Made available in DSpace on 2015-04-14T13:30:32Z (GMT). No. of bitstreams: 1
458211.pdf: 2390147 bytes, checksum: 88c6a01bcd87265c68297af0c6ea8e78 (MD5)
Previous issue date: 2014-03-27 / Bioresorbable polymers have been used as scaffolds in tissue engineering, thus representing an important alternative for reconstruction of lesions and tissue losses. This study aimed to evaluate the in vivo performance of three-dimensional scaffolds made of polycaprolactone (PCL), by means of through a PCL implant on the subcutaneous tissues of rats back and calvaria, as well as the reaction of their kidneys, lungs and liver. The histological analysis of the bone repair process in calvaria showed the presence of newly formed bone growing towards the center of the defects. The formation of a thin fibrous capsule was observed in the tissues adjacent to the scaffold implanted on the back of all animals, with collagenous fibers involving the implant. As for events occurring in animals' kidneys, lungs and liver, there were no harmful tissue alterations in these organs nor the presence of inflammatory process, hyperplasia, metaplasia, dysplasia or hemorrhage. A quantitative analysis of the bone repair process was performed using histomorphometry and cone beam computed tomography (CBCT). Results showed that the newly formed bone grew towards the center of the defects. Statistical analysis revealed that the total area of new bone formation was greater in experimental defects at 21, 60 and 120 days, showing a statistically significant difference. In tomographic analysis found that new bone formation is more likely to occur in experimental defects, but with no statistically significant difference. Considering tomographic analysis as a new method for the assessment of new bone formation, the data obtained from this assessment could not be correlated with those obtained from histomorphometric analysis. Therefore, it can be concluded that PCL scaffolds produced on an additive manufacturing machine are biocompatible, non-cytotoxic and bioresorbable products that promote osteoconduction. PCL showed great potential for clinical use in the treatment of bone defects by increasing bone ?rea and seems to be an appropriate biomaterial to be used in other studies aiming to elucidate issues related to this topic. Additionally, CBCT does not seem to be a useful tool in the evaluation of new bone formation of rat calvaria, which means that histomorphometric analysis is still the most appropriate method. / Pol?meros biorreabsorv?veis v?m sendo utilizados como scaffolds na engenharia tecidual, destacando-se como alternativa para reconstru??o de les?es e perdas teciduais. Neste estudo, avaliou-se o desempenho in vivo de scaffolds tridimensionais de pol?mero policaprolactona (PCL), atrav?s do implante do PCL nos tecidos subcut?neos do dorso e na calv?ria, bem como da rea??o dos ?rg?os rins, pulm?es e f?gado de ratos. A an?lise histol?gica qualitativa do processo de reparo ?sseo nas calv?rias mostrou neoforma??o ?ssea e que o osso neoformado cresceu em dire??o ao centro de defeitos. Nos tecidos adjacentes ao scaffold implantado no dorso, percebeu-se que em todos os animais houve forma??o de c?psula fibrosa fina, com fibras col?genas organizadas envolvendo o implante. Com rela??o aos eventos ocorridos nos rins, f?gado e pulm?es dos animais, n?o houve altera??es teciduais danosas aos ?rg?os, tampouco a presen?a de processo inflamat?rio, hiperplasia, metaplasia, displasia ou hemorragia. A an?lise quantitativa do processo de reparo ?sseo foi realizada atrav?s de histomorfometria e tomografia computadorizada de feixe c?nico (TCFC). Ap?s an?lise estat?stica, a ?rea total de neoforma??o ?ssea em mm2 foi maior nos defeitos experimentais aos 21, 60 e 120 dias, com diferen?a estatisticamente significativa. Na an?lise tomogr?fica, percebeu-se uma tend?ncia de maior neoforma??o ?ssea nos defeitos experimentais, mas sem diferen?a estatisticamente significativa. Considerando-se a an?lise tomogr?fica como uma nova metodologia para avalia??o de neoforma??o ?ssea, os dados obtidos atrav?s dessa avalia??o n?o puderam ser correlacionados com aqueles obtidos na an?lise histomorfom?trica. Portanto, conclui-se que os scaffolds de PCL produzidos na plataforma experimental de manufatura aditiva s?o biocompat?veis, n?o citot?xicos, biorreabsorv?veis e promovem osteocondu??o. O PCL apresentou grande potencial de aplica??o cl?nica nos defeitos onde se espera aumentar a ?rea ?ssea e parece adequado como um biomaterial de escolha para outros estudos que elucidem as quest?es pertinentes. A TCFC n?o parece ser uma ferramenta ?til na avalia??o da neoforma??o ?ssea em calv?ria de ratos, de modo que a an?lise histomorfom?trica permanece como m?todo mais adequado.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/1248 |
| Date | 27 March 2014 |
| Creators | Hirsch, W?neza Dias Borges |
| Contributors | Heitz, Claiton |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Odontologia, PUCRS, BR, Faculdade de Odontologia |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | -8096554818733665164, 500, 600, 4673435736271820140 |
Page generated in 0.0022 seconds