Peptide-mediated transfection agents and methods of use

• US 6,841,535 B2
• Filed: 07/26/2001
• Issued: 01/11/2005
• Est. Priority Date: 07/31/2000
• Status: Expired due to Term

• Current Assignee: Active Motif, Centre National De La Recherche Scientifique
• Original Assignee: Active Motif, Centre National De La Recherche Scientifique
• Inventors: Heitz, Frederic, Divita, Gilles, Mery, Jean, Morris, May C., Horndorp, Kyle, Fernandez, Joseph, Archdeacon, John
• Primary Examiner(s): Wax, Robert A.
• Application Number:
  US09/915,914
• Publication Number:
  US 20030119725A1
• Time in Patent Office: 1,265 Days
• Field of Search: 530/324, 530/326, 514/12, 514/13
• US Class Current: 424/130.1
• CPC Class Codes: A61K 38/00 Medicinal preparations containing peptides peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00
• CPC Class Codes: A61K 47/64 Drug-peptide, drug-protein or drug-polyamino acid conjugates, i.e. the modifying agent being a peptide, protein or polyamino acid which is covalently bonded or complexed to a therapeutically active agent peptidic linkers A61K47/65
• CPC Class Codes: C07K 14/001 by chemical synthesis
• CPC Class Codes: C07K 7/08 having 12 to 20 amino acids gastrins C07K14/595; somatostatins C07K14/655; melanotropins C07K14/68
• CPC Class Codes: C12N 15/87 Introduction of foreign genetic material using processes not otherwise provided for, e.g. co-transformation

Abstract

Peptides that are useful as transfection agents are described. The peptides can facilitate the efficient cellular internalization of a broad range and size of compounds that when non-covalently complexed therewith are efficiently internalized into a cell. Advantages include but are not limited to excellent transfection efficiency, relatively low toxicity, internalization by a broad host cell spectrum, and the simplicity and cost-effectiveness that arise from not having to covalently complex the peptide with a specific molecule to be delivered. Applications include but are not limited to the delivery of diagnostics and therapeutics, as well as drug discovery, gene discovery, and the analysis and/or manipulation of other cellular and molecular biological functions. Claims are made for transfection agents, compositions of matter, including pharmaceutical compositions, reagent kits, methods of delivery, and methods of identification of additional peptides for performing and/or including in the same.

Claims

1. A transfection agent comprising a peptide of between about 16 to 30 amino a acid residues, said peptide comprising:

a) a hydrophobic domain comprising at least four amino acid residues, wherein the hydrophobic domain comprises a plurality of aromatic amino acid residues and a first hydrophobic locus spaced by at least one amino acid residue from a second hydrohpobic locus, wherein each of the first and second hydrophobic loci comprise one or more hydrophobic amino acid residues independently selected from the group consisting of Phe, Tyr, Trp, Thr, Met, Leu, Val, Ile, Ala, and His, and wherein at least two of said plurality of aromatic amino acid residues occur in a pair in the first hydrophobic locus or the second hydrophobic locus;

b) a hydrophilic domain comprising up to about twelve amino acid residues, wherein the hydrophilic domain comprises a plurality of basic amino acid residues;

c) optionally a spacer sequence between said hydrophobic and said hydrophilic domain, wherein said spacer comprises from between one to about ten amino acid residues; and

d) further optionally a functional group conjugated to one or more termini of said peptide.

2. A transfection agent according to claim 1 wherein said hydrophilic domain is a cation-rich sequence comprised of at least two lysine residues within a span of seven residues.

3. A transfection agent according to claim 1 wherein at least two of said plurality of aromatic amino acid residues occur in a pair in the first hydrophobic locus or the second hydrophobic locus.

4. A transfection agent according to claim 2 wherein two or more of said at least two lysine residues are adjacent to one another.

5. A transfection agent according to claim 1 wherein said plurality of aromatic amino acid residues is between three and five aromatic amino acid residues inclusive.

6. A transfection agent according to claim 1 wherein said plurality of aromatic amino acid residues comprises at least two tryptophan residues.

7. A transfection agent according to claim 1 comprising two pairs of aromatic amino acid residues, the first pair being disposed in the first hydrophobic locus and the second pair being disposed in the second hydrophobic locus, and wherein said first and second hydrophobic loci are separated by two amino acids.

