Dissertations / Theses on the topic 'Tensioactifs à base de PEG'
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Lu, Yaowei. "Multicompartmental lipid-based Janus nanoparticles : influence of different amphiphilic starting materials on their formation mechanisms and their suitability as drug delivery vehicles." Electronic Thesis or Diss., université Paris-Saclay, 2025. http://www.theses.fr/2025UPASQ009.
Full textThe innovative asymmetric lipid-based Janus nanoparticles (JNPs) developed by the Galien Institute can function as novel drug delivery vehicles or diagnostic agent carriers in the field of nanotechnology. To obtain this type of anisotropic particles, different raw materials (phospholipids and short-PEG-based surfactants or amphiphilic cyclodextrin derivatives) and preparation methods (hot high-pressure homogenization or nanoprecipitation) were compared. After that, we tried to optimize these JNPs in terms of knowledge of phospholipid effects and aqueous phase composition. Especially, the relationship between JNP morphology and phospholipid properties was established by considering the packing parameter of phospholipids. By investigating the interaction between phospholipids and short-PEG-based surfactants that constitute JNP, more information can be obtained.We are interested in the ability of classical Janus NPs to co-encapsulate the model drug pairs, and the dual phase release kinetics are quantified and adjusted by mathematic equations. Finally, we aim to explore the acute toxicity and morphological changes upon exposure to classical Janus NPs on the zebrafish larvae. Moreover, the fluorescence microscopy images showed that the biodistribution of nanoparticles is pretty consistent with the nanotoxicity and malformations determined in the larvae. This project verified that the multicompartmental supramolecular organizations are promising candidates for the co-encapsulation of the hydrophilic and hydrophobic active pharmaceutical ingredients
Allouch, Mohamed. "Nouveaux matériaux tensioactifs non ioniques monodispersés hydrogenés et fluorés sur la base d'aminoacides." Nancy 1, 1994. http://www.theses.fr/1994NAN10012.
Full textSauvage, Sophie. "Structures membranaires à base de tensioactifs fluorés non ioniques : phases aqueuse et émulsions-gels concentrées." Nancy 1, 1993. http://www.theses.fr/1993NAN10374.
Full textDenis, Cécile. "Utilisation de milieux aqueux a base de tensioactifs glycosidiques ou de sucres amphiphiles en synthese organique." Rennes 1, 1995. http://www.theses.fr/1995REN10171.
Full textDethoor, Célia. "Synthèse et propriétés de tensioactifs à base de glucose chélatant les métaux : application à la flottation." Amiens, 2013. http://www.theses.fr/2013AMIE0106.
Full textHeavy metals pollution of water and soils is an environmental and public health issue. Several technics exist to treat the contamined areas like flotation. Flotation is a technic allowing removal of metal ions with the action of surfactants and air bubbling. In this study, we realized the synthesis of new compounds based on octylglucoside, with chelating group on C6. We used nuclephilic substitution and copper catalyzed coupling. Interfacial properties were determined by the maximum bubble pressure method. The CMC of surfactants go from 14 to 46 mM. Flotation tests in laboratory were performed with different metal salts (Cd2+, Ni2+, Cr3+, As3+ and Pb2+) and the metal concentration were measured by ICP. The extracting coefficient of compounds depends on the structure of surfactant and metal salts. One of them is quite efficient for extraction of lead, nickel and cadmium. In fact, a good foaming capacity in presence of metal ions is a key step for maximal efficiency
Franceschini, Letizia. "Sviluppo di rivestimenti antibatterici per protesi di titanio a base di PEG silanizzato/ZnO nanostrutturato." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Find full textRopers, Marie-Hélène. "Étude structurale de Systèmes Moléculaires Organisés à base de tensioactifs fluorés non ioniques : application à l'immobilisation de biomolécules." Nancy 1, 2000. https://hal.univ-lorraine.fr/tel-01746458.
Full textAssfeld-Lamaze, Christine. "Etude des relations entre les propriétés lubrifiantes et le comportement physico-chimique d'émulsions à base de tensioactifs nonioniques." Nancy 1, 1994. http://www.theses.fr/1994NAN10432.
