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Perovskite nanoparticles for MRI and fluorescence microscopy
Kačenka, Michal
of Master diploma thesis Michal Kačenka, Prague 2009 The aim if this thesis is preparation of novel fluorescent magnetic nanoparticles. Such particles are promising materials for biomedical research as dual labeling agents. Silica-coated particles of perovskite phase La0.75Sr0.25MnO3 (LSMO@SiO2) were previously described as a promising material for magnetically induced hyperthermia. Besides, the relaxometric studies of LSMO@SiO2 suspension revealed high values of relaxivity r2, related to the contrast quality in MRI, significantly exceeding that of widely used iron oxide nanoparticles. Binding fluorescent dye into silica layer of LSMO@SiO2 could provide dual probe with the possibility of fluorescence and magnetic resonance detection, suitable for bimodal cellular labeling. The nanoparticles were coated by two-step procedure including the use of mixture of N-1-(3- triethoxysilylpropyl)-N'-fluoresceinylthiourea and tetraethoxysilane in the first step leading to the fluorescent silica shell. The resulting particles exhibit low colloidal stability in water and, therefore, they were subsequently coated by secondary pure silica layer in the next step employing only tetraethoxysilane. The final product exhibits sufficient colloidal stability in water. The morphology and size were investigated by means of...
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Perovskite nanoparticles for MRI and fluorescence microscopy
Kačenka, Michal
of Master diploma thesis Michal Kačenka, Prague 2009 The aim if this thesis is preparation of novel fluorescent magnetic nanoparticles. Such particles are promising materials for biomedical research as dual labeling agents. Silica-coated particles of perovskite phase La0.75Sr0.25MnO3 (LSMO@SiO2) were previously described as a promising material for magnetically induced hyperthermia. Besides, the relaxometric studies of LSMO@SiO2 suspension revealed high values of relaxivity r2, related to the contrast quality in MRI, significantly exceeding that of widely used iron oxide nanoparticles. Binding fluorescent dye into silica layer of LSMO@SiO2 could provide dual probe with the possibility of fluorescence and magnetic resonance detection, suitable for bimodal cellular labeling. The nanoparticles were coated by two-step procedure including the use of mixture of N-1-(3- triethoxysilylpropyl)-N'-fluoresceinylthiourea and tetraethoxysilane in the first step leading to the fluorescent silica shell. The resulting particles exhibit low colloidal stability in water and, therefore, they were subsequently coated by secondary pure silica layer in the next step employing only tetraethoxysilane. The final product exhibits sufficient colloidal stability in water. The morphology and size were investigated by means of...
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