Continuous separation of cells of high osteoblastic differentiation potential from mesenchymal stem cells on an antibody-immobilized column.

Here, we report that two distinctive cell populations with osteoblastic differentiation ability were found in adherent cell populations from bone marrow. Mesenchymal stem cells (MSCs) were conventionally isolated by using adherent property of bone marrow cells onto a plastic culture dish. MSCs enriched on the basis of their adherent property were considered phenotypically and functionally heterogeneous. We developed a ligand-immobilized surface for separating subpopulation of adherent cells derived from bone marrow by the cell rolling process. We successfully isolate two cell populations with high differentiation ability for osteoblasts in adherent bone marrow cells by using the anti-CD34 antibody-immobilized column. The antibody was covalently conjugated with polyacrylic acid and introduced onto the inner surface of a silicone tube. When cell suspension of MSCs was injected into the antibody-immobilized column, different cell populations were isolated. After the cultivation of isolated cells in the osteoblastic differentiation medium for 1 week, few sub-populations were strongly induced to form osteoblastic cells. This study revealed that the ligand-immobilized surface can be used to continually separate cell populations under a labeling-free condition.