Devido à grande incidência de pessoas com lesões de pele como queimaduras e úlceras e à baixa disponibilidade de doadores, houve a necessidade de desenvolvimento de biomateriais com a capacidade de mimetizar a pele. Para o desenvolvimento desses biomateriais, polímeros são utilizados na tentativa de alcançar características mais próximas as do órgão alvo. Neste sentido, nosso grupo vem desenvolvendo, há alguns anos, substitutos dermo-epidérmicos, particularmente membranas biodegradáveis e biocompatíveis constituídas de PVAl e quitosana. O PVAl, polímero sintético, foi utilizado para mimetizar a porção dérmica humana e a quitosana, polímero de origem natural, foi utilizada neste estudo para favorecer o crescimento e manutenção da porção epidérmica. Devido às variações destes polímeros obtidos comercialmente, o objetivo deste estudo foi caracterizar as suas propriedades físico-químicas, comparando-as com a membrana anteriormente obtida pelo nosso grupo, com o intuito de confirmar hipóteses de interferências ressaltadas nesse estudo. As membranas de PVAl em estudo (PVAl MP) que obtiveram características morfológicas mais semelhantes ao padrão, foram as irradiadas a 13 e 15 kGy, sendo esta última escolhida por atingir a dose mínima necessária para se obter um material estéril. Estas membranas também foram as que apresentaram maior porcentagem de poros entre 70 e 100 m2. Quanto à quitosana, as principais características estudadas foram o grau de acetilação (DA) e a massa molecular média, ambos os resultados indicaram características diferentes daquelas indicadas comercialmente. Diversos protocolos de preparações de membranas foram feitos a partir de solução de quitosana (2%). A membrana composta de solução de quitosana homogeneizada com glicerol (20%) e seca a temperatura ambiente, apresentou a melhor interação com os queratinócitos. Para a finalização do trabalho esta solução de quitosana foi vertida sobre a membrana de PVAl, liofilizada e intumescida com solução de quitosana (2%) e o conjunto foi mantido à temperatura ambiente até formação do filme de quitosana na face superior, obtendo-se assim uma membrana composta compatível com o sistema dermo-epidérmico. / Due to the frequent incidence of people with skin lesions such as burns and ulcers and the lack of available donors, biomaterials with the capacity to mimic skin must be developed. In order to develop these biomaterials, polymers are used in the attempt to achieve characteristics which are closer to the target organ. In this direction, for several years our group has been developing dermo-epidermic substitutes, specifically biodegradable and biocompatible membranes made up of PVAI and chitosan. PVAI, a synthetic polymer, was used to imitate part of the human dermis and chitosan, a polymer of organic origin, was used in this study to stimulate growth and maintenance of the epidermis. Due to the variations of these commercially obtained polymers, the objective of this study was to characterize their physical and chemical properties, comparing them with the membrane previously obtained by our group with the intention of confirming the hypotheses of interferences put forward in this study. The PVAI membranes in the study (PVAI MP) that obtained characteristics most similar to the standard were those irradiated with 13 and 15 kGy; this last was chosen because it was the minimum dose necessary to achieve sterility. These membranes were also those which had the largest percentage of pores between 70 and 100 m. For chitosan, the principal characteristics studied were the degree of acetylation (DA) and average molecular weight, both results demonstrated different characteristics than commercially indicated. Various membrane preparation protocols were carried out from the chitosan solution (2%). The membrane composed of the solution of chitosan homogenized with glycerol (20%) and dried at room temperature had the best interaction with keratinocytes. To finalize the study, this chitosan solution was poured over a PVAI membrane, lyophilized and impregnated with chitosan (2%) solution and the compound was kept at room temperature until a chitosan film formed on the upper surface, thus obtaining a composite membrane compatible with the dermo-epidermic system.

