Um estudo das propriedades ópticas do cromóforo hipocrelina B (HB) e de seus complexos com os íons lantânio (La3+), európio (Eu3+) e térbio (Tb3+) em soluções em etanol foi realizado. Tal pigmento enquadra-se como um promissor fotossensibilizador de segunda geração dadas suas ótimas propriedades, tais como rápido metabolismo in vivo e principalmente elevado rendimento quântico de geração de oxigênio singleto (FD). O presente trabalho foi desenvolvido em duas etapas: a primeira consistiu do estudo espectroscópico dos complexos de hipocrelina B (HB) com os íons lantanídeos (Ln3+), e a segunda, de testes de PDT in vitro em cultura do fungo Candida albicans. Na primeira etapa do trabalho, a melhor razão molar entre HB e Ln3+ foi verificada através do monitoramento do pico de absorção em maior comprimento de onda de cada um dos complexos. O maior deslocamento do pico de absorção da HB (de 589 nm para 614 nm) foi notado para os complexos com razão de 1 mol de HB para 2 mols de íon lantanídeo. Observou-se que a emissão da HB e de seus complexos ocorre desde cerca de 600 nm até 750 nm. Foi possível, com base nos espectros de absorção e de emissão, calcular os valores de níveis de energia da molécula e de seus complexos. Todos os fotossensibilizadores apresentaram como menor nível de energia valor superior a 0,98 eV, o que é um indício de sua capacidade de geração de oxigênio singleto. Foram determinadas as constantes de dimerização das amostras, de maneira a identificar sua tendência à formação de dímeros ou agregados de ordem superior, e os valores obtidos para a HB e seus complexos com lantânio, európio e térbio foram, respectivamente, de 4,7.104, 3,6.105, 2,1.105 e 1,0.105 M-1. Todas as amostras mostraram-se estáveis perante a ação de luz de 532 nm de até 400 mW/cm2 de intensidade pelo período de uma hora de irradiação. As capacidades de geração de oxigênio singleto das amostras foram determinadas tanto através do método espectroscópico direto (detecção da emissão do oxigênio singleto em torno de 1270 nm) quanto do método químico indireto (variações na absorção em 440 nm do composto RNO). Notou-se que para a HB o método direto indicou haver geração de oxigênio singleto, e o método químico revelou que esta espécie é gerada à taxa de 2,8.10-4 s-1; para HB:La3+ (1:1) obteve-se aumento de 32% na geração de oxigênio singleto em relação à HB, e para HB:La3+ (1:2), determinou-se taxa de 3,0.10-4 s-1 pelo método indireto. Com base nos dados experimentais obtidos, verificou-se que o melhor dentre os complexos estudados foi o HB:La3+ (1:2), sendo este e seu precursor HB então aplicados em testes de PDT antimicrobiana in vitro, constituindo a segunda etapa do trabalho. A concentração de HB ideal para trabalho obtida foi de 10 M. Notou-se eliminação total de microorganismos com apenas 30 segundos de irradiação com LED de 460 nm e intensidade de 333 mW/cm2 tanto para o complexo como para o seu precursor. Porém, com excitação em 660 nm com esta mesma intensidade, apenas HB:La3+ (1:2) se mostrou efetivo, chegando ao efeito fotodinâmico total após 6 minutos de irradiação; a redução causada pela HB no mesmo intervalo de tempo foi bem menos pronunciada, o que comprova a eficiência do fotossensibilizador produzido. / A study about the optical properties of the chromophore hypocrellin B (HB) and of its complexes with lanthanum (La3+), europium (Eu3+) and terbium (Tb3+) ions in ethanol solutions was realized. This pigment is a potential second generation photosensitizer due to its great properties, as high in vivo metabolism and mainly high singlet oxygen generation quantum yield (FD). The present work was carried out in two stages: the first one consisted of the spectroscopic study of the complexes of HB with lanthanide ions (Ln3+); the second one, of in vitro PDT tests against Candida albicans. In the first stage of the work, the best molar ratio between HB and Ln3+ was verified by monitoring the complexes longer wavelength absorption peaks. The larger red-shift (from 589 nm to 614 nm) was noted for the complexes with 1 mol of HB for 2 moles of lanthanide ions. It was observed that HB and its complexes emit from about 600 nm up to 750 nm. It was possible, from the absorption and emission spectra, to calculate the values of energy levels for the molecule and its complexes. All photosensitizers showed for the lower energy level value higher than 0,98 eV, which can indicate that they are able to generate singlet oxygen. The dimerization constants of the samples were determined, for verifying their tendency for giving rise to dimmers or higher order aggregates. The obtained values of this parameter for HB and its complexes with lanthanum, europium and terbium were, respectively, 4,7.104, 3,6.105, 2,1.105 and 1,0.105 M-1. All the samples showed to be stable against the action of light of 532 nm with intensity up to 400 mW/cm2 for the period of time of 1 hour. The capacities of generating singlet oxygen were determined by the direct (detection of the singlet oxygen emission around 1270 nm) and the indirect methods (changes in 440 nm absorption of RNO). The direct method indicated that HB can generate singlet oxygen, and the chemical method revealed that this specie is generated following a tax of 2,8.10-4 s-1; for HB:La3+ (1:1), it was obtained an enhancement of 32% on the singlet oxygen generation related to HB, and for HB:La3+ (1:2), the indirect method presented tax of 3,0.10-4 s-1. Based n the experimental data, the best among the studied complexes was HB:La3+ (1:2). Thus, this and its precursor, HB, were applied in antimicrobial PDT in vitro tests, the second stage of this work. The ideal concentration of HB was 10 M. With only 30 seconds of irradiation with LED in 460 nm and with 333 mW/cm2 of intensity, it was observed lethal effect for all the microorganisms, with both HB and its complex. However, with excitation at 660 nm at the same intensity, only HB:La3+ (1:2) was effective, reaching total photodynamic effect after 6 minutes of irradiation; the reduction caused by HB in the same time interval was lower, which proves the effectiveness of the produced photosensitizer.