8. A transfection agent according to claim 7 wherein said two amino acids separating the first and second hydrophobic loci consist of hydrophilic amino acids.

9. A transfection agent according to claim 8 wherein said hydrophilic amino acids separating the first and second hydrophobic loci are Glu and Thr.

10. A transfection agent according to claim 1 wherein said peptide is a synthetic peptide.

11. A transfection agent according to claim 1 wherein said optional spacer sequence comprises one or more amino acid residues selected from the group consisting of proline, glycine, tyrosine, serine, glutamine, and non-charged amino acids.

12. A transfection agent according to claim 1 wherein said hydrophobic domain comprises a motif (Trp/Tyr)-(Trp/Tyr)-Xaa-Xaa-(Trp/Tyr), wherein the first and second hydrophobic loci are spaced by two amino acids, Xaa-Xaa, wherein each Xaa is a hydrophilic amino acid.

13. A transfection agent according to claim 1 wherein said agent is covalently affixed to a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivatives or analog of any of the foregoing.

14. A transfection agent according to claim 1 wherein said agent is non-covalently complexed with a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivative or analog of any of the foregoing.

15. A transfection agent according to claim 1 that further comprises a functional group covalently attached to a terminus of said peptide, wherein the functional group is selected from the group consisting of a cystearnine group, a methyl group, and an alkyl group, and, with respect to the amino terminus of said peptide, an acyl group.

16. A transfection agent according to claim 1 wherein said hydrophilic domain comprises the sequence Lys-Arg-Lys, and wherein said agent further comprises a spacer sequence that comprises at least three amino acid residues of which at least one is a proline or glutamine residue.

17. A transfection agent according to claim 1 that further comprises a functional group to which is covalently conjugated a molecule selected from the group consisting of a stabilizer, a coupler, a dye, a ligand, and an enzymatic substrate.

18. A commercial transfection kit comprising at least one transfection agent according to claim 1 in either aqueous or lyophilized form, said kit further comprising one or more components selected from the group consisting of buffers, positive controls, cells to be transfected, phospholipids, and instructions for use.

19. A pharmaceutical composition comprising a transfection agent according to claim 1.

20. A pharmaceutical composition according to claim 19 wherein said transfection agent is non-covalently complexed with a compound to be delivered to a cell.

21. A pharmaceutical composition according to claim 20 wherein said compound comprises a member selected from the group consisting of a diagnostic compound and a therapeutic compound.

22. A pharmaceutical composition according to claim 20 wherein said compound is a therapeutic compound that is effective to treat one or more afflictions selected from the group consisting of cancer and infectious diseases.

23. A pharmaceutical composition according to claim 20 wherein said compound targets a cell selected from the group consisting of a cancerous cell and a pathogen-infected cell.

24. A pharmaceutical composition according to claim 20 that is effective to transfect cells of interest using molar ratios of agent:

compound of between 5;

1 and 30;

1.

25. A pharmaceutical composition according to claim 20 in aqueous form in which the compound is present at a concentration of between about 0.1 uM and about 100 uM.

26. A pharmaceutical composition according to claim 20 in aqueous form in which the compound is present at a molar concentration of between about 1 uM and about 20 uM.

27. A transfection agent comprising a peptide of between about 16 to 30 amino acid residues, said peptide comprising:

a) a hydrophobic domain comprising at least four amino acid residues, wherein the hydrophobic domain comprises three to five aromatic amino acid residues and a first hydrophobic locus spaced by at least one amino acid residue from a second hydrohpobic locus, wherein each of the first and second hydrophobic loci comprise one or more hydrophobic amino acid residues independently selected from the group consisting of Phe, Tyr, Trp, Thr, Met, Leu, Val, Ile, Ala, and His;

b) a hydrophilic domain comprising up to about twelve amino acid residues, wherein the hydrophilic domain comprises a plurality of basic amino acid residues;

c) optionally a spacer sequence between said hydrophobic and said hydrophilic domain, wherein said spacer comprises from between one to about ten amino acid residues; and

d) further optionally a functional group conjugated to one or more termini of said peptide.

28. A transfection agent according to claim 27 wherein said hydrophilic domain is a cation-rich sequence comprised of at least two lysine residues within a span of seven residues.

