Ultrasmall Manganese Ferrite Nanoparticles as Positive Contrast Agent for Magnetic Resonance Imaging

The Fe3O4 fluid synthesis by thermal decomposition method carried out in organic solvents with high boiling temperatures disposes a possibility of creating high-quality nanoparticles with uniform particle size and high degree of crystallization. In this paper, Fe3O4 fluid was prepared by thermal decomposition using poly (maleic anhydride-alt-1-octadecene) (PMAO) as a phase transfer ligand. The crystalline structure, morphology and magnetic property of the as-prepared samples were thoroughly characterized. The results demonstrated that the magnetic Fe3O4 nanomaterial was formed in liquid phase with spinel single phase structure, average size of 13-16 nm, and high saturation magnetization (up to 70 emu/g). Iron oxide (Fe3O4) nanoparticles coated with biocompatible poly (maleic anhydride-alt-1-octadecene) (PMAO) were synthesized for use as an MRI (magnetic resonance imaging) contrast agent. The spin-lattice (T1) and the spin-spin (T2) relaxation times of the nuclear spins (hydrogen protons) in aqueous solutions of various concentrations of coated ferrite nanoparticles were determined using a nuclear magnetic resonance (NMR) spectrometer. The MRI image was detected with higher contrast in comparison with that before injecting. By comparing with the MRI images taken in T1 weighted the T2 weighted images are clearer. The MRI images of a rabbit taken by the T2 weighted which shows that our coated ferrite nanoparticles can be used as a T2 MRI contrast agent.

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Human Aortic Endothelial Cell Labeling with Positive Contrast Gadolinium Oxide Nanoparticles for Cellular Magnetic Resonance Imaging at 7 Tesla

Molecular Imaging ◽

10.2310/7290.2011.00037 ◽

2012 ◽

Vol 11 (2) ◽

pp. 7290.2011.00037 ◽

Cited By ~ 6

Author(s):

Yasir Loai ◽

Nurus Sakib ◽

Rafal Janik ◽

Warren D. Foltz ◽

HL Cheng

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Contrast Agent ◽

Positive Contrast ◽

Gadolinium Oxide ◽

Cell Labeling ◽

7 Tesla ◽

Human Aortic Endothelial Cell ◽

Resonance Imaging ◽

Aortic Endothelial

Positive T1 contrast using gadolinium (Gd) contrast agents can potentially improve detection of labeled cells on magnetic resonance imaging (MRI). Recently, gadolinium oxide (Gd2O3) nanoparticles have shown promise as a sensitive T1 agent for cell labeling at clinical field strengths compared to conventional Gd chelates. The objective of this study was to investigate Gado CELLTrack, a commercially available Gd2O3 nanoparticle, for cell labeling and MRI at 7 T. Relaxivity measurements yielded r1 = 4.7 s−1 mM−1 and r2/ r1 = 6.2. Human aortic endothelial cells were labeled with Gd2O3 at various concentrations and underwent MRI from 1 to 7 days postlabeling. The magnetic resonance relaxation times T1 and T2 of labeled cell pellets were measured. Cellular contrast agent uptake was quantified by inductively coupled plasma–atomic emission spectroscopy, which showed very high uptake compared to conventional Gd compounds. MRI demonstrated significant positive T1 contrast and stable labeling on cells. Enhancement was optimal at low Gd concentrations, attained in the 0.02 to 0.1 mM incubation concentration range (corresponding cell uptake was 7.26 to 34.1 pg Gd/cell). Cell viability and proliferation were unaffected at the concentrations tested and up to at least 3 days postlabeling. Gd2O3 is a promising sensitive and stable positive contrast agent for cellular MRI at 7 T.