A Terapia Fotodinâmica (TFD) é um tratamento alternativo de câncer que vem tendo grandes avanços ao longo dos anos e consiste na interação entre luz e uma substância fotossensibilizadora, levando à transformação do oxigênio molecular em oxigênio singleto, altamente reativo e tóxico para a célula. Nesse contexto, o uso do modelo de Membrana Corioalantóica (CAM, do inglês Chorioallantoic Membrane) fornece acesso direto aos vasos sanguíneos, possibilitando o estudo dos efeitos vasculares envolvidos nessa terapia. O desenvolvimento de um tumor nesse ambiente previamente vascularizado permite o estudo e o entendimento dos mecanismos que envolvem o crescimento e destruição do tumor, levando ao aperfeiçoamento de diferentes modalidades terapêuticas. As células tumorais empregadas para o desenvolvimento do tumor podem ser de diversas linhagens e formas de aplicação, desde culturas celulares a biópsias tumorais. O objetivo principal foi investigar a terapia fotodinâmica nos vasos e nas células neoplásicas em um modelo de tumor em CAM. Com esse modelo estudado para células tumorais de melanoma e Ehrlich, foi escolhido trabalhar com tumor de Erlich pela facilidade de manuseio laboratorial. Por meio da microscopia confocal de fluorescência, foi observada a interação entre os vasos sanguíneos e as células tumorais. Com imagens por fluorescência, foi possível entender e quantificar o efeito individualizado dos fotossensibilizadores, incluindo a farmacodinâmica do Photogem® e da formação da protoporfirina IX a partir do ALA, tanto com aplicação tópica como intravenosa. A partir disso, o tumor foi irradiado e os efeitos da terapia fotodinâmica foram analisados tanto no tumor quanto nos vasos sanguíneos que o alimentam. Usando ainda a curcumina, um fotossensibilizador derivado do açafrão, que sozinho possui um efeito vascular, foi aplicada a Terapia Fotodinâmica para análise na membrana corioalantóica e efeito nos vasos sanguíneos. O entendimento desse efeito da curcumina permite a ampliação de seu uso como fotossensibilizador no tratamento de câncer e doenças vasculares. Portanto, com o modelo estabelecido foi possível acompanhar os fotossensibilizadores estudados tanto nos vasos sanguíneos e sua ação, como a diferente atuação no ambiente tumoral, causando dano às células do tumor e aos vasos sanguíneos do mesmo ambiente. / Photodynamic Therapy (PDT) is a cancer treatment that has had great advances over the years and consists in the interaction between light and a photosensitizer compound, transforming the molecular oxygen in singlet oxygen, highly reactive and toxic to the cell. In this context, the use of Chorioallantoic Membrane (CAM) enables direct access to blood vessels, making possible to study the vascular effects involved in this therapy. The development of a tumor in this environment previously vascularized allows the study and the understanding of mechanisms that involves the growing and the destruction of tumor, improving different therapeutic modalities. The tumor cells used to develop the tumor in this model can be from several lines and ways of application, since cell culture to biopsy of some tumor. The main objective was investigating PDT in blood vessels and neoplasic cells in the tumor model in CAM. With this model studied for melanoma cells and Ehrlich, it was chosen to work with Ehrlich tumor because its facility of laboratory manipulation. After the observation the interaction between blood vessels and tumor cells, with confocal microscopy analysis, it was possible to understand and quantify the individualized effect of photosensitizers, including the pharmacodynamic of Photogem® and the Protoporphyrin IX from Aminolevulinic acid, both topic and intravenous application. From this, the tumor was illuminated and the Photdynamic Therapy effects was analyzed both tumor and blood vessels that feeds it. Still using the curcumin, photosensitizer derivated of saffron which has alone a vascular effect, was applied PDT to analysis on the Chorioallantoic Membrane and the blood vessels effect. The understanding of this effect of curcumin enables the extension of its useful as photosensitizer in the cancer treatment and vascular diseases. Therefore, with the model established, it was possible to follow all PS studying both their action in blood vessels and in the tumor region, causing damage.

