Phaeodactylum et Nannochloropsis sont des espèces photosynthétiques modèles pour le métabolisme des glycérolipides, se distinguant par un enrichissement en acides gras polyinsaturés à très longues chaînes (VLC-PUFA) et de grandes quantités en triacylglycérol (TAG). Les proportions des différents lipides sont influencées par des facteurs environnementaux. Nous avons caractérisé le remodelage lipidique chez Phaeodactylum en réponse à la carence en azote et en phosphate. Ces limitations en nutriments induisent une accumulation de TAG, exploitable comme biocarburant. Nous avons identifié de nouveaux composés induisant l'accumulation de TAG et étudié le rôle potentiel du monoxyde d’azote (NO•) dans la régulation du métabolisme lipidique. Nous avons montré qu’en fonction du site de production, le NO• était un signal émis lorsque les conditions de vie étaient critiques, déclenchant l'accumulation de TAG.Les VLC-PUFAs sont produits par des élongases et des désaturases localisées dans le RE. Nous avons identifié une nouvelle classe d’élongases d’acides gras saturés, agissant sur le 16:0, et appelées Δ0-ELO. Le knock out de Δ0-ELO1 de Nannochloropsis réduit le niveau du monogalactosyldiacylglycérol (MGDG), principal lipide des chloroplastes. Ce phénotype met en évidence le rôle de Δ0-ELO1 dans la «voie oméga» qui contrôle le trafic des VLC-PUFAs. Nous avons débuté une dissection de la «voie oméga» par des approches de génétique et des analyses du remodelage lipidique à basse température chez Nannochloropsis. Le diacylglycéryl hydroxyméthyltriméthyl-β-sérine (DGTS) apparaît comme le précurseur de base pour importer des VLC-PUFAs vers le chloroplaste, suivant une voie très régulée du DGTS au MGDG. De plus nous avons montré des fonctions possibles du MGDG et des VLC-PUFAs dans la photoprotection et la régulation de la fluidité membranaire latérale. / Phaeodactylum and Nannochloropsis are photosynthetic model species for glycerolipid metabolism, standing out by an enrichment of very-long-chain polyunsaturated fatty acids (VLC-PUFAs) and high contents of neutral lipids such as triacylglycerol (TAG). Lipid profiles are influenced by environmental factors. We characterized the lipid remodelling occurring in Phaeodactylum in response to nitrogen and phosphate starvation. Nutrient limitations induce neutral lipid accumulation, which may be exploited as biofuels. We identified new triggers of TAG accumulation and investigated a potential role of nitric oxide (NO•) as second messenger in the regulation of neutral lipid levels. We conclude that in dependence of the production site, NO• serves as a signalling molecule for critical life conditions and thereby triggers TAG accumulation.VLC-PUFAs are produced by ER-located elongases and desaturases. We identified a novel class of elongases, called Δ0-ELOs, acting on saturated fatty acids, most importantly 16:0. Knock out of Δ0-ELO1 in Nannochloropsis resulted in reduced monogalactosyldiacylglycerol (MGDG) levels. MGDG is the major chloroplast lipid. This indicated a role of this initial elongase in fatty acid fate determination and thus in the elusive “omega pathway” for VLC-PUFA trafficking. We have started to investigate the “omega pathway” by reverse genetic approaches and analyses of low-temperature induced lipid remodelling in Nannochloropsis. Diacylglyceryl hydroxymethyltrimethyl-β-serine (DGTS) appears most likely at the base for the chloroplast import of VLC-PUFA, following a dynamically regulated DGTS-to-MGDG pathway. Additionally, we gave insights into possible functions of MGDG and VLC-PUFA in photoprotection and regulation of membrane fluidity.

