Synthèse de nouveaux WPU (waterborne polyurethane) cationiques à partir du caoutchouc naturel (NR), et évaluation de leurs propriétés adhésives pour des surfaces de type cuir. Ces WPU ont été obtenus par réaction du caoutchouc liquide hydroxy téléchélique (HTNR), de toluene-2,4-diisocyanate (TDI), N-methyl diethanol amine (NMDEA, en tant qu’émulsifiant) et d’éthylène glycol (EG, extenseur de chaîne). Ces structures biosourcés sont développés comme alternatives aux WPU issus des ressources fossiles à fort impact environnemental. Les effets de cinq paramètres ont été étudiés, à savoir la quantité d'émulsifiant (de 0 à 2,25 mole), celle d’éthylène glycol (de 0 à 3 moles), le Mn du HTNR (de 100 à 3000 g/mole), l'indice NCO (de 100 à 150) et le taux d’époxydation des HTNR précurseurs (de 0 à 30%). Il a été en outre démontré que la stabilité des dispersions aqueuses pour les formulations optimales dépassait les 10 mois. La géométrie des particules dispersées a été étudiée, démontrant un aspect sphérique et une taille à l'échelle nanométrique. Ainsi, plusieurs facteurs ont été étudiés pour évaluer les propriétés adhésives optimales sur bandes de cuir (Mn, pourcentage d’'époxyde). Des tests standard (Peel test et Lap Shear test) ont été utilisés et les valeurs obtenues comparées avec celles issus de formulations adhésives commerciales avec ou sans solvants. Au bilan, une formulation optimale a été déterminée (Mn = 3000 g/mole, LR epoxydation = 10%, NMDEA 5.67%wt, NCO index de 100 et 1 mole d’EG) avec cuisson préalable des systèmes à 70°C. Ce WPU a montré une force d’'adhésion supérieure à toutes les formulations commerciales testées. / Novel cationic waterborne polyurethane (cWPU) based on natural rubber (NR) have been prepared by the polymerization reaction of hydroxyl telechelic natural rubber (HTNR), toluene-2,4-diisocyanate (TDI), N-methyl diethanol amine (NMDEA, as emulsifier), and ethylene glycol (EG, chain extender). The polyol structures have been developed as alternative to produce cWPUs derived from a renewable resource. The effects of five parameters were studied – amount of NMDEA (0 – 2.25 mole), amount of EG (0 – 3 mole), molecular weight of HTNR (~1000 – 3000 g/mole), NCO index (100 – 150), and epoxide content on eHTNR soft segment (0 – 30%). The appearance of cWPU dispersion was milky-blue with long shelf life time, more than 10 months. Particle of prepared cWPU were spherical shape in the nano range size. The adhesive properties of cWPUs on the real leather surface, taking into account of the different molecular weights of HTNR and different degree of epoxide content on HTNR, were tested by lap shear test and 180 degree peel test and compared with commercial adhesives. Overall, to balance the stability and adhesive strength, the best conditions for preparing cWPU adhesive for leather application in this study was from the composition of HTNR3000 with epoxide content of 10%, NMDEA 5.67%wt, NCO index of 100 and 1 mole of EG. in condition of curing at 70 °C. In comparison to non-solvent based and solvent based commercial adhesives, the adhesive strengths of these synthesized cWPU adhesive were superior.

