High-potential human mesenchymal stem cells.

Bone marrow-derived stromal mesenchymal stem cells (MSCs) have been characterized in vitro by their growth characteristics, the expression of a panel of surface antigens, and their potential to differentiate into mesenchymal lineages. They can be separated by physical methods as well as by immunological or chemical separation or cultivation. Different protocols are used in different laboratories, making the comparison of various reported MSC populations difficult. Here we describe a population of bone marrow-derived adult stem cells that has been separated on a Percoll gradient with low density. It is characterized by an extraordinary high proliferative potential and a conserved phenotype characteristic of MSCs that retain their plutipotentiality in culture, as evidenced by their ability to differentiate into osteo-, chondro-, and adipogenic lineages. Separation of these cells provide an effective and convenient method for rapid expansion of pluripotential human MSCs for clinical use where large amounts of stem cells are needed.