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- ItemSomente MetadadadosCalcium phosphate fibers coated with collagen: in vivo evaluation of the effects on bone repair(Cadernos Saude Publica, 2016) Ueno, Fabio Roberto [UNIFESP]; Kido, Hueliton Wilian [UNIFESP]; Granito, Renata Neves [UNIFESP]; Gabbai-Armelin, Paulo Roberto [UNIFESP]; Magri, Angela Maria Paiva [UNIFESP]; Fernandes, Kelly Rossetti [UNIFESP]; Silva, Antonio Carlos da; Braga, Francisco José Correa; Renno, Ana Claudia Muniz [UNIFESP]The aim of this study was to assess the characteristics of the CaP/Col composites, in powder and fiber form, via scanning electron microscopy (SEM), pH and calcium release evaluation after immersion in SBF and to evaluate the performance of these materials on the bone repair process in a tibial bone defect model. For this, four different formulations (CaP powder -CaPp, CaP powder with collagen -CaPp/Col, CaP fibers - CaPf and CaP fibers with collagen - CaPf/Col) were developed. SEM images indicated that both material forms were successfully coated with collagen and that CaPp and CaPf presented HCA precursor crystals on their surface. Although presenting different forms, FTIR analysis indicated that CaPp and CaPf maintained the characteristic peaks for this class of material. Additionally, the calcium assay study demonstrated a higher Ca uptake for CaPp compared to CaPf for up to 5 days. Furthermore, pH measurements revealed that the collagen coating prevented the acidification of the medium, leading to higher pH values for CaPp/Col and CaPf/Col. The histological analysis showed that CaPf/Col demonstrated a higher amount of newly formed bone in the region of the defect and a reduced presence of material. In summary, the results indicated that the fibrous CaP enriched with the organic part (collagen) glassy scaffold presented good degradability and bone-forming properties and also supported Runx2 and RANKL expression. These results show that the present CaP/Col fibrous composite may be used as a bone graft for inducing bone repair.
- ItemAcesso aberto (Open Access)Desenvolvimento de um protótipo para geração de nano e microfibras: rotofiador(Universidade Federal de São Paulo, 2022-01-31) Ramos, Suzane Cristina de Lima [UNIFESP]; Soares, Vitória de Oliveira [UNIFESP]; Concha, Viktor Oswaldo Cárdenas [UNIFESP]; Soares, Vitória; http://lattes.cnpq.br/0661599261187131Atualmente a geração de fibras em escala micrométrica e nanométrica tem ganhado destaque devido a inúmeras aplicações destes materiais principalmente na área biomédica, por apresentarem alta capacidade mimética, como por exemplo, os scaffolds, estruturas utilizadas na engenharia de tecidos. Dentre as técnicas utilizadas para a geração destas fibras temos: fiação, eletrofiação, impressão 3D e rotofiação. A rotofiação é uma técnica simples, de baixo custo e que apresenta maior taxa de produção quando comparada às demais. Sendo assim, este trabalho tem por objetivo a construção de um protótipo, além de explorar os principais aspectos tais como: conceito, tipos de configurações, parâmetros que influenciam a geração das fibras e aplicações. A montagem do protótipo será baseada em conceitos e equipamentos existentes no mercado. O rotofiador apresenta a seguinte configuração: copo oco (deposição da solução polimérica), motor e sistema coletor de fibras. Através deste trabalho espera-se obter um equipamento versátil e de fácil manuseio, permitindo a obtenção de micro ou nanofibras a partir de biopolímero. Cabe ressaltar que não existe este equipamento para compra no mercado e pesquisa realizada para sua construção com fornecedor verificou-se que o preço fica em torno de 15 mil reais. Com isso, através deste estudo verificou-se que é possível a construção de um rotofiador de baixo custo, podendo ficar em torno de 2 mil reais.
