The thesis "Inflation targeting in circumstances of low interest rates" describes the monetary policy of the Czech National Bank with main aim on its current problems. The target of the thesis is to analytically prove the disruption of a section of the transmission mechanism when the repo rate should determine the interest rates on the czech interbank market. This disruption should have been caused by the recent financial crisis.

The main goal of this work is to recognise if there is any connection between the advertisement targeted to children and their eating habits.

The main goal of this thesis has been a study of alternative policy rules in a small structural model calibrated to capture the Czech economy. After the overview of the historic development of economic theory and structural modeling we have specified a small open economy model that has served as a main technical tool for the analysis. The model represents a framework, where forward-looking model-consistent expectations are formed with respect to the development of the exchange rate and interest rates. Inflation expectations are forward looking too with some nominal rigidities in inflation dynamics. The model's structure is relatively simple. The IS curve captures the dynamics of real GDP, that exhibits real rigidity, motivated by habit formation or investment adjustment costs. In our specification the real GDP is a function of (the deviation of) real XR, real IR and foreign demand (from corresponding equilibrium levels). The Phillips-curve is based on the F-M type wage setting behavior, therefore it enables to consider domestic prices, that are modeled as mark-ups over wages. CPI inflation then consists of domestic, imported and administered inflation, including the effect of any indirect taxes changes. The exchange rate is modeled by the UIP arbitrage condition. Exchange rate expectations are forward-looking, but with some inertia in expectation formation. Interest rates with one year maturity are also modeled as an arbitrage condition on the money market, they are fully model-consistently forward looking. The model is closed by a Taylor-type forward-looking policy rule. The interest rate exhibits some inertia and feeds back from deviation of inflation from target and output from its equilibrium. The specification (parameterization) of the rule is general enough to examine CPI and domestic inflation targeting. The model specification has been followed by empirical work leading towards the implementation of the previously specified model on Czech data. Based on the sources of the Czech Statistical Office, Czech National Bank, Consensus Economics Inc., we first processed the data by executing seasonal adjustment and other transformations necessary for being consistent with the definition of model variables. The database has been created by an automatic MATLAB based routine, therefore the calculations were relatively easy to update. The database being completed, we have set up a Kalman-filter for determining equilibrium values for the real interest rate, exchange rate and output. At the same time through Kalman filtering we identified all model residuals. We paid special attention to the decomposition of the output gap and discussing In order to assess the overall dynamic properties of the model and judge how well the model fits the data, we conducted several exercises. First we decomposed some of the important endogenous variables of the model to shocks to see, whether the identified shocks are in line with our intuition and episodes of the recent Czech economic history. We found, that the shocks are not in contrast with some of the clearly distinguishable episodes. After the shock decomposition we run in-sample simulations to see, how well the model is able to fit the reality two years ahead. We found the overall results quite encouraging. We were able to fit quite well the output gap as well as MP inflation. Domestic inflation has been slightly more inertial in model simulations than in reality, but even in this case the results were acceptable. The model was not able to fit the 2001-2 appreciation of the nominal XR footnote{Understandably it neither forecasted well the fast fall in inflation after the appreciation period.}, which is not a big surprise. The model calibration part of the thesis concludes, that the model fits the data and economic story reasonably well.

The illegal targeting of healthcare in armed conflict is nothing new but its continuance and impunity at a time when the protection of it has formally never been higher, for instance through the UNSC Resolution 2286, motivated this study. Therefore, the thesis analyses how the illegal targeting of healthcare affect humanitarian actors operating in Yemen as well as the local population. How the population and humanitarian actors perceive and interpret the violent targeting of healthcare was explored as well.    This study is based on a quantitative and qualitative content analysis of 11 media outlets and 25 documents provided by humanitarian actors. As a theoretical framework the humanitarian principles, international humanitarian law and the politicisation of humanitarian aid were addressed. Moreover, securitization theory was used in order to explain how humanitarian actors securitize the targeting through language. The results show that consequences of the illegal targeting for humanitarian organisations are limited access to the field as well as the closing of facilities and withdrawal of staff due to security issues. For the Yemeni population consequences are a limited access to healthcare as well as a loss of trust in the safety of medical facilities and therefore they often take the decision to not seek medical care. The analysis shows that humanitarian actors present the illegal targeting as a threat to the survival of beneficiaries and connect this to their own organisational survival and through that securitize the illegal targeting.

