Orientadores: Claudia Herrera Tambeli, Maria Cecilia F. A. Veiga / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-06T06:07:18Z (GMT). No. of bitstreams: 1 Rodrigues_LucianeLacerdaFrancoRocha_D.pdf: 2035730 bytes, checksum: 6401d3a12bda71532a90f1fa6da06785 (MD5) Previous issue date: 2006 / Resumo: Considerando que a ATM recebe uma rica inervação simpática, o objetivo deste estudo foi investigar o papel das aminas simpatomiméticas na hiperalgesia da ATM induzida pela carragenina, além de validar a natureza inflamatória do modelo de hiperalgesia quimicamente induzida pela carragenina na ATM de ratos. Uma pequena dose de 5-hydroxytriptamina (5-HT; 75mg) que induz resposta comportamental nociceptiva mínima, foi aplicada na região da ATM de ratos 1h após a injeção de carragenina (C; 100mg) para detectar a sensibilização induzida pela carragenina na região da ATM, que foi avaliada pela soma das respostas nociceptivas comportamentais, como coçar a região orofacial e levantar a cabeça. O bloqueio da síntese de prostaglandinas pela indometacina sistêmica (2,5mg/kg) ou local (10µg) antes do início da inflamação pela carragenina diminuiu significativamente a hiperalgesia da ATM. A depleção das aminas simpatomiméticas pela guanetidina (30mg/kg por três dias consecutivos antes da injeção de carragenina na ATM) ou a co-aplicação de antagonistas dos adrenoceptores ß (propranolol nas doses de 0,25 e 2,25µg), assim como os antagonistas dos adrenoceptores ß2 (ICI 118,551 nas doses de 0,05 e 0,1 µg) com carragenina (C; 100 µg) reduziram significativamente a hiperalgesia na ATM. A co-aplicação de antagonistas dos adrenoceptores ß1 (atenolol nas doses de 6, 18, 54 ou 162µg) não afetou as respostas comportamentais induzidas pela carragenina (C; 100µg). Indometacina local, propranolol e ICI 118,551 não tiveram efeito quando injetados na ATM contra lateral, o que indica uma participação periférica das prostaglandinas e das aminas simpatomiméticas nesta hiperalgesia. Estes resultados sugerem que as aminas simpatomiméticas são liberadas no local da injúria onde as mesmas contribuem para a hiperalgesia inflamatória na ATM através dos adrenoceptores ß2, indicando que os mesmos são possíveis alvos para o desenvolvimento de novas drogas analgésicas no controle da dor da ATM / Abstract: The aim of this study was to further validate our carrageenan-induced temporomandibular joint (TMJ) inflammatory hyperalgesia model in rats by showing that administration of indomethacin before the initiation of inflammation would diminish the TMJ hyperalgesia. By using this model, it was investigated whether norepinephrine and local adrenoceptors contribute to the development of inflammatory TMJ hyperalgesia. Carrageenan-induced TMJ hyperalgesia was assessed by measuring the behavioral nociceptive responses, such as rubbing the orofacial region and flinching the head, induced by the injection of a low dose of 5-hydroxytryptamine into the TMJ sensitized one hour before by a TMJ injection of carrageenan. Blockade of prostaglandin synthesis by indomethacin prior to initiation of inflammation by carrageenan significantly attenuated the TMJ hyperalgesia. The guanethidine depletion of norepinephrine or the blockade of ß2 but not the blockade of the ß1 adrenoceptor by the selective adrenoceptor antagonists ICI 118.551 and atenolol, respectively, significantly reduced carrageenan-induced TMJ hyperalgesia. In this study, we further validate our carrageenan-induced TMJ hyperalgesia model to study the mechanisms involved in inflammatory TMJ hyperalgesia and to test the analgesic effect of different types of peripheral analgesics. By using this model, we show that norepinephrine is released at the site of injury where it contributes to the development of the inflammatory TMJ hyperalgesia. It is proposed that the contribution of norepinephrine to the development of the inflammatory TMJ hyperalgesia is mediated by the activation of ß2-adrenoceptors. Perspective: The findings that local sympathomimetic amines contribute to the inflammatory TMJ hyperalgesia by acting on ß2-adrenoceptors may be relevant to clinical TMJ inflammatory pain states less sensitive to non-steroidal anti-inflammatory drugs / Doutorado / Fisiologia Oral / Doutor em Odontologia

A literatura relata que o veneno de Crotalus durissus terrificus (VCdt) ou suas toxinas isoladas modulam a resposta inflamatória. A crotoxina (CTX) é a principal toxina do VCdt, representando aproximadamente 65% do conteúdo do veneno bruto. Dando continuidade aos estudos que evidenciam o efeito modulador do VCdt sobre a inflamação, foi demonstrado que o VCdt apresenta um efeito anti-inflamatório prolongado sobre a resposta inflamatória induzida pela carragenina (Cg), em camundongos. Esse estudo mostrou que uma única dose de VCdt, administrada pela via subcutânea, 7 ou 21 dias antes da injeção de Cg inibe, respectivamente, o desenvolvimento do edema de pata e a migração celular para a cavidade peritoneal, induzidos por este agente inflamatório. Este efeito anti-inflamatório também foi observado após a instalação