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No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_CaracterizacaoFisicoQuimica.pdf: 7325059 bytes, checksum: 05c86c83cfb22a07e8853efa8d299d9e (MD5) Previous issue date: 2013 / A Indústria Farmacêutica utiliza polímeros em forma de nanopartículas em formulações de liberação controlada e vetorizada por possuírem baixo custo em relação a demais métodos de preparações de formas farmacêuticas, aparentemente não serem reconhecidos pelo sistema de defesa do organismo, proporcionar melhora da eficácia, diminuição da toxicidade e da dose de fármaco administrado. O sulfato de condroitina-co-Nisopropilacrilamida (SCM + NIPAAm) é um copolímero proposto para este fim, a partir da reação de um polímero sintético, o poli N-isopropilacrilamida (PNIPAAm), com características termossensíveis, com um natural, o Sulfato de Condroitina (SC), com características bioadesivas. Assim, a copolimerização pode ser capaz de somar estas propriedades e aperfeiçoar o seu uso como um veículo para liberação controlada. Este trabalho objetivou, portanto, realizar a caracterização fisico-quimica das partículas de sulfato de condroitina e Nisopropilacrilamida e do copolímero SCM+NIPAAm (2,5 % e 5%) e do SCM+PNIPAAm 2,5% e uma avaliação toxicológica parcial de um destes copolímeros que apresentar as melhores propriedades de um eficiente carreador de fármacos, selecionado a partir dos ensaios de caracterização físico-química. Para determinar a estrutura química dos sistemas particulados e analisar os seus componentes químicos, foi realizada a Espectroscopia de Ressonância Magnética Nuclear (RMN) e Espectroscopia do Infravermelho com Transformada de Fourrier (FTIR); Para analisar a morfologia das partículas, foi usado a Microscopia Eletrônica de Varredura (MEV); A Termogravimetria/ Termogravimetria Derivada e Análise Térmica Diferencial (TG/DTG) foi usada para avaliar o comportamento térmico dos sistemas particulados, bem como auxiliar na análise de Cinética de Degradação (CD, método de Flynn-Wall-Ozawa); Foi ainda realizado a técnica de degradação in vitro e a determinação carga superficial e tamanho de partículas (análise do Potencial Zeta, PZ). Para avaliar a toxicidade, foi realizado o bioensaio em microcrustáceo Artemia salina (24 e 48 h), viabilidade celular (citotoxicidade) em células PC-12 (método do MTT) e também a toxicidade aguda oral em camundongos. As análises de RMN, FTIR e MEV demonstraram semelhança quanto ao aspecto estrutural e morfológico entre os copolímeros estudados. As análises de TG demonstraram que o SCM+NIPAAm 5% apresentou maior estabilidade térmica em relação aos demais copolímeros avaliados, uma vez que sua decomposição polimérica ocorre em temperaturas superiores, em torno de 233ºC. O DTA demonstrou valores de temperaturas concordantes com os eventos térmicos de decomposição apresentados pelas curvas das análises TG. Sua estabilidade foi confirmada através da CD e estudo de degradação in vitro, apresentando, respectivamente, Ea > 100 kJ mol-1 e perda de 48% da sua massa inicial após três meses. Além disso, SCM+NIPAAm 5% apresentou diâmetro de partícula inferior a 200 nm e índice de polidispersão de 0,35, além do PZ > -30mV, caracteristicas de um promissor candidato a carreador de fármacos. Em relação às avaliações toxicológicas, o SCM+NIPAAm 5% não apresentou toxicidade no bioensaio de A. salina (CL50> 1000) e no modelo celular avaliado, dentro das concentrações e circunstâncias de exposição estudadas. O SCM+NIPAAm 5%, na dose oral de 2000 mg/kg, não apresentou nenhum sinal evidente de toxicidade em camundongos, o que foi corroborado pela ausência de alterações anatomo-histopatológicas. A copolimerização do Sulfato de Condroitina e N-isopropilacrilamida na concentração estudada, dada suas características físico-químicas e toxicológicas preliminares, apresenta propriedades que contribuem para a proposta de um sistema que constitui uma nova forma de liberação controlada, especialmente de fármacos. / The pharmaceutical industry uses polymers as nanoparticles in controlled release formulations and vector for having low cost compared to other methods