La mucoviscidose est une maladie monogénique, caractérisée par des mutations survenant au niveau du gène CFTR (Cystic Fibrosis Transmembrane Conductance Regulator). Le clonage en 1989 du gène CFTR a permis d’envisager de traiter cette maladie par thérapie génique. Cela consiste à transférer à l’aide d’un vecteur, une version normale du gène CFTR dans les cellules atteintes des patients. En raison de la gravité des complications pulmonaires, c’est l’épithélium respiratoire qui constitue aujourd’hui le tissu cible pour le transfert de gènes. Le principe de la thérapie génique est évidemment très séduisant et un certain nombre d’essais cliniques ont d’ores et déjà été réalisés. La thérapie génique nécessite des outils de vectorisation efficaces et compatibles avec une utilisation répétée en clinique.Mon sujet de thèse a porté donc sur le développement, la biodistribution et l’optimisation de vecteurs synthétiques (lipides cationiques) pour le transfert de gènes dans l’épithélium respiratoire. Au cours de mes travaux, nous avons donc pu mettre au point des lipophosphoramidates KLN47 fluorescents utiles pour les études de biodistribution in vivo. Comparés au KLN47 non fluorescent, ces nouveaux composés présentent les mêmes propriétés physicochimiques, à savoir une taille relativement petite et un potentiel zêta positif. Sur lignées cellulaires, nous avons montré que les nouvelles formulations étaient aussi efficaces que le KLN47, et pas ou peu toxiques. Ensuite, sur modèle animal, les profils de biodistribution de lipoplexes pégylés et non-pégylés ont été comparés après injection systémique. Les profils de biodistribution des lipoplexes pégylés et non-pégylés étaient similaires, cependant, la pégylation des complexes a conduit à une circulation prolongée dans la circulation sanguine, alors que l’expression du transgène (luciférase) était équivalente dans les deux cas. De plus, l’activité luciférase était similaire à celle obtenue avec le KLN47 non fluorescent. Nous avons ainsi démontré que l’ajout des sondes lipidiques fluorescentes dans la solution liposomale du KLN47, ne modifie pas ses propriétés physicochimiques et transfectantes. L’ensemble des résultats montre que nous disposons d’outils prometteurs pour les études de biodistribution in vivo. D’autres molécules ont également été testées avec succès. / Cystic fibrosis is a monogenic disease characterized by mutations occurring at the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene. The clonining in 1989 of the CFTR gene has enabled to consider treating this disease by gene therapy. This consists of transferring a normal version of the CFTR gene in the affected patients’ cells, using a vector. Due to the severity of pulmonary complications, it is obvious that the respiratory epithelium constitutes the target tissue for the gene transfer. The principle of gene therapy is indeed very attractive and a number of clinical trials have already been made. Gene therapy requires vectorization tools that are efficient and compatible with repeated clinical use.My thesis has focused on the development, biodistribution and optimization of synthetic vectors (cationic lipids) for gene transfer in the respiratory epithelium. During my work, we were able to develop useful fluorescent KLN47 lipophosphoramidates for in vivo biodistribution studies. Compared to non fluorescent KLN47, these new compounds exhibit the same physicochemical properties: a relatively small size and a positive zeta potential. On cell lines, we found that the new formulations were as effective as the KLN47, with little or no toxicity. Then, in animal models, the biodistribution profiles of pegylated and non-pegylated lipoplexes were compared after systemic injection. The biodistribution profiles of pegylated and non-pegylated lipoplexes were similar. However, the pegylation of the complex resulted in prolonged circulation in the bloodstream, whereas transgene expression (luciferase) was equivalent in both cases. In addition, luciferase activity was similar to that obtained with the non-fluorescent KLN47. We have demonstrated that the addition of fluorescent lipid probes in the liposomal solution KLN47, does not change its physicochemical and transfectant properties. The overall results show that we have promising tools for in vivo biodistribution studies. Other molecules have also been tested successfully.

Made available in DSpace on 2014-06-11T19:30:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-13Bitstream added on 2014-06-13T19:19:37Z : No. of bitstreams: 1 alves_fr_dr_sjrp.pdf: 2029517 bytes, checksum: f737742cea44bc8699abdd17def3823d (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Estudos de calorimetria diferencial de varredura (DSC) e fluorescência de estado estacionário da sonda Vermelho do Nilo indicam a formação de vesículas de DODAX (X = Cl- ou Br-) em concentrações de surfactantes tão baixas quanto 10 µM. Estas vesículas foram denominadas microvesículas (µV), cuja Tm diminui monotonicamente com a concentração de DODAX até valores de Tm das vesículas tradicionais preparadas em 1.0 mM do surfactante. O efeito do contra-íon (Br- e Cl-) no comportamento termotrópico de fase das vesículas mistas de DODAB-DODAC foi investigado por DSC, condutimetria e espalhamento dinâmico de luz (DLS). Observou-se que a Tm aumenta sigmoidalmente de 45.8 a 48.9 oC com a fração molar de DODAC (xDODAC), com