Electromechanical Imaging of Live Vascular Smooth Muscle Cells

描述（由申请人提供）：电气和机械现象之间的耦合是所有生物系统的普遍特征。然而，对细胞和亚细胞尺度上的生物机电现象的起源知之甚少。了解潜在的分子机制可能会对生物过程和特定生物医学应用的一般理解产生巨大影响。细胞的机电刺激可以成为其表征的有价值的工具，并最终导致新的治疗干预的发展。 关于生物系统中的机电现象的信息不足是由于缺乏能够在纳米尺度上提供这种信息并且能够在液体环境中操作的表征技术。最近，压电响应力显微镜（PFM）已被证明有潜力的结缔组织和钙化组织的成像结构与亚10纳米的分辨率。该团队的成员还展示了水溶液中模型系统的高分辨率压电响应成像。在水介质中映射机电特性的能力开辟了在类似天然条件下表征生物系统的途径。 在这里，我们建议扩大PFM的表征和刺激的活细胞在生理环境中。我们的长期愿景是使用机电成像作为诊断工具，并最终利用机电刺激诱导细胞行为的理想变化。更具体地说，我们将专注于血管平滑肌细胞作为模型系统的机电特性。 为了完成这个计画的目标，我们将使用电子束诱导蚀刻来制作金属烤瓷冠成像所需的屏蔽探针，而探针是在生理浓度的电解质溶液中进行。我们将在水介质中对活的VSMCs进行PFM成像，并比较其合成和收缩表型的压电响应。作为这个项目的结果，我们希望开发实验技术，需要在活细胞中的局部机电现象的调查，并创建一个方法来预测机电刺激后的细胞行为。 公共卫生相关性声明：活细胞的机电成像可以成为一种独特的方法来提供有关细胞和组织在纳米尺度上的电生理反应的信息。它也可以在未来用于诊断目的。甚至更广泛地，设想使用活细胞的机电刺激可以在组织工程、医学诊断和生物传感中找到应用。

DESCRIPTION (provided by applicant): Coupling between electrical and mechanical phenomena is a universal feature of all biological systems. Yet, not much is known about origins of biological electromechanical phenomena on the cellular and subcellular scale. Understanding the underlying molecular mechanisms may have tremendous impact on general understanding of biological processes and specific biomedical applications. Electromechanical stimulation of cells can become a valuable tool for their characterization and can eventually result in the development of novel therapeutic interventions. Insufficient information about electromechanical phenomena in biological systems is a result of the lack of characterization techniques capable of providing such information on the nanometer scale and capable of operation in liquid environment. Recently, piezoresponse force microscopy (PFM) has demonstrated potential for imaging structure of connective and calcified tissues with sub-10 nm resolution. Members of this team have also demonstrated high resolution piezoresponse imaging of model systems in aqueous solutions. The ability to map electromechanical properties in aqueous media opens the way to characterization of biological systems in native-like conditions. Here we propose to expand PFM for characterization and stimulation of live cells in physiological environment. Our long-term vision is to use electromechanical imaging as a diagnostic tool and ultimately, utilize electromechanical stimulation for induction of a desirable change in cell behavior. More specifically, we will focus on electromechanical properties of vascular smooth muscle cells as a model system. To accomplish the goals of this project, we will use electron-beam induced etching to fabricate shielded probes needed for PFM imaging in electrolyte solutions with physiological concentrations. We will perform PFM imaging of live VSMCs in aqueous media and compare piezoresponce of their synthetic and contractile phenotypes. As a result of this project we expect to develop experimental technique needed for investigation of local electromechanical phenomena in live cells and create a methodology for predicting cell behavior upon electromechanical stimulation. Public Health Relevance Statement: Electromechanical imaging of live cells can become a unique method to provide information about electrophysiological response of cells and tissues on the nanoscale. It can also be used in the future for diagnostic purposes. Even more broadly, it is envisioned that the use of electromechanical stimulations of live cells can find applications in tissue engineering, medical diagnosis, and biosensing.