The aim of the present study was to evaluate the use of collagen, elastin, or chitosan biomaterial for bone reconstruction in rats submitted or not to experimental alcoholism. Wistar male rats were divided into eight groups, submitted to chronic alcohol ingestion (G5 to G8) or not (G1 to G4). Nasal bone defects were filled with clot in animals of G1 and G5 and with collagen, elastin, and chitosan grafts in G2/G6, G3/G7, and G4/G8, respectively. Six weeks after, all specimens underwent radiographic, tomographic, and microscopic evaluations. Bone mineral density was lower in the defect area in alcoholic animals compared to the abstainer animals. Bone neoformation was greater in the abstainer groups receiving the elastin membrane and in abstainer and alcoholic rats receiving the chitosan membrane (15.78 ± 1.19, 27.81 ± 0.91, 47.29 ± 0.97, 42.69 ± 1.52, 13.81 ± 1.60, 18.59 ± 1.37, 16.54 ± 0.89, and 37.06 ± 1.17 in G1 to G8, respectively). In conclusion, osteogenesis and bone density were more expressive after the application of the elastin matrix in abstainer animals and of the chitosan matrix in both abstainer and alcoholic animals. Chronic alcohol ingestion resulted in lower bone formation and greater formation of fibrous connective tissue.
Autologous bone grafts, used mainly in extensive bone loss, are considered the gold standard treatment in regenerative medicine, but still have limitations mainly in relation to the amount of bone available, donor area, morbidity and creation of additional surgical area. This fact encourages tissue engineering in relation to the need to develop new biomaterials, from sources other than the individual himself. Therefore, the present study aimed to investigate the effects of an elastin and collagen matrix on the bone repair process in critical size defects in rat calvaria. The animals (Wistar rats, n = 30) were submitted to a surgical procedure to create the bone defect and were divided into three groups: Control Group (CG, n = 10), defects filled with blood clot; E24/37 Group (E24/37, n = 10), defects filled with bovine elastin matrix hydrolyzed for 24 h at 37 °C and C24/25 Group (C24/25, n = 10), defects filled with porcine collagen matrix hydrolyzed for 24 h at 25 °C. Macroscopic and radiographic analyses demonstrated the absence of inflammatory signs and infection. Microtomographical 2D and 3D images showed centripetal bone growth and restricted margins of the bone defect. Histologically, the images confirmed the pattern of bone deposition at the margins of the remaining bone and without complete closure by bone tissue. In the morphometric analysis, the groups E24/37 and C24/25 (13.68 ± 1.44; 53.20 ± 4.47, respectively) showed statistically significant differences in relation to the CG (5.86 ± 2.87). It was concluded that the matrices used as scaffolds are biocompatible and increase the formation of new bone in a critical size defect, with greater formation in the polymer derived from the intestinal serous layer of porcine origin (C24/25).
A creatina pode promover efeitos ergogênicos na prática do exercício físico de alta intensidade, entretanto, são encontradas poucas evidências que relatam a respeito dos efeitos morfométricos e estereológicos da associação desses componentes em modelos experimentais. Para isso, foram selecionados 24 ratos Wistar que se encontravam com idade de 15 semanas e estavam sob condições de alimentação e hidratação controladas. Para verificar as modificações morfométricas e estereológicas foi feita a classificação dos animais em quatro grupos: o controle, suplementado, treinamento, e treinamento e suplementado. Os animais dos grupos com suplementação de creatina foram suplementados (via gavagem) nas dosagens de 300 mg/kg de massa corporal durante nove semanas, sendo o período igual de treinamento que os animais que foram treinados estiveram submetidos, com o programa de treinamento baseado nos estudos de Honenberg & Farrar. Após o período de experimentação, os animais repousaram por 48 horas e foram feitas as excisões dos músculos latíssimo do dorso e bíceps braquial, que posteriormente foram submetidos ao protocolo de cortes histológicos em criostato, seguido da coloração em hematoxilina e eosina. Os resultados morfométricos indicaram poucas modificações da área nuclear para os grupos do experimento, apresentando diferença estatística apenas no grupo treinado e suplementado em relação aos outros grupos do estudo. A perimetria sarcoplasmática foi mais evidente também no grupo submetido a ambos tratamentos. A análise estereológica verificou a presença de alguns fagócitos mononucleares no tecido muscular, sem, entretanto, apresentar condições de inflamação tecidual severa. Conclui-se, portanto, que a creatina apresenta efeitos morfométricos mais evidentes quando associada ao treinamento de força.Palavras-chave: exercício, creatina, técnicas histológicas, anatomia e histologia.
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