um ponto de inflexão no ponto eqüimolar. A condutividade e o diâmetro hidrodinâmico das vesículas variam muito pouco com xDODAB, indicando que a densidade superficial de carga das vesículas de DODAX é semelhante entre si, e o efeito do contra íon na Tm de DODAX se deve a interações específicas desses contra-íons na interface das vesículas. Medidas de DSC, fluorescência e turbidez de misturas de DODAB-DDAB indicam que as vesículas de DODAB têm maior afinidade por DDAB do que o oposto, resultando na formação de duas populações de vesículas mistas de DDAB-DODAB, com propriedades distintas. Além disso, medidas de fluorescência mostraram que a presença de pequena quantia de DODAB incorporado nas vesículas de DDAB causa um efeito significante na emissão da sonda devido ao aumento do tamanho das vesículas, sugerido por medidas de turbidez. O estudo dos sistemas DODAB/CnTAB/água na concentração total de surfactante igual a 1,0 e 5,0 mM, variando a concentração de CnTAB, e também mantendo a concentração de DODAB fixa em 1,0 mM, revelou uma forte dependência do comprimento da cadeia de hidrocarbonetos... / Differential scanning calorimetry (DSC) and fluorescence of the probe Nile Red studies reveal the formation of DODAX vesicles (X = Br- and Cl-) at surfactant concentrations as low as 10 µM. These vesicles were referred to as microvesicles (mV), whose Tm decreases monotonically with increasing DODAX concentration to the value for the ordinary vesicles at 1 mM. The effect of counterion (Br- and Cl-) on the thermotropic phase behavior of mixed DODAB-DODAC vesicles were investigated by differential scanning calorimetry (DSC), conductimetry and dynamic light scattering (DLS). Tm increases sigmoidally from 45.8 to 48.9 oC with DODAC molar fraction (xDODAC), with an inflection point at the equimolarity. The conductivity and the apparent hydrodynamic diameter vary little with xDODAB, indicating that the surface charge density is similar for DODAX, evidencing that the effect of counterion on Tm is due to the counterion specific interactions. DSC, fluorescence and turbidity measurements indicate a higher affinity of DDAB for DODAB vesicles than the reverse, resulting in two populations of mixed DDAB-DODAB vesicles with different properties. Besides, fluorescence measurements show that the presence of a small amount of DODAB in DDAB vesicles causes a pronounced effect on the Nile Red emission, due to the increase in vesicle size, as suggested from turbidity results. The study of DODAB/CnTAB/água systems at 1.0 and 5.0 total surfactant concentration, and varying CnTAB concentrations with constant 1.0 mM DODAB revealed a strong dependence of the chain length n and relative concentration of the surfactante in the properties of mixed DODAB-CnTAB vesicles. This study allowed analyzing the thermotropic phase behavior containing different amount of DODAB, and the mechanism of vesicle-micelle transition with increasing CnTAB concentration, below and above CMC... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:31:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-06-07Bitstream added on 2014-06-13T19:40:48Z : No. of bitstreams: 1 lopesfilho_fc_dr_sjrp_parcial.pdf: 183424 bytes, checksum: 8601f6f72a7635a3c9ada79092a5873d (MD5) Bitstreams deleted on 2015-06-25T13:01:06Z: lopesfilho_fc_dr_sjrp_parcial.pdf,. Added 1 bitstream(s) on 2015-06-25T13:03:24Z : No. of bitstreams: 1 000694954_20160706.pdf: 183130 bytes, checksum: 1526b9f9e1347a4fb71fe218102cf0ba (MD5) Bitstreams deleted on 2016-07-25T13:17:36Z: 000694954_20160706.pdf,. Added 1 bitstream(s) on 2016-07-25T13:18:45Z : No. of bitstreams: 1 000694954.pdf: 1071220 bytes, checksum: ead8820e5de7c1e29fdd2ec0459005b1 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Peptídeos antimicrobianos são moléculas biologicamente ativas que, geralmente, tem as membranas fosfolipídicas como alvo primário. Resultados de diferentes técnicas experimentais têm sugerido que esses peptídeos permeabilizam as membranas pela formação de poros. Parte dos peptídeos caracterizados apresentam especificidade de disrupção para membranas de bactérias, em detrimento das membranas dos hospedeiros. Essa característica tem atraído a atenção da comunidade científica internacional, porque indica que estas moléculas podem ser modelos para o desenvolvimento de novos antibióticos, portanto o entendimento do mecanismo de ação, ou seja, do mecanismo de formação de poro, tem extrema importância. Simulações por Dinâmica Molecular foram produzidas para investigarmos o impacto que peptídeos antimicrobianos da família Mastoparano tem sobre membranas lipídicas modelo. Dois cenários foram explorados: (i) de baixa concentração peptídeo/lipídeo, P/L=1/128, que consistia de simulações fine-grained das interações de um peptídeo com uma bicamada pura de 128 lipídeos aniônicos (POPG) ou zwiteriônicos (POPC); (ii) de alta concentração, P/L=1/21, que abordava as interações de seis peptídeos com uma bicamada mista de 128 lipídeos POPC/POPG (1/1) usando uma modelagem coarse-grained. Tomando o peptídeo MP1 como caso paradigmático, verificamos que em baixo P/L é possível sugerir que sua característica seletiva surge da capacidade de coordenar e perturbar maior número de lipídeos em membrana aniônica comparada à neutra. Essa capacidade fica acentuada nas simulações com membrana mista, onde a atração dos lipídeos aniônicos pelos peptídeos catiônicos