Dissertations / Theses: 'Fibroina'

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Nogueira, Grinia Michelle. "Hidrogeis e filmes de fibroina de seda para fabricação ou recobrimento de biomateriais." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267124.

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Orientador: Marisa Masumi Beppu
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Hidrogéis e filmes de fibroína de seda foram preparados e caracterizados com o objetivo de avaliar sua potencial aplicação no campo de biomateriais. Hidrogéis foram obtidos durante a etapa de diálise da solução de fibroína de seda e suas propriedades físicas, químicas, citotoxicidade e potencial de calcificação in vitro foram determinados. Esses materiais apresentaram estrutura tridimensional porosa com resistência mecânica à compressão relativamente alta e grande potencial de calcificar in vitro, sendo possíveis candidatos à aplicação na área de regeneração óssea. Filmes de fibroína de seda com quitosana foram preparados utilizando-se a técnica "Layer-by-Layer". Com esta técnica, foi possível depositar filmes anisotrópicos, com fibras alinhadas na superfície de substratos de silício. Como os biopolímeros em estudo são conhecidamente biocompatíveis, o alinhamento de fibras na superfície do substrato poderia ser explorado como um meio de guiar a adesão e proliferação celular ou ainda agregar resistência mecânica a outros filmes poliméricos. Filmes de fibroína de seda foram também empregados para recobrir pericárdio bovino utilizado na fabricação de válvulas cardíacas. Amostras recobertas com fibroína de seda foram avaliadas quanto à sua propensão à calcificação in vitro e os filmes foram testados quanto a sua citotoxicidade e potencial de adesão e crescimento de células endoteliais. Os resultados indicaram que filmes de fibroína de seda não apresentam citotoxicidade, são compatíveis com células endoteliais e não induzem a calcificação do pericárdio bovino recoberto durante os testes in vitro. Assim, o recobrimento com fibroína de seda pode ser uma alternativa de tratamento do pericárdio bovino para funcionalização da sua superfície. Dos resultados apresentados, concluiu-se que tanto hidrogéis como filmes derivados de fibroína de seda podem ser aplicados no campo de biomateriais, sejam como matrizes para reconstituição óssea, ou filmes para recobrimento e funcionalização da superfície de materiais.
Abstract: Silk fibroin hydrogels and films were prepared and characterized in order to investigate their potential application in the biomaterials field. The hydrogels were obtained during the dialysis step and their physical and chemical characteristics, cell toxicity and compatibility and potential to calcify in vitro were investigated. Those materials presented a porous tridimensional structure, mechanical strength and ability to deposit calcium phosphate crystals during in vitro calcification tests; therefore, silk fibroin hydrogels can probably be used in the bone regeneration field. Silk fibroin films were obtained by using the Layer-by-Layer technique. Bidirectional alignment of silk fibroin fibers was designed by adjusting the substrate position during the dipping process. A potential application to films with alignment of fibers is to guide cell adhesion and proliferation, since the biopolymers used to build the films are known as biocompatible materials. Silk fibroin films were also used to coat bovine pericardium used to fabricate cardiac valves. The coated samples were characterized by in vitro calcification tests and biocompatibility of silk fibroin films was evaluated by citotoxicity tests and their ability to adhere and grow of endothelial cells. The results showed that silk fibroin films are biocompatible and do not induce calcification during in vitro calcification tests, being suitable to coatand functionalize bovine pericardium surface. From the presented results, it can be concluded that silk fibroin hydrogels and films are suitable materials to be explored in the biomaterials field, for bone regeneration or biomaterials surface coating.
Doutorado
Engenharia de Processos
Doutor em Engenharia Química

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Chiarapini, Giordano. "La fibroina della seta come biomateriale per la medicina neurorigenerativa." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/6249/.

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Una delle grandi sfide della medicina moderna e dell’ingegneria biomedica è rappresentata dalla rigenerazione e il recupero dei tessuti nervosi. I danni al Sistema Nervoso Centrale (SNC) e Periferico (SNP) provocano effetti irreversibili e influiscono sulla qualità della vita dei pazienti. L’ingegneria tissutale è stata definita come “un campo interdisciplinare che applica i principi dell’ingegneria e delle scienze della vita per lo sviluppo di sostituti biologici che ripristinino, mantengano, o migliorino la funzione di un tessuto o di un intero organo” (Langer R et al, 1993). Lo sviluppo dei biomateriali, i progressi scientifici nel campo delle cellule staminali e dei fattori di crescita, nonché le migliorie nelle tecniche di differenziazione e del rilascio dei farmaci offrono nuove opportunità di sviluppo terapeutico. Sono stati infatti creati tessuti in laboratorio attraverso la combinazione di matrici extracellulari ingegnerizzate, comunemente definite scaffold, cellule e molecole biologicamente attive. Tali “impalcature”, forniscono un supporto fisico e biochimico alla crescita delle cellule nervose. In quest’ottica si configura come essenziale il contributo della seta e di una sua particolare molecola: la fibroina. Quest’ultima grazie alle specifiche caratteristiche di biocompatibilità, lenta degradabilità e alle notevoli proprietà meccaniche, è stata ampiamente studiata, in anni recenti, per nuove applicazioni in ambito biomedico, come nel caso dell’ingegneria dei tessuti e del rilascio di farmaci. La fibroina della seta utilizzabile in vari formati quali film, fibre, reti, maglie, membrane, gel e spugne supporta l'adesione, la proliferazione e la differenziazione in vitro di diversi tipi di cellule. In particolare studi recenti indicano che la seta ha una buona compatibilità per la crescita di cellule neuronali dell'ippocampo. In questo elaborato saranno presentate le caratteristiche della fibroina della seta come biomateriale, con particolare riferimento all’ingegnerizzazione e al processo di fabbricazione degli scaffold finalizzati al supporto della rigenerazione cellulare – neuronale in caso di insulti traumatici, acuti e/o cronici del Sistema Nervoso.

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Rojas, Jose Eduardo Ulloa. "Preparation and characterization of fibroin hydrogels for potential application in photodynamic therapy." reponame:Repositório Institucional da UFABC, 2017.

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Orientador: Prof. Dr. Wendel Andrade Alves
Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Nanociências e Materiais Avançados, 2017.
A pesquisa em materiais naturais aumentou notavelmente nos últimos anos devido à oportunidade de combinar biocompatibilidade com propriedades físicas, mecânicas e químicas excepcionais, o que seria árduo para obter seguindo uma rota sintética. Entre estes polímeros naturais, a fibroína de seda é atraente por sua transparência óptica, excelente robustez mecânica e compatibilidade com sistemas vivos, com a formação de produtos de degradação não inflamatória. Neste estudo, fomos capazes de formar hidrogéis translucidos a partir de fibras de seda crua em diferentes concentrações e usamos como matriz para incorporar uma molécula fotossensível : sódio (4,4 ', 4' '- (20- (4- (3-carboxipropanamido ) Fenil) porfirina-5,10,15-triil) tribenzenossulfonato - para uso futuro na terapia fotodinâmica. Os hidrogéis obtidos foram caracterizados por diferentes técnicas de reologia e análise de espectrofotometria para estudar os fatores envolvidos na formação do hidrogel e para obter informações sobre propriedades da fibroína da seda (SF) após a adição da molécula de porfirina na matriz. O conjunto de resultados obtidos mostrou que os hidrogéis SF têm um comportamento de desbaste de cisalhamento, onde a viscosidade do gel diminui com o aumento da taxa de cisalhamento e que pode ser classificado como materiais tixotrópicos, o que significa que a estrutura do material precisa de tempo para se recuperar após a deformação de cisalhamento da experiência. Além disso, observamos que a estrutura secundária da fibroína não é afetado pela adição de porfirina em qualquer concentração, foi confirmado pelo sinal negativo de Cotom em torno de 220 nm nos espectros de dicroísmo circular. As nanofibras de fibroína porfirina híbridas foram capazes de gerar oxigênio singlete após a gelificação, e provamos que os hidrogéis de fibroína de seda são uma excelente matriz para encapsular outras moléculas para aplicação em terapia fotodinâmica e terapia fototérmica, levando à formação de nanoestruturas de péptido auto-montadas com efeitos fototerapêuticos controláveis.
The research in to natural materials has notably increased in recent years due to the opportunity of combining biocompatibility with exceptional physical, mechanical, and chemical properties, which would be arduous to obtain following a synthetic route. Among these natural polymers, silk fibroin is attractive because of its optical transparency, outstanding mechanical robustness and compatibility with living systems, with the formation of non-inflammatory degradation products. In this study, we were capable to form translucid hydrogels from raw silk fibers at different concentrations and used them as matrix to incorporate a photosensitive molecule - sodium (4,4',4''-(20-(4-(3- carboxypropanamido) phenyl) porphyrin-5,10,15-triyl) tribenzenesulfonate - for future use in photodynamic therapy. The obtained hydrogels were characterized by different rheology techniques and spectrophotometry analysis to study the factors that are involved in the formation of the hydrogel, and to have information about silk fibroin (SF) properties after adding the porphyrin molecule to the matrix. The set of obtained results showed that the SF hydrogels have a shear thinning behavior, where the viscosity of the gel decrease whit the increase of the shear rate, and that it can be classified as thixotropic materials. This mean that the structure of the material needs time to recover after experience shear deformation. Also, we observed that the secondary structure of the fibroin is not affected by the addition of porphyrin in any concentration, it was confirmed by the negative Cotton signal around 220 nm in the circular dichroism spectra. The hybrid porphyrin-fibroin nanofibers were capable to generate singlet oxygen after gelification, and we proved that silk fibroin hydrogels are an excellent matrix to encapsulate other molecules to application in photodynamic therapy and photothermal therapy, leading to the formation of selfassembled peptide nanostructures with controllable phototherapeutic effects.

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Márquez, Maqueda Augusto. "Alginate and silk fibroin based technologies for biosensing." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670117.

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A causa de el fort impacte de la diabetis com a malaltia d’extensió mundial ia les perspectives d’increment en el nombre de persones afectades durant els propers anys, especialment en països subdesenvolupats, hi ha una gran necessitat de producció de sistemes de detecció i quantificació de glucosa, que puguin ser implementats en dispositius portables robustos, miniaturitzats, de baix cost i llarga durada, tipus Point of Care (POC). En aquest sentit, en aquesta tesi es proposa l’ús de biomaterials d’origen natural, com l’alginat i la fibroïna de seda, procedents de l’alga bruna (classe Phaeophyceae) i de l’cuc de seda (Bombyx mori) respectivament, i la seva combinació amb tecnologies de microfabricació per a la producció d’una nova generació de dispositius POC.
Debido al fuerte impacto de la diabetes como enfermedad de extensión mundial y a las perspectivas de incremento en el número de personas afectadas durante los próximos años, especialmente en países subdesarrollados, existe una gran necesidad de producción de sistemas de detección y cuantificación de glucosa, que puedan ser implementados en dispositivos portables robustos, miniaturizados, de bajo coste y larga duración, tipo Point of Care (POC). En ese sentido, en esta tesis se propone el uso de biomateriales de origen natural, como el alginato y la fibroína de seda, procedentes del alga parda (clase Phaeophyceae) y del gusano de seda (Bombyx mori) respectivamente, y su combinación con tecnologías de microfabricación para la producción de una nueva generación de dispositivos POC.
Due to the impact of diabetes as a worldwide disease and the expected increment in the number of people affected in the following years, especially in underdeveloped countries, there is a need for the production of precise and long-life glucose biosensors to be implemented in simple, low-cost, robust, miniaturized and portable point of care systems. In that sense, this thesis proposes the use of biomaterials of natural origin, such as alginate and silk fibroin, from brown algae (Phaeophyceae class) and silkworm (Bombyx mori) respectively, and their combination with microfabrication technologies for the production of the new generation of electrochemial and optical point of care devices.

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Weska, Raquel Farias. "Estudo da esterilização e da calcificação in vitro de membranas de fibroina de seda para a aplicação como biomaterial." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267024.

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Orientador: Marisa Masumi Beppu
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: A fibroína de seda tem sido amplamente explorada para aplicações biomédicas, devido à sua biocompatibilidade, biodegradabilidade e mínima reação inframatória. A esterilização é uma etapa fundamental no processamento de biomateriais, e não deve alterar de forma negativa as propriedades funcionais dos dispositivos médicos. Estudos recentes verificaram que a fibroína pode ser utilizada como suporte para mimetizar a biomineralização, promovendo o crescimento de cristais de hidroxiapatita. O objetivo deste trabalho foi analisar a influência de diferentes métodos de esterilização nas características físicas, mecânicas e biológicas de membranas densas e porosas de fibroína de seda, e também estudar a possibilidade de aplicação de membranas de fibroína como biomaterial, pelo estudo da calcificação in vitro. Membranas densas e porosas de fibroína foram esterilizadas por radiação ultravioleta, etanol 70%, autoclave, óxido de etileno e radiação gama, e foram analisadas por MEV, FTIR-ATR, DRX, testes mecânicos e de citotoxicidade indireta. Para os ensaios de calcificação in vitro, as membranas de fibroína foram imersas em SBF por sete dias, e caracterizadas por MEV e EDX. Os resultados de esterilização mostraram que nenhum método ocasionou degradação das membranas ou a formação de produtos citotóxicos. Os métodos que utilizaram solvente orgânico, e aumento de umidade e/ou temperatura (etanol 70%, autoclave e óxido de etileno) tornaram as membranas densas mais cristalinas, e as membranas porosas mais estáveis, o que pode ser aproveitado quando se deseja que as membranas apresentem uma degradação in vivo mais lenta, dependendo da aplicação. Os resultados obtidos de calcificação in vitro indicaram que a fibroína pode induzir a calcificação, pela formação de depósitos de fosfato de cálcio com relações de Ca/P similares à da hidroxiapatita e seus precursores. A membrana porosa apresentou maior tendência à calcificação, quando comparada com a membrana densa, devido à sua rugosidade e porosidade, podendo desta forma ser considerada para aplicação em regeneração óssea.
Abstract: Silk fibroin has been widely explored for many biomedical applications, due to its biocompatibility, biodegradability and minimal inflammatory reactions. Sterilization is a fundamental step in biomaterials processing, and it must not alter in a negative way the functionality of medical devices. On the applicability of fibroin as a biomaterial, recent studies verified that fibroin can be used as a scaffold for mimicking biomineralization, promoting the growing of hydroxyapatite crystals. The aim of this study was to analyze the influence of different sterilization methods on physical, mechanical and biological characteristics of dense and porous silk fibroin membranes, and also to study the application of the fibroin membranes as biomaterials, through in vitro calcification studies. Dense and porous fibroin membranes were sterilized by ultraviolet radiation, 70% ethanol, autoclave, ethylene oxide and gamma radiation, and were analyzed by SEM, FTIR-ATR, XRD, mechanical and cytotoxicity tests. For in vitro calcification experiments, the fibroin membranes were soaked in SBF for seven days, and characterized by SEM and EDS. The results for sterilization indicated that none of the methods caused degradation or formation of cytotoxic substances. The methods that used organic solvent, and increase of humidity and/or temperature (70% ethanol, autoclave and ethylene oxide) increased the crystallinity of the dense membranes, and stabilized the porous membranes, characteristics that may be utilized when a slow in vivo degradation is desired, depending on the application. The calcification experiments indicated that silk fibroin may induce calcification, by forming calcium phosphate deposits with a Ca/P ratio similar to that of hydroxyapatite and its precursors. Porous membranes presented higher tendency to calcify, when compared to dense membranes, due to its surface roughness and high porosity, indicating that porous silk fibroin membranes may be considered for application in bone regeneration.
Mestrado
Engenharia de Processos
Mestre em Engenharia Química

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Martini, Mara. "Simulazione delle proprietà morfologiche e strutturali di materiali biologici ed organici per dispositivi elettronici ed optoelettronici." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15555/.

