Made available in DSpace on 2015-04-14T13:29:42Z (GMT). No. of bitstreams: 1 417773.pdf: 1138982 bytes, checksum: 03423e2cddaa5a43349be69c0853e615 (MD5) Previous issue date: 2009-08-31 / Os implantes osseointegrados, em sua maioria, possuem algum tipo de condicionamento da sua superf?cie que visa melhorar a osseointegra??o. O mecanismo de diferencia??o celular in vitro de c?lulas mesenquimais em osteoblastos j? ? bastante conhecido e serve para avalia??o das propriedades de osteoindu??o e osteocondu??o de biomateriais. O presente estudo tem por objetivo avaliar a ades?o, prolifera??o e diferencia??o das c?lulas da medula ?ssea humana em superf?cies de implantes de tit?nio com e sem deposi??o discreta de fosfato de c?lcio. As c?lulas foram obtidas a partir da medula ?ssea de um doador humano. Foram selecionados 12 discos de tit?nio do tipo Bonelike? (Biomet 3I, Brasil) com superf?cie tratada por duplo ataque ?cido; Osseotite (Biomet 3I, USA) com superf?cie tratada por duplo ataque ?cido e Nanotite (Biomet 3I, USA). Ap?s 14 e 21 dias de cultura foi realizado PCR em tempo real para avalia??o da diferencia??o celular e microscopia eletr?nica de varredura para avalia??o da prolifera??o e ades?o celular aos discos de tit?nio. Os resultados indicaram que a rugosidade da superf?cie dos discos de tit?nio possibilita a ades?o, diferencia??o e prolifera??o celular, que a s?ntese de ALP ? maior na superf?cie Bonelike e que as part?culas de fosfato de c?lcio demonstraram maior grau de s?ntese de BGLAP e prolifera??o celular.

Made available in DSpace on 2015-04-14T13:30:16Z (GMT). No. of bitstreams: 1 443201.pdf: 4831267 bytes, checksum: 8dd21e93476eb996bc1ebeb289330d2b (MD5) Previous issue date: 2012-08-31 / Osteoarthritis is a slowly progressive degenerative disease affecting several joints of the human body, including the TMJ. Tissue engineering has advanced to reduce osteochondral defects and to regenerate the TMJ. Nineteen rabbits were used in the present study. Eighteen of them had the articular discs of the TMJ removed in order to induce osteoarthritis. The animals were divided into three groups of six rabbits: group A - five rabbits treated with injections of rhGH (0.5 IU/kg) in the right joint and NaCl (0.9%) in the left joint in 14 days; group B - five rabbits received injections of rhGH (0.5 IU/kg) in the right joint and NaCl (0.9%) in the left joint in 14 and 21 days; and group C - five rabbits underwent injections of rhGH (0.5 IU/kg) in the right joint and NaCl (0.9%) in the left joint in 14, 21, and 28 days. The sixth rabbit of each group was the control and did not receive injections. The 19th rabbit was used as a normal TMJ control and did not undergo surgery. The animals were evaluated using cone beam computed tomography and histological examination. CT showed that the joints treated with three injections of 0.9% NaCl and the control group had higher rates of osteoarthritis (p < 0.05). Histological analysis revealed that the joints treated with rhGH had higher tissue cellularity and thickness in group A, whereas the joints treated with rhGH and NaCl (0.9%) had high tissue cellularity and thickness in group B than in the control group. There was no statistical difference in terms of degree of severity of osteoarthritis. / A osteoartrite ? uma doen?a lentamente progressiva e degenerativa que atinge v?rias articula??es do corpo humano, incluindo a ATM. A engenharia tecidual tem avan?ado no sentido de reduzir os defeitos osteocondrais e regenerar essa articula??o. Foram utilizados no estudo 19 coelhos, dos quais 18 tiveram os discos articulares da ATM removidos, com o intuito de induzir osteoartrite. Os animais foram divididos em 3 grupos com 6 cobaias: grupo A, onde 5 coelhos realizaram 1 infiltra??o na articula??o direita com rhGH (0,5UI/kg) e na esquerda com NaCl (0,9%) em 14 dias; grupo B, onde 5 coelhos realizaram 1 infiltra??o na articula??o direita com rhGH (0,5UI/kg) e na esquerda com NaCl (0,9%) em 14 e 21 dias; grupo C, onde 5 coelhos realizaram 1 infiltra??o na articula??o direita com rhGH (0,5UI/kg) e na esquerda com NaCl (0,9%) em 14, 21 e 28 dias. O sexto coelho de cada grupo n?o recebeu infiltra??es e serviu como controle. O 19? coelho n?o foi operado e serviu como controle de ATM normal. Os animais foram avaliados por tomografia computadorizada cone beam e histologicamente. Os resultados demonstraram que, tomograficamente, as articula??es tratadas com 3 infiltra??es de NaCl 0,9% e o grupo controle obtiveram maiores ?ndices de osteoartrite (p<0,05). Na an?lise histol?gica, as articula??es tratadas com rhGH apresentaram maior celularidade e espessura tecidual no grupo A, no grupo B, as articula??es infiltradas com rhGH e NaCl (0,9%) apresentaram maior celularidade e espessura que no grupo controle. Quanto ao grau de severidade da osteoartrite, n?o houve diferen?a estat?stica.