guiou a separação local e a formação de domínios de lipídeos aniônicos, o que facilitou o afinamento local da membrana e a formação de poro transmembrânico. Esses achados ajudam a explicar como peptídeos / Antimicrobial peptides are biologically active molecules that, usually, have the phospholipid membranes as a primary target. Results from different experimental techniques have suggested these peptides permeabilize membranes by the pore formation. Part of the characterized peptides have specificity of disruption for bacterial membranes, instead of host membrane. This feature has attracted the attention of the international scientific community, because it indicates that these molecules can be models for the development of novel antibiotics, so understanding the mechanism of action, ie, the mechanism of pore formation, is extremely important. Molecular dynamics simulations were performed to investigate the impact of antimicrobial peptides from the Mastoparano family have on model lipid membranes. Two scenarios were explored: (i) of low peptide/lipid concentration, P/L=1/128, which consisted of fine-grained simulations of the interactions of a peptide with a pure bilayer of 128 anionic (POPG) or zwitterionic (POPC) lipids; (ii) of high concentration, P/L=1/21, which addressed the interactions of six peptides with a mixed bilayer of 128 POPC/POPG (1/1) lipids, using a coarse-grained modeling. Taking the MP1 peptide as a paradigmatic case, we found that in low P/L is possible to suggest that its selective feature arises of its ability to coordinate and disturb large number of lipids in the anionic membrane compared to neutral one. This ability is accentuated in simulations with mixed membrane, where the attraction of the anionic lipids by the cationic peptides led to the local segregation and formation of POPG lipid domains, which facilitated the local thinning of the membrane and the formation of transmembrane pore. These findings help to explain how short peptides, such as MP1, are able of forming pores in a membrane whose thickness is larger than the length of the peptide

Les cannabinoides (CBs) et plus spécifiquement les agonistes des récepteurs CB2 ontdémontré leurs propriétés analgésiques, sans effet psychotrope comparés auxagonistes CB1. Les CBs sont généralement des composés lipophiles et non “drug-like”présentant une faible biodisponibilité. Afin d’évaluer de nouveaux CB2 agonistesd’origine synthétique développés par notre laboratoire, sur des modèles in vivo dedouleur neuropathique, une stratégie de formulation précoce a été mise au point et apermis le développement de quatre systèmes de délivrance d’actif. Une étudepharmacologique d’efficacité a été conduite avec notre tête de série MDA7, formulédans des complexes d’inclusion avec des cyclodextrines (CDs), des liposomes et unesolution micellaire administrés par voie parentérale. Le concept à base de CDs adémontré une plus forte activité anti nociceptive. Une étude de compréhension dumécanisme d’inclusion de MDA7 dans le complexe supramoléculaire formé avec lesCDs a été menée. Des systèmes auto-émulsionnables (SEDDS) ont également étéutilisés pour une administration orale afin d’étudier le profile pharmacocinétique deMDA7. Des nanocapsules (NCs) polymériques et cationiques ont également été développéesafin de stabiliser un phytocannabinoide, CB2, en vue d’une administration in vivo. Desétudes pour caractériser et évaluer l’influence des paramètres affectant la formation desNCs préparées par nanoprécipitation ont été conduites. Nous avons étudié lapropension des NCs développées à former des interactions ioniques avec desmacrocycles anioniques tels que les sulfobutylether-β-cyclodextrines ou, desinteractions électrostatiques avec les cucurbit[n]urils / Cannabinoids (CBs) and particularly CB2 agonists have been shown to reduce pain andinflammation without eliciting any apparent psychotropic effect conversely to CB1agonist compounds. CBs candidates are usually lipophilic non drug-like compoundswith poor bioavailability. To serve the purpose of evaluating new synthetic CB2 agonistsdeveloped by our group, on in vivo neuropathic pain models, an enabling formulationstrategy has been set up and four Drug Delivery Systems (DDS) developed. Forparenteral administration, cyclodextrin (CD)-based inclusion complexes, liposomes andsurfactants/co-solvents micellar solution have been investigated whereas Self-Emulsifying DDS (SEDDS) was selected for oral administration. A pharmacologicalstudy conducted with lead compound MDA7, formulated in CD-based DDS resulted inthe higher antinociceptive activity. A comprehensive study of the inclusion mechanismof MDA7 in the CD supramolecular complexes prepared was carried out. MDA7pharmacokinetic profile was also generated formulated in micellar solution and SEDDS.Besides, cationic polymeric nanocapsules (NCs) have been designed to serve as aprotective DDS for oral administration of a dietary phytocannabinoid CB2 agonist.Studies were undertaken to characterize and evaluate the influence of differentparameters on NCs formation prepared by nanoprecipitation. The cationic NCsdeveloped have been explored for their property to yield proportion of counterioniccondensation in the presence of macrocycles bearing anionic groups such assulfobutylether-beta-cyclodextrin or to form electrostatic interactions/host-guestcomplexion with cucurbit[n]uril.

