基于磷化铁纳米颗粒的新型磁共振成像造影剂的合成及造影性能评价

Magnetic resonance imaging (MRI) contrast agents with the ability to shorten relaxation time of tissue protons can greatly improve the accuracy and specificity of MRI. Therefore, the search for novel MRI contrast agents is desirable and of great importance. Iron phosphide has unique magnetic properties, depending on its phase, it can exhibit a paramagnetic (e.g., FeP) or ferromagnetic (e.g., Fe2P and Fe3P) behavior at room temperature, thus holds great promise in serving as novel MRI contrast agents. In this project, to confirm the potential of iron phosphide nanoparticles in serving as novel MRI contrast agents, the interplay between phase (FeP, Fe2P and Fe3P) and MRI contrast abilities in iron phosphide nanoparticles and the biocompatibility of iron phosphide nanoparticles will be comprehensively investigated. These investigations may not only provide new strategies to achieve novel MRI contrast agents, but also may help to better understand the mechanism of T1 and T2 shortening of magnetic nanoparticle-based MRI contrast agents.

磁共振成像造影剂可以改变组织的弛豫时间，从而改变组织的信号强度，有力地提高了组织的影像对比度，使得诊断更准确。因此，发展新型磁共振成像造影剂具有重要的现实意义。磷化铁具有独特的磁学性质，依据晶相的不同在室温下可表现为顺磁性（如FeP）或铁磁性（如Fe3P和Fe2P），因此具有作为新型磁共振成像造影剂的巨大潜能。本项目以磷化铁纳米颗粒为研究对象，考察其晶相（FeP、Fe2P和Fe3P）与磁共振造影性能之间的相互关系，并系统评价其生物安全性，以探讨磷化铁纳米颗粒作为新型磁共振造影剂的可行性。本项目的实施不仅可以丰富新型磁共振成像造影剂的获得，而且还可为进一步理解磁性纳米颗粒的磁共振造影机理提供一定的参考。

磁共振成像造影剂可以改变组织的弛豫时间，从而改变组织的信号强度，有力地提高了组织的影像对比度，使得诊断更准确。因此，发展新型磁共振成像造影剂具有重要的现实意义。在项目的资助下，项目组合成了超小粒径（<5 nm）的磷化铁纳米颗粒，发现其在肿瘤酸性微环境下可以释放出顺磁性铁离子，从而增强T1加权成像信号，可作为潜在的酸响应磁共振成像造影剂。此外，项目组还开发了其他一系列基于无机纳米材料的新型磁共振造影剂及肿瘤诊疗一体化纳米系统。通过项目的实施，项目发表SCI期刊论文9篇，申请专利1项。