Made available in DSpace on 2015-04-14T13:30:23Z (GMT). No. of bitstreams: 1 448352.pdf: 2234936 bytes, checksum: 8f2dcd05e3619f61d684fbf373e529c4 (MD5) Previous issue date: 2013-03-15 / Objective: To incorporate recombinant human growth hormone in a biodegradable polymer (PLGA) Material and Methods: It was used a blend of two solvents, methanol and dichloromethane in a ratio by weight of 1.5: 5.0 for dissolving the PLGA. Another solution was made with rhGH, zinc acetate and deionized water. The two mixtures were then mixed together under mechanical stirring and poured into silicone molds circular of 01cm in diameter and around 02mm of espessur. This mixture was left in the evaporation chamber of solvent for 48 hours. The matrices were then degraded in vitro in PBS pH 7.4, thermostatted bath. The samples were removed from the bath in the range of 01, 02, 03, 04, 07, 10, 14 days. Was measured weight loss, pH and concentration of hormone released versus time. Results: The concentration of hormone released versus time was increased until the third day. On the fourth day had a fall and on the seventh day there have been increased hormone released by the tenth day, the fourteenth day was falling again. The pH had a sharp drop from 7.4 to 3.2 on the first day and keeping a small drop until the fourteenth day. The mass loss was a gradual loss in relation to time as was to be expected. Conclusion: The PLGA is a good biomaterial for making this type of device. You can incorporate the rhGH this array to get a possible material that may serve as a bone graft. / Objetivo: Incorporar o horm?nio de crescimento recombinante humano em um pol?mero biodegrad?vel o poli ?cido l?ctico glic?lico ( PLGA ) para utiliza??o na ?rea de cirurgia e traumatologia bucomaxilofacial. Materiais e M?todos: Foi utilizada mistura de dois solventes, metanol e o diclorometano numa propor??o em massa de 1,5 : 5,0 para dissolver o PLGA. Foi feita outra solu??o com o rhGH (horm?nio de crescimento humano recombinante), acetato de zinco e ?gua deionizada. As duas misturas foram ent?o misturadas sob agita??o mec?nica e vertidas em moldes de silicone circular de 01cm de di?metro e aproximadamente 02mm de espessura. Essa mistura foi deixada na c?mara de evapora??o de solvente por 48 horas. As matrizes, ent?o, foram degradadas in vitro em PBS (solu??o tamp?o fosfato salino) com pH 7.4, em banho termostatizado. As amostras foram retiradas do banho no intervalo de 01, 02, 03, 04, 07, 10, 14 dias. Foi aferida a perda de massa, varia??o do pH e concentra??o do horm?nio liberado em fun??o do tempo. Resultados: A concentra??o do horm?nio liberado em fun??o do tempo foi aumentando ate o terceiro dia. No quarto dia, houve uma queda e, no s?timo, ocorreu um aumento do horm?nio liberado, estendendo-se at? o d?cimo dia, no d?cimo quarto dia houve queda novamente. O pH teve uma queda brusca de 7.4 para 3.2 no primeiro dia e mantendo uma pequena queda at? o d?cimo quarto dia. A perda de massa foi gradual, em rela??o ao tempo, como j? era esperado. Conclus?o: O PLGA ? um bom biomaterial para esses fins. Revelou-se poss?vel incorporar o rhGH nessa matriz, de modo a, ent?o, desenvolver-se um poss?vel material que sirva como enxerto em tecido ?sseo.