Depuis une vingtaine d'années, la recherche dans le domaine des nanoobjets pour de l'imagerie et de la thérapie devient de plus en plus importante. En effet, les nanoparticules présentent de nombreux avantages par rapport aux composés moléculaires : leur temps de résidence dans le système sanguin est plus long ; la nanoparticule peut contenir une grande quantité de molécules actives ; les nanoparticules peuvent contenir plusieurs fonctionnalités grâce à leur multimodalité ; et elles peuvent s'accumuler dans les zones cibles grâce à un ciblage passif ou actif. Dans ce cadre, nous proposons une nouvelle structure hybride AGuIX® de taille inférieure à 5 nm, constituée d'une matrice de polysiloxane à la surface de laquelle sont greffés des complexes de gadolinium et des ligands libres. Ces nanoparticules ont été développées pour des applications en imagerie (IRM, scintigraphie, fluorescence) ainsi que des applications en thérapie (radiothérapie). Le but de la thèse consiste d'une part à maîtriser le mécanisme de synthèse, caractériser les nanoparticules par le développement de techniques originales et enfin à exploiter les propriétés multimodales de la nanoparticule afin de proposer plusieurs solutions en imagerie et en thérapie. Les tests biologiques montrent un fort potentiel des nanoparticules pour des applications biologiques. Dans un premier temps, les nanoparticules ont été couplées à des photosensibilisateurs afin d'induire un autre mode de thérapie : la PDT. Ce couplage a permis de travailler sur les mécanismes physiques opérant dans ce modèle. Afin de proposer une dualité en imagerie, les particules AGuIX® ont été marquées par différents isotopes radioactifs. Pour cela, la nanoparticule a été modifiée par l'ajout de ligands spécifiques complexant certains isotopes. Cette étude a abouti également sur le recherche d'un autre mode de thérapie possible avec les AGuIX® : la curie thérapie / Nanoparticles research has become one of the most promising way for biological applications. They present alternative solutions to the traditional diagnostic and therapeutic methods thanks to (i) their appropriate size and surface which can enhance circulation time in the blood, (ii) their large compartments able to contain considerable amounts of imaging or drugs agents, (iii) their multimodality which makes them potential multifunctional nanoplatforms for both diagnosis and therapy (theranostic), (iv) their capacity to target disease by their appropriate size and surface of by specific targeting moieties grafted on their surface. We propose a new sub-5 nanometer nanoparticles multimodal nanoparticle (called AGuIX®), composed of a polysiloxane network surrounded by gadolinium chelates and free chelates. They have previously demonstrated their efficiency for multimodal imaging and theranostic applications, especially MRI, scintigraphy and fluorescence imaging and radiotherapy. The aim of the thesis was to characterize the synthesis and the nanoparticles in order then to explore the multi-possibilities of therapy and imaging of these nanoparticles AGuIX®. Original characterizations technics were developed. The intrinsic measured properties of AGuIX® solutions fulfill the conditions for potential clinical applications, a wide series of biological tests have been performed. Then first, the coupling of the AGuIX® with another therapy method was explored: PDT effect with photosensitizers grafting on the surface of the nanoparticles. A good understanding of the mechanism was studied. The multimodality of imaging was tested by the labeling with radioactive elements on the surface of the nanoparticles. It was necessary to use a specific ligand in order to obtain high labeling yield. The coupling MRI/scintigraphy is one of the major field in order to have an imaging agent with high resolution and high sensitivity. This study was the opportunities to try to couple another therapy technic: brachytherapy

A terapia fotodinâmica (Photodynamic Therapy - PDT) é um método de tratar neoplasias baseado na interação entre luz, oxigênio molecular e um agente fotossensibilizador. Após a administração do agente, o tumor é iluminado com luz visível, ativando-o e produzindo espécies reativas de oxigênio, altamente citotóxicas, que provocam morte celular e destruição tecidual. Com a destruição do tumor há ativação do sistema imune inato e o subsequente processo inflamatório determina a apresentação de antígenos tumorais aos linfócitos, promovendo uma resposta imunológica adaptativa contra o tecido tumoral. O presente trabalho visou estudar a PDT associando um laser de diodo como fonte de luz e o fotossensibilizante Azul de Metileno (AM) a 1%, avaliando a sua efetividade no tratamento do Tumor de Ehrlich (TE) em sua forma sólida e a resposta imunológica nos animais tratados. Em um primeiro estudo, avaliou-se macro e microscopicamente tumores tratados, determinando a capacidade do protocolo em induzir inflamação e destruição do tecido tumoral. No segundo estudo, a resposta imune foi estudada em camundongos desafiados com um segundo implante de células do tumor de