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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Avaliação in vitro - in vivo de duas formulações de pantoprazol : estudos farmacocineticos e perfis de dissolução em meios biorelevantes / In vitro - in vivo evaluation of two pantoprazole formulations : pharmacokonetic studies and dissolution profiles in biorelevant media

Campos, Daniel Rossi de 12 April 2008 (has links)
Orientador: Jose Pedrazzoli Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-12T09:45:13Z (GMT). No. of bitstreams: 1 Campos_DanielRosside_D.pdf: 1666073 bytes, checksum: 1437407c543022990155fc5709053ecc (MD5) Previous issue date: 2008 / Resumo: O objetivo do presente estudo foi comparar o comportamento in vivo e in vitro de duas formulações de pantoprazol. Além disso, foi proposta a classificação biofarmacêutica provisional do fármaco, bem como uma correlação in vitro - in vivo não linear (IVIVR). Os estudos in vivo foram conduzidos em dose única em jejum (n=28) e pós-prandial (n=62) com desenho cruzado e randomizado. As concentrações plasmáticas de pantoprazol foram determinadas por LC-MS/MS. Os parâmetros farmacocinéticos e a deconvolução dos dados de concentração plasmática versus tempo foram obtidos empregando-se o programa WinNonlin 5.2 - IVIVC toolkit (Pharsight, EUA). Os perfis de dissolução foram avaliados em meios biorelevantes (FaSSIF e FeSSIF) nos aparatos USP 2 e 3 e as curvas de dissolução foram comparadas considerando os cálculos de f2 ou modelos dependentes. Os valores da solubilidade, Log P e cLog P do pantoprazol foram obtidos do Merck Index (Whitehouse Station, EUA) e do programa ChemDraw Ultra 10.0 (Cambridgesoft, EUA). Os dados de permeabilidade do pantoprazol forma obtidos do programa ADMET Predictor (Simulations Plus, EUA). A classificação biofarmacêutica provisional do pantoprazol foi proposta considerando o fármaco metoprolol como referência. A IVIVR foi estabelecida entre as frações dissolvidas (Fd), dos ensaios no aparato 2, com as frações absorvidas dos estudos in vivo. Para o estudo em jejum os valores dos intervalos de confiança 90% para os parâmetros Cmax (0.94-1.03) e ASC0-t (0.89-0.99) apresentaram-se dentro dos limites de confiança (0.8-1.25). Entretanto, os intervalos de confiança do estudo pós-prandial não se apresentaram dentro dos limites de confiança. Os perfis de dissolução nos aparatos USP 2 e 3 demonstraram a mesma disposição das formulações nos meios FaSSIF e FeSSIF, considerando o modelos de f2 e Weibull. Os valores de solubilidade, Log P e permeabilidade para o fármaco pantoprazol obtidos in silico permitiram a classificação do fármaco como de alta solubilidade e baixa permeabilidade. A IVIVR não linear obtida para as formulações de pantoprazol indicaram que a permeabilidade é fator limitante para a absorção. Enfim, os perfis de dissolução no meio biorelevante FaSSIF, nos aparatos USP 2 e 3, puderam ser empregados para prever o comportamento in vivo das formulações. O pantoprazol foi classificado como um fármaco classe III e a IVIVR não-linear obtida confirma a classificação biofarmacêutica provisional. Além disso, pôde-se sugerir a bioisenção para formulações de pantoprazol com base nos resultados dos estudos de dissolução em meios biorelevantes e na conhecida segurança e tolerabilidade desse fármaco. / Abstract: The purpose of the study was to compare the in vivo and in vitro behaviour of pantoprazole formulations. Moreover, a provisional biopharmaceutical classification of the drug (BCS) was proposed as well as a non-linear in vitro - in vivo relationship (IVIVR). The in vivo studies were conducted under single dose in fasting (n=28) and fed conditions (n=62) and randomized crossover design. Plasma concentrations of pantoprazole were determined by LC-MS/MS. Pharmacokinetic parameters and deconvolution data were calculated from the observed plasma-concentration time profiles by WinNonlin 5.2 - IVIVC toolkit (Pharsight, USA). Dissolution profiles were evaluated in biorelevant media (FaSSIF and FeSSIF) in USP apparatus 2 and 3 and the dissolution curves were compared to either f2 values or model-independent approach. The solubility, Log P and cLogP data of pantoprazole were obtained from Merck Index (Whitehouse Station, USA) and ChemDraw Ultra 10.0 (Cambridgesoft, USA). The permeability data of pantoprazole were calculated by ADMET Predictor (Simulations Plus, USA). The provisional biopharmaceutical classification of pantoprazole was proposed considering metoprolol as a reference drug. The IVIVR analysis was evaluated considering the dissolved drug fraction (Fd) from apparatus 2 and the absorved drug fraction (Fa) from the in vivo studies. Under fasting condition the 90% C.I for Cmax (0.94-1.03) and AUC0-t (0.89-0.99) were within the range of bioequivalence (0.8-1.25). However, the results of the fed study were not within the BE range. The dissolution profiles in USP apparatus 2 and 3 demonstrated a similar disposition of both formulations in FaSSIF and FeSSIF media considering f2 and Weibull's models. The solubility, Log P and permeability values of pantoprazole obtained by in silico evaluation allowed the classification of pantoprazole as a highly soluble and low permeability drug. The non-linear IVIVR obtained for the pantoprazole formulations indicated that absorption of pantoprazole is limited by permeability. In conclusion, the dissolution profiles in the biorelevant medium (FaSSIF) on both USP apparatus 2 and 3 may be used as a tool to predict the in vivo disposition of the formulations. Pantoprazole was classified as a class III drug (BCS) corroborated by the non-linear IVIVR study to support this provisional classification. Furthermore, biowaiver may be granted for pantoprazole formulations on the basis of in vitro dissolution results in biorelevant media and the data available in the literature concerning high tolerability and safety of the drug. / Doutorado / Doutor em Farmacologia
2