of preparation of pharmaceutical dosage forms, apparently not being recognized by the body's defense system, provide improved efficacy, reduce toxicity and the dose of administered drug. The sulfate of chondroitin-co-N-isopropylacrylamide (SCM + NIPAAm) is a copolymer proposed for this purpose, from a synthetic polymer reaction, poly Nisopropylacrylamide (PNIPAAm) with thermosensitive characteristics with a natural, Chondroitin sulfate (CS), with bioadhesive characteristics. Thus, the copolymerization may be able to add these properties and to improve its use as a vehicle for controlled-release. This study aimed to characterize physico-chemical of sulfate chondroitin particles and N-isopropylacrylamide and SCM+NIPAAm copolymer (2.5% and 5%) and SCM+PNIPAAm 2.5% and a partial toxicological evaluation of one of these copolymers presenting the best properties of an efficient carrier of drugs, selected from the trials of physic-chemical characterization. To determine the chemical structure of the particulate systems and analyze the chemical components, it was performed Nuclear Magnetic Resonance Spectroscopy (RMN) and Infrared Fourier Transformed Spectroscopy (FTIR), to analyze the morphology of the particles, it was used Electron Microscopy (SEM), The Thermogravimetry and Differential Thermal Analysis (TG/DTA) was used to evaluate the thermal behavior of particulate systems, as well as assist in the analysis of kinetics of degradation (CD, Flynn-Wall-Ozawa method); it was also made in vitro degradation technique and surface charge determining and particles size (Zeta potential analysis, PZ). To evaluate the toxicity, it was performed bioassay in Artemia salina (24 and 48 hours), cell viability (cytotoxicity) on PC-12 cells (MTT method), and also acute oral toxicity in mice. The NMR, FTIR and SEM analysis showed similarity regarding the structural and morphologic aspects between the studied copolymers. TG analyzes showed that SCM+NIPAAm 5% showed higher thermal stability compared to the other copolymers evaluated, since its polymer decomposition occurs at temperatures above around 233 °C. DTA demonstrated temperature values consistent with decomposition thermal events provided by the curves of TG analysis. The stability was confirmed by CD and in vitro degradation study, presenting, respectively, Ea> 100 kJ mol-1 and 48% of its initial weight after three months. Furthermore, SCM+NIPAAm 5% presented particle diameter of less than 200 nm and polydispersity index of 0.35, and the PZ> -30mV, characteristics of a promising candidate as a drug carrier. Regarding toxicological evaluations, SCM+NIPAAm 5% did not show toxicity on bioassay A. saline (LC50> 1000) and in the cellular model evaluated within the concentrations and circumstances of exposure studied. The SCM+NIPAAm 5%, in the oral dose of 2000 mg/kg, did not show any obvious sign of toxicity in mice, which was confirmed by the absence of anatomical and histopathological changes. The copolymerization of chondroitin sulfate and N-isopropylacrylamide in the studied concentration, given its physical-chemical characteristics and toxicological preliminary, presents properties that contribute to propose a system which is a new form of controlled release, especially drugs.

Yung, Him Shun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 133-146). / Abstracts in English and Chinese. / Abstract --- p.i / 論文摘要 --- p.iv / Acknowledgements --- p.vi / Publications based on work in this thesis --- p.vii / Abbreviations --- p.viii / Contents --- p.xi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Objectives and overview of this study --- p.1 / Chapter 1.2 --- Rat pheochromocytoma (PC12) cells --- p.3 / Chapter 1.3 --- Prostanoids and their receptors --- p.4 / Chapter 1.4 --- Roles of prostanoids --- p.7 / Chapter 1.5 --- Nerve growth factor (NGF) and its receptors --- p.9 / Chapter 1.6 --- Change of gene expressions by NGF in PC12 cells --- p.10 / Chapter 1.7 --- Signaling pathways involved in NGF-induced differentiation of PC12 cells --- p.12 / Chapter 1.8 --- Classification of adenylyl cyclases --- p.14 / Chapter 1.9 --- Methods to study differentiation