Incorporation of magnetic nanoparticles and paramagnetic molecules into human red blood cells for use as proton relaxivity enhancers for blood pool magnetic resonance imaging

Mounir Ibrahim

    Research output: ThesisDoctoral Thesis

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    Abstract

    [Truncated abstract] Chelated gadolinium compounds and magnetic nanoparticles have been developed for use as magnetic resonance imaging (MRI) contrast agents. However, both chelated gadolinium compounds and magnetic particles are rapidly cleared from the blood stream, gadolinium via renal excretion and magnetic nanoparticles by the reticulo-endothelial system. In order to extend the lifetime of the contrast agents in the blood stream, we have encapsulated contrast agents within red blood cells (RBCs) as a potential strategy for slowing their clearance from the blood pool. A key strategy for loading RBCs with contrast agent is to incubate them in the presence of the contrast agents under hypo-osmolar conditions. Under these conditions the cells swell and holes open up in the cell membranes allowing particles to pass into or out from the cell. The RBCs can be re-sealed by bringing the osmolarity of the medium back up to physiological values. Human RBCs were loaded with magnetic nanoparticles and gadoteric acid by two different methods. The methods comprised either hypo-osmolar incubation or a hypo-osmolar pulse in the presence of gadoteric acid or magnetic nanoparticles. The efficacy of the resulting RBCs as contrast agents for MRI was assessed by measuring the cell specific longitudinal and transverse proton relaxivities in a magnetic field of magnitude 1.4T...
    Original languageEnglish
    QualificationDoctor of Philosophy
    Publication statusUnpublished - 2013

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    Magnetic resonance
    Protons
    Blood
    Cells
    Contrast Media
    Nanoparticles
    Imaging techniques
    Molecules
    Gadolinium compounds
    Acids
    Gadolinium
    Cell membranes
    Magnetic fields

    Cite this

    @phdthesis{63152af6940c4b09bb8a5289e644f308,
    title = "Incorporation of magnetic nanoparticles and paramagnetic molecules into human red blood cells for use as proton relaxivity enhancers for blood pool magnetic resonance imaging",
    abstract = "[Truncated abstract] Chelated gadolinium compounds and magnetic nanoparticles have been developed for use as magnetic resonance imaging (MRI) contrast agents. However, both chelated gadolinium compounds and magnetic particles are rapidly cleared from the blood stream, gadolinium via renal excretion and magnetic nanoparticles by the reticulo-endothelial system. In order to extend the lifetime of the contrast agents in the blood stream, we have encapsulated contrast agents within red blood cells (RBCs) as a potential strategy for slowing their clearance from the blood pool. A key strategy for loading RBCs with contrast agent is to incubate them in the presence of the contrast agents under hypo-osmolar conditions. Under these conditions the cells swell and holes open up in the cell membranes allowing particles to pass into or out from the cell. The RBCs can be re-sealed by bringing the osmolarity of the medium back up to physiological values. Human RBCs were loaded with magnetic nanoparticles and gadoteric acid by two different methods. The methods comprised either hypo-osmolar incubation or a hypo-osmolar pulse in the presence of gadoteric acid or magnetic nanoparticles. The efficacy of the resulting RBCs as contrast agents for MRI was assessed by measuring the cell specific longitudinal and transverse proton relaxivities in a magnetic field of magnitude 1.4T...",
    keywords = "Red blood cells (RBCs), Magnetic nanoparticles, Contrast agents, MRI, Proton relaxivities, TEM, Gadolinium",
    author = "Mounir Ibrahim",
    year = "2013",
    language = "English",

    }

    TY - THES

    T1 - Incorporation of magnetic nanoparticles and paramagnetic molecules into human red blood cells for use as proton relaxivity enhancers for blood pool magnetic resonance imaging

    AU - Ibrahim, Mounir

    PY - 2013

    Y1 - 2013

    N2 - [Truncated abstract] Chelated gadolinium compounds and magnetic nanoparticles have been developed for use as magnetic resonance imaging (MRI) contrast agents. However, both chelated gadolinium compounds and magnetic particles are rapidly cleared from the blood stream, gadolinium via renal excretion and magnetic nanoparticles by the reticulo-endothelial system. In order to extend the lifetime of the contrast agents in the blood stream, we have encapsulated contrast agents within red blood cells (RBCs) as a potential strategy for slowing their clearance from the blood pool. A key strategy for loading RBCs with contrast agent is to incubate them in the presence of the contrast agents under hypo-osmolar conditions. Under these conditions the cells swell and holes open up in the cell membranes allowing particles to pass into or out from the cell. The RBCs can be re-sealed by bringing the osmolarity of the medium back up to physiological values. Human RBCs were loaded with magnetic nanoparticles and gadoteric acid by two different methods. The methods comprised either hypo-osmolar incubation or a hypo-osmolar pulse in the presence of gadoteric acid or magnetic nanoparticles. The efficacy of the resulting RBCs as contrast agents for MRI was assessed by measuring the cell specific longitudinal and transverse proton relaxivities in a magnetic field of magnitude 1.4T...

    AB - [Truncated abstract] Chelated gadolinium compounds and magnetic nanoparticles have been developed for use as magnetic resonance imaging (MRI) contrast agents. However, both chelated gadolinium compounds and magnetic particles are rapidly cleared from the blood stream, gadolinium via renal excretion and magnetic nanoparticles by the reticulo-endothelial system. In order to extend the lifetime of the contrast agents in the blood stream, we have encapsulated contrast agents within red blood cells (RBCs) as a potential strategy for slowing their clearance from the blood pool. A key strategy for loading RBCs with contrast agent is to incubate them in the presence of the contrast agents under hypo-osmolar conditions. Under these conditions the cells swell and holes open up in the cell membranes allowing particles to pass into or out from the cell. The RBCs can be re-sealed by bringing the osmolarity of the medium back up to physiological values. Human RBCs were loaded with magnetic nanoparticles and gadoteric acid by two different methods. The methods comprised either hypo-osmolar incubation or a hypo-osmolar pulse in the presence of gadoteric acid or magnetic nanoparticles. The efficacy of the resulting RBCs as contrast agents for MRI was assessed by measuring the cell specific longitudinal and transverse proton relaxivities in a magnetic field of magnitude 1.4T...

    KW - Red blood cells (RBCs)

    KW - Magnetic nanoparticles

    KW - Contrast agents

    KW - MRI

    KW - Proton relaxivities

    KW - TEM

    KW - Gadolinium

    M3 - Doctoral Thesis

    ER -