MRI CONTRAST AGENT INCLUDING T1 CONTRAST MATERIAL COATED ON SURFACE OF NANOPARTICLE SUPPORT
20210113717 · 2021-04-22
Assignee
Inventors
Cpc classification
A61K49/1878
HUMAN NECESSITIES
International classification
A61K49/18
HUMAN NECESSITIES
Abstract
A magnetic resonance imaging (MRI) T1 contrast agent composition including T1 contrast material coated on the surface of a nanoparticle support and an imaging method using the MRI T1 contrast agent. The MRI T1 contrast agent composition has excellent T1 spin magnetic relaxation effects by modifying the paramagnetic T1 contrast material on the nanoparticle support having a certain diameter such that the paramagnetic T1 contrast material has a certain thickness or less, and thereby remarkably increasing the surface-to-volume ratio of the T1 contrast material. The MRI T1 contrast agent provides more precise and clear T1 positive contrast images, and is thus useful for highly reliable image diagnosis.
Claims
1. A magnetic resonance imaging (MRI) method, comprising (a) introducing an MRI T1 contrast agent, which produces a bright or positive contrast effect compared to water, into a body fluid, wherein the MRI T1 contrast agent consists of a non-magnetic nanoparticle support; and an iron oxide coating layer or an iron chelate coating layer coated directly on a surface of the non-magnetic nanoparticle support, wherein the non-magnetic nanoparticle support consists of SiO.sub.2, a polysaccharide, or a protein, and wherein a ratio of a thickness of the iron oxide coating layer or iron chelate coating layer to a diameter of the non-magnetic nanoparticle support is adjusted to 1:25 to 1:2.5; the diameter of the non-magnetic nanoparticle support is adjusted to 2 to 40 nm; and the thickness of the iron oxide coating layer or iron chelate coating layer is adjusted to 0.1 to 5 nm, to effectively cause the spin-lattice T1 relaxation of hydrogen nuclear spins in water molecules; and (b) obtaining bright or positive contrast images generated by the MRI T1 contrast agent present in the body fluid, as an information on body parts.
2. The MRI method of claim 1, further comprising (c) using the bright or positive contrast images obtained from the step (b) as imaging information for medical diagnosis.
3. The MRI method of claim 1, wherein the body parts are blood vessels.
4. The MRI method of claim 1, wherein the information on body parts is the presence or absence of bleeding in a lesion.
5. The MRI method of claim 1, wherein the polysaccharide is a dextran.
6. The MRI method of claim 1, wherein the ratio of the thickness of the iron oxide coating layer or iron chelate coating layer to the diameter of the non-magnetic nanoparticle support is adjusted to 1:25 to 1:10.
7. The MRI method of claim 1, wherein the ratio of the thickness of the iron oxide coating layer or iron chelate coating layer to the diameter of the non-magnetic nanoparticle support is adjusted to 1:25.
8. The MRI method of claim 1, wherein the MRI T1 contrast agent is prepared by the method of claim 9.
9. A method of synthesizing a magnetic resonance imaging (MRI) T1 contrast agent, which produce a bright or positive contrast effect compared to water and thus allow to obtain bright or positive contrast images generated by the MRI T1 contrast agent present in the body fluid, as an information on body parts, (1) preparing a non-magnetic nanoparticle support, consisting of SiO.sub.2, a polysaccharide, or a protein, the diameter of which is 2 to 40 nm; and (2) forming the iron oxide coating layer or an iron chelate coating layer on a surface of the non-magnetic nanoparticle support by a reaction at room temperature in an aqueous colloidal solution in which the non-magnetic nanoparticle support is dispersed, while adjusting (i) the ratio of the thickness of the iron oxide coating layer or iron chelate coating layer to the diameter of the non-magnetic nanoparticle support to 1:25 to 1:2.5; and (ii) the thickness of the iron oxide coating layer or iron chelate coating layer to 0.1 to 5 nm, to effectively cause the spin-lattice T1 relaxation of hydrogen nuclear spins in water molecules.