da resposta inflamatória (Nunes et al., 2007). Além disso, foi demonstrado também que a CTX, é a toxina responsável por este efeito anti-inflamatório prolongado. Ainda, dados recentes mostram que os receptores para peptídeo formil, tais como lipoxina/anexina, mediadores com potente ação anti-inflamatória, estão envolvidos no efeito da CTX. Em continuidade a essa linha de investigação, este trabalho teve por objetivo caracterizar o efeito da CTX sobre a expressão de mediadores pró-inflamatórios e de moléculas de adesão envolvidas na resposta inflamatória induzida pela Cg. em camundongos. Além de avaliar também o efeito desta toxina sobre a translocação da subunidade p65 do NF-κB para o núcleo celular. Para tanto, foi, investigado o efeito de uma única dose de CTX (44 μg/kg) sobre: a expressão de P-selectina, ICAM-1, PECAM-1 e Mac-1; sobre a secreção de TNF-α, IL-1β, IL-6, PGE2, e LTB4 e sobre a expressão de iNOS e p65. Cabe destacar ainda que, um inibidor da síntese de glicocorticoides (Mifepristone), bem como um antagonista de receptor para glicocorticoides (Metirapona) foram administrados antes do tratamento da CTX, para avaliar também a participação de glicocorticoides endógenos no efeito anti-inflamatório da CTX. A administração subcutânea de uma única dose de CTX produziu: 1- diminuição da secreção de TNF-α, IL-1β, IL-6; 2- diminuição da expressão de P-selectina e ICAM-1 e 3- diminuição da expressão de p65. Por outro lado, a CTX não alterou os níveis de PGE2, e LTB4, como também não alterou a expressão de iNOS e Mac-1. Além disso, nossos resultados sugerem que os glicocorticóides endógenos não interferem no efeito anti-inflamatório da CTX, uma vez que o pré-tratamento com Mifepristone ou Metirapona não alteraram o efeito inibitório desta toxina sobre a migração celular. Em conjunto, os resultados caracterizam o efeito anti-inflamatório da CTX sobre a migração celular induzida pela Cg e sugerem que esta toxina pode inibir a expressão de importantes substâncias pró-inflamatórias envolvidas na resposta inflamatória pela Cg ao inibir a ativação do fator de transcrição, NF-κB, uma vez que este fator favorece a transcrição de vários genes, cujas proteínas são importantes no desenvolvimento da resposta inflamatória. Esses resultados contribuem para a elucidação dos mecanismos envolvidos na ação modulatória da CTX sobre a resposta inflamatória / The literature shows that Crotalus durissus terrificus snake venom (CdtV) or their toxins isolated modulate the inflammatory response. The crotoxin (CTX) is the main toxin of CdtV, representing approximately 65% of the content of the crude venom. It was demonstrated that CdtV presents a long-lasting anti-inflammatory effect induced by carrageenan (Cg) in mice. This study showed that a single dose of CdtV inhibits respectively, the development of paw edema and cell migration to the peritoneal cavity induced by this inflammatory agent. This anti-inflammatory effect was also observed after installation of the inflammatory response (Nunes et al., 2007). Furthermore, it was also demonstrated that CTX is responsible for this long-lasting anti-inflammatory effect. Still, recent data show that the formil peptide receptors, such as lipoxin/anexin, mediators with potent anti-inflammatory action, are involved in the effect of CTX. The aim of this study is characterize the effect of CTX on the expression of proinflammatory mediators and adhesion molecules involved in the inflammatory response induced by Cg in mice and also evaluate the effect of the toxin on translocation of the p65 subunit of NF-κB to the nucleus. Therefore, it was investigated the effect of a single dose of CTX (44 μg/kg) on: P-selectin, ICAM-1, PECAM-1 and Mac-1 expression; TNF-α, IL-1β, IL-6, PGE2 and LTB4 secretion and, on iNOS and p65 expression. It should be noted that a synthesis of glucocorticoids inhibitor (Mifepristone) and a glucocorticoid antagonist receptor (Metyrapone) were administrated before CTX treatment to evaluate the involvement of endogenous glucocorticoids in the anti-inflammatory effect of CTX. Our results show that a single dose of CTX produced: reduction of TNF-α, IL-1β and IL-6 secretion; reduction of P-selectin and ICAM-1 expression and reduction of p65 expression. Moreover, CTX did not alter levels of PGE2 and LTB4 secretion and did not alter iNOS and Mac-1 expression. Furthermore, our results suggest that endogenous glucocorticoids do not interfere with anti-inflammatory effect of CTX, since that pre-treatment with Mifepristone and Metyrapone did not alter the inhibitory effect of this toxin on cell migration induced by Cg and suggest that this toxin can inhibit the expression of important proinflammatory substances involved in the inflammatory response induced by Cg to inhibit the NF-κB activation, since this factor promotes the transcription of several genes whose proteins are important in the development inflammatory response. These results contribute to the elucidation of the mechanisms involved in the modulatory action of CTX on the inflammatory response