Ehrlich. O primeiro implante tumoral foi tratado com a PDT ou a excisão cirúrgica, comparando-se com um grupo controle sem tratamento. Os parâmetros avaliados após 17 dias foram o crescimento tumoral (p>0,05), peso relativo dos órgãos linfóides [Baço (p<0,05) e Linfonodo poplíteo (p>0,05)], tamanho relativo do linfonodo (p<0,05), presença de metástase em linfonodo poplíteo (p>0,05), contagem de leucócitos sanguíneos (p>0,05) e análise morfométrica quantitativa do tumor secundário [determinação da fração volumétrica de células tumorais (p<0,05), infiltrado inflamatório (p<0,05), necrose (p>0,06) e porcentagem da área tumoral em necrose (p<0,05)]. A PDT com o AM foi capaz de induzir necrose do TE e inflamação, havendo diferenças da resposta imune sistêmica quando comparado aos animais tratados por meio de excisão cirúrgica do tumor de Ehrlich. / Photodynamic therapy (PDT) is a method of treating neoplasms based on the interaction between light, molecular oxygen and a photosensitizing agent. After administration of the photosensitizer, the tumor is illuminated with visible light, activating the agent and producing reactive oxygen species (ROS). This highly cytotoxic ROS cause cell death and tissue destruction. The activation of the innate immune system and the subsequent inflammation induces tumor antigen presentation to lymphocytes, promoting an adaptive immune response against the tumor cells. This work aimed to study the PDT using a diode laser as light source and Methylene Blue (MB) 1% as photosensitizer. It was accessed its effectiveness in treating Ehrlich Solid tumor (ET) and the immune response produced in treated animals. First the treated tumors were evaluated macroscopically and microscopically, determining the ability of the protocol to induce inflammation and tumor tissue destruction. In a second study, the immune response was studied in mice challenged with a second tumor cell implant. The primary tumor was treated with PDT or surgical excision, comparing with a control group without treatment. The parameters evaluated after 17 days were tumor growth (p> 0.05), relative weight of lymphoid organs [spleen (p <0.05) and popliteal lymph node (p> 0.05)], the relative size of the lymph node (p <0, 05), metastasis at lymph node (p>0,05), blood leukocyte count (p> 0.05) and quantitative morphometric analysis of secondary tumor [determining the volume fraction of tumor cells (p <0.05), inflammatory infiltrate (p <0.05), necrosis (p> 0.06) and tumor necrosis area (p <0.05)]. PDT with MB was able to induce necrosis of the ET and inflammation, with differences in the immune response when compared to animals treated surgically to remove the Ehrlich tumor in its solid form.

A terapia fotodinâmica (Photodynamic Therapy - PDT) é um método de tratar neoplasias baseado na interação entre luz, oxigênio molecular e um agente fotossensibilizador. Após a administração do agente, o tumor é iluminado com luz visível, ativando-o e produzindo espécies reativas de oxigênio, altamente citotóxicas, que provocam morte celular e destruição tecidual. Com a destruição do tumor há ativação do sistema imune inato e o subsequente processo inflamatório determina a apresentação de antígenos tumorais aos linfócitos, promovendo uma resposta imunológica adaptativa contra o tecido tumoral. O presente trabalho visou estudar a PDT associando um laser de diodo como fonte de luz e o fotossensibilizante Azul de Metileno (AM) a 1%, avaliando a sua efetividade no tratamento do Tumor de Ehrlich (TE) em sua forma sólida e a resposta imunológica nos animais tratados. Em um primeiro estudo, avaliou-se macro e microscopicamente tumores tratados, determinando a capacidade do protocolo em induzir inflamação e destruição do tecido tumoral. No segundo estudo, a resposta imune foi estudada em camundongos desafiados com um segundo implante de células do tumor de Ehrlich. O primeiro implante tumoral foi tratado com a PDT ou a excisão cirúrgica, comparando-se com um grupo controle sem tratamento. Os parâmetros avaliados após 17 dias foram o crescimento tumoral (p>0,05), peso relativo dos órgãos linfóides [Baço (p<0,05) e Linfonodo poplíteo (p>0,05)], tamanho relativo do linfonodo (p<0,05), presença de metástase em linfonodo poplíteo (p>0,05), contagem de leucócitos sanguíneos (p>0,05) e análise morfométrica quantitativa do tumor secundário [determinação da fração volumétrica de células tumorais (p<0,05), infiltrado inflamatório (p<0,05), necrose (p>0,06) e porcentagem da área tumoral em necrose (p<0,05)]. A PDT com o AM foi capaz de induzir necrose do TE e inflamação, havendo diferenças da resposta imune sistêmica quando comparado aos animais tratados por meio de excisão cirúrgica do tumor de Ehrlich. / Photodynamic therapy (PDT) is a method of treating neoplasms based on the interaction between light, molecular oxygen and a photosensitizing agent. After administration of the photosensitizer, the tumor is illuminated with visible light, activating the agent and producing reactive oxygen species (ROS). This highly cytotoxic ROS cause cell death and tissue destruction. The