Devido à grande incidência de pessoas com lesões de pele como queimaduras e úlceras e à baixa disponibilidade de doadores, houve a necessidade de desenvolvimento de biomateriais com a capacidade de mimetizar a pele. Para o desenvolvimento desses biomateriais, polímeros são utilizados na tentativa de alcançar características mais próximas as do órgão alvo. Neste sentido, nosso grupo vem desenvolvendo, há alguns anos, substitutos dermo-epidérmicos, particularmente membranas biodegradáveis e biocompatíveis constituídas de PVAl e quitosana. O PVAl, polímero sintético, foi utilizado para mimetizar a porção dérmica humana e a quitosana, polímero de origem natural, foi utilizada neste estudo para favorecer o crescimento e manutenção da porção epidérmica. Devido às variações destes polímeros obtidos comercialmente, o objetivo deste estudo foi caracterizar as suas propriedades físico-químicas, comparando-as com a membrana anteriormente obtida pelo nosso grupo, com o intuito de confirmar hipóteses de interferências ressaltadas nesse estudo. As membranas de PVAl em estudo (PVAl MP) que obtiveram características morfológicas mais semelhantes ao padrão, foram as irradiadas a 13 e 15 kGy, sendo esta última escolhida por atingir a dose mínima necessária para se obter um material estéril. Estas membranas também foram as que apresentaram maior porcentagem de poros entre 70 e 100 m2. Quanto à quitosana, as principais características estudadas foram o grau de acetilação (DA) e a massa molecular média, ambos os resultados indicaram características diferentes daquelas indicadas comercialmente. Diversos protocolos de preparações de membranas foram feitos a partir de solução de quitosana (2%). A membrana composta de solução de quitosana homogeneizada com glicerol (20%) e seca a temperatura ambiente, apresentou a melhor interação com os queratinócitos. Para a finalização do trabalho esta solução de quitosana foi vertida sobre a membrana de PVAl, liofilizada e intumescida com solução de quitosana (2%) e o conjunto foi mantido à temperatura ambiente até formação do filme de quitosana na face superior, obtendo-se assim uma membrana composta compatível com o sistema dermo-epidérmico. / Due to the frequent incidence of people with skin lesions such as burns and ulcers and the lack of available donors, biomaterials with the capacity to mimic skin must be developed. In order to develop these biomaterials, polymers are used in the attempt to achieve characteristics which are closer to the target organ. In this direction, for several years our group has been developing dermo-epidermic substitutes, specifically biodegradable and biocompatible membranes made up of PVAI and chitosan. PVAI, a synthetic polymer, was used to imitate part of the human dermis and chitosan, a polymer of organic origin, was used in this study to stimulate growth and maintenance of the epidermis. Due to the variations of these commercially obtained polymers, the objective of this study was to characterize their physical and chemical properties, comparing them with the membrane previously obtained by our group with the intention of confirming the hypotheses of interferences put forward in this study. The PVAI membranes in the study (PVAI MP) that obtained characteristics most similar to the standard were those irradiated with 13 and 15 kGy; this last was chosen because it was the minimum dose necessary to achieve sterility. These membranes were also those which had the largest percentage of pores between 70 and 100 m. For chitosan, the principal characteristics studied were the degree of acetylation (DA) and average molecular weight, both results demonstrated different characteristics than commercially indicated. Various membrane preparation protocols were carried out from the chitosan solution (2%). The membrane composed of the solution of chitosan homogenized with glycerol (20%) and dried at room temperature had the best interaction with keratinocytes. To finalize the study, this chitosan solution was poured over a PVAI membrane, lyophilized and impregnated with chitosan (2%) solution and the compound was kept at room temperature until a chitosan film formed on the upper surface, thus obtaining a composite membrane compatible with the dermo-epidermic system.

