Orientador: João Batista Fogagnolo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-27T20:13:02Z (GMT). No. of bitstreams: 1 RodriguezPerez_JessicaMarlena_M.pdf: 4283527 bytes, checksum: 428a287377aaab009ef368ca3005561b (MD5) Previous issue date: 2015 / Resumo: O interesse em ligas do sistema titânio-nióbio para aplicações ortopédicas se deve à excelente resistência mecânica e biocompatibilidade, sendo que o módulo de elasticidade pode ser controlado pelo teor de nióbio. Existem diversos processos que podem tornar estas ligas adequadas para uso como biomaterial e que resultam em diferentes fases com diferentes propriedades. O presente trabalho teve como objetivo modificar peças sinterizadas de ligas do sistema titânio-nióbio por refusão superficial por laser. Foram utilizadas ligas com diferentes composições químicas, variando-se o teor de nióbio de 5 a 45% em peso. Foram analisados os efeitos da variação dos parâmetros de processamento, potência e velocidade de deslocamento do feixe laser, sobre a morfologia de cordões isolados. Foram obtidas camadas contínuas de refusão por sobreposição de cordões de isolados. As amostras sinterizadas com teores de nióbio entre 5 e 20% apresentaram as fases ? e ?. A amostra com teor de nióbio de 25% e maiores apresentam regiões com fase ? completamente estabilizada e regiões com as fases ? e ? devido à heterogeneidade química na distribuição de nióbio. A amostra com teor de nióbio de 45% apresenta apenas a fase ?, porém também se observa nessa amostra a heterogeneidade na distribuição de nióbio. Constatou-se que a potência do feixe de laser é o parâmetro de maior influência na morfologia e dimensões da zona fundida dos cordões isolados. Dependendo do teor de nióbio, diferentes fases são formadas nas camadas continuas de refusão. Para teor de nióbio de 5%, obtém-se a fase martensítica ?', de estrutura hexagonal. Para teor de nióbio de 15%, obtém-se majoritariamente a fase ?' com presença da fase martensítica ortorrômbica ?''. Para teor de nióbio de 25%, obtém-se a fase ?'', com pequena fração de fase ?. Para teor de nióbio de 35 e 45%, obtém-se a fase ? em toda a zona fundida e a fase ?'' na zona termicamente afetada. Tanto os cordões isolados como as camadas refundidas das amostras com teores de 15, 25, 35 e 45% em peso de nióbio apresentaram heterogeneidade química devido à microssegregação de soluto durante a solidificação. Os valores de módulo de elasticidade medidos por nanoindentação foram decrescentes para aumentos da quantidade de nióbio, tanto nas zonas modificadas pelo laser quanto no substrato sinterizado. Os valores de nanodureza mantiveram-se constantes, dentro da variação estatística dos resultados / Abstract: The interest in alloys of the titanium-niobium system for orthopedic applications is due to their excellent mechanical resistance and biocompability, as the elastic modulus may be controlled by niobium content. There are several processes that can make those alloys adequate to be used as biomaterials and that result in different metallic phases with different properties. The objective of this study was to modify, by laser surface remelting, sintered parts of alloys from the titanium-niobium system. Alloys with different chemical compositions were used; the niobium content varied from 5 to 45wt%. The effects of the variation of processing parameters (laser beam power and scan speed) on the morphology of the isolated tracks were analyzed. Continuous remelting layers were obtained by overlapping isolated tracks. The sintered samples with niobium content between 5 and 20% exhibited both ? and ? phases. The sample with a niobium content of 25% or more had regions of completely stabilized ? phase and regions of ? and ? phases due to the chemical heterogeneity in the niobium distribution. The sample with a 45% niobium content showed only the ? phase, but heterogeneity in the niobium distribution is also