29. The transfection agent of claim 27 wherein at least two of said plurality of aromatic amino acid residues occur in a pair in the first hydrophobic locus or the second hydrophobic locus.

30. The transfection agent of claim 28 wherein two or more of said at least two lysine residues are adjacent to one another.

31. The transfection agent of claim 27 wherein said plurality of aromatic amino acid residues is between three and five aromatic amino acid residues inclusive.

32. The transfection agent of claim 27 wherein said plurality of aromatic amino acid residues comprises at least two tryptophan residues.

33. The transfection agent of claim 27 comprising two pairs of aromatic amino acid residues, the first pair being disposed in the first hydrophobic locus and the second pair being disposed in the second hydrophobic locus, and wherein said first and second hydrophobic loci are separated by two amino acids.

34. The transfection agent of claim 33 wherein said two amino acids separating the first and second hydrophobic loci consist of hydrophilic amino acids.

35. The transfection agent of claim 34 wherein said hydrophilic amino acids separating the first and second hydrophobic loci are Glu and Thr.

36. A transfection agent according to claim 27 wherein said peptide is a synthetic peptide.

37. A transfection agent according to claim 27 wherein said optional spacer sequence comprises one or more amino acid residues selected from the group consisting of proline, glycine, tyrosine, serine, glutamine, and non-charged amino acids.

38. A transfection agent according to claim 27 wherein said hydrophobic domain comprises a motif (Trp/Tyr)-(Trp/Tyr)-Xaa-Xaa-(Trp/Tyr), wherein the first and second hydrophobic loci are spaced by two amino acids, Xaa-Xaa, wherein each Xaa is a hydrophilic amino acid.

39. A transfection agent according to claim 27 wherein said agent is covalently affixed to a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivative or analog of any of the foregoing.

40. A transfection agent according to claim 27 wherein said agent is non-covalently complexed with a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivative or analog of any of the foregoing.

41. A transfection agent according to claim 27 that further comprises a functional group covalently attached to a terminus of said peptide, wherein the functional group is selected from the group consisting of a cysteamine group, a methyl group, and an alkyl group, and, with respect to the amino terminus of said peptide, an acyl group.

42. A transfection agent according to claim 27 wherein said hydrophilic domain comprises the sequence Lys-Arg-Lys, and wherein said agent further comprises a spacer sequence that comprises at least three amino acid residues of which at least one is a proline or glutamine residue.

43. A transfection agent according to claim 27 that further comprises a functional group to which is covalently conjugated a molecule selected from the group consisting of a stabilizer, a coupler, a dye, a ligand, and an enzymatic substrate.

44. A commercial transfection kit comprising at least one transfection agent according to claim 27 in either aqueous or lyophilized form, said kit further comprising one or more components selected from the group consisting of buffers, positive controls, cells to be transfected, phospholipids, and instructions for use.

45. A pharmaceutical composition comprising a transfection agent according to claim 27.

46. A pharmaceutical composition according to claim 45 wherein said transfection agent is non-covalently complexed with a compound to be delivered to a cell.

47. A pharmaceutical composition according to claim 46 wherein said compound comprises a member selected from the group consisting of a diagnostic compound and a therapeutic compound.

48. A pharmaceutical composition according to claim 46 wherein said compound is a therapeutic compound that is effective to treat one or more afflictions selected from the group consisting of cancer and infectious diseases.

49. A pharmaceutical composition according to claim 46 wherein said compound targets a cell selected from the group consisting of a cancerous cell and a pathogen-infected cell.

50. A pharmaceutical composition according to claim 46 that is effective to transfect cells of interest using molar ratios of agent:

compound of between 5;

1 and 30;

1.

51. A phannaceutical composition according to claim 46 in aqueous form in which the compound is present at a concentration of between about 0.1 uM and about 100 uM.

52. A pharmaceutical composition according to claim 46 in aqueous form in which the compound is present at a molar concentration of between about 1 uM and about 20 uM.

