O4 (M = Fe, Co, Mn, Zn, Ni...) have been extensively studied for their various applications ranging from magnetic recording to biomeical applications(...)
Quievryn, Caroline. "Incorporation de nano particules d'oxyde de terre rare dans un polymère commercial sous forme filamentaire." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20206.
Повний текст джерелаThis thesis focuses on the main theme of the incorporation of nanoparticles of rare earth oxide (Erbium and Praseodymium) in a commercial polymer, PVC, shaped as filaments. These fibers are made using a apparatus developped in the laboratory. The spinning method used is a wet solvent spinning process. Embedded nanoparticles are first commercial particles (Er203) but they show disadvantages, which leads to a study of synthesis of oxide nanoparticles Erbium and Praseodymium in the laboratory. This study bings to a production a laboratory pilot (KiloLab) in order to obtain 3Kg of nanoparticles composed with 60 wt% of Erbium oxide and 40 wt% of Praseodymium xide. Once these particles obtained, it have been dispersed in a solution of PVC/solvent. This "loaded" solution of nanoparticles is presses through a spinneret for the shaping. The filaments are spun in a coagulation bath in order to remove the solvent from the solution and obtain the PVC filaments (mono or multi) containing the nanoparticles of Erbium or Praseodymium oxide.A second theme is also studied in this thesis, the realization of oxicarbide boron and silicon fibers (SiBOC). This study focuses on the synthesis and conditions to obtain a poly(borosiloxane) polymer. This polymer is obtained by the synthesis of the dimetyldiethoxysilane (DMDES), méthyltriethoxysilane (MTES) and the boric acid which bring the hetero atom of boron in the final ceramic. Once the sol of borosiloxane obtained, it is semi-hydrolysed until obtention af a gel that can be spun by extrusion at ambiant temperature. The filament are wrapped around a graphite bobbin. The shaped polymer is then leaved in a stove at 60°C for a week allowing to complete the hydrolysis.Once the hydrolysis complete and the polymer fully hydrolyses, the fibers are pyrolysed under argon at high temperature to transform the fiber into ceramic fibers of SiBOC
Resano-Garcia, Amandine. "Élaboration par ablation laser en milieu liquide de nanoparticules métalliques : caractérisation et modélisation des réponses plasmoniques des nanoparticules d’or et d’argent." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0320/document.
Повний текст джерелаMetal nanoparticles (NPs) exhibit unique optical properties (OP) coming from the collective oscillations of their electrons. This effect is translated by the emergence of a band of plasmon, the characteristics which can be modulated by the size, the shape and the nature of the NPs as well as by the environment of the host. There are many methods for the preparation of NPs, and one of them is the pulsed-laser ablation in liquid (PLAL). This technique offers some advantages such as simplicity, versatility and surface NP without contamination (reducing agent residues and/or stabilizers). Its main drawbacks are the lacks of productivity and control of the NP size and shape. This work is devoted to elaboration of Ag NPs by PLAL and theoretical investigation of their OP. We give here the results about the optimization of elaboration parameters leading to obtaining reproducible and controlled distributions of Ag NPs. The OP of these NPs are measured and compared to specific physical models based on the effective medium theory (EMT). Classical EMT such as Maxwell Garnett approximation allows describing the OP of monodisperse NPs. However, conventional preparation routes unavoidably conduct to NPs showing a shape and a size distribution which induces drastic changes in the OP. A SDEMT model which considers the shape dispersion is proposed for the calculation of the effective dielectric function and absorption coefficient of colloidal solution of metal NPs in water. Contrary to the conventional theory, this model gives a better description of the measured absorption and ellispometry spectra of sample containing Ag and Au NPs
Louie, Stacey Marie. "Characterization and Modeling of Macromolecules on Nanoparticles and Their Effects on Nanoparticle Aggregation." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/396.
Повний текст джерелаMarichal, Laurent. "Interactions protéines-nanoparticules : émergence de nouveaux facteurs déterminant la formation de la couronne de protéines." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS100/document.
