Microwave Devices for Biosensors and Single Cell Analysis

用于生物传感器和单细胞分析的微波设备

• 批准号: RGPIN-2014-04796
• 负责人: Bridges, Greg
• 金额: $ 2.7万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611247
• 关键词: Microwave; Devices; Biosensors; Single; Cell

Studying the physiology of normal and diseased biological cells and monitoring their response to different stimuli or drugs is essential in bioprocess and biomedical research. Many currently used instruments for cellular analysis utilize chemical markers, sophisticated equipment and time-consuming preparation techniques. Electronic based analysis approaches are a promising alternative. The objective of this research program is to develop microfluidics devices integrated with microwave dielectric sensors and high-frequency electric field stimulus to provide new tools for biological media and label-free single cell analysis. Tissues, cells and other biomedia have unique dielectric properties that, if measured, can be used to provide a wealth of information. For example, by monitoring the dielectric state of a biological cell, it can be determined whether it is in a particular growth phase, whether it is healthy or cancerous, or if drugs have entered the cell and initiated changes. Almost all methods for measuring the dielectric properties of a single cell have employed impedance spectroscopy or dielectrophoresis based approaches at relatively low frequencies, below 100MHz, where outer plasma membrane interfacial effects dominate the cell’s response. There is additional information that can be gained by extending this to microwave frequencies, a regime where fields can penetrate the cell interior and organelles and the polarizability of large molecules can be detected, revealing important information on intracellular properties. Microwave dielectric spectroscopic analysis of single biological cells is extremely difficult due to their small size and thus small signals that have to be measured. This research program will explore new dielectrophoresis based and microwave interferometric-based methods, employing distributed transmission lines integrated in a microfluidic chip, to measure the dielectric properties of single cells over a wideband of frequencies. Besides sensing, electronic means can be used to stimulate biological cells. Electroporation is the transient permeabilization of a biological cell membrane, through the formation of conductive pores. Depending on the intensity and duration of the applied field, electroporation can be used to reversibly or irreversibly permeabilize the membrane, enabling transfection, enhancing drug uptake in cancer therapy, inducing programmed cell death, or in the extreme case, lysis. An objective of the research is to develop electronic techniques, implemented in a microfluidic biochip, for applying high-intensity pulsed electric fields to electroporate single cells while simultaneously measuring their dielectric response. This will enable studying the electroporation process and short timescale changes at the cellular level. Electroporation is usually performed using millisecond-to-microsecond pulsed electric fields, where only the outer membrane of the cell is permeabilized. We will develop methods for applying short duration pulses, in the nanosecond regime, where the electric field can penetrate inside the cell. Access to the interior of the cell has the potential for selective electroporation of its organelles, providing a means to enhance the effectiveness of drugs in chemotherapy for example. The outcomes of the research will be all-electronic microfluidic devices integrated with microwave dielectric spectroscopy and high-frequency electric field stimulus capabilities, providing new non-invasive label-free single cell analysis instruments. The ability to perform measurements using nanoliter volumes in an all-electronic manner make this very attractive for integration into a complete lab-on-chip platform.

研究正常和患病生物细胞的生理学并监测它们对不同刺激或药物的反应在生物过程和生物医学研究中是必不可少的。许多目前使用的细胞分析仪器利用化学标记物、复杂的设备和耗时的制备技术。基于电子的分析方法是一种有前途的替代方法。该研究计划的目标是开发集成微波介电传感器和高频电场刺激的微流体设备，为生物介质和无标记单细胞分析提供新的工具。 组织、细胞和其他生物介质具有独特的介电特性，如果对其进行测量，可用于提供丰富的信息。例如，通过监测生物细胞的介电状态，可以确定它是否处于特定的生长阶段，它是健康的还是癌变的，或者药物是否已经进入细胞并引发变化。几乎所有用于测量单个细胞的介电性质的方法都在相对低的频率（低于100MHz）下采用基于阻抗谱或介电电泳的方法，其中外质膜界面效应主导细胞的响应。通过将其扩展到微波频率可以获得额外的信息，在这种频率下，场可以穿透细胞内部和细胞器，并且可以检测大分子的极化率，从而揭示关于细胞内特性的重要信息。单个生物细胞的微波介电光谱分析是非常困难的，因为它们的尺寸很小，因此必须测量的信号很小。该研究计划将探索新的基于介电电泳和微波干涉的方法，采用集成在微流控芯片中的分布式传输线，以测量单细胞在宽带频率上的介电特性。 除了传感，电子手段可以用来刺激生物细胞。电穿孔是生物细胞膜的瞬时透化，通过形成导电孔。根据所施加场的强度和持续时间，电穿孔可用于可逆或不可逆地透化膜，从而实现转染，增强癌症治疗中的药物摄取，诱导程序性细胞死亡，或在极端情况下，裂解。该研究的一个目标是开发电子技术，在微流体生物芯片中实现，用于施加高强度脉冲电场电穿孔单细胞，同时测量其介电响应。这将使研究电穿孔过程和短时间尺度的变化在细胞水平上。电穿孔通常使用毫秒至微秒的脉冲电场进行，其中仅细胞的外膜被透化。我们将开发应用纳秒级短脉冲的方法，其中电场可以穿透细胞内部。进入细胞内部有可能对其细胞器进行选择性电穿孔，从而提供了一种提高药物有效性的方法，例如化疗。 该研究的成果将是集成微波介电谱和高频电场刺激能力的全电子微流控设备，提供新的非侵入性无标记单细胞分析仪器。以全电子方式使用纳升体积进行测量的能力使其非常适合集成到完整的芯片实验室平台中。