Made available in DSpace on 2014-12-17T15:30:56Z (GMT). No. of bitstreams: 1 RodrigoGV_DISSERT.pdf: 1378162 bytes, checksum: aa53c22bf2541e2d42d5b5659f380375 (MD5) Previous issue date: 2011-02-04 / Cryopreservation is a process where cells or biological tissues are preserved by freezing at very low temperatures and aims to cease reversibly, in a controlled manner, all the biological functions of living tissues, i.e., maintain cell preservation so that it can recover with high degree of viability and functional integrity. This study aimed to evaluate the influence of cryopreservation on the mesenchymal stem cells originating from the periodontal ligament of human third molars by in vitro experiments. Six healthy teeth were removed and the periodontal cells grown in culture medium containing α-MEM supplemented with antibiotics and 15% FBS in a humidified atmosphere with 5% CO2 at 37? C. Cells isolated from each sample were divided into two groups: Group I - immediate cell culture (not fresh cryopreserved cells) and Group II - cell cryopreservation, during a period of 30 days. Analyses of rates of cell adhesion and proliferation in different groups were performed by counting the cells adhered to the wells, in intervals of 24, 48 and 72 hours after the start of cultivation. The number of cells in each well was obtained by counting viable cells with the use of hemocytometer and the method of exclusion of cells stained by trypan blue. The difference between groups for each of the times was analyzed by Wilcoxon test. Regarding the temporal evolution for each group, analysis was done by Friedman's test to verify the existence of differences between times and, when it existed, the Wilcoxon penalty was applied. The results showed no statistically significant difference between the two groups analyzed in this study. Therefore, we conclude that the cryopreservation process, after a period of 30 days, did not influence the cell type studied, and there was no difference in growth capacity in vitro between the groups / A criopreserva??o ? um processo em que c?lulas ou tecidos biol?gicos s?o preservados atrav?s do congelamento a temperaturas muito baixas e objetiva cessar reversivelmente, de forma controlada, todas as fun??es biol?gicas dos tecidos vivos; ou seja, manter a preserva??o celular de maneira que esta possa recuperar-se com alto grau de viabilidade e integridade funcional. Este trabalho se prop?s avaliar in vitro a influ?ncia da criopreserva??o nas c?lulas mesenquimais indiferenciadas procedentes do ligamento periodontal de terceiros molares humanos. Para tanto, foram utilizados 6 dentes sadios os quais tiveram as referidas c?lulas removidas e cultivadas em meio de cultura α-MEM contendo antibi?ticos e suplementado com 15% de FBS, em atmosfera ?mida com 5% de CO2 a 37? C. As c?lulas isoladas de cada amostra foram divididas em dois grupos: Grupo I cultivo celular imediato (c?lulas frescas n?o criopreservadas) e Grupo II criopreserva??o celular, durante um per?odo de 30 dias. As an?lises dos ?ndices de ades?o e prolifera??o celular nos diferentes grupos foram realizadas atrav?s das contagens das c?lulas aderidas ?s superf?cies dos po?os de cultivo celular, nos intervalos de 24, 48 e 72 horas ap?s o in?cio do cultivo. O n?mero de c?lulas em cada po?o foi obtido pela contagem das c?lulas vi?veis atrav?s do uso do hemocit?metro e o m?todo de exclus?o das c?lulas coradas pelo azul de trypan. A diferen?a entre os grupos para cada um dos tempos foi analisada pelo teste de Wilcoxon. Em rela??o ? evolu??o temporal para cada um dos grupos, a an?lise foi feita pelo teste de Friedman para verificar a exist?ncia de diferen?a entre os tempos e, quando ela existiu, foi aplicado o teste de Wilcoxon com penaliza??o. Os resultados demonstraram que n?o houve diferen?a estatisticamente significativa entre os dois grupos analisados neste estudo. Portanto, conclui-se que o processo de criopreserva??o, ap?s um per?odo de 30 dias, n?o exerceu influ?ncia no tipo celular estudado; n?o havendo, portanto, nenhuma diferen?a na capacidade de crescimento in vitro entre os grupos