Orientador: Rosiane Lopes da Cunha / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T15:44:48Z (GMT). No. of bitstreams: 1 Perrechil_FabianadeAssis_D.pdf: 11335528 bytes, checksum: 434b9b3fbcb285d59ca3a70da948903d (MD5) Previous issue date: 2012 / Resumo: A microencapsulação é uma técnica que vem sendo amplamente estudada para a proteção de compostos bioativos e controle de sua liberação. Neste contexto, o objetivo geral deste trabalho foi produzir micropartículas através da extrusão de emulsões estabilizadas por biopolímeros (caseinato de sódio e ?-carragena) em solução de cloreto de potássio para a encapsulação de compostos hidrofóbicos. Na primeira parte deste estudo, o processo de extrusão em um atomizador foi estudado através da produção de microgéis a partir de soluções aquosas de caseinato de sódio (Na-CN) e ?-carragena. Os efeitos da vazão de alimentação, vazão de ar comprimido no bico atomizador, viscosidade e tensão superficial das soluções foram avaliados experimentalmente e através da análise de parâmetros adimensionais. Os resultados mostraram que os menores microgéis foram obtidos com a menor vazão de alimentação, menor viscosidade da solução biopolimérica e maior vazão de ar comprimido. No entanto, a esfericidade dos microgéis foi principalmente influenciada pela tensão superficial das soluções. Na segunda etapa do trabalho, emulsões óleo-água (O/A) multicamadas estabilizadas por caseinato de sódio e ?-carragena foram estudadas com o intuito de determinar as condições de maior estabilidade em pH 7 e 3,5. Em pH 7, o fenômeno de floculação por depleção ocorreu em elevada concentração de ?-carragena, enquanto que em pH 3,5 foi observada a floculação por ponte (bridging flocculation) em menores concentrações de polissacarídeo. Emulsões estáveis foram produzidas na maior concentração de polissacarídeo (1% m/v) em ambos os valores de pH (7 e 3,5) devido ao aumento da viscosidade da fase contínua. Na terceira parte do estudo, microesferas com potencial para encapsulação de compostos hidrofóbicos foram produzidas a partir da gelificação iônica das emulsões multicamadas e avaliadas quanto à estabilidade em diferentes meios. As microesferas produzidas em pH 3,5 foram mais estáveis do que aquelas preparadas em pH 7, sendo que ambas foram altamente estáveis quando dispersas em soluções de cloreto de potássio com concentrações superiores a 0,75% (m/v). Na última etapa do trabalho foi avaliado um exemplo de aplicação das microesferas para encapsulação de triptofano. Nesta etapa, as propriedades reológicas de suspensões de microgéis também foram estudadas com o intuito de verificar a sua influência na textura dos produtos. A eficiência de encapsulação do triptofano nas microesferas foi baixa (~30%), o que pode ser explicado pelo elevado tamanho dos poros do gel que não impediu a difusão desse composto de baixa massa molecular. No entanto, a liberação do bioativo foi bastante baixa quando as micropartículas foram diluídas em solução aquosa. Além disso, suspensões de microesferas com menores diâmetros e formatos mais esféricos apresentaram pouca influência na textura, mostrando sua potencial aplicação em produtos contendo elevada quantidade de água / Abstract: Microencapsulation is a technique widely used for the protection of bioactive compounds and for controlling their release. In this context, the general purpose of this work was to produce microbeads through the extrusion of biopolymer-stabilized emulsions (sodium caseinate and ?-carrageenan) in a potassium chloride solution, aiming the encapsulation of hydrophobic compounds. In the first part of this work, the extrusion process was studied in an atomizer, producing microgels from aqueous solution of sodium caseinate (Na-CN) and ?-carrageenan. The effect of feed flow rate and compressed air flow rate in the atomizer nozzle, viscosity and surface tension of solutions were evaluated experimentally and through the analysis of dimensionless parameters. The results showed that smaller microgels were produced using lower feed flow rate, lower viscosity and higher compressed air flow rate. Nevertheless, the sphericity of microgels was mainly influenced by the surface tension of solutions. In the second step of this work, oil-in-water (O/W) multilayered emulsions stabilized by sodium caseinate and ?-carrageenan were studied in order to determine the conditions of higher stability at pH 7 and 3.5. At pH 7, depletion flocculation occurred at high ?