Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz, Iran.
Mater Sci Eng C Mater Biol Appl. 2013 Dec 1;33(8):4485-97. doi: 10.1016/j.msec.2013.07.012. Epub 2013 Jul 18.
Contrast agents are divided into two categories. The first one is paramagnetic compounds, including lanthanides like gadolinium, which mainly reduce the longitudinal (T1) relaxation property and result in a brighter signal. The second class consists of super-paramagnetic magnetic nanoparticles (SPMNPs) such as iron oxides, which have a strong effect on the transversal (T2) relaxation properties. SPMNPs have the potential to be utilized as excellent probes for magnetic resonance imaging (MRI). For instance, clinically benign iron oxide and engineered ferrite nanoparticles provide a good MRI probing capability for clinical applications. Furthermore, the limited magnetic property and inability to escape from the reticuloendothelial system (RES) of the used nanoparticles impede their further advancement. Therefore, it is necessary to develop the engineered magnetic nanoparticle probes for the next-generation molecular MRI. Considering the importance of MRI in diagnosing diseases, this paper presents an overview of recent scientific achievements in the development of new synthetic SPMNP probes whereby the sensitive and target-specific observation of biological events at the molecular and cellular levels is feasible.
对比剂分为两类。第一类是顺磁化合物，包括钆等镧系元素，主要降低纵向（T1）弛豫特性，从而产生更亮的信号。第二类由超顺磁的磁性纳米颗粒（SPMNPs）组成，如氧化铁，对横向（T2）弛豫特性有很强的影响。SPMNPs 有潜力成为磁共振成像（MRI）的优秀探针。例如，临床良性的氧化铁和工程铁氧体纳米颗粒为临床应用提供了良好的 MRI 探测能力。此外，所用纳米颗粒的有限磁性和无法逃避网状内皮系统（RES）限制了它们的进一步发展。因此，有必要开发用于下一代分子 MRI 的工程磁性纳米颗粒探针。鉴于 MRI 在疾病诊断中的重要性，本文综述了近年来在开发新型合成 SPMNP 探针方面的科学进展，通过这些探针可以在分子和细胞水平上实现对生物事件的敏感和靶向特异性观察。