Preparação e caracterização físico-química de complexos de hidrolisados parciais de proteína com minerais / Preparation and Physical Chemistry characterization of mineral partial protein hydrolisates complexes

Franzan, Renata 09 October 2006 (has links)
Os minerais essenciais participam de várias funções vitais do organismo, suas deficiências contribuem de maneira significante para a morbidade e mortalidade na infância, especialmente nos países em desenvolvimento, sendo consideradas como problema de saúde pública em todo o mundo. Minerais apresentados na forma de complexos orgânicos têm sido propostos para correção destas deficiências por apresentarem maior biodisponibilidade, quando comparados aos equivalentes sais inorgânicos. Os minerais cobre, ferro, manganês e zinco são essenciais aos organismos vivos (humano e animal), a manutenção de seus níveis de acordo com as necessidade fisiológicas contribuem para a manutenção da saúde, resultando em benefícios econômicos. No presente trabalho foi realizada a preparação e caracterização físico-química de complexos dos minerais Cobre (Cu), Ferro (Fe), Manganês (Mn) e Zinco (Zn) com hidrolisados parciais de proteína de soja. As hidrólises utilizando as enzimas Aranzime e Alcalase foram mais eficientes que as demais hidrólises enzimáticas ou ácidas, entretanto somente a Alcalase foi aprovada para a manufatura de produtos alimentares de consumo humano. A coordenação entre os metais e o hidrolisado pode ser confirmada por pelo deslocamento das bandas ?NH2, ?aCOO- e ?sCOO-. Os complexos obtidos de cobre, ferro, manganês e zinco, posuem em sua composição os respectivos percentuais de ligação: 2,21%, 1,22%, 12,38% e 10,40%. / The essential minerals participate in many vital functions in the organism, its deficiencies contribute in significant way for the morbidity and mortality in the childhood, especially in developing countries, being considered as public health problem in the whole world. Minerals presented in the form of organics complexes have been considered a good choice for these deficiencies, because it presents greater bioavailability when compared with the equivalents inorganic salts. The minerals copper, iron, manganese and zinc are essential to the organisms (human and animal), its physiological levels in accordance with the necessity contribute for the health maintence, resulting in economical benefits. In the present work it was carried through preparation and physical and chemical characterization of mineral complexes of Copper (Cu), Iron (Fe), Manganese (Mn) and Zinc (Zn) with partial hydrolysates of soy protein. The hydrolyses using the Aranzime and Alcalase enzymes had been more efficient than other enzymatic or acid hydrolyses, however only the Alcalase enzyme is approved for the manufacture of alimentary products for human consumption. Coordination between metals and the hydrolysate can be confirmed by the displacement of the ?NH2, ?aCOO- and ?sCOO- bands. The gotten copper, iron, manganese and zinc complexes, had the respective percentages of metal in its composition: 2,21%, 1,22%, 12,38% e 10,40%.
3

Biodisponibilidade como parÃmetro de qualidade e sua importÃncia no registro de medicamentos / Biodisponibility as a quality pattern and its importance to the registration of medicines.

