Patent ID: 8080417

Claim:
A method of expanding and at the same time inhibiting differentiation of a population of CD 133+ hematopoietic stem cells, the method comprising selecting a population of CD133+ hematopoietic stem cells, ex-vivo co-culturing the selected hematopoietic stem cells with an amount of mesenchymal cells sufficient for feeder layer production under conditions which allow expanding and at the same time inhibiting differentiation of at least a portion of the CD133+ hematopoietic stem cells, wherein said conditions comprise culturing cells in the presence of serum and nicotinamide or a nicotinamide analog selected from the group consisting of benzamide, nicotinethioamide, nicotinic acid and α-amino-3-indolepropionic acid for at least three weeks; thereby expanding and at the same time inhibiting differentiation of said population of said CD133+ hematopoietic stem cells.