activation of the innate immune system and the subsequent inflammation induces tumor antigen presentation to lymphocytes, promoting an adaptive immune response against the tumor cells. This work aimed to study the PDT using a diode laser as light source and Methylene Blue (MB) 1% as photosensitizer. It was accessed its effectiveness in treating Ehrlich Solid tumor (ET) and the immune response produced in treated animals. First the treated tumors were evaluated macroscopically and microscopically, determining the ability of the protocol to induce inflammation and tumor tissue destruction. In a second study, the immune response was studied in mice challenged with a second tumor cell implant. The primary tumor was treated with PDT or surgical excision, comparing with a control group without treatment. The parameters evaluated after 17 days were tumor growth (p> 0.05), relative weight of lymphoid organs [spleen (p <0.05) and popliteal lymph node (p> 0.05)], the relative size of the lymph node (p <0, 05), metastasis at lymph node (p>0,05), blood leukocyte count (p> 0.05) and quantitative morphometric analysis of secondary tumor [determining the volume fraction of tumor cells (p <0.05), inflammatory infiltrate (p <0.05), necrosis (p> 0.06) and tumor necrosis area (p <0.05)]. PDT with MB was able to induce necrosis of the ET and inflammation, with differences in the immune response when compared to animals treated surgically to remove the Ehrlich tumor in its solid form.

Cette étude concerne le développement d’un dispositif innovant de type biocapteur, pour le diagnostic et le traitement local de cancers précoces. Cette technologie vise à diagnostiquer au plus tôt certains cancers, afin de les traiter de façon beaucoup plus efficace, en comparaison avec les techniques actuelles, souvent longues et mutilantes. Des microplots de silice mésoporeuse, fonctionnalisés azotures, sont déposés par impression jet d’encre (IJP) à la surface de fibres optiques. Le matériau présente une porosité auto-organisée, grâce au mécanisme d’auto-assemblage induit par évaporation (EISA). Par la suite, les microplots azotures sont fonctionnalisés spécifiquement par chimie click (click chemistry) par reaction avec des molécules alcynes. Dans le cas du diagnostic, cette fonctionnalisation permet le greffage de protéines et d’anticorps capables de reconnaître les marqueurs surexprimés à la surface des cellules cancéreuses. Les protéines et anticorps sont préalablement marqués par des fluorochromes, pour induire un transfert d’énergie (effet FRET ou Fluorescence Resonance Energy Transfer) lors de la reconnaissance des marqueurs cancéreux. Le principe de détection du dispositif repose ainsi sur une modification de la signature de fluorescence. Dans le cas de la thérapie, des photosensibilisateurs (PS) sont greffés sur les microplots pour permettre un traitement local par photothérapie dynamique (PDT).L’objectif global de l’étude vise à améliorer la sensibilité de détection du dispositif pour le diagnostic et à montrer l’efficacité de traitement dans le cas de la thérapie. Pour cela, les protocoles de réaction click et de greffage des protéines ont été optimisés et l’influence de la structuration de la porosité a été étudiée. Enfin, la sensibilité du dispositif a été caractérisée en fonction de plusieurs paramètres (type de matériaux, type de cellules cancéreuses, etc.). / This study focuses on the development of a new biosensor device for the diagnosis and local treatment of precocious tumors. This technology aims to diagnose cancers at an early stage to increase the treatment efficiency compared to existing techniques that are usually damaging. Mesoporous silica microdots with azide functions are deposited onto the surface of optical fibers using the inkjet-printing (IJP) process. The material shows a self-organized porosity, due to the evaporation-induced self-assembly (EISA) mechanism. Then, the azide microdots can be further functionalized specifically using click chemistry by reaction with alkyne precursors. For the diagnosis, the functionalization allows the grafting of proteins and antibodies capable of recognizing the increase in marker concentration at the surface of cancerous cells. These proteins and antibodies are labelled with fluorophores to induce a fluorescence energy transfer (FRET, Fluorescence Resonance Energy Transfer) with the recognition of tumorous markers. The detection principle is based on the modification change of the fluorescence signature. For the therapy, photosensitizers (PS) are anchored onto the microdots to allow the local treatment using photodynamic therapy (PDT). The main aim of this study was to optimize the device sensitivity concerning the diagnosis step, and to show the treatment efficiency concerning the therapy step. On that purpose, the protocols of click reaction and the grafting of proteins have been optimized, which are also influenced by the porosity organization that has been studied. Finally, the device sensitivity has been characterized as a function of multiple factors (materials, cancer cells type, etc.).