Made available in DSpace on 2015-04-14T13:30:36Z (GMT). No. of bitstreams: 1 459060.pdf: 1405009 bytes, checksum: 550db90a424df77982f137b221a18c73 (MD5) Previous issue date: 2014-02-24 / The PLGA is a bioabsorbable polymer derived from lactic and glycolic acids which has been used as drug release system . One of the drugs with the potential to use this type of vehicle is the recombinant human growth hormone (rhGH), because it has advantages such as speed up the bone integration process , bone maturation and remodeling around implants, in addition to stimulating osteogenesis. Objective: This study aims to evaluate the matrix degradation of PLGA and rhGH. Materials and Methods: 75:25 (Group I) and 50:50 (Group II): Two ratios of PLGA were used. The matrices were prepared by solvent evaporation technique as it follows: firstly, the PLGA was dissolved in dichloromethane and methanol and then it was mixed with a composed mixture of recombinant human growth hormone, zinc acetate, solution and deionized water. This mixture was poured into silicone circular shape moulds approximately 10 mm diameter which were placed in a solvent evaporation chamber at room temperature, where they were dried by nitrogen gas force action. The control samples were made just dissolving PLGA and pouring it into the silicone moulds. After the drying period, all the samples were weighed on a precision scale. Then, they were immersed in buffer solution and the hydrolytic degradation experiment was investigated and the samples remained for a predetermined period of time. After this process was finished, the solid sample portion was dried and weighed again. The supernatant went through pH analysis and later, by UV-visible absortion spectrophotometry analysis. Results:It was possible to calculate the concentration of rhGH released in the middle through the straight line obtained in a calibration curve.We observed that, from the first to the last day the released rhGH concentration in the medium was higher in Group II. The loss of mass percentage increased over the time in both groups. But this loss of mass was higher in group I compared to Group II. The pH showed a little variation over the time. The average was between 7.5 and 7.9. Conclusion:The matrices which were prepared with PLGA 50:50 showed the best results in relation to the ones prepared with PLGA 75:75.These are some advantages: easy handling, more uniform pores, less bubbles and the growth hormone was released slowly and gradually. / O PLGA ? um pol?mero bioabsorv?vel derivado dos ?cidos l?ctico e glic?lico que tem sido usado como sistema de libera??o de drogas. Uma das drogas com potencial de utiliza??o nesse tipo de ve?culo ? o horm?nio do crescimento humano recombinante (rhGH), pois apresenta vantagens como, por exemplo, acelerar o processo de osteointegra??o, remodela??o ?ssea e matura??o ao redor de implantes, al?m de estimular a osteog?nese. Objetivo: Este trabalho tem por objetivo avaliar a degrada??o de matrizes de PLGA com rhGH. Materiais e M?todos: Foram utilizadas duas propor??es de PLGA: 75:25 (Grupo I) e 50:50 (Grupo II). As matrizes foram confeccionadas por meio da t?cnica de evapora??o de solventes da seguinte forma: primeiramente o PLGA foi dissolvido com diclorometano e metanol e, posteriormente, foi misturado ? uma solu??o composta por horm?nio do crescimento humano recombinante, acetato de zinco e ?gua deionizada. A mistura dessas subst?ncias foi vertida em moldes de silicone de formato circular, com aproximadamente 10 mm de di?metro, os quais foram acondicionados em uma c?mara de evapora??o de solvente, ? temperatura ambiente, onde as matrizes foram secas por meio do arraste for?ado pela a??o de g?s nitrog?nio. As amostras controle, entretanto, foram confeccionadas apenas dissolvendo o PLGA e vertendo-o nos moldes de silicone. Ap?s o per?odo de secagem todas as amostras foram pesadas em uma balan?a de precis?o. Na sequ?ncia, as matrizes foram imersas em solu??o tamp?o e realizou-se o ensaio de degrada??o hidrol?tica, no qual as amostras permaneceram por um per?odo de tempo pr?-determinado. Terminado esse processo, a parte s?lida da amostra foi seca e, novamente, pesada. O sobrenadante, ent?o, passou pela an?lise de pH e pela an?lise de espectrofotometria de absor??o UV-vis?vel. Resultados: Atrav?s da equa??o da reta obtida em uma curva de calibra??o, foi poss?vel calcular a concentra??o do rhGH liberado no meio. Com isso, observou-se que, do primeiro at? o ?ltimo dia a concentra??o de rhGH liberado no meio foi maior no Grupo II. O percentual de perda de massa foi crescente ao longo tempo, em ambos os grupos. Por?m essa perda de massa foi maior no Grupo I, em rela??o ao Grupo II. O pH apresentou pouca varia??o ao longo do tempo. A m?dia ficou entre 7,5 e 7,9. Conclus?o: As matrizes preparadas com PLGA na propor??o 50:50 apresentaram melhores resultados em rela??o ?s matrizes preparadas com PLGA 75:25. Dentre as vantagens, ressaltam-se: maior facilidade de manipula??o, poros mais uniformes, menos bolhas de ar e libera??o do horm?nio do crescimento de forma mais lenta e gradual.

