Fibronectin targeting contrast agent
Example systems and methods enhance contrast in MRI images. To facilitate imaging of atherosclerotic plaques, arterial and venous, cardiac, and even tumor tissues and fibrosis, a fibrin-fibronectin complex or disease-related fibronectin specific MRI contrast agent (CLPD) has a specific binding affinity for fibronectin.
1. A compound according to formula I:
(P) x -(T) y -(ML) z I ,
where P is a peptide comprising peptide sequence SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3 that binds to fibronectin, T is a monomer that forms a dendrimer or an oligomer, L is a ligand that conjugates to the functional groups of the dendrimer or oligomer and complexes with a metal ion M, wherein x is a value within a range of 1 to 10, y is a value within a range of 1 to 63, and where z is a value within a range of 1 to 64, and a spacer between the dendrimer or oligomer and the peptide, or a pharmaceutically acceptable salt or ester thereof.
2. The compound of claim 1 , wherein the spacer is a polyethyleneglycol spacer.
3. The compound of claim 1 , where L is selected from the group consisting of ethylenediamine, diethylenetriaminepentaacetate (DTPA), 1,4,7,10-tetraazadodecanetetraacetate (DOTA), 1,4,7,10-tetraazadodecane-1,4,7-triacetate (DO3A), ethylenediaminetetraacetate (EDTA), 1,4,7,10-tetraazacyclotridecanetetraacetic acid (TRITA), 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid (TETA), 1,4,7,10-tetraazadodecanetetramethylacetate (DOTMA), 1,4,7,10-tetraazadodecane-1,4,7-trimethylacetate (DO3MA), N,N′,N″,N′″-tetraphosphonatomethyl-1,4,7,10-tetraazacyclododecane (DOTP), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis (methylene methylphosphonic acid) (DOTMP), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis (methylene phenylphosphonic acid) (DOTPP), 1,4,7-triazacyclononanetriacetic acid (NOTA), and N,N′-ethylenedi-L-cysteine.
4. The compound of claim 1 , where M is a metal ion selected from the group consisting of Gd +3 , Eu +3 , Tm +3 , Dy +3 , Yb +3 , Mn +2 , Fe +3 , 55 Co, 64 Cu, 64 Cu, 47 Sc, 66 Ga, 68 Ga, 90 Y, 97 Ru, 99m Tc, 111 In, 109 Pd, 153 Sm, 177 Lu, 186 Re, and 188 Re.
5. The compound of claim 1 , where M is a PET or SPECT imaging agent, where the agent comprises 55 Co, 64 Cu, 67 Cu, 47 Sc, 66 Ga, 68 Ga, 90 Y, 97 Ru, 99m Tc, 111 In, 109 Pd, 153 Sm, 177 Lu, 186 Re, or 188 Re coordinated to a chelating agent.
6. The compound of claim 1 , where M is an MRI agent, comprising a chelating agent and a metal ion selected from the group consisting of Gd +3 , Eu +3 , Tm +3 , Dy +3 , Yb +3 , Mn +2 , and Fe +3 ions.
7. The compound of claim 1 , where the compound is a pharmaceutically acceptable salt or ester.
8. A compound according to formula II or a pharmaceutically acceptable salt or ester thereof:
9. The compound of claim 8 , where the compound is a pharmaceutically acceptable salt or ester.
10. A compound according to formula III or a pharmaceutically acceptable salt or ester thereof:
11. The compound of claim 10 , where the compound is a pharmaceutically acceptable salt or ester.
12. A compound according to formula IV or a pharmaceutically acceptable salt or ester thereof:
13. The compound of claim 12 , where the compound is a pharmaceutically acceptable salt or ester.
14. A compound according to formula V or a pharmaceutically acceptable salt or ester thereof:
15. The compound of claim 14 , where the compound is a pharmaceutically acceptable salt or ester.
16. A method of imaging a tissue in a subject, comprising:
administering an effective amount of a polypeptide-based contrast agent to the subject;
allowing time for the contrast agent to reach the tissue; and
imaging the tissue that has been contacted by the poly-peptide-based contrast agent,
wherein the polypeptide-based contrast agent is a compound according to formula II,
17. The method of claim 16 , wherein the step of imaging the tissue uses a signal selected from the group consisting of an MR signal, a SPECT signal, a ICP-OES signal, a laser light scattering signal, and a PET signal.
18. The method of claim 16 , where the tissue comprises one or more glycoproteins selected from the group consisting of fibronectin, a fibrin-fibronectin complex, and oncofetal fibronectin.
19. A method imaging a tissue in a subject, comprising:
administering an effective amount of a polypeptide-based contrast agent to the subject;
allowing time for the contrast agent to reach the tissue; and
imaging the tissue that has been contacted by the poly-peptide-based contrast agent,
wherein the polypeptide-based contrast agent is a compound according to formula III,
20. The method of claim 19 , wherein the step of imaging the tissue uses a signal selected from the group consisting of an MR signal, a SPECT signal, a ICP-OES signal, a laser light scattering signal, and a PET signal.
21. The method of claim 19 , where the tissue comprises one or more glycoproteins selected from the group consisting of fibronectin, a fibrin-fibronectin complex, and oncofetal fibronectin.
22. A method of imaging tissue in a subject, comprising:
administering an effective amount of a polypeptide-based contrast agent to the subject;
allowing time for the contrast agent to reach the tissue; and
imaging the tissue that has been contacted by the poly-peptide-based contrast agent,
wherein the polypeptide-based contrast agent is a compound according to formula IV,
23. The method of claim 22 , wherein the step of imaging the tissue uses a signal selected from the group consisting of an MR signal, a SPECT signal, a ICP-OES signal, a laser light scattering signal, and a PET signal.
24. The method of claim 22 , where the tissue comprises one or more glycoproteins selected from the group consisting of fibronectin, a fibrin-fibronectin complex, and oncofetal fibronectin.
25. A method of imaging a tissue in a subject, comprising:
administering an effective amount of a polypeptide-based contrast agent to the subject;
allowing time for the contrast agent to reach the tissue; and
imaging the tissue that has been contacted by the poly-peptide-based contrast agent,
wherein the polypeptide-based contrast agent is a compound according to formula V,
26. The method of claim 25 , wherein the step of imaging the tissue uses a signal selected from the group consisting of an MR signal, a SPECT signal, a ICP-OES signal, a laser light scattering signal, and a PET signal.
27. The method of claim 25 , where the tissue comprises one or more glycoproteins selected from the group consisting of fibronectin, a fibrin-fibronectin complex, and oncofetal fibronectin.
28. The compound of claim 1 , wherein y has a value of 3 and z has a value of 4.