Quantification of adherent cell orientation and morphology under strong magnetic fields

Abstract

In the present study, the effect of magnetic fields on the orientation of adherent cells was investigated quantitatively using a long-term magnetic field exposure system at 8 T. Smooth muscle cells, which are classified as adherent cells, were passaged and dispersed in Dulbecco's Modified Eagle's Medium (DMEM). A cell culture flask was filled to capacity with the smooth muscle cell suspension, and placed in the center of a superconducting magnet's bore. The smooth muscle cell culture was incubated for 3 days, and exhibited randomly oriented patterns of rod-like shaped cells without magnetic field exposure. In contrast, the smooth muscle cell culture exposed to 8 Tesla (T) magnetic fields for 70 hours changed into a one-directionally oriented cell culture. To quantify the orientational order, an orientational order parameter for a 2-dimensional system was introduced by adapting the 3-dimensional order parameter. The degree of orientation of the culture with 8 T magnetic field exposure for 70 hours was 0.72, while the degree of orientation without exposure was 0.21. The results indicated that the magnetic orientational order of smooth muscle cells was lower than that of floating cells.

Studies on magnetism and bioelectromagnetics for 45 years: From magnetic analog memory to human brain stimulation and imaging

“…Torbet et al [1981] first observed the magnetic orientation of fibrin. We also observed the magnetic orientation of adherent cells such as osteoblasts [Kotani et al, 2000[Kotani et al, , 2002, vascular endothelial cells, smooth muscle cells [Umeno et al, 2001;Umeno and Ueno, 2003;Iwasaka and Ueno, 2003a,b;Iwasaka et al, 2003], human kidney cells , and Schwann cells [Eguchi et al, 2003a;Eguchi and Ueno, 2005] under 8 or 14 T magnetic field exposures.…”

“…We introduced an orientational order parameter to quantitatively evaluate the degree of orientation of adherent cells exposed to strong static magnetic fields [Umeno et al, 2001;Umeno and Ueno, 2003]. The value of the order parameter was estimated with the Fourier transform of microscopic images.…”

Detection of intracellular macromolecule behavior under strong magnetic fields by linearly polarized light

“…In our last study, we observed a novel phenomenon in which adherent smooth muscle cells directed their long axis along strong static magnetic fields of 8 T [Umeno et al, 2001]. A possible origin of the observed phenomenon was the diamagnetic anisotropy of smooth muscle cells, which have rodlike shapes, adhering on the substrate.…”

Observations of cellular responses to diamagnetic forces acting on cell components

“…Higashi et al [4] reported that red blood cells and blood platelets orient along the direction of magnetic flux. The effects of strong magnetic fields on adherent cell alignments with [5] and without [6] magnetically aligned collagen fibers have also been reported.…”