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Recentemente l’elettronica organica sta attraendo grande interesse, a causa della possibilità di produrre dispositivi a basso costo, flessibili, di grandi dimensioni e leggeri. In più sono sempre più numerosi gli studi che riportano l’utilizzo di uno o più materiali biologici nella fabbricazione di questi dispositivi, dal momento che crescono le richieste, soprattutto in ambito medico e ambientale, di strumenti capaci di interagire con il corpo umano e l’ambiente esterno. Per cercare quindi di potenziare l’efficienza di dispositivi organici e bio-organici è utile ottimizzare le proprietà elettroniche e morfologiche dei materiali costituenti il dispositivo. Per fare ciò risultano molto utili studi computazionali che permettono di comprendere la correlazione tra proprietà morfologiche ed elettroniche. In questo lavoro di tesi sono stati studiati due materiali: la fibroina, proteina maggioritaria estratta dalla seta del baco Bombyx mori, come materiale dielettrico e il PTCDI-C13, un composto organico derivato dalla perilene diimmide, come materiale semiconduttore. Questi due materiali formano gli strati attivi di un bio-OFET. Al fine di investigare le proprietà morfologiche strutturali di questi materiali sono state utilizzate le tecniche di simulazione di dinamica molecolare. Sono stati effettuati studi morfologici sulle rugosità superficiali e strutturali, analizzando le proprietà morfologiche e strutturali dei materiali e delle relative interfacce, anche in relazione ai vari trattamenti termici simulati al fine di poter correlare il processing al miglioramento delle performance globali. In più, dal momento che il PTCDI-C13 è un materiale cristallino, si è cercato anche di stabilire l’ordine locale degli aggregati di PTCDI-C13 depositati su fibroina. Le simulazioni hanno inoltre evidenziato un miglioramento della morfologia della superficie esposta rispetto alla fibroina isolata, marcando il ruolo fondamentale che ha questo strato nell’architettura OFET.

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Aciari, Juliana Raquel Frigo. "Preparação de micropartículas de fibroína da seda calcificadas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/82/82131/tde-28112013-091351/.

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A calcificação ocorre pela formação de depósitos de cálcio em diferentes matrizes envolvendo fatores mecânicos, químicos e biológicos. Alguns compósitos, polímeros e proteínas são utilizados na formação de matrizes por promover maior eficiência no processo de mineralização. Estima-se que a fibroína da seda apresente também esta finalidade. A fibroína é uma proteína fibrosa extraída do casulo do bicho-da-seda (Bombyx mori), que pode ser processada como filme, membrana, esponja, pó, gel e aplicada em ossos e cartilagens, enxertos vasculares, reparação de nervos e córnea, como sistema de liberação de drogas, suturas, ligamentos, peles, tendões e substrato para cultura de células. Nesse trabalho houve a preparação de micropartículas de fibroína da seda através de dois procedimentos distintos, um por borrifamento em N² e outro por borrifamento em Na2HPO4 e o processo de calcificação realizado foi por imersão alternada de soluções tamponadas de cálcio e fosfato. As caracterizações realizadas foram Espectroscopia de Absorção no Infravermelho (FT-IR), Análise Termogravimétrica (TGA), Microscopia Eletrônica de Varredura (MEV), Espectroscopia de Energia Dispersiva (EDS) e Calorimetria Exploratória Diferencial (DSC). Os resultados obtidos mostraram que a calcificação das micropartículas de fibroína ocorre pelas duas metodologias empregadas. O teor de calcificação foi de aproximadamente 29% para micropartículas borrifadas em N² e de aproximadamente 80% para as micropartículas borrifadas em Na2HPO4. As micropartículas de fibroína calcificadas, não apresentaram transição térmica até a temperatura de 120°C, possibilitando a esterilização em autoclave a seco.
Calcification occurs by the formation of calcium deposits in different matrices involving mechanical factors, chemical and biological. Some composites, polymers, and proteins are used in forming matrices to promote higher efficiency in the process of mineralization. It is estimated that the silk fibroin also present for this purpose. The fibroin is a fibrous protein extracted from silkworm cocoon silkworm (Bombyx mori), which can be processed as film, membrane, sponge, powder, gel and applied in bone and cartilage, vascular grafts, nerve repair and corneal as a delivery system for drugs, sutures, ligaments, skins, tendons and substrate for cell culture. In this work was the preparation of microparticles of silk fibroin by two different procedures, sputter under N² and in other sputter Na2HPO4 and calcification process was performed by immersion of alternating buffered solutions of calcium and phosphate. The characterizations were performed Absorption Spectroscopy Infrared (FT-IR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Differential Scanning Calorimetry (DSC). The results showed that the calcification of fibroin microparticles occurs by the two methodologies. The calcified fibroin microparticles showed no thermal transition temperature to 120°C, enabling autoclaving of the microparticles dry

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Bexiga, Natália Marchesan. "Preparo e avaliação comparativa das propriedades físico-químicas de hidrogéis de fibroína de seda com conteúdo variado de sericina obtidos a partir dos cloretos de cálcio e lítio em sistemas distintos de solventes." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-19092014-093819/.

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A fibroína de seda é uma proteína sintetizada pela espécie Bombyx mori, popularmente conhecida como bicho-da-seda. O casulo de Bombyx mori é composto por fibras de fibroína e pela sericina, responsável por unir os fios de fibroína. A fibroína é um polímero natural bastante versátil e pode ser processada de maneira a formar materiais como filmes, microesferas e hidrogéis. Os hidrogéis são redes tridimensionais formadas por macromoléculas e capazes de absorver grande quantidade de água sem perder sua integridade estrutural. Devido à características como biocompatibilidade, elevado teor de água e boas propriedades de difusão de oxigênio e nutrientes, os hidrogéis são amplamente utilizados em pesquisa biomédica. A fibroína é biodegradável, termicamente estável, altamente cristalina, flexível, resistente à tração, além de insolúvel em água e na maioria dos solventes orgânicos. A fibroína derivada das sedas Frison Extra e Meada 21 Denier foi separada da sericina pelo processo de degomagem, onde as fibras de seda foram imersas em soluções alcalinas e submetidas à aquecimento com posterior remoção de sericina. Os fios de fibroína foram dispersos nas soluções de CaCl2:H2O, LiCl:H2O e LiCl:EtOH:H2O. Diferenças nos tempos de dispersão para amostras distintas degomadas ou não foram observadas, bem como para cada um dos sistemas salino/solvente empregados. Após o processo de dispersão da fibroína as dispersões obtidas foram caracterizadas quanto à textura e reologia. As amostras não degomadas apresentaram maior firmeza e aumento do módulo elástico G\'. Algumas amostras contendo sericina ou etanol apresentaram comportamento newtoniano. Em uma segunda etapa, as amostras foram dialisadas para a produção do hidrogel e em seguida liofilizadas. Não houveram diferenças entre os tempos de gelificação para amostras distintas. Finalmente objetivou-se a caracterização dos hidrogéis obtidos por meio de ensaios termogravimétricos, difratométricos, espectrofotométricos e microscópicos. Todos os hidrogéis de fibroína de seda apresentaram alta resistência térmica, com presença predominante da conformação em folha-β da fibroína. Morfologicamente, os hidrogéis obtidos a partir de dispersões em LiCl:EtOH:H2O e CaCl2:EtOH:H2O apresentaram aspecto de rede enovelada, enquanto que os hidrogéis oriundos de dispersões em LiCl:H2O apresentaram estrutura lamelar.
The silk fibroin is a protein synthesized by Bombyx mori species, popularly known as silkworm silk. The Bombyx mori cocoon is composed of fibroin fibers and the sericin protein, which is responsible for joining the fibroin yarns. The fibroin is a quite versatile natural polymer and can be processed to form materials such as films, microspheres and hydrogels. Hydrogels are three-dimensional networks formed by macromolecules and capable of absorbing large quantities of water without losing their structural integrity. Due to biocompatibility, ability to mimic biological tissues, high water content and good diffusion properties of oxygen and nutrients, hydrogels are widely used in biomedical research. The fibroin is biodegradable, thermally stable, highly crystalline, flexible and tensile resistant. Besides, it is insoluble in water and in most organic solvents. The fibroin from Frison Extra and Meada 21 Denier silks was separated from the sericin by the degumming process, whereby the silk fibers were immersed in alkaline solutions and subjected to heating with subsequent dissolution and removal of sericin. Fibroin yarns were dispersed in various solutions: CaCl2:H2O; LiCl:H2O; and LiCl:EtOH:H2O. It was observed that according to the fibroin type and solvent solution used the time to achieve dispersion varied. Texture and rheology were determined for every sample after dispersion. All non-degummed samples had shown increased firmness and elastic module G\'. It was observed that the samples presented a wide behavior range, some that contained sericin or ethanol presented Newtonian behavior. Subsequently the samples were dialyzed to obtain the hydrogels and lyophilized. All samples (with exception of two) have formed hydrogels in a 24 hours period. The lyophilized hydrogels were analyzed by thermogravimetry, diffractometry, spectrophotometry and microscopy. All silk fibroin hydrogels presented high thermic resistance with β-sheet predominance. Morphologically, all hydrogels obtained from LiCl:EtOH:H2O and CaCl2:EtOH:H2O solutions had shown entangled aspect wile hydrogels from LiCl:H2O solutions had shown lamellar structures.

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Pugina, Roberta Silva. "Estudo de fibroína dopada com terras raras para potenciais aplicações fotônicas." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-28032018-131311/.

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A fibroína da seda (SF) é uma proteína estrutural encontrada nos casulos do Bombyx mori e que possui propriedades potencialmente aplicáveis em fotônica. Esta matriz biocompatível é um substrato interessante para diferentes íons ou moléculas; além disso, o seu índice de refração variável permite que fótons sejam guiados neste material, possibilitando seu uso como guias de ondas biocompatíveis e reabsorvíveis, que pode ser utilizado para fornecer energia ótica para diversas aplicações, por exemplo, terapia ou imagem dentro de tecidos vivos. A sua boa adequação em sistemas ópticos deve-se principalmente a propriedades como: ser mecanicamente robusta, apresentar superfícies muito lisas, altamente transparentes (> 95%) em toda a região visível do espectro e ser modelável. Além disto, há uma característica adicional: a viabilidade de funcionalização bioquímica, o que pode conferir uma maior versatilidade a estes dispositivos. Já os íons terras raras (TR) possuem um papel amplamente conhecido no ramo da fotônica; porém, não há nenhum estudo envolvendo a produção de luz em SF dopada com íons TR, e a combinação das propriedades mecânicas e óticas desta matriz com a multifuncionalidade destes íons pode ser uma forma de se produzir dispositivos fotônicos novos e distintos. Desta forma, o presente trabalho teve como objetivo estudar a estrutura da matriz de SF na presença de diferentes íons TR (Eu3+ e Tb3+), bem como a interação existente entre os aminoácidos que constitui a matriz e estes íons. Os resultados apresentados nesta dissertação mostraram as interações TR-SF e suportam os mecanismos de transferência de energia para excitação de diferentes íons TR nesta matriz, sendo importante para futuras aplicações em fotônica
Silk fibroin (SF) is a structural protein found in Bombyx mori cocoons and has properties that are potentially applicable in photonics. This biocompatible matrix is an interesting substrate for different ions or molecules. Furthermore, its variable refractive index allows for photons to be guided in this material enabling their use as biocompatible and resorbable waveguides, which can be used to provide optical energy for various applications, e. g., therapy or imaging into living tissue. Its suitability in optical systems is mainly due to its properties such as: being mechanically robust, presenting very smooth surfaces, highly transparent (> 95%) throughout the visible region of the spectrum and being moldable. In addition, there is an extra feature: the possibility of biochemical functionalization, which may confer greater versatility to these devices. On the other hand, rare earth ions (RE) play a widely known role in the field of photonics. However, there is no studies involving the production of light in doped SF with RE ions and the combination of the mechanical and optical properties of this matrix with the multifunctionality of these ions can be a way to produce new photonic devices. Thus, the aim of the present work was to study the SF matrix structure in the presence of different RE ions (Eu3+ and Tb3+) as well as the interaction between the amino acids from the matrix and these RE ions. The results presented in this manuscript have characterized the RE-SF interactions and supported the mechanisms of energy transfer for excitation of different RE ions in this matrix being important for future applications in photonics

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Caetano, Laís Galvão [UNESP]. "Propriedades ópticas de membranas à base de polímeros naturais e nanopartículas de carbono." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/148739.

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A fibroína da seda extraída dos casulos do bicho-da-sêda é um co-polímero particularmente atraente para aplicações em dispositivos fotônicos e opticoeletrônicos devido a sua transparência óptica, biocompatibilidade e propriedades mecânicas. Esta tese apresenta a obtenção de suspensões e filmes iridescentes-luminescentes de fibroína contendo nanopartículas luminescentes de carbono (“carbon dots”) obtidos a partir de carvão vegetal. As nanopartículas luminescentes de carbono apresentam biocompatibilidade, baixa toxicidade, propriedades de fotoluminescência interessantes e possibilidade de modificação da superfície. Redes de difração foram produzidas nestes filmes utilizando como molde um DVD comercial. Os materiais obtidos foram caracterizados por um conjunto de técnicas de análise: Microscopia de Força Atômica (AFM), Microscopia Eletrônica de Varredura (MEV), Microscopia Eletrônica de Transmissão (MET), Espectroscopia de absorção na região do UVVis, Espectrofotometria de absorção molecular na região do infravermelho com transformada de Fourier (FTIR) e Luminescência. Medidas de luminescência mostram que os carbon dots emitem múltiplas cores entre toda a região do visível. Planos cristalinos foram observados nas imagens de MET das nanopartículas, no qual foram asssociadas a estrutura do grafite. Pela análise de UV-Vis dos carbon dots observou-se que a absorção óptica decai gradualmente à medida em que ocorre deslocamento para o vermelho e para os filmes de fibroína observou-se um ombro referente a transição eletrônica da tirosina (aminoácido de sua composição). A partir dos espectros de FTIR observou-se que não houve mudança na estrutura da fibroína após a adição dos carbon dots. As imagens de AFM e MEV comprovam a presença dos micropadrões periódicos na superfície dos filmes. Os resultados mostraram que os filmes de fibroína contendo carbono dots tem um grande potencial para a biomedicina, principalmente devido os seus parâmetros de luminescência se extenderem em toda a região do visível e por apresentar uma matriz sustentável, com excelentes propriedades ópticas e mecânicas.
Silk fibroin extracted from silkworm cocoons is a particularly attractive copolymer for applications in photonics and optoelectronics devices due its optical transparency, biocompatibility and high mechanical strength. This thesis presents the preparation of suspensions and iridescent-luminescent films of silk fibroin containing luminescent carbon nanoparticles (carbon dots) obtained from vegetal coal. Luminescent carbon nanoparticles present high biocompatibility, low toxicity, interesting photoluminescence properties and possibility of surface modification. Diffraction gratings were produced in these films using a commercial DVD as a template. The materials obtained were characterized by a set of analysis techniques: Atomic-Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), UV-Visible Spectroscopy, Fourier transform infrared spectroscopy (FTIR), and Luminescence. Luminescence measurements show that carbon dots emit light at the entire visible region. Crystalline planes were observed in the TEM images of the nanoparticles, where upon the graphite structure was associated. By analyzing the UV-Vis spectra of the carbon dots it was observed that the optical absorption gradually decreases as the red shift occurs. In the UV-Vis spectra of the silk fibroin films it was observed a shoulder referring to the electronic transition of the tyrosine (amino acid of its composition). From the FTIR spectra it was observed that there was no change in the silk fibroin structure after addition of the carbon dots. The AFM and SEM images confirm the presence of the periodic micro-patterns on the surface of the films. The results showed that the silk fibroin films containing carbon dots have a great potential for biomedicine, mainly due to its luminescence parameters extending throughout the visible region and due to a sustainable platform with excellent optical and mechanical properties.

