Magnetic Cell Orientation Depending on Cell Type and Cell Density

To clarify the mechanism of magnetic orientation of adherent cells, we investigated the relationship between the magnetic cell orientation and the related factors such as cell type and cell density. A7r5 cells (smooth muscle cell, spindle shaped), GI-1 cells (human glioma, spindle shaped), and HEK293 cells (human kidney cell, polygonal shaped) were exposed to 8 T static magnetic fields, which were produced by a superconducting magnet, for 60 h at 37/spl deg/C. A7r5 and GI-1 cells were oriented under the magnetic field, however, HEK293 cells were not oriented. A7r5 cells were oriented by the magnetic field only when the cells were actively proliferating at high cell density. On the other hand, when the cells were in the confluent condition at the start point of the magnetic field exposure, the cells were not oriented. We conclude that the magnetic field affected on the cell division process, and only the proliferating cells at high density were oriented under the magnetic field.