Electron Spin Resonance Microfluidics as a new tool in chemical single cell population analysis

摘要 单细胞分析是现代生物和医学研究中的一种变革性能力，它使 捕捉整个细胞群体内细胞之间的异质性。单细胞分析可以检测到 单细胞水平的生物、化学和物理化学参数。虽然有无数的 单细胞分析、磁共振，特别是电子自旋共振(ESR)的分析方法， 尚未对这一领域做出贡献，主要是因为敏感性问题和缺乏适当的生物稳定性 细胞内自旋探针。该提案旨在开发一种高灵敏度的基于ESR的流式细胞术技术 (仪器和分子自旋探针)，使单细胞化学和物理化学分析成为可能 参数。目前的项目重点是同时测量氧分压和微粘度。 单细胞水平的发展和演示的概念。然而，这项技术可以应用于评估 其他参数，如微粘度、pH、氧浓度、氧化还原状态和谷胱甘肽。 我们将通过以下三个具体目标来实现我们的目标。在SA1中，我们将合成并表征 细胞内生物稳定的三叔丁基自旋探针对氧浓度和微粘度敏感。在SA2中，我们将 开发一种紧凑、高灵敏度的ESR表面谐振器，嵌入细胞微流控设备中，用于测量 单细胞的连续流动。最后，在SA3中，我们将通过单细胞测量来验证我们的技术 对于一个癌细胞系中几百个细胞的群体。这个R21项目的完成将扩大 当前的单细胞分析能力，允许评估不能完全完成的多个参数 以当前可用的技术为特征，并在下游有重要的新应用。

ABSTRACT Single-cell analysis is a transformative capability in modern biological and medical research that enables capturing the heterogeneity between cells within an entire cell population. Single-cell analysis can inspect biological, chemical, and physicochemical parameters at the single-cell level. While there are numerous analytical approaches to single-cell analysis, magnetic resonance and especially electron spin resonance (ESR), is yet to contribute to this field, mostly because of a sensitivity issue and the lack of appropriate bio-stable intracellular spin probes. This proposal aims to develop a highly sensitive ESR-based flow cytometry technology (instrumentation and molecular spin-probes) that enables single-cell analysis of chemical and physicochemical parameters. The current project focuses on the simultaneous measurement of pO2 and microviscosity at the single-cell level to develop and demonstrate the concept. However, the technology can be applied to assess other parameters in the future, such as microviscosity, pH, oxygen concentration, redox status, and glutathione. We will achieve our goal by the following three specific aims. In SA1, we will synthesize and characterize intracellular biostable trityl spin probes sensitive to the oxygen concentration and microviscosity. In SA2, we will develop a compact, highly sensitive ESR surface resonator embedded in a cell microfluidic device to measure a continuous flow of single cells. Finally, in SA3, we will validate our technology with the single-cell measurement for a population of a few hundred cells of a cancer cell line. The completion of this R21 project will expand the current capability in single-cell analysis, allowing assessing multiple parameters that cannot be fully characterized by the currently available techniques with significant new applications downstream.