Methods for collagen imaging

1. A collagen binding peptide, wherein the collagen binding peptide comprises a cyclic peptide comprising the amino acid sequence:

(SEQ ID NO: 74)

Q-W-H-C-T-T-R-F-P-H-H-Y-C-L-Y-G;

wherein the peptide has a total length of 16 to 20 amino acids, and wherein one or more of the amino acids in the peptide is derivatized with a non-metallic radionuclide selected from the group consisting of 18 F, 123 I, 125 I, and 131 I.

2. A collagen binding peptide, wherein the collagen binding peptide comprises a cyclic peptide comprising the amino acid sequence:

(SEQ ID NO: 828)

C*-X1-X2-X3-X4-X5-X6-X7-X8-C*,

wherein:

C* is C or Pen in D or L form;

X1=T, A, K, V, I, S, Y, G, R, P, L, 3-NO2 Y, 4-Pal, 4-CO2H-F, 4-tBu-F, F(4-NH2), Y(Bn, 3-Cl), b-h-S, Y(3-I), or Aib, in D or L form;

X2=T, A, N, S, Y, R, V, I, K, D, G, b-h-G, Orn, or Dpr, in D or L form;

X3=R, A, S, L, Y, D, K, G, P, Aib, Y(3-Cl), I, Cha, Abu, F(4-F), Dopa, Tle, Cit, b-h-D, or K(Boc), in D or L form;

X4=F, Bip, F(4-CF3), 4-Pal, 1-Nal, F(4-NO2), Hfe, Bpa, F(4-CN), F(4-NH2), F(3,4-OMe), 2-Nal, Y(3-Cl), Aib, or b-h-E, in D or L form;

X5=P, P(3-OH), APro, Pip, N-Me-A, P(3-OH), Y(3-I), b-h-Y, or Aib, in D or L form;

X6=H, A, S, K, N, Y, T, D, R, W, P, Aib, or b-h-T, in D or L form;

X7=H, A, S, N, D, Y, W, Aib, Dpr, 2-Pal, 1-Nal, thien-W, W(5-OH), or b-h-W, in D or L form; and

X8=Y, A, R, T, V, H, D, S, P, 1-Nal, Bip, DOPA, H-Tyr, H-Tyr(Me), F(3-OMe), Y(3-Cl), Y(2,6-Me2), Dip, F(4-NH2), or Aib, in D or L form; and

wherein the peptide has a length of 10 to 20 amino acids, and wherein one or more of the amino acids in the peptide is derivatized with a non-metallic radionuclide selected from the group consisting of 18 F, 123 I, 125 I, and 131 I.

3. The collagen binding peptide of claim 2 , wherein the cyclic peptide comprises the amino acid sequence:

C-T-T-S-F-P-H-H-Y-C,

(SEQ ID NO: 817)

C-T-T-K-F-P-H-H-Y-C,

(SEQ ID NO: 818)

C-Y-T-Y-F-P-H-H-Y-C,

(SEQ ID NO: 819)

C-T-T-R-F-P-H-H-Y-C,

(SEQ ID NO: 820)

or

C-S-G-D-E-Y-T-W-H-C.

(SEQ ID NO: 821)

4. The collagen binding peptide of claim 2 , wherein the cyclic peptide comprises the amino acid sequence:

(SEQ ID NO: 829)

C*-X1-X2-X3-X4-X5-X6-X7-X8-C*-X9-X10-X11,

wherein:

X9, X10, and X11 are any amino acid; and

wherein the peptide has a length of 13 to 20 amino acids.

5. The collagen binding peptide of claim 4 , wherein:

X9=L, A, I, K, V, F, N, Y, P, Aib, Hse, Hfe, Bpa, 2-Nal, Y(3-Cl), Dip, or F(4-NH2), in D or L form;

X10=Y, A, F, E, Bpa, 2-Nal, Y(3-Cl), Dip, F(4-NH2), or Y(3-I), in D or L form; and

X11=G, E, Y, F, V, Bip, F(4-NH2), or Aib, in D or L form.

6. The collagen binding peptide of claim 4 , wherein the cyclic peptide comprises the amino acid sequence:

(SEQ ID NO: 832)

C*-X1-X2-X3-X4-X5-X6-X7-X8-C*-X9-X10-X11-X12,

wherein:

X11 is any amino acid;

X12 is any one or two amino acids; and

wherein the peptide has a length of 14 to 20 amino acids.

7. The collagen binding peptide of claim 6 , wherein:

X11=G, E, Y, F, V, Bip, F(4-NH2), or Aib, in D or L form; and

X12=K, KK, Peg K, PEG(1×O), 1,4-AMB, 1,3-AMB, 1,6-Hex, PEG, or GTE, in D or L form.

