Orientadores: Mary Ann Foglio, João Ernesto de Carvalho, Rodney Alexandre Ferreira, Rodrigues / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-15T16:14:15Z (GMT). No. of bitstreams: 1 Servat-Medina_Leila_M.pdf: 3025088 bytes, checksum: aa495f96cd7e554ebadfda7401c5b4bb (MD5) Previous issue date: 2010 / Resumo: As plantas medicinais têm sido fonte de agentes medicinais há milhares de anos para o tratamento de um amplo espectro de doenças. Entre as alternativas que podem ser utilizadas para preservar as características do material vegetal, destaca-se a encapsulação em micropartículas. Estudos prévios com espécie Pterodon pubescens Benth. (sucupira) avaliaram a eficácia (ação antiinflamatória e antinociceptiva) e a segurança (eventuais efeitos toxicológicos) dos extratos, frações ativas e compostos isolados de P. pubescens. No presente trabalho, avaliou-se o benefício do processo de microencapsulação por spray drying para preservação das características químicas, aliado a ações biológicas in vitro e in vivo dos extratos e compostos isolados. Extratos brutos produzidos com sementes provenientes de Minas Gerais (EBMG), Bahia (EBBA), Mato Grosso (EBMT) ou São Paulo (EBSP) apresentaram perfil químico distinto, demonstrando a variabilidade química da espécie de diferentes procedências. A partir dos extratos EBMG e EBSP foram isolados os vouacapanos C1 e C2, ambos com atividade antinociceptiva, sendo que a atividade de C1 esteve mais relacionada a componente de dor neurogênica. C1 e os extratos EBBA, EBSP e EBMT foram microencapsulados por spray drying e, juntamente com as amostras livres, armazenados em câmara climática com umidade e temperatura controladas para o estudo de estabilidade. Os resultados dos ensaios de atividade anticâncer in vitro em células tumorais humanas e atividade antinociceptiva em modelos com camundongos, demonstraram que a técnica de microencapsulação por spray drying preservou a ação, tanto do composto isolado quanto dos extratos demonstrando ser uma alternativa útil para prolongar o tempo de estocagem, principalmente do extrato bruto.As vantagens apresentadas pelo processo de microencapsulação dos produtos obtidos a partir de P. pubescens, motivam a continuidade dos estudos de padronização com esta espécie, para viabilizar um produto que atenda a parâmetros de reprodutibilidade, eficácia e segurança. / Abstract: Over the years natural products, especially plants, have demonstrated to play a dominant role for drug discovery to treat human diseases. Micro encapsulation is an important approach to preserve natural products characteristics. Previous studies with Pterodon pubescens Benth., (sucupira) evaluated the efficacy (anti-inflammatory and antinociceptive) and safety (possible toxicological effects) of the extracts, active fractions and compounds isolated from P. pubescens. In the present study we evaluated the benefit of the microencapsulation process by spray drying to preserve the chemical characteristic monitored by in vitro and in vivo biological activities. Crude extracts obtained from Minas Gerais (EBMG), Bahia (EBBA), Mato Grosso (EBMT) or São Paulo (EBSP) seeds showed different quimical profiles. Vouacapans C1 and C2, isolated to EBMG and EBSP crude extracts, demonstrated antinociceptive activity, C1 activity related to neurogenic pain. The crude extracts EBBA, EBSP, EBMT and compound C1 were microencapsulated by spray drying and, along with control samples, stored in a climatic chamber with controlled humidity and temperature for the accelerated stability studies. The test results of in vitro anticancer activity in human tumor cells and antinociceptive activity in mice models, showed that the microencapsulation technique by spray drying preserve both the isolated compound and extracts. This technique is a useful alternative to extend storage time, especially of the crude extract. The advantages presented by P. pubescens microencapsulated products prompt to continue studies with this species, for the production of a product that meets reproductively, efficacy and safety parameters. / Mestrado / Farmacologia, Anestesiologia e Terapeutica / Mestre em Odontologia

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Licopeno, um pigmento natural considerado o mais potente antioxidante dentre os carotenoides, é oque tem maior incidência no soro humano. Seu consumo regular está relacionado principalmente com a prevenção do câncer de próstata. Porém, estudos também demonstram sua relação com a prevenção de câncer de pâncreas e bexiga, doenças cardiovasculares como a aterosclerose e doenças neurodegenerativas. Todavia, por ser altamente insaturado o licopeno é susceptível à degradação, sendo degradado na presença de luz, oxigênio e se exposto a altas temperaturas. A microencapsulação entra como uma alternativa para tentar garantir maior estabilidade a este carotenoide. A técnica de spray-chilling, por dispensar o emprego de altas temperaturas e solventes durante o processo de atomização, representa uma alternativa promissora na encapsulação do licopeno. Os objetivos deste trabalho foram encapsular uma solução oleosa de licopeno (10%) através da técnica de spray-chilling,utilizando gordura vegetal low