53. A transfection agent comprising a peptide of between about 16 to 30 amino acid residues, said peptide comprising:

a) a hydrophobic domain comprising at least four amino acid residues, wherein the hydrophobic domain comprises a plurality of aromatic amino acid residues and a first hydrophobic locus spaced by at least one amino acid residue from a second hydrohpobic locus, wherein each of the first and second hydrophobic loci comprise one or more hydrophobic amino acid residues independently selected from the group consisting of Phe, Tyr, Trp, Thr, Met, Leu, Val, Ile, Ala, and His;

b) a hydrophilic domain comprising up to about 12 amino acid residues, wherein the hydrophilic domain comprises a plurality of basic amino acid residues;

c) optionally a spacer sequence between said hydrophobic and said hydrophilic domains, wherein said spacer comprises from between one to about ten amino acid residues; and

d) further optionally a functional group conjugated to one or more termini of said peptide.

54. A transfection agent according to claim 53 wherein said hydrophilic domain is a cation-rich sequence comprised of at least two lysine residues within a span of seven residues.

55. The transfection agent of claim 53 wherein at least two of said plurality of aromatic amino acid residues occur in a pair in the first hydrophobic locus or the second hydrophobic locus.

56. The transfection agent of claim 54 wherein two or more of said at least two lysine residues are adjacent to one another.

57. The transfection agent of claim 53 wherein said plurality of aromatic amino acid residues is between three and five aromatic amino acid residues inclusive.

58. The transfection agent of claim 53 wherein said plurality of aromatic amino acid residues comprises at least two tryptophan residues.

59. The transfection agent of claim 53 comprising two pairs of aromatic amino acid residues, the first pair being disposed in the first hydrophobic locus and the second pair being disposed in the second hydrophobic kcus, and wherein said first and second hydrophobic loci are separated by two amino acids.

60. The transfection agent of claim 59 wherein said two amino acids separating the first and second hydrophobic loci consist of hydrophilic amino acids.

61. The transfection agent of claim 60 wherein said hydrophilic amino acids separating the first and second hydrophobic loci are Glu and Thr.

62. A transfection agent according to claim 53 wherein said peptide is a synthetic peptide.

63. A transfection agent according to claim 53 wherein said optional spacer sequence comprises one or more amino acid residues selected from the group consisting of proline, glycine, tyrosine, serine, glutamine, and non-charged amino acids.

64. A transfection agent according to claim 53 wherein said hydrophobic domain comprises a motif (Trp/Tyr)-(Trp/Tyr)-Xaa-Xaa-(Trp/Tyr), wherein the first and second hydrophobic loci are spaced by two amino acids, Xaa-Xaa, wherein each Xaa is a hydrophilic amino acid.

65. A transfection agent according to claim 53 wherein said agent is covalently affixed to a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivative/or analog of any of the foregoing.

66. A transfection agent according to claim 53 wherein said agent is non-covalently complexed with a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivatives or analog of any of the foregoing.

67. A transfection agent according to claim 53 that further comprises a functional group covalently attached to a terminus of said peptide, wherein the functional group is selected from the group consisting of a cysteanline group, a methyl group, and an alkyl group, and, with respect to the amino terminus of said peptide, an acyl group.

68. A transfection agent according to claim 53 wherein said hydrophilic domain comprises the sequence Lys-Arg-Lys, and wherein said agent further comprises a spacer sequence that comprises at least three amino acid residues of which at least one is a proline or glutamine residue.

69. A transfection agent according to claim 53 that further comprises a functional group to which is convalently conjugated a molecule selected from the group consisting of a stabilizer, a coupler, a dye, a ligand, and an enzymatic substrate.

70. A commercial transfection kit comprising at least one transfection agent according to claim 53 in either aqueous or lyophilized form, said kit further comprising one or more components selected from the group consisting of buffers, positive controls, cells to be transfected, phospholipids, and instructions for use.

71. A pharmaceutical composition comprising a transfection agent according to claim 53.

72. A pharmaceutical composition according to claim 71 wherein said transfection agent is non-covalently complexed with a compound to be delivered to a cell.

73. A pharmaceutical composition according to claim 72 wherein said compound comprises a member selected from the group consisting of a diagnostic compound and a therapeutic compound.

74. A pharmaceutical composition according to claim 72 wherein said compound is a therapeutic compound that is effective to treat one or more afflictions selected from the group consisting of cancer and infectious diseases.

75. A pharmaceutical composition according to claim 72 wherein said compound targets a cell selected from the group consisting of a cancerous cell and a pathogen-infected cell.

76. A pharmaceutical composition according to claim 72 that is effective to transfect cells of interest using molar ratios of agent:

compound of between 5;

1 and 30;

1.