Master of Science / Department of Animal Sciences and Industry / Terry Houser / Two studies were conducted to determine the effectiveness of naturally smoked sugar in a conventional and natural curing brines to inhibit lipid oxidation in frozen, aerobically packaged, layout style bacon. Commercial pork bellies were trimmed and cut in half creating anterior and posterior sections. Each section was randomly assigned to one of two treatments targeted 12% injection: control brine or a brine containing naturally smoked sugar (n =15/treatment). In the first study a conventional control brine consisted of 76.4% water, 11.8% salt, 8.00% sugar, 1.70% sodium phosphate, 1.60% sodium nitrite, and 0.450% sodium erythorbate. The treatment brine contained the same ingredients with the addition of 5.00% naturally smoked sugar. In the second study a natural control curing brine was utilized and contained 72.0% water, 13.4% sea salt, 8.00% cane sugar, and 6.67% celery juice. While treatment brine had the same ingredients as the natural control brine with the addition 5.00% smoked sugar. Bacon slices were randomly assigned to four sensory and GCMS frozen storage periods (0, 40, 80, and 120 day) or seven thiobarbituric acid reactive substances (TBARS) frozen storage times (0, 20, 40, 60, 80, 100, and 120 day). To measure lipid oxidation trained sensory evaluation, TBARS, and gas chromatography mass spectrometry (GCMS) was conducted after the assigned frozen storage periods. All bacon slices were stored aerobically at -18 ± 2 °C for their designated storage period. The first study panelist scores for oxidized flavor of the conventional control bacon increased from day 0 to 120; whereas the naturally smoked sugar treatment had decreased panelist scores (P > 0.16) for oxidized flavor intensity compared to the control bacon. Also, TBARS results values for the conventional control bacon increased (P < 0.01) from day 20 to day 120; while the conventional naturally smoked sugar treatment remained constant (P > 0.99). Hexanal content for conventional control increased (P < 0.003) during frozen storage; but naturally smoked sugar TBARS values were not different from day 0 of storage (P > 0.734). Concentration of heptanal in conventional control bacon was the highest (P < 0.003) at day 80 and 120 of frozen storage. Heptanal content in conventional bacon with naturally smoked sugar was not different from day 0 of frozen storage (P > 0.846). Conventional bacon formulated with naturally smoked sugar had greater concentrations of creosol and syringol than control bacon (P < 0.003). In the second study, naturally cured bacon had increased panelist scores for oxidized flavor from day 0 to 120 of frozen storage (P < 0.001). Natural bacon with smoked sugar had oxidized flavor scores that remained constant during frozen storage (P > 0.936). Naturally cured bacon displayed increased TBARS values from day 20 to 120 of frozen storage (P < 0.001). Naturally cured bacon with smoked sugar exhibited static TBARS values throughout the frozen storage period (P > 0.196). Thus, smoked sugar is an effective antioxidant in frozen sliced, aerobically packaged, conventionally cured and naturally cured bacon.

Glucocorticoids (Gcs) are a commonly used drug to target the glucocorticoid receptor (GR). The GR has a myriad of cellular and physiological effects, however, Gcs are clinically used for the treatment of inflammatory conditions due to the potent anti-inflammatory actions of GR. The anti-inflammatory effects come with serious side effects e.g. metabolic disease. I examine the role of lipid rafts in modulating the anti-inflammatory actions of Gcs, and the role of circadian rhythms in the control of Gc side effects. I tested the role of caveolin-1 (Cav1), a constituent of membrane lipid rafts, and its role in Gc suppression of inflammation. Gene expression analysis of mouse lung tissue showed that genetic depletion of Cav1 (CAV1KO) results in increased transactivation of Gc target genes. The increased Gc action, however, does not result in an increased effect on suppression of inflammation in a model of innate immunity: aerosolised lipopolysaccharide (LPS) induced lung inflammation or in a model of adaptive immunity: Ovalbumin. CAV1KO mice were protected from LPS induced inflammation, despite increased cytokine production. This suggests a differential response to LPS in lung parenchyma and alveolar macrophages dependent on Cav1. CAV1KO results in a pro-inflammatory phenotype in macrophages, and the opposite in parenchymal tissue. These data suggest that while Cav1 is an upstream regulator of Gc response, it does not have a strong enough effect to alter the ability of GR to repress inflammation in vivo. Gc treatment results in a strong metabolic phenotype, with aberrant energy metabolism, insulin resistance and hepatosteaotosis, I investigated how this side effect interacts with circadian rhythms, another key determinant of energy metabolism. Using transcriptomics of whole lung and liver taken during the day or the night, I demonstrate that the metabolic actions of Gc in the liver can be temporally separated, whilst maintaining consistent anti-inflammatory actions in both liver and lung. This temporal gene regulation by Gc is controlled by REV-ERB, a rhythmically expressed, orphan nuclear receptor, part of the core clock machinery, via a direct interaction with GR at key regulatory DNA loci. Genetic deletion of REV-ERB protects mice from the hepatosteotosis associated with Gc treatment. Taken together, these data suggest that Gcs are regulated upstream of the receptor by the core consitutent of membrane lipid rafts; Cav1, which modulates the Gc response in vivo. Also, that the GR action can be controlled by dosing at different times of day, separating the detrimental metabolic effects of Gcs from the beneficial anti-inflammatory effects. This is enabled through a direct interaction between GR and REV-ERB at key gene regulatory sites.