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Silva, Robson Rosa da [UNESP]. "Novas estruturas fotônicas: I – Auto-organização de estruturas 1D de Te; II – Biopolímeros e plásticos reutilizados multifuncionais." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/141452.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Nanoestruturas unidimensionais de telúrio (Te1D) na forma de whiskers, fios e hélices foram preparados com facilidade por uma síntese em etapa única na presença de solução aquosa de Pluronic® F68 à baixas temperaturas (< 100 °C) e pressão ambiente. A forma das nanoestruturas puderam ser controladas de acordo com a cinética da reação. Estruturas empacotadas de nanowhiskers e nanofios de Te foram obtidas via auto-organização em interface líquido-líquido e pela técnica de drop-cast em substrato de Si/SiO2. Estruturas híbridas 1D foram obtidas utilizando nanoestruturas Te1D como molde de sacrifício para anexar nanopartículas metálicas ou mesmo produzir nanoestruturas 1D metálicas. Por exemplo, nanoestruturas híbridas 1D foram preparadas decorando nanofios de Te com nanopartículas de Ag em solução aquosa de poli(vinilpirrolidona). Nanoestruturas 1D de Au com forma de nódulos foram preparados por deslocamento galvânico de íons Au3+ em uma mistura de nanohélices de Te, ácido ascórbico e solução aquosa de poli(vinilpirrolidona). Além disso, nanohélices de Te foram funcionalizadas com uma camada resina resorcinol-formaldeído em condições brandas de síntese. A resina de resorcinol-formaldeído é uma via intermédia para explorar a deposição de compostos opticamente ativos tais como nanopartículas de hidroxicarbonato de Tb3+ ou nanopartículas de Au. Para aplicações práticas é essencial que estas nanoestruturas possam ser suportadas em filmes rígidos ou flexíveis de alta qualidade óptica. Filmes de polímeros naturais puros e filmes híbridos de sol-gel epóxi foram avaliados como potenciais matrizes hospedeiras para luminóforos. A fabricação de híbridos é baseada na incorporação de 3-glicidoxipropiltrimetoxissilano na solução homogênea de polímero natural com posterior secagem sobre uma superfície plana. Particularmente, filmes flexíveis de fibroína da seda e acetato de celulose e os seus híbridos derivados exibiram excelentes propriedades ópticas para hospedar compostos opticamente ativos. Por exemplo, compostos de Eu3+ emissores na região do vermelho e corantes fluorescentes foram incorporados em matriz pura de polímero e híbridos epóxi e suas propriedades ópticas foram investigadas. Laser de corantes por feedback distribuído (DFB) foram fabricados dopando grades de difração de fibroína de seda com Rodamina 6G. Devido a sua capacidade de replicar superfícies padronizadas com resolução nanométrica, grades de fibroina da seda dopadas com corante foram depositadas contra a grade de difração de uma mídia de disco compacto comercial. Lasers modificados de DFB baseados em filmes de fibroina contendo nanopartículas espalhadoras de luz de SiO2 e Ag aleatoriamente distribuídas na grade de fibroina demonstraram aumento da intensidade do laser, além de estreitamento da largura do pico de emissão. Filmes híbridos flexíveis e transparentes (> 85%) de fibroina da seda e acetato de celulose modificados com função epóxi e contendo compostos fluorescentes na região do vermelho como complexos β-dicetonato de Eu3+ e nanopartículas de YVO4:Eu3+ em baixa proporção relativa mássica (<5%) foram preparados. De maneira geral, o resultado são filmes homogêneos com funções epoxi e/ou alcoxissilano não hidrolisados disponíveis para outras modificações químicas. Devido a matéria-prima limitada de polímeros naturais para uma alta demanda de fabricação de dispositivos ópticos, é igualmente importante desenvolver materiais com base na reutilização de polímeros sintéticos. Filmes finos de poliestireno foram concebidos por dissolução de poliestireno expandido (EPS) recuperado de resíduos em D-limoneno, um solvente verde proveniente de óleos cítricos. Filmes transparentes dopados com complexos β-dicetonato de Eu3+ demonstraram excelente transparência e aptos para uso em guias de luz. Estes resultados são motivadores para a) a engenharia de nanoestruturas 1D com propriedades ópticas sintonizáveis bem como, b) desenvolvimento de híbridos flexíveis e transparentes baseados em híbridos de polímeros naturais com alta funcionalidade química ou polímeros sintéticos reciclados como potenciais matrizes hospedeiras ópticas almejadas em aplicações fotônicas.
One-dimensional Te nanostructures (Te1D) in the shape of whiskers, wires and helices were prepared by a facile one-pot synthesis in the presence of aqueous Pluronic® F68 solution at low temperatures (< 100 ºC) and ambient pressure. The shape of Te1D nanostructures could be manuvered according with the reaction kinectics. We evaluate some techniques to assemble Te1D nanostructures on the pursuit for complex nanoarchitectures. Bundles of Te nanowhiskers and nanowires were achieved by self-assembly in liquid-liquid interface or by drop-cast technique in Si/SiO2 substrates. 1D hybrid structures have been conceived by using Te1D nanostructures as sacrificial template to attach metallic nanoparticles or even produce metallic 1D nanostructures. For example, 1D hybrid nanostructures were easily prepared by decorating Te nanowires with Ag nanoparticles in aqueous solution of poly(vinylpyrrolidone). Au 1D nanostructures with nodular-like shape were prepared by galvanic displacement of Au3+ ions in a mixture of Te nanohelices, ascorbic acid and an aqueous solution of poly(vinylpyrrolidone). Furthermore, Te1D nanohelices were functionalized with a layer of resorcinol-formaldehyde resin at mild synthesis conditions. The RF resin allowed us to fashion an intermediate pathway to explore the deposition of optically active compounds like Tb3+ hydroxylcarbonate or Au nanoparticles. Seeking practical applications, these nanostructures should be hosted over rigid or flexible films possessing excellent optical properties. Pure natural polymers and epoxy sol-gel hybrids films were evaluated as potential host for luminophors. The fabrication of epoxy hybrids is based on the incorporation of 3-glycidoxypropyltrimethoxysiloxane on the homogenous solution of natural polymer with subsequent casting over flat surface. Particularly, flexible silk fibroin and cellulose acetate films and their derivative hybrids displayed excellent optical properties to host optically active compounds. For instance, red emitting Eu3+ compounds and fluorescent dyes were hosted on pure natural polymer and hybrid films and the optical features of the luminescent films were investigated thoroughly. Distributed feedback dye-lasers were fabricated by doping silk fibroin diffraction gratings with Rhodamine 6G. Owing its ability to mimic patterned surfaces at nanoscale resolution, dye-doped SF gratings were fabricated using replica-casting patterning against a commercial blank digital versatile disc as template. A modified DFB Laser based on SF films with Ag or SiO2 light scattering particles randomly distributed on the grating unveiled an enhancement of laser intensity withal narrowing of emission peak linewidth. Flexible and highly transparent SF- and CA-epoxy hybrids (> 85%) containing red fluorescent Eu3+ b-diketonate complex and YVO4:Eu3+ nanoparticles at low relative content (< 5 wt%) were tailored. In general, the outcome is homogeneous films with epoxy and/or unhydrolized alkoxysilane functions available for further chemical modification. Owing the limited feedstock of natural polymers for high demanding production of optical devices, it is equally important develop materials based on the reuse of synthetic polymers. Thin films of polystyrene were conceived by dissolving waste-recovered expanded-polystyrene (EPS) in D-limonene, a green solvent from citrus oil. Transparent EPS films doped with Eu3+ b-diketonate complex displayed excellent transparency and light waveguiding, These assertions provide a framework that motivates the research on a) engineering of 1D hybrids nanostructures with tunable optical properties and b) flexible natural polymer/epoxy hybrid with enhanced functionality or plastic recycled as potential optical hosts sought in photonic applications.
FAPESP: 2013/12367-6

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Juvenal, da Silva Raphaela. "Avaliação clínica e histomorfológica de lesões fibroósseas benignas dos maxilares." Universidade Federal de Pernambuco, 2010. https://repositorio.ufpe.br/handle/123456789/8689.

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Universidade Federal de Pernambuco
Objetivo: Analisar aspectos clínicos e histopatológicos dos casos de lesões fibro-ósseas benignas (LFOBs) dos maxilares. Método: Foi realizado um estudo retrospectivo dos 19 casos de LFOBs dos maxilares diagnosticadas no laboratório de Patologia Oral da Universidade Federal de Pernambuco no período compreendido entre 1998 e 2009. Foram avaliados dados clínicos referentes ao gênero e idade dos pacientes, localização anatômica e tempo de evolução das lesões, assim como as hipóteses diagnósticas aventadas pelos profissionais requisitantes dos exames histopatológicos. Para o estudo histomorfológico, as LFOBs foram avaliadas quanto à morfologia, grau de maturação e atividade osteoblástica do tecido ósseo. A sobreposição dos principais achados histológicos também foi analisada. Resultados: Dentre as lesões analisadas, 9 eram displasias fibrosas (DFs), 6 fibromas ossificantes (FOs) e 4 displasias ósseas (DOs), sendo 2 floridas, 1 periapical e 1 focal. Todas as LFOBs apresentaram forte predileção pelo gênero feminino e acometeram mais a mandíbula. Com relação às características histomorfológicas do tecido ósseo, a maior parte das DFs e DOs mostrou trabéculas curvilíneas com padrão não-lamelar e sem pavimentação osteoblástica. Os FOs apresentaram maior variabilidade de morfologia do tecido ósseo, com a presença de depósitos esféricos. O trabeculado exibiu atividade osteoblástica, e ambos os padrões de maturação óssea foram verificados. Quando comparadas entre si, as LFOBs apresentaram coincidência em metade dos aspectos histopatológicos analisados. Conclusões: Houve significativa similaridade entre os achados histomorfológicos avaliados. Os dados clínicos não se mostraram suficientes para realizar a distinção diagnóstica entre as lesões, o que indica deficiência de informações no preenchimento das fichas clínicas

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Soucie, Jennifer Elizabeth. "Embolization therapy for uterine fibroids, a multivariate analysis of the predictive factors of fibroid response." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62934.pdf.

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Montanha, Vanessa Camila. "Preparação e caracterização de micropartículas de colágeno ou fibroína como suporte para células-tronco." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/82/82131/tde-08012013-111744/.

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Diversos biomateriais podem ser aplicados na engenharia de tecidos, mas poucos são utilizados em contato direto com células-tronco na forma de suportes de micropartículas, devido à falta de adesão, espalhamento e toxicidade do material, de forma que os tornam inviáveis junto ao cultivo celular. Um biomaterial promissor para bioengenharia é a fibroína, proteína fibrosa presente no casulo do bicho da seda (Bombyx mori), devido à sua resistência mecânica, biocompatibilidade e mínima reação inflamatória, porém, suas caracteristicas são pouco conhecidas na literatura. O mesmo não ocorre com o colágeno que já é bastante estudado por pesquisadores e, assim como a fibroína, apresenta propriedades naturais que incluem baixa resposta imunológica, baixa toxicidade e habilidade de promover o crescimento celular, porém o uso do colágeno em sua maior parte é em forma de filmes, esponjas e membranas. Como existem poucos métodos relacionados para preparação e caracterização de micropartículas em formatos esféricos e porosos, este trabalho teve por objetivo desenvolver e caracterizar micropartículas à base de colágeno ou fibroína, tratadas ou não com glutaraldeído (GA), para ser utilizado como suporte para células-tronco mesenquimais e avaliar a citotoxicidade destes materiais em cultura celular.Nos resultados de Calorimetria Exploratória Diferencial para ambos os materiais, colágeno e fibroína quando submetidas a tratamento com GA, a temperatura de desnaturação e degradação aumenta, respectivamente. Na microscopia ótica, eletrônica de varredura e birrefringência, observa-se o aparecimento de rugosidade e poros e/ou bolhas de ar no interior das micropartículas em maior quantidade quando tratadas com GA, o que pode ser um fator positivo para aderência celular no suporte. A porcentagem de água absorvida é maior no colágeno devido às estruturas hidrofóbicas em maior quantidade na fibroína, porém, quando tratadas com GA, a absorção é estabilizada em um curto tempo em ambos os materiais. Os picos nos espectros de FTIR mostram as bandas amidas I, II e III dos materiais e as alterações sofridas quando em contato com GA e os testes de citotoxicidade que ambos materiais tratados ou não, são atóxicos, mas o desenvolvimento celular nas micropartículas de fibroína é mais lento e diminui quando tratados com GA, por possuir mais estruturas ordenadas na forma de -folha quando se necessita de um crescimento mais controlado das células nas micropartículas.
There are several biomaterials can that be used in tissue engineering, but few are used in direct contact with stem cells like scaffold in the microparticle form, because of the lack of adhesion, spreading and toxicity of the biomaterial, in order to make them nonviable in the cell culture. A promising biomaterial for bioengineering is fibroin, a fibrous protein present in the fibers of silkworm (Bombyx mori) cocoon, because of its mechanical strength, biocompatibility and minimal inflammatory reaction; however, little is still described in the literature. Not so with the collagen that is already well studied by researchers and as the fibroin, has natural properties that include low immune response, low toxicity and ability to promote cell growth, but the use of collagen is mostly in form of films, sponges and membranes. As there are few methods reported for preparation and characterization of microparticles in spherical shapes and porous, this study aimed to develop and characterize microparticles based on collagen or fibroin, treated or not with glutaraldehyde (GA), to be used as a support for cells mesenchymal stem cells and evaluating the cytotoxicity of these materials in cell culture.In the results of Differential Scanning Calorimetry (DSC) curves for both materials, collagen and fibroin when subjected to treatment with GA, the denaturation and degradation temperatures increases, respectively. In Optical Microscopy, MSCanning electronic Microscopy and Birefringence results, it is observed the onset of surface roughness and porosity and or air pockets within the microparticles in greater quantity when treated with GA, which may be a positive factor for cell attachment on the support. The percentage of water absorbed is greater in the collagen structures due to more hydrophobic structure than silk fibroin, but when in treated with GA, absorption is stabilized in a shorter time in both materials. The peaks in FTIR spectra show bands amide I, II and III of the materials and the changes suffered when in contact with GA and cytotoxicity tests are non-toxic to both biomaterials treated or not, however, in the growth of cells, the fibroin microparticles is slower and decreases when treated with GA, due to its more ordered structure in the form of -sheet and more spherical than collagen due to its more ordered -sheet structures, which may be very interesting when it needs a more controlled growth of cells on microspheres.

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Kravicz, Marcelo Henrique. "Preparação e caracterização de membranas obtidas a partir de blendas de fibroína de seda e poli(álcool vinílico)." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/82/82131/tde-28062013-153000/.

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A fibroína da seda (SF) é uma proteína fibrosa, com caráter hidrofóbico, produzida pelo bicho-da-seda (Bombyx mori L.), cuja produção e armazenamento ocorre em glândulas especializadas antes do processo de fiação em fibras. Recentemente, soluções de fibroína de seda regenerada (RSF) têm sido utilizadas para formar diferentes materiais tais como géis, membranas, filmes e esponjas, para aplicações médicas (Medicina Regenerativa) e em sistemas de liberação de fármacos. Neste trabalho, procuramos estudar o comportamento da solução RSF 2% com adição de 0,25, 0,5 e 1% de PVA (polímero sintético e hidrofílico) por meio de ensaios de reologia dos géis obtidos (SF:PVA), e caracterização das membranas obtidas por meio da secagem em moldes dos géis. Os ensaios de reologia mostraram uma inversão de módulos, com transição de caráter elástico (G\') para viscoso (G\") para SF1 a 3%, entre 230 e 900% de deformação (\'gama\'); transição de caráter viscoso para elástico para as blendas SF:PVA 0,5 e 1% em ensaio de frequência (\'ômega\'). Com o aumento de temperatura, todas as blendas mantiveram seus comportamentos elástico (SF:PVA 0,25%) e viscoso (SF:PVA 0,5 e 1%) até 49 - 51°C, com transição líquido-gel; o aumento dos módulos G\' e G\"com o resfriamento das amostras ocorreu em todas as blendas. As membranas obtidas das blendas SF:PVA tiveram maior absorção de tampão fosfato salino (PBS) após 5 min de ensaio, no qual a blenda SF:PVA apresentou maiores valores de absorção. A caracterização das membranas por FT-IR ATR e DRX mostrou que ocorreu uma transição de conformação aleatória e hélice \'alfa\' para folha \'beta\', para todas as membranas, indicando que a adição do PVA nas blendas promoveu transições silk I para silk II. Deslocamentos de modo vibracional de 1.637/cm (amida I) para 1.616/cm (amida I) com modo centrado em 1.512/cm (amida II) foram vistos em todas as blendas no FT-IR ATR, e difratogramas apresentaram picos característicos às estruturas silk I (2\'teta\' = 10,12º, 2\'teta\' = 12,2° e 2\'teta\' = 28,2º) e silk II (2\'teta\' = 20 - 21 °1). TGA e DSC mostraram uma interação entre as cadeias de RSF c PVA, pela presença de uma temperatura única ele transição vítrea (Tg) entre RSF e PVA. Imagens AFM das blendas mostraram a presença de estruturas nanofibrilares, em formato de ilhas compactas e ramos, confirmando a transição da fase amorfa de SF 2% para hélice \'alfa\' e folha \'beta\', com a adição do PVA.
Silk fibroin (SF) is a fibrous hydrophobic protein produced by silkworms (Bombyx mori L.), which production and storage occur into specialized glands previously fiber formation. Lately, regenerated silk fibroin (RSF) solutions have been used to produce different materials such as gels, membranes, films and sponges, for medical applications and drug delivery systems. In this study, the RSF with 0.25, 0.5 anel 1% PVA (synthetic and hydrophilic polymer) blends were characterized by rheological tests of the gels (SF:PVA), also membranes produced by casting process were characterized as well. Rheological tests showed moduli inversion with elastic to viscous behavior transition for SF 1 to 3%, between 230 anel 900% of strain (\'gama\'); a transition fram viscous to elastic behavior to SF:PVA 0.5 to 1% blends into frequency sweep tests was observed. With the temperature increment, all blends have kept their viscous anel elastic behavior until 49 - 51°C, and a liquid-gel transition occurred in the SF:PVA 0.5 and 1% blends, as well as all moduli have increased with the cooling stage of the samples. All membranes had the highest buffer absorption after 5 min of test, in which SF:PVA 0.5% blend presented high absorption values. FT-IR spectra and XRD diffractograms showed a transition from random and \'alfa\'-helix to \'beta\'-sheet, for all blends, indicating that PVA addition promotes silk I to silk II transition. Modal shifts were observed from 1.637/cm (amide I) to 1.616/cm (amide I) with a central mode in 1.512/cm (amide II) in all blends in the FT-IR ATR spectra. XRD diffractograms showed characteristic peaks of silk I structures (2\'teta\' = 10,12°, 2\'teta\' = 12,2° e 2\'teta\' = 28,2°) and silk II structures (2\'teta\' = 20 - 21 °1). TGA and DSC studies showed the possibility of interaction between SF and PVA chains by acquirement of mobility at once, at an intermediate temperature between SF anel PVA glass transition (Tg). AFM images exhibited different phases for all membranes, with the presence of nanofibers, wires, rods and branch islands, suggesting the formation of more organized structures, such as and \'alfa\'-helix and \'beta\'-sheet, with PVA addition.