of PCI 2 cells --- p.15 / Chapter Chapter 2 --- Materials and Methods --- p.19 / Chapter 2.1 --- Materials --- p.19 / Chapter 2.2 --- Cell culture medium and buffers --- p.25 / Chapter 2.3 --- Buffers and solutions for assay of [3H]inositoI phosphates ([3H]IP) production --- p.25 / Chapter 2.4 --- Buffers and solutions for assay of [3H]cAMP production --- p.27 / Chapter 2.5 --- Buffers and solutions for Western blotting --- p.28 / Chapter 2.6 --- Methods --- p.30 / Chapter 2.6.1 --- Maintenance of PC12 cells --- p.30 / Chapter 2.6.2 --- General culture condition of PCI2 cells for NGF treatment --- p.31 / Chapter 2.6.3 --- Determination of phospholipase C activity in PC12 cells --- p.31 / Chapter 2.6.3.1 --- Principle of assay --- p.31 / Chapter 2.6.3.2 --- Column preparation --- p.32 / Chapter 2.6.3.3 --- Measurement of [3H]IP production --- p.33 / Chapter 2.6.3.4 --- Data analysis --- p.34 / Chapter 2.6.4 --- Determination of adenylyl cyclase activity in PC12 cells --- p.35 / Chapter 2.6.4.1 --- Principle of assay --- p.35 / Chapter 2.6.4.2 --- Column preparation --- p.35 / Chapter 2.6.4.3 --- Measurement of [3H]cAMP production --- p.36 / Chapter 2.6.4.4 --- Data analysis --- p.37 / Chapter 2.6.5 --- Determination of neurofilament protein expression in PC12 cells by Western blotting --- p.38 / Chapter 2.6.6 --- Determination of adenylyl cyclase isoform expression in PC12 cells by reverse transcriptase-polymerase chain reaction (RT-PCR) --- p.39 / Chapter 2.6.6.1 --- Isolation of total cellular RNA --- p.39 / Chapter 2.6.6.2 --- Synthesis of first strand cDNA by reverse transcription (RT) --- p.40 / Chapter 2.6.6.3 --- Polymerase Chain Reaction (PCR) --- p.41 / Chapter 2.6.6.4 --- Agarose gel electrophoresis --- p.41 / Chapter 2.6.7 --- Neurite quantification --- p.42 / Chapter 2.6.8 --- Trypan blue exclusion test --- p.42 / Chapter Chapter 3 --- Results --- p.45 / Chapter 3.1 --- Characterization of prostanoid receptor expression in PC12 cells . --- p.45 / Chapter 3.1.1 --- Study of the presence of Gq-coupled prostanoid receptors --- p.45 / Chapter 3.1.2 --- Study of the presence of Gs-co»pled prostanoid receptors --- p.47 / Chapter 3.1.3 --- Study of the presence of Gi-coupled prostanoid receptors --- p.48 / Chapter 3.1.4 --- Further proof of EP3 expression in PC12 cells --- p.50 / Chapter 3.1.5 --- Discussion --- p.51 / Chapter 3.2 --- Time course effect of NGF on PC12 cells --- p.65 / Chapter 3.2.1 --- Effect of NGF on PGE2-mediated inhibition of forskolin-stimulated [3H]cAMP production --- p.65 / Chapter 3.2.2 --- Effect of NGF on basal and forskolin-stimulated [3H]cAMP production --- p.67 / Chapter 3.2.3 --- Acute effect of NGF on [3H]cAMP production --- p.70 / Chapter 3.2.4 --- Effect of NGF withdrawal on basal and forskolin-stimulated [3H]cAMP production --- p.71 / Chapter 3.2.5 --- Effect of NGF on adenylyl cyclase gene expression --- p.72 / Chapter 3.2.6 --- Discussion --- p.74 / Chapter 3.3 --- Quantification of the degree of differentiation of PC12 cells --- p.89 / Chapter 3.3.1 --- Expression of neurofilament protein as a marker of differentiation --- p.89 / Chapter 3.3.2 --- Neurite assays --- p.90 / Chapter 3.3.2.1 --- Manual assessment of PC12 cells --- p.90 / Chapter 3.3.2.2 --- Quantification of images of PC1 2 cells --- p.91 / Chapter 3.3.3 --- Discussion --- p.93 / Chapter 3.4 --- Adenosine A2a receptor activity in PC12 cells --- p.106 / Chapter 3.4.1 --- Effect of NGF on A2Areceptor-mediated [3H]cAMP production --- p.106 / Chapter 3.4.2 --- Synergistic activation of adenylyl cyclase by A2A receptor and forskolin --- p.108 / Chapter 3.4.3 --- Chronic and acute effect of ADA and ZM241385 on [3H]cAMP production --- p.109 / Chapter 3.4.3.1 --- Chronic effect of ADA and ZM241385 --- p.110 / Chapter 3.4.3.2 --- Acute effect of ADA and ZM241385 --- p.111 / Chapter 3.4.4 --- Discussion --- p.112 / Chapter Chapter 4 --- Discussion and future perspectives --- p.121 / Chapter 4.1 --- Discussion --- p.121 / Chapter 4.2 --- Future perspectives --- p.131 / References --- p.133

Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves: 138-170). Also available on the Internet.