8. The collagen binding peptide of claim 2 , wherein the collagen binding peptide comprises a cyclic peptide comprising the amino acid sequence:

(SEQ ID NO: 830)

X14-X13-C*-X1-X2-X3-X4-X5-X6-X7-X8-C*,

wherein:

X13 and X14 are any amino acid;

C* is C or Pen, in D or L form; and

wherein the peptide has a length of 12 to 20 amino acids.

9. The collagen binding peptide of claim 8 , wherein:

X13=H, A, S, K, N, D, Y, T, P, or Aib, in D or L form; and

X14=W, A, Y, 1-Nal, 2-Nal, thien-W, Tic, or W(5-OH), in D or L form.

10. The collagen binding peptide of claim 8 , wherein the collagen binding peptide comprises a cyclic peptide comprising the amino acid sequence:

(SEQ ID NO: 834)

X16-X15-X14-X13-C*-X1-X2-X3-X4-X5-X6-X7-X8-C*,

wherein:

X15 and X16 comprise one to three amino acids; and

wherein the peptide has a length of 14 to 20 amino acids.

11. The collagen binding peptide of claim 10 , wherein:

X15=Q, G, A, D, S, P, K, GQ, K(G), K(Y.G), K(V.G), K(F.G), K(H.H), KK(K), Dpr, or Aib, in D or L form; and

X16=G, K, PP, GY, GV, GF, GH, GK(G), KK(K), Dpr, EAG, or PPG, in D or L form.

12. The collagen binding peptide of claim 11 , wherein:

X15=Q, D, or K(G); and

X16=G.

13. A collagen binding peptide, wherein the collagen binding peptide comprises a cyclic peptide comprising the amino acid sequence:

(SEQ ID NO: 831)

X1-X2-X3-C*-X4-T-X5-X6-P*-X7-H-X8-C-X9-X10-X11

wherein:

X1=any amino acid in L form;

X2=W or W*;

X3=H, A, K, or S;

X4=T, Y, G, K, or Y*;

X5=any amino acid in L form;

X6=F, Y, Y*;

X7=H, A, or Y;

X8=Y or Y*;

X9=L, V, L*, or Y*;

X10=Y, F, or Y*; and

X11=G, Y, Bip, or Y*;

wherein:

W* is 1-Nal, 2-Nal, Bpa, thien-W, W(5-OH), 7-aza-Trp, 1-methyl-Trp, 5-bromo-Tryp, 5-chloro-Tryp, 5-fluor-Trp, 7-methyl-trp, 6-methyl-Trp, 6-flouro-Trp, or 6-hydroxy-trp;

Y* is F(4-NH2), F(3,4-OMe2), F(3-OMe), F(4-CF3), F(4-CN), F(4-NO2), F(4-F), F(4-NO2), Hfe, 4-tBu-F, 4-CO2H-F, h-Tyr, h-Tyr(Me), Y(2,6-Me2), Y(3-Cl), Y(3-I), Y(Bn, 3-Cl), 2-substituted L-Tyr, 2,3-substituted-L-Tyr, 2,3,5-substituted-L-tyr, 2,5-substituted-L-Tyr, 2,6-substituted-L-Tyr, 2,3,5,6-substituted-L-Tyr, 3-substituted-L-Tyr, 3,5-substituted-L-Tyr, 2-substituted L-Phe, 2,3-substituted-L-Phe, 2,3,5-substituted-L-Phe, 2,5-substituted-L-Phe, 2,6-substituted-L-Phe, 2,3,5,6-substituted-L-Phe, 3-substituted-L-Phe, 3,5-substituted-L-Phe, L-2-pyridylalanine, L-3-pyridylalanine, or L-4-pyridylalanine;

L* is I, V, A, L, G, Tle, L-norvaline, L-norleucine, L-dehydroleucine, L-abu (2-aminobutyric acid), L-tert-leucine, beta-cyclohexyl-L-alanine, L-homoleucine, or L-homo-cyclohexylalanine;

C* is C or Pen;

P* is P, L-hydroxyproline, piperidine-2-carboxylic acid, or 4-hydroxypiperidine-2-carboxylic acid; and

wherein the peptide has a length of 16 to 20 amino acids, and wherein one or more of the amino acids in the peptide is derivatized with a non-metallic radionuclide selected from the group consisting of 18 F, 123 I, 125 I, and 131 I.

14. The collagen binding peptide of claim 13 , wherein:

X1=Q or K(G); and

X5=R, Y, L, D, or K.

15. The collagen binding peptide of any one of claims 1 , 2 , and 13 , wherein the non-metallic radionuclide is 18 F.

16. The collagen binding peptide of any one of claims 1 , 2 , and 13 , wherein at least one of the one or more derivatized amino acids is a derivatized tyrosine.

17. The collagen binding peptide of claim 16 , wherein the derivatized tyrosine is iodinated with 123 I, 125 I, or 131 I.

18. The collagen binding peptide of any one of claims 1 , 2 , and 13 , wherein the one or more amino acids are derivatized with a non-metallic radionuclide at the N-terminus, the C-terminus or at an amino acid side chain.