Roberta Meneses Marquez de Amorim 08 July 2004 (has links)
nÃo hà / Este trabalho aborda a biodisponibilidade dos fÃrmacos, os fatores que a alteram e sua importÃncia como parÃmetro de qualidade para o registro de medicamentos no Brasil. Preliminarmente por uma questÃo metodolÃgica serà apresentada uma abordagem sobre farmacocinÃtica onde serà conceituada e comentada a absorÃÃo de fÃrmacos e a biodisponibilidade. Com relaÃÃo aos fatores que alteram a biodisponibilidade, sÃo abordados aqueles relacionados ao paciente que abrange os fatores relacionados ao trato gastrintestinal, os relacionados ao sÃtio de absorÃÃo, os fatores genÃticos, peso corporal, idade, sexo e alteraÃÃes fisiolÃgicas provocadas por doenÃas. SÃo abordados ainda, os fatores relacionados ao fÃrmaco onde sÃo incluÃdos e comentados tÃpicos como estado fÃsico, polimorfismo, tamanho de partÃcula, estado de solvataÃÃo, caracterÃsticas de ionizaÃÃo, coeficiente de partiÃÃo, modificaÃÃes na forma quÃmica, formaÃÃo de complexo, quiralidade, inativaÃÃo antes da absorÃÃo, ligaÃÃo Ãs proteÃnas plasmÃticas e teciduais, seletividade no sÃtio de absorÃÃo. SÃo apresentados tambÃm, os fatores relacionados à formulaÃÃo onde sÃo discutidos o tipo de forma farmacÃutica, tamanho das partÃculas e Ãrea superficial, tipo e quantidade de excipientes, variÃveis do processo de fabricaÃÃo, velocidade de dissoluÃÃo do medicamento. Como suporte tÃcnico à apresentado o planejamento de um protocolo de estudo de biodisponibilidade, abordando itens com regime de dosagem, delineamento do estudo, sujeito da pesquisa, estudo piloto e doseamento, metodologia analÃtica, farmacocinÃtica e anÃlise estatÃstica. Por fim sÃo abordados os aspectos regulatÃrios sobre biodisponibilidade no Brasil incluindo os critÃrios de aceitaÃÃo para registro de medicamento de um estudo de biodisponibilidade. Diante da apresentaÃÃo e discussÃo dos fatores biofarmacotÃcnicos e fisiolÃgicos que interferem na biodisponibilidade do medicamento, objetiva-se subsidiar e justificar a necessidade dos estudos de biodisponibilidade comparativa para registro de medicamentos. / This work will discuss the bioavailability of drug, how it is changed and its importance as a quality pattern to the registration of medicines in Brazil. In this light, bioavailability will be previously conceptualized and discussed together with other topics relevant to the comprehension of this work. Bioavailability can be affected by both the patient conditions and the drug itself. In what regards the patient conditions, the important factors discussed here are gastrointestinal treatment, place of absorption, genetics factors, body weight, age, gender and physiological changes caused by illness. With regard to the drug, topics such as physical state, polymorphism, size of particle, state of solvability, characteristics of ionization, coefficient of partition, chemical alterations, complex formation, stereochemistry activity, inactivation before absorption, link to plasmatic and tissue proteins and selectivity in the place of absorption. Among the same lines, the formulation of medicines are also discussed, specially issues such as pharmaceuticsâ form, the size of particles, superficial area, type and quantity of excipients, variables of the manufacture process and the speed of dissolution of medicines. It is also presented a proposal of a protocol of study of bioavailability covering topics like dosing, outline of the study, the subject of the research, previous studies, analytical methodology, pharmacokinetic and statistics analysis. In the realm of regulation, considering the influence of biopharmacotecnic and physiological factors in the bioavailability of medicines, this work argues for the importance of previous submission of biodisponibility studies as a condition for the registration of medicines.
4

Preparação e caracterização físico-química de complexos de hidrolisados parciais de proteína com minerais / Preparation and Physical Chemistry characterization of mineral partial protein hydrolisates complexes