This work focuses on anorexigenic neuropeptides, cocaine- and amphetamine-regulated transcript (CART) and prolactin-releasing peptide (PrRP), which decrease food intake and body weight. CART peptide is an anorexigenic neuropeptide and, despite many efforts, its receptor has not yet been identified. We found CART peptide specific binding sites in pheochromocytoma PC12 cells. Cells differentiated to neurons increased significantly the number of binding sites. On the other hand, after differentiation to chromaffin cells the number of binding sites was so low that it was impossible to determine their density. To clarify the importance of each of the three disulfide bridges in the CART molecule, analogs with one or two disulfide bridges were synthetized. The biological activity was maintained in analog with two disulfide bridges in positions 74-94 and 88-101. Moreover, we demonstrated the stimulation of JNK and subsequently c-Jun activation in PC12 cells. Neuropeptide PrRP belongs to the RF-amide peptide family and has anorexigenic properties. PrPR has a high affinity to GPR10 and neuropeptide FF (NPFF2) receptor. In our laboratory lipidized analogs of PrRP were synthesized, which are able to decrease food intake after peripheral administration and may cross the blood-brain barrier. We tested biological...

This work focuses on anorexigenic neuropeptides, cocaine- and amphetamine-regulated transcript (CART) and prolactin-releasing peptide (PrRP), which decrease food intake and body weight. CART peptide is an anorexigenic neuropeptide and, despite many efforts, its receptor has not yet been identified. We found CART peptide specific binding sites in pheochromocytoma PC12 cells. Cells differentiated to neurons increased significantly the number of binding sites. On the other hand, after differentiation to chromaffin cells the number of binding sites was so low that it was impossible to determine their density. To clarify the importance of each of the three disulfide bridges in the CART molecule, analogs with one or two disulfide bridges were synthetized. The biological activity was maintained in analog with two disulfide bridges in positions 74-94 and 88-101. Moreover, we demonstrated the stimulation of JNK and subsequently c-Jun activation in PC12 cells. Neuropeptide PrRP belongs to the RF-amide peptide family and has anorexigenic properties. PrPR has a high affinity to GPR10 and neuropeptide FF (NPFF2) receptor. In our laboratory lipidized analogs of PrRP were synthesized, which are able to decrease food intake after peripheral administration and may cross the blood-brain barrier. We tested biological...

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19759号 / 農博第2155号 / 新制||農||1039(附属図書館) / 学位論文||H28||N4975(農学部図書室) / 32795 / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 植田 充美, 教授 宮川 恒, 教授 栗原 達夫 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Le but de ce mémoire est de valider la microscopie électro-optique Pockels comme méthode de mesure et de cartographie de champ électrique aux échelles micro et nanométriques. Une première partie est dédiée à la description de l’instrumentation d’imagerie mise en jeu. Nous développons ensuite son application en physique et biophysique. Une étude de couches minces monocristallines de 2-methyl-4-nitroaniline (MNA) a permis de sonder localement la variation de champ électrique appliqué, mais aussi d’étudier l’orientation des axes optiques de ce cristal dans l’espace. A l’échelle sub-longueur d’onde nous avons pu isoler la modulation électro-optique de la diffusion de lumière associée à une nanoparticule isolée de KTiOPO4 (KTP) d’une taille de 150nm. La dépendance polaire du signal Pockels sur la polarisation lumineuse incidente a permis de prédire l’orientation de la maille cristalline du KTP dans l’espace. De telles sondes de champs électriques nanométriques peuvent avoir de nombreuses applications en nano-photonique. Dans le cas d’entité biologiques comme des neurones, la propagation de l’information est assurée par celle d’un champ électrique dans les membranes plasmiques. Dans une première étape, nous nous sommes intéressés à l’étude de bicouches artificielles dopées par un colorant non-linéaire, le DI-8-ANEPPS. Un signal électro-optique Pockels y a été mesuré pour la première fois. La caractérisation de l’insertion du colorant dans la membrane a été aussi discutée. La grande sensibilité à la mesure d’un champ électrique assurée par l’interféromètre permet d’envisager des possibilités d’applications dans des cellules vivantes. Des expériences menées sur des cellules de type PC12 ont montré l’existence d’un signal optique qui est associé à la distribution spatiale du champ électrique. L’ensemble de ces travaux montrent que la microscopie électro-optique s’avère constituer un outil important pour la physique et biophysique. / The aim of this thesis is to validate the electro-optical Pockels microscopy as a powerful technique for electric field imaging at nano and micrometer scales. A first part of this manuscript is dedicated to the instrumental aspects of this new microscope modality. Then we discuss its application in physical and biophysical domains. We have investiguqted 2-methyl-4-nitroaniline(MNA) monocrystalline molecular thin films where the electric field distribution could be imaged, and crystal orientation retrieved. At sub-wavelength scale, we were able to isolate the electro-optical modulation of light scattered by isolated 150nm size KTiOP04 (KTP) nanoparticles. Using the angular dependency of the Pockels response to the polarization of light we could determine the a priori random, spatial orientation of the nanocrystal. Such electric-field nano-probe configuration could find its way in various applications. In the case of biological entities such as neurons, information is transmitted via an electric field signal, propagating through the plasmid membrane. We concentrated first on a model artificial membrane doped with the DI-8-ANEPPS nonlinear dye, evidencing for the first time a Pockels electro-optical response. A relatively high sensitivity to the electric field allows to envision interesting applications in living cells. Experiences performed with PC 12 cells have shown an optical response that reflects the electric field spatial distribution. This work demonstrates that the electro-optical microscopy is emerging as a new powerful tool for sub-wavelength investigation of electro-optical properties in physics and biology.