Die Photodynamische Therapie (PDT) hat sich zunehmend als vielversprechende Methode zur Behandlung von verschiedenen malignen Neubildungen gezeigt. Die photodynamische Zerstörung der Tumore wird erreicht indem zunächst ein Photosensibilisator entweder lokal oder systemisch appliziert wird und im Anschluss an eine gewisse Inkubationszeit die Tumormasse mittels einer Lichtquelle mit einer spezifischen Wellenlänge durchleuchtet wird. Aufgrund der bevorzugten Anreicherung des Photosensibilisators in Tumorzellen, erlaubt diese Methode eine selektive Abtötung des malignen Tumors, während das umliegende Gewebe weitestgehend verschont wird. Diese Eigenschaften und Anforderungen machen die PDT, insbesondere in den Fällen, wo die chirurgische Enukleation als kurative Option erwogen wird, zu einer attraktiven Therapieoption in der Behandlung von Retinoblastomen (Rb). Die extreme Methode der Enukleation wird noch immer angewendet, wenn die Tumoren nicht ausreichend chemosensibel sind, oder wenn sich die Erkrankung aufgrund von unzureichendem Zugang zu medizinischer Versorgung bereits in einem fortgeschrittenen Stadium befindet. In dieser Studie haben wir zunächst In-Vitro-Untersuchungen mit dem neuen kationischen wasserlöslichen Photosensibilisator Tetrahydroporphyrin-Tetratosylat (THPTS) bezüglich seiner photodynamischen Wirkung auf WERI Rb-1 und Y79-Retinoblastomzellen durchgeführt. Dabei konnten wir zeigen, dass weder die Inkubation mit THPTS ohne anschließende Beleuchtung, noch die alleinige Beleuchtung zu einem signifikanten Effekt auf die Proliferation der Rb-Zellen führte. Die Kombination von THPTS mit anschließender Beleuchtung hingegen führte zu einem maximal zytotoxischen Effekt in den Tumorzellen. Darüber hinaus war die Phototoxizität in normalen Primärzellen des Pigmentepithels der Retina geringer, wodurch ein erhöhter phototoxischer Effekt von THPTS in Krebszellen gegenüber diesem normalen Zelltyp der Retina gezeigt werden konnte. Die vorliegenden Ergebnisse bilden eine ermutigende Grundlage für weiterführende in-vivo-Untersuchungen zum therapeutischen Potential dieses vielversprechenden Photosensibilisators mit der Aussicht auf eine potentiell kurative Therapie des Retinoblastoms unter Erhalt von Augapfel und Visus.

Ce travail de thèse est consacré à la synthèse de porphyrines fusionnées à des cycles imidazolium et à l’utilisation de ces derniers comme précurseurs de ligands carbènes N-hétérocycliques (NHC). Ces composés possèdent donc deux sites de coordination, interne (le macrocycle) et externe (le ligand NHC), permettant la synthèse de complexes dinucléaires. Cette étude est principalement axée sur la synthèse de métalloporphyrines conjuguées avec des complexes d’or(I) périphériques de type [(NHC)AuCl]. En vue d’application en thérapie photodynamique (PDT), la fonctionnalisation de ces complexes par des carbohydrates (mannose) a été réalisée par substitution des ligands chlorures des complexes d’or(I) périphériques. Les tests biologiques sur cultures cellulaires montrent une nette potentialisation des propriétés photodynamiques des photosensibilisateurs comportant des ligands mannoses liés à l’or(I). Suite à cette étude, la synthèse de porphyrines fusionnées à deux cycles imidazolium a été réalisée permettant pour la première fois la synthèse de complexes trinucléaires de type Au/M/Au (M = métal interne dans la porphyrine) possédant différentes géométries. Ces composés ont ouvert des perspectives intéressantes dans le but d’obtenir des photosensibilisateurs possédant deux groupements carbohydrates à leur périphérie. De plus, il a été mis en évidence que les complexes trinucléaires de type Au/Zn/Au peuvent être utilisés comme briques de construction moléculaires pour la synthèse de polymères organométalliques en vue d’applications en (photo)catalyse. / This PhD work is devoted to the synthesis of porphyrins fused to imidazolium rings and their use as precursors of N-heterocyclic carbene ligands (NHC). Therefore, these compounds possess two coordination sites, the internal (the macrocycle) and the external (the NHC ligand) ones, allowing the synthesis of dinuclear complexes. This study is mainly centered on the synthesis of metalloporphyrins conjugated with peripheral gold(I) complexes such as [(NHC)AuCl]. In view of applications in photodynamic therapy (PDT), the functionalization of these complexes by carbohydrates was achieved through the substitution of chloride ligands of peripheral gold(I) complexes. Biological tests on cell cultures show a clear potentialization of the photodynamic properties of the photosensitizers bearing mannose ligands bound to gold(I). Following this study, the synthesis of porphyrins fused to two imidazolium rings was achieved allowing for the first time the synthesis of trinuclear species such as Au/M/Au (M = inner metal in the porphyrin core) with different geometries. These compounds open interesting perspectives in view of obtaining photosensitizers having two carbohydrates at their periphery. Moreover, it was shown that trinuclear species such as Au/Zn/Au can be used as molecular building-blocks for the synthesis of organometallic polymers in view of applications in (photo)catalysis.

