Mammalian cells enriched with functional mitochondria

An ex-vivo method for enriching human CD34+ bone-marrow cells with mitochondria, comprising:

• (i) providing a first composition, comprising a plurality of intact human CD34+ bone-marrow cells obtained or derived from a patient afflicted with a mitochondrial disease or from a subject not afflicted with a mitochondrial disease;
• (ii) providing a second composition, comprising a plurality of isolated intact functional human mitochondria obtained from a subject not afflicted with a mitochondrial disease;
• (iii) co-incubating the human CD34+ bone-marrow cells of the first composition with the isolated intact functional human mitochondria of the second composition, thus forming a third composition;
• and
• (iv) incubating the third composition under conditions allowing the human mitochondria to enter the human CD34+ bone-marrow cells thereby enriching said human CD34+ bone-marrow cells with said human intact functional mitochondria, thus forming a fourth composition;
• wherein the mitochondrial content of the human CD34+ bone-marrow cells in the fourth composition is higher than the mitochondrial content of the human CD34+ bone-marrow cells in the first composition.