On the origin of biological effects of time varying magnetic field: Quantitative insights

Abstract

In a number of recently published experimental studies from our research group, the positive impact of the magnetic stimuli (static/pulsed) on cell functionality modulation or bactericidal effect, in vitro has been established. In order to develop the theoretical understanding towards such magnetobiological effects, the present study is aimed to present two quantitative models to determine magnetic Maxwell stresses as well as pressure acting on the cell membrane, under the influence of time varying magnetic field. The model predicts that magnetic field induced stress on the cell/bacterial is dependent on the conductivity properties of extracellular region and is determined to be of significantly lower magnitude to cause any significant effect. However, the force on the cell/bacteria due to electric field is more significant and was used to determine the membrane tension that can cause membrane poration. With a known critical membrane tension for cells, the field parameters necessary to cause membrane rupture were determined. Based on the experimental results and theoretically predicted values, the field parameters can be classified into three regimes, wherein the magnetic fields cause no effect or result in biophysical stimulation or induce cell death due to membrane damage. Taken together, this work provides some quantitative insights into the impact of magnetic field on the biological system.