A method of obtaining mesenchymal stem cells is provided. 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 the peripheral blood and subsequently or concomitantly(c) purifying the mesenchymal stem cells using a mesenchymal stem cell-specific phenotype.