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Ribeiro, Ana Carolina Prado 1981. "Análise das características clinicopatológicas de displasias fibrosas e fibromas ossificantes centrais envolvendo mandíbula e maxila = estudo colaborativo internacional." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288415.

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Orientador: Pablo Agustin Vargas
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
Made available in DSpace on 2018-08-18T23:49:50Z (GMT). No. of bitstreams: 1 Ribeiro_AnaCarolinaPrado_D.pdf: 3258651 bytes, checksum: 970c0be7e5e81418de0473e4d576d304 (MD5) Previous issue date: 2011
Resumo: A displasia fibrosa (DF) e o fibroma ossificante central (FOC) fazem parte de um grupo de lesões conhecido como fibro-ósseas benignas (LFOB) e afetam principalmente a maxila, a mandíbula e ossos da região craniofacial. Caracterizam-se pela substituição do tecido ósseo normal por uma matriz de tecido conjuntivo fibroso com níveis variados de material mineralizado. As DFs e os FOCs costumam apresentar características clínicas e histopatológicas similares, entretanto, possuem padrões distintos de progressão e comportamento biológico. Portanto é muito importante fazer a distinção diagnóstica entre estas lesões. Este trabalho teve como objetivos analisar e comparar as características demográficas, clínicas, imaginológicas e histopatológicas de pacientes diagnosticados com DFs e FOCs. Foi realizada uma análise retrospectiva internacional e multi-institucional que selecionou 68 casos de DF e 37 casos de FOC e permitiu o estudo de características clinicopatológicas. As DFs (n=41; 60,2%) e os FOCs (n=24; 64,9%) foram mais comuns em pacientes do gênero feminino na segunda e terceira década de vida. As DFs acometeram preferencialmente a maxila (n=38; 56%) e os FOCs a mandíbula (n=23; 62,2%). Com relação aos aspectos imaginológicos, as DFs apresentaram-se predominantemente como lesões radiopacas com limites mal definidos e os FOCs como lesões radiolúcidas bem delimitadas. Microscopicamente, foi possível evidenciar continuidade do osso lesional com a cortical óssea de revestimento nas DFs e, interessantemente, um fenômeno de separação entre as trabéculas ósseas lesionais e o estroma adjacente também foi evidente nas DFs. Nos FOCs, foi possível evidenciar a descontinuidade da lesão com a cortical óssea de revestimento externo e a presença de estruturas semelhante ao cemento. Em conclusão, o diagnóstico de DF e FOC deve ser realizado a partir da correlação das características clínicas, imaginológicas e histopatológicas. No entanto, foi possível observar algumas características peculiares em cada uma das lesões, o que poderá auxiliar o diagnóstico e consequentemente favorecer o tratamento dos pacientes acometidos por estas patologias ósseas
Abstract: Fibrous dysplasia (FD) and ossifying fibroma (OF) comprehend a group of benign fibro-osseous lesions (BFOL) which mainly affects the maxilla, mandible and craniofacial bones. They are characterized by the replacement of normal bone tissue by a matrix of fibrous connective tissue with varying degrees of mineralization. Both lesions frequently share clinical and microscopic features and the final diagnose require a combined analysis of clinical, radiologic and histological data. There might be significant cosmetic and functional impairment despite having a distinct pattern of progression and biological behavior, therefore, it is important to distinguish them from each other at the final diagnose. This research focused on the study and comparison of the demographic, clinical, imaging and microscopic aspects of patients with FD and OF, at the moment of the diagnostics. A retrospective multiinstitucional research was conducted in which there were 68 FD cases and 37 of OF. Characteristics such as gender, age and anatomic site of the tumor samples were obtained from the medical records. FDs (n=41; 60,2%) and OFs (n=24; 64,9%) were more frequently detected in female patients who were at the second or third decade of life. The maxilla was more prominently affected among the FD cases (n=38; 56%) contrasting to the prevalence of the mandible in the OF cases (n=23 62.2%). According to the radiographic aspects, FDs frequently presented as radiopaque lesions, with ill-defined limits, and OFs had well defined margins and were radiolucid. Microscopically, a continuity of the lesion with the bone cortical was evident in the FDs, as well as a separation phenomenon between the bone trabeculae and the surrounding connective tissue of the adjacent stroma. In OFs, the discontinuity of the lesion with the bone cortical was noticed, so were the presence of cement-like structures. In conclusion, the diagnose of FD and OF must be done based on the sum of the clinical, radiographic and microscopic features, although it was possible to observe a few peculiar characteristics in each one of them, which might serve as a diagnostic tool and therefore improve the treatment of the patients
Doutorado
Patologia
Doutor em Estomatopatologia

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Pinho, Rodrigo Finger de Carvalho. "Estudo retrospectivo entre o fibroma ossificante, displasia fibrosa, displasia cemento-ossificante e lesões centrais de células gigantes." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/23/23154/tde-15082018-094840/.

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As lesões ósseas são doenças raras, mas com um grande destaque, que afetam a região maxilofacial. Dentre elas podemos destacar as Lesões Centrais de Células Gigantes e as Lesões Fibro-Ósseas Benignas (Displasia Cemento-Ossificante, Fibroma Ossificante e Displasia Fibrosa). O presente estudo teve como objetivo descrever e analisar os dados encontrados nas fichas de encaminhamento clínico presentes no Serviço de Patologia Oral e Maxilofacial da Faculdade de Odontologia da Universidade de São Paulo. Foram avaliados 89.265 casos em um período que variou de 1950 até 2016, utilizando as categorias de gênero, idade, etnia, sintomatologia, hipótese diagnóstica e localização anatômica. Após as exclusões, os casos selecionados somavam 773 casos divididos em: 267 casos de Lesão Central de Células Gigantes, 231 casos de Displasia Cemento Ossificante, 142 casos de Fibroma Ossificante e 133 de Displasia Fibrosa. Os resultados do estudo estão de acordo com o que está descrito na literatura, exceto nos casos de Displasia Fibrosa que foi encontrado uma predileção maior sexo feminino do que o masculino, mesmo que a literatura expresse que não existe tal predileção. Já nos casos de Displasia Cemento-Ossificante, o presente estudo mostrou que a maior prevalência de idade é entre a 4ª e 5ª década de vida e não entre a 3ª e 4ª como encontrado na literatura. Os casos de Displasia Cemento-Ossificante, em relação à etnia dos pacientes, mostraram que a maioria dos pacientes encontrados pelos autores eram leucodermas e não melanodermas como relata a literatura. Os resultados mostraram que mesmo em um centro de referência como o Serviço de Patologia Oral da Faculdade de Odontologia da Universidade de São Paulo, as lesões ósseas são raras e alguns fatores como idade em pacientes com Displasia Fibrosa e Displasia Cemento-Ossificante e etnia em pacientes com Displasia Cemento-Ossificante não correspondem ao encontrado na literatura mundial.
Bone lesions are rare but important diseases that affect the maxillofacial region. Among them we can highlight the Central Giant Cells Lesion and the Benign Fibro-Osseous Lesions (Cemento-Osseous Dysplasia, Ossifying Fibroma and Fibrous Dysplasia). The objective of this study was to describe and analyze the data found in the clinical referral forms present at the Oral and Maxillofacial Pathology Service of the Faculty of Dentistry of the University of São Paulo. We evaluated 89.265 cases in a period ranging from 1950 to 2016, using the categories of gender, age, ethnicity, symptomatology, diagnostic hypothesis and anatomical location. After the exclusions, the selected cases totaled 773 cases divided into 267 cases of Central Giant Cell Lesion, 231 cases of Cemento-Osseous Dysplasia, 142 cases of Ossyfing Fibroma and 133 cases of Fibrous Dysplasia. The results of the study are in agreement with what is described in the literature, except in the cases of Fibrous Dysplasia that a predilection was found greater female than the male, even if the literature expresses that there is no such predilection. In the cases of Cemento-Osseous Dysplasia, the present study showed that the highest prevalence of age is between the 4th and 5th decade of life and not between the 3rd and 4th as found in the literature. The cases of Cemento-Osseous Dysplasia, in relation to the ethnicity of the patients, showed that the majority of the patients found by the authors were white and not black as reported in the literature. The results showed that even in a reference center such as the Oral Pathology Service of the Faculty of Dentistry of the University of São Paulo, bone lesions are rare and some factors such as age in patients with Fibrous Dysplasia and Cement-Ossificante Dysplasia and ethnicity in patients with Cement-Ossific Dysplasia do not correspond to that found in the world literature.

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Polak, Roberta. "Preparação, avaliação físico-química e biológica in vitro de pericárdio bovino conjugado com fibroína de seda/quitosana via liofilização e irradiação." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-28012011-111458/.

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Neste trabalho, a irradiação por feixe de elétrons foi estudada como uma ferramenta para a reticulação do tecido de pericárdio bovino (PB). A conjugação de quitosana e fibroína de seda no tecido de PB liofilizado também foi objeto de estudo deste trabalho. Para isto, amostras de PB foram liofilizadas e irradiadas em um acelerador de elétrons utilizando-se diferentes doses e taxas de dose. Essas amostras foram analisadas por calorimetria exploratória diferencial (DSC), análises termogravimétricas (TGA), espectroscopia Raman, teste de intumescimento, microscopia eletrônica de varredura (MEV), microscopia eletrônica de transmissão (MET), testes de tração e quanto sua biofuncionalidade. Após as análises foi possível concluir que a irradiação do tecido na ausência de oxigênio favorece a reticulação das fibras de colágeno, enquanto na presença de oxigênio observou-se preferencialmente a cisão das fibras de colágeno. Ambas as amostras apresentaram diminuição de suas propriedades mecânicas. Também pôde-se concluir que a irradiação tanto na ausência quanto na presença de oxigênio produz um novo biomaterial cuja adesão e proliferação de células endoteliais é favorecida ao longo do tecido. Na segunda etapa deste trabalho amostras de PB liofilizadas foram incorporadas em soluções de quitosana, fibroína de seda e suas misturas (1:3, 1:1, 3:1). Depois de modificadas, as amostras foram novamente liofilizadas e submetidas à irradiação. Estas amostras foram caracterizadas por espectroscopia Raman, e avaliadas quanto sua citotoxicidade, biofuncionalidade e potencial de calcificação. Após lavagens das amostras de biomaterial com solução aquosa (NaCl 0,9%), as mesmas não apresentaram toxicidade. O teste de biofuncionalidade mostrou que as amostras de PQSFI (todas as proporções) favoreceram a adesão e crescimento das células endoteliais. Todas as amostras induziram a calcificação, entretanto apresentaram uma relação Ca/P menor do que a da hidroxiapatita.
In this work, electron beam irradiation was studied as a crosslinker of bovine pericardium tissue (BP). The treatment of BP with chitosan and silk fibroin was also the goal of this study. Samples of BP were freeze-dried and irradiated in an electron beam accelerator using different doses and dose rates. Samples were analyzed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Raman spectroscopy, water uptake tests, scanning electron microscopy (SEM), transmission electron microscopy (TEM), tensile tests and evaluation as biofunctionality. After analysis, it was concluded that irradiation of the tissue in the absence of oxygen promotes crosslinking of collagen fibers. On the other hand, in the presence of oxygen the chain scission of the collagen fibers was observed, and both samples suffered a decrease in their mechanical properties. It was also concluded that irradiation, both in the absence or presence of oxygen, promotes the adhesion and proliferation of endothelial cells throughout the tissue. In the second part of this work, lyophilized BP were incorporated into chitosan, silk fibroin solutions and mixtures of chitosan/silk fibroin in the ratio of 1:3, 1:1, 3:1. Then, the samples were again lyophilized and submitted to irradiation. These samples were characterized by Raman spectroscopy, and tested for their cytotoxicity, biofunctionality, and calcification. After washing the biomaterial with aqueous solution (NaCl 0.9%), the samples did not show cytotoxicity. Biofunctionality test showed that PQSFI samples (all proportions) promoted the adhesion and growth of endothelial cells. All samples induced calcification, but they exhibited a Ca/P ratio lower than hydroxyapatite.

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Netto, Ana Carolina de Mesquita. "Análise molecular dos genes HRPT2 e CICLINA D1 na displasia fibrosa, no fibroma ossificante e no osteossarcoma dos maxilares." Universidade Federal de Minas Gerais, 2012. http://hdl.handle.net/1843/ZMRO-8XCJPR.

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Fibrous dysplasia (FD), ossifying fibroma (OF), and osteosarcoma (OS) are examples of bone-related lesions. Recent studies have already shown genetic alterations of the HRPT2 tumor suppressor gene in sporadic and syndromic OF. The present study first sought to raise the hypothesis of whether or not similar alterations would in fact represent one of the underlying genetic alterations of both FD and OS. This study investigated alterations of the HRPT2/ parafibromin at the DNA level (using the loss of heterozygosity analysis - LOH), at the mRNA level (through RT-PCR, direct sequencing, and qRT-PCR), and in proteins through immunohistochemistry(IHC) in a set of OF, FD, and OS cases. In vitro studies pointed toward the inhibition of cyclin D1 as a mechanism of HRPT2 to produce antiproliferative effects. Thus, cyclin D1 expression through qRT-PCR and IHC was also investigated. LOH at 1q25.3 was assessed by using 2 microsatellite markers: D1S384 and D1S461. The LOH of HRPT2 was found in 3 FD, 6 OF, and 2 OS cases. However, this did not prove to be associated with alterations in the mRNA transcription or protein expression of the gene. The HRPT2 mutation was found only in the OF (primary and recurrent lesion). This mutation commonly leads to the formation of a truncated protein; however, in this case, it caused no alteration in the transcription of the HRPT2 and cyclin D1 genes. In addition, this study found a positive correlation between the mRNA transcription of HRPT2 and cyclin D1, which was not observed between parafibromin and cyclin D1 protein immunostaining. In conclusion, this studys results emphasize that DNA alterations of the HRPT2 gene can be detected in OF as well as in FD and OS, but the mutation or LOH of this gene does not necessarily impact mRNA or protein expression.
A displasia fibrosa (DF), o fibroma ossificante (FO) e o osteossarcoma (OS) são considerados lesões ósseo-relacionadas que possuem uma etiopatogênese incerta. Recentemente foram descritas alterações genéticas no gene supressor de tumor HRPT2 em FO. O gene HRPT2 codifica uma proteína de 531 aminoácidos denominada parafibromina. Neste estudo, pela primeira vez, foi levantada a hipótese se alterações similares não poderiam participar da patogênese da DF e OS e se estas alterações estariam presentes em uma grande proporção dos FO. Em uma amostra de lesões ósseo-relacionadas foram investigadas alterações no gene HRPT2/parafibromina em nível de DNA (através da análise da perda de heterozigosidade LOH), do transcrito mRNA (através do RT-PCR, do sequenciamento direto e qPCR em tempo real) e da proteína (através de imunoistoquímica). A LOH no locus 1q25.3 foi investigada utilizando os marcadores microssatélites D1S384 e D1S461. Além disso, já foi apontado em estudos in vitro uma propriedade antiproliferativa da parafibromina por meio da inibição da ciclina D1. Investigamos nas lesões ósseo-relacionadas a expressão da ciclina D1 por qRT-PCR e imunoistoquímica. A LOH do gene HRPT2 pode ser encontrada em difentes lesões ósseas, como DF, FO e o OS, mas esta não está associada com alterações na transcrição do gene ou da expressão da proteína do gene. No entanto, a mutação no gene HRPT2 foi encontrada somente em um caso de FO (lesão primária e recidiva). Esta mutação encontrada gerou uma proteína truncada, não obstante este evento não teve impacto no nível de transcrição dos genes estudados (HRPT2 e Ciclina D1). Apesar de se ter observado correlação positiva entre a transcrição de mRNA de HRPT2 e ciclina D1, esta correlação não foi observada entre a expressão imunoistoquímica de parafibromina e ciclina D. Concluindo, os resultados deste trabalho apontam que alterações no gene HRPT2 podem ser detectadas tanto no FO quanto nas DF e OS, porém a mutação ou LOH deste gene não necessariamente tem um impacto sobre a transcrição de mRNA ou da expressão da proteína parafibromina no grupo de lesões estudadas

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Badra, Suzanna Bizarro. "Estudo do equilíbrio de fases em sistemas contendo polímeros naturais: fibroína de seda e alginato de sódio." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-08032019-112706/.