No presente trabalho, foram desenvolvidas nanocápsulas de núcleo lipídico (LNCs) para posterior revestimento com manana através da utilização de duas metodologias diferentes, sendo ambas por interações eletrostáticas. Na primeira metodologia, soluções de manana em diferentes concentrações foram gotejadas sobre a formulação LNC-Quit+ e na segunda metodologia a LNC-Quit+ foi injetada nas soluções de manana. Através de análises de diâmetro, mobilidade eletroforética, potencial zeta e viscosidade, foi possível notar que a primeira metodologia não apresenta reprodutibilidade, demonstrando valores aleatórios, ao passo que, na segunda metodologia os valores são reprodutíveis para a concentração de 0,5 μg/mL final de manana. Também foi possível observar que as nanopartículas revestidas com manana não apresentam estabilidade após 24 horas, sugerindo-se que a manana se desprende da superfície da partícula. Nas duas metodologias foram utilizadas concentrações diferentes de material de partida, e com isso, foi criada a metodologia 2B para que as anteriores pudessem ser comparadas. Com estes resultados tem-se um caminho promissor para estudos futuros e o aprimoramento deste tipo de revestimento. / In the present work, lipid core nanocapsules (LNCs) was developed for subsequent coating with mannan by using two different methodologies and both by electrostatic interactions. In the first methodology, mannan solutions at different concentrations were drop wise on LNC-Quit+ formulation and the second methodology, LNC-Quit+ was injected in mannan solutions. Through analysis of diameter, electrophoretic mobility, zeta potential and viscosity, it was possible to notice that the first methodology was not reproductible, showing random values, whereas, in the secont methodology the values was reproductible for the 0,5 μg/mL concentration. It was also possible to observe that the particle coated with mannan has no stability after 24 hours, suggesting that mannan detaches from the particle surface. In this methodologies, two different concentrations of raw materials are used, and with that, it was created the methodology 2B so that the results could be compared. With these results, it was a promising path way for future studies and enhancement of this type of coating.

The circadian clock system is essential for mammals to adapt to environmental conditions such as light-dark cycles and to manage the optimal timing for cyclical physiological processes, including sleep-wakefulness, fasting-feeding and multiple aspects of metabolism. The circadian timing system is arranged in hierarchical fashion, with the master clock in the suprachiasmatic nucleus (SCN) of the hypothalamus, acting as the pace-maker and maintaining synchrony among clocks found in every organ system throughout the body. The core molecular clock consists of two interconnected transcriptional-translational feedback loops comprising core clock components: Brain and Muscle Arnt-Like protein1 (BMAL1), Circadian Locomoter Output Cycles Kaput (CLOCK), Period (PER), Cryptochrome (CRY), Nuclear Receptor family1 D1 (REV-ERB) and Retinoic acid-related Orphan Receptor (ROR). Circadian clock disruptions, through environmental changes to light-dark cycles or through genetic modification of core clock genes cause metabolic disturbances. Aryl hydrocarbon receptor (AhR), also known as the dioxin receptor, mediates systemic metabolism and toxicity of a range of environmental contaminants. Epidemiological studies have established a positive correlation between exposure to dioxins and other synthetic organic chemicals and metabolic diseases such as diabetes and dyslipidemia. Animal research have supported these findings by