METHODS OF MESENCHYMAL STEM CELL MOBILIZATION AND EXPANSION

1 . A method of obtaining mesenchymal stem cells, the method comprising:

(a) administering to a subject an effective amount of a CXCR4 antagonistic peptide as set forth in SEQ ID NO: 1 so as to mobilize the mesenchymal stem cells to peripheral blood of the subject;

(b) collecting the mesenchymal stem cells from said peripheral blood; and subsequently or concomitantly;

(c) purifying the mesenchymal stem cells using a mesenchymal stem cell-specific phenotype.

2 . The method of claim 1 , wherein said mesenchymal stem cell-specific phenotype comprises at least one cell surface marker.

3 . The method of claim 1 , wherein said mesenchymal stem cell-specific phenotype comprises cell adherence.

4 . The method of claim 1 , wherein said mesenchymal stem cell-specific phenotype comprises immunosuppression.

5 . The method of claim 2 , using an antibody to said at least one cell surface marker.

6 . The method of claim 1 , wherein said collecting is effected 4-8 hours following said administering.

7 . The method of claim 1 , wherein said purifying comprises depleting mature hematopoietic cells.

8 . The method of claim 1 , wherein said administering is at a dose amount between 0.1 to 10 mg per kg of body weight.

9 . The method of claim 1 , wherein said CXCR4 antagonistic peptide is administered as a single mobilizing agent.

10 . An isolated population of cells obtained according to the method of claim 1 .

11 . The isolated population of cells of claim 1 , wherein at least 50% of the population are mesenchymal stem cells having a CD105+/CD45− signature.

12 . A method of cell expansion, the method comprising culturing mesenchymal stem cells in the presence of an effective amount of a CXCR4 antagonistic peptide as set forth in SEQ ID NO: 1, which support cell expansion.

13 . A method of producing a conditioned medium, the method comprising:

(a) culturing mesenchymal stem cells in the presence of an effective amount of a CXCR4 antagonistic peptide as set forth in SEQ ID NO: 1; and

(b) collecting a conditioned medium of said mesenchymal stem cells, thereby producing the conditioned medium.

14 . The method of claim 12 , wherein culturing is effected ex-vivo or in-vitro.

15 . The method of claim 10 , wherein said mesenchymal stem cells are comprised in a population substantially devoid of mature hematopoietic cells.

16 . A conditioned medium of the isolated population of cells of claim 10 .

17 . A pharmaceutical composition comprising as an active ingredient the isolated population of cells of claim 10 , and a pharmaceutically acceptable carrier or diluent.

18 . A method of treating a medical condition in a subject, which may benefit from mesenchymal stem cells transplantation, the method comprising administering to the subject a therapeutic effective amount of the isolated population of cells of claim 10 , thereby treating the medical condition in the subject.

19 . A method of treating a medical condition selected from the group consisting of a cosmetic treatment, replacing a tissue or an organ, or inducing or accelerating tissue repair or regeneration in a subject in need thereof, the method comprising administering to the subject a therapeutic effective amount of a CXCR4 antagonistic peptide as set forth in SEQ ID NO: 1, thereby treating the medical condition in the subject.

20 . The method of claim 1 , wherein said mesenchymal stem cells have a CD105+/CD45− signature.

21 . (canceled)