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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Avalia??o do biomaterial de PLGA com horm?nio de crescimento recombinante humano (rhGH) em modelo animal

Garcia, Ricardo Fernandes 08 March 2017 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-26T14:56:31Z No. of bitstreams: 1 TES_RICARDO_FERNANDES_GARCIA_PARCIAL.pdf: 159331 bytes, checksum: aacf8f2e7202562d6ba8bfb886ab0c8d (MD5) / Made available in DSpace on 2017-06-26T14:56:31Z (GMT). No. of bitstreams: 1 TES_RICARDO_FERNANDES_GARCIA_PARCIAL.pdf: 159331 bytes, checksum: aacf8f2e7202562d6ba8bfb886ab0c8d (MD5) Previous issue date: 2017-03-08 / More and more studies are focusing on the combination of matrices that have osteoconductive characteristics with osteoinductive proteins. These proteins can stimulate the differentiation of mesenchymal and osteoprogenitor cells into osteoblasts and thereby increase the migration of cells related to bone formation within the defect site. The main materials used for these purposes are biodegradable polymers, such as PLA (poly lactic acid) and PLGA (poly lactic glycolic acid). Several drugs are used to be released in these systems, such as antibiotics, contraceptives and proteins, including human growth hormone (GH). RhGH in bone tissue promotes the increased deposition of proteins by chondrocytes and osteoblasts, an increase in the number of mitoses and the conversion of chondrocytes into osteoblasts. Thus, it is necessary to evaluate this biomaterial (PLGA \ rhGH) as a controlled release device. Thus achieving the presence of rhGH in the site of bone healing. For this study was used as animal model, wistar rats. The study was carried out in accordance with Law No. 11,794 of October 8, 2008, as well as following the Brazilian Directive of Practice for the Care and Use of Animals for Scientific and Educational Purposes - DBPA of CONCEA. Project approved by CEUA of PUCRS under number 15/00461. Thirty adult wistar rats were used, in which they were submitted to bone defects with Carbide spherical drill number 704, the defect corresponded to the diameter of the drill. The rats were submitted to the same treatment but suffered euthanasia at different times (07, 15 and 20 days). The femurs of the rats were radiographed in the range of 7, 15, and 20 days to gauge the optical density. Slides were then produced for histological analysis, with cuts of approximately 5 ?m thick and stained with hematoxylin / eosin (HE). Three more representative cuts of each blade were chosen. The systemic repercussion of rhgh was assessed through IGF-1 levels through blood collection that was performed before each euthanasia, in the control group and in the experimental group. The blood collected was centrifuged (2500 revolutions per minute for 10 min) and serum obtained stored in a freezer at -20 ? C for further determination of IGF-1 plasma levels using the method based on an enzymatically amplified assay of the " Sandwich, "held at the Senhor dos Passos laboratory in Porto Alegre, RS. For statistical analysis, the Tukey test was applied, 5% significance level and ANOVA variance analysis. There were no statistically significant differences in bone mineral densities, however numerically the PLGA\RhGH grafts always had a greater amount of shades of gray. In conclusion, defects with PLGA\RhGH grafts showed a higher optical density. A higher mineral density compared to the autogenous graft In the histological analyzes there was also no statistically significant difference between the autogenous and PLGA\RhGH grafts. However, by numerical analysis we observed a better and equal performance between the PLGA\RhGH graft and autogenous graft. Defects with PLGA\RhGH grafting probably had faster healing and maturation than autogenous grafts. / Cada vez mais estudos est?o focando a combina??o de matrizes que possuam caracter?sticas osteocondutora com prote?nas osteoindutivas. Essas prote?nas podem estimular a diferencia??o de c?lulas mesenquimais e osteoprogenitoras em osteoblastos e assim aumentar a migra??o de c?lulas relacionadas ? forma??o ?ssea dentro do s?tio do defeito. Os principais materiais utilizados para esses objetivos s?o os pol?meros biodegrad?veis, como o PLA (poli ?cido l?tico) e o PLGA (poli ?cido glic?lico l?tico). Diversas drogas s?o utilizadas para serem liberadas nesses sistemas, como antibi?ticos, anticoncepcionais e prote?nas, incluindo o horm?nio do crescimento humano recombinante (rhGH). O rhGH no tecido ?sseo, promove a deposi??o aumentada de prote?nas pelos condr?citos e osteoblastos, aumento do n?mero de mitoses e a convers?o de condr?citos em osteoblastos. Desta forma se faz necess?rio a avalia??o desse biomaterial (PLGA\rhGH) como dispositivo de libera??o controlada. Conseguindo com isso a presen?a do rhGH intimamente no local da cicatriza??o ?ssea. Para este estudo foi utilizado como modelo animal,ratos wistar. O estudo foi todo realizado de acordo com a Lei N0 11.794, de 8 de outubro de 2008 bem como seguindo a diretriz Brasileira de Pr?tica para o Cuidado e a Utiliza??o de Animais para Fins Cient?ficos e Did?ticos ? DBPA do CONCEA. Projeto aprovado pelo CEUA da PUCRS sob n?mero 15/00461. Foram utilizados trinta ratos wistar adultos, nos quais foram submetidos a defeitos ?sseos nos f?mures com broca, os defeitos tinham todos mais ou menos 05mm de di?metro. Os ratos foram submetidos ao mesmo tratamento, por?m divididos em tr?s grupos de acordo com o tempo das eutan?sia :Grupo 01 eutan?sia em 07dias , Grupo 02 eutan?sia em 15 dias e Grupo 03 eutan?sia em 20 dias. Os f?mures dos ratos foram radiografados no intervalo entre 07, 15, e 20 dias para aferir a densidade ?ptica. Em seguida foram produzidas l?minas para an?lises histol?gicas, com cortes de aproximadamente 5?m de espessura e corados com hematoxilina/eosina (HE). Foram escolhidas tr?s cortes mais representativos de cada l?mina. A repercuss?o sist?mica do rhGH foi avaliada atrav?s dos n?veis de IGFI atrav?s da coleta de sangue que foi realizada antes de cada eutan?sia, no grupo-controle e no grupo experimental. O sangue coletado foi centrifugado (2500 rota??es por minuto por 10 min) e o soro obtido armazenado em freezer a -20?C para posterior determina??o dos n?veis plasm?ticos de IGFI usando o m?todo que se baseia em um ensaio enzimaticamente amplificado do tipo ?sandu?che?, realizado no laborat?rio Senhor dos Passos em Porto Alegre,RS. Para an?lise estat?stica foi aplicado o Teste Tukey, n?vel de 5% de signific?ncia e an?lise de vari?ncia ANOVA. N?o houve diferen?a estatisticamente significante em rela??o as densidades minerais ?sseas, por?m numericamente os enxertos com PLGA\rhGH tiveram sempre uma quantidade maior de tons de cinza. Conclui-se que os defeitos com enxerto de PLGA\rhGH apresentaram uma maior densidade ?ptica e uma maior densidade mineral em compara??o ao enxerto aut?geno. Nas an?lises histol?gicas tamb?m n?o houve diferen?a estatisticamente significante entre os enxertos aut?geno e de PLGA\rhGH. Por?m pelas analises num?ricas observamos um desempenho melhor e/ou igual entre o enxerto de PLGA\rhGH e enxerto aut?geno. Os defeitos com enxerto de PLGA\rhGH, de ocordo com a metodologia empregada, densidade mineral ?ptica e pelas l?minas histol?gicas, observamos uma cicatriza??o e matura??o mais r?pida do que os enxerto aut?genos.

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