The present study explored the spatial and temporal demographic trends in oyster population dynamics and their relationships to freshwater inflows and the pathogen Dermo (Perkinsus marinus) on three reefs (Shell, Mad Island, and Sammy?s) in West Matagorda Bay, Texas. The objectives were to design and link three population models that simulate oyster population dynamics and integrate the environmental factors that influence growth, reproduction and settlement of larvae among these three reefs. The following variables were evaluated: relative abundance of oyster spat, submarket- and market-size oysters, average weighted incidence of Dermo and percent Dermo infection (prevalence) in submarket- and market-size oysters and their relationships to environmental variables of salinity, temperature, flow and distance from freshwater sources. Using a 30-month continuous dataset, environmental variables accounted for 36% of the variation in Dermo-related variables among the three reefs, and were also positively correlated with distance from freshwater sources. The relative abundance of spat and dead oysters was related to peaks in freshwater inflows occurring 30 days prior to larval settlement. Using these spatial and temporal relationships among biological and environmental variables, and data from five years of monitoring three reefs in Matagorda Bay, an integrated Stella model was developed that simulated oyster population responses to stochastic environmental changes over a 50-year period. Although the geological and structural complexity of each reef appeared to be similar, the model showed the relationship of growth, spawning and spat set were related to hydrologic variation between different reefs and time periods. The model revealed that up-estuary reefs relied on the distribution of larvae from down-estuary reefs following mortality related to freshwater inflow. The model also indicated that loss of freshwater inflows to down-estuary reefs resulted in higher sustained Dermo infections, thus loss of spawning potential and subsequent distribution of larvae to up-estuary reefs. The three oyster populations in West Matagorda Bay provide spawning connectivity and function as an integrated resource for sustaining all oyster reef populations in this bay system. The model presented in this research provides a basis for understanding the population dynamics of WMB as well as a better understanding of the interaction among the reefs that sustain these populations. The model developed in this investigation provides a basis for developing oyster population models for other bay systems and for future research regarding hydrologic influences on oyster population dynamics.

The present study explored the spatial and temporal demographic trends in oyster population dynamics and their relationships to freshwater inflows and the pathogen Dermo (Perkinsus marinus) on three reefs (Shell, Mad Island, and Sammy?s) in West Matagorda Bay, Texas. The objectives were to design and link three population models that simulate oyster population dynamics and integrate the environmental factors that influence growth, reproduction and settlement of larvae among these three reefs. The following variables were evaluated: relative abundance of oyster spat, submarket- and market-size oysters, average weighted incidence of Dermo and percent Dermo infection (prevalence) in submarket- and market-size oysters and their relationships to environmental variables of salinity, temperature, flow and distance from freshwater sources. Using a 30-month continuous dataset, environmental variables accounted for 36% of the variation in Dermo-related variables among the three reefs, and were also positively correlated with distance from freshwater sources. The relative abundance of spat and dead oysters was related to peaks in freshwater inflows occurring 30 days prior to larval settlement. Using these spatial and temporal relationships among biological and environmental variables, and data from five years of monitoring three reefs in Matagorda Bay, an integrated Stella model was developed that simulated oyster population responses to stochastic environmental changes over a 50-year period. Although the geological and structural complexity of each reef appeared to be similar, the model showed the relationship of growth, spawning and spat set were related to hydrologic variation between different reefs and time periods. The model revealed that up-estuary reefs relied on the distribution of larvae from down-estuary reefs following mortality related to freshwater inflow. The model also indicated that loss of freshwater inflows to down-estuary reefs resulted in higher sustained Dermo infections, thus loss of spawning potential and subsequent distribution of larvae to up-estuary reefs. The three oyster populations in West Matagorda Bay provide spawning connectivity and function as an integrated resource for sustaining all oyster reef populations in this bay system. The model presented in this research provides a basis for understanding the population dynamics of WMB as well as a better understanding of the interaction among the reefs that sustain these populations. The model developed in this investigation provides a basis for developing oyster population models for other bay systems and for future research regarding hydrologic influences on oyster population dynamics.