In 2007, the Student Equity and Talent Management Unit (SETMU) at the University of the Witwatersrand (Wits) initiated a programme called the Targeting Talent Programme (TTP). One of the objectives of the TTP is to equip students to be successful at university. The first cohort of students consisted of 270 talented Grade 9 students from disadvantaged rural and urban schools. They were identified at the end of 2006, and they attended enrichment sessions at the University during 2007, 2008 and 2009. Thirty seven of the students enrolled for Engineering at Wits in 2010. They were given no further assistance by the TTP. The TTP based the planning of its curriculum on the Competencies identified by the Programme for International Student Assessment (PISA). The primary aim of the PISA assessment is to determine the extent to which young people have acquired the wider knowledge and skills in reading, mathematical and scientific literacy that they will need in adult life, hence the TTP attempted to incorporate the PISA Competencies in their curriculum in order to equip students for tertiary education. Habits of Mind identified by Cuoco and others were also used in planning the TTP curriculum in order to equip students with thinking skills. The TTP was successful in helping students to achieve university entrance, but there is a need to investigate to what extent the three year intervention program enables the students to succeed at university. This report focuses on the 37 students who enrolled for Engineering at Wits in 2010. They are compared to a sample of 37 students from the 2010 cohort who did not attend the TTP. The sample of non-TTP students was chosen by matching the National Senior Certificate Mathematics and Science marks obtained by the ex-TTP students as closely as possible. Thus two samples with an almost identical initial academic profile were created. One of the differences between the samples is that the ex-TTP students had had input which was aimed at equipping them to attain university entrance and to succeed there, whereas the other students had had no such formal assistance. The ex-TTP students were also compared with the cohort as a whole. This report shows that 16 of the 37 students (43%) passed the Mathematics, Mechanics and Physics courses that they were enrolled for. It also shows that the ex-TTP students scored lower on average than the non-TTP students and the cohort, for the Mathematics, Physics and Mechanics courses that they were enrolled for. Interviews with 9 of the ex-TTP students show that they did not consciously transfer study techniques from the TTP to university. The TTP was thus only partially successful in its objective of enabling students to be successful at university.

Les nanoparticules de Gemcitabine-Squalène (Gem-Sq), synthétisées suivant le concept de « squalénisation », ont montré des activités anticancéreuses très supérieures à celles obtenues en présence de Gem libre. Néanmoins, leur PEGylation, c’est-à-dire leur décoration par du poly(éthylène glycol)-squalène (PEG-Sq) pour augmenter leur temps de demi-vie plasmatique, s’est avérée infructueuse du fait d’une déstructuration colloïdale. Par ailleurs, aucune stratégie de fonctionnalisation pour effectuer un ciblage actif de cellules cancéreuses, n’est à ce jour disponible. Au cours de cette thèse, nous avons donc cherché à résoudre ces problèmes. Après une étude bibliographique portant sur la conception de nanoparticules de prodrogues lipidiques, dans le but d’établir un constat récent de l’état de l’art dans ce domaine, nous avons proposé une voie de synthèse pour obtenir des nanoparticules multifonctionnelles (i.e., thérapeutique, fluorescentes et ciblées) à base de Gem-Sq, et ce par co-auto-assemblage des composés conjugués de Rhodamine-Sq, Gem-Sq et Biotin-Sq. Ces nanoparticules ont montré une internalisation plus importante dans les cellules cancéreuses et une meilleure efficacité thérapeutique que les nanoparticules de Gem-Sq non-fonctionnalisées. Dans un deuxième temps, nous avons apporté une solution au problème de la PEGylation des nanoparticules de Sq via la synthèse et l’utilisation de composés conjugués de type Gem-poly(méthacrylate de squalène). Ces prodrogues macromoléculaires ont été synthétisées par polymérisation radicalaire contrôlée et plus précisément par la technique RAFT. Les nanoparticules obtenues par auto-assemblage en solution aqueuse sont stables et présentent des activités anticancéreuses importantes sur différentes lignées cellulaires. Leur PEGylation par ajout de Sq-PEG durant la formulation s’est avérée possible et n’a pas conduit à une déstabilisation colloïdale. Enfin, j’ai participé à l’élaboration d’une nouvelle famille de nanoparticules de prodrogues macromoléculaires qui a consisté à faire