trans como carreador, caracterizar as micropartículas obtidas e avaliar a biodisponibilidade do licopeno livre e encapsulado em ratos wistars. Foram formulados seis tratamentos, que diferiam pela concentração de solução comercial de licopeno, sendo T1 com 20%, T2 com 23,1%, T3 com 28,6%, T4 com 33,3%, T5 com 17,9% mais 10% de goma arábica e T6 com 19,2% mais 5% de carboximetilcelulose (CMC). As micropartículas obtidas destes tratamentos foram avaliadas quanto a tamanho e distribuição, morfologia por microscopia eletrônica de varredura (MEV), espectroscopia de infravermelho com transformadas de Fourier (FT-IR), difração de raios-X (DRX). A estabilidade do licopeno encapsulado foi avaliada em diferentes condições de armazenamento (sob vácuo, umidade relativa de 33%, temperatura de refrigeração e ambiente) e também foi determinada por meio de quantificações periódicas de licopeno, bem como através da análise análise da cor instrumental. A biodisponibilidade foi avaliada utilizando-se 68 animais divididos em grupos, para os quais se administrou por gavagem o licopeno livre e o encapsulado. O tamanho das micropartículas obtidas ficou em torno de 60-110 µm e a distribuição foi polidispersa, independente da concentração de licopeno. A microscopia revelou micropartículas esféricas, com superfície rugosa, com alguns poros e tamanhos variados. No FT-IR verificou-se que não houve formação de ligações distintas na solução oleosa de licopeno e nas amostras atomizadas. Nos difratogramas observou-se a presença da forma polimórfica β para o agente carreador e para as micropartículas. Na estabilidade a adição da goma arábica e o armazenamento sob temperatura de refrigeração e vácuo, foram as melhores condições para retardar a degradação do licopeno. Os resultados dos ensaios de biodisponibilidade foram inconclusivos. Desta forma, conclui-se que é possível encapsular licopeno através da técnica de spray-chilling, porém, para trabalhos futuros, seriam necessários aprimoramentos na técnica de encapsulação e/ou na formulação para conferir maior proteção ao carotenoide, bem como adequações na metodologia para determinação de sua biodisponibilidade, para obtenção de resultados conclusivos. / Lycopene, a natural pigment considered the most potent antioxidant among the carotenoids, it has the higher incidence in the human serum. Its regular consumption is mainly related with the prevention of prostate cancer. However, studies also show its relation to the prevention of pancreatic cancer and bladder cancer, cardiovascular diseases such as atherosclerosis and neurodegenerative diseases. However, by being highly unsaturated the lycopene is susceptible to degradation, being degraded in the presence of light, oxygen and if exposed to high temperatures. The microencapsulation comes like an alternative to ensuring higher stability for this carotenoid. The technique of spray-chilling represents a promising alternative to encapsulation of lycopene. The aims of this study were to encapsulate an oily solution of lycopene (10%) through of the technique of spray-chilling, using a low-trans fat as carrier, to characterize the obtained microparticles and to evaluate the bioavailability of lycopene free and encapsulated in Wistar rats. Six treatments were formulated, that differed by the content of oily solution of lycopene:T1 with 20%, T2 with 23.1%, T3 with 28.6%, T3 with 28.6%, T4 with 33.3%, T5 with 17.9% plus 10% of Arabic gum and T6 with 19.2% plus 5% of carboxymethylcellulose (CMC). The microparticles obtained from these treatments were evaluated for size and distribution, morphology by scanning electron microscopy (SEM), infrared spectroscopy with Fourier transform (FT-IR) and X-ray difraction (XRD). The stability of the lycopene encapsulated was evaluated by its periodic quantification at different storage conditions (vacuum, relative humidity of 33%, refrigeration temperature and environment temperature). Instrumental color, \"L\" and \"a\" parameters, also was measured. The bioavailability was evaluated using 68 animals, for which the free and lycopene encapsulated were administered by gavage. The size of microparticles obtained was around 60-110 µm and the distribution was polydisperse, independent of the concentration of lycopene. The microscopy revealed spherical microparticles, with rough surface, with some pores and varying sizes. In the FT-IR it was found that there was no formation of distinct bonds in oily solution of lycopeno and the atomized samples. In the diffraction patterns observed the presence of polymorphic form \"β\" for the carrier agent and microparticles. On the stability the addition of Arabic gum and the storage at refrigerator temperature under vacuum, were the best conditions to delay the degradation of lycopene. The results of bioavailability assays were inconclusive. As conclusion, it is possible to encapsulate lycopene using the technique of spray-chilling but to future works, would be required improvements in the technique of encapsulation and/or formulations to give more protection to the carotenoid, as well as adjustments in the methodology for determination of their bioavailability, in order to obtaining conclusive results.

