Navegando por Palavras-chave "Marine Sponge"

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    Caracterização físico-química e avaliação do efeito biológico da biosilica proveniente da espécie de esponja marinha tedania ignis
    (Universidade Federal de São Paulo, 2018-09-21) Cruz, Matheus de Almeida [UNIFESP]; Renno, Ana Claudia Muniz [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Bone fractures are an important event in the medical clinic and are mainly related to the occurrence of trauma, accidents, sports injuries and diseases. In this context, biomaterials have been gaining prominence as an alternative in the treatment of fractures, especially the active bioglass 45S5, which is considered the gold standard of performance in the treatment of fractures. However, the great problem of this resource is due to its high cost of manufacturing or importation, which makes its access to the population restricted. Thus, research that seeks to prospect for natural products that have a good performance in bone repair becomes more and more necessary. In this context, marine sponges, which are already the marine organisms most used in medical research, present in their skeleton an organic portion, which is an analogue of collagen type XIII called spongin, in addition to an inorganic portion called Biosilica (BS), which makes up the spicules of these marine organisms. In this context, the objective of this work was: (i) to characterize physicochemically the BS and (ii) evaluate the biological effect of BS by in vivo analyzes. BG 45S5 was used for comparison in both cases. The characterization was done through MEV / EDX, XRD, FTIR, Calcium test and pH. For the in vivo tests, histopathological, histomorphometric and three-point biomechanical tests were performed. The results of SEM / EDX indicated that BS, after its extraction, showed spike structures with presence of Si (Silica) and O (oxygen) elements in its composition, while BG presented particles of varying size and shape with presence of the elements Si (Silica), O (Oxygen), Ca (Calcium), Na (Sodium), Al (Aluminum), Mg (Magnesium) and P (Phosphorus). In the FTIR results, it was possible to observe peaks referring to the groups Si-OH and Si-O-Si in BS and BG, besides the BG present a peak referring to the P-O. The XRD spectrum demonstrated the predominantly amorphous character of BS, but still with crystalline peaks characteristic of silica containing samples, while BG was completely amorphous. In the Ca assay, BS on day 1 demonstrated mineralization while BG demonstrated ion release from the incubation solution. However, from day 3, BS and BG demonstrated to release Ca in the incubator solution, this process being more prominent in BG until the last period. The pH analyzes allowed to observe that BS acidified the incubation medium on day 1 and, from the third day, the same reached a plateau near the physiological pH, while BG demonstrated to alkalinize the medium of day 1 until day 21. The results of the histopathological analysis, in tibiae of rats after 15 days, demonstrated extensive formation of bone tissue in Control Group (GC), presenting areas of osteoid tissue. BS demonstrated to be biocompatible, with initial formation of neoformed bone tissue, mainly in the periphery of the defect, presenting osteoid tissue, besides extensive formation of granulation tissue organized around BS particles. BG presented areas of formation of neoformed bone tissue largely than BS, with a large volume of osteoid tissue interspersed by BG particles and less evident granulation tissue. The histomorphometric parameter for the osteoblastic surface (Ob.S / BSf) demonstrated the bioactivity and anabolic effect of Biosilica. Biomechanical analysis demonstrated good mechanical properties of BS. Finally, it was possible to conclude that BS may present great potential in the fracture repair process, however, more biological studies with longer experimental periods and with different forms of presentation of the material are still necessary, in order to elucidate the mechanisms involved in the repair and to optimize the performance of this new material.