seen. It was found that the laser beam power is the parameter that most influences the morphology and dimensions of the molten area of isolated tracks. Depending on the niobium content, different phases are formed in the continuous remelting layers. For a niobium content of 5%, the martensitic ?' phase of hexagonal structure is obtained. For a niobium content of 15%, the ?' phase is mostly obtained, with the presence of orthorhombic, martensitic ?'' phase. For a niobium content of 25%, the ?'' phase, with a small fraction of ? phase, is obtained. For niobium contents of 35 and 45%, ? phase throughout the molten area and ?'' phase in the heat affected zone are obtained. Both the isolated tracks and the continuous remelting layers on the samples with niobium weight contents of 15,25,35 and 45wt% presented chemical heterogeneity due to solute microsegregation during solidification. The values of elastic modulus measured by nanoindentation decreased as the niobium content increased, both in the laser modified zones and in the sintered substrates. The values of nanohardness remained constant within the results' statistical variation / Mestrado / Materiais e Processos de Fabricação / Mestra em Engenharia Mecânica

O nióbio possui potencial para ser um metal de grande aplicabilidade, tanto na engenharia como na área médica; porém a literatura médica a respeito deste material é escassa. Para que o nióbio de pureza 97,47% possa ser utilizado como material de implante e permita a osteointegração se faz necessário avaliá-lo quanto a sua biocompatibilidade e potencial de mineralização. Para tanto é importante compreender os eventos celulares e moleculares que ocorrem na interface nióbio-célula. Neste estudo foram utilizadas as técnicas laboratoriais de Alamar Blue, coloração de Alizarin Red, assim como a expressão de genes, importantes na ocorrência de mineralização e manutenção das células osteoblásticas, utilizando a técnica de qPCR. As células em contato direto com o nióbio obtiveram atividade celular indiferente em relação ao material controle. O nióbio possibilita a aposição de depósitos de cálcio e a adesão celular em sua superfície, comprovando a osteoindução, osteocondução e osteogênese. A análise do qPCR comprovou estatisticamente pelo método Livak que o nióbio é um material com potencial de osteointegração. O entendimento dos resultados obtidos nos testes de biocompatibilidade, mineralização e expressão gênica comprovaram que o metal nióbio é biocompatível e possui propriedades osteointegrativas, pode ser indicado como um material para implante e que permite a osteointegração. / Niobium has the potential to be a metal with wide applicability in engineering and in the medical field; but the medical literature regarding the behavior of this material is scarce. It is required to evaluate the biocompatibility and mineralization of the niobium (94,47% purity) if it would be used as an implant material and osteointegrate material. Therefore, it is important to understand the cellular and molecular events that occur in the material-cell interface. In this study we used laboratory techniques of Alamar Blue, Alizarin Red staining, as well as gene expression of important genes in the mineralization and maintenance of osteoblastic cells by qPCR technique. The cells in direct contact with the niobium obtained indifferent cellular activity compared to the control material. Niobium allowed affixing calcium deposits and cell adhesion on its surface, proving its osteoinductive, osteoconductive and osteogenesis properties. The qPCR analysis proved statistically by Livak method that niobium is a material with osseointegration potential. An understanding of the biocompatibility, mineralization and gene expression led us to conclusion that the niobium metal is biocompatible and with osteointegrative properties which can be indicated as an implant material that allows osteointegration.