Повний текст джерелаNanoparticles are ubiquitous in our environment and their presence inside our bodies is now established. Besides, in a biological medium, nanoparticles are spontaneously covered by proteins that form the so-called protein corona. Depending on the corona composition, a nanoparticle will possess a specific "biological identity" conditioning its biodistribution as well as its potential toxicity.Despite being highly studied, many aspects of the protein adsorption mechanisms remain unknown. Here we particularly focused on the influence of two physicochemical characteristics, which had rarely been addressed: protein size and post-translational modifications. Also, because of their intensive use, we worked on silica nanoparticles (SiNPs).We studied the adsorption of hemoproteins on SiNPs, both of them having different sizes. Adsorption isotherms and calorimetry studies showed a relationship between the protein size and its affinity towards silica surfaces. Finer differences could also be observed by varying the SiNPs size. Additionally, structural analyses of adsorbed proteins were performed using circular dichroism and small-angle neutron scattering. The adsorption of hemoproteins, which are well-structured proteins, seems to have little effects on their structure. However, even though the quaternary structure is maintained, structural modifications can be seen.Using yeast protein extracts and synthetic peptides, the major role of arginine asymmetric dimethylation on proteins/SiNPs interaction could be established. The use of experimental and simulation techniques allowed us to understand the mechanism responsible for the high affinity of peptides having this peculiar methylation. As a whole, this work suggests that post-translational modifications can influence considerably the interactions between biomolecules and mineral surfaces
El, Hamoui Omar. "Caractérisation et développement d'une matrice d'hydrogel supramoléculaire pour la culture cellualire 3D : vers un bio-indicateur de l'effet de nanoparticules manufacturées." Thesis, Pau, 2021. http://www.theses.fr/2021PAUU3064.
Повний текст джерелаThe project of this thesis involves the development of alternative methods to conventional cell cultures called two-dimensional (2D), which are limited in terms of representativeness of the native cell behavior, and to animal models which are facing socio-scientific issues leading to reduce their use. The present work focuses on a series of studies implying the application of a new matrix based on supramolecular hydrogels for three-dimensional (3D) cell cultures. The consortium of researchers involved in this project is interested in supramolecular gelling agents based on nucleic acid chemistry. In a first step, some potential molecules have been studied at the fundamental level in order to deepen our understanding of the thermodynamic and kinetic mechanisms underlying the supramolecular gelation process.The candidate matrices were then characterized in order to obtain a biocompatible support with optimal physico-chemical properties, particularly in response to the specificities of the 3D culture of glioblastoma cells. In parallel to this study, the cell model was refined in order to improve the reproducibility of the results by developing a cell sorting method, allowing the selection of a homogeneous subpopulation of stem cells among the total population of cancer cells studied.Once validated, this new 3D cell culture method was used to study the effects of manufactured silver nanoparticles. In this perspective, it is necessary to be able to link the characteristics of the nanoparticles to their impact on the tumor spheroid. The strategy to address this issue is divided into several steps: 1) determination of the state of the nanoparticles in the culture medium; 2) study of the diffusion of the nanoparticles within the culture matrix; 3) implementation of methods to monitor the evolution of the biological system in the presence of nanoparticles.This multidisciplinary work in the fields of supramolecular chemistry, cell culture and analytical chemistry was carried out within a consortium of partners from the universities of Bordeaux, Limoges and Pau. They open the way to further studies on the effect of these nanoparticles through a new bio-indicator
Narayanan, Radha. "Shape-Dependent Nanocatalysis and the Effect of Catalysis on the Shape and Size of Colloidal Metal Nanoparticles." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6878.
Повний текст джерелаZhao, Pengxiang. "Nanoparticules d’ or : fonctionnalisations et applications en nanomédecine et nanomatériaux." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14556/document.
Повний текст джерелаThe thesis concerns functionalizations and applications of gold nanoparticles (AuNPs). In the aspects of functionalization of AuNPs, we concentrated on efficiently functionalized AuNPs by “Click” chemistry. In the aspects of applications, the PEG capped AuNPs was prepared to encapsulate vitamins, which has a potential use in hydrophobic part of human body; the folate functionalized AuNPs was used for docetaxel delivery for cancer therapy; the novel synthesis of triazole stabilized AuNPs used for biosensors; and the citrate capped AuNPs introduced into the silica thin films to check the SERS effect and spin crossover of iron complexes
Bonnemay, Louise. "Utilisation de nanoparticules magnétiques pour perturber la localisation spatiotemporelle de protéines de signalisation." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066528/document.
Повний текст джерелаAn increasing number of studies highlight the importance of signaling localization. We developed methods to perturb this localization using magnetic nanoparticles. Proteins of interest are grafted on magnetic nanoparticles, allowing to magnetically localize them. We first propose a new method to engineer directly a spatial gradient of signaling protein concentration within in cell extract droplets using super-paramagnetic nanoparticles. We observed a link between a spatial asymmetry in biochemical cues and microtubules aster positional information. Our assay provides a bottom-up approach to examine the minimum ingredients generating polarization and symmetry breaking within cells. We then examined the possibility to magnetically perturb endosomes position in HeLa cell. We found the experimental conditions to achieve this goal. Finally, we used directly cytoskeleton elements as actin filament to trigger asymmetrically confined signaling proteins and trigger microtubule assembly, in cell extract droplets. More generally, these results show how symmetry breaking within cells can be induced and studied using magnetic nanoparticles and biophysical tools
Ballot, Noémie. "Matériaux nanométriques à base de métaux 3d (Fe, Co, Ni) : Nouvelles voies de synthèse et caractérisations." Thesis, Paris 13, 2014. http://www.theses.fr/2014PA132065/document.
