Orientadora: Profa. Dra. Christiane Bertachini Lombello / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Biomédica, 2015. / A engenharia de tecidos visa cultivar celulas sobre substratos tridimensionais, para implantacao no organismo, restaurando desta forma partes danificadas. Os materiais utilizados como substratos devem apresentar caracteristicas propicias ao cultivo celular. Na cultura de celulas e necessario o estabelecimento de certas condicoes, como o modo de suplementacao do meio de cultura. Sendo assim, este estudo avaliou sistemas de cultura autologo (coagulo e soro do plasma rico em plaquetas) e xenogeno (gelatina e soro fetal bovino), como substratos e suplementos para a cultura de celulas. O plasma rico em plaquetas (PRP) apos ativacao da cascata de coagulacao apresenta uma estrutura tridimensional, o coagulo. Com a retracao do coagulo, ocorre a liberacao do soro do PRP. A gelatina e uma substancia com capacidade de gelificacao. Para manutencao de sua estrutura, a gelatina foi reticulada com glutaraldeido. A caracterizacao do substrato de gelatina e a liberacao de glutaraldeido foram avaliadas por espectroscopia. Foram realizadas avaliacoes do intumescimento e da degradacao do coagulo e da gelatina por 24 horas e cinco dias, respectivamente. A analise da ultraestrutura dos substratos foi realizada por microscopia eletronica de varredura (MEV). O diametro das fibras do coagulo e a rugosidade superficial da gelatina tambem foram examinados. Para as analises biologicas foram utilizadas celulas Vero. Nas culturas com o coagulo, o meio foi suplementado com 10% do soro do PRP e as culturas com gelatina tiveram o meio suplementado com 10% de SFB. A avaliacao da citotoxicidade foi realizada atraves do teste do extrato e de contato direto das celulas com os substratos. Nas analises do comportamento celular com os substratos, as celulas foram inoculadas sobre o coagulo e a gelatina. As culturas foram mantidas a 37¿C com 5% CO2. As avaliacoes por espectroscopia da gelatina nao identificaram alteracao da estrutura primaria e a presenca do agente reticulador. Os substratos do coagulo e da gelatina exibiram intumescimentos superiores a 200% e ambos demonstraram boa estabilidade, nao apresentando uma degradacao significativa no periodo de cinco dias. A ultraestrutura do coagulo e formada por uma rede irregular de fibras de diferentes diametros, com um valor medio de 0,210}0,097 ¿Êm. A gelatina apresentou uma estrutura densa e plana, exibindo uma micro-rugosidade de 0,11}0,02 ¿Êm. As avaliacoes da citotoxicidade confirmaram que os sistemas de cultura nao foram toxicos para as celulas Vero, exibindo valores de viabilidade celular superiores a 90%. Na analise da interacao celular com os substratos foi verificado que as celulas aderiram e se espalharam sobre os materiais. As celulas presentes na gelatina exibiram maior area superficial (866,32}390,53 ¿Êm) do que as celulas aderidas no coagulo (425,53}245,21 ¿Êm), indicando maior interacao com o substrato. Portanto, os resultados sugerem que ambos os sistemas de cultura sao promissores para utilizacao em engenharia de tecido. Todavia o sistema autologo apresenta a vantagem de ser proprio do organismo. / Tissue engineering aims to grow cells on three dimensional substrates for implantation in the body, restoring damaged parts. The materials used as substrates must have favorable characteristics to the cell culture. In cell culture, it is necessary to establish certain conditions, such as supplementation of the culture medium. Thus, this study evaluated autologous culture systems (clot and serum platelet-rich plasma) and xenogeneic (gelatin and fetal bovine serum) as substrates and supplements for cell culture. The platelet-rich plasma (PRP) upon activation of the coagulation cascade has a three dimensional structure, the fibrin clot. With clot retraction, the serum PRP is released. Gelatin is a substance with gelling capacity. To maintain its structure, gelatin was crosslinked with glutaraldehyde. Characterization of the gelatin substrate and the release glutaraldehyde were assessed by spectroscopy. For the characterization of the substrates were performed assessments of swelling and degradation for 24 hours and five days, respectively. The analysis of the ultrastructure of the substrates was performed by scanning electron microscopy (SEM). The diameter of the clot fiber and the surface roughness of gelatin were also examined. For biological testing, Vero cells were used. In cultures with the clot the medium was supplemented with 10% serum from PRP and gelatin medium were supplemented with 10% FBS. Assessment of cytotoxicity was performed using the test extract and direct contact of the cells with the substrates. In cellular behavior analysis with the substrates, the cells were inoculated onto the clot and gelatin. Cultures were maintained at 37°C with 5% CO2. The evaluations of gelatin by spectroscopy have not identified change in the primary structure and the presence of the crosslinking agent. The substrates of the clot and gelatin exhibited swellings higher than 200% and both demonstrated good stability, showing no significant degradation over a five day period. The ultrastructure of the clot is formed by an irregular network of fibers of different diameters, with an average value of 0.210±0.097 ìm. The gelatin presented a dense and planar structure, showing a micro-roughness of 0.11±0.02 ìm. The evaluation of cytotoxicity confirmed that culture systems were not toxic to Vero cells, exhibiting cell viability higher than 90%. In the analysis of cell interaction with the substrates, was found that the cells adhered and spread on the materials. Cells present in the gelatin exhibited a greater surface area (866.32±390.53 ìm) than the cells adhered in the clot (425.53±245.21 ìm), indicating a greater interaction with the substrate. Therefore, the results suggest that both culture systems are promising for use in tissue engineering. However autologous system has the advantage of being the body itself.
| Identifer | oai:union.ndltd.org:IBICT/oai:BDTD:90451 |
| Date | January 2015 |
| Creators | Ferraraz, Débora Carajiliascov |
| Contributors | Lombello, Christiane Bertachini, Ribeiro, Christiane, Araujo, Daniele Ribeiro |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf, 107 f. : il. |
| Source | reponame:Repositório Institucional da UFABC, instname:Universidade Federal do ABC, instacron:UFABC |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=90451&midiaext=71997, http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=90451&midiaext=71998, Cover: http://biblioteca.ufabc.edu.brphp/capa.php?obra=90451 |
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