RNA aptamers and methods for identifying the same

1. A RNA aptamer that binds to the coagulation pathway factor prothrombin or thrombin, the RNA aptamer comprising, in a 5′ to 3′ direction, a first stem region, a first loop region comprising a consensus sequence, the consensus sequence comprising AACAA, a second stem region, a second loop region, and a third loop region.

2. The aptamer of claim 1 wherein the aptamer is at least 80% homologous to a nucleotide sequence selected from the group consisting of SEQ ID NOs: 50-57, and truncates thereof.

3. The aptamer of claim 1 comprising nucleotide sequences selected from the group consisting of SEQ ID NOs: 50-53, 55-57, and truncates thereof.

4. The aptamer of claim 1 , wherein the aptamer binds coagulation pathway factor prothrombin.

5. The aptamer of claim 1 , wherein the aptamer binds coagulation pathway factor thrombin.

6. The aptamer of claim 1 , having a dissociation constant of about 100 picomolar (pM) to about 10 nanomolar (nM) or less.

7. The aptamer of claim 1 , wherein the aptamer comprises at least one 2′-modified nucleotide.

8. The aptamer of claim 7 wherein the 2′-modified nucleotide is selected from the group consisting of a 2′-halo-modified nucleotide, a 2′-fluoro-modified nucleotide, and a 2′-O-alkyl-modified nucleotide.

9. The aptamer of claim 7 comprising at least one 2′-fluorocytidine or one 2′-fluorouridine.

10. The aptamer of claim 7 , wherein all cytidines are 2′-deoxy-2′-fluorocytidine, or all uridines are 2′-deoxy-2′-fluorouridine.

11. The aptamer of claim 7 comprising at least one 2′-O-alkyl-modified nucleotide.

12. The aptamer of claim 1 , wherein the aptamer comprises about 15 to 100 bases.

13. The aptamer of claim 1 , wherein the aptamer further comprises a covalently linked carrier selected from the group consisting of a soluble polymer, a biodegradable polymer, polyethylene glycol, and cholesterol.

14. A pharmaceutical composition comprising a therapeutically effective amount of an RNA aptamer which binds to the coagulation pathway factor prothrombin or thrombin, the RNA aptamer comprising, in a 5′ to 3′ direction a first stem region, a first loop region comprising a consensus sequence, the consensus sequence comprising AACAA, a second stem region, a second loop region and a third loop region.

15. The composition of claim 14 wherein the aptamer binds coagulation pathway factor prothrombin.

16. The composition of claim 14 wherein the aptamer binds coagulation pathway factor thrombin.

17. The composition of claim 14 wherein the aptamer comprises a nucleotide sequence selected from the group consisting of SEQ ID NOs: 50-53, 55-57, and truncates thereof.

18. The composition of claim 14 , wherein the aptamer comprises a sequence at least 80% homologous to a nucleotide sequence selected from the group consisting of SEQ ID NOs; 50-57, and truncates thereof.

19. The composition of claim 14 wherein the aptamer comprises at least one 2′-modified nucleotide.

20. The composition of claim 19 , wherein the aptamer comprises at least one modified nucleotide selected from the group consisting of a 2′-halo-modified nucleotide, a 2′-fluoro-modified nucleotide, and a 2′-O-alkyl-modified nucleotide.

21. The composition of claim 20 , wherein the aptamer comprises cytidines that are all 2′-deoxy-2′-fluorocytidine, or uridines that are all 2′-deoxy-2′-fluorouridine.

22. The composition of claim 14 , wherein the aptamer further comprises a covalently linked carrier selected from the group comprising; a soluble polymer, a biodegradable polymer, polyethylene glycol, or cholesterol.

23. The composition of claim 14 , wherein the composition is in a unit dose.

24. A method of modulating the biological activity of a coagulation pathway factor prothrombin or thrombin comprising administering an RNA aptamer that binds to the coagulation pathway factor prothrombin or thrombin to a host, wherein the RNA aptamer comprises, in a 5′ to 3′ direction, a first stem region a first loop region comprising a consensus sequence, the consensus sequence comprising AACAA, a second stem region, a second loop region, and a third loop region.

25. The method of claim 24 , wherein the aptamer has a dissociation constant of about 20 nanomolar (nM) or less.

26. The method of claim 25 , wherein the dissociation constant ranges from about 400 picomolar (pM) to about 10 nM.

27. The method of claim 25 , wherein the dissociation constant ranges from about 100 pM to about 10 nM.

28. The method of claim 24 , wherein the aptamer comprises at least one modified nucleotide.

29. The method of claim 28 , wherein the aptamer comprises at least one 2′-modified nucleotide.

30. The method of claim 29 , wherein the aptamer comprises at least one 2′-halo-modified nucleotide.

31. The method of claim 30 , wherein the aptamer comprises at least one 2′-fluoro-modified nucleotide.

32. The method of claim 29 , wherein the aptamer comprises at least one 2′-O-alkyl-modified nucleotide.

33. The method of claim 32 , wherein the aptamer comprises at least one 2′-methoxy-modified nucleotide.

34. The method of claim 28 , wherein at least one cytidine is 2′-deoxy- 2 ′ fluorocytidine.

35. The method of claim 28 , wherein at least one uridine is 2′-deoxy-2′-fluorouridine.

36. The method of claim 24 , wherein the aptamer comprises a 3′ chain terminator.

37. The method of claim 24 , wherein the aptamer comprises about 15 to 100 bases.

38. The method of claim 24 , wherein the aptamer comprises less than 100 bases.

39. The method of claim 38 , wherein the aptamer comprises less than 40 bases.

40. The method of claim 24 , wherein the aptamer comprises a covalently linked carrier.

41. The method of claim 40 , wherein the carrier is a soluble polymer.

42. The method of claim 40 , wherein the carrier is a biodegradable polymer.

43. The method of claim 40 , wherein the carrier is polyethylene glycol.

44. The method of claim 24 , wherein the aptamer additionally comprises a covalently linked cholesterol.

45. The method of claim 24 , wherein the first stem region comprises at least about 5 nucleotides at a 5′ end of the aptamer that form base pairs with at least about 5 nucleotides at a 3′ end of the aptamer.

46. The method of claim 24 , wherein the aptamer comprises a nucleotide sequence selected from the group consisting of SEQ ID NOs: 50-53, 55-57, and truncates thereof.

47. The method of claim 24 , wherein the aptamer comprises a nucleotide sequence at least 80% homologous to a nucleotide sequence selected from the group consisting of SEQ ID NOs: 50-53, 55-57, and truncates thereof.

48. The method of claim 24 , wherein the aptamer is administered by intravenous administration, intrasynovial administration, transdermal administration, intramuscular administration, subcutaneous administration, or topical administration to a blood vessel.

49. The method of claim 48 , wherein the aptamer is administered by subcutaneous administration.

50. The method of claim 24 , wherein the host suffers from a cardiovascular disease, and wherein the cardiovascular disease is selected from the group consisting of: atherosclerosis, thrombophilia, embolisms, cardiac infarction, thromboses, angina, stroke, septic shock, hypertension, hyper-cholesterolemia.