Foram investigadas através da técnica de absorção eletrônica Uv-Vis e emissão de fluorescência a interação entre uma série de porfirinas e zinco-porfirinas com o polímero de eumelanina sintética obtida pela auto-oxidação da L-DOPA (dihidroxi-fenilalanina). Ocorre a formação de dois complexos na interação entre as porfirinas catiônicas e a eumelanina. Um complexo mais fraco em concentrações mais baixas e intermediárias de eumelanina, e um complexo mais forte em concentrações maiores. Estes complexos podem ser observados pelas variações obtidas nos espectros de absorção em função da concentração da melanina. A eumelanina suprime eficientemente a fluorescência das porfirinas catiônicas, em um processo de supressão por esfera de ação. Este processo ocorre particularmente para os complexos fracos entre a porfirina e a eumelanina, podendo ser inferido pela natureza de polieletrólito da eumelanina que deve apresentar uma ampla superfície de contato carregada negativamente, facilitando a orientação das porfirinas em uma disposição planar em relação ao polímero. A determinação das constantes de supressão estáticas aparentes (KEA) mostra que os substituintes alquílicos influem consideravelmente na formação destes complexos com a eumelanina. As diferentes interações são devidas aos fatores estruturais tais como dimensão da porfirina, polarização dos substituintes e formação de interações de natureza hidrofóbica. As zinco-porfirinas são de forma geral menos suprimidas que as bases livres. Este comportamento pode ser uma evidencia da aproximação planar em relação ao polímero da melanina, uma vez que zinco porfirinas apresentam moléculas de água ligadas axialmente, logo estas moléculas coordenadas axialmente impediriam uma aproximação mais efetiva. Foi realizado um estudo da formação de filmes baseados na técnica de auto-montagem eletrostática entre as porfirinas e a melanina utilizando como substrato o vidro. Observa-se que a adsorção das porfirinas em vidro é diferenciada sendo a TBzPyP a base livre que apresenta a maior adsorção. Pelos espectros de emissão dos filmes de porfirina em vidro foi possível verificar que alguns derivados interagem com uma participação mais efetiva dos piridínios que outros em que a interação é menos direcionada. Nos filmes porfirina melanina também é observada a supressão de fluorescência da porfirina. A diferença na magnitude de supressão nos filmes sugere que estes derivados possam ser utilizados em sistemas de diagnóstico relacionados à detecção de tumores melanóticos. Em um estudo paralelo, foram investigadas as propriedades de fotoisomerização de grupos azobenzênicos coordenados axialmente a uma ftalocianina de Silício(IV). Este sistema apresenta fotoisomerização E-Z e isomerização térmica e sensibilizada para o processo Z-E. As conversões E-Z e Z-E seguem uma cinética de primeira ordem, sendo o processo térmico Z-E cerca de dez vezes mais lento que o fotoquímico E-Z. A intensidade de fluorescência da ftalocianina é dependente do estado de isomerização dos grupos axiais, sendo que a forma E apresenta maior emissão de fluorescência que a forma Z. Portanto este sistema se constitui em um dispositivo molecular do tipo “on-off”, onde a intensidade de fluorescência pode ser controlada por um estímulo externo, no caso o comprimento de onda de excitação para a reação E-Z direta ou Z-E sensibilizada. / In this work we have investigated the interaction between a series of cationic porphyrins and zinc-porphyrins and the synthetic eumelanin polymer obtained by the auto-oxidation of L-DOPA (dihidroxy-phenylalanine) by means of UV-Vis and fluorescence emission techniques. Weak and strong porphyrin-melanin complexes are formed, and the evolution from weak to strong complexes can be monitored by the UV-Vis changes in the pophyrin spectra as the melanin concentration increases. The porphyrin fluorescence emission is quenched efficiently by eumelanin in a “quenching sphere of action” mechanism. This quenching sphere of action process is mainly observed for the weak complexes, and can be rationalized considering the polyelectrolyte nature of the eumelanin polymer which provides a broad contact area coated negatively, that enables a planar approximation of the porphyrins. The apparent static quenching constants (KEA) show that the nature of the alkyl substiutents markedly influences the complex formation. Total porphyrin size, different polarization induced by substituents and specific hydrophobic interactions are probably responsible for the different porphyrin – melanin association, which in turn reflects in the quenching properties of each particular porphyrin - melanin complex. The corresponding Zinc-porphyrins are less efficiently quenched by eumelanin, probably due the fact this molecules are axially coordinated by a water molecule, precluding a more close approximation between zinc-porphyrin and the eumelanin polymer. Electrostatically self-assembled films of porphyrins and eumelanin on glass have been studied. Different porphyrin