Made available in DSpace on 2015-04-14T13:34:59Z (GMT). No. of bitstreams: 1 424905.pdf: 1635393 bytes, checksum: 130e114aa7e9842c1d462f5f400791c9 (MD5) Previous issue date: 2010-03-31 / Introdu??o: A cont?nua exposi??o da membrana peritoneal ?s solu??es de di?lise peritoneal convencionais, consideradas n?o fisiol?gicas, ? um dos fatores de risco para o desenvolvimento de altera??es morfol?gicas e funcionais do perit?nio. Objetivo: Comparar a viabilidade celular in vitro de fibroblastos de camundongos NIH/3T3 expostos a diferentes solu??es de di?lise peritoneal. Materiais e M?todos: Estudo experimental; onde foram realizadas culturas de fibroblastos empregando meios de cultura contendo diferentes solu??es de di?lise (padr?o e pH-neutro) nas 3 concentra??es de glicose dispon?veis. A viabilidade celular foi avaliada pelo m?todo do sal de tetraz?lio. Resultados: A viabilidade celular foi significativamente superior na solu??o com pH neutro em compara??o a solu??o controle, nas tr?s concentra??es de glicose (Densidade ?ptica-m?dia ? dp: 1.5%controle 0,295?0,047 vs 1,5%pH neutro 0,372?0,042 P<0,001; 2,3%controle 0,270?0,036 vs 2,3% pH neutro 0,337?0,051 P<0,001; 4,25%controle 0,284?0,037 vs 4,25%pH neutro 0,332 ? 0,032 P<0,001). N?o ocorreu diferen?a significativa na viabilidade celular entre as tr?s concentra??es de glicose quando se usou a solu??o de di?lise peritoneal padr?o (ANOVA P=0,218), embora a viabilidade celular foi maior ap?s a exposi??o ? solu??o com pH neutro na concentra??o de glicose de 1,5% em compara??o com 2,3 e 4,25% (ANOVA P=0,008: Bonferroni 1,5% vs 2,3% P=0,033, 1,5% vs 4,25% P=0,014, 2,3% vs 4,25% P=1,00). Conclus?o: A viabilidade celular foi maior nos fibroblastos expostos a solu??o de di?lise peritoneal com pH neutro, especialmente nas menores concentra??es de glicose. ? poss?vel que o pH mais fisiol?gico e a menor quantidade de produtos de degrada??o da glicose possam ser respons?veis pelos resultados.

Made available in DSpace on 2015-04-14T13:35:07Z (GMT). No. of bitstreams: 1 429852.pdf: 2540370 bytes, checksum: 378be904793c28ab99288056e50d378f (MD5) Previous issue date: 2011-01-03 / Objetivo: Os autores apresentam o primeiro estudo com o uso de Fluoresce?na S?dica (FS) para contrastar tumores da base do cr?nio e realizam uma an?lise quantitativa digital do contraste tumoral. O estudo tem por objetivo observar o grau de contraste tumoral pela FS. M?todos: Foi realizado um estudo experimental prospectivo com controle intragrupo, incluindo seis pacientes com les?es da base do cr?nio. Fotografias digitais foram realizadas antes e ap?s a administra??o sist?mica de FS, utilizando a mesma fonte de ilumina??o do campo microcir?rgico. As fotografias pr? e p?s inje??o de FS foram analisadas por um software, o qual calculou o comprimento de onda da FS nas respectivas imagens. Resultados: O grupo de tumores foi constitu?do por: 1 schwanoma vestibular, 3 meningeomas, 1 craniofaringeoma e 1 adenoma de hip?fise. O contraste dos tumores pela FS foi fortemente positivo. A an?lise digital das fotografias, considerando os comprimentos de onda pr? e p?s inje??o de FS, apresentou p=0,028 (Teste T de Wilcoxon). Conclus?es: O contraste dos tumores pela FS foi consistente. Os resultados introdut?rios sugerem a possibilidade de uso da FS como uma ferramenta adjuvante para a cirurgia da base de cr?nio. Estudos complementares s?o necess?rios para definir aplica??o cl?nica da FS em tumores da base do cr?nio.