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Blendas poliméricas de biopolímeros, além de apresentarem uma melhora das propriedades do material, ainda possuem as vantagens de serem biocompatíveis, biodegradáveis e apresentar baixa toxicicidade, como no caso de blendas de alginato de sódio e fibroína de seda. Membranas confeccionadas a partir desta mistura apresentam grande potencial no desenvolvimento de curativos de alto desempenho, proporcionando condições ótimas de cicatrização. Entretanto, o processo de mistura destes biopolímeros é bastante complexo e resulta na separação de fases, processo que ainda não foi muito explorado. Este trabalho buscou explorar experimentalmente o comportamento do equilíbrio de fases dos sistemas aquosos contendo fibroína de seda e alginato de sódio em diversos valores de pH. Soluções aquosas de fibroína foram previamente preparadas por meio de processo de diálise, e soluções de alginato, por meio de dissolução direta em água. Ambas as soluções eram misturadas em concentrações em que se desejava avaliar o comportamento de fases. Após a separação de fases, a fase líquida sobrenadante era coletada, a fibroína quantificada via espectrofotometria e o alginato, via calcinação. Observou-se que a região monofásica do diagrama de fases é pequena, e a separação de uma segunda fase ocorre em concentrações baixas dos dois biopolímeros. A separação de fases pôde ser descrita como a precipitação da fibroína pela adição de alginato, e a solubilidade da fibroína pôde ser descrita por meio da equação de Cohn. As curvas de solubilidade obtidas não apresentaram diferenças significativas em função do pH. Medidas do potencial Zeta de soluções de alginato e fibroína em diversas faixas de pH não mostraram diferenças significativas quanto à carga superficial das moléculas, o que é compatível com a ausência de influência do pH no equilíbrio de fases.
Polymer blends formed by biopolymers may show an improvement of material properties (compared to the pure biopolymers), and present advantages such as biocompatibility, biodegradability and low toxicity. An interesting biopolymer blend is that formed by sodium alginate and silk fibroin. Membranes prepared with this mixture show great potential in the development of high-performance wound dressing, since it provides optimum healing conditions. However, the mixing process of these two biopolymers is complex and has not been extensively explored. In this work the phase equilibrium behavior of aqueous systems containing silk fibroin and sodium alginate was experimentally studied at different pH values. Fibroin aqueous solutions were previously prepared through dialysis, and alginate solutions were prepared by direct dissolution in water. Both solutions were mixed at the concentration range in which the phase behavior of the system was to be assessed. After phase separation, the supernatant liquid phase was separated, the fibroin was quantified through spectrophotometry. and the alginate was quantified through calcination. The single-phase region of the phase diagram is small, and the separation of a second phase occurs at low concentrations of both biopolymers. The phase separation could be described as the precipitation of fibroin due to the addition of alginate, and the solubility of fibroin was described by the Cohn equation. The solubility was not significantly affected by the pH. The Zeta potential of either alginate or fibroin, measured in solutions of different pH values, did not present any significant difference concerning the surface charges of these macromolecules. This finding agrees with the absence of pH influence upon the phase equilibrium.

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Ruiz, Marcelo Martinson. "Estudo retrospectivo das características clínico-demográficas e histopatológicas e avaliação da imunoexpressão da interleucina-6, osteocalcina, osteoprotegerina e RANKL na distinção entre a displasia fibrosa e o fibroma ossificante." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/23/23139/tde-07062017-153659/.

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As lesões fibro-ósseas da região maxilomandibular constituem um grupo heterogêneo de patologias que incluem lesões de desenvolvimento, reativas (displásicas) e neoplásicas, sendo que as duas principais entidades incluídas neste grupo são a displasia fibrosa e o fibroma ossificante. Devido a grande similaridade histológica entre estas patologias a avaliação das características clínicas e imaginológicas, juntamente com os aspectos histopatológicos, são o principal método de diagnóstico diferencial, porém devido a presença de diferentes níveis de maturidade destas patologias, em diversos casos os componentes histológicos assim como seu ordenamento são muito semelhantes. A busca por um processo de diagnóstico histológico mais fundamentado, hoje inexistente, é justificada pela diferença do curso clínico assim como pela eleição do tratamento entre a displasia fibrosa e o fibroma ossificante. Desta forma o propósito deste trabalho foi realizar uma análise retrospectiva descritiva das características clínico-demográficas e histopatológicas, e estabelecer um critério de diagnóstico diferencial que associe algumas características histopatológicas padronizadas juntamente com uma análise imunoistoquímica dos fatores de atividade de remodelação óssea destas lesões. Desta forma foram aplicados diferentes marcadores proteicos e moleculares em casos previamente diagnosticados de displasia fibrosa e fibroma ossificante, objetivando direcionar um critério de diagnóstico mais preciso. Nesse estudo retrospectivo foram avaliados 54 casos, sendo 30 casos de displasia fibrosa e 24 casos de fibroma ossificante, definidos após uma revisão nas análises das lâminas seguindo um padrão com algumas particularidades histomorfológicas para o diagnóstico diferencial. As características histológicas utilizadas para essa diferenciação, baseadas na revisão da literatura, foram: 1- limite entre a lesão e o tecido ósseo adjacente; 2- depósitos esféricos basofílicos (calcificações cementóides); 3- espaços negativos limítrofes entre o tecido ósseo e o tecido conjuntivo; 4- intensidade da celularidade do estroma e; 5- paralelismo das trabéculas ósseas lesionais. Após a reavaliação das lâminas seguindo a padronização de diferenciação com os cinco critérios histológicos mencionados anteriormente, foram reconsiderados os diagnósticos de 7 lâminas, ou seja 12,96% das amostras apresentaram alteração no diagnóstico anatomopatológico inicial. Posteriormente foram utilizados os seguintes imunomarcadores proteicos e moleculares do metabolismo ósseo em 9 lâminas de fibroma ossificante e em 7 lâminas de displasia fibrosa: interleucina 6 (IL-6), osteoprotegerina (OPG), osteocalcina (OCN) e o ligante do receptor do ativador do fator nuclear Kappa B (RANKL). A imunoexpressão destes marcadores foi observada nos seguintes locais: osteócitos, osteoblastos, osteoclastos e no estroma. Apenas a osteoprotegerina apresentou significância estatística nos osteócitos, osteoblastos e osteoclastos. A osteoprotegerina no estroma e os demais marcadores não apresentaram significância estatística em nenhum dos locais.
The fibro-osseous lesions of the maxillomandibular region constitute a heterogeneous group of pathologies that include developmental, reactive (dysplastic) and neoplastic lesions, and the two main entities included in this group are fibrous dysplasia and ossifying fibroma. Due to the great histological similarity between these pathologies the evaluation of the clinical and imaging characteristics, together with the histopathological aspects, are the main method of differential diagnosis, however due to the presence of different levels of maturity of these pathologies, in several cases the histological components as well as their arrangement are very similar. The search for a more substantiated histological diagnosis process, which does not exist today, is justified by the difference in the clinical course as well as by the choice of treatment between fibrous dysplasia and ossifying fibroma. Therefore, the purpose of this study was to perform a descriptive retrospective analysis of the clinical-demographic and histopathological characteristics and to establish a differential diagnosis criterion that associates some standard histopathological characteristics together with an immunohistochemical analysis of the bone remodeling activity factors of these lesions. In this way different molecular and protein markers were applied in previously diagnosed cases of fibrous dysplasia and ossifying fibroma, aiming at directing a more precise diagnosis criterion. In this retrospective study, 54 cases were evaluated, 30 cases of fibrous dysplasia and 24 cases of ossifying fibroma, defined after a review in the analysis of the slides following a pattern with some histomorphological peculiarities for the differential diagnosis. The histological characteristics used for this differentiation, based on the literature review, were: 1- border between the lesion and the adjacent bone tissue; 2- basophilic spherical deposits (cementoid calcifications); 3 - borderline negative spaces between the bone tissue and connective tissue; 4- intensity of stroma cellularity; 5- parallelism of lesionous trabeculae. After the reassessment of the slides following the standardization of differentiation with the five histological criteria mentioned above, the diagnoses of 7 slides were reconsidered, that is, 12.96% of the samples presented alterations in the initial anatomopathological diagnosis. Subsequently, the following protein and molecular biomarkers of bone metabolism were used on 9 ossifying fibrous slides and on 7 fibrous dysplasia slides: interleukin 6 (IL-6), osteoprotegerin (OPG), osteocalcin (OCN) and the activator receptor ligand Of nuclear factor Kappa B (RANKL). Immunoexpression of these markers was observed at the following sites: osteocytes, osteoblasts, osteoclasts and in the stroma. Only osteoprotegerin presented statistical significance in osteocytes, osteoblasts and osteoclasts. The osteoprotegerin in the stroma and the other markers did not present statistical significance in any of the sites.

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Wallet, Brett. "Structural investigation of silk fibroin-based membranes." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51907.

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Silk fibroin has created a surge of interest for use as organic material due to its optical transparency, biocompatibility, biodegradability, and excellent physical properties. However, the implementation of silk films and structures into biomedical and sensing devices has been relatively low due to a lack of understanding of the mechanisms involved in such implementation. Increasing need for multifunctional high-performance organic materials has caused an emphasis on the ability of researchers to spatiotemporally pattern and control the structure and consequently functional properties of materials. Silk fibroin displays high potential for use as a controllable biomaterial that can be formed into a myriad of different structures for various applications. By implementation of an aqueous silk solution approach combining various fabrication techniques, several different pristine-silk and silk-composite membranes have been developed to investigate the importance of internal structuring. Different methods of investigation include: 1) incorporation of reinforcing nanoparticles within the silk matrix; 2) neutron reflectivity measurements of ultrathin silk films; 3) film patterning with nanoscale features followed by boundary organized surface mineralization of inorganic nanoparticles. The ultimate goal will be to provide fundamental data assisting in an increased knowledge of silk fibroin-based membranes and the effect of secondary structures on properties of interest.

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Lima, Paulo Autran Leite. "Preparação, caracterização e avaliação in vitro de compósitos baseados em quitosana, fibroína e hidroxiapatita para a engenharia tecidual óssea." Universidade Federal de Sergipe, 2012. https://ri.ufs.br/handle/riufs/3480.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Hybrid composites with chitosan (CHI), fibroin (SF) and hydroxyapatite (HA) are biocompatible and attractive for bone engineering applications. The objective of this work was to prepare, to characterize and to evaluate in vitro cells behavior in contact with CHI, CHI/SF and CHI/SF/HA scaffolds. The biomaterials were produced from a CHI, CHI/SF, CHI/SF/HA solution in acetic acid and, after the production process, they were submitted the in vitro tests with STRO+1A, MC3T3-E1 and SaOS-2 cells for 07, 14 and 21 days. The scaffolds were characterized by X-ray diffraction, attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy and energy dispersive spectroscopy. In addition, tests of porosity, pore size and contact angle were performed. Cell viability and activity were assessed by MTT reduction and alkaline phosphate activity detection. It was possible to prepare scaffolds 3D based on chitosan, fibroin and hydroxyapatite and the interaction between this materials were observed by physicochemical characterization. The composites were considered non-toxic and they were capable to promote cell adhesion, proliferation and differentiation. Additionally, they may be used in the therapy of bone defect repair.
Compósitos híbridos de quitosana (CHI), fibroína (SF) e hidroxiapatita (HA) são biocompatíveis e atrativos para aplicações na engenharia tecidual óssea. O objetivo desse trabalho foi preparar, caracterizar e avaliar o comportamento in vitro de compósitos 3D de CHI, CHI/SF, CHI/SF/HA. Os biomateriais foram produzidos a partir de uma solução de CHI, CHI/SF e CHI/SF/HA em ácido acético e após a realização dos processos de produção foram submetidos a testes in vitro com células STRO+1A, MC3T3-E1 e SaOS-2 por 07, 14 e 21 dias. Os arcabouços foram caracterizados por difração de raios-X, espectroscopia no infravermelho com transformada de Fourier com refletância total atenuada, análise termogravimétrica, calorimetria exploratória diferencial, microscopia eletrônica de varredura, espectroscopia de energia dispersiva, e submetidos a testes para verificação da porosidade, tamanho de poro e ângulo de contato. A viabilidade e a atividade celular foram avaliadas por redução de MTT e pela detecção da atividade de fosfatase alcalina. Foi possível preparar arcabouço 3D com matriz baseada em quitosana, fibroína e hidroxiapatita e houve interação entre esses materiais, sendo constatado através da caracterização físico-química. Ambos os compósitos foram considerados atóxicos e capazes de promover adesão, proliferação e diferenciação celular, podendo ser utilizados na terapia do reparo de defeito ósseo.

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Lima, Andreia Filipa de Alvanéo. "Displasia fibrosa monostótica." Master's thesis, [s.n.], 2012. http://hdl.handle.net/10284/3434.

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Trabalho apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
A displasia fibrosa monostótica é uma alteração óssea benigna, caraterizada pela substituição de tecido ósseo normal por tecido fibroso imaturo. Esta patologia manifesta-se preferencialmente em crianças e adolescentes durante o período de crescimento. Ainda, em contexto epidemiológico, há uma predileção pelo sexo feminino. A forma monostótica envolve um só osso e na maior parte dos casos a maxila é o osso acometido. Os exames radiológicos (com aspeto de “vidro fosco”), as caraterísticas clínicas (assimetria facial), dados neurorradiológicos (por exemplo, transtornos visuais), caraterísticas histopatológicas (lembra a escrita chinesa) e as caraterísticas bioquímicas (aumento da fosfatase alcalina) são de extrema importância para um bom diagnóstico da patologia e para a seleção de um correto tratamento. O tratamento de eleição é o tratamento conservador, quando não há comprometimento estético ou funcional. Geralmente, a cirurgia só deve ser efetuada quando cessa o crescimento. No caso de se optar pela cirurgia, a tomografia é o método de diagnóstico de eleição para avaliar a expansão tumoral, ajudando no planeamento cirúrgico. A displasia fibrosa monostótica poderá em alguns casos ter recidiva. No presente trabalho, são analisados casos clínicos descritos na literatura, onde se observa qual o meio de diagnóstico, manifestações clínicas e a terapêutica implementada, permitindo um enquadramento científico atual, que auxilia a compreensão da displasia fibrosa num contexto clínico. The monostotic fibrous dysplasia is a benign bone change, characterized by replacement of normal bone by immature fibrous tissue. This condition manifests itself mainly in children and adolescents during the growth period. Still, in an epidemiological context, there is a predilection for females. The monostotic form involves a single bone, and in most cases the jaw bone is involved. Radiological examinations (with the aspect of "ground glass"), the clinical features (facial asymmetry), neuroradiological data (for example, visual disturbances), histopathological features (remember the chinese script) and biochemical features (elevated alkaline phosphatase) are extremely important for a proper diagnosis of the disease and for selecting the correct treatment. The treatment of choice is conservative treatment, when there is no aesthetic or functional impairment. Generally, surgery should be performed only when growth ceases. In case to choose for surgery, tomography is the diagnostic method of choice to evaluate tumor expansion, assisting in surgical planning. The monostotic fibrous dysplasia may in some cases have recurrence. In this work, were analyzed the clinical cases described in the literature, where it is observed that the means of diagnosis, clinical manifestations and treatment implemented, are important in order to allow a current scientific framework, which helps the understanding of fibrous dysplasia in a clinical setting.