Full textGozlan, Charlotte. "Synthèses éco-compatibles de nouveaux composés amphiphiles biosourcés à base sucre et leurs applications en tant que tensioactifs et antimicrobiens." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10249.
Full textThe research work described in this manuscript is based on the green chemistry concept and within the frame of sustainable development which involve the use of raw materials from renewable resources and the development of eco-compatible process for the preparation of new products for food-processing, domestic or therapeutic applications. In this context, a new access to monosaccharide acetals and ethers (sorbitan and methyl glucoside) has been developed. The synthetic process is divided in two steps with an acetalisation or a transacetalisation as first reaction which allows to synthesize a new class of monosaccharide acetals. Then, a second step of acetal hydrogenolysis with palladium on charcoal and under hydrogen pressure has permitted access to sorbitan and methyl glucoside monoethers. Then, a one-step process and the use of intermediary short alkyl chain acetal as solubilizing agent has permitted to increase the yield and to consider an industrial development. Finally, these new molecules have been evaluated as surfactants, liquid crystals and antimicrobials and some of them have exhibited very attractive properties which could lead to potential applications in these fields
Turani-I-Belloto, Alexandre. "Synthèse de polymères poreux à base de PEG-DA par voie microfluidique et pour une application en tant qu'isolant acoustique." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0189/document.
Full textThe fabrication of thin, solid and insulating coatings containing small porous particles is the major challenge of these works. Several key points need to be raised to succeed. First, a good material for the particles has to be found, we chose a soft polymer, PEG-DA. Then, the choice of the synthesis routine to make porous polymers is crucial. A technique using UV photopolymerization and dissolution of sacrificial porogen (CaCO$_3$) will be used. Next, we will decide to make porous particles by microfluidics to obtain well controlled sizes and good monodispersity. The last step will be about the dispersion of those particles in a matrix to create coatings. Acoustics measurements will show the acoustic response of PEG-DA in ultrasounds. Moreover, this work will also permit us to study the frontal photopolymerization of transparent and scattering media and to present a method with Monte-Carlo simulations to describe conversion profiles of polymer as a function of intensity and path length. Other studies will present drying of PEG-DA hydrogels and dissolution of CaCO$_3$ through those hydrogels. A physical model will be proposed to describe the competition between kinetics and acid diffusion
Bellat, Vanessa. "Ingénierie d'un nouveau nanobiohybride à base de nanorubans de titanates pour la médecine régénérative." Thesis, Dijon, 2012. http://www.theses.fr/2012DIJOS056/document.
Full textThis research work is devoted to new nanohybrid engineering composed of titanate nanoribbons for regenerative medicine. Over a first phase, nanoribbons were synthesized by hydrothermal treatment and their morphological, structural and chemical features were defined. A fine characterization by means of different techniques of transmission electron microscopy mainly enabled to determine their thickness; dimension which had never been measured so far. Subsequently, titanate nanoribbons were functionalized by different home-made heterobifunctional PEG. Those polymers present at one of their extremities specific functional groups being able to couple with numerous biological molecules. Some collagen type peptides containing cellular recognition sites were grafted onto those extremities. The so-formed nanobiohybrid will permit cellular adhesion and proliferation favouring in fine tissue healing and regeneration. To evaluate new nanohybrid biological properties, titanate nanoribbons cytoxicity and aggregating power were determined by MTT tests, performed on two cell populations (fibroblasts and cardiomyocytes) and platelet aggregation tests (human blood). Finally, when used to promote healing process, the new nanobiohybrid was formulated in the form of sodium alginate hydrogel permitting a direct application on damaged tissues. To confirm the interest of this galenic form, initial in vivo tests were realized
Agach, Mickaël. "Synthèse et étude des propriétés structurales, physico-chimiques et fonctionnelles d'oligoesters tensioactifs branchés à base d'acide succinique bio-sourcé et de glycérol." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10082/document.