Повний текст джерелаThe growing interest in nanomaterials based on 3d transition metals such as cobalt, iron and nickel finds its origin in the intrinsic properties of these elements (high magnetization of iron and high magnetocristalline constant of cobalt) combined with particular property due to nanometric size and anisotropy of these alloys. Among the numerous synthetic routes, the polyol method which belongs to the chimie douce routes allows the elaboration of several finely divided inorganic materials (oxides, hydroxides, metals) by means of reduction or forced hydrolysis reactions conducted in polyol medium. The main first contribution of this work was to take advantage of these finely divided oxides and hydroxides elaborated in polyol medium to obtain metals and alloys, through a controlled reduction in solid form under hydrogen flow. Ferromagnetic particles of CoFe2, CoFe, NiFe, Ni3Fe and Fe with a blocking temperature above 300 K were obtained. The second main contribution of this work relates elaboration of anisotropic objects. Further, a new approach is proposed: forced hydrolysis in polyol medium assisted by applying a magnetic field. This type of synthesis leads to akaganeite β7&eOOH nanowires and spinel oxides nanoparticles. A relative mild reduction (300 °C) of akaganeite nanowires allows to obtain spinels phase with same morphology and magnetic properties in agreement with the chemical composition and the particles nanoscale (superparamagnetic behavior with blocking temperaturenear 300 K, high Ms and Hc dependent on the nature of the M element in the spinel MFe2O4, high in the case of cobalt and low for nickel and iron)
Casterou, Gérald. "Conception de nouveaux agents de contraste à base d'assemblage de nanoparticules d'oxyde de fer pour l'imagerie par résonance magnétique." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S055/document.
Повний текст джерелаThe magnetic resonance imaging (MRI) is widely used in the medical field for soft tissue imaging. In order to obtain images of better quality, hospitals equip themselves with MRI of higher fields. Iron-based nanoparticle contrast agents are very promising for imaging at high field. Indeed, unlike the gadolinium contrast agents, they do not lose their effeciency at high field. Several parameters must be taken into account to achieve more effective contrast agents in MRI: first, the magnetic properties of iron oxide nanoparticles. They must have significant magnetization. Then, aggregated nanoparticles are more effective than individual nanoparticles. Finally, the presence of a more or less hydrophylic layer and its thickness will influence the effeciencys of the contrast agent.This thesis presents the design of new contrast agents based on iron oxide nanoparticles assembly, since the optimization of the synthesis to obtain nanoparticles with the most interesting magnetic properties for MRI up assembly of nanoparticles to improve their effectiveness in MRI.The first part of this work is devoted to the synthesis of iron oxide nanoparticles. An organometallic approach was chosen because it allows to obtain nanoparticles of controlled size. We show in this part of the synthesis conditions have a great influence on the crystal structure of the synthesized nanoparticles and their magnetic properties.The second part of this work is dedicated to the production of controlled size aggregates of nanoparticles. The aggregation of nanoparticles is performed by solvophobic effect by adding water to a solution of hydrophobic nanoparticles in THF. We show in this section that the kinetics of aggregation depends on the amount of water added. The aggregates are then stabilized by the addition of a polymer and show that the morphology and size of the aggregates after transfer into the water depend on the molecular weight and nature of the polymer used.The third part of this work is devoted to the evaluation of the efficiency of nanoparticle aggregates as a contrast agent. The aggregates tested have shown promise, and efficiencies higher than commercial contrast agents were obtained
Ddungu, John. "Synthesis and characterisation of silicon-based nanoparticles for diagnostic applications." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF063.
Повний текст джерелаWithin the work of this thesis, entitled “Synthesis and characterisation of silicon based nanoparticles for diagnostic applications”, we have designed nanobrobes based on systems of small (< 5 nm) silicon-based nanoparticles (Si NPs) bearing different functional molecules on the surface. Si NPs were synthesised, thoroughlycharacterised and functionalised for use in in vivo imaging and electrochemiluminescence (ECL) applications. For imaging, a positron emission tomography (PET) active probe and an emissive dye have been used to show the effective imaging capabilities and fast clearance of the Si NPs from the bodies of mice.Attachment of a sugar to the Si NPs has been used to study passage through the blood-brain-barrier (BBB). Finally, attachment of ruthenium and iridium complexes has shown that the Si NPs possess some good efficiency as probes in ECL applications
Sobot, Dunja. "Nanoparticules squalenisées et lipoprotéines plasmatiques : caractérisation des interactions moléculaires et évaluation de leur implication dans la réponse thérapeutique." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS419/document.