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Santos, Pedro Paulo de Andrade. "Express?o imuno-histoqu?mica da triptase em mast?citos nos fibromas de c?lulas gigantes e hiperplasias fibrosas de mucosa oral." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17103.

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Made available in DSpace on 2014-12-17T15:32:16Z (GMT). No. of bitstreams: 1 PedroPAS.pdf: 6126862 bytes, checksum: 3ae3ec2483d9e09d3a05fcd73782e862 (MD5) Previous issue date: 2008-02-27
Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
The giant cell fibroma is a benign neoplasm characterized by the presence of mono, bi or multinucleate cells, which can have a connection to the presence of mast cells. This research aims to analyze, descriptively and comparatively, the immunohystochemistry expression of the tryptase in mast cells of the giant cell f ibroma, f ibrous hyperplasia and samples of the normal oral mucosa. Thirty cases of giant cell fibroma, ten cases of fibrous hyperplasia and ten cases of normal oral mucosa were selected for the analysis of the immunohistochemistry expression, determination of the number of present mast cells, as well as their location and shape. It could be stated that there was a statistically signif icant difference (p<0,001) in relation to the quantity of mast cells among other samples analyzed where the giant cell f ibroma presented lesser quantity of mast cell and the hyperplasia showed higher concentration of this cellular type. Although the oral mucosa has presented a higher quantity of mast cells when compared to the giant cells fibroma, these were found in usual locations in the connective tissue in normal tissues. There could be noticed a statistically significant difference in relation to the number of non-granulated mast cells (p<0,001). On the areas of fibrosis, we could observe a statistically signif icant difference (p<0,006) among the samples. In relation to the present mast cells in perivascular location, no statistically signif icant difference was found. On the morphological analysis there was a predominance of oval mast cells. It was concluded that despite of the fact there was a lesser quantity of mast cells present in cases of giant cell f ibroma, they appeared to have a stronger relation to the present giant fibroblasts in this lesions, around 59,62%, being also evidenced a strong relation between these cells and the fibrosis areas in both cases of giant cell f ibroma and f ibrous hyperplasias and samples of normal oral mucosa, used as control group in our study, confirming, this way, the role of the mast cells as fibrinogenous inductor
O fibroma de c?lulas gigantes constitui-se de uma neoplasia benigna, caracterizada pela presen?a de c?lulas gigantes, mono, bi ou multinucleadas, c?lulas estas que podem guardar rela??o com a presen?a de mast?citos. O prop?sito desta pesquisa consistiu em analisar descritiva e comparativamente a express?o imuno-histoqu?mica da triptase em mast?citos de fibroma de c?lulas gigantes, hiperplasia fibrosa e esp?cimes de mucosa oral normal. Foram selecionados 30 casos de fibroma de c?lulas gigantes, 10 casos de hiperplasia fibrosa e 10 casos de mucosa oral normal, para a an?lise da express?o imuno-histoqu?mica, determina??o do n?mero de mast?citos presentes, bem como a sua forma e localiza??o. Constatou-se diferen?a estatisticamente significativa (p<0,001) em rela??o a quantidade de mast?citos entre os esp?cimes analisados, onde o fibroma de c?lulas gigantes apresentou a menor quantidade de mast?citos e a hiperplasia exibiu a maior concentra??o deste tipo celular. Embora a mucosa oral tenha apresentado uma maior quantidade de mast?citos quando comparado com os casos de f ibroma de c?lulas gigantes, estes se encontravam em localiza??es usuais no tecido conjuntivo em tecidos normais. Verif icou-se, diferen?a estatisticamente significativa, no que diz respeito ao n?mero de mast?citos n?o degranulados (p<0,001). Nas ?reas de fibrose, observamos diferen?a estatisticamente signif icativa (p<0,006) entre os esp?cimes. Com rela??o aos mast?citos presentes em localiza??o perivascular n?o se observou diferen?a estatisticamente significativa. Na an?lise morfol?gica verif icou-se uma predomin?ncia de mast?citos ovais. Concluiu-se que embora uma menor quantidade de mast?citos estivesse presente nos casos de fibroma de c?lulas gigantes, estes exibiam maior rela??o com os fibroblastos gigantes presentes nestas les?es em torno de 59,62%, sendo evidenciada tamb?m uma forte rela??o entre estas c?lulas e ?reas de fibrose tanto nos casos de fibroma de c?lulas gigantes como de hiperplasias fibrosas e esp?cimes de mucosa oral normal, utilizados como controle em nosso estudo, confirmando desta forma, o papel dos mast?citos como indutor fibrinog?nico

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26

Hızal, Bayçın Deniz Bayraktar Oğuz. "Adsorption of olive leaf antioxidants on silk fibroin/." [s.l.]: [s.n.], 2006. http://library.iyte.edu.tr/tezlerengelli/master/kimyamuh/T000551.pdf.

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27

McCool, Jennifer. "Silk Fibroin-Based Scaffolds for Tissue Engineering Applications." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/2528.

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This study focused on the comparison of the electrospun silk scaffolds to the electrospun silk fibroin gel scaffolds. Moreover, this study examined the differences in cross-linking effects of genipin and methanol as well as solvents on the mechanical properties and cell compatibility of the scaffolds. Silk scaffolds were electrospun from an aqueous solution or 1,1,1,3,3-hexafluoro-2-propanol (HFIP) without genipin, immediately after 8 % (wt) genipin was added to the solution, and 18 hours after genipin blended with the solution. Uniaxial tensile testing determined that the silk scaffolds electrospun from water exhibit a higher modulus and peak stress than that of the silk scaffolds electrospun from HFIP. In vitro cell culture was conducted to determine the cell compatibility of the various silk fibroin-based scaffolds. 4'-6-Diamidino-2-phenylindole (DAPI) staining and histology suggest that genipin may enhance cell compatibility, and that neither ethanol nor methanol inhibit cell interactions.

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Hodgkinson, Tom. "Silk fibroin biomaterials for skin tissue engineering applications." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/silk-fibroin-biomaterials-for-skin-tissue-engineering-applications(75958c4c-dacf-466f-ae6f-e8c9bb7c20b8).html.

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The limited reparative capacity of the skin and the inadequacy of conventional treatments have necessitated the development of tissue engineered skin substitutes. Several substitutes, including Integra Dermal Regeneration Template, are finding increasingly widespread application in the treatment of acute and chronic wounds. To date, these substitutes are unable to fully recreate the functionality and aesthetics of skin prior to injury. This thesis applied an integrated approach combining solution preparation, material fabrication control and biological testing to investigate electrospun silk fibroin (SF) nano-microfibrous scaffolds as potential biomimetic skin substitutes. Further to this, the improvement of the existing Integra scaffold through the incorporation of hyaluronan (HA) was assessed. Through rheological analysis of regenerated SF solutions under shear and extensional deformation a concentration regime transition at 20 wt% SF was identified. Solutions with relaxation times under 0.001 seconds were found to be unsuitable for electrospinning. The incorporation of poly(ethylene oxide) (PEO) was found to significantly increase solution relaxation times and extensional viscosity, making them much more suitable for electrospinning. Solution viscoelastic properties were shown to directly influence electrospun fibre morphology, with increases in viscosity resulting in increases in fibre diameter under stable spinning conditions. The effects of electrospinning parameters on electrospun fibre morphologies were investigated using SF-PEO blended solutions. Increased electrical field, spinneret height and decreased flow rate were found to decrease fibre diameter. In vitro assessment of the attachment, spreading, proliferation, viability and gene expression of primary human dermal fibroblasts (PHDFs) and bone marrow-derived mesenchymal stem cells (BM-MSCs) was conducted. Both PHDFs and BM-MSCs attached and proliferated with greater rapidity on fibres of the smallest diameters (~250-300 nm) with proliferation decreasing as fibre size increased until fibre diameters reached ~1200 nm. Cells were observed to be spread, with multiple attachments between fibres in scaffolds composed of ~250-300 nm diameter fibres. Cells aligned themselves to single fibres in scaffolds composed of fibres greater than 1 micrometre. HA supplementation to Integra resulted in increased proliferation, viability and migration of PHDFs. In ex vivo cutaneous wound healing models, the invasion of Integra was enhanced when scaffolds were supplemented with HA, with increased matrix deposition observed. Optimal supplementation concentrations for in vitro and ex vivo increases in cell proliferation and migration were at 1.5 – 2 mg ml-1 HA. SF electrospun scaffolds facilitated epithelial migration in ex vivo artificial wounds, with the migratory epidermis more closely resembling the structures observed in vivo. Additional preliminary investigations into the efficacy of a paste-form of Integra, Integra Flowable Wound Matrix (IFWM) were performed ex vivo, with cell invasion comparable to the conventional scaffold format. The potential for the incorporation of viable PHDFs and BM-MSCs was also investigated and keratinocyte migration was enhanced in these scaffolds. The results in this thesis provide valuable optimisation information on the development of SF electrospun scaffolds for skin engineering. Additionally, the supplementation of Integra with HA may provide a simple and effective way to enhance the performance of the scaffold in vivo.

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Kambe, Yusuke. "Molecular Design of Silk Fibroin for Functional Scaffolds." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/174922.

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Özgarip, Yarkın Bayraktar Oğuz. "Application of Silk Fibroin In Controlled-Release of Theophylline/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/kimyamuh/T000433.pdf.

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Ornell, Kimberly J. "Engineering silk fibroin scaffolds to model hypoxia in neuroblastoma." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-dissertations/591.

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Development of novel oncology therapeutics is limited by a lack of accurate pre-clinical models for testing, specifically the inability of traditional 2D culture to accurately mimic in vivo tumors. Neuroblastoma (NB) is a heterogeneous tumor, that in high-risk patients exhibits a 5-year event free survival rate of less than 50%. As such, there is a clinical need for development of novel systems that can mimic the tumor microenvironment and allow for increased understanding of critical pathways as well as be used for preclinical therapeutic testing. In this thesis, lyophilized silk fibroin scaffolds were used to develop 3D neuroblastoma models (scaffolded NB) using multiple neuroblastoma cell lines. Cells grown on scaffolds in low (1%) and ambient (21%) oxygen were compared to traditional 2D (monolayer) cell culture using oxygen-controlled incubators. We hypothesized that scaffolded growth would promote changes in gene expression, cytokine secretion, and therapeutic efficacy both dependent and independent of hypoxia. Monolayer culturing in low oxygen exhibited increased expression of hypoxia related genes such as VEGF, CAIX, and GLUT1, while scaffolded NB exhibited increased expression of hypoxia related genes under both low and ambient oxygen conditions. Pimonidazole staining (hypoxia marker) confirmed the presence of hypoxic regions in the scaffolded NB. Cytokine secretion in monolayer and scaffolded NB suggested differential secretion of cytokines due to both oxygen concentrations (e.g. VEGF, CCL3, uPAR) and 3D culture (e.g. IL-8, GM-CSF, ITAC). Additionally, treatment with etoposide, a standard chemotherapeutic, demonstrated a reduced response in scaffolded culture as compared to monolayer culture regardless of oxygen concentration. However, use of a hypoxia activated therapeutic, tirapazamine exhibited response in low oxygen monolayer culture as well as scaffolded culture in both low and ambient oxygen. To further expand this model into a single culture system capable of generating cell driven oxygen gradients, a stacked culture system was developed. NB scaffolds were stacked using a holder designed based on COMSOL modeling of oxygen tension in the medium. Post-culture, the scaffolds can be separated for analysis on a layer-by-layer basis. Analysis of scaffolds demonstrated a decrease in dsDNA and an increase in hypoxia related genes (VEGF, CAIX, and GLUT1) at the interior of the stack, comparable to that of the scaffolded low oxygen culture. Scaffolds on the periphery of the stack retained gene expression levels similar to that of scaffolded ambient oxygen culture. COMSOL modeling of stacks suggests oxygen gradients present throughout the tumor model similar to that of an in vivo tumor. Gradients of oxygen were confirmed through positive pimonidazole staining. In summary, we developed a system capable of altering critical oxygen-dependent and independent pathways through controlled oxygen levels and 3D culturing. Further, we enhanced this system through the design of a culture system capable of controlling cell driven hypoxic microenvironments to mimic that of an in vivo tumor. This system has the potential to be applied to multiple cancer types, allowing for understanding of key pathway changes and better development of therapeutics.

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Raggio, Rosasilvia. "Therapeutic silk fibroin-based systems for tissue engineering applications." Doctoral thesis, Università degli studi di Trento, 2019. http://hdl.handle.net/11572/243264.

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Tissue engineering (TE) is an interdisciplinary field, in continuous evolution, that possesses as main goal the creation of efficient systems for tissues and organs healing and regeneration. For bone, TE strategies are typically based on the combined use of scaffolds, cells, and bioactive molecules. Different materials were successfully studied and proposed for the fabrication of scaffolds. Among them, silk fibroin (SF) was evaluated as particularly promising for different TE applications, especially for bone tissue regeneration. Silk fibroin, a natural protein forming the structural core of silk filaments, holds biocompatibility, mechanical properties and biodegradation rate suitable for applications in bone regeneration. However, in the past, SF has shown some limitations, especially in terms of bioactivity and effective differentiating ability of hMSCs in regenerating bone tissue. In this work, we wanted to demonstrate that SF, properly processed, chemically modified, and conjugated with selected bioactive species, can be used to prepare different systems: a functionalised scaffold; a bioresorbable material with mineralization ability; an implantable immunomodulatory material. The experimental activities performed and the deep investigation of the properties of the SF-based systems prepared, led to promising results, indicating that SF could be a flexible and powerful platform for the realization of different therapeutic tools. For some of the SF-based systems described in this dissertation, further studies are needed to assess the biological activity of the materials prepared.

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Carlson, Kimberly Ann Trabbic. "Control of fibroin conformation : toward the development of a biomimetic spinning process for silk fibers /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/8099.

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Barbosa, Lígia Flávia da Silva. "Epidemiological factors associated with uterine fibroids." Master's thesis, Universidade da Beira Interior, 2012. http://hdl.handle.net/10400.6/1066.

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Introduction: The uterine fibroids are the most common benign neoplasm in the female genital tract. However, the prevalence of this disease in the general population is unknown, which justifies this investigation. Objective: To evaluate epidemiological factors associated with uterine myomas, in a setting of a private medical clinic. Methodology: It is presented as a cross-sectional research, drafted with a descriptive and an analytical component. To collect data a routine demographic computerized file was kept for every patient and a pelvic transvaginal or transrectal ultrasonography was performed. We retrieved from each patient their age at the time of consultation, weight, height, age of menarche, number of pregnancies, pregnancy outcome, marital status, level of education, menstrual cycle and contraceptive method used. Through the ultrasound examination, we recorded the presence of uterine myomas, their number and the largest dimension of the biggest myoma. Results: From the total women studied by ultrasonography (n = 624), uterine myomas were documented in 161 (25,8%) cases. Single myomas were presented in 49,7% (n = 80) and the majority of women had small fibroids, between 10 mm to 19 mm (41,6%, n = 67). Ages between 40 and 59 years, married marital status, overweight, menopause, previous pregnancy and delivery and complaints of menorrhagia were associated with a higher risk for uterine fibroids. The use of combined hormonal contraceptives was found to be a protective factor. Since these variables, after conducting a multivariate analysis, were all age dependent, we can suggest that aging is the only factor associated with the presence of uterine fibroids. Menorrhagia, metrorrhagia and pelvic pain were associated with a higher risk for multiple uterine fibroids. The use of combined hormonal contraceptives was associated with a higher risk for single fibroids. Ages between 40 and 59 years and a history of pregnancy and delivery were associated with a smaller dimension of the leiomyomas. Conclusion: Uterine myoma is a very common pathology among the female population. In our study, the only risk factor related with uterine fibroids was aging. Pregnacy and delivery seem to be associated with myomas of a smaller dimension. Single myoma is more common in patients using combined hormonal contraception.

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Vera, Sánchez Mª del Mar. "Efectos de films de fibroína de seda/óxido de grafeno vs fibroína de seda/óxido de grafeno reducido sobre células madre humanas de ligamento periodontal." Doctoral thesis, Universidad de Murcia, 2016. http://hdl.handle.net/10803/362097.