adsorption on glass were observed, and TBzPyP derivative shown the highest adsorption in the investigated porphyrin series. Fluorescence emission suggests different interaction properties of the adsorbed pophyrin on glass, with specific pyridinium participation for some porphyrin derivatives. Fluorescence quenching of the porphyrins is observed in porphyrin – melanin films. The differences observed in the quenching for each derivative suggest a possible application of these compounds for diagnostic procedures related to melanotic tumors. In a complementary study, have been investigated the photoisomerization properties of a Si(IV)-phthalocyanine axially coordinated by azobenzene groups. Photochemical E-Z and thermal and sensitized Z-E isomerization processes were observed. Both E-Z photochemical and Z-E thermal follow first-order kinetics. Z-E process as expected is considerably slower than E-Z. The pthalocyanine emission is dependent on the isomerization state of the apendent azobenze groups, and the E form is more emissive than the Z form. This system can be considered a molecular device since the emission properties of the phthalocyanine moiety can be modulated by the isomerization state of the axially coordinated azoarenes, creating an on-off (E-Z states) fluorescence signal, and differently from other reported systems the recovery of the initial state does not depend only on the rate of the thermal reaction, since it can be controlled by a sensitized mechanism. This system seems promising taking into account the stability of the axially coordinated moieties, the greater versatility in the achievement of the desired isomerization state and the broad spectral region considering both direct and sensitized excitation.

Polímeros e copolímeros hidrossolúveis a base de acrilamida e seus derivados são sintetizados e aplicados principalmente como floculantes, auxiliando na remoção de sólidos finos presentes em águas residuais e industriais. As poliacrilamidas, como são assim chamadas, podem se apresentar em sua forma neutra ou contendo diferentes cargas iônicas (positivas ou negativas) em sua composição em função do tipo de aplicação específica. As poliacrilamidas são sintetizadas, em sua grande maioria, através de emulsões inversas via polimerização radicalar, visando à elevada massa molar do polímero formado. A formulação da poliacrilamida catiônica com fração molar de 0,6 do comonômero iônico foi otimizada através de planejamento fatorial experimental, variando-se os principais fatores de processo: concentração do pacote de surfactante para formação da emulsão inversa, tempo de micronização, concentração de VISCOPLEX® e concentração de ácido graxo. Com base nos resultados obtidos a partir do primeiro planejamento, foram estudadas as seguintes variáveis: HLB do sistema de surfactantes e a troca dos surfactantes monoméricos por surfactantes poliméricos. A otimização da formulação levou em conta principalmente o custo-benefício para produção e comercialização em escala industrial. O fator micronização foi elevado em seu máximo e os fatores VISCOPLEX® e ácido graxo foram excluídos da formulação, após conclusão dos estudos. A troca dos surfactantes monoméricos por poliméricos foi vantajosa devido ao ganho de qualidade do produto final, mesmo com maior custo de implementação. Para minimizar os custos de formulação o fator HLB foi utilizado em seu máximo, onde houve incremento do ALKONAT® L 50 para formação da emulsão inversa. / Acrylamide based hydrosoluble polymers and copolymers and their derivatives are synthesized and mainly applied as flocculants, assisting removal of fine solids present in wastewater and industrial wastewater. Polyacrylamides may be present in their neutral form or with different ionic charges (positive or negative) in their composition depending on the type of specific application. Polyacrylamides are synthesized, mostly by inverse emulsions using radical polymerization, aiming polymers with high molecular weight. Cationic polyacrylamide formulation with 0.6 mole fraction of the ionic comonomer was optimized through design of experiments (DOE), varying the major process factors: surfactant package concentration to form inverse emulsion, micronization time, VISCOPLEX® concentration and fatty acid concentration. Based on the responses from the first DOE, a second DOE was performed, where the variables surfactant system HLB and the exchange of monomeric surfactant by polymeric surfactants were investigated. The formulation optimization considered mainly cost-effective production and industrial scale. The micronization factor was set at its maximum and VISCOPLEX® and fatty acid factors were excluded from the formulation, after conclusion of studies. Exchanging monomeric surfactants by polymeric surfactants led to a final product with higher quality, even considering a higher implementation cost. In order to minimize formulation costs HLB factor was used at its maximum, increasing the content of ALKONAT® L50 to form the inverse emulsion.

