Towards predicting intracellular radiofrequency radiation effects

Recent experiments have reported an effect of weak radiofrequency magnetic fields in the MHz-range on the concentrations of reactive oxygen species (ROS) in living cells. Since the energy that could possibly be deposited by the radiation is orders of magnitude smaller than the energy of molecular thermal motion, it was suggested that the effect was caused by the interaction of RF magnetic fields with transient radical pairs within the cells, affecting the ROS formation rates through the radical pair mechanism. It is, however, at present not entirely clear how to predict RF magnetic field effects at certain field frequency and intensity in nanoscale biomolecular systems. We suggest a possible recipe for interpreting the radiofrequency effects in cells by presenting a general workflow for calculation of the reactive perturbations inside a cell as a function of RF magnetic field strength and frequency. To justify the workflow, we discuss the effects of radiofrequency magnetic fields on generic spin systems to particularly illustrate how the reactive radicals could be affected by specific parameters of the experiment. We finally argue that the suggested workflow can be used to predict effects of radiofrequency magnetic fields on radical pairs in biological cells, which is specially important for wireless recharging technologies where one has to know of any harmful effects that exposure to such radiation might cause.近期已有实验报道，兆赫兹频段的弱射频磁场（radiofrequency magnetic fields）会对活细胞内活性氧簇（reactive oxygen species, ROS）的浓度产生影响。由于该辐射所能沉积的能量相较于分子热运动能量低数个数量级，有研究提出该效应源于射频磁场与细胞内瞬态自由基对（transient radical pairs）的相互作用，并通过自由基对机制（radical pair mechanism）改变活性氧簇的生成速率。然而目前，针对纳米级生物分子系统，如何预测特定频率与强度的射频磁场效应，仍未完全明晰。本研究提出一种可用于阐释细胞内射频效应的可行方法，通过构建通用计算流程，实现基于射频磁场强度与频率的细胞内反应扰动预测。为验证该流程的合理性，本文讨论了射频磁场对通用自旋系统（spin systems）的影响，以具体说明实验参数如何对反应性自由基产生作用。本文最终提出，所提出的计算流程可用于预测射频磁场对生物细胞内自由基对的影响，这一点对于无线充电技术（wireless recharging technologies）尤为关键——此类技术需要明确该类辐射暴露可能引发的潜在有害效应。