Osteogenic enrichment of bone-marrow stromal cells with the use of flow chamber and type I collagen-coated surface

The stromal cells of the bone marrow are able to attach to the surface and differentiate into cells with bone‐forming capability when stimulated with osteogenic supplements. In this study, we have employed a flow‐chamber device containing a collagen‐coated surface to enrich the potential osteoprogenitor cells from bone marrow stromal cells (BMSCs). The population of the cells attached to the collagen‐coated substratum is about twice that attached to the uncoated surface. In the flow chamber, almost all marrow cells attached on the untreated glass were flushed out at the shear stress of 1.10 dyne/cm2. On the other hand, 25% of the marrow cells remained attached to the collagen‐coated glass, even under the shear stress of 1.30 dyne/cm2. The collagen‐attached marrow cells exhibited similar, specific alkaline phosphatase activity compared with that of the cells attached to the uncoated dish in the early stage of culturing. Nevertheless, only the collagen‐attached marrow cells later expressed significant amounts of osteocalcin, which is a specific marker for osteoblast cells. Thus, we have successfully developed a protocol that uses a collagen‐coated surface efficiently in a flow chamber to enrich the osteogenic cells from the BMSCs. This provides a useful tool to obtain osteogenic cells from bone marrow for biologic and clinical applications. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 38–46, 2003