Ceramic materials are natural or synthetic, inorganic, non-metallic materials incorporating ionic and covalent bonding. Most ceramics in use are polycrystalline materials where grains are connected by a network of solid-solid interfaces called grain boundaries. The structure of the grain boundaries and their arrangement play a key role in determining materials properties. Developing a fundamental understanding of the formation, structure, migration and methods of control grain boundaries have drawn the interest of scientists for over a century.<br> While grain boundaries were initially treated as isotropic, advances in materials science has expanded to include energetically anisotropic boundaries. The orientation and structure of a grain boundary, determined by this anisotropy, controls the mobility of a grain boundary. The mobility is the controlling factor during grain growth impacting the microstructural evolution of a material.<br> This thesis covers fundamental research to model how a materials’ equilibrium crystal shape can be used as a grain growth control mechanism. First an overview of ceramic processing and microstructural development is presented with a focus on the role of grain boundaries in determining the properties of a material. The role of anisotropy and related recent work is highlighted setting the foundation for the link between the equilibrium crystal shape and grain growth. A discussion on the selection of the NiO-MgO system for all experimental work is included.<br> A novel production and processing route for NiO-MgO was developed. Mechanical alloying and milling resulted in significant impurity contamination therefore a chemical production route was used. A modified amorphous citrate process was developed where metal salts containing Ni and Mg were mixed with a polyfunctional organic acid. Rapid dehydration and calcination at 500°C resulted in chemically homogeneous powders. The amorphous citrate production route produced powder with crystallites ranging from 244-393 nm and agglomerates ranging from 20-300 μm with plate-like morphology.<br> NiO-MgO powders produced via the amorphous citrate method were sintered using various techniques. Conventional sintering was unable to produce fully dense samples peaking with relative densities from 95-96%. The introduction of pressure through spark plasma sintering and hot pressing improved the relative sample density to 97-100%. It was discovered that exposure to the vacuum required for spark plasma sintering and hot pressing resulted in the reduction of NiO. Spark plasma sintering created oxygen depleted regions and hot pressing further reduced NiO to pure nickel metal which precipitated out at the grain boundaries.<br> Due to the poor sintering behavior of NiO-MgO grain growth experiments were carried out on the large agglomerates formed during the amorphous citrate process. Agglomerates with more than 50 grains with a thickness of at least 1 μm were selected. Grain growth was measured across five compositions with Ni:Mg ratios of 100:0, 75:25, 50:50, 25:75, 0:100. The average grain size and growth rate increased with increasing nickel content with a significant jump between 50% and 75%. Increasing nickel content was also observed to correspond with a higher number of grains exhibiting surface faceting.<br> The NiO-MgO equilibrium crystal shape as a function of composition was measured previously. To make the equilibrium crystal shape a more viable control for grain growth a quantitative microstructural characterization technique was developed to measure a materials equilibrium crystal shape. Topographic surface information (surface facets measured by atomic force microscopy, AFM) and grain crystallographic orientation (measured by electron back-scattered diffraction, EBSD) were combined to produce the crystallographic topography of a sample surface. Surface crystallographic topography was used to identify the faceting behavior of grains with a range of orientations. Using the combined data, facet stability maps (n diagrams) for NiO-MgO were developed.<br> Controlling grain growth via the equilibrium crystal shape offers the potential to produce microstructures with a high frequency of desirable grain boundaries (grain boundary engineering) and therefore properties. The combination of using AFM and EBSD to create crystallographic topographical surface data and n-diagrams has been demonstrated. N-diagrams for most materials do not exist, but the technique used here can be applied to a wide range of materials and will expand the ability to control microstructures of ceramic materials.<br><br>