Full textThe synthesis and the study of new crop-sourced and branched amphiphilic oligoesters based on bio-sourced succinic acid, glycerol, fatty acids and other crop-sourced building blocks have considered for surfactive applications in various fields as substitutes for petrochemicals. The implemented strategy is part of an eco-design approach to obtain acceptable organoleptic, physico-chemical and functional properties comparable to those of benchmarks. At first, the impact of succinylation on the physico-chemical and functional properties of non-ionic surfactants derived from ethoxylated fatty alcohols, glycerol monolaurate and alkyl polyxylosides has been studied. In a second step, non-toxic and biodegradable poly(glycerol-succinic acid) oligomers, PGSs, were synthesized without solvent nor catalyst and characterized with the intention of developing new bio-sourced polar heads of surfactants. Mathematical models have been developed so as to extract the widest range of structural information such as the number-average degree of polymerization, DPn from the quantitative 13C NMR data. In the third phase, acyl poly(glycerol-succinic acid) oligomers or acyl PGSs were synthesized and studied. It has been shown that lauroyl derivatives form abundant and stable foams, exhibit a wide range of wetting powers and display excellent properties of micellar solubilization. Finally, to improve the physico-chemical and functional properties of the lauroyl PGSs obtained by catalyzed synthesis by increasing the homogeneity of the reaction mixtures, comonomers were used as copolymerizable solvents. Within the context of a tightening legislation, this type of bio-sourced macromolecules constitutes a promising platform paving the way for further chemical modifications and various grafting to target other potential applications
Boghi, Caterina. "Nuovo copolimero triblocco per applicazioni biomedicali a base di polilattico e contenente sequenze "PEG-like": sintesi e caratterizzazione allo stato solido." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/12222/.
Full textPasternak, Nicolas. "Synthèses de matériaux mésoporeux et nanoparticulaires plus écologiques à base de silicium et titane." Thesis, Cergy-Pontoise, 2017. http://www.theses.fr/2017CERG0911.
Full textSilica and titanium oxides are present in many fields (chemistry, environmental, medical, pharmaceutical, etc…). The main problem of these materials concerns the synthesis financial and environmental costs. In this work, the aim was to solve this problem. A new greener silica oxide nanoparticles synthesis was prepared. These nanomaterials have been analyzed by the conventional characterization methods in material sciences (N2 volumetric adsorption, Thermogravitometric Analysis (TGA),...). The viscoelastic properties of the reaction media were determined by micro-rheology. A strategy for the elimination of non-ionic surfactant families (poloxamers and polyethylene oxide) ) used as template in the synthesis of mesoporous materials based on silica (SBA-n, MSU-X, ....) was also implemented. This procedure allowed to recover the surfactants and to obtain materials with remarkable physicochemical properties identified by the same methods instrumentation. After functionalization of the surface, the washed materials appear to be more efficient in terms of adsorption of organic compounds as their calcined counterparts. Extended to titanium oxide, the washing process seems to produce from a percentage of TiO2 (> 70%) highly reactive materials in photocatalysis and with a high antibacterial power
Martinelli, Giulia. "Stampa 3D di un idrogelo a base di PEG-peptide contenente cellule mesenchimali staminali per la realizzazione di costrutti tissulari osteo-cartilaginei." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/12309/.
Full textFlores, González Maria del Rosario. "Efecto de la adición de biomasa procedente de Aloe arborescens a un agente encapsulante base ALG-PEG como preservador de un extracto." Tesis de Licenciatura, Universidad Autónoma del Estado de México, 2021. http://hdl.handle.net/20.500.11799/111432.
Full textCONSEJO MEXIQUENSE SE CIENCIA Y TECNOLOGÍA: Beca de titulación. UAEM/4561/2018/CIV: Beca de investigación
Shafqat, Numera. "Nuovo copoliestere multiblocco a base di acido 2,5-furandicarbossilico contenente sequenze PEG-like per la realizzazione di film compostabili per il packaging flessibile ecosostenibile." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16687/.
Full textBensaid, Fethi. "Nouvelles nanoparticules à base de conjugués polymériques biodégradables pour des applications en drug delivery." Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1766/.
