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: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=588020
• 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对于生物过程和生物医学研究至关重要。目前许多用于细胞分析的仪器利用化学标记、精密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装置，为生物介质和无标记单细胞分析提供新工具。 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期、是健康的还是癌变的、或者药物是否已进入细胞并引发变化。几乎所有测量单个细胞介电特性的方法都在相对较低的频率（低于 100MHz）下采用基于阻抗谱或介电电泳的方法，其中外部质膜界面效应主导细胞的响应。通过将其扩展到微波频率，可以获得更多信息，在这种情况下，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，从而揭示有关细胞内特性的重要信息。由于单个生物细胞尺寸小，因此需要测量的信号也很小，因此对单个生物细胞进行微波介电光谱分析极其困难。该研究计划将探索基于介电泳和微波干涉的新方法，采用集成在微流控芯片中的分布式传输线，来测量单个细胞在宽带频率上的介电特性。 除了传感之外，还可以使用电子手段来刺激生物细胞。电穿孔是通过形成导电孔对生物细胞膜进行瞬时透化。根据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，或者在极端情况下，裂解。该研究的一个目标是开发在微流体生物芯片中实现的电子技术，用于应用高强度脉冲电场对单个细胞进行电穿孔，同时测量其介电响应。这将使研究细胞水平上的电穿孔过程和短时间尺度变化成为可能。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。我们将开发在纳秒范围内施加短持续时间脉冲的方法，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，从而提供了一种增强化疗药物有效性的方法。 研究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装置，提供新型非侵入式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对于集成到完整的芯片实验室平台非常有吸引力。