-carrageenan concentrations, while at pH 3.5, bridging flocculation was observed at lower polysaccharide concentrations. Stable emulsions were produced in the highest polysaccharide concentration (1% w/v) in both pH values (7 and 3.5) due to the increase of viscosity of the continuous phase. In the third part of this study, microbeads potentially useful for encapsulation of hydrophobic compounds were produced by ionic gelation of multilayered emulsions and evaluated in relation to stability in different media. The microbeads produced at pH 3.5 were more stable than those prepared at pH 7 and both were highly stable when dispersed in solutions with more than 0.75% (w/v) potassium chloride. In the last step of this study, an example of microbead application for encapsulating tryptophan was evaluated. In this step, the rheological properties of suspensions of microgels were also studied in order to verify their influence on the texture of products. The encapsulation efficiency of tryptophan in the microbeads was low (~30%), which was attributed to the large pore size of the gel matrix that could not hinder the diffusion of this low molecular weight compound. However, the release of bioactive was very low when the particles were diluted in aqueous solution. Moreover, suspensions of microbeads with smaller diameters and more spherical shape showed little influence on the texture, exhibiting their potential application in products with high water content / Doutorado / Engenharia de Alimentos / Doutor em Engenharia de Alimentos

Orientador : Rosiane Lopes da Cunha / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T02:33:04Z (GMT). No. of bitstreams: 1 Takeuchi_KatiuchiaPereira_M.pdf: 1779769 bytes, checksum: 68792b5cd7f6aee9eaab0bdb1c4181d4 (MD5) Previous issue date: 2003 / Resumo: Neste trabalho, as interações entre as proteínas do leite-carragena-sacarose em meio aquoso foram estudadas em sistemas mantidos em pH 6,7 e submetidos a tratamento térmico de 70ºC por 30 minutos. Estas interações foram estudadas através da avaliação do comportamento reológico em cisalhamento sob regime oscilatório da mistura dos biopolímeros e sacarose, durante e após a gelificação. As propriedades mecânicas dos produtos gelificados foram analisadas em ensaios a altas deformações sob compressão uniaxial, possibilitando um estudo das características de rigidez e elasticidade dos géis formados. As propriedades reológicas foram fortemente influenciadas pela carragena, que mostrou interação com as proteínas do leite e favoreceu a característica elástica dos sistemas. O isolado protéico de soro (IPS) promoveu o fortalecimento da rede, enquanto que o caseinato de sódio pareceu diminuir a rigidez da rede do gel, pois beneficiou a característica viscosa dos sistemas. A sacarose favoreceu a interação do IPS com a carragena levando à formação de uma rede mais interconectada, portanto mais elástica e resistente à ruptura. As interações entre as proteínas do leite-carragena-sacarose também foram avaliadas através da medida do estado da água nestes sistemas por meio de calorimetria diferencial de varredura, com a determinação da fração de água livre e não-congelável e a temperatura de início de fusão. A quantidade de água não-congelável e a temperatura de início de fusão foram fortemente influenciadas pela sacarose, provavelmente pelo favorecimento de interações entre as proteínas e destas com a água. O tratamento térmico (70ºC por 30 min) permitiu a interação das proteínas do soro com as frações hidrofílicas da caseína e sua interação com a carragena. As interações que ocorreram entre as proteínas do leite após o tratamento térmico, relacionadas à agregação intermolecular ou intramolecular, foram analisadas através de eletroforese de gel de poliacrilamida. Essa análise permitiu verificar que as concentrações das proteínas presentes no sistema influenciam na quantidade das unidades livres em solução, possibilitando a interação delas com os outros componentes do sistema, como a água e a carragena / Abstract: Interactions among milk proteins-carrageenan-sucrose in aqueous medium were studied in systems at pH 6.7 and submitted to thermal treatment at 70ºC for 30 min. These interactions were studied by evaluation of rheological behavior under oscillatory and steady shear of biopolymers mixture and sucrose during and after gelation. The mechanical properties of gelified products were determined in studies under uniaxial compression at high deformations, allowing a study of the characteristics of rigidity and elasticity of formed gels. The rheological properties were strongly influenced by carrageenan, wich showed interactions with milk proteins and favored the elasticity characteristic of the systems. Whey protein isolate (WPI) favored the formation of a more strength network, while sodium caseinate seemed decrease the rigidity of the gel network, since improved the viscous characteristic of the systems. Sucrose enhanced the interaction between WPI and carrageenan causing the formation of a more elastic network and resistant to the rupture. The interactions among milk proteins-carrageenan-sucrose were evaluated by quantification of state of water in these systems using a differential scanning calorimetry, with determination of free and unfreezable water fractions and the melting temperature onset. The unfreezable water (UFW) and temperature onset were strongly influenced by sucrose, probably by the enhancement of interactions protein-protein and protein-water. The thermal treatment (70ºC for 30 min) supported the interactions between the whey protein with the hydrophilic fractions of casein and their interactions with carrageenan. The interactions between milk proteins after thermal treatment were analysed by polyacrylamide gel electrophoresis related to intermolecular and intramolecular aggregation. This analysis allowed to verify that the protein concentration of the system had an effect on the amount of the free units in solution, making possible the interactions of them with the other systems components, as water and carrageenan / Mestrado / Mestre em Engenharia de Alimentos