showing that AhR activation has detrimental effects on glucose and lipid homeostasis. Mechanisms for AhR-mediated metabolic dysfunction remain unknown. Coincidently, both AhR and many core clock components, for example BMAL1 and CLOCK, belong to the basic helix-loop-helix/Per-Arnt-Sim (bHLH-PAS) domain family. Previous studies have linked AhR signaling to circadian rhythm. Importantly, activation of the AhR can impair transcriptional activity of the CLOCK: BMAL1 heterodimer in cultured cells. However, because the AhR is differentially expressed among the body’s tissues, its activation may have distinctive, tissue-specific effects on the hierarchical circadian clock oscillators in vivo, which have not been investigated. Therefore, this dissertation is designed to examine the short-term and long-term effects of AhR activation on circadian clocks and downstream clock-regulated metabolic pathways. Specifically, this dissertation is aimed to explore how acute and chronic activation of AhR affects rhythmic aspects of behavior, as well as clock-controlled glucose and lipid metabolism. In the acute AhR activation model, a single dose of the synthetic AhR agonist, β-Naphthoflavone (BNF), was administered to C57Bl/6J wild type mice. Circadian behavior was monitored before and after acute AhR activation. Circadian expression of core clock genes, as well as key metabolic genes in the liver, skeletal muscle and adipose tissue were examined. Compared to the vehicle group, BNF-treated mice displayed a transient loss of behavioral rhythmicity and delayed activity onset, which suggest that acute activation of AhR acts directly on the central clock, the suprachiasmatic nucleus of the hypothalamus. In contrast, circadian oscillations of core clock genes were not eliminated in the peripheral tissues (liver, skeletal muscle and adipose tissue), but changes were observed in their rhythmic amplitude or phase. Rhythms of key enzymes related to glucose and lipid metabolic pathways in the liver and adipose were decreased while those in the skeletal muscle were increased. These results indicate that acute AhR activation affects the central clock and peripheral clock differently. Moreover, acute AhR activation significantly dampened the rhythm of genes involved in lipogenesis, lipolysis and lipid storage. In the chronic AhR activation model, C57Bl6/J mice were exposed to BNF for a month to explore whether long-term AhR activation can cause bigger disruption of circadian clocks and lead to metabolic dysfunction in vivo. Unexpectedly, general circadian behavior was maintained although after each dose of BNF there was a consistent, transient loss of behavioral rhythmicity and significant phase delay (about 30 minutes) in BNF-treated mice. Liver and skeletal muscle clocks were not significantly altered after 4 doses of BNF, and the in-phase oscillations of core clock genes in liver and skeletal muscle suggested a functional SCN as well as the two peripheral clocks. However, the adipose clock was significantly disrupted. Altered clock-regulated rhythms in lipid metabolism genes are associated with impaired lipid storage functions in white adipose tissues and deregulated plasma lipids in BNF-treated mice. The results of acute and chronic AhR activation support a significant interaction of AhR with the circadian clock system. Although future studies are needed to elucidate how AhR signaling specifically interacts with the clock in different cell types, the current research establishes a model for studying the crosstalk between AhR and circadian rhythm and provides new perspectives into the mechanisms of metabolic diseases correlated with exposure to synthetic organic chemicals.

