SYNTHESIS AND CHARACTERIZATIONS OF NANOSTRUCTURED MAGNETIC MATERIALS FOR MRI T1 CONTRAST AGENTS
type: CreativeWork
description: The synthesis of magnetic nanomaterials (Gd2O3, Mn-doped ZnS and iron oxide with different size and morphologies) for potential applications as MRI T1 contrast agents was studied. These nanoparticles were characterized by using TEM, XRD, FTIR, Zeta potential, DTA/TGA and XPS. (1) Gd2O3 nanoparticles were synthesized with three different morphologies. Four synthetic factors were investigated, i.e. temperature, time, solvent and surfactant. It was found that the degree of Gd2O3 crystallization was greatly influenced by temperature. Sphere shape was selected as the optimized structure to obtain the best paramagnetic performance. Yb:Er co-doped Gd2O3 nanospheres were then successfully synthesised using thermal decomposition method. They were equiaxed in shape, and exhibited T1 effect with r1=1.529s-1mM-1. (2) A facile method for fabricating Gd2O3 nanoclusters (GNCs) was demonstrated with enhanced T1 effect. It was found that such protection did not only allow the Gd2O3 to be applied in wide pH range, but also avoided further aggregation. A relationship was demonstrated to exist between Gd2O3 loading and r1 per single cluster. The GNCs possessed high r1 values (up to 7.948 s-1mM-1 [Gd]) and low r2/r1 (down to 1.04). For all of the Gd loadings, polymer nanogel platform materials provided higher longitudinal relaxivity than the monodispersed individual Gd2O3. Hence, the GNCs were shown to be more effective as contrast agents than Gd2O3 -based counterparts. In vitro test was performed with cell lines, and clear T1-weight images were obtained. Thus, the POMA-g-PEG assisted GNCs were demonstrated to be potentially useful for magnetic-assisted delivery systems. (3) Dual modal contrast agent was successfully synthesized based on Mn-doped ZnS nanoparticles on graphene oxide (ZMGO). The ZMGO nanocomposites with three different emission colors, namely, blue, white and red, were synthesized. The average sizes of the ZMGO nanocomposites were all below 130 nm range, which facilitated…
abstract: The synthesis of magnetic nanomaterials (Gd2O3, Mn-doped ZnS and iron oxide with different size and morphologies) for potential applications as MRI T1 contrast agents was studied. These nanoparticles were characterized by using TEM, XRD, FTIR, Zeta potential, DTA/TGA and XPS. (1) Gd2O3 nanoparticles were synthesized with three different morphologies. Four synthetic factors were investigated, i.e. temperature, time, solvent and surfactant. It was found that the degree of Gd2O3 crystallization was greatly influenced by temperature. Sphere shape was selected as the optimized structure to obtain the best paramagnetic performance. Yb:Er co-doped Gd2O3 nanospheres were then successfully synthesised using thermal decomposition method. They were equiaxed in shape, and exhibited T1 effect with r1=1.529s-1mM-1. (2) A facile method for fabricating Gd2O3 nanoclusters (GNCs) was demonstrated with enhanced T1 effect. It was found that such protection did not only allow the Gd2O3 to be applied in wide pH range, but also avoided further aggregation. A relationship was demonstrated to exist between Gd2O3 loading and r1 per single cluster. The GNCs possessed high r1 values (up to 7.948 s-1mM-1 [Gd]) and low r2/r1 (down to 1.04). For all of the Gd loadings, polymer nanogel platform materials provided higher longitudinal relaxivity than the monodispersed individual Gd2O3. Hence, the GNCs were shown to be more effective as contrast agents than Gd2O3 -based counterparts. In vitro test was performed with cell lines, and clear T1-weight images were obtained. Thus, the POMA-g-PEG assisted GNCs were demonstrated to be potentially useful for magnetic-assisted delivery systems. (3) Dual modal contrast agent was successfully synthesized based on Mn-doped ZnS nanoparticles on graphene oxide (ZMGO). The ZMGO nanocomposites with three different emission colors, namely, blue, white and red, were synthesized. The average sizes of the ZMGO nanocomposites were all below 130 nm range, which facilitated…
author: YUAN JIAQUAN
keywords: magnetic materials,MRI, nanomaterials, fluorescent cell imaging, T1 imaging, contrast agents
date published: 2013-03-27
date modified: 2026-07-24T03:31:13Z
provider: National University of Singapore
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: National University of Singapore