A major effort to develop anticancer drugs through both empiric screening and rational design of new compounds has been under way for over 30 years (Katzung, 2004). In recent years, research and development in the field of sitespecific drug therapy has progressed significantly. Safe and non-toxic formulations of cytotoxic drugs based on polymers with their improved sitespecific delivery and effective activation to biologically active cytotoxic compounds at the targeted tumours have become a promising approach to cancer therapy. Drug delivery systems based on polymer micelles, coated microand nanoparticles, liposomes and various pro-drug systems including watersoluble polymer–drug conjugates and immunoconjugates have been prepared and extensively studied as novel drug delivery systems designed for cancer chemotherapy. Amongst these drug delivery systems that enable specific drug delivery and release, water-soluble polymer–drug conjugates rank among the most promising, versatile and efficient systems. This dissertation reviews the preclinical testing and pharmacokinetic study of D85, a novel water-soluble macromolecular pro-drug that is a polymer with pHcontrolled methotrexate (MTX) release with potential for treatment of cancer in humans (Ulbrich&Subr, 2004). As MTX is also indicated in low doses for the treatment of chronic inflammatory conditions, the polymer was further tested in an acute inflammatory model to determine whether the polymer would be more effective than MTX in controlling inflammation. The objective of this study was to compare the potency and efficacy of D85 to MTX. D85, a MTX conjugated polymeric lead compound, was designed and synthesised as a potential anti-neoplastic and anti-inflammatory agent. It was initially tested in vitro on three different cancer cell lines where selective toxicity towards the cancer cell cultures compared to primary cell cultures and greater toxicity than MTX was observed. The initial in vitro tests showed very promising results with D85 demonstrating approximately 300 times greater cytotoxicity than MTX against a colon cancer cell line (COLO 320 DM). This high cytotoxic effect warranted further investigation in an in vivo colon cancer tumour model. An induced murine tumour model of COLO 320 DM was successfully developed in nude mice, and the anti-tumour efficacy of D85 tested in this model. The maximum tolerated dose of D85 was established by carrying out an in vivo dose ranging toxicity test in BALB/c mice. The anti-inflammatory effects of D85 were also determined using the carrageenan-induced paw oedema model in rats where carrageenan was injected into a footpad of a rat causing acute oedema, which was measured using a water displacement plethysmometer. D85 was found to exacerbate the inflammatory response. Finally, the pharmacokinetic parameters of MTX and D85 were assessed using a LC/MS/MS method specifically developed and validated to determine low concentrations of MTX in small volumes of plasma. This new method made use of online solid phase extraction and sample cleanup on 2μl injections of diluted plasma allowing an entire pharmacokinetics study to be completed on an individual rat. Fairly similar pharmacokinetics were determined from both compounds. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Pharmacology / unrestricted

Les protéines et les polysaccharides constituent avec les lipides les principaux ingrédients de l’alimentation et lui confèrent à la fois ses propriétés de nutrition et de texture. Une tendance actuelle de l’industrie agroalimentaire est d’élaborer des aliments plus sains c'est-à-dire moins gras et moins salés. A ce titre, les polysaccharides sont des agents detexturation efficaces lorsqu’ils sont utilisés seuls ou en combinaison avec des protéines. Le développement de nouveaux produits alimentaires nécessite donc de rationaliser et mieux comprendre les propriétés physico-chimiques des solutions et des gels mixtes à base de protéines et de polysaccharides. Au cours de ce travail de thèse, nous avons étudié des mélanges de protéines globulaires (la β-lactoglobuline: β-lac) et de polysaccharide (le κ-carraghénane: κ-carr). Ce dernier provient d’algues et, en solution, il conduit à des gels au dessous d’une température critique qui dépend de la nature du sel ajouté. Le κ-carr est un additif important dans l’industrie alimentaire et plus particulièrement comme texturants des produits laitiers. Il est donc essentiel de comprendre les interactions qu’il développe avec les protéines du lait comme la β-lac.L’objectif de ce travail est d’étudier la structure et les propriétés mécaniques d’agrégats ou