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Previous issue date: 2015-03-31 / Growth factors such as the recombinant human growth hormone are drawing attention on the field of bone reconstruction. However, due to the protein?s short half-life, biodegradable polymers, like PLGA, have been applied seeking a slower and controlled drug release for topical applications.
Objective: To asses, in vitro, the behavior of PLGA matrices with 2 different rhGH concentrations.
Materials and Methods: Three groups of triplicate samples were created: group I with pure PLGA (control), group II with PLGA loaded with a higher rhGH concentration and group III with PLGA loaded with a lower concentration of the hormone. Each group was analyzed macro and microscopically (SEM) and, by means of the hidrolitic degradation test, the dynamics of release of rhGH as well as the alterations on the pH of the incubation medium were evaluated, throughout 29 days.
Results: Matrices from all groups showed indistinguishable macro and microscopic features. Group II released a higher quantity of rhGH, as expected, however there was no clear release pattern on both groups. rhGH release was observed until the 22? day and there was no statistically significant difference on weight loss between the 3 groups. pH values found were clinically viable.
Conclusion: Morphological properties of the matrices must be assessed according to its applications and target-tissue to be substituted/regenerated and it was not possible to determine a pattern of rhGH distribution within PLGA matrices on this survey. The matrices can be used as rhGH carriers and were able to extend hormone release for a period of 22 days. Wheight loss showed equal patterns (statistically), despite the addition of rhGH to the polymer. The pH values were clinically viable and the reduction of rhGH concentrations on future researches should not be carried out using this methodology, possibly owing to limitations on screening with ultra-violet spectroscopy. / Fatores de crescimento como o horm?nio do crescimento humano recombinante v?m ganhando aten??o no campo da reconstru??o ?ssea. No entanto, devido ? sua meia-vida curta, pol?meros biodegrad?veis, como o PLGA, v?m sendo utilizados visando libera??o mais lenta e controlada deste horm?nio quando de sua aplica??o t?pica.
Objetivo: Avaliar, in vitro, o comportamento de matrizes de PLGA com 2 concentra??es diferentes de rhGH.
Materiais e M?todos: Tr?s grupos de amostras em triplicatas foram montados: grupo I com PLGA puro (controle); grupo II com PLGA associado ao rhGH em maior concentra??o e; grupo III com PLGA associado ao rhGH em menor concentra??o. Cada grupo foi analisado macroscopicamente e microscopicamente (MEV) e, por meio de teste de degrada??o hidrol?tica, avaliou-se a din?mica de libera??o do rhGH assim como as altera??es de pH no meio de incuba??o ao longo de 29 dias.
Resultados: As matrizes dos 3 grupos de estudo ficaram com caracter?sticas morfol?gicas indistingu?veis macro e microscopicamente. O grupo II liberou maior quantidade de rhGH que o grupo III, como era o esperado, no entanto, n?o houve um padr?o claro de libera??o em ambos os grupos. A libera??o de rhGH foi observada at? o 22? dia de avalia??o e n?o houve diferen?a estat?stica na perda de massas entre os grupos. Os valores de pH encontrados foram compat?veis com a aplica??o cl?nica.
Conclus?o: As propriedades morfol?gicas devem ser avaliadas conforme a aplica??o do material e do tecido alvo a ser regenerado/substitu?do e n?o foi poss?vel estabelecer um padr?o de distribui??o do rhGH nas matrizes de PLGA neste estudo. As matrizes podem ser utilizadas como carreadoras de rhGH tendo sido capazes de prolongar a libera??o do horm?nio por um per?odo de 22 dias. A perda de massas se manteve igual (estatisticamente), a despeito da adi??o do rhGH ao pol?mero. O pH das amostras se mostrou favor?vel ? aplica??o cl?nica das matrizes e a redu??o nas concentra??es de rhGH para estudos futuros n?o deve ser avaliada por esta metodologia, visto que podem se tornar de dif?cil leitura pelo EAU-Vis.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/6168 |
| Date | 31 March 2015 |
| Creators | Oliveira, Henrique do Couto de |
| Contributors | Pagnoncelli, Rog?rio Miranda |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Odontologia, PUCRS, Brasil, Faculdade de Odontologia |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| 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, 600, 600, 600, 4673435736271820140, -2070498469879244349 |
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