Introdução: A barreira hematoencefálica limita a penetração de compostos farmacologicamente ativos para o cérebro devido à presença de zônulas de oclusão no endotélio cerebral e a expressão de transportadores de influxo e efluxo que modulam o acesso de fármacos para o parênquima cerebral. Nanocápsulas de núcleo lipídico (LNC) tem sido estudadas como carreadores de fármacos para o tecido cerebral devido à capacidade de modulação da farmacocinética desses compostos. Entretanto, ainda pouco se sabe sobre os processos envolvidos nas alterações farmacocinéticas e na distribuição tecidual promovidas por esses transportadores. Objetivo: Pretendeu-se investigar as alterações na farmacocinética plasmática e penetração cerebral da quetiapina (QTP) nanoencapsulada em ratos Wistar. Materiais e Métodos: QLNC (1mg/mL) foram obtidas através da metodologia de nanoprecipitação e apresentaram reduzido tamanho de partícula (143 ± 6 nm), baixo indicie de polidispersão (PI < 0.1), alta eficiência de encapsulação (96%), potencial zeta negativo (-7.65 ± 0.815 mV) e pH ácido. QLNC quando visualizadas por MET apresentaram tamanho esférico, homogêneo com ausência de agregados. Os estudos in vivo desse trabalho foram aprovados pelo CEUA/UFRGS. Análise do plasma total e a utilização da microdiálise para determinação das concentrações plasmáticas e cerebrais livres foram realizadas após administração intravenosa da formulação de nanocápsulas de QTP (5 mg /kg ) (QLCN) ou do fármaco em solução (FQ) (5 mg /kg e 10 mg /kg) na presença e na ausência de 30 mg /kg de probenecida (PB), um inibidor de transportadores de membrana. Métodos validados foram utilizados para a quantificação do fármaco em diferentes matrizes. As concentrações cerebral e hepática totais foram investigadas através da técnica de homogeneizado de tecido. Além disso, a fração livre no plasma (fu) e a penetração nos eritrócitos também foi realizada. Resultados: QTP apresentou farmacocinética linear na faixa de doses investigadas, é um substrato para transportadores de efluxo na BHE. Diferenças foram observadas na fu da QTP até 2 h após administração de QLNC indicando que LNC do tipo III promove uma liberação sustentada do fármaco do carreador. QLNC não foi capaz de alterar o coeficiente de partição nos eritrócitos determinado in vitro. As concentrações cerebrais e hepáticas totais foram aumentadas após administração da formulação de nanocápsulas, porém, as concentrações cerebrais livres não foram alteradas em comparação com o QTP em solução. Após administração de PB o fator de penetração da QTP livre no cérebro foi reduzido de 1,55 ± 0.17 para 0,94 ± 0,15. Porém, essa inibição pela probenecida não teve efeito na penetração cerebral de QLNC (0,88 ± 0,21 – 0,92 ± 0.13) provavelmente devido ao fato da QTP ser carreada pela LNC e não estar disponível para interagir com transportadores. Conclusão: Considerando todos os resultados sugere-se que as LNC do tipo III carreiam a QTP através da circulação sistêmica até o parênquima cerebral. / Introduction: Blood-brain barrier (BBB) hinders the delivery of therapeutics to central nervous system due to the endothelial cells tight junctions, which restrict paracellular transport of substances, and the expression of influx and efflux transporters, which modulate drugs access to the brain. Lipid-core nanocapsules (LNC) have been proposed as drug carriers to improve brain delivery by modulating drug pharmacokinetics (PK). However, little in know about this modulation process and it is not clear whether the LCN carry the drug through the BBB or increase free drug penetration due to changes in the barrier permeability. Objective: The work aimed to investigate the alterations in the model drug quetiapine (QTP) plasma PK and brain penetration following nanoencapsulation into LNC (QLNC) using microdialysis. Methods: QLNC (1 mg.mL-1) were obtained by nanoprecipitation and presented small particle size (143 ± 6 nm), low polidispersion index (PI < 0.1), high incorporation efficiency (96%), negative zeta potential (–7.65 ± 0.815 mV) and acidic pH. TEM photomicrography showed spherically shaped particles and absence of aggregation. Animal studies approved by CEUA/UFRGS. Total plasma and free plasma and brain concentrations, last two determined by microdialysis, were analyzed after QLNC (5 mg/kg) and free drug (FQ – 5 and 10 mg/gk) i.v. dosing to Wistar rats alone or following probenecid (PB), an influx transporter inhibitor, i.v. administration (30 mg/kg). Drug was quantified in all matrices by validate LC/UV methods. Total brain and liver concentration after FQ and QLNC dosing were investigated in tissues homogenate. Furthermore, QTP free fraction (fu) in plasma and erythrocyte penetration were determined. Results: QTP presented linear PK in the dose range investigated and is substrate to influx transporters at the BBB. Differences observed on QTP fu up to 2 h after QLNC dosing indicate a drug slow release in the blood stream loaded into the LNC type III nanocarrier for this period of time. The LNC did not altered QTP erythrocytes partition coefficient. Total brain and liver concentrations were increased after QLNC dosing but free brain concentrations were not altered in comparison with FQ dosing. After PB dosing, QTP brain penetration was reduced from 1.55 ± 0.17 to 0.94 ± 0.15 when FQ was administered but the inhibition of influx transporters had no effect on QLNC brain penetration (0.88 ± 0.21 to 0.92 ± 0.13) probably because QTP is loaded into the LNC and not available to interact with transporters. Conclusions: Taking together these results suggested that LNC type III carries QTP in the blood stream and delivers the drug to the brain.