- ItemSomente MetadadadosEfeito de diferentes formas de fosfato de cálcio no processo de reparo ósseo em tibia de ratos(Universidade Federal de São Paulo (UNIFESP), 2016-01-04) Ueno, Fabio Roberto [UNIFESP]; Renno, Ana Claudia Muniz [UNIFESP]; http://lattes.cnpq.br/4106611304688552; Universidade Federal de São Paulo (UNIFESP)Autograft has been widely used because has shown an osteogenic potential and is immunological inert. Nevertheless, there are restriction on this kind of graft, morbity of the donor site, infection and restrict donor areas. Hence, synthetic biomaterials have be developed as an alternative to substitute the autograft stimulus. Among several biomaterials calcium phosphate (CaP) one of the most rechearched ceramic to improve bone consolidation because it have a singular composition and a high osteogenic potential. Associate with collagen, (CaP/Col) mimic the bone content, an inorganic part (CaP) and an organic part (collagen I). Ninity percent of the organic components in the bone are collagen; therefore, this composite (CaP/Col) shoud it show a high performance. Furthermore, form is another important issue to a biomaterial graft, powder and porous scaffolds have broadly studies showing that this material can enhance cellular adhesion and angiogenesis. However, on most cases it cannot be apply on irregular bone defect. Thus, a fiber form material can be useful in an irregular bone fracture, inasmuch as the fiber form have a profitable malleability. In this context, the hypothesis of this study was that the fibers form coated with collagen showed a superior new bone formation on rats? tibial bone. Therefore, the aim of this study was to assess the characteristics of the CaPp/Col composites CaP and CaPf/C,CaPf. To be evaluating, in vitro phisical quimical characteristics as SEM, calcium Assay, pH mensuration, FT-IR and in vivo, inflammatory infiltrate, granulation tissue, new bone formation, histomorphometric and ostegenic immunomarkers (Runx 2 and RANK-L).
- ItemSomente MetadadadosOsteoconductive properties of two different bioactive glass forms (powder and fiber) combined with collagen(Elsevier Science Bv, 2017) Magri, Angela Maria Paiva [UNIFESP]; Fernandes, Kelly Rossetti [UNIFESP]; Ueno, Fabio Roberto [UNIFESP]; Kido, Hueliton Wilian [UNIFESP]; Silva, Antonio Carlos da; Braga, Francisco José Correa; Granito, Renata Neves [UNIFESP]; Gabbai-Armelin, Paulo Roberto [UNIFESP]; Renno, Ana Claudia Muniz [UNIFESP]Bioactive Glasses (BG) is a group of synthetic silica-based materials with the unique ability to bond to living bone and can be used in bone repair. Although the osteogenic potential of BG, this material may have not present sufficient osteoconductive and osteoinductive properties to allow bone regeneration, especially in compromised situations. In order to overcome this limitation, it was proposed the combination the BG in two forms (powder and fiber) combined with collagen type I (COL-1). The aim of this study was to evaluate the BG/COL-based materials in terms of morphological characteristics, physicochemical features and mineralization. Additionally, the second objective was to investigate and compare the osteoconductive properties of two different bioactive glass forms (powder and fiber) enriched or not with collagen using a tibial bone defect model in rats. For this, four different formulations (BG powder -BGp, BG powder enriched with collagen - BGp/Col, BG fibers - BGf and BGp fibers enriched with collagen - BGf/Col) were developed. The physicochemical and morphological modifications were analyzed by SEM, FTIR, calcium assay and pH measurement. For in vivo evaluations, histopathology, morphometrical and immunohistochemistry were performed in a tibial defect in rats. The FTIR analysis indicated that BGp and BGf maintained the characteristic peaks for this class of material. Furthermore, the calcium assay showed an increased Ca uptake in the BG fibers. The pH measurements revealed that BGp (with or without collagen) presented higher pH values compared to BGf. In addition, the histological analysis demonstrated no inflammation for all groups at the site of the injury, besides a faster material degradation and higher bone ingrowth for groups with collagen. The immunohistochemistry analysis demonstrated Runx-2 and Rank-L expression for all the groups. Those findings support that BGp with collagen can be a promising alternative for treating fracture of difficult consolidation. (C) 2017 Elsevier B.V. All rights reserved.