Cell penetrating peptides for intracellular delivery of molecules

1. A 10 or 11 amino acid cell-penetrating peptide characterized in that it comprises an amino acid sequence consisting of X 1 WX 2 RLX 3 X 4 X 5 X 6 X 7 X 8 (SEQ ID No: 5), wherein X 1 is beta-A or S; X 2 , X 6 , and X 7 are, independently from each other, W or F; X 5 is S or R, and X 8 is R or none, and wherein X 3 is R if X 5 is S, X 3 is S if X 5 is R X 4 is L or none if X 8 is R, and X 4 is L if X 8 is none.

2. The cell-penetrating peptide of claim 1 , wherein the amino acid sequence is selected from the group consisting of:

(SEQ ID No: 1)

X 1 WWRLSLRWW 

(SEQ ID No: 2)

X 1 WFRLSLRFWR 

(SEQ ID No: 3)

X 1 WWRLRSWFR,

and

(SEQ ID No: 4)

X 1 WFRLSLRFW,

wherein X 1 is beta-A or S.

3. The cell-penetrating peptide of claim 1 , further comprising, covalently linked to the N-terminal end of the amino acid sequence, one or several chemical entities selected from the group consisting of an acetyl, a fatty acid, a cholesterol, a poly-ethylene glycol, a nuclear localization signal, a nuclear export signal, an antibody, a polysaccharide, and a targeting molecule.

4. The cell-penetrating peptide of claim 1 , further comprising, covalently linked to the C-terminal end of said amino acid sequence, one or several groups selected from the group consisting of a cysteamide, a cysteine, a thiol, an amide, a nitrilotriacetic acid optionally substituted, a carboxyl, a linear or ramified C 1 -C 6 alkyl optionally substituted, a primary or secondary amine, an osidic derivative, a lipid, a phospholipid, a fatty acid, a cholesterol, a poly-ethylene glycol, a nuclear localization signal, a nuclear export signal, an antibody, a polysaccharide, and a targeting molecule.

5. A complex comprising a cell-penetrating peptide according to claim 1 and a cargo selected from the group consisting of peptides, peptide analogues, uncharged oligonucleotides, peptide nucleic acids (PNAs), and small hydrophobic molecules.

6. The complex of claim 5 , wherein said cargo is a molecule of at most 1.5 kDa.

7. The complex of claim 5 , wherein said cargo is an anticancer drug or an antiviral drug.

8. The complex of claim 5 , wherein said cargo is selected from the group consisting of amino acids, di- and tri-peptides, daunomycin, Paclitaxel, doxorubicin, azidothymidine (AZT), porphyrin, fluorescently labelled nucleosides and nucleotides, hydrophobic maghemite, and fluorescent dyes.

9. The complex of claim 5 , wherein said cargo is a cosmetic agent.

10. The complex of claim 5 , wherein the size of the complex is between 50 nm and 200 nm.

11. The complex of claim 5 , wherein the cell-penetrating peptide comprises a poly-ethylene glycol group covalently linked to its N-terminus, and/or a cysteamide group covalently linked to its C-terminus.

12. The complex of claim 5 , wherein at least part of the cell-penetrating peptides are bound to a targeting molecule.