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

Histomorphological evaluation of the digital coronary region at different fetal development stages of Holstein cattle

The scientific literature lacks detailed morphological descriptions of the histological development and cell differentiation of fetal bovine hoof. In this study, 40 extremity members of Holstein bovine fetuses were collected and divided into four groups (G1 to G4) based on the estimated age. Fragments were removed from wall and sole, processed and stained with hematoxylin - eosin (HE) for light microscopy observation. In G1, it was found that the epidermis was very thin, including keratinocyte layers and clusters of mesenchymal cells. In group G2 it was observed that the thickness of the epidermis covering the limbs remained variable and laminar corium developed in the germinal layer. In group G3 it was noted that in the germinal epithelium there were papillae in little advanced development and cells of the stratum corneum in the initial process of keratinization. In G4, the epidermis was well developed with layers distributed homogeneously, containing symmetrical and long papillae and intense production of keratin. In this work, the most important cellular events for the formation of the fetal hoof in Holstein cattle were first described in different stages of their formation

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

Development and evaluation of accessories to improve the posture of veterinary surgeons in surgical procedures conducted in the field

ABSTRACT The study was conducted based on the information collected on rural properties in the state of Goiás, during practical classes of Surgical Clinic in Large Animals at the Veterinary Hospital of the Escola de Veterinária e Zootecnia of the Universidade Federal de Goiás and during the implementation of outreach projects developed by the institution. An acropostite-phimosis surgical procedure in the bulls in the field was selected, lasting over 30 minutes and requiring movements, posture and strength on the part of the surgeon. Devices were proposed and developed to provide improved comfort and safety to surgeons. The first device was a stool to be used by the professional during the execution of the surgical intervention. The use enabled the surgeon to sit down and rest their feet on the ground, reducing knee bending and distributing the support forces in various muscle groups. For the movement restriction of the surgeon, another accessory was developed to support the foreskin of the animal. Made of wood, this other device serves as a support for keeping the foreskin away from the ground and close to the surgeon. Its length, width and thickness established a good relation with the stool height, providing minimal discomfort to the professional. The third device was designed to assist in the immobilization of the animal and increase safety for the patient and surgical team. A fourth accessory was designed to protect the scapular region and avoid the occurrence of injuries in the radial nerve, myopathies and traumas during the rollover or prolonged stay of the animal in lateral decubitus. The choice of the shape, dimensions and softness of the device was mainly based on the weight of the animal. Such devices have proven to be effective, reducing the time of surgery, making cervical and lumbar movement easier, in addition to providing better support to the surgeon, reducing risks of musculoskeletal diseases