croitre de courtes chaines de polyisoprène (PI) à partir de la Gem, donnant ainsi des conjugués de type Gem-PI, capables de s’auto-assembler sous la forme de nanoparticules avec une activité anticancéreuse in vitro et in vivo. / Gemcitabine-Squalene (Gem-Sq) nanoparticles have been synthesized from the “squalenoylation” approach and have shown superior anticancer activities compared to those obtained with free Gem. However, their PEGylation, that is their coating with poly(ethylene glycol)-squalene (PEG-Sq) in order to increase their circulation time, has been unsuccessful, leading to colloidal disassembly. In addition, to the best of our knowledge, there is not functionalization strategy yet available to perform active targeting against cancer. During this PhD thesis, we have been looking for solutions to tackle these two important problems. After a littérature survey about the design of lipidic prodrug nanoparticles, in order to establish a pretty accurate picture of the domain, we have reported a synthetic approach towards multifunctional Sq-based nanoparticles (i.e., therapeutic, fluorescent and targeted), through the co-self-assembly of the different Sq-based materials; that is Rhodamine-Sq, Gem-Sq and Biotin-Sq. These nanoparticles have demonstrated a greater internalization into cancer cells and a greater therapeutic effect than non-functionalized Gem-Sq nanoparticles. In the next step, we have provided a solution to the PEGylation issue by synthetizing Gem-poly(squalenoyl methacrylate) macromolecular prodrugs. These materials have been prepared by controlled/living radical polymerization and especially the RAFT technique. The resulting nanoparticles exhibited significant anticancer activities against various cancer cells and can be successfully PEGylated by the addition of Sq-PEG during their formulation. Eventually, I have participated to the design of a new family of macromolecular prodrugs obtained from the growing of short polyisoprene (PI) chains from Gem, leading to Gem-PI nanoparticles after self-assembly of Gem-PI. The nanoparticles led to significant anticancer activity both in vitro and in vivo.

Des progrès récents dans l’utilisation préclinique et clinique des petits ARN interférents (siRNA) ont montré leur potentiel en tant qu’inhibiteur de la synthèse protéique dans de nombreuses pathologies comme le cancer. L’administration des siRNA rencontre un certain nombre de problèmes liés à leur dégradation rapide dans les milieux biologiques, ainsi qu’à leur difficulté à pénétrer au sein des cellules cibles en raison de leur hydrophilie et de leur charge négative. Une des clés de l’amélioration de l’efficacité thérapeutique de ces molécules repose sur l’emploi de vecteurs. Au cours de cette thèse, des lipoplexes capables de protéger les siRNA contre la dégradation et de favoriser leur transport jusqu’aux cellules cibles ont été développés et optimisés. Pour ce faire, des lipoplexes recouverts d’HA ont été formulés pour la vectorisation active de siRNA vers des cellules tumorales surexprimant le récepteur CD44. Dans la première partie de cette thèse, la formation des lipoplexes a été étudiée, ainsi que les paramètres influençant leur organisation supramoléculaire. L'insertion de l'HA dans la structure du liposome au moment de la formation des vésicules a entraîné une augmentation de la taille des liposomes en fonction de la concentration d’HA. Leur complexation avec les siRNA a encore augmenté la taille des particules obtenues. L’ajout des acides nucléiques lors de la formation des lipoplexes a provoqué un déplacement d'une partie du conjugué HA-DOPE de la structure des lipoplexes, comme montré par électrophorèse capillaire. La titration calorimétrique isotherme et les études de diffraction des rayons X ont démontré que, sous l’effet des interactions électrostatiques avec les siRNA, un réarrangement des bicouches lipidiques a lieu, conduisant à la formation de vésicules oligolamellaires, confirmé visuellement par cryo-microscopie. Enfin, le positionnement convenable de l’HA sur la surface des lipoplexes et sa capacité de se lier spécifiquement aux récepteurs de CD44 ont été démontrés par la technique de résonance plasmonique de surface. Dans la deuxième partie de cette thèse, la capture cellulaire et localisation intracellulaire des lipoplexes-HA ont été évalués par cytométrie en flux et microscopie de fluorescence, et ont montré que les lipoplexes modifies par l’HA sont internalisés plus rapidement que les lipoplexes non modifiés, et une fois dans des cellules, ils sont localisés principalement à l’intérieur des endosomes. La capacité des lipoplexes à transporter des molécules de siRNA intactes au cytoplasme a été confirmée par 81 % d'inhibition d'expression de luciferase in vitro sur la lignée cellulaire de cancer