磁性氧化铁纳米颗粒（磁铁矿和红铁矿）由于其在医学和生物科学中广泛应用的潜力而被密切研究。它们独特的性质，如纳米尺寸、大比表面积和超顺磁性，使其可以在目标药物传递和内部放射治疗中利用外部磁场进行定向应用。此外，它们还被成功应用于磁共振成像（MRI）、局部热疗和放射性标记。通过适当的纳米颗粒设计，可以将其传递到所需的组织和器官。外部磁场的作用下可以增加纳米颗粒在目标生物体内的生物分布，例如癌瘤。因此，了解这些纳米颗粒的生物分布对于医学应用至关重要。它能够确定纳米颗粒是否被所需的器官捕获或在其他组织中积累，这可能导致潜在的毒性。这篇综述文章介绍了纳米颗粒积累的主要器官。它们最先吸收的部位通常是肝脏、脾脏和淋巴结，但通过适当的纳米颗粒设计，它们也可以在肺、心脏或大脑等器官积累。此外，综述还描述了影响纳米颗粒生物分布的因素，包括其大小、形状、表面电荷、涂层分子和给药途径。并介绍了确定分离组织或体内纳米颗粒积累部位和浓度的现代技术。© 2023 Nowak-Jary and Machnicka.

Magnetic iron oxide nanoparticles (magnetite and maghemite) are intensively studied due to their broad potential applications in medical and biological sciences. Their unique properties, such as nanometric size, large specific surface area, and superparamagnetism, allow them to be used in targeted drug delivery and internal radiotherapy by targeting an external magnetic field. In addition, they are successfully used in magnetic resonance imaging (MRI), hyperthermia, and radiolabelling. The appropriate design of nanoparticles allows them to be delivered to the desired tissues and organs. The desired biodistribution of nanoparticles, eg, cancerous tumors, is increased using an external magnetic field. Thus, knowledge of the biodistribution of these nanoparticles is essential for medical applications. It allows for determining whether nanoparticles are captured by the desired organs or accumulated in other tissues, which may lead to potential toxicity. This review article presents the main organs where nanoparticles accumulate. The sites of their first uptake are usually the liver, spleen, and lymph nodes, but with the appropriate design of nanoparticles, they can also be accumulated in organs such as the lungs, heart, or brain. In addition, the review describes the factors affecting the biodistribution of nanoparticles, including their size, shape, surface charge, coating molecules, and route of administration. Modern techniques for determining nanoparticle accumulation sites and concentration in isolated tissues or the body in vivo are also presented.© 2023 Nowak-Jary and Machnicka.