Efeito modulador da radiação ionizante sobre citocinas sanguíneas e células do tecido ósseo na interface osso-implante
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Data
2018-05-02
Autores
Vegian, Mariana Raquel da Cruz
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Implantes osseointegrados são considerados efetivos como tratamento reabilitador. Contudo, vários fatores podem prejudicar o sítio receptor, entre eles, a radiação ionizante. Entretanto, os mecanismos pelos quais estes eventos acontecem ainda não foram completamente esclarecidos. O objetivo neste estudo foi avaliar o efeito modulador da radioção ionizante, simulando uma dose total de um tratamento radioterápico convencional para pacientes oncológicos, nos níveis de citocinas sanguíneas e na remodelação óssea da interface ao redor do implante. Foram utilizados 45 ratos que receberam implantes rosqueados de titânio grau V nos fêmures direito. Os animais foram divididos em 3 grupos: a) Grupo Sem-Irradiação (S-Ir): grupo controle apenas com implante. b) Grupo Irradiação Posterior (IrPos): implante + irradiação; c) Grupo Irradiação Prévia (IrPrev): irradiação + implante. Os animais dos grupos IrPos e IrPrev foram submetidos a irradiação em 2 etapas fracionadas de 15 Gy. Nos períodos de 3 dias, 2 semanas e 7 semanas após o último procedimento, 05 animais foram eutanasiados aleatoriamente por grupo. Os níveis séricos de TNF-ɑ, IL-1β e IL-10 foram mensurados a partir do sangue coletado previamente ao momento da eutanásia pelo método imunoenzimático (ELISA). As peças contendo os implantes foram submetidos à marcação imuno-histoquímica utilizando os marcadores para TRAP e osteocalcina (OC). O teste ANOVA foi utilizado para análise estatística e quando necessário foi aplicado o teste de comparação múltipla de Tukey (p<0,05). O grupo IrPos exibiu diferença estatística (p<0,05) com S-Ir e IrPrev nos valores de TNF-α em 2 e 7 semanas, enquanto IrPrev diferiu estatisticamente (p<0,05) de S-Ir nos valores de IL-10, em 3 dias. A análise imuno-histoquímica da interface osso-implante, demonstrou valores mais altos de TRAP e OC nos grupos irradiados, com diferença estatística (p<0,05), entre os valores de TRAP de S-Ir e IrPos em 3 dias e entre S-Ir e IrPrev em todos os períodos, e de OC entre S-Ir e IrPos em 3 dias e entre S-Ir e IrPrev em 2 semanas. Em suma, os resultados desse estudo indicaram que a radiação ionizante alterou produções de citocinas sanguíneas pró e anti-inflamatórias após lesão cirúrgica de colocação do implante e influenciou na expressão de proteínas envolvidas na remodelação óssea.
Osseointegrated implants are considered effective as a rehabilitative treatment. However, several factors may impair the receptor site, including ionizing radiation. However, the mechanisms by which these events occur have not yet been fully elucidated. The objective of this study was to evaluate the modulating effect of radiotherapy, simulating a total dose of a conventional ionizing radiation treatment for cancer patients, blood cytokine levels and bone remodeling of the interface around the implant. Forty-five rats were submitted to grade V titanium implants in the right femurs. The animals were divided into three groups: a)No Irradiation group (N-Ir): control group with only the implant b) Previous irradiation group (Prev-Ir): implant + irradiation; c) Posterior Irradiation group (Pos-Ir): irradiation + implant. Pos-Ir and Prev-Ir groups were irradiated in 2 fractional stages of 15 Gy. At 3 days, 2 weeks and 7 weeks after the last procedure, 05 animals were randomly euthanized per group. Serum levels of TNF-ɑ, IL-1β and IL-10 were measured from blood collected prior to euthanasia using the enzyme-linked immunosorbent assay (ELISA). The pieces containing the implants were subjected to immunohistochemical labeling using the markers for TRAP and osteocalcin (OC). The ANOVA test was used for statistical analysis and when necessary the Tukey multiple comparison test (p <0.05) was applied. The Pos-Ir group exhibited a statistical difference (p <0.05) with N-Ir and Prev-Ir in TNF-α values at 2 and 7 weeks, whereas Prev-Ir differed statistically (p <0.05) from N-Ir in IL-10 values, in 3 days. The immunohistochemical analysis of the bone-implant interface demonstrated higher values of TRAP and OC in the irradiated groups, with a statistical difference (p <0.05) between the values of TRAP of N-Ir and Pos-Ir in 3 days and between N-Ir and Prev-Ir in all periods, and OC between N-Ir and Pos-Ir in 3 days and between N-Ir and Prev-Ir in 2 weeks. In summary, the results of this study indicated that irradiation altered productions of pro and anti-inflammatory blood cytokines after surgical lesion of implant placement and influenced the expression of proteins involved in bone remodeling.
Osseointegrated implants are considered effective as a rehabilitative treatment. However, several factors may impair the receptor site, including ionizing radiation. However, the mechanisms by which these events occur have not yet been fully elucidated. The objective of this study was to evaluate the modulating effect of radiotherapy, simulating a total dose of a conventional ionizing radiation treatment for cancer patients, blood cytokine levels and bone remodeling of the interface around the implant. Forty-five rats were submitted to grade V titanium implants in the right femurs. The animals were divided into three groups: a)No Irradiation group (N-Ir): control group with only the implant b) Previous irradiation group (Prev-Ir): implant + irradiation; c) Posterior Irradiation group (Pos-Ir): irradiation + implant. Pos-Ir and Prev-Ir groups were irradiated in 2 fractional stages of 15 Gy. At 3 days, 2 weeks and 7 weeks after the last procedure, 05 animals were randomly euthanized per group. Serum levels of TNF-ɑ, IL-1β and IL-10 were measured from blood collected prior to euthanasia using the enzyme-linked immunosorbent assay (ELISA). The pieces containing the implants were subjected to immunohistochemical labeling using the markers for TRAP and osteocalcin (OC). The ANOVA test was used for statistical analysis and when necessary the Tukey multiple comparison test (p <0.05) was applied. The Pos-Ir group exhibited a statistical difference (p <0.05) with N-Ir and Prev-Ir in TNF-α values at 2 and 7 weeks, whereas Prev-Ir differed statistically (p <0.05) from N-Ir in IL-10 values, in 3 days. The immunohistochemical analysis of the bone-implant interface demonstrated higher values of TRAP and OC in the irradiated groups, with a statistical difference (p <0.05) between the values of TRAP of N-Ir and Pos-Ir in 3 days and between N-Ir and Prev-Ir in all periods, and OC between N-Ir and Pos-Ir in 3 days and between N-Ir and Prev-Ir in 2 weeks. In summary, the results of this study indicated that irradiation altered productions of pro and anti-inflammatory blood cytokines after surgical lesion of implant placement and influenced the expression of proteins involved in bone remodeling.
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Palavras-chave
Remodelação óssea, Implantes de titânio, citocinas, osseointegração, Imuno-histoquímica, Bone remodeling, Implants of titanium, Cytokines, osseointegration, immunohistochemistry