Made available in DSpace on 2014-07-29T16:17:34Z (GMT). No. of bitstreams: 1 dissertacao joaopaulo moreira.pdf: 663224 bytes, checksum: 57876aadced04d387b0c9ff1e9f03eae (MD5) Previous issue date: 2010-09-17 / This dissertation examines the actualization of some themes of labourist political culture during the process of the consolidation of democracy in Brazil. Considering the relation between memory and history, i studied Darcy Ribeiro&#8223;s political career and the role it played in the change of ownership and principles of labourism, allowing a new political synthesis, active in the 1990s. Accordingly, in the assessment of his politic experiences, since the 60's, i found that such experiences have become shareholders of this renewed political culture. His parliamentary activity, during the 90s, brought into the political debate the issues dear to the design of basic reforms of the 1960s, namely: national development, a republican project, and proposals on education and land reform. Thus, the political experiences of the years 1960 and 1990 were compared, in the light of the concept of political culture, aiming to demonstrate how to change ownership in conformity to a political project for Brazil. / Esta dissertação analisa a atualização de alguns temas da cultura política trabalhista, durante o processo de consolidação da democracia no Brasil. A partir das relações entre memória e história, investigou-se a trajetória política de Darcy Ribeiro e o papel que esta desempenhou na apropriação e mudança de princípios do trabalhismo, possibilitando uma nova síntese política, atuante na década de 1990. Nesse sentido, a avaliação das experiências políticas de Darcy Ribeiro, desde os anos 60, revelou que tais experiências tornaram-se patrimônio desta cultura política renovada. Sua atividade parlamentar, durante os anos 90, trouxe ao debate político os temas caros ao projeto de reformas de base dos anos de 1960, quais sejam: o nacional-desenvolvimentismo, um projeto republicano, as propostas na área da educação e a reforma agrária. Desse modo, as experiências políticas dos anos de 1960 e 1990 foram comparadas, sob a luz do conceito de cultura política, objetivando demonstrar a apropriação e a mudança como conformadoras de um projeto político para o Brasil.