L’entreprise SEPROSYS est une société spécialisée dans le développement de solutions d'extraction et de séparation de molécules. Au cours de l’année 2011, l’entreprise a développé un procédé innovant de séparation et de purification fractionnée de biomolécules issues de macroalgues marines. Ce travail de thèse a pour objectif de trouver des applications aux fractions extraites selon le procédé d’extraction et de purification de la société SEPROSYS, et en particulier la fraction des polysaccharides sulfatés, dans deux domaines distincts : en pharmaceutique pour leur activité anti-coagulante et en cosmétique pour leur activité anti-âge. La première partie de nos travaux se penche sur le potentiel des polysaccharides sulfatés de macroalgues comme anti-coagulants. Pour cela, des extraits aqueux de différentes macroalgues brunes, rouges et vertes ont été préparés et leur activité anti-coagulante a été mesurée. Les algues présentant le meilleur potentiel ont ensuite été traitées au moyen du procédé SEPROSYS® afin de purifier leurs polysaccharides sulfatés et d’étudier leur activité anti-coagulante. De plus, l’objectif de ce travail consiste également à mieux comprendre la relation structure-fonction de l'activité anticoagulante d'ulvanes. A cette fin, des ulvanes issus d’Ulva sp. de pureté élevée ont été produits par le procédé SEPROSYS®, soumis à des modifications chimique (hypersulfatation) et physique (dépolymérisation) et leur activité anticoagulante a été étudiée. La deuxième partie de nos travaux concerne l’évaluation du potentiel de ces macroalgues comme agents actifs utilisables en dermo-cosmétique, en particulier pour leur activité anti-âge. Dans ce but, différentes fractions de macroalgues brunes, rouges et vertes ont été testées sur des lignées cellulaires de fibroblastes dermiques humains et leur effet sur la production de collagène par ces fibroblastes a été étudié. Enfin, le potentiel d’ulvanes extraits d’Uva sp. par le procédé de l’entreprise SEPROSYS pour stimuler la biosynthèse de collagène et d’acide hyaluronique par ces mêmes fibroblastes a été déterminé. / SEPROSYS is a company specialized in the development of solutions for the extraction and separation of molecules. In 2011, the company has developed an innovative process of fractionated separation and purification of biomolecules from macroalgae. The purpose of this thesis work is to find applications for the purified fractions from the SEPROSYS® process and in particular the sulfated polysaccharides, for two distinct biological activities : as pharmaceutical for their anti-coagulant activity and as dermo-cosmetics for their anti-aging activity. The first part of our work focus on the potential of sulfated polysaccharides from macroalgae as anti-coagulant agents. To this end, aqueous extracts from brown, red and green macroalgae were prepared and their anti-coagulant activity was measured. The best macroalgae were then processed with the SEPROSYS procedure in order to purify the sulfated polysaccharides and study their activity. Furthermore, one of the objectives of this work was to acquire a better understanding of the structure/anti-coagulant function relationship of ulvans. Ulvans of high purity were extracted from Ulva sp. with the SEPROSYS® process, submitted to chemical (hypersulfatation) and physical (depolymerization) modifications and their anti-coagulant activity was measured. The second part of our work relates to the potential of the macroalgae as active agents to be used in dermo-cosmetics, and, in particular, for their anti-aging activity. Different brown, red and green macroalgae fractions were thus tested on normal human dermal fibroblasts cell lines and their effects on the collagen production were measured. Furthermore, the capacity of different molecular weight ulvans extracted from Ulva sp. to stimulate the collagen and hyaluronan biosynthesis was studied. To this end, we developed an efficient depolymerization procedure using ion exchange resins.