Renata Franzan 09 October 2006 (has links)
Os minerais essenciais participam de várias funções vitais do organismo, suas deficiências contribuem de maneira significante para a morbidade e mortalidade na infância, especialmente nos países em desenvolvimento, sendo consideradas como problema de saúde pública em todo o mundo. Minerais apresentados na forma de complexos orgânicos têm sido propostos para correção destas deficiências por apresentarem maior biodisponibilidade, quando comparados aos equivalentes sais inorgânicos. Os minerais cobre, ferro, manganês e zinco são essenciais aos organismos vivos (humano e animal), a manutenção de seus níveis de acordo com as necessidade fisiológicas contribuem para a manutenção da saúde, resultando em benefícios econômicos. No presente trabalho foi realizada a preparação e caracterização físico-química de complexos dos minerais Cobre (Cu), Ferro (Fe), Manganês (Mn) e Zinco (Zn) com hidrolisados parciais de proteína de soja. As hidrólises utilizando as enzimas Aranzime e Alcalase foram mais eficientes que as demais hidrólises enzimáticas ou ácidas, entretanto somente a Alcalase foi aprovada para a manufatura de produtos alimentares de consumo humano. A coordenação entre os metais e o hidrolisado pode ser confirmada por pelo deslocamento das bandas ?NH2, ?aCOO- e ?sCOO-. Os complexos obtidos de cobre, ferro, manganês e zinco, posuem em sua composição os respectivos percentuais de ligação: 2,21%, 1,22%, 12,38% e 10,40%. / The essential minerals participate in many vital functions in the organism, its deficiencies contribute in significant way for the morbidity and mortality in the childhood, especially in developing countries, being considered as public health problem in the whole world. Minerals presented in the form of organics complexes have been considered a good choice for these deficiencies, because it presents greater bioavailability when compared with the equivalents inorganic salts. The minerals copper, iron, manganese and zinc are essential to the organisms (human and animal), its physiological levels in accordance with the necessity contribute for the health maintence, resulting in economical benefits. In the present work it was carried through preparation and physical and chemical characterization of mineral complexes of Copper (Cu), Iron (Fe), Manganese (Mn) and Zinc (Zn) with partial hydrolysates of soy protein. The hydrolyses using the Aranzime and Alcalase enzymes had been more efficient than other enzymatic or acid hydrolyses, however only the Alcalase enzyme is approved for the manufacture of alimentary products for human consumption. Coordination between metals and the hydrolysate can be confirmed by the displacement of the ?NH2, ?aCOO- and ?sCOO- bands. The gotten copper, iron, manganese and zinc complexes, had the respective percentages of metal in its composition: 2,21%, 1,22%, 12,38% e 10,40%.
5

Hydroxytyrosol et effets santé : Nouvelles voies d’action via ses métabolites glucurono-conjugués / Biodisponibility and signaling pathways of olive oil polyphenols, hydroxytyrosol and its glucuronides, on vascular function in type 2 diabetes

Peyrol, Julien 17 July 2017 (has links)
Grâce à leurs propriétés antioxydantes, les phénols de l’huile d’olive sont reconnus comme les acteurs principaux de la réduction de la mortalité cardiovasculaire et du diabète de type 2 associée au régime méditerranéen. Cependant, la forte métabolisation de l’hydroxytyrosol, principal composé phénolique de l’huile d’olive, en glucuronides, remet en question son activité biologique.Un premier objectif de ce travail de thèse a été de mettre en évidence l’importance des glucuronides dans l’amélioration de la fonction vasculaire grâce à un effet antioxydant. Néanmoins et contrairement à l’hydroxytyrosol, qui peut être transporté directement par la bilitranslocase, les glucuronides doivent, dans un premier temps, être déconjugués par la β-glucuronidase afin d’exercer leur activité biologique.Un deuxième objectif de ce travail de thèse a été de mettre en évidence leurs effets chez des rats atteints de syndrome métabolique. Nous avons pu constater que ni l’hydroxytyrosol, ni ses glucuronoconjugués ne modulaient la fonction vasculaire.Enfin, un troisième objectif a été de regarder la répercussion d’une supplémentation en hydroxytyrosol, sur les facteurs de risque cardiovasculaire dans un modèle de souris atteintes de diabète de type 2. La supplémentation en hydroxytyrosol a réduit la prise de poids, les masses adipeuses et a eu des effets hypotenseurs. Ces effets hypotenseurs semblent être dus à une de la fonction des cellules musculaires lisses puisque nos travaux montrent une relaxation endothélium-indépendante améliorée. Nos travaux donnent un nouvel éclairage sur les effets de l’hydroxytyrosol et ses métabolites, tous deux contribuant, potentiellement, à la réduction de l’incidence des maladies cardiovasculaires et du diabète de type 2. / Olive oil polyphenols are well-known to lower cardiovascular mortality and type 2 diabetes incidence associated to the Mediterranean diet. However, the high metabolization rate of hydroxytyrosol, the main phenolic compound of olive oil, into glucuronides, questions its real biological effect. The first objective of this thesis was to evidence the importance of glucuronides of Hydroxytyrosol in the enhancement of vascular function through antioxidative properties. It was found that, unlike to hydroxytyrosol that can be directly transported with bilitranslocase glucuronides have to be deconjugated by β-glucuronidase to exert their biological activity. A second objective was to evidence the effects of Hydroxytyrosol and glucuronides on vascular function in diet-induced metabolic syndrome rats. Neither hydroxytyrosol nor glucuronides modulated vascular function in this pathological context. A third objective was to show the effect of a chronic Hydroxytyrosol supplementation in refined olive oil on cardiovascular risk factors in a mice model of Metabolic Syndrome. Hydroxytyrosol supplementation was able to reduce weight gain, white adipose tissues mass and to lower blood pressure. These hypotensive effects seem to be due in smooth muscle cells function. In conclusion, our works highlight the importance of Hydroxytyrosol and its glucuronoconjugated metabolites, both contributing to the reduction of the incidence of cardiovascular risk factors associated to type 2 diabetes and Metabolic syndrome.
6

