Carbon nanotubes have been used as scaffolds for tissue engineering. However, the identification of these nanomaterials disperses in biological solutions and their direct interaction with nerve cells is still controve...Carbon nanotubes have been used as scaffolds for tissue engineering. However, the identification of these nanomaterials disperses in biological solutions and their direct interaction with nerve cells is still controversial. The aim of this work is to characterize the topographic and ultra-structural distribution of the composite made of multi wall carbon nanotubes-polyvinylpyrrolidone (MWCNTs-PVP) deposited on the Helix aspersa neurons and over glass coverslip. Scanning Electron Microscopy (SEM) and Confocal Microscopy (CM) studies were done to analyze the properties of such MWCNTs-PVP composite. The cerebral ganglion of Helix aspersa was treated and incubated with MWCNTs-PVP, fixing it in paraformaldehyde at 4% and was observed with SEM and CM. Although the nanotubes were not labeled or stained with fluorescent compounds, the MWCNTs-PVP deposited on glass and on nerve cells, was observed by the confocal microscope in the reflection mode. In SEM studies, it was observed that MWCNTs-PVP was attached to the surface on neurons. Moreover, in CM studies, it was possible to observe that MWCNTs-PVP was attached to the neuronal membrane, crossing the cell membrane and getting into the cytoplasm. These results support the hypothesis that carbon nanotubes interact with the neuronal cell membrane and can be useful for neuronal tissue engineering. In addition, these results open new alternatives for toxicological studies, in order to elucidate the cytotoxicity of MWCNTs-PVP composite in neurons and other excitable cells.展开更多
In recent decades snail consumption has been increasing throughout Europe. The Heliciculture meets this need and gets snail farms, in order to get consistent production in the shortest possible time. The research prov...In recent decades snail consumption has been increasing throughout Europe. The Heliciculture meets this need and gets snail farms, in order to get consistent production in the shortest possible time. The research provided, has a main objective to establish the microbiota of Helix aspersa Müller, both from healthy animals, and individuals with gastrointestinal processes. The samples selected for the study were feces obtained from snails collected in both breeding farms as field snails. In the case, farm animals were selected apparently form healthy individuals and others were with signs of gastrointestinal process study. Aliquots of each sample were plated on a range of culture media and incubated under different conditions of temperature and respiration. From the results we can note that the healthy snails (farmed or free-living) have been isolated and identified mostly, as strains belonging to the genera Pediococcus, Lactobacillus and Lactococcus and five strains of yeasts of the genera Candida and Cryptococcus. Individuals suffering from gastrointestinal disturbances processes have been isolated in high proportion species of Klebsiella, Pantoea, Citrobacter and Enterobacter. The results obtained indicate that the snails with health problems reduce the presence of strains of Lactobacillus and Lactococcus in favor of increasing and/or establishing colonization by strains of Enterobacteriaceae.展开更多
文摘Carbon nanotubes have been used as scaffolds for tissue engineering. However, the identification of these nanomaterials disperses in biological solutions and their direct interaction with nerve cells is still controversial. The aim of this work is to characterize the topographic and ultra-structural distribution of the composite made of multi wall carbon nanotubes-polyvinylpyrrolidone (MWCNTs-PVP) deposited on the Helix aspersa neurons and over glass coverslip. Scanning Electron Microscopy (SEM) and Confocal Microscopy (CM) studies were done to analyze the properties of such MWCNTs-PVP composite. The cerebral ganglion of Helix aspersa was treated and incubated with MWCNTs-PVP, fixing it in paraformaldehyde at 4% and was observed with SEM and CM. Although the nanotubes were not labeled or stained with fluorescent compounds, the MWCNTs-PVP deposited on glass and on nerve cells, was observed by the confocal microscope in the reflection mode. In SEM studies, it was observed that MWCNTs-PVP was attached to the surface on neurons. Moreover, in CM studies, it was possible to observe that MWCNTs-PVP was attached to the neuronal membrane, crossing the cell membrane and getting into the cytoplasm. These results support the hypothesis that carbon nanotubes interact with the neuronal cell membrane and can be useful for neuronal tissue engineering. In addition, these results open new alternatives for toxicological studies, in order to elucidate the cytotoxicity of MWCNTs-PVP composite in neurons and other excitable cells.
文摘In recent decades snail consumption has been increasing throughout Europe. The Heliciculture meets this need and gets snail farms, in order to get consistent production in the shortest possible time. The research provided, has a main objective to establish the microbiota of Helix aspersa Müller, both from healthy animals, and individuals with gastrointestinal processes. The samples selected for the study were feces obtained from snails collected in both breeding farms as field snails. In the case, farm animals were selected apparently form healthy individuals and others were with signs of gastrointestinal process study. Aliquots of each sample were plated on a range of culture media and incubated under different conditions of temperature and respiration. From the results we can note that the healthy snails (farmed or free-living) have been isolated and identified mostly, as strains belonging to the genera Pediococcus, Lactobacillus and Lactococcus and five strains of yeasts of the genera Candida and Cryptococcus. Individuals suffering from gastrointestinal disturbances processes have been isolated in high proportion species of Klebsiella, Pantoea, Citrobacter and Enterobacter. The results obtained indicate that the snails with health problems reduce the presence of strains of Lactobacillus and Lactococcus in favor of increasing and/or establishing colonization by strains of Enterobacteriaceae.