ML (MD-2-related lipid-recognition) domain containing proteins are recognized as immune-related molecules. They do not belong among well-studied proteins in ticks although their occurence is quite often. Generally, ML proteins are involved in innate immunity processes, lipid binding and transport. Usually, expression of tick ML domain containing proteins is induced by blood feeding. Two members of the ML protein family, ML-domain containing protein and Der-p2 allergen-like protein were isolated from Ixodes ricinus and characterized for the first time.

abstract: Engineered nanoporous substrates made using materials such as silicon nitride or silica have been demonstrated to work as particle counters or as hosts for nano-lipid bilayer membrane formation. These mechanically fabricated porous structures have thicknesses of several hundred nanometers up to several micrometers to ensure mechanical stability of the membrane. However, it is desirable to have a three-dimensional structure to ensure increased mechanical stability. In this study, circular silica shells used from Coscinodiscus wailesii, a species of diatoms (unicellular marine algae) were immobilized on a silicon chip with a micrometer-sized aperture using a UV curable polyurethane adhesive. The current conducted by a single nanopore of 40 nm diameter and 50 nm length, during the translocation of a 27 nm polystyrene sphere was simulated using COMSOL multiphysics and tested experimentally. The current conducted by a single 40 nm diameter nanopore of the diatom shell during the translocation of a 27 nm polystyrene sphere was simulated using COMSOL Multiphysics (28.36 pA) and was compared to the experimental measurement (28.69 pA) and Coulter Counting theory (29.95 pA).In addition, a mobility of 1.11 x 10-8 m2s-1V-1 for the 27 nm polystyrene spheres was used to convert the simulated current from spatial dependence to time dependence. To achieve a sensing diameter of 1-2 nanometers, the diatom shells were used as substrates to perform ion-channel reconstitution experiments. The immobilized diatom shell was functionalized using silane chemistry and lipid bilayer membranes were formed. Functionalization of the diatom shell surface improves bilayer formation probability from 1 out of 10 to 10 out of 10 as monitored by impedance spectroscopy. Self-insertion of outer membrane protein OmpF of E.Coli into the lipid membranes could be confirmed using single channel recordings, indicating that nano-BLMs had formed which allow for fully functional porin activity. The results indicate that biogenic silica nanoporous substrates can be simulated using a simplified two dimensional geometry to predict the current when a nanoparticle translocates through a single aperture. With their tiered three-dimensional structure, diatom shells can be used in to form nano-lipid bilayer membranes and can be used in ion-channel reconstitution experiments similar to synthetic nanoporous membranes. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2015

abstract: ABSTRACT Objective: The purpose of this randomized, placebo-controlled trial was to investigate the effect a daily coconut oil supplement (2 grams) would have on a common serum marker of systemic inflammation (C-reactive protein) and an indicator of oxidative stress (TBARS) when compared to the control group receiving a placebo capsule (white flour) in healthy, sedentary adults between the ages of 18-40 in Phoenix, Arizona. Design: This study was designed as secondary analyses of blood samples originally collected to study the effects of coconut oil supplementation on blood lipids and body composition. The original study consisted of 32 healthy, adult volunteers recruited from the Arizona State University campus in Phoenix, Arizona. Participants followed no food restrictions or special diets, exercised less than 150 minutes per week, had no diagnoses of chronic disease, were not taking statin medications, were non-smokers, and no female participants were pregnant. Participants were randomized into either the Coconut Oil group (CO) or the Placebo group (PL) at week 0, and baseline blood samples and anthropometric measurements were obtained. Each participant completed an 8-week protocol consisting of two supplement