10. The synthesizing method of claim 9, wherein the MRI T1 contrast agent generates imaging information for medical diagnosis, by obtaining bright or positive contrast images generated by the MRI T1 contrast agent present in the body fluid.
11. The synthesizing method of claim 9, wherein the body parts are blood vessels.
12. The synthesizing method of claim 9, wherein the information on body parts is the presence or absence of bleeding in a lesion.
13. The synthesizing method of claim 9, wherein the polysaccharide is a dextran.
14. The synthesizing method of claim 9, wherein the ratio of the thickness of the iron oxide coating layer or iron chelate coating layer to the diameter of the non-magnetic nanoparticle support is adjusted to 1:25 to 1:10.
15. The synthesizing method of claim 9, wherein the ratio of the thickness of the iron oxide coating layer or iron chelate coating layer to the diameter of the non-magnetic nanoparticle support is adjusted to 1:25.
16. The synthesizing method of claim 9, wherein the non-magnetic nanoparticle support of the MRI T1 contrast agent is a water-soluble multifunctional ligand.
17. The synthesizing method of claim 16, wherein the water-soluble multifunctional ligand is a dextran.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0069]
[0070]
MODE FOR CARRYING OUT THE INVENTION
[0071] Hereinafter, the present invention will be described in detail with reference to examples. These examples are only for illustrating the present invention more specifically, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples.
EXAMPLES
Example 1
Synthesis of Silica Nanoparticle Support
[0072] Ammonium hydroxide (Sigma-Aldrich, USA) was added to a cyclohexane (Fluka, USA) solution containing IGAPAL CO-520™ (Sigma-Aldrich, USA) to form reverse micelles, and then tetraethoxysilane (Sigma-Aldrich, USA) as a silica precursor was added. The mixture was allowed react at room temperature for 24 hours to synthesize spherical-shaped silica nanoparticles. The thus formed silica nanoparticles were precipitated and separated by centrifugation after the addition of an excessive amount of ethanol. After the separated nanoparticles were re-dispersed in an excessive amount of acetone, extra reactant materials were removed through centrifugation, and finally, the nanoparticles were dispersed in water.
Example 2
Synthesis of 25 nm-sized silica nanoparticle support (SiO.SUB.2.)
[0073] A 15% aqueous ammonium hydroxide solution (2.31 mL) was added to a cyclohexane (69.5 g) solution containing IGAPAL CO-520™ (7.45 g) to form reverse micelles, and then tetraethoxysilane (0.25 mL) as a silica precursor was added. The mixture was allowed react at room temperature for 24 hours to synthesize spherical-shaped silica nanoparticles. The silica nanoparticles synthesized by the above method has a size of 25 nm. The thus formed silica nanoparticles were precipitated and separated by centrifugation after the addition of an excessive amount of ethanol. The separated nanoparticles were re-dispersed in an excessive amount of acetone, and extra reactant materials were removed through centrifugation. Finally, the nanoparticles were dispersed in water, and then purified by several filtrations using a filter (ULTRACONEm, Millipore, USA).
Example 3
Size Adjustment of Silica Nanoparticle Support (SiO.SUB.2.)
[0074] An aqueous ammonium hydroxide solution (2.31 mL) was added to a cyclohexane (69.5 g) solution containing IGAPAL CO-520™ (7.45 g) to form reverse micelles, and then tetraethoxysilane (0.25 mL) as a silica precursor was added.
[0075] Here, 20 nm-, 30 nm-, 40 nm-, and 45 nm-sized silica nanoparticles were, respectively, synthesized by adjusting the concentration of the aqueous ammonium hydroxide solution. The formed silica nanoparticles were precipitated and separated by centrifugation after the addition of an excessive amount of ethanol. The separated nanoparticles were re-dispersed in an excessive amount of acetone, and extra reactant materials were removed through centrifugation. Finally, the nanoparticles were dispersed in water, and then purified by several filtrations using a filter (ULTRACONE™, Millipore, USA).