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-05-17T20:18:03Z No. of bitstreams: 1 TES_ALEXANDRE_DA_SILVEIRA_GERZSON_COMPLETO.pdf: 8833517 bytes, checksum: b4672493ffabfc3e5c284282aa067e14 (MD5) / Made available in DSpace on 2016-05-17T20:18:03Z (GMT). No. of bitstreams: 1 TES_ALEXANDRE_DA_SILVEIRA_GERZSON_COMPLETO.pdf: 8833517 bytes, checksum: b4672493ffabfc3e5c284282aa067e14 (MD5) Previous issue date: 2016-03-23 / Biomaterials, as an alternative to autogenous bone and other biological tissues, have been widely used in oral and maxillofacial surgery. In this context, a biomaterial that functions as a scaffold (osteoconductor), combined with a growth factor (osteoinductor), would be of great interest for clinical application. Biodegradable polymers used for slow drug release have been investigated, demonstrating good results and interesting potential. Growth hormone (rhGH) may be released by incorporating it into these polymers. This study aimed to evaluate cell adhesion and proliferation of a polymeric biomaterial for slow release of rhGH. PLGA and PLGA/PCL (at a 70/30 ratio of PLGA to PCL) matrices were prepared by the solvent evaporation method, combined or not with GH. The biomaterials were tested for toxicity and cell viability using an MTT assay with NIH3T3 mouse cells (ATCC). Cell toxicity was assessed at 24, 48, 72 hours, and 7 days of biomaterial exposure to culture medium. After were tested?for cell adhesion and proliferation by culture in mesenchymal stem cells derived from Wistar rat bone marrow, DAPI staining, and subsequent cell counting, in addition to scanning electron microscopy. Cell adhesion and proliferation was assessed at 24 and 72 hours of biomaterial exposure to culture medium. All polymers had high cell viability rates. However, from 48 hours onwards, the groups with rhGH-polymer combinations had better results than the polymer groups without association with GH when compared to the control group. At 7 days of culture, only the pure PLGA matrix showed a significant difference from the control group. These results may suggest a preference of cells for the presence of rhGH in the biomaterial in culture medium? especially in the PLGA matrix. GH appeared to contribute to the increase in cell viability observed at some assessment time points, especially when combined with PLGA as compared to pure PLGA. All tested polymers exhibited cell adhesion and proliferation. However, PLGA-based biomaterials, especially when combined with rhGH, showed greater cell proliferation when the difference in growth from 24 to 72 hours was evaluated. rhGH appeared to modify the polymer surface, with increased roughness and microporosity. This feature was more evident in the PLGA+rhGH combination. Further studies are required to clarify this potential for development of new biomaterials. / Biomateriais como alternativas ao osso aut?geno e outros tecidos biol?gicos, s?o muito utilizados no tratamento de pacientes na rotina cir?rgica da regi?o maxilofacial. Neste contexto, um biomaterial com caracter?sticas de arcabou?o (osteocondutor), e associado ? um fator de crescimento (osteoindutor), seria de grande interesse para pesquisa e aplica??o cl?nica. Pol?meros biodegrad?veis, utilizados para a libera??o lenta de medicamentos, vem sendo estudados, demonstrando bons resultados e interessante potencial. o rhGH pode ser liberado atrav?s da sua incorpora??o ? estes pol?meros. Desta forma, se faz necess?rio a avalia??o da biocompatibilidade e toxicidade de um biomaterial polim?rico para libera??o lenta do medicamento. Atrav?s da t?cnica de evapora??o de solvente foram preparados matrizes de PLGA e PLGA/PCL na raz?o 70/30 de PLGA e PCL, respectivamente, associados ou n?o ao rhGH. Os biomateriais foram testados relacionados ? sua toxicidade e viabilidade celular, atrav?s de um ensaio de MTT com c?lulas de camundongo NIH 3T3 ATCC. A avalia??o da toxicidade celular foi realizada nos tempos de 24 horas, 48 horas, 72 horas e 7 dias de exposi??o dos biomateriais com o meio de cultura. Ap?s, os biomateriais foram testados relacionados ? sua ades?o e prolifera??o celular, atrav?s do cultivo em c?lulas-tronco mesenquimais de rato Wistar, com ensaio de colora??o DAPI e posterior contagem celular, al?m de microscopia eletr?nica de varredura. A avalia??o da ades?o e prolifera??o celular foi realizada nos tempos de 24 e 72 horas de exposi??o dos biomateriais com o meio de cultura. Todos os pol?meros testados apresentaram altas taxas de viabilidade celular, por?m, os grupos associados ao rhGH parecem demonstrar melhores resultados do que os grupos de pol?meros sem associa??o ao horm?nio quando comparados ao grupo controle em alguns per?odos do experimento. O que pode sugerir uma prefer?ncias das c?lulas ? presen?a do rhGH no biomaterial presente no meio de cultura, principalmente na matriz de PLGA. Os pol?meros testados, apresentaram ades?o e prolifera??o celular, por?m, os biomateriais ? base de PLGA, principalmente associados ao rhGH pareceram demonstrar maior prolifera??o celular quando avaliada a diferen?a do crescimento de 24 para 72horas. O GH modificou a superf?cie do pol?mero, aumentando a rugosidade e microporosidade. Aspecto visualizado principalmente quando incorporado ao PLGA. Mais estudos s?o necess?rios para verificar alternativas de novos biomateriais para libera??o lenta de f?rmacos.