du poumon A549-luc. In vivo, le traitement avec les lipoplexes-HA transportant un siRNA anti-luciferase a mené à une diminution statistiquement significative de l’expression de luciferase, ce qui a été confirmé par la réduction de l'expression d’ARNm de la luciferase dans le poumon des animaux traités avec les lipoplexes-HA. L'analyse de la distribution des lipoplexes dans les poumons a montré que les lipoplexes modifiés par l’HA sont distribués de façon plus importante et plus homogène dans le tissu pulmonaire que les lipoplexes non modifiés. Dans la troisième partie de cette thèse, la diffusion des lipoplexes-HA de siRNA dans le mucus a été étudié, afin d’évaluer la faisabilité de l’administration pulmonaire de ces particules. Les études utilisant la technique de « multiple particle tracking (MPT) » ont montré que la présence d’HA combinée à l'ajout de siRNA ont permis l’obtention de deux formulations de lipoplexes présentant une pénétration efficace dans le mucus, les lipoplexes-HA and les lipoplexes-PEG/HA. En conclusion, un système efficace de lipoplexes utilisant siRNA pour l'inhibition de l'expression génique ciblant les récepteurs CD44 a été développé. Les résultats obtenus confirment que les HA-lipoplexes sont capables de libérer efficacement le siRNA dans le cytoplasme des cellules in vitro et in vivo. / Recent progresses in the preclinical and clinical use of small interfering RNA (siRNA) have shown their potential as an inhibitor of protein synthesis in many diseases such as cancer. The administration of siRNA encounters a number of problems related to their rapid degradation in biological media, and their difficulty in penetrating targeted cells due to their hydrophilicity and negative charge. A key to improving the therapeutic efficacy of these molecules is based on the use of vectors. In this thesis, lipoplexes that can protect siRNA against degradation and facilitate their transport into target cells were developed and optimized. To do this, lipoplexes covered with HA were formulated for active vectorization of siRNA to tumor cells overexpressing the receptor CD44.In the first part of this thesis, the formation of lipoplexes was studied, and the parameters influencing their supramolecular organization. Insertion of HA within the liposome structure during vesicle formation resulted in the increase in liposome size as a function of HA concentration. Their complexation with siRNA has further increased the size of the particles obtained. The addition of siRNAs when forming lipoplexes caused a displacement of a portion of the HA-DOPE conjugate from the lipoplexes structure, as shown by capillary electrophoresis. The isothermal titration calorimetry and X-ray diffraction studies showed that a rearrangement of the lipid bilayers occur under the effect of electrostatic interactions with siRNAs, leading to the formation of oligolamellar vesicles, which was visually confirmed by cryo-microscopy. Finally, the proper positioning of the HA on the surface of the lipoplexes and its ability to specifically bind to the CD44 receptors has been demonstrated by the surface plasmon resonance technique.In the second part of this thesis, cellular uptake and intracellular localization of HA-lipoplexes were assessed by flow cytometry and fluorescence microscopy, and showed that lipoplexes modified by HA are internalized more rapidly than unmodified lipoplexes, and once in the cells, they are mainly localized within the endosomes. The ability of lipoplexes to transport intact siRNA molecules to the cytoplasm was confirmed by 81% of luciferase in vitro expression inhibition on the lung cancer cell line A549-luc. In vivo, treatment with HA-lipoplexes carrying anti-luciferase siRNA led to a statistically significant decrease in expression of luciferase, which was confirmed by reducing the mRNA expression of luciferase in lungs of animals treated with HA-lipoplexes. The analysis of the distribution of lipoplexes in the lungs showed that lipoplexes modified with HA are distributed more evenly in the lung tissue than unmodified lipoplexes.In the third part of this thesis, the movement of siRNA HA-lipoplexes in the mucus was studied to assess the feasibility of administering these particles directly to the lungs. Studies using the technique of "multiple particle tracking (MPT)" showed that the presence of HA combined with the addition of siRNA allowed the preparation of two lipoplexes formulations with efficient mucus-penetration, HA-lipoplexes and PEG/HA-lipoplexes.In conclusion, an efficient siRNA lipoplex system for inhibiting gene expression targeted TO the CD44 receptorS has been developed. The results confirm that the HA-lipoplexes are able to effectively release in vitro and in vivo the siRNA molecules in the cytoplasm of cells.

