Magnetic nanoparticles are well known for anticancer activity by deregulating cellular functions. In the present study, cellular effects of low strength static magnetic field (SMF) were explored. How nanoparticles affect the cellular response in presence and absence of static magnetic field was also studied. Peripheral blood mononuclear cells (PBMC) and human lymphoma monocytic cell line U937 were chosen as representative normal and cancer cells models. The two effects we would like to report in this paper are, DNA damage induced by SMF of the order of 70 mT, and alteration in membrane potential. The other notable aspect was the changes were diametrically opposite in normal and cancer cell types. DNA damage was observed only in cancer cells whereas membrane depolarization was observed in normal cells. Iron oxide nanoparticles (IONP) and gold nanoparticles (AuNP) were also used for cellular response studies in presence and absence of SMF. The effects of the magnetic nanoparticle IONP and also of AuNP were sensitive to presence of SMF. Unlike cancer cells, normal cells showed a transient membrane depolarization sensitive to static magnetic field. This depolarization effect exclusive for normal cells was suggested to have correlations with their higher repair capacity and lesser propensity for DNA damage. The work shows cancer cells and normal cells respond to nanoparticle and static magnetic field in different ways. The static magnetic induced DNA damage observed exclusively in cancer cells may have therapeutic implications. From the conclusions of the present investigation we may infer that static magnetic field enhances the therapeutic potentials of nanoparticles. Such low strength magnetic field seems to be a promising external manoeuvring agent in designing theranostics.

中文翻译：

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外部磁场对癌细胞中纳米颗粒的细胞毒性和遗传毒性作用的调节。

众所周知，磁性纳米颗粒通过调节细胞功能而具有抗癌活性。在本研究中，探索了低强度静磁场（SMF）的细胞效应。还研究了纳米粒子如何在存在和不存在静磁场的情况下影响细胞反应。选择外周血单核细胞（PBMC）和人淋巴瘤单核细胞系U937作为代表性的正常和癌细胞模型。我们要在本文中报道的两种效应是，由SMF诱导的DNA损伤（约70 mT）和膜电位的改变。另一个值得注意的方面是，正常细胞和癌细胞类型的变化完全相反。仅在癌细胞中观察到DNA损伤，而在正常细胞中观察到膜去极化。在存在和不存在SMF的情况下，氧化铁纳米颗粒（IONP）和金纳米颗粒（AuNP）也用于细胞反应研究。磁性纳米粒子IONP和AuNP的作用对SMF的存在很敏感。不同于癌细胞，正常细胞表现出对静磁场敏感的瞬时膜去极化。有人认为，正常细胞专有的这种去极化作用与其较高的修复能力和较低的DNA损伤倾向有关。研究表明癌细胞和正常细胞以不同的方式对纳米粒子和静磁场作出反应。仅在癌细胞中观察到的静电诱导的DNA损伤可能具有治疗意义。从本研究的结论中，我们可以推断出静磁场增强了纳米颗粒的治疗潜力。这样的低强度磁场似乎是设计诊断学的有希望的外部手段。