Full textThis thesis is a collaboration between the LHFA and the CMC department (Chemistry Manufacturing and Control) of Sanofi at Vitry-sur-Seine, and aims to develop new nanocarriers based on biodegradable and biocompatible polymeric conjugates that could be used for the vectorization of active ingredient. In the first chapter, a bibliographic review is detailed to understand the principles of vectorization and to review the main achievements for the delivery of therapeutic agents by intravenous administration, particularly with biodegradable and biocompatible polymers, such as PLA and PEG. In the second chapter, benefiting from the ROP organic catalysis, new macromolecular conjugates based on PEG-PLA/Taxane are synthesized, with a particular architecture (Y-shape), positioning the PA between PLA and PEG blocks. Linear conjugates of PEG-PLA-taxane were also prepared to evaluate the influence of the architecture on the nanocarriers properties. The chemical composition of these nanoconjugates was precisely characterized using several analytical techniques (NMR, DOSY, UPLC, SEC. . . ). In the third chapter, the macromolecular conjugates were formulated in an aqueous medium to obtain nanoparticles with a "core-shell" conformation. The two different architectures allow to obtain stable NPs. Then, the API was localized into NPs using the NMR spectroscopy in D2O : API at the hydrophilic/hydrophobic interface for the Y-shape conjugates and in the center of the hydrophobic core for the linear conjugates. Finally, in vitro release of the API showed sustained and different profiles depending on the shape and on the nature of the spacer : the fastest release was obtained with the Y-shape structure and the diglycolic spacer
Zerkoune, Leïla. "Développement de nanovecteurs multicompartimentaux à base de cyclodextrines amphiphiles et de lipides pour des applications en nanomédecine." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA114837.
Full textThe key idea of this Ph.D. thesis is to introduce amphiphilic β-cyclodextrin molecules (βCD), obtained by bio-transesterification, within lipid mesophases in order to obtain multi-compartment plurimolecular nano-assemblies, which combine three essential functions for transport or delivery of therapeutic molecules: (i) capacity to incorporate a substance of interest through formation of inclusion complexes with the modified cyclodextrin; (i) biocompatibility and ability to easily pass the biological barriers; and (iii) possibility for co-encapsulation of a second substance of interest, a hydrophilic or a hydrophobic one, whose biological action is different from that provided by the first substance. The performed Ph. D. work focused on the β-cyclodextrin derivative βCD-C10 with an average degree of substitution of 7.5 of the secondary face of the macrocycle by hydrocarbon chains C10. The association of this derivative with three classes of amphiphiles was studied: (i) nonionic micellar surfactants (Brij 98, Polysorbate 80, n-dodecyl β-D-maltoside), (ii) a lyotropic nonlamellar lipid forming bicontinuous cubic mesophases (monoolein), and (iii) a phospholipid (dimyristoyl phosphatidylcholine), which self-ssembles into bilayer membranes permitting the production of vesicles.The employed physical-chemical approach involved different techniques for characterization of the mixed βCD-C10/lipid systems at molecular and supramolecular levels: cryo-transmission electron microscopy, X-ray diffraction, differential scanning calorimetry, UV-visible absorption spectroscopy, fluorescence spectroscopy, turbidimetry, and quasi-elastic light scattering.The obtained results indicated that the βCD-C10 derivative forms spontaneously (or via a very simple preparation protocol) plurimolecular mixed nano-assemblies with the three types of lipids. The topologies of the resulting nano-assemblies essentially depend on the chemical structures of the lipids and the degree of incorporation of the amphiphilic cyclodextrin (tubules, unilamellar or oligolamellar vesicles, and cubosomes). These assemblies, namely the mixed vesicles of nonionic surfactant/βCD-C10 and the cubosomes of mixed monoolein/P80/βCD-C10 compositions, are stable and capable of incorporation of hydrophobic guest substances
Korchia, Laetitia. "Auto-assemblage de copolymères amphiphiles photo-stimulables à base de polyoxazoline." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2016. http://www.theses.fr/2016ENCM0005/document.