Metal-ceramic (Cermets) materials that combine properties of both: high hardness, high wear resistance, and high working temperatures of ceramics and the ductility, toughness, and heat conductance of metals. Cold gas dynamic spraying, or simply cold spray, is a solid state thermal spray process that has been in development for the last 25 years. In the cold spray process, ductile materials are accelerated in a supersonic flow. These particles impact a substrate and adhere by plastic deformation. The continuous accumulation of these particles covers the substrate and creates a dense coating. The cold spray process is beginning to become a popular method to consolidate some select cermet materials into coatings. This technique can be advantageous when an erosion and wear resistant coating is required. During the deposition of these coatings, researchers have shown that the ceramic particles have a dramatic influence on the deposition behavior by causing an increase in deposition efficiency and coating adhesion. These effects have been presented in several experiments but have yet to be thoroughly explained. The goal of this investigation is to increase the knowledge, on a fundamental level, with regards to the deposition behavior of metal-ceramic blending and cermet powders. Ultimately, the focus is to prove the feasibility of these coatings for the requirements needed in the engineering industry. The first part of the investigation is a fundamental study on the deposition behavior of metal-ceramic blends with different compositions. Three theories that aim to explain the increase in deposition efficiency were proposed in the literature and further investigated in this study. One proposed mechanism for the increase in deposition efficiency was established by probability analysis to be too unlikely to contribute to the increment in deposition efficiency. The other two proposed mechanism, the presence of asperities caused by ceramic particles, and the oxide removal produced by the impact of ceramic particles, shown to play a major role in increasing the deposition efficiency. The effect of the ceramic particle morphology on the deposition behavior of metal-ceramic blending was studied in the second part of the investigation. This study greatly complements the previous one adding more depth to the investigation and confirming results. The increment in deposition efficiency normally seen with the addition of small amounts of angular alumina was not seen when spherical alumina was added instead. The creation of asperities during deposition was explored for the two morphologies and was determined that spherical alumina does not produce the same asperities at the surface. In addition, the coating sprayed with spherical alumina showed very little ceramic retention compared with the ones sprayed with angular alumina. These results have a direct impact on the mechanical properties of the coatings. Wear resistance for coatings sprayed with spherical alumina showed no improvement compared with pure aluminum coating due to the low ceramic content. Hardness was lower in coatings sprayed with spherical alumina for the same feedstock powder composition but was harder when the final coating composition was considered. Adhesion strength significantly increases with the addition of ceramic content in the feedstock powder; this increase was greater for coating sprayed with spherical alumina. The third part of the investigation focuses on understanding the mechanism of deposition for cermet particles with various morphologies. Six commercially available CrC-NiCr powders were studied, varying in morphology and metal/ceramic ratio. Spherical powders led to the erosion of the substrate and no coating was formed. Porous agglomerated and sintered powder lead to severely cracked coatings. For dense agglomerated and sintered powders, the outcome of powder depended on the initial metal/ceramic ratio, powders with 25%wt.NiCr led to erosion while 35%wt.NiCr powders led to a dense coating. Finally blended ceramic metal powders also lead to a successful coatings. All coatings obtained had lower ceramic content than the initial feedstock powder. Interrupted deposition tests, FEA analysis, and SEM observation were used to draw conclusions on the deposition behavior and explain the results. Finally, the last part of this investigation aims to apply the knowledge learned to an applied engineering problem. The problem that is targeted is the replacement of chrome plating for the aerospace industry. A commercially available cermet powder CrC-NiCr (65/35) was proposed as a replacement of chromium plating as well as a restoration for this coating and its alternatives (electroless nickel-plating, and WC-Co-Cr HVOF). The coatings and restoration were analyzed by SEM and tested by strip rupture rest, neutral salt spray fog, and fluid immersion testing. The adhesion strength, porosity, and hardness of the cold spray coating was also tested. The deposition and restoration of coatings were successful; a hard and dense coating was obtained with good adhesion strength. The process of restoration chromium-plating and its alternatives was also developed with a clean interface was achieved in each case. Coatings and restoration passed strip to rupture rest as well as fluid immersion test in two selected industry fluids. Neutral salt spray fog test revealed that the cold spray coating and repairs may have a path that allows the solution to penetrate the substrate and start the corrosion process. This behavior was found in a few select spots and should be further investigated. Overall, the coating proved to have potential as an alternative of chromium-plating or to restore damaged hard coatings.