No description available.

<p>Protein tyrosine kinases play an important role in the regulation of various cellular processes such as</p><p>growth, differentiation and survival. GTK, a novel SRC-like cytoplasmic tyrosine kinase, was recently cloned from a mouse insulinoma cell line and the present work was conducted in order to find a biological function of GTK in insulin producing and neuronal cells. It was observed that kinase active GTK-mutants, expressed in RINm5F cells, transferred to the cell nucleus and increased the levels of the cell cycle regulatory protein p27^KIP1, reduced cell growth and stimulated glucagon mRNA expression. Furthermore, wild type GTK induces neurite outgrowth in the rat adrenal pheochromocytoma PC12 cell line, through activation of the RAP1-pathway, suggesting a role of GTK for cell differentiation. Studies using transgenic mice, expressing GTK under the control of the rat insulin 1 promoter, demonstrated a dual role of GTK for β-cell growth: Whereas GTK increases the β-cell mass and causes enhanced β-cell proliferation in response to partial pancreatectomy it also induced β-cell death in response to proinflammatory cytokines and impaired the glucose tolerance in mice treated with the β-cell toxin streptozotocin suggesting a possible role of GTK for β-cell destruction in Type 1 diabetes. We have also observed that GTK-transgenic islets and GTK-expressing RINm5F cells exhibit a reduced insulininduced activation of the insulin receptor substrate (IRS-1 and IRS-2)-pathways, partly due to an increased basal activity of these. GTK was found to associate with and phosphorylate the SH2 domain adapter protein SHB, which could explain many of the GTK-dependent effects both in vitro and in vivo. In summary, the present work suggests that the novel tyrosine kinase GTK is involved in various signal transduction pathways, regulating different cellular responses, such as proliferation, differentiation and survival.</p>

<p>Formation of blood vessels occurs through two processes: vasculogenesis and angiogenesis, which are regulated by various growth factors such as vascular endothelial growth factor, fibroblast growth factor and platelet-derived growth factor. The present study was carried out in order to investigate the roles of the Shb and Cbl proteins in growth factor-mediated signal transduction and blood vessel formation. Shb was found to be involved in NGF-stimulated Rap1 signaling in PC12 cells by forming a complex with CrkII and a 130-135 kDa protein. The Rap1 signaling pathway contributed to NGF-dependent neurite outgrowth. In immortomouse brain endothelial (IBE) cells, Shb increased cell spreading, migration and cytoskeletal rearrangements. Such effects may partly be due to altered Rap1 activation in Shb overexpressing IBE cells. Shb was required for tubular morphogenesis in collagen gels in the presence of FGF-2. In embryoid bodies (EBs) derived from murine embryonic stem cells, Shb up-regulated both VEGFR2 and Tal1 expression at early stages of EB development and thus promoted blood vessel formation both in the absence and in the presence of growth factors. In IBE cells, Cbl positively regulated FGF-2 signaling and increased cell proliferation. Mutation of RING finger alone did not affect blood vessel formation in EBs. However, EBs overexpressing the oncogenic form Cbl 70Z, which had a deletion of the linker region and the first cysteine of the RING finger, exhibited intense CD31 positive sheet-like staining and blood vessel. The results suggested that Cbl had dual roles in endothelial cells: it promoted FGF-2-induced proliferation whereas down-regulated proliferation of endothelial progenitor cells.</p><p>The present work suggests that Shb and Cbl play a crucial role in cell differentiation and blood vessel formation.</p>