School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Nat Nanotechnol. 2013 May;8(5):363-8. doi: 10.1038/nnano.2013.65. Epub 2013 May 5.
Silicon-based micro- and nanoparticles have gained popularity in a wide range of biomedical applications due to their biocompatibility and biodegradability in vivo, as well as their flexible surface chemistry, which allows drug loading, functionalization and targeting. Here, we report direct in vivo imaging of hyperpolarized (29)Si nuclei in silicon particles by magnetic resonance imaging. Natural physical properties of silicon provide surface electronic states for dynamic nuclear polarization, extremely long depolarization times, insensitivity to the in vivo environment or particle tumbling, and surfaces favourable for functionalization. Potential applications to gastrointestinal, intravascular and tumour perfusion imaging at subpicomolar concentrations are presented. These results demonstrate a new background-free imaging modality applicable to a range of inexpensive, readily available and biocompatible silicon particles.
基于硅的微纳米颗粒由于其在体内的生物相容性和生物降解性，以及其灵活的表面化学性质，允许药物负载、功能化和靶向，在广泛的生物医学应用中得到了广泛关注。在这里，我们报告了通过磁共振成像对硅颗粒中（29）硅核的超极化进行直接体内成像。硅的天然物理性质为动态核极化提供了表面电子态，具有极长的去极化时间，对体内环境或颗粒旋转不敏感，以及有利于功能化的表面。介绍了在亚皮摩尔浓度下用于胃肠道、血管内和肿瘤灌注成像的潜在应用。这些结果表明，一种新的无背景成像模式适用于一系列廉价、易得和生物相容的硅颗粒。
