Department of Chemistry, Yonsei University, Seoul 120-749, Korea.
Acc Chem Res. 2011 Oct 18;44(10):863-74. doi: 10.1021/ar200085c. Epub 2011 Aug 8.
Early detection and treatment of disease is the most important component of a favorable prognosis. Biomedical researchers have thus invested tremendous effort in improving imaging techniques and treatment methods. Over the past decade, concepts and tools derived from nanotechnology have been applied to overcome the problems of conventional techniques for advanced diagnosis and therapy. In particular, advances in nanoparticle technology have created new paradigms for theranostics, which is defined as the combination of therapeutic and diagnostic agents within a single platform. In this Account, we examine the potential advantages and opportunities afforded by magnetic nanoparticles as platform materials for theranostics. We begin with a brief overview of relevant magnetic parameters, such as saturation magnetization, coercivity, and magnetocrystalline anisotropy. Understanding the interplay of these parameters is critical for optimizing magnetic characteristics needed for effective imaging and therapeutics, which include magnetic resonance imaging (MRI) relaxivity, heat emission, and attractive forces. We then discuss approaches to constructing an MRI nanoparticle contrast agent with high sensitivity. We further introduce a new design concept for a fault-free contrast agent, which is a T1 and T2 dual mode hybrid. Important capabilities of magnetic nanoparticles are the external controllability of magnetic heat generation and magnetic attractive forces for the transportation and movement of biological objects. We show that these functions can be utilized not only for therapeutic hyperthermia of cancer but also for controlled release of cancer drugs through the application of an external magnetic field. Additionally, the use of magnetic nanoparticles to drive mechanical forces is demonstrated to be useful for molecular-level cell signaling and for controlling the ultimate fate of the cell. Finally, we show that targeted imaging and therapy are made possible by attaching a variety of imaging and therapeutic components. These added components include therapeutic genes (small interfering RNA, or siRNA), cancer-specific ligands, and optical reporting dyes. The wide range of accessible features of magnetic nanoparticles underscores their potential as the most promising platform material available for theranostics.
早期发现和治疗疾病是预后良好的最重要组成部分。因此，生物医学研究人员投入了大量精力来改进成像技术和治疗方法。在过去的十年中，源自纳米技术的概念和工具已被应用于克服传统技术在高级诊断和治疗方面的问题。特别是，纳米颗粒技术的进步为治疗学创造了新的范例，即治疗和诊断剂在单个平台中的结合。在本报告中，我们检查了磁性纳米颗粒作为治疗学平台材料的潜在优势和机会。我们首先简要概述了相关的磁性参数，例如饱和磁化强度、矫顽力和磁晶各向异性。理解这些参数的相互作用对于优化有效成像和治疗所需的磁性特性至关重要，这些特性包括磁共振成像（MRI）弛豫率、热发射和吸引力。然后，我们讨论了构建具有高灵敏度的 MRI 纳米颗粒造影剂的方法。我们进一步介绍了一种新的无故障造影剂设计概念，这是一种 T1 和 T2 双模混合体。磁性纳米颗粒的重要功能是外部可控的磁热产生和生物物体运输和运动的磁性吸引力。我们表明，这些功能不仅可用于癌症的磁性热疗，还可用于通过施加外部磁场控制癌症药物的释放。此外，证明了使用磁性纳米颗粒来驱动机械力对于分子水平的细胞信号传导和控制细胞的最终命运是有用的。最后，我们表明通过附着各种成像和治疗组件可以实现靶向成像和治疗。这些附加组件包括治疗基因（小干扰 RNA 或 siRNA）、癌症特异性配体和光学报告染料。磁性纳米颗粒的广泛可访问特性突显了其作为治疗学最有前途的平台材料的潜力。