Example 4
Synthesis of Dextran Nanoparticle Support
[0076] Sodium hydroxide (Sigma-Aldrich, USA) and epichlorohydrin (Sigma-Aldrich, USA) were added to an aqueous dextran (Pharmacosmos, Denmark) solution, thereby substituting a hydroxy group of dextran with an epoxide group. Ethylene diamine was added to cross-link dextran chains, thereby synthesizing dextran nanoparticles. The thus synthesized dextran nanoparticles were precipitated and separated by centrifugation after the addition of an excessive amount of ethanol. The separated dextran nanoparticles were re-dispersed in water and then extra reactant materials were removed through a dialysis filter (Spectrum Labs., USA).
Example 5
Size Adjustment of Dextran Nanoparticle Support
[0077] Sodium hydroxide (5 N) and epichlorohydrin (6 mL) were added to an aqueous solution (9 mL) containing dextran (1.8 g), thereby substituting a hydroxy group of dextran with an epoxide group. Ethylene diamine (26 mL) was added in a droplet type to cross-link dextran chains, thereby synthesizing dextran nanoparticles. Here, 3 nm-, 5 nm-, 7 nm-, and 12 nm-sized dextran nanoparticles can be synthesized by regulating the rate of ethylene diamine, respectively. The thus synthesized dextran nanoparticles were precipitated and separated by centrifugation after the addition of an excessive amount of ethanol. The separated dextran nanoparticles were re-dispersed in water and then extra reactant materials were removed through a dialysis filter (Spectrum Labs., USA).
Example 6
Preparation of Nano-Sized Protein Support
[0078] Protein has a characteristic size and shape depending on the kind and molecular weight thereof. According to the literature (H. P. Erickson et al. Biol. Proced. Online 2009, 11, 32.), the size of the protein is proportional to the ⅓ square of the molecular weight of the protein, and specifically, a relationship is provided by R=0.066M.sup.1/3. Two kinds of proteins (aprotinin and lysozyme) having different molecular weights, to be used as supports, were prepared. Aprotinin (Sigma-Aldrich, USA) and lysozyme (Sigma-Aldrich, USA), which are proteins having molecular weights of 6.7 kDa and 14.3 kDa, respectively, have sizes of 1.2 nm and 1.63 nm, respectively.
Example 7
Synthesis of Nanoparticles including Manganese Oxide Coated on Silica Nanoparticle Support
[0079] In order to coat a manganese oxide on surfaces of the foregoing synthesized spherical-shaped silica nanoparticles, the following method was conducted. An aqueous colloidal solution, in which silica nanoparticles were dispersed, and Mn(OAc).sub.2 (Sigma-Aldrich, USA), as precursors, were added to an excessive amount of diethylene glycol (Duksan, Korea), followed by a reaction at 90° C. for 12 hours, thereby synthesizing spherical-shaped nanoparticles including a manganese oxide coated on the silica nanoparticle support. In order to remove extra reactant materials, an excessive amount of acetone was added to the synthesized nanoparticles, a centrifugation procedure was repeated several times, and then the nanoparticles was dispersed in water.
Example 8
Surface Modification using Water-Soluble Multi-Functional Group Ligands of Nanoparticles (SiO.SUB.2.@Mn.SUB.3.O.SUB.4.) including Manganese Oxide Coated on Silica Nanoparticle Support
[0080] In order to increase stability of the nanoparticles including a manganese oxide coated on silica nanoparticles, synthesized in example 7, in the aqueous solution, a surface modification was performed using dextran, which is one of the aqueous multi-functional group ligands. The surface modification was performed by adding the nanoparticles (10 mg) to distilled water (10 ml) containing dextran (2.25 g) and then performing a reaction at 75° C. for 12 hours. The surface modification was achieved through a metal-ligand coordination bond between manganese of the nanoparticle surface manganese oxide and the hydroxy group of dextran. The nanoparticles upon the completion of the surface modification were purified by removing extra dextran through several filtrations using a filter (UltraCone, Millipore, USA).
