Quantitative analysis of adherent cell orientation influenced by strong magnetic fields

This paper examines the effect of strong magnetic fields on adherent cells. Smooth muscle cells, cultured in 8- or 14-T superconducting magnets for three days, exhibited orientational order parallel to the magnetic field direction. To discuss the process and the mechanism of the orientation, the orientational characteristic of the cell culture was investigated with quantitative measurements: an orientational order parameter and the Fourier transform (FT) analysis. The orientational order parameter indicates the degree of orientation. The value of the parameter was estimated with the FT of microscopic images. The cells cultured under stronger static magnetic fields exhibited stronger ordering, while they showed weaker ordering in the control when they were cultured under a strong magnetic gradient force of 400 T2/m. The ordering was enhanced under uniform strong magnetic fields, while it was not affected or was suppressed by the strong gradient force. We suggest that the cells organize themselves to minimize their diamagnetic torsion stresses, which can be induced in the uniform magnetic fields by the membrane's diamagnetic anisotropy.