Nanoparticle Probes for Super-Resolution Imaging of Transferrin Receptors

纳米颗粒是100纳米或更小的材料。纳米颗粒的行为不同于由相同材料制成的较大颗粒。研究纳米颗粒与生物材料(如活细胞)相互作用的能力受到限制，因为无法使用标准的显微镜方法观察它们。一种新型的纳米粒子可以发出闪烁的光，可以通过一种名为超分辨率显微镜的技术来观察纳米材料。这些纳米粒子将使研究人员能够在与活细胞和组织兼容的实验条件下，在没有复杂仪器的情况下实现超分辨率测量。这些纳米颗粒将被用来研究转铁蛋白受体在活细胞膜上的分布。转铁蛋白受体是一种蛋白质，它允许铁离子进入细胞，促进生长和正常功能。使用纳米颗粒了解转铁蛋白受体的分布将有助于揭示正常和异常的细胞生长，这对许多物种的组织发育具有重要意义。这项研究的结果将在生物医学工程、化学和生物学领域产生广泛影响。几名博士生和本科生将通过该项目接受培训，其中包括来自代表性不足群体的学生。纳米粒子与细胞和组织的相互作用仍然是生物工程中的一个基本问题。纳米颗粒与生物界面之间最重要的相互作用类型之一是受体标记。人转铁蛋白受体是参与细胞生长和增殖的关键受体。了解这种蛋白质在细胞表面的时空表达一直受到光的衍射限制和发光探针选择不当的限制。该项目旨在利用超分辨率显微镜扩大对荧光纳米颗粒探针与组织和细胞上转铁蛋白受体表达之间的相互作用的理解。为了实现这些目标，将开发一种新的纳米颗粒探头，用于在标准显微镜仪器上进行超分辨率显微镜观察。这些纳米粒子将是高度荧光的，并产生自我闪烁的行为。不需要光开关、复杂的光学装置或阻止体外使用的缓冲液。消除超分辨率的巨大技术障碍将把这种方法带到任何研究实验室，从而对任何需要化学信息和高空间分辨率的领域产生革命性的影响。闪烁的纳米颗粒，耦合到转铁蛋白受体配体，将被用来标记活细胞单层，以展示标准显微镜方法的超分辨率成像。成像转铁蛋白受体随时间的空间分布将为组织生长和一系列交叉生物过程提供新的线索。此外，还将研究配体结合纳米颗粒与生物界面的传输和结合，增加纳米材料与生物材料相互作用的知识。这项研究的结果将在生物医学工程、化学和生物学领域产生广泛影响。几名博士生和本科生将通过这个项目得到培训，其中包括来自代表性不足群体的学生。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Nanoparticles are materials that are 100 nanometers or smaller. The behavior of nanoparticles differs from larger particles made of the same materials. The ability to study nanoparticle interactions with biological materials, such as living cells, is limited by the inability to see them using standard microscopic methods. A new class of nanoparticles, which emit blinking light, can be used to observe nanomaterials through a technique called super-resolution microscopy. These nanoparticles will enable researchers to achieve super-resolution measurements without complex instruments, under experimental conditions that are compatible with living cells and tissues. These nanoparticles will be used to investigate the distribution of transferrin receptors on living cell membranes. Transferrin receptors are proteins that allow iron ions to be transported into cells to promote grown and normal function. Understanding the distribution of transferrin receptors using nanoparticles will shed light on normal and abnormal cell growth, which has implications in tissue development in many species. Results from this research will have broad impact in the fields of biomedical engineering, chemistry, and biology. Several doctoral and undergraduate students will be trained through this project, including students from underrepresented groups. Nanoparticle interactions with cells and tissues remain a fundamental question in bioengineering. One of the most important types of interactions between nanoparticles and biological interfaces is in receptor labeling. The human transferrin receptor is a key receptor implicated in cell growth and proliferation. Understanding the spatiotemporal expression of this protein on cell surfaces has been limited by the diffraction limit of light and poor choices of luminescent probes. This project seeks to broaden understanding of interactions between fluorescence nanoparticle probes and transferrin receptor expression on tissues and cells using super-resolution microscopy. To reach these goals, a new nanoparticle probe will be developed for super-resolution microscopy on standard microscopy instruments. These nanoparticles will be highly fluorescent and produce self-blinking behavior. No photoswitching, complex optics, or buffers that preclude in vitro use are needed. Eradicating the formidable technical barriers to super-resolution will bring this approach to any research lab, thus having a transformative impact on any field where chemical information and high spatial resolution are needed. Blinking nanoparticles, coupled to transferrin receptor ligands, will be used to label live cell monolayers to demonstrate super-resolution imaging with standard microscopy methods. Imaging the spatial distribution of transferrin receptors over time will shed new light on tissue growth and a host of cross-cutting biological processes. In addition, the transport and binding of ligand-conjugated nanoparticles with a biological interface will be studied, increasing knowledge in nanomaterial interactions with living materials. Results from this research will have broad impact in the fields of biomedical engineering, chemistry, and biology. Several doctoral and undergraduate students will be trained through this project, including students from underrepresented groups.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.