O regime de metas de inflação é uma estratégia de política monetária utilizada por inúmeros países desenvolvidos e em desenvolvimento que tem por objetivo ancorar as expectativas dos agentes econômicos quanto ao comportamento futuro da taxa de inflação. De acordo com a literatura sobre o tema, o regime de metas inflacionárias além de provocar efeitos positivos sobre a taxa de inflação das economias que o adotam, tende também a provocar melhoras sobre o comportamento do produto. O objetivo desta dissertação é analisar empiricamente os impactos da adoção do sistema de metas de inflação para a taxa de inflação e crescimento real do produto dos países, diferenciando os impactos entre os países desenvolvidos e os em desenvolvimento. Utilizando o grupo de países que adotam metas de inflação como o grupo de tratamento e os países que não adotam como grupo de controle, dois procedimentos metodológicos foram realizados: estimação por diferenças em diferenças e análise em painel. Os resultados da estimação por diferenças em diferenças não se mostraram robustos e assim a análise em painel foi realizada. Os resultados demonstram que a adoção do sistema de metas inflacionárias produz impactos significativos para a inflação e crescimento do produto dos países que o adotam. Para o caso dos países desenvolvidos a adoção do sistema de metas tende a elevar a taxa média de inflação assim como o crescimento do produto. Para os países em desenvolvimento, aqueles que adotam o regime tendem a apresentar médias de inflação e do crescimento do produto significativamente menores que os países que não adotam. Concluí-se que para os países em desenvolvimento existe um custo de manutenção do sistema de metas de inflação em termos de queda do crescimento do produto. Esse custo estaria relacionado à maior dificuldade enfrentada por tais países na construção de credibilidade, fazendo com que os mesmos sigam políticas monetárias restritivas e definam um desenho rígido para o regime de metas de inflação. / Inflation targeting is a monetary policy strategy used by several developed and developing countries which aims to link together the economic actors? expectation related to the future behaviour of the inflation rate. According to specialized literature, inflation targeting tends to bring an improvement over product behaviour, besides bringing positive effects over inflation rates of those countries that make use of it. The focal point of this dissertation is to empirically analyse the impacts caused by the adoption of inflation targeting system on countries? inflation rate and real GDP growth, distinguishing effects on developed countries from those on developing ones. Defining the group made of countries that do use inflation targeting as treatment group and the group made of countries that do no use it as control group, two methodological procedures were accomplished: differences-in-differences estimation and panel data analysis. As the results of differences-in-differences estimator did not seem robust, panel analysis was also consummated. These results showed that inflation targeting adoption causes significative impacts on inflation rate and GDP growth in countries that adopt it. In developed countries, the adoption of such monetary policy strategy tends to increase the mean inflation rate, which also occurs with the GDP growth. In the other hand, developing countries that adopted inflation targeting tend to present mean inflation rate and GDP growth substantially lower than developing countries that do not make use of it. Though, it is possible to conclude that exists a maintenance cost of inflation targeting system for developing countries regarding the loss in GDP growth. This cost could be related to the greater difficulty that these countries face when forming credibility, which forces them to follow restrictive monetary policies and also to define an strict outline for inflation targeting.