Avaliação do impacto de diferentes variáveis no ensaio de dissolução intrínseca de metronidazol / Evaluation of the impact of different variables in the intrinsic dissolution test for metronidazole

Issa, Michéle Georges 30 March 2011 (has links)
O objetivo do presente trabalho foi avaliar o impacto de diferentes variáveis no ensaio de dissolução intrínseca de metronidazol. Inicialmente, as amostras, com diferentes graus de micronização, foram submetidas à caracterização físico-química, sendo realizados ensaios de solubilidade, tamanho de partícula, análise térmica (DSC/ TG), infravermelho por transformada de Fourier (FTIR), difratometria de raios X (DRX), análise de área superficial pelo método BET, microscopia óptica, densidade verdadeira e densidade compactada. Na sequência, foram realizados os ensaios de dissolução intrínseca segundo um planejamento experimental do tipo fatorial fracionado, sendo cada fator avaliado em três níveis. Para o delineamento, utilizou-se o programa Statistica 8.0. e os fatores estudados foram: velocidade de rotação, pressão utilizada na formação do compactado do fármaco, meio de dissolução e grau de micronização. Os resultados mostraram alteração nas propriedades reológicas do material conforme o aumento do grau de micronização, enquanto as demais propriedades não foram afetadas. Entre os fatores estudados no delineamento, a velocidade de rotação e o meio de dissolução, foram aqueles que exerceram influência significativa na dissolução intrínseca do metronidazol. Embora a solubilidade do fármaco não sofra influência do tamanho de partícula, valores superiores foram observados em HCl 0,1 M, meio em que também foram obtidas as mais elevadas velocidades de dissolução intrínseca (VDIs). / The purpose of this study is to evaluate the impact of different variables in the intrinsic dissolution test of metronidazol. Initially, the samples, with different levels of micronization, underwent physicochemical characterization, whereby they were tested for solubility, particle size, thermal analysis (DSC/TG), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (DRX), surface area analysis by the BET method, optical microscopy, true density and tapped density. Then, intrinsic dissolution tests were carried out according to fractional factorial experimental planning, with each factor being evaluated on three levels. The Statistica 8.0 software program was used for design, and the factors studied were: rotational velocity, pressure used in the formation of the compressed drug, dissolution medium and level of micronization. The results indicated alterations in the rheological properties of the material, as the level of micronization increased, while the remaining properties were unaffected. Among the factors studied in the design, the rotation speed and the dissolution medium were the factors that exercised the most significant influence on the intrinsic dissolution of metronidazol. Although the solubility of the drug is not influenced by particle size, higher values were observed in HCl 0.1 M, the medium in which the highest intrinsic dissolution rates (IDRs) were also obtained.
7

Avaliação do impacto de diferentes variáveis no ensaio de dissolução intrínseca de metronidazol / Evaluation of the impact of different variables in the intrinsic dissolution test for metronidazole