Le mélanome cutané est le plus agressif des cancers de la peau. Sa dangerosité provient de sa grande capacité à former des métastases. A l’heure actuelle, la prévention et la détection précoce de la lésion primitive restent les seuls moyens d’aboutir à une guérison. En effet, ce cancer est particulièrement reconnu pour sa résistance aux thérapies actuelles sous sa forme métastatique. Le mélanome se développe à partir des mélanocytes de la peau, qui après des évènements oncogéniques, prolifèrent de manière anarchique dans l’épiderme. Par la suite, certaines cellules de la tumeur acquièrent un phénotype invasif qui leur permet de franchir la jonction dermo-épidermique et envahissent le derme, pour y proliférer et le coloniser en profondeur. Une fois dans le derme, les cellules de mélanome peuvent disséminer à distance par voie lymphatique et sanguine pour former des métastases dans les organes cibles. La dégradation de la jonction dermo-épidermique conduisant à l’invasion du derme est la première étape qui mène à la formation de métastase. Dans l’équipe on s’intéresse à l’étude des mécanismes de l’invasion dermique. Grâce au travail fourni, nous avons pu identifier un nouvel acteur moléculaire intervenant dans l’invasion précoce du mélanome cutané : La Tétraspanine 8. Le but de ce travail de thèse a donc été de définir le rôle et le mode d’action de cette protéine. Nous avons réussi à établir l’implication de la Tétraspanine 8 dans la perte d’adhérence des cellules de mélanome aux protéines de la matrice extracellulaire, en association avec une inhibition de l’activation de l’intégrine β1 et avec une diminution de la phosphorylation de la kinase ERK. Nous avons également obtenu des résultats impliquant la Tspan8 dans l’invasion du derme par les cellules de mélanome, en association avec augmentation de la stabilité de β-caténine. Enfin, les tests de tumorigénicité, réalisés dans les souris Nude, permettent d’établir que l’expression de Tspan8 procure aux cellules de mélanome un pouvoir tumorigène. À long terme, ce travail vise à faire émerger de nouveaux marqueurs de pronostic mais aussi de nouvelles cibles thérapeutiques visant à bloquer la progression du mélanome avant l’apparition des métastases / Cutaneous melanoma is the most aggressive skin cancer since its great ability to form metastasis. Successful treatment depends on its early detection, as the metastatic form is resistant to current therapies. Melanoma cells, developing from the melanocytes of the skin, proliferate first in the epidermis. Subsequently, some tumor cells acquire an invasive phenotype, degrade the dermal-epidermal junction and invade the dermis where they proliferate and deeply colonize the tissue. Melanoma cells can then enter the circulatory system and disseminate to form metastases in the target organs. Degradation of the basement membrane and invasion of the dermis are therefore the early events of melanoma tumor invasion and the first step leading to the formation of metastases. In the team, we are interested in the study of the poorly understood mechanisms of dermal invasion. We have identified a novel molecular mediator of the early cutaneous melanoma invasion : the Tetraspanin 8. The aim of this thesis was therefore to define the role and the mode of action of this protein. We have established the involvement of Tetraspanin 8 in the loss of melanoma cells anchorage to matrix proteins and also in the degradation of dermalepidermal junction components. We have then obteined data that indicate the involvement of ERK/MAPK and PI3K/AKT signaling pathways, in the invasive phenotype, downstream of the Tetraspanin 8. Although much is yet to be learned ragarding the clinical relevace of Tetraspanin 8 function, we postulate that it could be a promising new therapeutic target in anti-invasive therapies for cutaneous melanoma

Abstract Five sites in Tampa Bay, Florida, were sampled monthly from February 2006 to January 2007. These sites were located at the mouth of the Alafia River, in an inlet of Cross Bayou, on the easement of Gandy Bridge, near mangrove in Manatee County, and an inlet of Salt Creek, off Bayboro Harbor. Standard methods were used to determine shell height and Condition Index (CI). Intensity and prevalence of Perkinsus marinus were analyzed using Ray's Thioglycollate medium test, while Haplosporidium nelsoni was studied by histological examination. Histological methods were also used to determine sex ratios, reproductive phases, and egg diameters. Perkinsus marinus was identified at all sites, exhibiting a bimodal seasonality, with maximum intensity and prevalence in late winter and late summer, and with minima in late spring and late autumn. No evidence for H. nelsoni infections was found in any of the 1800 specimens examined. Condition Index also exhibited seasonal bimodality with higher CI values found in specimens collected in late spring and late autumn. Cross Bayou and Salt Creek sites were distinct from each other and from the other sites with respect to parameters assessed, while oyster populations at the Alafia, Gandy and Manatee sites were similar. Overall, this study supports previous hypotheses that southeastern oyster beds do not experience temperatures or salinities low enough to induce dormancy in P. marinus; thus, it is prevalent throughout the year.

This master thesis deals with possibilities for addressing customers at point of sale. Its objective is to apply current theoretical approaches to the field of research in order to design a concrete solution for increase of communication effectiveness of dermo-cosmetics products at pharmacies.