Contrast agents
The present invention relates generally to multimodal magnetic resonance imaging (MRI) contrast agents. In particular, the present invention provides a MRI contrast agent configured to manipulate both the longitudinal (T 1 ) and transverse (T 2 ) relaxation times of surrounding water proton spins.
1. A magnetic resonance contrast agent composition comprising one or more T 1 contrast agent portions, and one or more T 2 contrast agent portions, wherein said one or more T 1 contrast agent portions comprise a paramagnetic metal ion chelate, and wherein said one or more T 2 contrast agent portions comprise a cobalt ferrite nanoparticle coated with a SiO 2 shell.
2. The magnetic resonance contrast agent composition of claim 1 , further comprising one or more linker regions.
3. The magnetic resonance contrast agent composition of claim 1 , wherein said paramagnetic metal ion is Gd(III).
4. The magnetic resonance contrast agent composition of claim 2 , wherein said linker region is a cleavable linker region.
5. The magnetic resonance contrast agent composition of claim 4 , wherein said cleavable linker region comprises a peptide linker portion.
6. The magnetic resonance contrast agent composition of claim 5 , wherein said peptide linker portion comprises a MMP-7 peptide linker.
7. The magnetic resonance contrast agent composition of claim 2 , wherein said linker region connects one said T 1 contrast agent portion to one said T 2 contrast agent.
8. The magnetic resonance contrast agent composition of claim 2 , wherein a T 2 contrast agent portion is connected to more than one T 1 -relaxation contrast agent portions by multiple linkers.
9. The magnetic resonance contrast agent composition of claim 1 , wherein more than one T 2 contrast agent portions are connected to more than one T 1 contrast agent portions by multiple linkers.
10. The magnetic resonance contrast agent composition of claim 1 , further comprising an imaging tag.
11. The magnetic resonance contrast agent composition of claim 10 , wherein said imaging tag is and optical imaging tag.
12. The magnetic resonance contrast agent composition of claim 1 , further comprising a targeting moiety.
13. A pharmaceutical formulation comprising a contrast agent of claim 1 and a pharmaceutically acceptable carrier, wherein the formulation is suitable for administration as an imaging enhancing agent and the contrast agent is present in an amount sufficient to enhance a magnetic resonance image.
14. A method of generating an image of at least a part of a subject comprising administering the composition of claim 1 to a subject, and generating an image of at least a part of said subject to which said composition has distributed.