CAREER: Nanoscale sensing and imaging using computational single-molecule nanoscopy

职业：使用化学探针、计算和显微镜可视化细胞膜中单个分子之间的相互作用细胞的膜将其内部内容物(如细胞器、DNA和蛋白质)从环境中分离出来，从而控制化学信号(例如分子)如何发送到其他细胞和从其他细胞接收。由于这些膜的小尺寸和快速波动，现有的成像技术难以直观地显示这些膜的纳米级“皱纹”和粗糙度。该项目将开发一种名为计算单分子纳米显微镜的协同方法，将光学硬件、图像处理软件和分子传感器结合在一起，以纳米级分辨率成像活细胞。这项拟议的技术将可视化控制其工作方式的膜内的电气和化学环境。最终，这种方法将使科学家能够研究膜内的纳米结构如何影响分子通过膜的运输方式，这可能有助于靶向和杀死癌细胞的纳米药物的设计。国际和平研究所将与圣路易斯科学中心和华盛顿大学光谱学生团体合作，促进公众对这项研究的科学和技术理解。参与研究计划的本科生和研究生将在应用物理、光学、光谱学、估计理论、图像处理和生物学方面获得广泛的知识和不同的技术技能。这些学生将接受独特和全面的现代职业生涯的技术创新和科学发现的准备。拟议的研究将开发一种集成的化学、光学和计算技术，称为计算单分子纳米显微镜，用于以纳米级分辨率传感和成像细胞膜的电学和化学性质。研究方法是1)调查用于测量纳米级信息的计算光学纳米显微镜的分辨率和灵敏度极限；2)量化荧光分子用于传感其纳米环境的电学和化学性质的性能；以及3)可视化细胞膜内的脂筏，以确定它们如何调节生物分子在膜上的运输。这项工作的优点在于创新性地利用了荧光分子和光学显微镜之间的协同作用。不像目前的方法那样，简单地使用荧光分子作为报告生物分子位置的信标，快速扩散的分子发出的荧光将被用来测量纳米环境的极性和流动性。为了利用这些分子报告的信息，将联合设计新的光学系统和图像处理算法，以在存在噪声的情况下最大限度地提高纳米级测量的精度和灵敏度。检测细胞膜的纳米尺度特性将提供对细胞间通信的新见解：电、化学和机械信号如何在细胞之间和跨细胞膜传播。

CAREER: Visualizing the Interactions between Individual Molecules within Cell Membranes Using Chemical Probes, Computation, and MicroscopyThe membrane of a cell separates its internal contents, such as organelles, DNA, and proteins, from its environment and therefore controls how chemical signals (e.g., molecules) are sent to and received from other cells. Existing imaging technologies struggle to visualize the nanoscale "wrinkles" and roughness of these membranes due to their small sizes and fast fluctuations. This project will develop a synergistic approach called computational single-molecule nanoscopy that combines optical hardware, image processing software, and molecular sensors for imaging living cells with nanoscale resolution. The proposed technology will visualize the electrical and chemical environments within membranes that govern how they work. Ultimately, this approach will enable scientists to study how nanoscale structures within the membrane influence how molecules are transported across the membrane, which could be useful for the design of nanomedicines that target and kill cancer cells. The PI will collaborate with the Saint Louis Science Center and the Washington University SPECTRA student group to promote the public's scientific and technological understanding of this research. Undergraduate and graduate students involved in the research program will obtain broad knowledge and diverse technical skills in applied physics, optics, spectroscopy, estimation theory, image processing, and biology. These students will receive a unique and comprehensive preparation for modern careers in technology innovation and scientific discovery.The proposed research will develop an integrated chemical, optical, and computational technology, termed computational single-molecule nanoscopy, for sensing and imaging the electrical and chemical properties of cell membranes with nanoscale resolution. The research approach is 1) to investigate the resolution and sensitivity limits of computational optical nanoscopy for measuring nanoscale information; 2) to quantify the performance of fluorescent molecules for sensing the electrical and chemical properties of their nano-environments; and 3) to visualize lipid rafts within cell membranes to determine how they regulate the trafficking of biomolecules across the membrane. The merit of the proposed work lies in innovatively exploiting the synergy between fluorescent molecules and optical microscopes. Rather than simply using fluorescent molecules as beacons that report a biomolecule's location, as current methods do now, the fluorescence emitted by rapidly-diffusing molecules will be used to measure the polarity and fluidity of a nano-environment. To harness the information reported by these molecules, new optical systems and image processing algorithms will be jointly designed to maximize the precision and sensitivity of nanoscale measurements in the presence of noise. Sensing the nanoscale properties of cell membranes will provide new insight into intercellular communication: how electrical, chemical, and mechanical signals propagate between cells and across their membranes.