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OBJETIVOS El objetivo general de esta tesis es búsqueda de un biomaterial híbrido basado en grafeno y fibroína en una adecuada proporción de ambos, sobre el que las hPDLSCs muestren buenos resultados de adhesión, viabilidad, proliferación y/o diferenciación hacia diversos tipos celulares. Para alcanzarlo, se establecieron los siguientes objetivos específicos: • Objetivo 1: Elaboración y caracterización de films compuestos por grafeno y fibroína con distintas configuraciones y composiciones, con el fin de optimizar sus propiedades y potenciales aplicaciones en ingeniería de tejidos. • Objetivo 2: Evaluación in vitro de la morfología, proliferación, viabilidad y perfil mesenquimal de las hPDLSCs sobre los films elaborados, como puntos fundamentales en la optimización de este biomaterial híbrido. • Objetivo 3: Estudio de la capacidad inductora de diferenciación hacia osteoblastos, condroblastos o cementoblastos de los distintos materiales analizados en cultivos de hPDLSCs. METODOLOGÍA Las células madre de ligamento periodontal (hPDLSCs) se obtuvieron mediante la realización de cultivos primarios a partir de ligamento periodontal humano. Se realizaron distintas combinaciones de fibroína de seda y óxido de grafeno en forma de films, preparando una versión reducida de las misma configuraciones con ácido ascórbico. El análisis de la topografía de los materiales y la morfología celular se realizó mediante microscopía electrónica de barrido. La proliferación celular se estudió empleando el ensayo MTT. Mediante citometría de flujo se analizaron marcadores de superficie de células madre mesenquimales y viabilidad celular. Para el ensayo de expresión génica se realizó qPCR de genes codificantes para factores de transcripción específicos de osteo/condroblastos (RUNX2, SOX9 y SP7/OSX), proteínas osteoblásticas (BMP2, ALP, COL1A1 y BGLAP) y genes relacinados con cemento (PTPLA/CAP y CEMP1). CONCLUSIONES 1. La forma en que se disponen y mezclan SF y GO en la elaboración de los biomateriales como scaffolds 2D condiciona la topografía de los films. Esto ha dado como resultado la obtención de superficies con distinto grado de rugosidad, habiéndose observado desde superficies prácticamente lisas hasta superficies con características similares a un scaffold 3D. 2. En la mayoría de los films se observa la morfología fusiforme típica que muestran las hPDLSCs en cultivo de mantenimiento. Esta morfología se ve afectada al crecer en contacto directo con una superficie de fibroína pura, perdiendo la silueta fusiforme que sí se observa en el resto de configuraciones. 3. Tras 10 días en cultivo, la mayor tasa de proliferación de las hPDLSCs se alcanza, indistintamente, sobre los films de GO puro y la mezcla rGO:rSF(1:3). Sin embargo, sobre los films híbridos se observa la tendencia de una mayor proliferación en las formas reducidas que en las oxidadas. 4. Todos los films elaborados han resultados altamente biocompatibles en cultivos con hPDLSCs, obteniendo en todos los casos una viabilidad superior al 95% después de 10 días en cultivo. 5. Las hPDLSCs cultivadas durante 10 días muestran mayoritariamente una desregulación significativa de la expresión de marcadores mesenquimales (CD73, CD90 y CD105), principalmente cuando los materiales contenían rGO en su composición, lo que sugiere que se encuentren en un proceso de diferenciación. 6. El perfil de expresión génica de las hPDLSCs y la observación de depósitos de calcio tras su cultivo durante 10 días en el medio de inducción osteogénico Osteodiff®, indican que las hPDLSCs tienen plasticidad fenotípica y capacidad para diferenciarse a cementoblastos o a osteoblastos funcionales. 7. Se han hallado dos films sobre los que se obtiene una proliferación moderada, la configuración pura de rGO y la bicapa rGO/rSF, capaces de inducir, tras 10 días en cultivo, la diferenciación de hPDLSCs hacia células cementoblásticas sin la necesidad de añadir ninguna molécula inductora de este tipo de diferenciación. 8. De entre las configuraciones estudiadas, la bicapa rGO/rSF sería el film de elección (para continuar la línea de investigación de aplicaciones eventuales en terapia celular periodontal) al hallar un equilibrio entre consistencia del biomaterial, morfología, proliferación, viabilidad, perfil mesenquimal y capacidad diferenciadora de las hPDLSCs.
OBJECTIVES The aim of the present thesis is searching and hybrid biomaterial based on graphene and fibroin in an appropiate amount, where hPDLSCs show suitable results of adhesión, viability, proliferation and/or differentiation. • Objective 1: Manufacturing and characterization of films made of graphene and fibroin with different configurations to optimize their properties and potencial applications in tissue engineering. • Objective 2: In vitro evaluation of morphology, proliferation, viability and mesenchimal profile of hPDLSCs on every manufactured film. • Objective 3: To study the differentiting capacity to osteoblast, chondroblast or cementobblast-like cells of the different films in culture cell of hPDLSCs. METHODS Human periodontal ligament stem cells were obtained from human periodontal ligament primary cultures. Different configurations of silk fibroin and graphene oxide were manufactured as films, also in a reduced form with ascorbic acid treatment. Films topography and cell morphology were analyzed by scannig electronic micrsocopy. MTT assay was employed proliferation study. Flow citometry was used to analize expression of mesenchymal stem cell surface markers and celular viability. qPCR were run for gene expression analysis; different clusters of genes coding for osteo/chondroblast specific transcription factors (RUNX2, SOX9 and SP7/OSX), osteoblast-related proteins (BMP2, ALP, COL1A1 and BGLAP) as well as cementum-related genes (PTPLA/CAP and CEMP1) were assayed. CONCLUSIONS Graphene-fibroin-based biomaterials provide a new type of biocompatible scaffolds for stem cells. In graphene-fibroin composites, graphene supplies differentiating capacity, whereas SF cause no inflammatory response after their implantation, also providing to GO a better handling and 3D characteristics. Generally, reduced configurations gave better results in proliferation and gene expression, being these configurations the optimal in order to perform future in vivo experiments. In addition, the extracellular matrix resulting from our osteo/cementoblast-like cells may be more physiologically synthesized and mineralized than those from hydroxyapatite-derived substrates. hPDLSCs proliferation rate was consistently improved in certain combinations containing low amounts of graphene and a high fibroin dose. Remarkably, bilayer composites with graphene on the contact surface with cells promoted a moderate proliferation, and favoured a cementoblast differentiation of hPDLSCs in the absence of any growth factors.

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Uebersax, Lorenz. "Silk fibroin scaffolding for growth factor delivery in tissue repair." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17551.

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Marin, Michael. "Tuning and Optimization of Silk Fibroin Gels for Biomedical Applications." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3411.

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Biocompatible and biodegradable porous materials based on silk fibroin (SF), a natural protein derived from the Bombyx mori silkworm, are being extensively investigated for use in biomedical applications including mammalian cell bioprocessing, tissue engineering, and drug delivery applications. In this work, low-pressure, gaseous CO2 is used as an acidifying agent to fabricate SF hydrogels. This low-pressure CO2 acidification method is compared to an acidification method using high-pressure CO2 to demonstrate the effect of CO2 mass transfer and pressure on SF sol-gel kinetics. The effect of SF molecular weight on the sol-gel kinetics is determined using the low-pressure CO2 method. The results from these studies demonstrate that low-pressure CO2 processing proves to be a facile method for synthesizing 3D SF hydrogels. We also determined the effect of SF solution concentration on the morphology and textural properties of SF aerogels. Changing the solution concentration from 2 wt% to 6 wt% yielded a higher surface area (260 to 308 m2/g) and different macro structure, but similar mesopore pore volume and size, and micro structure. Furthermore, we determined the effect of drying method on the morphology and textural properties of SF hydrogels gelled via CO2 acidification. Drying with supercritical carbon dioxide (scCO2) yielded an aerogel surface area five times larger than aerogels that were freeze dried. Moreover, a freeze dried hydrogel initially frozen at -20 °C had pores approximately 10 µm larger than a hydrogel initially frozen at -196 °C. The results presented here also demonstrate the potential of SF aerogels as drug delivery devices for the extended release of ibuprofen, a model drug compound. SF aerogels are loaded with ~21 wt% of ibuprofen using scCO2 at 40 °C and 100 bar. Differential scanning calorimetry of the ibuprofen-loaded SF aerogels indicates that the ibuprofen is amorphous. Scanning electron microscopy and nitrogen adsorption/desorption analysis are used to investigate the morphology and textural properties. Phosphate buffer solution (PBS) soaking studies at 37 °C and pH 7.4 reveal that the SF aerogels do not swell or degrade for up to six hours. In vitro ibuprofen release in PBS at 37 °C and pH 7.4 occurs over a six-hour period when the ibuprofen is loaded in SF aerogel discs with an aspect ratio of ~1.65 (diameter/thickness), whereas the dissolution of the same amount of pure ibuprofen occurs in 15 minutes. Furthermore, the release of ibuprofen from these SF aerogel discs are modeled using the Fu model which indicates that ibuprofen release follows Fickian diffusion for the first 65 wt% of ibuprofen release, and non-Fickian diffusion for the next 25 wt% of ibuprofen release. We also showed that SF aerogel scaffolds support in vitro human foreskin fibroblast cell attachment, proliferation, propagation, and cell seeding of different densities (10x103, 30x103, and 60x103). In summary, we created and characterized a tunable 3D SF aerogel scaffold with potential for applications in drug delivery and tissue engineering applications.

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Quinn, Stephen. "Uterine fibroids : response to novel treatment modalities." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/24737.

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Magnetic resonance-guided focused ultrasound (MRgFUS) is a non-invasive, thermal ablation treatment for uterine fibroids. There is currently limited data regarding the long-term efficacy of this method and the effect of this treatment on circulating cytokine and growth factors. In this thesis I have: 1. Presented the most accurate method of measuring fibroid volumes, and propose a new classification system for describing fibroid uteri. 2. Reviewed the characteristics of a cohort of uterine fibroid subjects and perform a longitudinal analysis of MRgFUS results. 3. Assessed the fibroid volume treated, pain scores and cytokine levels and growth factor levels following MRgFUS and UAE. Results The Parallel Plannimetric method is an accurate and reliable method of measuring uterine, fibroid and non-perfused volumes. Classifying fibroid uteri by numbers of fibroids and the presence of dominant fibroids is useful for distinguishing between those cases to be treated by MRgFUS or UAE. Since the introduction of MRgFUS to our unit the percentage non-perfused volumes (NPV) achieved have increased from 41.22 to 50.49 (p=0.038), however the re-intervention rate at 5 years remains high at 50%. MRgFUS has an excellent safety record, and the introduction of the new ExAblate 2100 system also appears to be safe and well tolerated, with encouraging initial NPVs achieved. Following both MRgFUS and UAE circulating interleukin-6 (IL-6) is significantly raised, although this is not affected by the degree of pain experienced or the volume of fibroid treated. Following UAE there is rise in circulating vascular endothelial growth factor (VEGF) seen at one week, however no significant change in VEGF levels is seen following MRgFUS. These changes in VEGF are not related to fibroid volume. Discussion MRgFUS is a safe, well tolerated treatment for uterine fibroids, although re-intervention rate is high. Further developments in this treatment modality may continue to improve outcomes, however at present its routine use cannot be recommended.

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Muller, Vinicius. "Eletrofiação de nanofibras de fibroína da seda como dispositivos adsorventes para microextração em fase sólida." Universidade Estadual do Oeste do Parana, 2014. http://tede.unioeste.br:8080/tede/handle/tede/1847.

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Electrospinning technique was applied in the covering of fused silica fibers by regenerated silk fibroin nanofibers (RSF). The parameters of electrospinning process were evaluated through factorial experimental design 22. This study showed the variables flow of solution and capillary-collector distance were statistically significant in the medium diameter response. The model obtained was validated through variance analysis (ANOVA) and response surface methodology. The material was used at solid phase micro extraction (SPME) in the extraction of samples containing a small chain alcohol, applied at gas chromatography (GC). The recovered device was characterized through Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) and thermal analysis (DSC and TGA). The RSF nanofibers covered fibers were morphologic evaluated through scanning electronic spectroscopy (MEV). The results of MEV showed that was possible to obtain fibers in nanoscale, medium diameter around 304 ± 46 nm. The fibers were also submitted to simulated thermal treatment (100°C to 250°C). There was no fusion between the fibers until 250°C (4 hours of treatment), and a little structural damage. The thermal analysis of FRS and covered FRS nanofibers device showed that the electrospun material maintained the thermal stability, with loss due thermal degradation from 250°C. The GC assay demonstrated the standard SPME covered device didn´t interfere on the suggested method to the alcohol isopropyl analysis (AIS). The times of extraction and desorption were optimized in 20 minutes and 10 minutes, respectively. The methodology was evaluated about linearity and specificity. In the concentration between 10 to 500 ppm of AIS, the method was linear, with R2= 0,9927 and selective, with high resolution between peaks of methanol, AIS and ethyl acetate. Electrospinning process of RSF as covering device showed great potential to use in SPME due its high surface area, thermal stability and easiness process, as well as potential to application in extraction of alcohols and GC analysis.
A técnica de eletrofiação foi aplicada no revestimento de fibras de sílica fundida por nanofibras de fibroína de seda regenerada (FSR). Os parâmetros do processo de eletrofiação foram avaliados por meio de delineamento experimental fatorial 2². Este estudo mostrou que as variáveis vazão da solução e distância entre capilar-coletor foram estatisticamente significativas na resposta diâmetro médio. O modelo obtido foi validado através da análise de variância (ANOVA) e metodologia de superfície de resposta. O material foi empregado em Microextração em Fase Sólida (Solid Phase Microextraction SPME ) na extração de amostras contendo um álcool de cadeia pequena, aplicado em cromatografia gasosa (CG). O dispositivo recoberto foi caracterizado por meio de espectroscopia na região do infravermelho (FTIR-ATR) e análises térmicas (DSC e TGA). As fibras recobertas com nanofibras de FSR foram avaliadas morfologicamente através de microscopia eletrônica de varredura (MEV). Por meio dos resultados das análises de MEV, observou-se que foi possível obter fibras em escala nanométrica, com diâmetro médio em torno de 304 ± 46 nm. As fibras também foram submetidas a tratamento térmico em forno (100°C a 250°C). Não houve fusão das fibras até 250°C (até 4 h de tratamento), e poucos danos estruturais. As análises térmicas da FSR e do dispositivo recoberto com as nanofibras de FSR mostraram que o material eletrofiado manteve a estabilidade térmica, com perda por degradação térmica a partir de 250 °C. Os ensaios em CG demonstraram que o branco com o dispositivo de SPME recoberto não interferiu no método proposto para a análise de álcool isopropílico (AIS). Os tempos de extração e dessorção do analito foram otimizados em 20 min e 10 min, respectivamente. A metodologia foi avaliada quanto à linearidade e especificidade. Na faixa de concentração de 10 a 500 ppm de AIS, o método foi linear, com R=0,9927 e seletivo, apresentando alta resolução entre os picos de metanol, AIS e acetato de etila. O processo de eletrofiação da FSR como recobrimento do dispositivo mostrou grande potencial para emprego em SPME devido a sua grande área superficial, estabilidade térmica e facilidade no processo, bem como potencial para aplicação em extração de alcoóis e análise em CG.

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Harrison-Woolrych, Mira. "Studies of peptide growth factors in uterine fibroids." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295533.

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Jacob, Joseph. "Computer based analysis of diffuse fibrosing lung diseases." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/52803.

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Computer based CT analysis of interstitial lung disease (ILD) may finally have come of age with sophisticated new software algorithms that can analyse CTs of patients with idiopathic pulmonary fibrosis (IPF) with similar, or superior, precision to visual scoring by radiologists. However, the latest iterations of such tools have not been evaluated in large populations or in fibrosing lung diseases (FLD) other than IPF. The investigations in this thesis aimed to identify the role of a computer-based tool CALIPER, compared to visual CT scoring and pulmonary function indices, in predicting prognosis at baseline in a large IPF cohort and across a range of FLDs. A second line of enquiry was exploration of the utility of serial CT as a prognosticator in IPF patients. Visual scores for these investigations were provided by four experienced sub-specialty thoracic radiologists. Baseline CT analysis in IPF demonstrated that CALIPER parameters, particularly the percentage of the lung occupied by vessels (parenchymal vascular percentage - PVP), were strong predictors of pulmonary function indices as well as mortality. CALIPER variables were the strongest predictors of mortality in patients with hypersensitivity pneumonitis and connective tissue disease-related-ILD and were one of the strongest predictors of mortality in an “all-comers” cohort of FLD. Serial evaluation of CT scans demonstrated that change in CALIPER variables, specifically change in PVP, was a stronger and more sensitive predictor of survival than the best available measure of disease worsening in IPF, namely change in forced vital capacity (FVC). It is concluded that CALIPER is a viable complementary tool in the baseline and serial evaluation of IPF and the baseline analysis of the majority of FLDs. Change in PVP, in particular, may represent a new index in the clinical evaluation of disease progression in IPF and could represent a co-endpoint alongside FVC change in clinical trials.