Em estudos prévios, mostramos que uma nanoemulsão lipídica (LDE) é reconhecida e se liga aos receptores de LDL após sua injeção na corrente sanguínea. Como tais receptores estão superexpressos em células com altas taxas de proliferação, como ocorre no câncer e na aterosclerose, a LDE pode ser utilizada como veículo para direcionar fármacos a essas células, diminuindo sua toxicidade e aumentando sua eficácia terapêutica. Anteriormente, reportamos que o tratamento com um derivado do paclitaxel, o oleato de paclitaxel, associado à LDE (PTX-LDE), reduziu em 60% a área lesionada de aortas de coelhos submetidos à dieta aterogênica, comparados a animais não tratados. No presente trabalho, avaliamos o efeito da associação de sinvastatina, medicamento hipolipemiante, e PTX-LDE, sobre a aterosclerose induzida por dieta em coelhos. Trinta e seis coelhos machos da raça Nova Zelândia foram submetidos à dieta enriquecida com 1% de colesterol durante oito semanas. A partir da quinta semana, os animais foram divididos em quatro grupos, de acordo com o tratamento: controle (solução salina EV), sinvastatina (2mg/kg/dia, VO), paclitaxel (PTX-LDE, 4mg/Kg/semana, EV), ou combinação de sinvastatina (2mg/Kg/dia, VO) com paclitaxel (PTX-LDE, 4mg/Kg/semana, EV). Após oito semanas, os animais foram sacrificados para análise das aortas. Em comparação aos controles, a área lesionada das aortas foi em torno de 60% menor, tanto no grupo paclitaxel, quanto no grupo da combinação, e em torno de 40% menor no grupo sinvastatina (p<0,05). A razão entre as camadas íntima/média foi menor nos grupos tratados, em relação ao grupo controle (controles, 0,35±0,22, sinvastatina, 0,10±0,07, paclitaxel, 0,06±0,16 e combinação, 0,09±0,05, p<0,0001). Os grupos combinação e sinvastatina apresentaram um aumento da porcentagem de colágeno nas lesões (combinação, 20% e sinvastatina, 22%), em comparação aos controles (11%) e ao grupo paclitaxel (12%), (p<0,0001). Houve uma diminuição da porcentagem de macrófagos na lesão em todos os grupos tratados (paclitaxel, 11%, sinvastatina, 8% e combinação, 5%), comparados ao grupo controle (30%), (p<0,0001). O grupo paclitaxel apresentou menor porcentagem de células musculares lisas na lesão (20%) em relação aos controles (33%), (p<0,0001), já na combinação, houve aumento dessa porcentagem (44%), (p<0,0001). A combinação com sinvastatina não aumentou a eficácia do tratamento com PTX-LDE na redução da área de lesões ateroscleróticas, porém, os efeitos adicionais sobre o perfil lipídico e na composição das lesões, observadas com o uso da combinação, são achados importantes, que sugerem benefícios no sentido de aumentar a estabilidade das placas ateroscleróticas, o que nos abre um caminho de pesquisa muito promissor. / In previous studies we have shown that a lipid nanoemulsion (LDE) is recognized and binds to LDL receptors after injection into the bloodstream. As those receptors are upregulated in cells with higher proliferation rates, as occurs in cancer and atherosclerosis, LDE can be used as a vehicle to direct drugs to those cells, diminishing toxicity and increasing therapeutic efficacy. Previously, we reported that treatment with antiproliferative agent paclitaxel derivative, paclitaxel oleate, associated with LDE (PTX-LDE), reduced by 60% the injured area of the aorta of rabbits subjected to atherogenic diet compared to untreated animals. In the current study we aim to test the effect of a combination of lipid-lowering drug simvastatin with PTX-LDE on diet-induced atherosclerosis in rabbits. Thirty-six male New Zealand rabbits were fed a 1% cholesterol diet for 8 weeks. Starting from week 5, animals were divided into four groups, according to the following treatments: controls (I.V. saline solution injections), simvastatin P.O. (2mg/kg/day), paclitaxel (PTX-LDE I.V. injections, 4mg/Kg/week), or paclitaxel-simvastatin combination (PTX-LDE I.V., 4mg/Kg/week + simvastatin P.O., 2mg/Kg/day). After 8 weeks, the animals were sacrificed for aorta