de gels de β-lac mélangés avec du κ-carr et d’étudier leur influence sur la gélification de ce dernier. Nous nous sommes plus particulièrement intéressés à la sensibilité des mélanges aux ions calcium. Des agrégats protéiques ont été formés soit indépendamment puis mélangés au κ-carr soit directement in situ en dénaturant thermiquement des mélanges κ-carr/β-lac native. Les deuxméthodes de préparation ont été comparées pour des compositions constantes des mélanges. La diffusion de la lumière, la rhéologie et la microscopie laser confocale ont été mises en oeuvre pour étudier la texture des mélanges.La taille et la morphologie des agrégats protéiques dépendent fortement de la concentration en ions calcium ajoutés qui se lient spécifiquement aux protéines. Nous avons montré que les très grands agrégats protéiques formés en présence de calcium conduisent à une microséparation de phase quand ils sont mélangés avec du κ-carr même à très faible concentration. Ainsi, la structure des systèmes mixtes est très sensible à la quantité de calcium en présence. Lesagrégats protéiques renforcent les gels de κ-carr formés en présence de potassium tout comme l’ajout de calcium. Ce renforcement dans le cas des agrégats protéiques est dû au transfert des ions calcium de la β-lac vers le κ-carr. De plus, nous avons montré que la gélification du β-carr induite par des ions potassium continuait à avoir lieu en refroidissantdes mélanges κ-carr/β-lac où cette dernière est dénaturée in situ. Cela conduit à des réseaux interpénétrés qui sont plus forts mécaniquement que la somme des deux réseaux pris individuellement. En conclusion, nous avons montré que la compétition entre la β-lac et le κ-carr pour les ions calcium était le paramètre de contrôle des propriétés texturales desgels mixtes. / Protein and polysaccharide are together with lipids the main ingredients of food and procure both nutrition and texture. A recent tendency in the food industry is to develop more healthy products that contain less fat and salt. The addition of polysaccharides is recognized as a good way to control the texture of food products. The texture of many food products is determined by gelation of either the proteins or the polysaccharides, or both. When both are present, gelation of the protein or the polysaccharide will be influenced by the presence of the other type. Understanding of the physical chemical properties of aqueous solutions and gels containing protein and polysaccharides by themselves and in mixtures is needed for a rational development of novel food products. This thesis describes an investigation of mixtures of the globular protein β-lactoglobulin (β-lg) and the polysaccharide κ-carrageenan (κ-car). κ-car is a polysaccharide isolated from algae that is often used as an additive in food industry. In solution it forms a gel below a critical temperature that depends on the amount and the type of salt. Addition of κ-car can improve the smoothness, creaminess, and body of food products and is often usedmodify the texture of dairy products. Therefore it is important to understand the interaction of κ-car with milk proteins such as β-lg, which is the main protein component of whey. The objective of the present investigation was to study the structure andthe mechanical properties of β-lg aggregates or gels when mixed with κ-car and to study the influence of the former on the gelation of κ-car. The focus was on the sensitivity of the system to calcium ions Protein particles were either formed separately and subsequently mixed with κ-car or formed directly in mixtures of κ-car and native β-lg by heating. The two different methods of preparation were compared with the same composition of polymers. The research presented in this thesis is essentially experimental using scattering techniques and confocal laser scanning microscopy to study the structure and shear rheology to study the dynamic mechanical properties.The size and morphology of protein aggregates formed by heating β-lg is strongly dependent on the concentration of Ca2+ that binds specifically to the proteins. It is shown that larger aggregates formed in the presence of Ca2+ micro-phase separate already at low κ-car concentrations. Therefore the structure of mixed systems is extremely sensitive to the amount of Ca2+ present in the system. The presence of protein aggregates was found to reinforce potassium induced κ-car gels, but it was also found that addition of CaCl2 strengthens potassium induced pure κ-car gels. We show that the reinforcement by addition of protein aggregates is caused by the transfer of a fraction of Ca2+ from β-lg to κ-car. It was shown that potassium induced gelation of κ-car also occurs during cooling heat-set β-lg gels formed in mixtures at higher protein concentrations leading to interpenetrated networks that are stronger than the sum of the individual networks. Themain conclusion of the investigation reported here is that the competition of κ-car and β-lg for calcium ions determines both the structure and the mechanical properties of the mixed systems.

