Magnetic iron oxide nanoparticles (MNPs) have been under intense investigation for at least the last five decades as they show enormous potential for many biomedical applications, such as biomolecule separation, MRI imaging and hyperthermia. Moreover, a large area of research on these nanostructures is concerned with their use as carriers of drugs, nucleic acids, peptides and other biologically active compounds, often leading to the development of targeted therapies. The uniqueness of MNPs is due to their nanometric size and unique magnetic properties. In addition, iron ions, which, along with oxygen, are a part of the MNPs, belong to the trace elements in the body. Therefore, after digesting MNPs in lysosomes, iron ions are incorporated into the natural circulation of this element in the body, which reduces the risk of excessive storage of nanoparticles. Still, one of the key issues for the therapeutic applications of magnetic nanoparticles is their pharmacokinetics which is reflected in the circulation time of MNPs in the bloodstream. These characteristics depend on many factors, such as the size and charge of MNPs, the nature of the polymers and any molecules attached to their surface, and other. Since the pharmacokinetics depends on the resultant of the physicochemical properties of nanoparticles, research should be carried out individually for all the nanostructures designed. Almost every year there are new reports on the results of studies on the pharmacokinetics of specific magnetic nanoparticles, thus it is very important to follow the achievements on this matter. This paper reviews the latest findings in this field. The mechanism of action of the mononuclear phagocytic system and the half-lives of a wide range of nanostructures are presented. Moreover, factors affecting clearance such as hydrodynamic and core size, core morphology and coatings molecules, surface charge and technical aspects have been described.

中文翻译：

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医用磁性氧化铁纳米粒子的药代动力学

至少在过去的五年中，磁性氧化铁纳米粒子 (MNP) 一直在进行深入研究，因为它们在许多生物医学应用中显示出巨大的潜力，例如生物分子分离、MRI 成像和热疗。此外，对这些纳米结构的大量研究涉及将它们用作药物、核酸、肽和其他生物活性化合物的载体，这通常会导致靶向治疗的发展。MNPs 的独特性在于它们的纳米尺寸和独特的磁性。此外，铁离子与氧一起构成MNPs的一部分，属于体内的微量元素。因此，在溶酶体中消化MNPs后，铁离子被纳入体内这种元素的自然循环中，这降低了纳米颗粒过度储存的风险。尽管如此，磁性纳米粒子治疗应用的关键问题之一是它们的药代动力学，这反映在 MNP 在血流中的循环时间上。这些特性取决于许多因素，例如 MNP 的大小和电荷、聚合物的性质和附着在其表面的任何分子等。由于药代动力学取决于纳米粒子的物理化学性质的结果，因此应针对所有设计的纳米结构单独进行研究。几乎每年都有关于特定磁性纳米粒子药代动力学研究结果的新报道，因此关注这方面的成果非常重要。本文回顾了该领域的最新发现。介绍了单核吞噬系统的作用机制和各种纳米结构的半衰期。此外，还描述了影响间隙的因素，例如流体动力学和核心尺寸、核心形态和涂层分子、表面电荷和技术方面。