77. A pharmaceutical composition according to claim 72 in aqueous form in which the compound is present at a concentration of between about 0.1 uM and about 100 uM.

78. A pharmaceutical composition according to claim 72 in aqueous form in which the compound is present at a molar concentration of between about 1 uM and about 20 uM.

79. A transfection agent comprising a peptide of between about 16 to 30 amino acid residues in length, said peptide comprising:

a) a hydrophobic domain comprising at least four amino acid residues, wherein the hydrophobic domain comprises a first hydrophobic locus spaced by at least one amino acid residue from a second hydrohpobic locus, wherein each of the first and second hydrophobic loci comprise one or more hydrophobic amino acid residues independently selected from the group consisting of Phe, Tyr, Trp, Thr, Met, Leu, Val, Ile, Ala, and His;

b) a hydrophilic domain comprising up to about 12 amino acid residues, wherein the hydrophilic domain comprises a plurality of basic amino acid residues;

c) optionally a spacer sequence between said hydrophobic and said hydrophilic domains, wherein said spacer comprises from between one to about ten amino acid residues; and

d) further optionally a functional group conjugated to one or more termini of said peptide,

wherein the peptide comprises an amino acid sequence selected from the group consisting of SEQ ID NO. 1 through 12.

80. A transfection agent according to claim 79 wherein said peptide is a synthetic peptide.

81. A transfection agent according to claim 79 wherein said agent is covalently affixed to a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivative or analog of any of the foregoing.

82. A transfection agent according to claim 79 wherein said agent is non-covalently complexed with a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivatives or analog of any of the foregoing.

83. A transfection agent according to claim 79 that further comprises a functional group covalently attached to a terminus of said peptide, wherein the functional group is selected from the group consisting of a cysteamine group, a methyl group, and an alkyl group, and, with respect to the amino terminus of said peptide, an acyl group.

84. A transfection agent according to claim 79 wherein said hydrophilic domain comprises the sequence Lys-Arg-Lys, and wherein said agent further comprises a spacer sequence that comprises at least three amino acid residues of which at least one is a proline or glutamine residue.

85. A transfection agent according to claim 79 that further comprises a functional group to which is covelently conjugated a molecule selected from the group consisting of a stabilizer, a coupler, a dye, a ligand, and an enzymatic substrate.

86. A commercial transfection kit comprising at least one transfection agent according to claim 79 in either aqueous or lyophilized form, said kit further comprising one or more components selected from the group consisting of buffers, positive controls, cells to be transfected, phospholipids, and instructions for use.

87. A pharmaceutical composition comprising a transfection agent according to claim 79.

88. A pharmaceutical composition according to claim 87 wherein said transfection agent is non-covalently complexed with a compound to be delivered to a cell.

89. A pharmaceutical composition according to claim 88 wherein said compound comprises a member selected from the group consisting of a diagnostic compound and a therapeutic compound.

90. A pharmaceutical composition according to claim 88 wherein said compound is a therapeutic compound that is effective to treat one or more afflictions selected from the group consisting of cancer and infectious diseases.

91. A pharmaceutical composition according to claim 88 wherein said compound targets a cell selected from the group consisting of a cancerous cell and a pathogen-infected cell.

92. A pharmaceutical composition according to claim 88 that is effective to transfect cells of interest using molar ratios of agent:

compound of between 5;

1 and 30;

1.

93. A pharmaceutical composition according to claim 88 in aqueous form in which the compound is present at a concentration of between about 0.1 uM and about 100 uM.

94. A pharmaceutical composition according to claim 88 in aqueous form in which the compound is present at a molar concentration of between about 1 uM and about 20 uM.

95. A commercial transfection kit comprising at least one transfection agent comprising a peptide of between about 16 to 30 amino acid residues, said peptide comprising:

a) a hydrophobic domain comprising at least four amino acid residues, wherein the hydrophobic domain comprises a first hydrophobic locus spaced by at least one amino acid residue from a second hydrohpobic locus, wherein each of the first and second hydrophobic loci comprise one or more hydrophobic amino acid residues independently selected from the group consisting of Phe, Tyr, Trp, Thr, Met, Leu, Val, Ile, Ala, and His;

b) a hydrophilic domain comprising up to about 12 amino acid residues, wherein the hydrophilic domain comprises a plurality of basic amino acid residues;

c) optionally a spacer sequence between said hydrophobic and said hydrophilic domains, wherein said spacer comprises from between one to about ten amino acid residues; and

d) further optionally a functional group conjugated to one or more termini of said peptide,

wherein the transfection agent is in either aqueous or lyophilized form, and wherein said kit further comprises one or more components selected from the group consisting of buffers, positive controls, cells to be transfected, phospholipids, and instructions for use.