Full textThree photo-responsive amphiphilic copolymer architectures (diblock, triblock and heterografted) based on polyoxazoline and coumarin photo-sensitive units are studied in this work. These copolymers self-assemble in water into spherical or ovalic nanoparticles and also supramicrometer helicoidal nanofibers. Depending on the macromolecular architectures, these morphologies are induced by crystallization of coumarin units or polyoxazoline-coumarin interactions. Moreover, the nanoparticle photo-response is examinated after the UV-exposure of coumarin units, that are able to reversibly dimerize according to the wavelength used. This photo-response varies with the copolymer structure and leads to (previous) photo-dimerization or photo-crosslinking phenomena. These latters present various photo-reversibility behaviors under UV and a maximal efficiency for triblock copolymers. The nanoparticle stability was additionally studied before and after UV-irradiation. In both cases, the nanoparticle stability is improved towards time and temperature with a maximal impact for the previous photo-dimerization (triblock). Finally, the crosslinking and the crystallization appear as brakes for the hydrophobic molecule entrapment, illustrated here by Nile Red, whereas diblock copolymers seem to be the most efficient systems. To conclude, previously photo-dimerized nanoparticles (triblock) are the best way combining stability, UV-efficiency and entrapment
Nguyen, Thi Bich Viet. "Synthèse et Caractérisation de POSS (Polyhedral Oligomeric SilSesquioxane) greffé POE. Application aux Systèmes Epoxy-Amine à base Aqueuse." Phd thesis, Université du Sud Toulon Var, 2010. http://tel.archives-ouvertes.fr/tel-00617530.
Full textPimentel, Delton Martins. "Desenvolvimento e caracteriza??o de filmes eletroativos a base de PAni/rGO-PEG-NH2/HRP visando a constru??o de um biossensor enzim?tico para detec??o de H2O2." UFVJM, 2013. http://acervo.ufvjm.edu.br:8080/jspui/handle/1/292.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes)
Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG)
Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)
No presente trabalho fabricou-se um material comp?sito ? base de polianilina (PAni), grafeno(rGO) e Horseradish peroxidase (HRP), visando o desenvolvimento de uma nova plataforma para detec??o de per?xido de hidrog?nio (H2O2) com uma alta sensibilidade. O grafeno utilizado foi produzido a partir da redu??o do ?xido de grafite (GO) por redu??o em forno de micro-ondas, que por sua vez foi sintetizado pelo m?todo de Laura J. Cote et al. Posteriormente, o nanomaterial foi modificado quimicamente com O,O?-Bis(2-aminoetil)-polietilenoglicol, produzindo assim grafeno funcionalizado com grupo amino (rGO-PEG-NH2). Ap?s esta etapa, foi produzido o comp?sito PAni/rGO-PEG-NH2 por via potenciodin?mica e o mesmo foi utilizado como substrato para fabricar um sensor para H2O2 atrav?s da imobiliza??o da enzima HRP sobre o pol?mero produzindo-se assim um material comp?sito. Os experimentos eletroqu?micos foram realizados em uma cela eletroqu?mica com capacidade para 10 mL com tr?s eletrodos, sendo o eletrodo de refer?ncia Ag/AgCl, contra eletrodo de fio platina, e eletrodo de trabalho de Au (0,071 cm2). Estudos comparativos entre os processos redox da PAni e PAni/rGO-PEG-NH2 realizados por voltametria c?clica e imped?ncia eletroqu?mica deixaram evidente que o material comp?sito apresenta uma maior densidade de corrente bem como uma menor resist?ncia ? transfer?ncia de carga em altos e baixos potenciais. Por fim, com o prop?sito de avaliar o comportamento eletroqu?mico do sistema a duas dimens?es 2D, foram realizadas imagens eletroqu?micas da PAni bem como da PAni/rGO-PEG-NH2 por Microscopia Eletroquimica de Varredura (SECM, do ingl?s Scanning Electrochemical Microscopy) utilizando uma c?lula eletroqu?mica de 3 mL com quatro eletrodos. Conforme observado, a PAni/rGO-PEG-NH2 apresenta regi?es com alta densidade de corrente devido ao maior feedback positivo em compara??o ? PANI na aus?ncia do grafeno, al?m de proporcionar um transporte mais efetivo de pr?tons para dentro e para fora da matriz polim?rica; tornando assim o material bastante promissor para imobiliza??o de esp?cies com carga formal positiva. Ap?s a inser??o da HRP ao material comp?sito os estudos realizados com o biossensor resultou em uma sensibilidade de 44 ?A mM?1 e LOD de 0,31 ?M e LOQ de 0,94 ?M para a detec??o de H2O2, sendo estes valores muito superiores aos de outros trabalhos presentes na literatura e muito superior ao obtido pelo pol?mero condutor aplicado isoladamente com a enzima.