Michéle Georges Issa 30 March 2011 (has links)
O objetivo do presente trabalho foi avaliar o impacto de diferentes variáveis no ensaio de dissolução intrínseca de metronidazol. Inicialmente, as amostras, com diferentes graus de micronização, foram submetidas à caracterização físico-química, sendo realizados ensaios de solubilidade, tamanho de partícula, análise térmica (DSC/ TG), infravermelho por transformada de Fourier (FTIR), difratometria de raios X (DRX), análise de área superficial pelo método BET, microscopia óptica, densidade verdadeira e densidade compactada. Na sequência, foram realizados os ensaios de dissolução intrínseca segundo um planejamento experimental do tipo fatorial fracionado, sendo cada fator avaliado em três níveis. Para o delineamento, utilizou-se o programa Statistica 8.0. e os fatores estudados foram: velocidade de rotação, pressão utilizada na formação do compactado do fármaco, meio de dissolução e grau de micronização. Os resultados mostraram alteração nas propriedades reológicas do material conforme o aumento do grau de micronização, enquanto as demais propriedades não foram afetadas. Entre os fatores estudados no delineamento, a velocidade de rotação e o meio de dissolução, foram aqueles que exerceram influência significativa na dissolução intrínseca do metronidazol. Embora a solubilidade do fármaco não sofra influência do tamanho de partícula, valores superiores foram observados em HCl 0,1 M, meio em que também foram obtidas as mais elevadas velocidades de dissolução intrínseca (VDIs). / The purpose of this study is to evaluate the impact of different variables in the intrinsic dissolution test of metronidazol. Initially, the samples, with different levels of micronization, underwent physicochemical characterization, whereby they were tested for solubility, particle size, thermal analysis (DSC/TG), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (DRX), surface area analysis by the BET method, optical microscopy, true density and tapped density. Then, intrinsic dissolution tests were carried out according to fractional factorial experimental planning, with each factor being evaluated on three levels. The Statistica 8.0 software program was used for design, and the factors studied were: rotational velocity, pressure used in the formation of the compressed drug, dissolution medium and level of micronization. The results indicated alterations in the rheological properties of the material, as the level of micronization increased, while the remaining properties were unaffected. Among the factors studied in the design, the rotation speed and the dissolution medium were the factors that exercised the most significant influence on the intrinsic dissolution of metronidazol. Although the solubility of the drug is not influenced by particle size, higher values were observed in HCl 0.1 M, the medium in which the highest intrinsic dissolution rates (IDRs) were also obtained.
8

Rôle des Pseudomonas fluorescents dans la biodisponibilté des métaux contaminant les minéraux du sol : application à la phytoremédiation / Role of fluorescent Pseudomonas in the biodisponibility of metals contamining the soil minerals : application to the phytoremediation

Ferret, Claire 19 September 2012 (has links)
Le développement de l’industrie et de l’agriculture a entraîné l’accumulation d’éléments métalliques dans les sols. Dans ces écosystèmes, la fraction vivante intervient de façon importante dans la modification de la rétention des contaminants. Parmi les techniques de décontamination, la phytoremédiation apparaît comme un outil de choix. Si un des inconvénients majeurs de cette technique réside dans des durées de traitement pouvant atteindre plusieurs années, l’ajout de micro-organismes couplé aux plantes améliorerait les prélèvements et réduirait les temps de décontamination. Cette étude s’est intéressée aux possibilités de développer des procédés de phytoremédiation associés à des bactéries productrices de sidérophores, molécules ayant une forte affinité pour le fer mais également pour d’autres métaux. Dans ce contexte, un système de complexité croissante, jusqu’au modèle complet comprenant les constituants du sol, les bactéries, les métaux contaminants et les plantes, a été étudié avec pour objectif la compréhension des processus intervenant dans ces différentes interactions. Ces travaux ont conduit, dans un premier temps, à la compréhension, notamment par une approche de biologie moléculaire, des interactions intervenant entre des minéraux du sol, des argiles et des oxy-hydroxydes de fer, et une bactérie productrice de sidérophores, Pseudomonas aeruginosa. Les résultats ont mis en évidence le rôle majeur de l’un de ces sidérophores, la pyoverdine, ainsi que du biofilm, dans la dissolution des minéraux par cette bactérie. Une étude en fluorimétrie et dosages des métaux a, quant à elle, montré que la pyoverdine était capable de complexer des métaux contaminants adsorbés sur les argiles ou présents dans la structure cristalline des oxy-hydroxydes de fer. Enfin, ces travaux ont abouti à la mise en place du système d’étude dans sa globalité. Si la pyoverdine ou les bactéries productrices de sidérophores n’ont pas amélioré le prélèvement par les plantes du cadmium et du nickel, des résultats prometteurs ont cependant été obtenus pour le cuivre. De plus, les bactéries productrices de sidérophores s’avèrent être des cibles intéressantes en phytostabilisation. / The industrial and agricultural development caused a metallic element accumulation in the soils. In these ecosystems, the living fraction significantly operates in the changes of contaminants retention. Among the decontamination techniques, the phytoremediation appears as a tool of choice. If one of major disadvantages of this technique is the long-term remediation process, the addition of microorganisms with the plants could enhance the uptakes and decrease the time to remediate. This work focused on the possibility to develop processes for siderophore-producing bacteria-assisted phytoremediation, siderophores being molecules with a high affinity for iron and also able to chelate other metals. In this context, a system with an increasing complexity until a complete model including the soil constituents, the bacteria, the contaminant metals and the plants, has been studied to understand the processes involved in these different interactions. The understanding of the interactions between the soil minerals, clays and iron oxydydroxides, and a siderophore-producing bacteria, Pseudomonas aeruginosa, have been first performed with, in particular, a molecular biology approach. These results have highlighted the major role of the one of siderophores, the pyoverdine, and also the biofilm in the mineral dissolution by this bacteria. Fluorimetry and metal quantification assays showed that the pyoverdine was able to chelate the contaminant metals adsorbed on the clays or present in the crystal structure of the iron oxyhydroxides. Lastly, the global system has demonstrated that if the pyoverdine or the siderophore-producing bacteria do not enhance the cadmium and nickel uptake by plants, promising results were obtained for copper. Moreover, siderophore-producing bacteria turn out to be interesting asset for the phytostabilization.
9