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Sagnella, Anna <1984&gt. "Silk Fibroin: a biopolymer platform for innovative pharmaceutical formulation and biomedical devices." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6906/.

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The protein silk fibroin (SF) from the silkworm Bombyx mori is a FDA-approved biomaterial used over centuries as sutures wire. Importantly, several evidences highlighted the potential of silk biomaterials obtained by using so-called regenerated silk fibroin (RSF) in biomedicine, tissue engineering and drug delivery. Indeed, by a water-based protocol, it is possible to obtain protein water-solution, by extraction and purification of fibroin from silk fibres. Notably, RSF can be processed in a variety of biomaterials forms used in biomedical and technological fields, displaying remarkable properties such as biocompatibility, controllable biodegradability, optical transparency, mechanical robustness. Moreover, RSF biomaterials can be doped and/or chemical functionalized with drugs, optically active molecules, growth factors and/or chemicals In this view, activities of my PhD research program were focused to standardize the process of extraction and purification of protein to get the best physical and chemical characteristics. The analysis of the chemo-physical properties of the fibroin involved both the RSF water-solution and the protein processed in film. Chemo-physical properties have been studied through: vibrational (FT-IR and Raman-FT) and optical (absorption and emission UV-VIS) spectroscopy, nuclear magnetic resonance (1H and 13C NMR), thermal analysis and thermo-gravimetric scan (DSC and TGA). In the last year of my PhD, activities were focused to study and define innovative methods of functionalization of the silk fibroin solution and films. Indeed, research program was the application of different methods of manufacturing approaches of the films of fibroin without the use of harsh treatments and organic solvents. New approaches to doping and chemical functionalization of the silk fibroin were studied. Two different methods have been identified: 1) biodoping that consists in the doping of fibroin with optically active molecules through the addition of fluorescent molecules in the standard diet used for the breeding of silkworms; 2) chemical functionalization via silylation.

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Hofmann, Sandra. "Silk fibroin as a new biomaterial for tissue engineering and drug delivery." kostenfrei, 2007. http://e-collection.ethbib.ethz.ch/view/eth:29941.

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Yang, Luyuan. "Fabrication of ultrathin films from regenerated silk fibroin solution for biomaterial applications." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/fabrication-of-ultrathin-films-from-regenerated-silk-fibroin-solution-for-biomaterial-applications(49e95f65-30d7-44d2-8b70-8e1f164c0137).html.

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Silk fibroin (SF) from the silkworm, Bombyx mori, is a natural fibrous protein with unique mechanical properties, biocompatibility and biodegradability. It has great potential in biomaterial applications for tissue engineering, drug delivery and biomedical devises. Most of the SF based biomaterials (e.g. films, scaffolds, hydrogels and electrospun fibres) are cast from regenerated silk fibroin (RSF) solution. Hence, it is important to acquire a comprehensive and deep understanding of the fibroin solution. This research applied a number of biophysical approaches, aiming to investigate the solution aggregation and interfacial adsorption behaviour of the SF polypeptides in aqueous solution. The methods for fabricating nanometre scale SF films are also explored carefully because well-controlled films and their surfaces enable direct characterisation of their interaction with other molecules and cells. Using the dynamic light scattering (DLS) technique, it was found that the particle size of newly made RSF peptides in solution was around 2.3~6.5 nm and they could remain stable for at least 10 weeks at 4 °C. Factors such as temperature, fibroin concentration, pH, alcohol and metallic ions can directly affect the assembly and aggregation of fibroin polypeptides as well as their solubility and stability in solution. The formation of large aggregation under certain conditions was possibly related to the conformational transition of SF from random coil/α-helix (Silk I) to β-sheets (Silk II). The interfacial adsorption of RSF solution at the SiO2/water interface was monitored by spectroscopic ellipsometry (SE), dual polarisation interferometry (DPI) and neutron reflection (NR). It was revealed that surface excess and thickness increased with concentration and decreased with rising pH and ionic strength. NR measurements revealed that the adsorbed polypeptide layers are characterised by a thin and dense inner region and a thick and diffuse outer region, a feature similar to the adsorbed layers from other polypeptides. The results from SE, DPI and NR are in good agreement. Multilayer ultrathin SF films were fabricated using the layer-by-layer spin coating method and were found to be stable in physiological conditions. The thickness and surface excess of the SF films were tuned by varying the concentrations while coating. Surface biocompatibility as demonstrated by MTT assays varied with the film thickness or the number of layers coated. With the aid of the cationic copolymer MPC30-DEA70, SF films successfully immobilised plasmid DNA, which demonstrates the potential of these multilayer SF films to be used in a drug delivery system. The ultrathin SF films were modified with gelatin (G). Preliminary cell culture experiments with 3T3 fibroblasts demonstrated that SF/G films with 1.2% ~ 20% (w/w) G content promoted cell attachment and proliferation compared with pure SF films. When films contain 10% ~ 20% (w/w) of G, they showed biocompatibility even superior to the pure G films. These enhanced cellular responses must result from improved film stability arising from SF and improved cytocompatibility arising from G.

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Ribeiro, Alline Emannuele Chaves. "Biomassa fibrosa do milho: propriedades e aplicações." Universidade Federal de Goiás, 2017. http://repositorio.bc.ufg.br/tede/handle/tede/7537.

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The aim of the present study was to verify the physical, chemical and microbiological viability of the flour derived from fibrous biomass of maize (FBMF) from the processing of maize flour “biju” type as a new food ingredient; to evaluate the nutritional and technological viability of biscuits, toast and cereal bar produced with the FBMF, by means of the evaluation of its physicochemical, microbiological and sensorial characteristics; and analyze the physicalchemical, microbiological and sensory stabilities of the cereal bar selected as the best in sensory analysis. The fibrous biomass of maize (FBM), obtained in the processing of maize flour “biju” type can be recommended for use as a new ingredient in food products, because it presents no microbiological risk; and it has high nutritional and functional value, mainly because it is rich in dietary fibers, mainly insoluble, and possess high antioxidant capacity. The production of biscuits and toast from the partial replacement of wheat flour (WF) by fibrous biomass of maize flour (FBMF) is nutritionally and technologically viable, since the evaluated samples do not present microbiological risk; have good sensory acceptance; and are source of protein and rich in insoluble dietary fibers. The utilization of the FBMF in cereal bars (CBs) is feasible from technological and nutritional point of view. The formulation CB6 (14 g 100 g-1 FBMF, 8 g 100 g-1 of rice flakes and 8 g 100 g-1 of oat flakes) presented food safety and better sensory profile, and can be classified as a food rich in dietary fiber and protein source, with high nutritional and functional appeal. The temperature and time influence the physicalchemical and sensorial characteristics of the cereal bar stored at 25 and 35 °C for 180 days. Sensory parameters (appearance, color, aroma, texture, taste and overall impression) and intent to purchase of CB were more stable over time for the cereal bar stored at 25 °C. Shelf life of the cereal bar was estimated to be approximately 153 days when maintained at 25 °C, and 87 days when stored at 35 °C.
O presente estudo teve por objetivo verificar a viabilidade física, química e microbiológica da farinha advinda de biomassa fibrosa do milho (FBFM) do processamento da farinha de milho tipo “biju”, como novo ingrediente alimentício; avaliar a viabilidade nutricional e tecnológica de biscoitos, torradas e barra de cereais produzidos com FBFM, por meio da avaliação das suas características físico-químicas, microbiológicas e sensoriais; e analisar a estabilidade físico-química, microbiológica e sensorial da barra de cereais selecionada como a melhor na análise sensorial. A biomassa fibrosa do milho, obtida no processamento da farinha de milho tipo “biju” pode ser recomendada para utilização como novo ingrediente em produtos alimentícios, pois não apresenta risco microbiológico, e possui elevado valor nutricional e funcional, principalmente por ser rica em fibras alimentares, sobretudo insolúveis, e possuir alta capacidade antioxidante. A produção de biscoitos e de torradas a partir da substituição parcial de farinha de trigo (FT) por FBFM mostra-se nutricional e tecnologicamente viável, pois as amostras avaliadas não possuem risco microbiológico; têm boa aceitação sensorial; e são fonte de proteína e rico em fibras alimentares, principalmente insolúveis. A utilização da FBFM em barras de cereais é viável do ponto de vista tecnológico e nutricional. A formulação BC6 (14 g 100 g-1 de FBFM, 8 g 100 g-1 de flocos de arroz e 8 g 100 g-1 de flocos de aveia) apresentou segurança alimentar e melhor perfil sensorial, e pode ser classificada como um alimento rico em fibras e fonte proteica, com elevado apelo nutricional e funcional. A temperatura e o tempo de armazenamento influenciam as características físico-químicas e sensoriais da barra de cereais mantidas a 25 e 35 °C, por 180 dias. Os parâmetros sensoriais (aparência, cor, aroma, textura, sabor e impressão global) e a intenção de compra da BC foram mais estáveis ao longo do tempo para a barra de cereais armazenada a 25 °C. A vida útil da barra de cereais foi estimada em aproximadamente 153 dias quando mantida a 25 °C, e 87 dias quando armazenada a 35 °C.

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46

McMullen, Erin. "Characterization of the large diameter fibers in egg case silk : identification of a core fibroin, TuSp1, and localization of fibroin-like molecules, ECPs, from the black widow spider, latrodectus hesperus." Scholarly Commons, 2008. https://scholarlycommons.pacific.edu/uop_etds/704.

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Araneoid spiders use specialized sets of abdominal silk glands to produce up to seven different types of silks, each with diverse functional properties. At the time of these studies, fibroin eDNA sequences that encode egg case silk had not been reported in the literature. This study used conventional nucleic acid-nucleic acid screening of a eDNA library to isolate a novel gene, named tubuliform spidroin 1 , from the black widow spider Latrodectus hesperus. TuSp 1 was demonstrated to be selectively expressed in the tubuliform gland (the gland suspected for egg case silk production), and examination of the amino acid sequence revealed highly homogeneous repeats (184 amino acid ensemble repeats), a characteristic feature of fibroin sequences. Analyses of the ensemble repeats within the amino acid sequence of TuSp 1 revealed the lack of long stretches of polyalanine and glycine-alanine sub-repeats, which are commonly found in minor ampullate and major ampullate silks. Polyserine blocks and short polyalanine stretches were highly represented in the TuSp 1 amino acid sequence. Our data support the assertion that TuSp 1 represents the main constituent within egg case silk. This supposition is supported by the observation that the amino acid composition of raw egg case silk was strikingly similar to the amino acid composition predicted from the translated TuSp1 eDNA. Two additional constituents identified in black widow egg case, egg case protein 1 (ECP-1) and egg case protein 2 (ECP-2), were also partially characterized in this study. Using immunohistochemical approaches, we demonstrate that ECPs predominantly localize to the exterior of the large diameter fibers of egg cases. Additionally, these studies revealed smaller amounts of ECPs localized to the interior portion of the fibers. Collectively, these results support TuSp1 as the predominant fibroin within egg sacs as well as reveal a structural role for the ECPs, providing clues regarding the supramolecular structure of egg case fibers.

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47

Titinchi, Fadi. "Ossifying fibroma : a clinical and radiological study at the University of the Western Cape Oral Health Centre." Thesis, University of the Western Cape, 2016. http://hdl.handle.net/11394/5258.

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Magister Scientiae Dentium - MSc(Dent)
Ossifying fibroma (OF) is the most frequent of the three fibro-osseous lesions of the jaws. It occurs mostly in patients between the age of 20 and 40 years. Females are more commonly affected than males. Clinically, OF usually presents as a painless expansive intra-bony mass. Swelling and pain may be present in some cases while some lesions are discovered incidentally. Radiographically, OF is usually well-defined and unilocular or multilocular. Early lesions present as well-defined radiolucency that are small in size. Over time, the lesions tend to enlarge in size and become mixed radiolucent-radiopaque and finally become completely radiopaque. The aim of this study was to determine the clinical and radiological features of ossifying fibroma presenting at the Departments of Maxillo-Facial and Oral Surgery and Diagnostics and Radiology, University of the Western Cape Oral Health Centre as well as to assess its management and recurrence patterns. A retrospective case series analysis was performed of all histopathologically diagnosed ossifying fibroma cases available at the Departments of Maxillo-Facial and Oral Surgery and Diagnostics and Radiology at the Faculty of Dentistry, University of the Western Cape from 1976-2014. Patient's age, gender and ethnicity were recorded. The clinical presentation of the lesion as well as the history was analyzed. Radiographic features including density, size, shape, location, locularity and its effect on adjacent structures was noted. Management of each case and follow-up was also documented. A total 61 cases were included in the study. The majority of patients were females (63.9%) and below 40 years of age (73.9%). Few cases were symptomatic (29.5%) with an average period 22 months from first symptoms to presentation. The mandibular posterior region was most affected (55.5%) while larger lesions occurred more frequently in younger patients. Majority of lesions were radiopaque (49.2%) and had well-defined margins (93.6%). Most cases were managed by surgical curettage (68.2%). Following an average follow-up period of 20 months only one case recurred (recurrence rate =6.7%). In conclusion, the majority of the clinical and radiographic findings of ossifying fibroma were similar in South African patients as those of other populations. Differences include that the lesions in this population were more radio-opaque and larger in size than in the reported literature. Surgical curettage is an acceptable management protocol with low rate of recurrence.

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48

Doernte, Amy Lynn. "Spontaneously occurring fibroid tumors of the laying hen oviduct." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/DOERNTE_AMY_2.pdf.

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49

Burroughs, Kevin Dale. "The role of ovarian hormones in the development and growth of uterine leiomyoma /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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50

Martel, Anne. "Agrégation de proteines de soie dans un environnement microfluidique." Grenoble 1, 2008. http://www.theses.fr/2008GRE10314.

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La soie est un biopolymère synthétisé par certains arthropodes. Cette fibre est constituée de protéines arrangées en une microstructure semi-cristalline et possède d'intéressantes propriétés mécaniques. L'axe principal de ce travail de thèse concerne la compréhension du processus de formation de la fibre de soie. La soie de Bombyx mori a été choisi comme modèle. Sa protéine, nommée Fibroïne, a été utilisée pour produire une fibre dans une cellule microfluidique construite pour mimer l'appareil de filage du ver à soie. Le processus de formation de la soie a été suivi par des techniques de diffusion des rayons X (SAXS et WAXS) et par spectroscopie Raman. Elle débute par une étape d'agrégation. La taille des agrégats est de l'ordre de 100 nm. Dans ces particules, la Fibroïne est sous une forme compactée. Cette agrégation est suivie d'une phase de compaction des agrégats. Plus tard, à une échelle de temps de quelques heures, la Fibroïne subit une transition conformationnelle depuis une structure principalement amorphe (Silk I) vers la structure caractéristique de la soie naturelle (Silk II). Ce processus est proposé comme un modèle de la formation de la fibre de soie in vivo. Le second axe de ce travail est orienté vers la connaissance des propriétés physiques de la soie naturelle de B. Mori. Sa résistance aux hautes températures est étudiée d'un point de vue structural, moléculaire et mécanique. L'effet des hautes pressions sur la structure de la fibre de soie est aussi présentée
Silk is a biopolymer spun by several arthropods. This fibre is made of protein arranged in a semi-crystalline microstructure and has remarkable mechanical properties. The main axis of this thesis work concerns the comprehension of silk fibre formation. Bombyx mori silk has been used as a model. The protein component of B. Mori silk, named Fibroin, has been spun into a fibre in a microfluidic device designed to mimic the silkworm spinning apparatus. The silk formation process has been followed by synchrotron radiation scattering (SAXS and WAXS) and Raman spectroscopy. It starts with an aggregation phase. The size of aggregates is around 100 nm. Inside these particles, the Fibroin is compacted. This aggregation is followed by a phase of compaction of the aggregates. Later, within a few hours, the Fibroin undergoes a conformational transition from a mainly amorphous structure (Silk I) to the semi-crystalline structure characteristic of the natural fibre (Silk II). This process is proposed as a possible model of silk formation in vivo. The second axis of this work is dedicated to the investigation of the physical properties of natural B. Mori silk. Its resistance to high temperature is studied from a molecular, structural and mechanical point of view. The semi-crystalline structure of the fibre remains stable up to carbonization although its mechanical properties and the Fibroin's integrity are affected at lower temperature. The effect of high pressure on the fibre structure is also presented : throughout the pressure increase, the crystallites can compact slightly before their disorganization

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