New Concepts in Fluidics and Cellular Mechanics for Controlled Microinjection

受控显微注射流体学和细胞力学的新概念

• 批准号: 0828733
• 负责人: Tai-Hsi Fan
• 金额: $ 20万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-15 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0828733&HistoricalAwards=false
• 关键词: New; Concepts; Fluidics; Cellular; Mechanics

CBET-0828733FanMicroinjection is a well-accepted method to introduce matter such as sperm, nucleus, or solutes into biological cells for infertility treatment, transgenic and therapeutic cloning, or cryopreservation purposes. Millions of cellular microinjection operations for such applications and relevant biomedical research are conducted in the United States alone every year. The most utilized microinjection process is known as intracytoplasmic sperm injection as a part of the in vitro fertilization operation. The procedure consists of micropipette penetration through the egg cell's periphery including the zona pellucida and the plasma membrane, followed by the delivery of sperm for fertilization. To date, even with the help of piezo-assisted cell piercing device, the yield of microinjection process is undesirably low because the cells are easily damaged during the penetration and substance delivery, and subsequently causing abnormal growth. Furthermore, the success of the operation strongly depends on the operator's skill. Since the operating conditions are selected in an ad-hoc fashion, the results are often irreproducible at different laboratories or for different cells. To remedy these shortfalls, the PiIs team has recently developed a technology called the Rotationally Oscillating Drill which rotates the pipette via a micro-motor at very small angular strokes (e.g., 0.2 degrees) and at high frequencies (e.g., 500 Hz.). This operation is proven to be quite effective in the preliminary studies of the PI's group. This overarching goal cannot be achieved, however, without basic understanding of the complex microinjection process involving small-scale interactions between micropipettes and the soft biological cells in a fluid environment. The PI's objective is to resolve the transient micro-mechanical interfacial dynamics of the microinjection process and to monitor the rheological properties of the membrane of the oocytes. This fundamental understanding will establish scientific basis in determining the ideal operating conditions without lengthy trial-and-error studies. The research has two scientific thrusts: (i) Modeling the micro-dynamics while biological cells are pierced by highly flexible micropipettes. (ii) Developing optimal control protocols for our Ros-Drill microinjection process based on the insight gained from (i). The PIs will emphasize the basic understanding of small-scale and frequency-dependent material properties, fluid-pipette-membrane interactions, and the integration of nanoscopic capacitive force sensing devices. These crucial knowledge will potentially remove the dependence on human experience.If successful, the proposed study will introduce a revolutionary tool for cell biologists. This computer controlled microinjection technology (Ros-Drill) will have great potential to reduce the uncertainty and errors caused by human factors. It will increase the success rate (in injection) and reduce the number of tests on various species involved (in artificial insemination, cell surgery, and gene or drug delivery for therapeutic cloning purposes). The system will also integrate microscale force and position sensing devices, through which the experimental biologists will directly benefit from the emerging microelectromechanical systems technology. In addition to such fundamental scientific impact, the PIs plan on immediate dissemination of the findings in professional journals and at conferences. The PIs will also expand on a number of on-going outreach activities in K-12 education, in which we actively participate every year.

microinjection是一种被广泛接受的方法，可以将精子、细胞核或溶质等物质引入生物细胞中，用于不孕症治疗、转基因和治疗性克隆或冷冻保存。仅在美国，每年就有数百万例细胞显微注射手术用于此类应用和相关的生物医学研究。作为体外受精手术的一部分，最常用的显微注射过程被称为胞浆内单精子注射。该过程包括微移液管穿过卵细胞的外围，包括透明带和质膜，然后输送精子进行受精。迄今为止，即使有压电辅助细胞穿刺装置的帮助，由于细胞在穿透和物质输送过程中容易受损，从而导致异常生长，微注射过程的产量也很低。此外，操作的成功很大程度上取决于操作人员的技能。由于操作条件是临时选择的，因此在不同的实验室或不同的细胞中，结果往往是不可复制的。为了弥补这些不足，PiIs团队最近开发了一种名为旋转振荡钻的技术，该技术通过微电机以非常小的角冲程（例如0.2度）和高频率（例如500赫兹）旋转移液器。在PI小组的初步研究中，这种操作被证明是相当有效的。然而，如果不了解复杂的微注射过程，包括微移液管与软生物细胞在流体环境中的小规模相互作用，则无法实现这一总体目标。PI的目标是解决微注射过程的瞬态微力学界面动力学，并监测卵母细胞膜的流变特性。这种基本的理解将为确定理想的操作条件奠定科学基础，而无需进行冗长的试错研究。该研究有两个科学重点：(1)模拟生物细胞被高度灵活的微移液管刺穿时的微动力学。（ii）根据(i)获得的见解，为我们的Ros-Drill显微注射工艺制定最佳控制协议。课程将强调对小尺度和频率相关的材料特性、流体-移液管-膜的相互作用以及纳米级电容力传感装置的集成的基本理解。这些关键的知识将有可能消除对人类经验的依赖。如果成功，这项研究将为细胞生物学家引入一种革命性的工具。这种计算机控制的显微注射技术（Ros-Drill）在减少人为因素引起的不确定性和误差方面具有很大的潜力。它将提高成功率（注射）并减少对涉及的各种物种（人工授精、细胞手术和用于治疗性克隆的基因或药物输送）的试验次数。该系统还将集成微尺度力和位置传感装置，通过它，实验生物学家将直接受益于新兴的微机电系统技术。除了这些基本的科学影响外，pi还计划在专业期刊和会议上立即传播这些发现。我们每年都积极参与一些正在进行的K-12教育外展活动。