Développement de méthodes analytiques basées sur la spectrométrie de masse de haute résolution pour l’étude de molécules contenant des métaux chez les organismes vivants / High resolution elemental and molecular mass spectrometry for studies of endogenous metal-containing molecules in living organisms

Wang, Shuanglong 25 September 2017 (has links)
Les ions métalliques (Fe, Zn, Cu, Mn, Ni, Co, Mo…) jouent un rôle vital dans un grand nombre de processus biologiques. Leur carence et leur excès entraînent des défauts de croissance voire la mort. Pour survivre et croître, certaines bactéries ont développé des stratégies pour acquérir les métaux dans leur environnement basées sur la synthèse de ligands complexant les métaux. Les plantes, elles, stockent les métaux et les transportent entre les tissus sous des formes chimiques particulières et un rôle grandissant pour les petits complexes métalliques semble se révéler. La spéciation des métaux gouvernerait donc leur biodisponibilité pour les consommateurs en ce qui concerne les plantes comestibles. Cette thèse a pour but le développement de méthodes analytiques pour l’identification et la quantification des formes chimiques des métaux chez les bactéries et les plantes.Les techniques de séparation chromatographique, comme la chromatographie d’exclusion stérique (SEC) et la chromatographie d’interaction hydrophile (HILIC), furent couplées à la spectrométrie de masse (MS) avec une ionisation préalable par plasma induit (ICP MS) ou par électrospray pour une détection élémentaire et moléculaire respectivement. La méthodologie analytique développée ici, qui est basée sur l’utilisation de l’HILIC avec détection double par ICP MS et électrospray MS, s’est avérée cruciale pour la découverte et la caractérisation de deux nouveaux métallophores, la staphylopine chez Staphylococcus aureus et la pseudopaline chez Pseudomonas aeruginosa. Ces métallophores sont synthétisés et exportés par les bactéries et servent pour l’acquisition des métaux de transition divalents dans les milieux très pauvres en métaux grâce à leur pouvoir complexant.Des techniques dédiées de préparation d’échantillons, incluant le fractionnement des extraits solubles à l’eau, furent mises en place pour l’analyse du fer dans le maïs. Les approches instrumentales développées, notamment après le fractionnement du fer l’échantillon, permirent l’identification par spectrométrie de masse de complexes du fer avec le citrate, le muginéate et le phytate dans les grains de maïs. Il existe aussi une différence significative dans les concentrations de certaines polyamines entre certaines variétés de graines contenant du fer faiblement biodisponible et celles contenant du fer fortement biodisponible. La plus grande abondance de complexe fer-muginéate dans les extraits gastro-intestinaux des variétés à fer fortement biodisponible semblerait indiqué un rôle important pour ce complexe dans la biodisponibilité du fer. Finalement, des ratios molaires plus faibles entre le phytate extrait et le fer qui lui est associé sembleraient aussi être un des facteurs lié à une plus grande biodisponibilité du fer. / Metal (Fe, Zn, Cu, Mn, Ni, Co, Mo…) ions play a vital role in a large number of biological processes. Both their deficiency and excess will lead to severe growth impairment or death. In order to survive and to grow, bacteria developed strategies to acquire metals from the environment based on the synthesis of metal complexing ligands. Plants store metals and transport them between tissues in particular chemical forms and a rising role for small metal complexes seems to be revealed. Therefore their speciation governs the bioavailability of the metals to consumers in the case of edible plants. This thesis aims at the development of analytical methods for the identification and quantification of metal chemical forms in bacteria and in plants.Chromatographic separation techniques, such as size exclusion chromatography (SEC) and hydrophilic interaction chromatography (HILIC) were coupled to mass spectrometry (MS) using ionization in an inductively coupled plasma (ICP MS) or electrospray for elemental and molecular detection, respectively. The developed analytical methodology based on HILIC with dual ICP MS and electrospray MS detection turned out to be crucial for the discovery and characterization of two novels metallophores, staphylopine in Staphylococcus aureus and pseudopaline in Pseudomonas aeruginosa. These metallophores are synthesized and exported by the bacteria and serve for the uptake of divalent transition metal in metal scarce conditions by means of chelation. Dedicated samples preparation techniques, including fractionation of water soluble extracts, were developed for iron analyses in maize. The developed instrumental approaches following the iron fractionation methods allowed the identification by mass spectrometry of citrate, mugineate and phytate complexes with iron in maize kernels. There was also a significant difference in some polyamine concentrations observed between some kernels with low and high bioavailable iron. The higher abundance of the iron-mugineate complex in the gastrointestinal extract in high bioavailable maize variety possibly indicates that iron-mugineate would have an important role in iron biodisponibility. Finally, lower molar ratios between extracted phytate and iron associated to it would seem to be also a key aspect for higher iron bioavailability.
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Bioacumulação e biomagnificação de metais pesados em teias tróficas de estuários do sul-sudeste do Brasil / Bioaccumulation and biomagnification of heavy metals in trophic webs of estuaries of the southern and southeastern of Brazil

