Department of Physics, Harvard University, Cambridge, MA 02138, USA.
ACS Nano. 2009 Dec 22;3(12):4003-8. doi: 10.1021/nn900996p.
Magnetic resonance imaging of hyperpolarized nuclei provides high image contrast with little or no background signal. To date, in vivo applications of prehyperpolarized materials have been limited by relatively short nuclear spin relaxation times. Here, we investigate silicon nanoparticles as a new type of hyperpolarized magnetic resonance imaging agent. Nuclear spin relaxation times for a variety of Si nanoparticles are found to be remarkably long, ranging from many minutes to hours at room temperature, allowing hyperpolarized nanoparticles to be transported, administered, and imaged on practical time scales. Additionally, we demonstrate that Si nanoparticles can be surface functionalized using techniques common to other biologically targeted nanoparticle systems. These results suggest that Si nanoparticles can be used as a targetable, hyperpolarized magnetic resonance imaging agent with a large range of potential applications.
基于超极化核的磁共振成像是一种高对比度成像技术，背景信号很低或没有。迄今为止，预极化材料在体内的应用受到核自旋弛豫时间相对较短的限制。在这里，我们研究了硅纳米颗粒作为一种新型的超极化磁共振成像造影剂。结果发现，各种硅纳米颗粒的核自旋弛豫时间都非常长，在室温下从几分钟到几个小时不等，这使得超极化纳米颗粒能够在实际时间尺度内进行运输、给药和成像。此外，我们还证明了可以使用其他生物靶向纳米颗粒系统中常见的技术对硅纳米颗粒进行表面功能化。这些结果表明，硅纳米颗粒可用作一种有靶向性的超极化磁共振成像造影剂，具有广泛的潜在应用。
