Collaborative Research Optical and Dynamic Nuclear Polarization Approaches to Hyperpolarization of Nanoparticles for Molecular Imaging

用于分子成像的纳米粒子超极化的光学和动态核极化方法的合作研究

• 批准号: 0932985
• 负责人: Ronald Walsworth
• 金额: $ 30万
• 依托单位: Smithsonian Institution Astrophysical Observatory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0932985&HistoricalAwards=false
• 关键词: Collaborative; Research; Optical; Dynamic; Nuclear

0932985Walsworth"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."The overall goal of the proposed research is to functionalize Si nanoparticles to target common cancers, enhance the NMR signal of these particles using dynamic nuclear polarization (DNP), and characterize the hyperpolarized particles in vitro. These are vital steps toward our overall objective of developing a novel molecular imaging probe based on MRI of hyperpolarized silicon nanoparticles, to provide a novel tool for measuring and imaging biological processes in health and disease. The use of hyperpolarized noble gases for lung imaging has clearly demonstrated the benefits of imaging hyperpolarized agents, providing both dramatically increased detection sensitivity as well as eliminating all background signals. Recently, 13C imaging of 13C-hyperpolarized metabolites has provided a method for rapid metabolic profiling. However, the very short nuclear relaxation times of hyperpolarized agents used, typically less than 60 s for most 13C agents, is much too short for the imaging of targeted molecular probes that require several hours to both reach and bind their targets. The investigators have demonstrated that Si nanoparticles can be surface-coated, have their polarization enhanced by over three of orders of magnitude compared to room temperature Boltzmann polarization, and that the 29Si nanoparticle spins can exhibit nuclear relaxation times 500 s. Investigators have also shown that this relaxation time can be tailored for the application by modifying particle size. The present proposal focuses on functionalization of the nanoparticles to target common cancer cells and efforts to maximize and retain the hyperpolarization of the Si nanoparticles during delivery. Such 29Sibased imaging agents will provide powerful and much needed new tools for targeted molecular imaging, cell tracking and the detection of tumors. The proposal consists of three specific aims. The first aim is to develop targetable Si nanoparticles that can be hyperpolarized; the second aim is to develop high efficiency dynamic nuclear polarization; the third aim is to perform standard NMR and MRI on the functionalized nanoparticles, before and after hyperpolarization.

0932985Walsworth“该奖项是根据 2009 年美国复苏和再投资法案（公法 111-5）资助的。”拟议研究的总体目标是功能化硅纳米颗粒以靶向常见癌症，使用动态增强这些颗粒的 NMR 信号核极化（DNP），并在体外表征超极化粒子。这些是实现我们开发基于超极化硅纳米粒子 MRI 的新型分子成像探针的总体目标的重要步骤，为健康和疾病的生物过程提供测量和成像的新工具。使用超极化惰性气体进行肺部成像已经清楚地证明了超极化试剂成像的好处，可以显着提高检测灵敏度并消除所有背景信号。最近，13C 超极化代谢物的 13C 成像提供了一种快速代谢分析的方法。然而，所使用的超极化试剂的核弛豫时间非常短，对于大多数 13C 试剂来说通常小于 60 秒，对于需要几个小时才能到达并结合目标的靶向分子探针的成像来说太短了。研究人员证明，Si 纳米颗粒可以进行表面涂覆，其偏振度比室温玻尔兹曼偏振增强三个数量级以上，并且 29Si 纳米颗粒自旋可以表现出 500 秒的核弛豫时间。研究人员还表明，可以通过改变颗粒尺寸来调整弛豫时间以适应应用。目前的提案重点关注纳米颗粒的功能化，以靶向常见的癌细胞，并努力在输送过程中最大化和保留硅纳米颗粒的超极化。这种基于 29Si 的成像剂将为靶向分子成像、细胞追踪和肿瘤检测提供强大且急需的新工具。该提案包含三个具体目标。第一个目标是开发可超极化的可靶向硅纳米颗粒；第二个目标是开发高效动态核极化；第三个目标是在超极化之前和之后对功能化纳米颗粒进行标准 NMR 和 MRI。