Department of Materials Science & Engineering, University of Washington, Seattle, WA, 98195, USA.
Adv Mater. 2021 Jun;33(23):e1906539. doi: 10.1002/adma.201906539. Epub 2020 Jun 4.
Gadolinium-based chelates are a mainstay of contrast agents for magnetic resonance imaging (MRI) in the clinic. However, their toxicity elicits severe side effects and the Food and Drug Administration has issued many warnings about their potential retention in patients' bodies, which causes safety concerns. Iron oxide nanoparticles (IONPs) are a potentially attractive alternative, because of their nontoxic and biodegradable nature. Studies in developing IONPs as T contrast agents have generated promising results, but the complex, interrelated parameters influencing contrast enhancement make the development difficult, and IONPs suitable for T contrast enhancement have yet to make their way to clinical use. Here, the fundamental principles of MRI contrast agents are discussed, and the current status of MRI contrast agents is reviewed with a focus on the advantages and limitations of current T contrast agents and the potential of IONPs to serve as safe and improved alternative to gadolinium-based chelates. The past advances and current challenges in developing IONPs as a T contrast agent from a materials science perspective are presented, and how each of the key material properties and environment variables affects the performance of IONPs is assessed. Finally, some potential approaches to develop high-performance and clinically relevant T contrast agents are discussed.
镧系螯合物是临床磁共振成像（MRI）造影剂的主要成分。然而，其毒性会引发严重的副作用，美国食品和药物管理局已多次发出警告，称其可能在患者体内蓄积，引起安全问题。氧化铁纳米粒子（IONPs）由于其无毒和可生物降解的特性，是一种很有吸引力的替代品。将 IONPs 开发为 T 造影剂的研究已经取得了有希望的结果，但影响对比增强的复杂、相互关联的参数使得开发变得困难，适合 T 对比增强的 IONPs 尚未进入临床应用。本文讨论了 MRI 造影剂的基本原理，并回顾了 MRI 造影剂的现状，重点介绍了当前 T 造影剂的优势和局限性，以及 IONPs 作为基于镧系螯合物的安全且改良替代品的潜力。从材料科学的角度介绍了将 IONPs 开发为 T 造影剂的过去进展和当前挑战，并评估了每个关键材料特性和环境变量如何影响 IONPs 的性能。最后，讨论了一些开发高性能和临床相关 T 造影剂的潜在方法。