evaluation. Compared to controls, the injured area was reduced by 60% in both paclitaxel and combination groups, and by 40% in simvastatin group (p<0,05). The intima/media ratio was reduced in treated groups, compared to control group (controls, 0,35±0,22, simvastatin, 0,10±0,07, paclitaxel, 0,06±0,16 and combination, 0,09±0,05, p<0,0001). Simvastatin and combination groups showed increased collagen content within the lesions (simvastatin, 22% and combination 20%), compared to controls (11%) and to paclitaxel group (12%), (p <0.0001). Macrophage content within the lesions was reduced in all treated groups (paclitaxel, 11%, simvastatin, 8% e combination, 5%), compared to controls (30%), (p <0.0001). The percentage of smooth muscle cells in the lesions was diminished in paclitaxel group (20%) compared to control group (33%), while the combination group showed increased percentage (44%) of smooth muscle cells in the lesions (p<0,0001). The combination of simvastatin did not improve the efficacy of the treatment with PTXLDE in reducing the area of atherosclerotic lesions, but the additional effects on lipid profile and lesion composition observed with the use of the combination are important findings that suggest benefits in order to enhance the stability of atherosclerotic plaques, which may lead us to a very promising research path.

Uma nova alternativa para o tratamento do câncer foi proposta em estudos anteriores, consistindo no uso de uma nanoemulsão lipídica como transportadora de agentes quimioterápicos às células neoplásicas. A redução da toxicidade da quimioterapia promovida pelo direcionamento específico de quimioterápicos às células tumorais nos levou a testar o potencial de aplicação do sistema de nanopartículas lipídicas na terapêutica combinada do paclitaxel com a sinvastatina, um agente hipolipemiante que pode ser empregado como coadjuvante no tratamento do câncer. Nos dias 11, 14 e 19 após a inoculação de células de melanoma B16F10, camundongos C57BL/6J receberam pela via intraperitoneal soluções de oleato de paclitaxel associado à nanoemulsão lipídica 17,5&#181;mol/kg (Nano-paclitaxel), formulação comercial do paclitaxel 17,5&#181;mol/kg, nanoemulsão lipídica (Nanoemulsão) e solução salina (Controle). A sinvastatina 50mg/kg/dia foi administrada por gavagem do 11° ao 19° dia após a inoculação do tumor em um dos grupos de animais tratados com o Nano-paclitaxel (Nano-paclitaxel + Sinva), no grupo tratado com a formulação comercial do paclitaxel (Paclitaxel + Sinva) e como monoterapia (Sinva). Camundongos Balb-c saudáveis receberam os mesmos tratamentos para avaliação dos possíveis efeitos tóxicos dos diferentes tratamentos. A terapia combinada Nano-paclitaxel + Sinva apresentou toxicidade negligível em comparação com a terapia combinada Paclitaxel + Sinva que provocou perda de peso e mielossupressão nos animais. Nos animais portadores de tumor, o tratamento Nano-paclitaxel + Sinva inibiu 95% do crescimento tumoral, comparado à inibição de 44% promovida pelo tratamento Paclitaxel + Sinva. Além disso, apenas 37% dos animais portadores de melanoma submetidos ao tratamento com Nano-paclitaxel + Sinva apresentaram metástases, em contraste com 90% dos tratados com Paclitaxel + Sinva. A probabilidade de sobrevida também foi maior nos camundongos tratados com o Nano-paclitaxel + Sinva em comparação aos tratados com Paclitaxel + Sinva. A análise de amostras de tumores por citometria de fluxo mostrou que somente nos grupos de animais tratados com Sinva, Nano-paclitaxel ou com a combinação Nano-paclitaxel + Sinva houve aumento na expressão de p21 em comparação ao grupo Controle. Da mesma forma, apenas nos grupos Sinva e Nano-paclitaxel + Sinva houve redução na expressão de ciclina D1 em comparação ao grupo Controle. O teste de viabilidade celular com rodamina 123 mostrou despolarização da membrana mitocondrial com redução no número de células tumorais viáveis em todos os grupos de tratamentos em comparação aos grupos Nanoemulsão e Controle. A