Des photoamorceurs construits sur une chimie radicalaire originale sont développés. Les photopolymères présentent des avantages écologiques (pas de COV) et économiques. Ils sont utilisés dans les adhésifs, les encres, les revêtements, l’optique… Une première étude est réalisée sur la photopolymérisation radicalaire (FRP) en présence d’organoboranes. Sous l’action de la lumière, des radicaux boryles sont formés. Ces composés convertissent des radicaux peroxyle (stables) en radicaux boryles très réactifs sous air. Ils permettent ainsi une polymérisation radicalaire en milieu aéré. Avec l’ajout de colorant, la photopolymérisation a lieu sous lumière visible.Une seconde étude est menée sur la photopolymérisation cationique (FRPCP). Des sources d’irradiation douces (lampe halogène, LED,…), peu énergivores et peu coûteuses sont employées. Des composés photosensibles ayant de fortes propriétés d’absorption dans le visible sensibilisent les sels d’iodonium. Cette décomposition permet d’amorcer la polymérisation cationique sous faible intensité lumineuse.Enfin, la polymérisation radicalaire contrôlée/vivante induite par de la lumière UV et visible est présentée. Deux modes de polymérisation contrôlée sont discutés : la NMP2 (Nitroxide Mediated PhotoPolymerization) et l’ATRP2 (Atom Transfer Radical PhotoPolymerization). En NMP2, les alcoxyamines ont la particularité de se réactiver sous irradiation lumineuse. En ATRP2, de nouveaux complexes d’iridium et de fer ayant de bonnes propriétés d’absorption dans le visible sont employés comme photocatalyseurs. Les résultats montrent un caractère contrôlé/vivant lors de la photopolymérisation du MMA. / Photoinitiators constructed on an original radical chemistry are developed. Photopolymers have ecological advantages (no VOCs) and economic. They are used in adhesives, inks, coatings, optical...A first study is carried out on the radical curing (FRP) in the presence of boron molecules. Under light irradiation, boryls radicals are formed. These compounds convert peroxyl radicals (stable) in boryls radicals highly reactive under air. They allow a radical polymerization in aerated medium. With the addition of dye, the photopolymerization is carried out under visible light.A second study was conducted on the cationic curing (FRPCP). Soft radiation sources (halogen lamp, LED, ...), energy efficient and inexpensive are used. Photosensitive compounds having high absorption properties in the visible sensitize iodonium salts. This decomposition allows initiating the cationic polymerization under low light intensity.Finally, controlled/living radical polymerization induced by UV and visible light is presented. Two controlled polymerization methods are discussed: NMP2 (Nitroxide Mediated Photopolymerization) and ATRP2 (Atom Transfer Radical Photopolymerization). In NMP2, alkoxyamines have the particularity to be reactivated under light irradiation. In ATRP2, new iridium complexes and iron having good absorption properties in the visible range are used as photocatalysts. The results show a controlled/living character during the photopolymerization of MMA.