Este estudo teve como objetivo avaliar a citotoxicidade, biocompatibilidade e perfil osteoindutor de um novo material a base de MTA (MTA Flow) comparado ao AH plus e MTA fillapex. A viabilidade celular foi avaliada em células-tronco do ligamento periodontal pelo teste MTT. A resposta inflamatória e o perfil osteoindutor foram avaliados em tecido conjuntivo de 24 ratos machos (Rattus norvegicus albinus, Rodentia, Mammalia da linhagem Wistar), pesando entre 300 e 350g. Os animais foram divididos em 4 grupos experimentais. Foram implantados 4 tubos de polietileno no dorso de cada animal, sendo um vazio e outros três preenchidos com um dos materiais. Após 7, 30 e 60 dias, 8 animais foram mortos com anestésico inalatório. O tubo e o tecido subcutâneo adjacente foram removidos e fixados em solução de formalina a 10%. O material foi analisado histológicamente quanto ao processo inflamatório, condensação fibrosa e presença de abscesso. Posteriormente, realizou-se a análise imunoistoquímica para identificação de colágeno I, osteopontina, sialoproteina óssea e proteína morfogentica óssea-4 (BMP-4). Os dados foram analisados estatisticamente pela ANOVA, complementado pelo teste de Tukey usando SPSS 15.0. O MTA Flow mostrou não ser citotóxico e ter excelente biocompatibilidade com menor reação inflamatória no tecido subcutâneo de ratos em comparação com AH Plus e MTA Fillapex. Além disso, o MTA Flow mostrou ser capaz de estimular o processo mineralização, sendo uma vantagem em relação aos outros materiais testados. / This study aimed to evaluate the cytotoxicity, biocompatibility and osteoinductive profile of a new MTA based material (MTA Flow) compared to AH plus and MTA fillapex. Cell viability was evaluated in periodontal ligament stem cells by the MTT test. The inflammatory response and the osteoinductive profile were evaluated in the connective tissue of 24 male rats (Rattus norvegicus albinus, Rodentia, Mammalia of the Wistar line) weighing between 300 and 350g. The animals were divided into 4 experimental groups. Four polyethylene tubes were implanted on the back of each animal, one empty and another three filled with one of the materials. After 7, 30 and 60 days, 8 animals were killed with inhaled anesthetic. The tube and adjacent subcutaneous tissue were removed and fixed in 10% formalin solution. The material was analyzed histologically for the inflammatory process, fibrous condensation and presence of abscess. Subsequently, the immunohistochemical analysis was performed to identify collagen I, osteopontin, bone sialoprotein and bone morphogenetic protein-4 (BMP-4). Data were analyzed statistically by ANOVA, complemented by the Tukey test using SPSS 15.0. MTA Flow was shown to be non-cytotoxic and to have excellent biocompatibility with lower inflammatory reaction in rat subcutaneous tissue compared to AH Plus and MTA Fillapex. In addition, the MTA Flow showed to be able to stimulate the mineralization process, being an advantage over the other materials tested.

L'état de surface est l'un des paramètres les plus importants pour déterminer la biocompatibilité d'un dispositif médical implantable, tout changement à la surface une fois en contact avec les tissus corporels peut avoir un impact sur la réponse biologique (cytotoxicité, inflammation, irritation, thrombose ... etc.). Pendant le stockage, l’exsudation des additifs peut se produire à la surface des polymères et modifier leurs propriétés. Dans cette étude, nous utilisons du polyuréthane à base de cathéter (Pellethane®), en raison de ses nombreuses applications dans le domaine des dispositifs médicaux, pour évaluer l'impact d’exsudation des additifs sur la biocompatibilité. L'impact des traitements de stérilisation et d'oxydation sur le phénomène d’exsudation a été étudié. L'étude a été réalisée sur du polyuréthane utilisé dans la fabrication de cathéters sur lesquels l’exsudation de cristaux d’additifs a déjà été observée. La stérilisation par rayonnements ionisants (bêta, gamma) a été réalisée sur ce matériau et les échantillons ont été soumis à différents types de processus d'oxydation (UV, H2O2 et action des macrophages). La viabilité des cellules endothéliales a été étudiée. Une évaluation préliminaire de l'hémocompatibilité a été réalisée par la mesure de l'hémolyse du sang total, ainsi que par l'adhésion des plaquettes en contact avec les différents échantillons de PU. L'étude de la production pro-inflammatoire d'IL-alpha; et de TNF-alpha; par des macrophages en contact avec des échantillons a également été rapportée. / Surface state is one of the most important parameter determining the biocompatibility of animplantable medical device, any change on the surface once in contact with body tissues canimpact the biological response (Cytotoxicity, inflammation, irritation, thrombosis …etc). During storage, the blooming of additives may occur on the surface of polymers and modify their properties. In this study, we use (Pellethane®) catheter-based polyurethane, because of its many applications in the field of medical devices, to evaluate the impact of additives blooming on the biocompatibility. The impact of sterilizing and oxidation treatments on blooming was studied. The study was realized on polyurethane used in the fabrication of catheters on which the blooming of antioxidant crystals has been previously observed. Sterilization by ionizing radiations (beta, gamma) was performed on this material and samples were submitted to different kinds of oxidation process (UV, H2O2 and macrophages action). Endothelial cells viability was studied. A preliminary haemocompatibility evaluation was performed through the measurement of whole blood hemolysis, as well as platelet adhesion in contact with the different PU samples. The study of the pro-inflammatory IL-alpha; and TNF-alpha; production by macrophages in contact with samplesis also reported.