Example 9
Synthesis of Nanoparticles including Manganese Oxide Coated on Silica Nanoparticle support
[0081] In order to coat an iron oxide on the surface of the previously synthesized nanoparticle support (silica, dextran, protein), the following method was performed. FeCl.sub.3.6H.sub.2O (Sigma-Aldrich, USA) and FeCl.sub.2.4H.sub.2O (Sigma-Aldrich, USA) as precursors were added to an aqueous colloidal solution in which nanoparticles were dispersed, followed by stirring. After that, ammonium hydroxide was added, followed by a reaction at room temperature for 10 minutes, thereby synthesizing nanoparticles including an iron oxide coated on the nanoparticle support. Extra iron oxide nanoparticles that were not coated on the support were removed by repeating centrifugation, and then purification was performed using a filter (ULTRACONEm, Millipore, USA) to remove extra reactant materials.
Example 10
Verification on Relationship between Surface-to-Volume Ratio of Mn.SUB.3.O.SUB.4 .and Magnetic Spin Relaxation Effect after Comparison of Magnetic Spin Relaxation Effect Depending on the Thickness of Mn.SUB.3.O.SUB.4.; Coating in SiO.SUB.2.@Mn.SUB.3.O.SUB.4 .Nanoparticles
[0082] Spherical nanoparticles, which have different thicknesses of Mn.sub.3O.sub.4 but the same composition of SiO.sub.2@Mn.sub.3O.sub.4, were synthesized, and then the T1 magnetic spin relaxation effect (SiO.sub.2@Mn.sub.3O.sub.4) was measured using a magnetic resonance imaging (MRI) scanner. In order to observe the effect depending on the thickness of Mn.sub.3O.sub.4, the other experiment conditions were the same. The specific experiment method was as follows. Each sample was dispersed in water to have concentrations of 0.25 mM, 0.125 mM, and 0.0625 mM (based on manganese), putted in the PCR tube, and then fixed to the support. Subsequently, the support was positioned at the center of the MRI wrist coil (Philips, Netherlands), and then, the Ti relaxation time for each sample was measured using an MRI scanner (15 T Philips, Netherlands). After that, in order to calculate an accurate concentration of each sample, the amount of manganese ions was quantified through ICP-AES assay. Based on this, the T1 magnetic spin relaxation effect ((r1)) was obtained. The T1 magnetic spin relaxation effect (r1, mM.sup.−1s.sup.−1) may be obtained by a slope when the reverse (s.sup.−1) of the T1 relaxation time was plotted with respect to the concentration of manganese ions (mM). The thus obtained values were shown in
Example 11
Verification on Relationship between Nanoparticle Support Diameter and Magnetic Spin Relaxation Effect
[0083] An iron oxide was coated on nanoparticle supports having different sizes under the same conditions, and then the T1 magnetic spin relaxation effects (r1) of nanomaterials were measured using a magnetic resonance imaging (MRI) scanner. The nanoparticle supports used in the present experiment were protein (1.2 nm, 1.63 nm), dextran (3.02 nm, 4.78 nm, 6.83 nm, 11.6 nm), and silica (19.26 nm, 33.29 nm, 38.84 nm, 44.89 nm). A specific experiment method was as follows. Each sample was dispersed in water to have concentrations of 0.25 mM, 0.125 mM, and 0.0625 mM (based on iron), putted in the PCR tube, and then fixed to the support. Subsequently, the support was positioned at the center of the MRI wrist coil (Philips, Netherlands), and then the Ti relaxation time for each sample was measured using an MRI scanner (15 T Philips, Netherlands). Based on the measured T1 value and the iron concentration of each sample, the T1 magnetic spin relaxation effect (r1) were obtained. T1 magnetic spin relaxation effect (r1, mM.sup.−1s.sup.−1) may be obtained by a slope when the reverse (s.sup.−1) of T1 relaxation time was plotted with respect to the concentration of manganese ions (mM). The thus obtained values are shown in
[0084] Although the present invention has been described in detail with reference to the specific features, it will be apparent to those skilled in the art that this description is only for a preferred embodiment and does not limit the scope of the present invention. Thus, the substantial scope of the present invention will be defined by the appended claims and equivalents thereof.