7 research outputs found
Implants of polyanionic collagen matrix in bone defects of ovariectomized rats
Get PDFIn recent years, there has been a great interest in the development of biomaterials that could be used in the repair of bone defects. Collagen matrix (CM) has the advantage that it can be modified chemically to improve its mechanical properties. The aim of the present study was to evaluate the effect of three-dimensional membranes of native or anionic (submitted to alkaline treatment for 48 or 96 h) collagen matrix on the consolidation of osteoporosis bone fractures resulting from the gonadal hormone alterations caused by ovariectomy in rats subjected to hormone replacement therapy. The animals received the implants 4 months after ovariectomy and were sacrificed 8 weeks after implantation of the membranes into 4-mm wide bone defects created in the distal third of the femur with a surgical bur. Macroscopic analysis revealed the absence of pathological alterations in the implanted areas, suggesting that the material was biocompatible. Microscopic analysis showed a lower amount of bone ingrowth in the areas receiving the native membrane compared to the bone defects filled with the anionic membranes. In ovariectomized animals receiving anionic membranes, a delay in bone regeneration was observed mainly in animals not subjected to hormone replacement therapy. We conclude that anionic membranes treated with alkaline solution for 48 and 96 h presented better results in terms of bone ingrowth1913411348sem informaçãosem informaçã
Morphological characterization of a human glioma cell l ine
Get PDFA human malignant continuous cell line, named NG97, was recently established in our laboratory. This cell line has been serially subcultured over 100 times in standard culture media presenting no sign of cell senescence. The NG97 cell line has a doubling time of about 24 h. Immunocytochemical analysis of glial markers demonstrated that cells are positive for glial fibrillary acidic protein (GFAP) and S-100 protein, and negative for vimentin. Under phase-contrast microscope, cultures of NG97 showed cells with variable morphological features, such as small rounded cells, fusiform cells (fibroblastic-like cells), and dendritic-like cells. However, at confluence just small rounded and fusiform cells can be observed. At scanning electron microscopy (SEM) small rounded cells showed heterogeneous microextentions, including blebs and filopodia. Dendritic-like cells were flat and presented extensive prolongations, making several contacts with small rounded cells, while fusiform cells presented their surfaces dominated by microvilli. We believe that the knowledge about NG97 cell line may be useful for a deeper understanding of biological and immunological characteristics of gliomas
<body> <font color="#009900"> <b>Cultura de osteoblastos sobre membranas de colágeno polianiônico: avaliação preliminar do potencial de indução da formação de tecido ósseo visando reparação tecidual</b></body>
No full textAtualmente, observa-se a alta de incidência de lesões provocadas por traumas e choques mecânicos causados por diferentes fatores, caracterizadas principalmente pelas fraturas ósseas. Desta maneira, existe um interesse no desenvolvimento de biomateriais que possam ser utilizados como implantes no do tecido ósseo, e que atuem como indutores do processo de reparação óssea. Matrizes extracelulares tridimensionais compostas de colágeno apresentam a vantagem de poder ser modificadas em suas propriedades mecânicas e fisiológicas por métodos fÃsicos ou quÃmicos, resultando em matrizes carregadas positivo ou negativamente. O presente trabalho visa avaliar a capacidade das membranas tridimensionais de colágeno polianiônico e nativo no processo de consolidação de fraturas com perda de massa óssea. Utilizamos osteoblastos cultivados sobre esses biomateriais antes do implante no crânio de ratos linhagem Rowett nude. Observamos que os osteoblastos cultivados sobre o colágeno polianiônico foram capazes de formar tecido semelhante ao ósseo nas membranas e preencher a área lesada nos implantes realizados nos animais. ConcluÃmos que as membranas de colágeno polianiônico são uma alternativa viável para a reconstrução tecidual e engenharia de tecidos.
Palavras chave: Colágeno polianiônico, regeneração tecidual, cultura de células, osteoblastos, tecido ósseo.
ABSTRACTAt present, There are a high of incidence of wounds promoted by traumas and mechanical shocks caused by different factors, characterized mainly by bone fractures. Of this way, exist an interest in the development of biomaterials that can be used as implants in bone tissue for bone repair. Three-dimensional extracellular matrices composed of collagen present the advantage of be able to will be modified in his physiological and mechanical estates by physical or chemical approaches, resulting in positive or negatively loaded matrices. The present work is going to evaluate the capacity of the three-dimensional membranes of native and polyanionic collagen in the fractures consolidation trial with loss of bone mass. We used osteoblasts cultured on those biomateriais before of its implants in the skull of Rowett nude lineage mice. We observe that the osteoblasts cultured on polyanionic collagen were capable to form a bone-like tissue structure in the membranes and fill the damaged area in implants carried out in animals. We conclude that the polyanionic collagen membranes are a viable alternative for the tissue reconstruction and engineering.
Key words: Polyanionic collagen, tissue regeneration, cell culture, osteoblasts, bone tissue</div
Implants of polyanionic collagen matrix in bone defects of ovariectomized rats
No full textIn recent years, there has been a great interest in the development of biomaterials that could be used in the repair of bone defects. Collagen matrix (CM) has the advantage that it can be modified chemically to improve its mechanical properties. The aim of the present study was to evaluate the effect of three-dimensional membranes of native or anionic (submitted to alkaline treatment for 48 or 96 h) collagen matrix on the consolidation of osteoporosis bone fractures resulting from the gonadal hormone alterations caused by ovariectomy in rats subjected to hormone replacement therapy. The animals received the implants 4 months after ovariectomy and were sacrificed 8 weeks after implantation of the membranes into 4-mm wide bone defects created in the distal third of the femur with a surgical bur. Macroscopic analysis revealed the absence of pathological alterations in the implanted areas, suggesting that the material was biocompatible. Microscopic analysis showed a lower amount of bone ingrowth in the areas receiving the native membrane compared to the bone defects filled with the anionic membranes. In ovariectomized animals receiving anionic membranes, a delay in bone regeneration was observed mainly in animals not subjected to hormone replacement therapy. We conclude that anionic membranes treated with alkaline solution for 48 and 96 h presented better results in terms of bone ingrowth