96. A kit according to claim 95 wherein said hydrophilic domain is a cation-rich sequence comprised of at least two lysine residues within a span of seven residues.

97. A kit according to claim 95 wherein at least two of said plurality of aromatic amino acid residues occur in a pair in the first hydrophobic locus or the second hydrophobic locus.

98. A kit according to claim 96 wherein two or more of said at least two lysine residues are adjacent to one another.

99. A kit according to claim 95 wherein said plurality of aromatic amino acid residues is between three and five aromatic amino acid residues inclusive.

100. A kit according to claim 95 wherein said plurality of aromatic amino acid residues comprises at least two tryptophan residues.

101. A kit according to claim 95 comprising two pairs of aromatic amino acid residues, the first pair being disposed in the first hydrophobic locus and the second pair being disposed in the second hydrophobic locus, and wherein said first and second hydrophobic loci are separated by two amino acids.

102. A kit according to claim 101 wherein said two amino acids separating the first and second hydrophobic loci consist of hydrophilic amino acids.

103. A kit according to claim 102 wherein said hydrophilic amino acids separating the first and second hydrophobic loci are Glu and Thr.

104. A kit according to claim 95 wherein said peptide is a synthetic peptide.

105. A kit according to claim 95 wherein said optional spacer sequence comprises one or more amino acid residues selected from the group consisting of proline, glycine, tyrosine, serine, glutamine, and non-charged amino acids.

106. A kit according to claim 95 wherein said hydrophobic domain comprises a motif (Trp/Tyr)-(Trp/Tyr)-Xaa-Xaa-(Trp/Tyr), wherein the first and second hydrophobic loci are spaced by two amino acids, Xaa-Xaa, wherein each Xaa is a hydrophilic amino acid.

107. A kit according to claim 95 wherein said agent is covalently affixed to a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivatives or analog of any of the foregoing.

108. A kit according to claim 95 wherein said agent is non-covalently complexed with a compound selected from the group consisting of a nucleic acid, a peptide, a protein, an antibody, and a derivatives or analog of any of the foregoing.

109. A kit according to claim 95 that further comprises a functional group covalently attached to a terminus of said peptide, wherein the functional group is selected from the group consisting of a cysteamine group, a methyl group, and an alkyl group, and, with respect to the amino terminus of said peptide, an acyl group.

110. A kit according to claim 95 wherein said hydrophilic domain comprises the sequence Lys-Arg-Lys, and wherein said agent further comprises a spacer sequence that comprises at least three amino acid residues of which at least one is a proline or glutamine residue.

111. A kit according to claim 95 that further comprises a functional group to which is covelently conjugated a molecule selected from the group consisting of a stabilizer, a coupler, a dye, a ligand, and an enzymatic substrate.

112. A kit according to claim 95 wherein the transfection agent is formulated as a pharmaceutical composition.

113. A kit according to claim 112 wherein said transfection agent is non-covalently complexed with a compound to be delivered to a cell.

114. A kit according to claim 113 wherein said compound comprises a member selected from the group consisting of a diagnostic compound and a therapeutic compound.

115. A kit according to claim 113 wherein said compound is a therapeutic compound that is effective to treat one or more afflictions selected from the group consisting of cancer and infectious diseases.

116. A kit according to claim 113 wherein said compound targets a cell selected from the group consisting of a cancerous cell and a pathogen-infected cell.

117. A kit according to claim 113 wherein said compound is effective to transfect cells of interest using molar ratios of agent:

compound of between 5;

1 and 30;

1.

118. A kit according to claim 113 wherein said composition is in aqueous form and the compound is present at a concentration of between about 0.1 uM and about 100 uM.

119. A kit according to claim 113 wherein said composition is in aqueous form and the compound is present at a molar concentration of between about 1 uM and about 20 uM.