Повний текст джерелаThe in vivo fate of intravenously injected nanoparticles is strongly affected by their interactions with the blood components. Several studies have focused on the identification of proteins adsorbed at the surface of nanoparticles whereas less attention has been devoted to the interaction with lipoproteins (LPs). Interestingly, LPs have been previously described as excellent carriers for delivery of anticancer drugs due to their particularly high receptor-mediated uptake on several cancer cell lines. In this PhD project, we focused on a bioconjugate obtained by covalent linkage of the anticancer drug gemcitabine (Gem) to squalene (SQ) (a natural lipid and precursor of the cholesterol’s biosynthesis) whose ability to spontaneously self-assemble in the form of nanoparticles has been previously described in our laboratory. We have demonstrated that this conjugation enables the spontaneous capture and transport of the SQGem by circulating lipoproteins. In vitro and in vivo experiments revealed a preeminent affinity of SQGem towards cholesterol-rich LP particles and in silico simulations further displayed their incorporation into the hydrophobic core of LPs. Such spontaneous interaction allowed for indirect targeting of cancer cells with high expression of LP receptors, which was confirmed both in vitro and in vivo in an experimental tumor model in mice. To the best of our knowledge, the use of squalene to induce drug insertion into LPs for indirect cancer cell targeting is a novel concept in drug delivery. It represents a flexible, highly versatile platform that would enable efficient drug delivery by simply exploiting endogenous lipoproteins without the need for complex nanoparticles surface functionalization or artificial lipoproteins production
Malli, Sophia. "Formulations multifonctionnelles pour le traitement des infections parasitaires cutanéo-muqueuses." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS043.
Повний текст джерелаThis project aims at developing new therapeutic strategies against parasitic muco-cutaneous infections such as urogenital trichomonosis and cutaneous leishmaniasis which still represents a major health problem worldwide.Unfortunately, metronidazole (MTZ) is a first-line systemic treatment for urogenital trichomoniasis that causes resistance and side effects. We have thus developed new strategies by acting on both the pharmacological and the physical mechanisms of Trichomonas vaginalis infection. After a successfull increase of the apparent solubility of MTZ in water using a methylated -cyclodextrin, we formulated it in a thermosensitive and mucoadhesive hydrogel composed of pluronic® F127 and a cationic and mucoadhesive biopolymer, chitosan. This formulation is specifically adapted for topical application providing a control of MTZ release and reduction of its systemic passage through the vaginal mucosa.Then, the ability of the high viscosity hydrogel to immobilize T. vaginalis was investigated by video-microscopy. Monitoring the trajectories of each parasite by multiple particle tracking showed the ability of the hydrogel alone or in combination with chitosan to completely immobilize T. vaginalis and to inhibit parasite attachment to the mucosa. These evaluations were performed on mice experimental model. However, chitosan alone did not allow parasite immobilization and did not show any anti-T. vaginalis activity. In this context, we were inspired by previous works conducted by our team on the development of formulations based on chitosan, and more particularly nanoparticles (NPs) composed of poly(isobutylcyanoacrylates) coated with chitosan. These NPs have their own trichomonacidal activity, even without adding active substances, while NPs without chitosan were inactive. Investigated of the mechanism of the activity showed better internalization of NPs when coated with chitosan. These NPs caused drastic morphological alterations on the parasite membrane. This activity could be due to the electrostatic interaction between negatively charged T. vaginalis surface and cationic chitosan coated NPs.In order to broaden the applications of these NPs to other parasites, we were interested in evaluating the anti-L. major activity of NPs coated or not with chitosan. Indeed, chitosan known for its healing properties could be particularly adapted for this pathology. We thus showed in vitro and in vivo that NPs coated with chitosan had intrinsic anti-L. major activity without adding any drug. In a second step, we decided to design chitosan elongated particles and to evaluate their anti-leishmanial activity. These particles called "platelets" are composed of chitosan hydrophobically-modified with oleic acid and cyclodextrin in water. This strategy could be interesting to improve the interaction of platelets with the L. major membrane, as these parasites had also non-spherical morphology. The histological and immunohistochemical results of skin lesions showed a significant decrease in inflammatory granuloma and a reduction in parasitic load compared with amphotericin B alone, used as a reference.In conclusion, during this thesis, several formulations were developed and showed biological activities by acting on pharmacological and/or physical mechanisms of the parasites