Faculty of Engineering and Interdisciplinary Sciences, Jamia Hamdard, Hamdard University, New Delhi, India.
Int J Nanomedicine. 2010 Nov 16;5:983-9. doi: 10.2147/IJN.S13244.
Iron oxide nanoparticles with unique magnetic properties have a high potential for use in several biomedical, bioengineering and in vivo applications, including tissue repair, magnetic resonance imaging, immunoassay, drug delivery, detoxification of biologic fluids, cell sorting, and hyperthermia. Although various surface modifications are being done for making these nonbiodegradable nanoparticles more biocompatible, their toxic potential is still a major concern. The current in vitro study of the interaction of superparamagnetic iron oxide nanoparticles of mean diameter 30 nm coated with Tween 80 and murine macrophage (J774) cells was undertaken to evaluate the dose- and time-dependent toxic potential, as well as investigate the role of oxidative stress in the toxicity. A 15-30 nm size range of spherical nanoparticles were characterized by transmission electron microscopy and zeta sizer. MTT assay showed >95% viability of cells in lower concentrations (25-200 μg/mL) and up to three hours of exposure, whereas at higher concentrations (300-500 μg/mL) and prolonged (six hours) exposure viability reduced to 55%-65%. Necrosis-apoptosis assay by propidium iodide and Hoechst-33342 staining revealed loss of the majority of the cells by apoptosis. H₂DCFDDA assay to quantify generation of intracellular reactive oxygen species (ROS) indicated that exposure to a higher concentration of nanoparticles resulted in enhanced ROS generation, leading to cell injury and death. The cell membrane injury induced by nanoparticles studied using the lactate dehydrogenase assay, showed both concentration- and time-dependent damage. Thus, this study concluded that use of a low optimum concentration of superparamagnetic iron oxide nanoparticles is important for avoidance of oxidative stress-induced cell injury and death.
具有独特磁性的氧化铁纳米粒子在多个生物医学、生物工程和体内应用中具有很高的应用潜力，包括组织修复、磁共振成像、免疫测定、药物输送、生物体液解毒、细胞分选和热疗。尽管正在进行各种表面修饰以使这些不可生物降解的纳米粒子更具生物相容性，但它们的毒性潜力仍然是一个主要关注点。目前，对涂有吐温 80 的平均直径为 30nm 的超顺磁性氧化铁纳米粒子与小鼠巨噬细胞（J774）细胞的相互作用进行了体外研究，以评估剂量和时间依赖性毒性潜力，并研究氧化应激在毒性中的作用。通过透射电子显微镜和zeta 粒度仪对 15-30nm 尺寸范围的球形纳米粒子进行了表征。MTT 测定法表明，在较低浓度（25-200μg/mL）和长达 3 小时的暴露时间内，细胞活力>95%，而在较高浓度（300-500μg/mL）和较长时间（6 小时）暴露时，细胞活力降低至 55%-65%。碘化丙啶和 Hoechst-33342 染色的坏死-凋亡测定法显示，大多数细胞通过凋亡而丧失。用于量化细胞内活性氧（ROS）生成的 H₂DCFDDA 测定法表明，暴露于更高浓度的纳米粒子会导致 ROS 生成增强，从而导致细胞损伤和死亡。使用乳酸脱氢酶测定法研究纳米粒子引起的细胞膜损伤，显示出浓度和时间依赖性损伤。因此，本研究得出结论，使用低最佳浓度的超顺磁性氧化铁纳米粒子对于避免氧化应激诱导的细胞损伤和死亡很重要。