avaliação histológica dos tumores demonstrou que os grupos Nanoemulsão e Controle apresentaram alta densidade de células tumorais, diferentemente dos demais grupos de tratamento e que apenas os tumores do grupo Nano-paclitaxel + Sinva apresentaram aumento na presença de fibras de colágeno tipo I e III. Em comparação ao grupo Controle, os tumores dos grupos Sinva, Paclitaxel + Sinva, Nano-paclitaxel e Nano-paclitaxel + Sinva apresentaram redução na expressão imunohistoquímica de ICAM, MCP-1 e MMP-9 sendo que o grupo Nano-paclitaxel + Sinva apresentou a menor porcentagem de área marcada positivamente para a MMP-9. A terapia combinada com Nano-paclitaxel + Sinva é menos tóxica e mais efetiva na inibição do crescimento tumoral do que a mesma terapia com a formulação comercial do paclitaxel. / In previous studies we have proposed a novel approach for cancer treatment consisting of the use of a lipid nanoemulsion as a vehicle to direct chemotherapeutic agents to neoplastic cells. Reduction of chemotherapy toxicity promoted by specific targeting of antineoplastic agents to tumor cells led us to test the application of the lipidic nanoparticle system in combined treatment with paclitaxel and simvastatin, a cholesterol-lowering drug that can be used as coadjuvant in cancer treatment. On days 11, 14 and 19 after B16F10 melanoma cells inoculation, C57BL/6J mice were intraperitoneally injected with paclitaxel oleate associated to the lipidic nanoemulsion 17.5 &#181;mol/kg (Nano-paclitaxel), commercial formulation of paclitaxel 17.5 &#181;mol/kg, lipidic nanoemulsion (Nanoemulsion) or saline solution (Control). Simvastatin 50 mg/kg/day was administered by gavage from days 11 to 19 after tumor inoculation in one group of animals treated with Nano-paclitaxel (Nano-paclitaxel + Simva), in the group treated with commercial formulation of paclitaxel (Paclitaxel + Simva) and as monotherapy (Simva). Evaluation of possible toxic effects of the treatments was accessed in healthy Balb-c mice. Combined therapy with Nano-paclitaxel + Simva showed negligible toxicity as compared with the combination of Paclitaxel + Simva which resulted in animal weight loss and myelosuppression. In tumor-bearing animals, treatment with Nano-paclitaxel + Simva resulted in a remarkable tumor growth inhibition rate of 95%, compared to a 44% inhibition rate promoted by treatment with Paclitaxel + Simva. Moreover, only 37% of melanoma bearing animals treated with Nano-paclitaxel + Simva developed metastasis, in contrast to 90% of those treated with Paclitaxel + Simva. Survival rates were also higher in mice treated with Nano-paclitaxel + Simva in comparison to Paclitaxel + Simva treated animals. Analysis of tumor samples by flow cytometry showed that only animals treated with Simva, Nano-paclitaxel or Nano-paclitaxel + Simva increased the expression of p21 in comparison to Control group. Also, tumors from animals treated with Simva or Nano-paclitaxel + Simva presented a decrease in the expression of cyclin D1 in comparison to Control group. Cell viability test with rhodamine 123 showed mitochondrial membrane depolarization with reduction of tumor viable cells in all treatment groups in comparison to Nanoemulsion and Control groups. The histological study revealed that in contrast to drugs treated groups, tumors from Nanoemulsion and Control groups presented high tumor cell density and only Nano-paclitaxel + Simva treated animals presented tumors with increased presence of collagen fibers I and III. In comparison to Control group, tumors from groups Simva, Paclitaxel + Simva, Nano-paclitaxel and Nano-paclitaxel + Simva showed a reduction in immunohistochemical expression of ICAM, MCP-1 and MMP-9 and the group Nano-paclitaxel + Simva presented the lowest percentage of area positively stained for MMP-9. Combined therapy with Nano-paclitaxel + Simva was less toxic and more effective in promoting tumor growth inhibiton than the same combined therapy with the commercial formulation of paclitaxel.