Made available in DSpace on 2014-12-17T15:41:57Z (GMT). No. of bitstreams: 1 VitorRMM_DISSERT.pdf: 2544703 bytes, checksum: 4453e8b3e10e994e669daf77efdaa72b (MD5) Previous issue date: 2012-08-04 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Perovskites oxides win importance by its properties and commercials applications, they have a high thermal stability, have conductive properties, electrical, catalytic, electro catalytic, optical and magnetic, and are thermally stable. Because of these properties, are being widely studied as carriers of oxygen in the process of power generation with CO2 capture. In this work, the base carrier system La1-xMexNiO3 (Me = Ca and Sr) were synthesized by the method via the combustion reaction assisted by microwave. were synthesized from the combustion reaction method by microwave process. This method control the synthesi`s conditions to obtain materials with specific characteristics. The carriers calcined at 800 ? C/2h were analyzed by thermal analysis (TG-DTA), to verify its thermal stability, X-ray diffraction (XRD) to verify the phase formation, with subsequent refinement by the Rietveld method, to quantify the percentage of phases formed, the surface area by BET method was determined, scanning electron microscopy (SEM) was obtained to evaluate the material morphology and temperature programmed reduction (TPR) was done to observe the metallic phase of the nickel. After all proposed characterization and analysis of their results can be inferred to these oxides, key features so that they can be applied as carriers for combustion reactions in chemical cycles. The final products showed perovskite-type structures K2NiF4 (main) and ABO3. / ?xidos com estrutura tipo perovsquita destacam-se por suas diversas propriedades e aplica??es comerciais, pois possuem alta estabilidade t?rmica, apresentam propriedades condutoras, el?tricas, catal?ticas, eletrocatal?ticas, ?pticas e magn?ticas, al?m de serem termicamente est?veis. Devido a estas propriedades, est?o sendo amplamente estudados como carreadores de oxig?nio em processos de gera??o de energia com captura de CO2. Neste trabalho, carreadores a base do sistema La1-xMexNiO3 ( Me = Ca e Sr) foram sintetizados a partir do m?todo via rea??o de combust?o assistida por microondas. Este m?todo controla as condi??es de s?ntese para obten??o de materiais com caracter?sticas espec?ficas. Os carreadores calcinados a 800?C/2h foram analisados atrav?s de an?lise t?rmica (TG-DTA), para verifica??o de sua estabilidade t?rmica; difra??o de raios-X (DRX), para verifica??o das fases formadas, com posterior refinamento atrav?s do m?todo de Rietveld, para quantificar o percentual das fases formadas; ?rea superficial pelo m?todo BET; microscopia eletr?nica de varredura (MEV) e redu??o ? temperatura programada (TPR). Ap?s toda caracteriza??o proposta e an?lise dos seus resultados pode-se inferir a esses ?xidos, caracter?sticas fundamentais para que os mesmos possam ser aplicados como carreadores em rea??es de combust?o por ciclos qu?micos. Os carreadores de oxig?nio obtidos possuem estruturas perovsquitas do tipo K2NiF4 (principal) e ABO3.