capsules daily (coconut oil or placebo). Final fasting blood samples and anthropometric measurements were taken at week 8. This study analyzed the blood samples for measurements of C-reactive protein (CRP) and thiobarbituric reactive substance (TBARS). Results: Eight weeks of 2 grams per day coconut oil supplementation, in comparison to placebo treatment, did not significantly reduce serum CRP ( -13% and +51% respectively, p=0.183) but did significantly increase TBARS ( +16% and -27% respectively, p=0.049). Conclusions: Coconut oil supplementation (2 g/day) may impact lipid peroxidation as indicated by an increase in plasma TBARS concentration. Future trials are necessary to corroborate these results using other indices of fatty peroxide formation. / Dissertation/Thesis / Masters Thesis Nutrition 2017

Made available in DSpace on 2014-06-11T19:28:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-01-20Bitstream added on 2014-06-13T20:57:40Z : No. of bitstreams: 1 santos_fk_me_arafcf.pdf: 504042 bytes, checksum: ff6921c63666c7dee3c57494e9ca1b8f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A esquistossomose é uma doença que atinge cerca de 200 milhões de pessoas no mundo todo. A alta incidência desta doença está ligada à falta de condições sanitárias, ao diagnóstico tardio e, principalmente, à falta de tratamento medicamentoso eficiente. O praziquantel é o fármaco de primeira escolha para o tratamento da esquistossomose. No entanto, falhas no tratamento com este fármaco e relatos de isolamento de S. mansoni tolerantes podem comprometer a eficiência do PZQ. Assim, o PZQ representa um fármaco em que pesquisas para melhorar as suas propriedades biofarmacêuticas são necessárias, pois apresenta baixa solubilidade em meio aquoso e biodisponibilidade baixa ou errática. O presente trabalho vê como finalidade desenvolver carreadores lipídicos nanoestruturados (NLC) contendo praziquantel empregando como sistema lipídico o monoestearato de glicerila (GMS) e o ácido oléico (AO) e como sistema tensoativo a associações de monoestearato de polioxietileno sorbitano 60 (TWEEN60), fosfatidilcolina, Poloxamer (Pluronic F-127 PLU). Os NLCs foram preparados através de dois diferentes métodos, de sonicação e alta velocidade de cisalhamento a quente. Os sistemas foram caracterizados através da avaliação dos parâmetros de distribuição de tamanho, potencial zeta, índice de polidispersidade e eficiência de encapsulação. O transporte intestinal do fármaco foi avaliado através do modelo do saco intestinal invertido. Ambos os métodos de obtenção empregados mostraram-se eficazes para o preparo dos NLCs em escala nanometrica, com índice de polidispersidade homogeneo e um... / The Schistosomiasis is a debilitating disease with high misfit in the quality of people life reached about 200 million people worldwide. The high incidence of this disease is linked to poor sanitary conditions, late diagnosis, and especially the lack of effective drug treatment. Praziquantel is the drug of first choice for treatment of schistosomiasis. However, treatment failures with this drug and reports of isolation of S. mansoni tolerance may compromise the efficiency of PZQ. Thus, the PZQ represents an example in which surveys to improve the biopharmaceutical properties are needed, since it has low solubility in aqueous and low or erratic bioavailability. This work aims to develop nanostructured lipid carriers (NLC) containing praziquantel employing as lipid system the glycerin monostearate (GMS) and oleic acid (OA) as a surfactant system and some combination of polyoxyethylene sorbitan monostearate 60 (TWEEN60), phosphatidylcholine and Poloxamer (Pluronic F-127 PLU) as a surfactant system. NLCs were prepared by two different methodologies, the sonication and high shear rates to warm. The systems were characterized by determination of size distribution, zeta potential, polydispersity index and encapsulation efficiency. The intestinal transport of the drug was evaluate by using the model of inverted intestinal sac. Both methods were effective for the preparation of NLCs with an average diameter in the nanometer range, the polydispersity index indicating homogeneity of particle size and a zeta... (Complete abstract click electronic access below)