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013.
ABSTRACT In the present work a composite material based on polyaniline (PAni), graphene (rGO) and Horseradish peroxidase (HRP) was fabricated, aiming the development of a new platform for the detection of hydrogen peroxide (H2O2) with high sensitivity. The graphene used in this work was produced from the reduction of graphite oxide, using a microwave oven. The graphite oxide was synthesized by the method of J. Laura Cote et al. Subsequently, the nanomaterial was chemically modified with O, O'-Bis (2 - aminoethyl) polyethylene glycol, thus producing graphene functionalized with amino groups (rGO / PEG). After this step, the composite PAni/rGO-PEG-NH2 was produced by potentiodynamic method and it was used as a substrate to fabricate a sensor for H2O2 by immobilizing the enzyme HRP over the polymer, thus producing a composite material. Electrochemical experiments were performed in an electrochemical cell for up to 10 mL, with three electrodes: Ag / AgCl was used as the reference electrode; platinum wire as the counter electrode and the working electrode was an Au electrode with an area of 0.071 cm2. Comparative studies of the redox processes of PAni and PAni/rGO-PEG-NH2, performed by cyclic voltammetry and electrochemical impedance spectroscopy, made it clear that the composite material has a higher current density and a lower charge transfer resistance in high and low potentials. Finally, in order to evaluate the electrochemical behavior of the two dimensional (2D) system, electrochemical images were taken of PAni and PAni/rGO-PEG-NH2 by Scanning Electrochemical Microscopy (SECM) using an electrochemical cell with 3 mL and four electrodes. As noted, the PAni/rGO-PEG-NH2 presents regions with high current density due to the higher positive feedback compared to PAni in the absence of graphene, besides it promotes a proton transportation more effective, to the inside and the outside of the polymeric matrix. After insertion of the HRP enzyme to the composite material, the studies performed with the biosensor resulted in a sensitivity of 44 ?A mM-1, LOD 0.31 and LOQ 0.94 mM for the detection of H2O2, being these values much higher than other works found in the literature, and much higher than the one obtained with the conducting polymer used only with the enzyme.
Fressancourt-Collinet, Marion. "Ammonium quaternaires amphiphiles à contre-ion catalytique : Physicochimie et application à l’oxydation en microémulsion." Thesis, Lille 1, 2011. http://www.theses.fr/2011LIL10203/document.
Full textCatasurfs are cationic surfactant bearing a catalytic counterion and have been designed for the formulation of three-phase oxidative microemulsion systems whose purpose is the H2O2 oxidation of organic substrates. Physicochemical properties of amphiphilic quaternary ammonium in aqueous solution have been investigated with various counterions, showing the dependence of anion polarisability and hydration on the amphiphilic properties of the surfactant. The phase behavior of water/solvent/surfactant ternary mixtures has been examined according to various parameters (counterion, solvent, quaternary ammonium structure, addition of non ionic surfactant), and particularly the behavior of catalytic surfactants with H2O2. Anion peroxydation, by a variation of its polarisability, radically changes its water and oil affinities, and its phase behavior. The various observations led us to elaborate three-liquid-phase reaction media based on quaternary ammonium molybdate or tungstate, with various solvents (aromatic and alkyl acetates) and under pH control. This type of medium has several practical major advantages: large water/oil interface in the microemulsion phase, simplicity of implementation with only three components, ease of reaction medium treatment with the catalyst lying in the middle phase and the product(s) in the organic phase, instantaneous phase separation thanks to ultra-low interfacial tensions. The efficiency of these three-phase microemulsion systems has been evaluated and validated for the oxidation of sulfides by the H2O2/MoO42- catalytic system, and for the epoxidation of alkenes with H2O2/WO42- in acidic media
Souza, Marina Claro de. "Micelas de longo tempo de circulação contendo tamoxifeno como sistema nanocarreador para otimização da terapia do câncer de mama." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/60/60137/tde-23052018-143506/.