Um estudo das propriedades ópticas do cromóforo hipocrelina B (HB) e de seus complexos com os íons lantânio (La3+), európio (Eu3+) e térbio (Tb3+) em soluções em etanol foi realizado. Tal pigmento enquadra-se como um promissor fotossensibilizador de segunda geração dadas suas ótimas propriedades, tais como rápido metabolismo in vivo e principalmente elevado rendimento quântico de geração de oxigênio singleto (FD). O presente trabalho foi desenvolvido em duas etapas: a primeira consistiu do estudo espectroscópico dos complexos de hipocrelina B (HB) com os íons lantanídeos (Ln3+), e a segunda, de testes de PDT in vitro em cultura do fungo Candida albicans. Na primeira etapa do trabalho, a melhor razão molar entre HB e Ln3+ foi verificada através do monitoramento do pico de absorção em maior comprimento de onda de cada um dos complexos. O maior deslocamento do pico de absorção da HB (de 589 nm para 614 nm) foi notado para os complexos com razão de 1 mol de HB para 2 mols de íon lantanídeo. Observou-se que a emissão da HB e de seus complexos ocorre desde cerca de 600 nm até 750 nm. Foi possível, com base nos espectros de absorção e de emissão, calcular os valores de níveis de energia da molécula e de seus complexos. Todos os fotossensibilizadores apresentaram como menor nível de energia valor superior a 0,98 eV, o que é um indício de sua capacidade de geração de oxigênio singleto. Foram determinadas as constantes de dimerização das amostras, de maneira a identificar sua tendência à formação de dímeros ou agregados de ordem superior, e os valores obtidos para a HB e seus complexos com lantânio, európio e térbio foram, respectivamente, de 4,7.104, 3,6.105, 2,1.105 e 1,0.105 M-1. Todas as amostras mostraram-se estáveis perante a ação de luz de 532 nm de até 400 mW/cm2 de intensidade pelo período de uma hora de irradiação. As capacidades de geração de oxigênio singleto das amostras foram determinadas tanto através do método espectroscópico direto (detecção da emissão do oxigênio singleto em torno de 1270 nm) quanto do método químico indireto (variações na absorção em 440 nm do composto RNO). Notou-se que para a HB o método direto indicou haver geração de oxigênio singleto, e o método químico revelou que esta espécie é gerada à taxa de 2,8.10-4 s-1; para HB:La3+ (1:1) obteve-se aumento de 32% na geração de oxigênio singleto em relação à HB, e para HB:La3+ (1:2), determinou-se taxa de 3,0.10-4 s-1 pelo método indireto. Com base nos dados experimentais obtidos, verificou-se que o melhor dentre os complexos estudados foi o HB:La3+ (1:2), sendo este e seu precursor HB então aplicados em testes de PDT antimicrobiana in vitro, constituindo a segunda etapa do trabalho. A concentração de HB ideal para trabalho obtida foi de 10 M. Notou-se eliminação total de microorganismos com apenas 30 segundos de irradiação com LED de 460 nm e intensidade de 333 mW/cm2 tanto para o complexo como para o seu precursor. Porém, com excitação em 660 nm com esta mesma intensidade, apenas HB:La3+ (1:2) se mostrou efetivo, chegando ao efeito fotodinâmico total após 6 minutos de irradiação; a redução causada pela HB no mesmo intervalo de tempo foi bem menos pronunciada, o que comprova a eficiência do fotossensibilizador produzido. / A study about the optical properties of the chromophore hypocrellin B (HB) and of its complexes with lanthanum (La3+), europium (Eu3+) and terbium (Tb3+) ions in ethanol solutions was realized. This pigment is a potential second generation photosensitizer due to its great properties, as high in vivo metabolism and mainly high singlet oxygen generation quantum yield (FD). The present work was carried out in two stages: the first one consisted of the spectroscopic study of the complexes of HB with lanthanide ions (Ln3+); the second one, of in vitro PDT tests against Candida albicans. In the first stage of the work, the best molar ratio between HB and Ln3+ was verified by monitoring the complexes longer wavelength absorption peaks. The larger red-shift (from 589 nm to 614 nm) was noted for the complexes with 1 mol of HB for 2 moles of lanthanide ions. It was observed that HB and its complexes emit from about 600 nm up to 750 nm. It was possible, from the absorption and emission spectra, to calculate the values of energy levels for the molecule and its complexes. All photosensitizers showed for the lower energy level value higher than 0,98 eV, which can indicate that they are able to generate singlet oxygen. The dimerization constants of the samples were determined, for verifying their tendency for giving rise to dimmers or higher order aggregates. The obtained values of this parameter for HB and its complexes with lanthanum, europium and terbium were, respectively, 4,7.104, 3,6.105, 2,1.105 and 1,0.105 M-1. All the samples showed to be stable against the action of light of 532 nm with intensity up to 400 mW/cm2 for the period of time of 1 hour. The capacities of generating singlet oxygen were determined by the direct (detection of the singlet oxygen emission around 1270 nm) and the indirect methods (changes in 440 nm absorption of RNO). The direct method indicated that HB can generate singlet oxygen, and the chemical method revealed that this specie is generated following a tax of 2,8.10-4 s-1; for HB:La3+ (1:1), it was obtained an enhancement of 32% on the singlet oxygen generation related to HB, and for HB:La3+ (1:2), the indirect method presented tax of 3,0.10-4 s-1. Based n the experimental data, the best among the studied complexes was HB:La3+ (1:2). Thus, this and its precursor, HB, were applied in antimicrobial PDT in vitro tests, the second stage of this work. The ideal concentration of HB was 10 M. With only 30 seconds of irradiation with LED in 460 nm and with 333 mW/cm2 of intensity, it was observed lethal effect for all the microorganisms, with both HB and its complex. However, with excitation at 660 nm at the same intensity, only HB:La3+ (1:2) was effective, reaching total photodynamic effect after 6 minutes of irradiation; the reduction caused by HB in the same time interval was lower, which proves the effectiveness of the produced photosensitizer.