Made available in DSpace on 2016-04-28T14:56:19Z (GMT). No. of bitstreams: 1 2009 - Ludmila de Carvalho Sampaio.pdf: 1705521 bytes, checksum: a3e7341ce10bb882edcbb905becd1778 (MD5) Previous issue date: 2009-06-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The Restinga is one type of sand coastal ecosystems that are suffering with high anthropic impact and is important the consideration of any action related to the recovery and conservation of the last remaining areas. For that, is necessary to study the grown and the best conditions for seedling production of species that are native from these ecosystems. In this context, the present work had the objectives: 1- study the response of Senna appendiculata and Senna bicapsularis to different sources and amount of nitrogen. 2- study the response of S. appendiculata, Senna bicapsularis and Machaerium lanceolatum to lime and to a changes in the soil pH. The experiments were conduct under greenhouse conditions in pots filled with sand soil with low fertility. For the experiment with different sources and amount of nitrogen, seven treatments were applied: control (without nitrogen), NO3? (10 mg N/ plant), NO3? (20 mg N/plant), NH4+ (10 mg N/plant), NH4+ (20 mg N/plant), NO3NH4 (10mg N/plant) e NO3NH4 (20 mg N/plant). For the experiments with lime and soil pH, four treatments were applied: 0, 2. 4 and 6 t/ha of lime. For each experiment, the following measurement were made: shot and root dry weight, root length, plant height, soil pH, root/shoot ratio, collar diameter and relative growth rate (RGR was estimated only for S .pendula). The results suggest tendency for indicate that the preferential source of nitrogen for S. appendiculata was NH4+. However for S. pendula with the obtained results is not possible to describe the preferential source of nitrogen, although the grown was affected by the nitrogen applied. None of studied plants had the growth limited by acid soil conditions. Senna appendiculata showed preference for growing at low soil pH and the lime was not necessary for the promotion of plant grown. In this conditions if lime is applied can cause a decrease in plant grown. Lime applied showed no effect on the growth of M. lanceolatum. / Devido ao elevado estado de degrada??o dos ecossistemas de restinga ? de extrema import?ncia considerar a??es para a conserva??o e recupera??o dos poucos remanescentes ainda existentes. Para isso faz-se necess?ria a realiza??o de estudos relacionados ao crescimento das esp?cies encontradas nestas ?reas, visando melhores condi??es para a produ??o de mudas. Dentro desta proposta, o presente trabalho teve como objetivos: 1- avaliar o crescimento de Senna appendiculata e Senna bicapsularis, utilizando diferentes fontes e doses de nitrog?nio mineral; e 2- caracterizar a resposta de Senna appendiculata, Senna bicapsularis e Machaerium lanceolatum ? calagem e a mudan?as do pH do solo. Os experimentos foram conduzidos em condi??es de casa de vegeta??o, em vasos contendo como substrato, solo arenoso de baixa fertilidade. Para o experimento de efeito de diferentes doses e fontes de nitrog?nio foram utilizados sete tratamentos: testemunha (sem nitrog?nio), NO3? (10 mg N/planta), NO3? (20 mg N/planta), NH4+ (10 mg N/planta), NH4+ (20 mg N/planta), NO3NH4 (10mg N/planta) e NO3NH4 (20 mg N/planta). No experimento de resposta ? calagem e mudan?a do pH do solo foram utilizados quatro tratamentos: 0, 2, 4 e 6 t de calc?rio/ha. Os par?metros avaliados foram: altura da planta, comprimento da raiz, ac?mulo de mat?ria seca da raiz e da parte a?rea, di?metro do coleto, pH do solo, rela??o raiz/parte a?rea, incremento m?dio em altura (IMA) e taxa de crescimento relativo, este ?ltimo apenas para a esp?cie S. pendula. Os resultados obtidos apresentam uma tend?ncia a indicar que a fonte preferencial de nitrog?nio para a esp?cie S. appendiculata seria o am?nio. O crescimento da esp?cie Senna pendula foi influenciado pela aplica??o de nitrog?nio, no entanto n?o foi poss?vel determinar a fonte de nitrog?nio preferencial. Nenhuma das esp?cies estudadas teve seu crescimento limitado em condi??es de solo ?cido. A esp?cie S. appendiculata demonstrou prefer?ncia por solos ?cidos e a calagem n?o seria necess?ria para a produ??o de mudas desta esp?cie, podendo influenciar negativamente o crescimento da mesma. A calagem n?o influenciou o crescimento de M. lanceolatum.