Biocompatibilidade in vivo de membranas nanoestruturadas de quitosana/peo

Electrospinning is a technique that allows the preparation of nanofibers from various materials. Chitosan is a natural and abundant easily obtained polymer, which, in addition to those features, proved to be biocompatible. This work used nanostructured chitosan and polyoxyethylene membranes as subcutaneous implants in Wistar rats to evaluate the biocompatibility of the material. Samples of the material and tissues adjacent to the implant were collected 7, 15, 30, 45 and 60 days post-implantation. Macroscopic integration of the material to the tissues was observed in the samples and slides for histopathological examination that were prepared. It was noticed that the material does not stimulate the formation of adherences to the surrounding tissues and that there is initial predominance of neutrophilia and lymphocytosis, with a declining trend according to the increase of time, featuring a non-persistent acute inflammatory process. However, the material showed fast degradation, impairing the macroscopic observation after fifteen days of implantation. It was concluded that the material is biocompatible and that new studies should be conducted, modifying the time of degradation by changes in obtaining methods and verifying the biocompatibility in specific tissues for biomedical applications674A eletrofiação é uma técnica que permite a preparação de nanofibras mediante o uso de diversos materiais. A quitosana é um polímero natural, abundante e de fácil obtenção, que, além dessas características, demonstrou ser biocompatível. Este trabalho utilizou membranas nanoestruturadas de quitosana e polióxido de etileno como implantes subcutâneos em ratos Wistar para avaliar a biocompatibilidade do biomaterial. As amostras do material e de tecidos adjacentes ao implante foram retiradas sete, 15, 30, 45 e 60 dias pós-implantação para a observação da integração macroscópica do material aos tecidos e para a preparação de lâminas para exame histopatológico. Verificou-se que o material não estimula a formação de aderências com os tecidos circunvizinhos e que há predominância inicial de neutrofilia e linfocitose, que tendem a decrescer em razão do aumento do tempo, caracterizando um processo inflamatório agudo não persistente. No entanto, o material apresentou degradação rápida, não sendo possível observá-lo macroscopicamente após 15 dias de implantação. Concluiu-se que o material é biocompatível, o que indica que novos estudos devem ser conduzidos, com modificação do tempo de degradação por alterações nos métodos de obtenção e verificação da biocompatibilidade em tecidos específicos para aplicações biomédica

In vivo biocompatibility of nanostructured Chitosan/Peo membranes

Electrospinning is a technique that allows the preparation of nanofibers from various materials. Chitosan is a natural and abundant easily obtained polymer, which, in addition to those features, proved to be biocompatible. This work used nanostructured chitosan and polyoxyethylene membranes as subcutaneous implants in Wistar rats to evaluate the biocompatibility of the material. Samples of the material and tissues adjacent to the implant were collected 7, 15, 30, 45 and 60 days post-implantation. Macroscopic integration of the material to the tissues was observed in the samples and slides for histopathological examination that were prepared. It was noticed that the material does not stimulate the formation of adherences to the surrounding tissues and that there is initial predominance of neutrophilia and lymphocytosis, with a declining trend according to the increase of time, featuring a non-persistent acute inflammatory process. However, the material showed fast degradation, impairing the macroscopic observation after fifteen days of implantation. It was concluded that the material is biocompatible and that new studies should be conducted, modifying the time of degradation by changes in obtaining methods and verifying the biocompatibility in specific tissues for biomedical applications

Digestibilidade de dietas e balanços metabólicos de suínos alimentados com dietas contendo aflatoxinas Diets digestibility and metabolic balances of pigs fed diets containing aflatoxins

Um experimento foi realizado para avaliar a digestibilidade de dietas e balanços metabólicos de suínos alimentados com dietas contendo 800ug kg-1 de aflatoxinas. Foram utilizados oito suínos, meio-irmãos, com peso médio inicial de 13kg, alojados em gaiolas metabólicas, em ambiente semi-climatizado. O delineamento experimental foi inteiramente casualizado, com dois tratamentos (dieta controle e controle + 800ug kg-1 de aflatoxinas) e quatro repetições, sendo o animal a unidade experimental. Os coeficientes de digestibilidade da matéria seca, proteína e energia bruta não foram influenciados (P>0,05) pela adição de 800ug kg-1 de aflatoxinas na dieta. A metabolização da energia bruta foi 6% superior (P<0,05) quando comparada à dieta controle. A excreção urinária de N aumentou (P<0,05) em 52% e a retenção relativa à absorção diminuiu (P<0,05) em 31% nos animais alimentados com a dieta contendo aflatoxinas. No balanço energético, a energia bruta ingerida não foi influenciada (P>0,05) pela adição de aflatoxinas. A excreção urinária de energia aumentou (P<0,05) 52% nos animais alimentados com a dieta contendo aflatoxinas. A presença de 800ug kg-1 de aflatoxinas na dieta não afetou a digestibilidade, mas alterou o metabolismo protéico e energético de leitões.<br>An experiment was conducted in order to investigate the digestibility of diets and metabolic balances of piglets fed diets containing 800ug kg-1 of aflatoxins. This study used eight with littermate barrows whith an average initial weight of 13kg, housed in metabolic cages in a semi-acclimatized environment. A completely randomized experimental design was used, with two treatments (control diet and control + 800ug kg-1 of aflatoxins) and four replications, with the animal as the experimental unit. The digestibility coefficients of dry matter, protein and gross energy were not affected (P>0.05) by the addition of 800ug kg-1 of aflatoxins in the diet. The gross energy metabolization was 6% (P<0.05) higher when compared to the control diet. The N urinary losses increased (P<0.05) 52% and the retention related to absorption decreased (P<0.05) 31% in piglets fed diet containing aflatoxins. Concerning the energy balance, the gross energy digested was not influenced (P>0.05) by the addition of aflatoxins in the diet. Energy losses in urine increased (P<0.05) 52% in the pigs fed diets containing aflatoxins. The presence of an aflatoxin level of 800ug kg-1 in the diet did not affect the digestibility, but it altered the protein and energy metabolism of weaned piglets