The diploma work deals with the preparation of biocompatible hydrophilic layers from a propane-butane mixture by plasma polymerization. Subsequent characterization of the layers was performed using both biological (antibacterial tests and biocompatibility test) and physico-chemical diagnostics (SEM, OES and surface energy determination). The theoretical part presents the basic principle of dielectric barrier discharge, its use and various types, including surface dielectric barrier discharge (SDBD), which was used during deposition. Next, cell cultures, cell morphology and clarification of the term biocompatibility were described. At the end of the theoretical part, all used during the experimental part of the diagnostics were also described. In the experimental part, the procedure of deposition of hydrophilic layers and the overall apparatus, which was used during deposition, were presented. Prior to the characterization of the samples, the discharge was diagnosed using optical emission spectroscopy. Furthermore, the level of hydrophilicity of the layers and their elemental composition on the surface was determined. Biological tests for biocompatibility and antibacterial properties provided information on the viability of the cells on the layers and their antibacterial effects.

Nanodiamond is currently one of the most researched materials in the field of regenerative medicine in the study of treatment of neurodegenerative diseases. Due to direct interaction of this material with nerve tissue, it needs to be biocompatible with primary neurons. Furthemore, it is desirable for the used material to induce cell adhesion and stimulate the adherent cells to regeneration. This work evaluates the biocompatibility of porous boron-doped diamond layers with the culture of primary neurons. We compared the effect of diamond surface treatment by poly- D-lysine (PDL) coating on the adhesion and prosperity of the primary neuronal culture. We found that the tested nanodiamond layers are biocompatible with the primary neuronal culture. We further conclude that the PDL coating slightly increases the rate of cell adhesion to the surface but on the other hand induces greater adhesion of glial cells than the surface without PDL coating. Key words: nanodiamond, biocompatibility, adhesion, neurons

Orientador: Francine Benetti / Resumo: Introdução: Novas formulações de materiais vítreos apresentaram atividade antibacteriana e à indução a osteogênese. Objetivos: O objetivo deste estudo foi avaliar a citotoxicidade e a biocompatibilidade de soluções irrigadoras produzidas a partir de novas formulações de biovidros, o F18 (biovidro experimental) e o F18 com Cobalto (F18-Co; biovidro experimental dopado com cobalto), comparadas à água de cal, obtida a partir de solução com hidróxido de cálcio (Ca(OH)2). Materiais e métodos: O F18 foi preparado e moído, e parte deste foi dopado com cobalto. Soluções irrigadoras foram preparadas com cada material (1:10 de pó para água), formando os grupos F18, F18-Co e Ca(OH)2. Células L929 foram cultivadas, e a viabilidade celular avaliada a partir de diluições das soluções irrigadoras (não diluída, ½, ¼, 1/8 e 1/16 diluição) pelo teste MTT, após 24 e 48 horas. Tubos de polietileno foram preenchidos com esponjas de fibrina e embebidos nas soluções, e tubos embebidos em soro fisiológico serviram de controle. Os tubos foram implantados no dorso de 16 ratos. Após 7 e 30 dias (n = 8), os ratos foram eutanasiados, e os tubos com o tecido circundante foram processados para coloração de hematoxilina-eosina (H.E.) e análise da inflamação através de escores. Os dados paramétricos (citotoxicidade) foram submetidos aos testes de normalidade para definir o teste estatístico a ser empregado, e os dados não-paramétricos (H.E.), foram avaliados pelos testes de Kruskal Wallis e Dunn (p < 0,05). ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: New formulations of vitreous materials showed antibacterial activity and osteogenesis induction. Objectives: The aim of this study was to evaluate the cytotoxicity and biocompatibility of irrigating solutions produced from new formulations of bioglass, F18 (experimental bioglass) and F18 with Cobalt (F18-Co; experimental bioglass doped with cobalt), compared to cobalt water lime, obtained from a solution with calcium hydroxide (Ca(OH)2). Materials and methods: The F18 was prepared and ground, and part of it was doped with cobalt. Irrigating solutions were prepared with each material (1:10 powder to water), forming groups F18, F18-Co and Ca(OH)2. L929 cells were cultured, and cell viability assessed from dilutions of irrigating solutions (undiluted, ½, ¼, 1/8 and 1/16 dilution) by the MTT test, after 24 and 48 hours. Polyethylene tubes were filled with fibrin sponges and embedded in the solutions, tubes embedded in 0.9% saline water served as controls. The tubes were implanted on the back of 16 rats. After 7 and 30 days (n = 8), the rats were euthanized, and the tubes with the surrounding tissue were processed for staining of hematoxylin-eosin (H.E.) and analysis of inflammation through scores. The parametric data (cytotoxicity) were subjected to normality tests to define the statistical test to be used, and the non-parametric data (H.E.), were evaluated by the Kruskal Wallis and Dunn tests (p < 0.05). Results: Undiluted solutions of the materials, and dilutions ... (Complete abstract click electronic access below) / Mestre

The design of biocompatible synthetic surfaces is an important issue for medical applications. Surface modification techniques provide good approaches to control the interactions between living systems and implanted materials by modifying the surface characteristics. This thesis work demonstrates the feasibility and effectiveness of the novel and low-cost electrostatic self-assembly (ESA) technique for the manufacturing of biocompatible thin film coatings. The ESA process is based on the alternating adsorption of molecular layers of oppositely charged polymers/nanoparticles, and can be applied in the fabrication of well-organized multilayer thin films possessing various biocompatible properties. ESA multilayer assemblies incorporating various biomaterials including metal oxides and polymers were fabricated, the uniformity, thickness, layer-by-layer linearity, and surface morphology of the films were characterized by UV/vis spectroscopy, ellipsometry, and AFM imaging. Preliminary biocompatibility testing was conducted, concentrating on contact angle surface characterization and the in vitro measurements of protein adsorption. The use of Fourier Transform Infrared Reflection-Absorption Spectroscopy (FT-IRAS) for the investigation of the protein adsorption behavior upon the ESA multilayer films is presented. / Master of Science

The desire to replace missing teeth with the aim to improve health and quality of life dates back to a thousand years ago. Although research on dental crown designs, materials and techniques has increased in recent years and is expected to grow in the future. In the past few decades, dental crown studies have gained high importance in dentistry due to their functionality, biocompatibility and good mechanical properties. This paper provides a comprehensive review of history and evolution of dental crowns. The goal of this study is to understand the dental crown materials and the differences in their properties with goals to facilitate the optimal selection and to support further development. It also describes the different methods by which wear is tested on these crowns. Finally, it describes the current technologies used for the analysis, and a comparative study is performed on various dental crown materials and it is demonstrated that the wear resistance is different for different materials.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21343号 / 医博第4401号 / 新制||医||1031(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 平井 豊博, 教授 松田 秀一, 教授 別所 和久 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM