Navegando por Palavras-chave "Esponjas Marinhas"
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- ItemAcesso aberto (Open Access)Análise do potencial anticâncer de extratos obtidos de esponjas marinhas de Fernando de Noronha(Universidade Federal de São Paulo, 2021-03-29) Santos, Letícia Schmitz Saraiva [UNIFESP]; Jimenez, Paula Christine [UNIFESP]; http://lattes.cnpq.br/4248251483705135; http://lattes.cnpq.br/4552158300334014; Universidade Federal de São Paulo (UNIFESP)A natureza vem contribuindo há tempos com recursos e inspirações para busca de compostos com funções terapêuticas. Sobretudo, o oceano tem demonstrado ser um ambiente de grande significância nestas descobertas devido à biodiversidade extremamente rica presente. As esponjas marinhas figuram entre os grupos de organismos mais estudados por seu potencial farmacológico, sendo inclusive representadas por dois dos oito medicamentos aprovados para tratamento de câncer (Ara-C e Mesilato de eribulina). Com a rica biodiversidade brasileira e a grande necessidade mundial por tratamentos anticâncer mais eficazes e com menos efeitos colaterais, o objetivo deste estudo foi investigar o potencial de extratos obtidos de esponjas marinhas coletadas no Arquipélago de Fernando de Noronha, através da avaliação da atividade citotóxica dos extratos obtidos em células tumorais em cultura. No capítulo I realizou-se um estudo bioprospectivo. Para tanto, exemplares de 47 esponjas foram coletadas no ano de 1998 em diversos locais do Arquipélago, classificadas taxonomicamente e extraídas em solvente orgânico, dando origem aos respectivos extratos brutos. Destes, 39 extratos brutos foram submetidos à avaliação qualitativa de sua citotoxicidade em duas linhagens de células tumorais humanas em cultura: HCT116 (carcinoma colorretal) e MCF-7 (adenocarcinoma mamário) pelo ensaio de MTT. Os resultados obtidos através desta triagem selecionaram, para abordagem quantitativa, as amostras com porcentagem de ao menos 75% de inibição do crescimento celular na presença de concentrações de 5 e 50 μg/mL dos extratos. Dos 39 testados contra as células HCT-116, aproximadamente 46% mostraram-se ativos, enquanto por volta de 29% dos 34 testados demonstraram resultados promissores contra MCF-7. Entre os extratos ativos, o FN98-017 obtido da espécie Ectyoplasia ferox foi considerado promissor e selecionado para prosseguir em investigação, realizado no capítulo II deste estudo. Para tanto, foi realizado o fracionamento bioguiado deste extrato, identificando a partição But P e a fração F16 como as amostras mais citotóxicas. Estas amostras ainda se apresentaram citotóxicas contra linhagens tumorais de diversas origens histológicas. Mais além, foram submetidas à verificação dos respectivos efeitos sobre a viabilidade celular e quanto à indução de alterações morfológicas, buscando gerar evidências para aprofundar o conhecimento do modo de ação destas amostras. A partir destas análises, é possível sugerir que But P e F16 são capazes de disparar o processo de apoptose celular, logo, mostram-se promissoras para estudos mais aprofundados sobre os seus efeitos anticâncer.
- ItemSomente MetadadadosBiocompatibilidade e potencial osteogênico de scaffolds manufaturados a partir de esponjas marinhas(Universidade Federal de São Paulo (UNIFESP), 2019-03-29) Santos, Cintia Pereira De Goes [UNIFESP]; Granito, Renata Neves [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The marine sponges present interesting features, such as their three-dimensional architecture with interconnected pores, as well as their organic and inorganic components, which make them relevant candidates as biomaterials for the engineering of bone tissue. Therefore, this study aims to characterize and compare the in vivo osteogenic potential of scaffolds manufactured from two species of marine sponges, Dragmacidon reticulatum and Amphimedon viridis, both of Class Demospongiae. Initially, the marine sponges were collected, cut, lyophilized and sterilized to make the scaffolds. The scaffolds obtained were characterized by MEV, FTIR, XRD, EDS, besides the pH and mass degradation assay. Following, in vivo tests were performed using a scaffold implantation model in bone defect surgically created in rat tibiae. The animals were randomly divided into three groups: control group (GC), in which the bone defects were not filled with biomaterial, and the Dragmacidon reticulatum (GD) and Amphimedon viridis (GA) groups, in which the bone defects were filled with the scaffolds manufactured from the species Dragmacidon reticulatum and Amphimedon viridis, respectively. The animals were euthanized 15 days after surgery, the right tibias were used for biomechanical testing and the left tibia included in methyl methacrylate for histological and histomorphometric analysis of the non-decalcified bone tissue. In the characterization analyzes of the scaffolds, the SEM / EDS showed in both samples the presence of silica spurs, pores and the same chemical composition, the main elements being Si (silicon), O (oxygen) and C (carbon). There was a higher pore presence in a qualitative analysis, and a consequent greater degradation in the scaffolds of GD. pH analysis also revealed a greater variation in GD, with a more significant fall at the beginning of incubation (first three days). The XRD demonstrated the amorphous nature of scaffolds, with low crystallinity, for both species. The FTIR compared the functional groups and indicated a greater loss of organic matter in GD. In the histological analysis, the GC presented extensive formation of bone tissue at the edges of the lesion, with presence of osteoid tissue around it. The GD, when compared to GA, presented some points of neoformed bone tissue and a greater amount of osteoid tissue within the bone defect, always around the silica spicules. In turn, GA presented a fibrous capsule around the lesion, no formation of bone tissue, and a small amount of osteoid tissue at isolated sites within the defect. At the same time, in the histomorphometric analysis, GD presented a significantly higher percentage of osteoid tissue (OV / TV,%), as well as a significantly larger osteoblastic surface with respect to the bone surface (Ob.S / BS,%). In the biomechanical evaluation, there was no statistical difference between the studied species. Thus, the results suggest that the samples of the Dragmacidon reticulatum species, when compared to those of the species Amphimedon viridis, are potentially more suitable for the favoring of bone regeneration and, therefore, for use in tissue engineering.
- ItemSomente MetadadadosCaracterização 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.