La chimie se doit de développer de nouveaux axes de recherche à la fois respectueux de la nature et s’inscrivant dans une démarche globale éco-compatible. Dans ce contexte, l’utilisation des polymères naturels, notamment les polysaccharides, permet de synthétiser des matériaux innovants des applications dans de nombreux secteurs industriels. L’objectif de ce travail est de valoriser les polysaccharides marins tels que le chitosane et le κ-carraghénane à travers l’exploration de deux axes de recherches. Le premier axe est consacré à l’amélioration des propriétés mécaniques, électriques et de sorption de biopolymères par l’incorporation de graphène. Un protocole original a permis de disperser très efficacement du graphène au sein du chitosane pour la conception de films et d’aérogels nanocomposites. L’analyse des films a mis en évidence une amélioration simultanée de la rigidité, de la résistance, et de l’élongation à rupture, pour de faibles teneurs en graphène. Le seuil de percolation permettant l’obtention d’une conductivité électrique n’a pas été atteint aux faibles taux de charges utilisés. L’étude des aérogels chitosane/graphène a, quant à elle, révélé que l’incorporation de graphène aux aérogels de chitosane permettait d’augmenter leur capacité d’adsorption de colorants.Le deuxième axe concerne l’introduction d’hétéroatomes dans la structure carbonée du graphène. Pour obtenir du graphène dopé en azote et en soufre, des aérogels de polysaccharides marins ont été synthétisés, puis pyrolysés dans des conditions contrôlées. Les aérogels carbonés obtenus sont ensuite exfoliés dans l’eau par l’utilisation d’ultrasons. Les groupements amine du chitosane ont permis d’obtenir avec un haut rendement un graphène dopé avec un taux de 5 % d’azote. De plus, il a été possible de moduler de 5 % à 11 %ce taux d’azote par l’emploi de liquide ionique tel que le [EMIm][dca]. De façon similaire, les groupements sulfate du κ-carraghénane ont permis de doper du graphène en soufre avec un taux d’atomes de soufre de 1,5 %. / The chemistry have to develop new research axis both respectful of the nature and joining an eco-compatible global approach. In this context, use natural polysaccharides allow to synthesize innovative materials for applications in many industries fields. The aim of this work is add value to the marine polysaccharide such as chitosan and κ-carrageenan through two research axis.The first axis is consecrated to increase the mechanical, electrical and color sorption properties by introduce graphene filler in biopolymer matrice. An easy and original protocol allowed scattering very effectively graphene in chitosan to design films and aerogels nanocomposites. The analyse of nanocomposite films show an improvement of stiffness, tensile strength and elongation break at the same time with low content of graphene. However, the percolation threshold was not reach to bring electrics properties in films. The study of chitosan/graphene aerogel reveals that graphene allows an increase of color agent adsorbing power such as eosin Y compared with aerogels chitosan.The second axis concerns the introduction of heteroatom in graphene carbon structure. To obtain nitrogen-doped graphene and sulphur-doped graphene, it requires the synthesis of marine polysaccharide aerogel, and their pyrolysis under controlled conditions. The carbon aerogels are exfoliated in water with sonification. Amine groups in chitosan allowed through this process a nitrogen-doped graphene with high yield and nitrogen rate of 5 %. Moreover, it was possible to modulate nitrogen rate with ionic liquid such as [EMIm][dca]. So the nitrogen atom rate increases from 5% to 11%. In similar way, sulfate group in κ-carrageenan gives sulphur-doped graphene with sulphur rate of 1,5%.

Philosophiae Doctor - PhD / Growth rates of three commercial eucheumoids: brown Eucheuma denticulatum and green and brown Kappaphycus alvarezii were studied at three sites (Gazi Bay, Kibuyuni and Mkwiro) in southern Kenya. The study was conducted using the fixed off-bottom rope technique over a 15 month period from August 2001 to October 2002, in 4 plots (5 m x 1.5 m) set up at each site. The brown E. denticulatum had the highest mean growth rate over the entire period of 4.7% day-I compared to the green and brown K. alvarezii which were 4.3% day l and 4.2% dayl, respectively. Mean relative growth rates were highest at Gazi (5.6% dayl), and lowest in Kibuyuni (3.2% day-I) with intermediate values of 4.8% dail at Mkwiro. Increased water motion was observed to increase thallus nitrogen and hence the growth of eucheumoids. The 'ice-ice' syndrome affected both brown E. denticulatum and brown K. alvarezii but not green K. alvarezii. Mean growth was higher during the southeast monsoon (4.7% day+) than during the northeast monsoon (4.0% dayl).The carrageenan characteristics of the three morphotypes were measured for 12 months. The highest carrageenan yield was obtained for green K. alvarezii (59.1% dry wt), whereas the average carrageenan yield for brown K. alvarezii was 56.5% dry wt and 56.6% dry wt for brown E. denticulatum. The plants at Gazi (58.0% dry wt) had a slightly, though significantly, higher carrageenan yield than both those at Kibuyuni (57.1 % dry wt) and Mkwiro (57.3% dry wt). However, from a commercial point of view the differences in carrageenan yields were not meaningful. Highest gel strengths were obtained in carrageenans from green K. alvarezii (1042.1 g cm") and brown K. alvarezii (1053.7 g ern"), whereas low values of 100.8 g ern" were obtained for brown E. denticulatum. The brown E. denticulatum had carrageenan with higher viscosity (81.7 mPa.s) and sulphate content (29.1% dry wt) than