Full textBreast cancer is the second main cause of death among women in development countries due to their high malignance grade. The treatment is mainly based on hormonal therapies, once the cells of the majority of mammary tumors express a high number of hormone receptors, responsible for the tumor growth. Tamoxifen is a selective estrogen receptor modulator drug, acting through the antagonism of the activation of the estrogen receptor, reducing thus the tumor growing rate. Despite the treatment with tamoxifen is highly effective, it is related to severe dose-dependent side effects. The central objective of this work was the development of long time circulation micelles containing tamoxifen, prepared with the phospholipid DSPEPEG(n) and TPGS, a vitamin E derivative, by the method of solvent evaporation, for intravenous administration, able to allow a higher accumulation of the drug at the tumoral site due to their nanometric dimensions, leading to a reduction in the dose and consequently in the side effects. The determination of the encapsulation efficiency and the quantification of tamoxifen in the in vitro release profile study from the micellar systems were carried out by HPLC, using methods previously validated. The best results were achieved with the formulations based on DSPE-PEG(2000) and TPGS, which showed mean particle diameter less than 20 nm, low polydispersity index and encapsulation efficiency ranging from 70 to 95%. The transmition electronic microscopy pointed the spherical shape and proved the homogeneity of particle size. The systems were also characterized by infrared spectrophotometry to identify eventual interactions among the components of the formulations. The in vitro release profile study showed that after 168 h, a maximum of about 30% of tamoxifen was released, evidencing that the increase of the TPGS amount in the formulation reduced the amount of tamoxifen released. The low rate of in vitro release drug suggests that the major part of the drug will remain encapsulated during the period of blood permanence, favoring the arrival of the intact nanostructure at the tumoral site. During the evaluation of the plasmatic concentration profile, conducted with Wistar rats, it was not possible to detect neither the tamoxifen nor its main metabolite, suggesting that the intact micelles may have quickly accumulated in the organs.
Le, Dévédec Frantz. "Développement de tensioactifs à base d’acides biliaires pegylés pour des applications pharmaceutiques." Thèse, 2013. http://hdl.handle.net/1866/10130.
Full textBile acids are natural compounds and may have potential for pharmaceutical applications. Their structures provide an interesting platform for polymerization to obtain well-defined architectures. The anionic polymerization of oxirane derivatives, mainly PEG derivatives, endowed new aggregation properties and improvement of biocompatibility of the new amphiphilic polymers based on bile acids. A library of pegylated bile acids (BA(EGn)x) was prepared for the formulation of lipophilic drugs. The aqueous physicochemical behaviors of these derivatives (modulation of the length (2 < n < 19) and the number (2 < x < 4) of PEG arm) were investigated. In order to improve the bioavailability of insoluble active compounds (itraconazole, an antifungal drug), a binary system based on the association of BA(EGn)x and oleic acid, formed self-emulsifying drug delivery systems. The in vitro evaluation of cell toxicity and solubilization capacities of the BA(EGn)x systems followed by the in vivo evaluation in rats of the pharmacokinetic parameters demonstrated the advantages of our self-assembled system for controlled drug delivery for both oral and intravenous administration. Star-shaped block copolymers of pegylated cholic acid (CA(EGn-b-AGEm)4) were prepared by the introduction of a second hydrophobic block of PAGE poly(allyl glycidyl ether). They demonstrated thermosensitivity (8 oC < LCST < 37 oC) in aqueous solution, suggesting a mechanism based on the formation of aggregates in two steps. The PAGE block with pendant groups may facilitate futher functionalization. The thiolation of allyl yields a new class of charged PEGylated star polymers (with multiple amines or carboxylic groups). CA(EGn-b-AGEm-NH2)4 and CA(EGn-b-AGEm-COOH)4 derivatives showed self-assembled structures in solution with temperature and pH responsiveness, respectively. This functionalization may lead to broader application of pegylated star derivatives in DNA transfection systems, siRNA delivery systems or as selective delivery system (pH-dependent).
Jung, Lin Din, and 林定宗. "Synthesis of PCL-PEG-PCL Triblock Copolydiol Base Polyurethane and Their Applications of Water Vapor Permeability and Water Resistence on Nylon Fabrics." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/49465018537979125783.
Full textRode, García Teresita. "Étude de l’influence de différentes méthodes de fabrication sur l’architecture et les propriétés physico-chimiques des nanoparticules à base de PEG-b-PLA." Thèse, 2017. http://hdl.handle.net/1866/20551.
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