We evaluated the differentiation potential of CD34-cells expanded from human cord blood into several differentiated cells, namely, osteoblasts, chondrocytes and adipocytes.

CD34-cells, extracted from cord blood and isolated using a MiniMACS system, were cultured. Cells labeled with appropriate antibodies were analyzed by FACScan. The phenotypes of adipogenic and osteogenic differentiation were evaluated by Oil Red O, alkaline phosphatase, and von Kossa staining. Chondrogenic differentiation was evaluated by RT-PCR using primers for aggrecan, collagen types I, II and X.

CD34-cells showed a fibroblast-like morphology and expressed CD105, CD29, and CD44 antigens. These cells showed the deposition of a mineralized matrix and the expression of alkaline phosphatase in the osteogenic medium, and stained with Oil Red O in the adipogenic medium. In terms of chondrogenic differentiation, the expressions of aggrecan, and collagen types II and X showed a gradual increase, whereas the expression of type I collagen gradually decreased.

Based on their differentiation potentials in at least three different tissue types, i.e., fat, bone, and cartilage, cord blood-derived CD34- cells can be visualized as attractive target cells for cellular or gene transfer therapeutic options.