both green and brown K. alvarezii. The gel viscosities of all the morphotypes were higher during the southeast monsoon (67.3 mPa.s) than during the northeast monsoon (46.3 mPa.s) and were positively correlated with gel strengths.A survey was conducted among households in the three villages, from April to September 2001 to assess their socio-economic characteristics. There were 182 household heads interviewed; about 20% were women. Fishing was the main source of livelihood for about 48% of the household members. In 2001, the average monthly income for the surveyed households was Kshs. 9904 (1 US$=75 Kshs.), with about 67% having less than Kshs. 10 000. The average prevalence of poverty among the households surveyed was 45.1% with 38.8%,54.8% and 46.7% of households in Gazi, Kibuyuni and Mkwiro villages, respectively, living below the poverty line of Kshs. 1239 per month per adult person. An economic feasibility study for growing brown E. denticulatum and brown K. alvarezii in pilot farms of 0.1 ha was conducted at Gazi and Kibuyuni. A higher yield of 793 kg dry wt was obtained for plants grown at Gazi than those at Kibuyuni (793 kg dry wt). The net income derived from E. denticulatum was estimated at Kshs. 7549 annually in a 0.1 ha seaweed farm. A higher annual income of Kshs. 49 126 was generated from K. alvarezii. The rate of return on investment in farming E. denticulatum ranged from 15 to 63%, while 122 to 380% for K. alvarezii. The pay back period was shorter for the latter (0.3 to 0.7 years) than the former (1.2 to 2.7 years).A cross-sectoral policy analysis regarding legislation and policy relevant to the introduction and development of eucheumoid cultivation in Kenya, with particular reference to Kenyan legislation was conducted. The analysis showed that there is no system of promoting or regulating mariculture, though there are fragmented regulations that are scattered among the policies, Acts and regulations of various institutions. Such regulations were not designed specifically for mariculture and as a result they do not fully address the needs of mariculture. The establishment of a national mariculture development programme in Kenya is proposed as a means to develop and manage the farming of marine resources, including seaweeds.

O sulfeto de hidrogênio (H2S) é uma molécula produzida endogenamente que desempenha um importante papel em diversos processos fisiológicos e patológicos, incluindo inflamação e nocicepção. Assim, os objetivos deste estudo foram avaliar os efeitos de um doador de H2S de liberação lenta, o composto GYY-4137, na sinovite aguda induzida por carragenina (CGN) na articulação temporomandibular (ATM) de ratos, e caracterizar os mecanismos envolvidos. Os resultados mostraram que na sinovite aguda de ATM (caracterizada por alodinia mecânica e infiltração de leucócitos 4 h após a injeção i.art. de CGN), a administração concomitante do composto GYY-4137 resultou em redução destes parâmetros envolvendo a participação de GMPc e abertura de canais KATP, sem afetar a produção aumentada das citocinas IL-1β e IL-6. Estes achados dão suporte ao uso de doadores de H2S como potenciais alternativas terapêuticas para o tratamento de distúrbios temporomandibulares. / Hydrogen sulfide (H2S) is an endogenously produced molecule that plays an important role in many physiological and pathological processes, including inflammation and nociception. The objectives of this study were to evaluate the effects of slow-release H2S donor, compound GYY-4137, in the carrageenan (CGN) induced acute synovitis of the temporomandibular joint (TMJ) in rats, and to characterize the mechanisms involved. The results showed that in the acute TMJ synovitis (characterized by mechanical allodynia and leukocyte infiltration 4 h after the i.art CGN injection), the concomitant administration of compound GYY-4137 resulted in reduction of these parameters, involving the participation of cGMP and KATP opening, without affecting the increased production of the cytokines IL-1β and IL-6. These findings support the use of H2S donors as potential therapeutic alternatives for treatment of temporomandibular disorders.

Made available in DSpace on 2017-07-21T18:53:14Z (GMT). No. of bitstreams: 1 Ricardo Alexandre.pdf: 806029 bytes, checksum: 44b9b6a660261e24894a5080f79427ab (MD5) Previous issue date: 2006-02-16 / Para a redução de gorduras em produtos cárneos; além de utilização de cortes mais magros; é possível adicionar substituintes de gorduras; como amidos e gomas. Segundo a legislação brasileira; a adição de carragena em presunto é facultativa; contudo; não é permitida a adição de amido neste tipo de produto. Neste trabalho; utilizou-se um planejamento fatorial 2² com duplicata no ponto central; variando amido (0 a 2%) e carragena (0 a 1%) em presunto de peru. Tanto o amido quanto a carragena apresentaram efeitos negativos para perda por cozimento e para a perda por reaquecimento; indicando que a presença destes hidrocolóides favoreceu a permanência de água nos produtos. Contudo não houve diferenças significativas de pH; e na composição centesimal; tensão de cisalhamento e avaliação sensorial. Além disto; uma característica de sinergismo entre os polissacarídeos foi notada. Amostras elaboradas com 1% de carragena apresentaram formação do exsudado gelatinoso; mas as amostras que continham 1% de carragena e 2% de amido não apresentaram este defeito. O amido; portanto; reduz a formação de exsudado gelatinoso em presunto cozido de peru adicionado de carragena. A utilização de amido em presunto; melhorou algumas características físico-químicas; reduziu defeitos e não houve diferença sensorial quando comparado ao padrão brasileiro sem adição de amido.