<p>The eosinophil cationic protein (ECP) is usually associated with the eosinophil granulocyte. In this thesis the presence and production of this protein has been studied in two other cells. The circulating monocyte was found to contain ECP mRNA and small amounts of ECP, one thousand times less than that found in the eosinophil. The production decreased by differentiation of the myelomonoblastic cell line U937 into a macrophage phenotype. Submucosal lung macrophages did not stain for ECP and alveolar macrophages did not contain ECP mRNA. The circulating neutrophil contains ECP at a level hundred fold less than the eosinophil. We found that the protein is located to the primary granules of the neutrophil but could detect no ECP mRNA in the cell. It was shown in vitro that the protein was taken up by the cell and partly transported to the primary granules. The uptake did not seem to be receptor mediated. Upon stimulation of the neutrophils, ECP previously taken up, was re-secreted. </p><p>The ECP protein is heterogeneous both to molecular characteristics and to function. To evaluate if a genetic component is involved, the ECP gene was analysed in 70 individuals. Three single nucleotide polymorphisms (SNP´s) were found, denoted 277(C>T), 434(G>C) and 562(G>C). The two first were located to the mature peptide-coding region and would change the amino acids, arg45cys and arg97thr. The prevalence of the most common SNP, 434, was evaluated in two eosinophil-related diseases, allergy/asthma and Hodgkin Lymphoma (HL). Forty-three HL patients were evaluated and it was found that the 434GG was significantly more prevalent in patients having nodular sclerosis (NS) as compared to other histologies (p=0.03). Erythrocyte sedimentation rate was also related to the 434GG genotype (p=0.009). In 209 medical students 434GG was more common (p=0.002) in those who indicated allergy. The genotype was unrelated to the production of IgE antibodies to allergens. In analysis of 76 subjects with asthma it was found that the 434GG genotype was significantly more common among allergic asthmatics (p=0.04). Asthma and HL-NS are characterized by fibrosis and eosinophils and ECP has been suggested in fibrosis development. </p>

<p>Otitis media with effusion (OME) is the major form of chronic relapsing inflammatory disease of the middle ear, constitutes the most common diagnosis for children under 15 years old and is the major cause of auditory dysfunction in pre-school children. OME is a disease more commonly found in allergic children. These studies sought to investigate the inflammatory response in the middle ear of patients and test the hypothesis that an allergic-like response might occur in the ear. Atopy was diagnosed by standard in vitro tests. Immunochemical techniques used to study classic allergic rhinitis and asthma were extrapolated to the evaluation of OME children whose effusion persisted beyond 2 months. Not only eosinophil cationic protein (ECP), tryptase, CD3-positive and IL-5 producing cells, but also myeloperoxidase (MPO) was found in middle ear fluid and/or mucosa in the majority of patients with OME and atopy. </p><p>Initially, levels of ECP, MPO, and tryptase were measured in effusions from 97 random OME patients whose atopic status was determined by in vitro testing to 12 inhalants and 5 foods. The response of eosinophils, neutrophils and mast cells in the middle ear was distinctly different between atopic and non-atopic patients (p<0.001) with higher levels of the cell markers in the atopic group of patients. This suggested that 1) perhaps OME was predominantly a disease of atopics and that 2) they differed in their response from non-atopics.</p><p>Tryptase was measured in middle ear effusions from 38 patients with OME, 94.7% of whom were atopic by in vitro testing. Tryptase was elevated only in the effusion of atopic patients as compared to 5 controls (p<0.01). Biopsies stained histochemically for tryptase showed evidence of mast cells in the mucosa and submucosa from 6 of 8 OME ears but absent in 4 normals.</p><p>Middle ear biopsies, embedded in a plastic resin to improve the structural preservation, from 5 patients with OME and 5 normals were evaluated for the presence of eosinophils and neutrophils with monoclonal antibodies against 4 specific granule proteins. Eosinophils and neutrophils were present in the mucosa and mucus in significantly higher numbers than in the control group.</p><p>In an effort to determine whether the middle ear itself might be involved in allergic disease, evidence that some of the cells, mediators and cytokines associated specifically with a Th-2 response were sought for in the middle ear mucosa of these children. Middle ear biopsies from 7 atopic patients with OME and 4 controls demonstrated the presence of activated eosinophils, CD-3+ T cells and IL-5 mRNA cells only in the mucosa from atopic OME children. </p><p>Conclusion: Effusion and mucosal biopsies containing ECP, tryptase, and/or IL-5 mRNA cells, CD3+ T cells, eosinophils, and mast cells indicate that many of the mediators and cells essential to the production of a Th-2 immune mediated response are present in ears with chronic effusion. The increased levels of MPO in atopic patients further suggest that the general inflammatory response to putative inciting agents such as bacterial and viral products may be altered in atopy. These studies support the hypothesis that the exaggerated inflammation within the middle ear associated with most cases of OME is possibly the result of an atopic response within the middle ear itself.</p>