Robotic Micromanipulation and Mechanical Characterization of Intracellular Structures

细胞内结构的机器人微操作和机械表征

• 批准号: RGPIN-2018-06061
• 负责人: Sun, Yu
• 金额: $ 8.41万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=714060
• 关键词: Robotic; Micromanipulation; Mechanical; Characterization; Intracellular

The past two decades have seen strides in single-cell manipulation and measurement. This research will go beyond the state of the art to develop a transformative platform technology for 3D manipulation and mechanical measurement inside a cell. The new platform and techniques will enable 3D navigation of a sub-micron magnetic bead (and later more sophisticated magnetic devices) inside a cell to perform mechanical measurements, which will open an exciting new era of intracellular physical measurement and manipulation. The near-term objectives include: Aim 1: Establish a new robotic magnetic tweezers platform for 3D intracellular navigation and measurement; Aim 2: Develop new magnetic force models and force/position control methods for controlling a sub-micron magnetic bead with 3D confocal microscopy image feedback; Aim 3: Perform mechanical measurements at different locations on the cell nucleus in an intact cell to quantify stiffness heterogeneity along different directions of the cell nucleus. To achieve these goals, we will develop a new multi-pole magnetic tweezers platform and technologies to manipulate a sub-micron magnetic bead and tackle the challenges of low-bandwidth high-resolution visual feedback, sub-micron position control, and picoNewton force control. Specifically, we will pursue 3D magnetic tweezers platform design, construction, analytical modeling, numerical simulation, system testing/debugging, and optimization. We will establish nonlinear magnetic field models that relate driving currents to magnetic field generation and quantify force application. Magnetic field simulation will also be conducted to calculate magnetic forces exerted on the sub-micron magnetic bead. Calibration experiments will be performed and position-force errors will be quantified among experimental results and results from analytical modeling and finite element simulation for each point in the workspace. Generalized predictive controllers based on bead dynamics will be developed to position a sub-micron bead to different locations on the cell nucleus in an intact cell to indent the cell nucleus at varying speeds. Experimental data will be analyzed with mechanics models to generate a stiffness/modulus/viscosity map for each measured location on the cell nucleus at different stages of cancer cell development. Polarity of mechanical properties along the major and minor axes of the cell nucleus, force-induced stiffening of the softer axis, and alteration of the migratory behavior of cancer cells will be measured. The necessity of mechanical polarity of the cell nucleus for cancer cell migration will be unequivocally demonstrated. This research program will train HQP to pursue research careers in NSE or fulfill the great demand of Canadian instrumentation and biotech industries.

在过去的二十年中，在单细胞的操作和测量中取得了长足的进步。这项研究将超越最新技术，以开发一种用于3D操纵和机械测量的变革性平台技术。新的平台和技术将使3D导航能够在单元格内进行次级微米磁珠（后来更复杂的磁性设备）进行机械测量，这将打开一个令人兴奋的细胞内物理测量和操作的新时代。 近期目标包括：目标1：建立一个新的机器人磁镊子平台，用于3D细胞内导航和测量；目标2：开发新的磁力模型和力/位置控制方法，用于控制具有3D共聚焦显微镜图像反馈的亚微米磁珠； AIM 3：在完整细胞中的细胞核上的不同位置进行机械测量，以量化细胞核不同方向的刚度异质性。为了实现这些目标，我们将开发一个新的多极磁镊子平台和技术来操纵亚微米磁珠，并应对低型带宽高分辨率高分辨率视觉反馈，亚微米位置控制和Piconewton力量控制的挑战。具体来说，我们将追求3D磁性镊子平台设计，构建，分析建模，数值模拟，系统测试/调试和优化。我们将建立非线性磁场模型，将驱动电流与磁场生成并量化力应用。还将进行磁场模拟以计算施加在亚微米磁珠上的磁力。将进行校准实验，并将在工作空间中每个点的分析建模和有限元仿真的结果之间量化位置误差。 将开发基于珠子动力学的广义预测控制器，以将亚微米珠定位在完整细胞中细胞核上的不同位置，以使细胞核以不同速度的速度缩小。将使用力学模型分析实验数据，以生成在癌细胞发育不同阶段的细胞核上每个测得的位置的刚度/模量/粘度图。将测量机械性能沿细胞核的主要和次要轴的极性，力诱导的轴轴的僵硬以及癌细胞迁移行为的改变。细胞核的机械极性对癌细胞迁移的必要性将被明确证明。该研究计划将培训HQP从事NSE的研究职业，或满足加拿大仪器和生物技术行业的巨大需求。