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Ultrasmall Manganese Ferrites as Multimodal Bioimaging Agents and Fenton/Haber-Weiss Catalysts

10.26434/chemrxiv.13299314 ◽

2020 ◽

Author(s):

Susana Carregal-Romero ◽

Ana Beatriz Miguel-Coello ◽

Lydia Martínez-Parra ◽

Yilian Fernández-Afonso ◽

Sandra Plaza ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Catalytic Properties ◽

Strong Dependence ◽

Ferrite Nanoparticles ◽

Manganese Ferrite ◽

Resonance Imaging ◽

Substantial Impact ◽

Mn Doping ◽

Wide Range

Ultrasmall manganese ferrite nanoparticles display interesting features in bioimaging and Fenton nanocatalysis. However, little is known about how to optimize these nanoparticles to achieve simultaneously the highest efficiency in both types of applications. Herein, we present a cost-efficient synthetic microwave method that enables manganese ferrite nanoparticles to be produced with excellent control in size, chemical composition and colloidal stability. We show how the reaction’s pH has a substantial impact on the Mn incorporation into the nanoparticles and the level of Mn doping can be finely tailored to a wide range (MnxFe3-xO4, 0.1 ≤ x ≤ 2.4). The magnetic relaxivities (1.6 ≤ r1 ≤ 10.6 mM-1s-1 and (7.5 ≤ r2 ≤ 29.9 mM-1s-1) and Fenton/Haber-Weiss catalytic properties measured for the differently doped nanoparticles show a strong dependence on the Mn content and, interestingly, on the synthetic reaction’s pH. Positive contrast in magnetic resonance imaging is favored by low Mn contents, while dual mode magnetic resonance imaging contrast and catalytic activity increases in nanoparticles with a high degree of Mn doping. We show that this is valid in solution, in a murine model and intracellularly respectively. Besides, this synthetic protocol allows core-radiolabeling for high-sensitive molecular imaging while maintaining relaxometric and catalytic properties. All of these results show the robust characteristics of these multifunctional manganese ferrite nanoparticles as theranostic agents.

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Ultrasmall Manganese Ferrites as Multimodal Bioimaging Agents and Fenton/Haber-Weiss Catalysts

10.26434/chemrxiv.13299314.v1 ◽

2020 ◽

Author(s):

Susana Carregal-Romero ◽

Ana Beatriz Miguel-Coello ◽

Lydia Martínez-Parra ◽

Yilian Fernández-Afonso ◽

Sandra Plaza ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Catalytic Properties ◽

Strong Dependence ◽

Ferrite Nanoparticles ◽

Manganese Ferrite ◽

Resonance Imaging ◽

Substantial Impact ◽

Mn Doping ◽

Wide Range

Ultrasmall manganese ferrite nanoparticles display interesting features in bioimaging and Fenton nanocatalysis. However, little is known about how to optimize these nanoparticles to achieve simultaneously the highest efficiency in both types of applications. Herein, we present a cost-efficient synthetic microwave method that enables manganese ferrite nanoparticles to be produced with excellent control in size, chemical composition and colloidal stability. We show how the reaction’s pH has a substantial impact on the Mn incorporation into the nanoparticles and the level of Mn doping can be finely tailored to a wide range (MnxFe3-xO4, 0.1 ≤ x ≤ 2.4). The magnetic relaxivities (1.6 ≤ r1 ≤ 10.6 mM-1s-1 and (7.5 ≤ r2 ≤ 29.9 mM-1s-1) and Fenton/Haber-Weiss catalytic properties measured for the differently doped nanoparticles show a strong dependence on the Mn content and, interestingly, on the synthetic reaction’s pH. Positive contrast in magnetic resonance imaging is favored by low Mn contents, while dual mode magnetic resonance imaging contrast and catalytic activity increases in nanoparticles with a high degree of Mn doping. We show that this is valid in solution, in a murine model and intracellularly respectively. Besides, this synthetic protocol allows core-radiolabeling for high-sensitive molecular imaging while maintaining relaxometric and catalytic properties. All of these results show the robust characteristics of these multifunctional manganese ferrite nanoparticles as theranostic agents.

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