Trevizani, Tailisi Hoppe 09 October 2018 (has links)
A região costeira do Brasil é historicamente impactada por atividades antrópicas, que liberam contaminantes, como os metais pesados. Nos estuários de Paranaguá (PR), Cananéia e Santos (SP), tais atividades estão presentes em diferentes níveis. Neste estudo foram investigadas as concentrações de arsênio, cádmio, chumbo, cobre, cromo, níquel, selênio, zinco e mercúrio, além de isótopos estáveis de carbono e nitrogênio, em sedimentos, fragmentos vegetais e organismos marinhos, como invertebrados bentônicos, peixes bentívoros e mamíferos marinhos, coletados nos três estuários. As amostragens foram realizadas em 2015, sendo as análises de isótopos realizadas por EA-IRMS e as análises de metais pesados realizadas por ICP OES-VGA e ICP-MS. As razões isotópicas permitiram a distinção entre fontes de matéria orgânica e nível trófico. Exemplares da ictiofauna e de cetáceos analisados não apresentaram distinção entre os níveis tróficos 3 e 4, indicando uma dieta generalista para estes animais e potencial compartilhamento de nicho trófico. Os metais apresentaram maiores concentrações nos sedimentos do estuário de Santos, coincidindo com o local com maior intensidade de atividades antrópicas. Comparando os estuários há maior acumulação de: Cr, Cu, Zn e Hg em Paranaguá, As e Pb em Cananéia, e Cd, Ni e Se em Santos, resultados justificados por atividades antrópicas, fontes naturais e características geoquímicas de cada região. A tendência de biomagnificação de Se foi observada nas teias tróficas de todos os estuários, e de Zn e Hg nas teias de Paranaguá e Cananéia. Entretanto, As, Cr, Cu, Ni e Pb demostraram tendência a biodiluição nas teias tróficas estudadas, com maior bioacumulação em invertebrados bentônicos. Portanto, este estudo traz um panorama atual da distribuição espacial e trófica de metais pesados nos estuários, colaborando com o monitoramento e ações de gestão costeira. / The coastal region of Brazil is historically impacted by anthropic activities, which release contaminants such as heavy metals. In the estuaries of Paranaguá (PR), Cananéia and Santos (SP), these activities are present in different levels. In the present study, concentrations of arsenic, cadmium, lead, copper, chromium, nickel, selenium, zinc and mercury were investigated, as well as stable carbon and nitrogen isotopes in sediments, plant fragments and marine organisms such as benthic invertebrates, benthivorous fish and marine mammals, collected in the three estuaries. Samples were collected in 2015, with isotope analysis performed by EA-IRMS and heavy metal analysis performed by ICP OES-VGA and ICP-MS. Isotopic ratios allowed the distinction between organic matter sources and trophic level. The specimens of the ichthyofauna and cetaceans analyzed did not present distinction between trophic levels 3 and 4, indicating a generalist diet for these animals and a potential sharing of trophic niche. The metals have presented higher concentrations in the sediments from Santos estuary, what coincides with the place with greater intensity of anthropic activities. Comparing the estuaries, there is more bioaccumulation of Cr, Cu, Zn and Hg in Paranaguá, As and Pb in Cananéia, and Cd, Ni and Se in Santos; results which are justified by anthropic activities, natural sources and geochemical characteristics of each region. A biomagnification tendency of Se was observed in the trophic webs of all estuaries, and Zn and Hg in the Paranaguá\'s and Cananéia\'s webs. However, As, Cr, Cu, Ni and Pb displayed a tendency to biodilution in the studied trophic webs; with a higher bioaccumulation in benthic invertebrates. Therefore this study provides a current overview of the spatial and trophic distribution of heavy metals in the estuaries. Thus, it is collaborating with the monitoring and actions of coastal management.

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