Contrast agents

Abstract

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.

We claim: 
     
         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 paramagnetic nanoparticle. 
     
     
         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.