Electromechanical Imaging of Live Vascular Smooth Muscle Cells

描述(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，人们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表征细胞特性的有价值的工具，并最终可以导致新的治疗干预措施的发展。 关于生物系统中机电现象的信息不足是由于缺乏能够在纳米尺度上提供此类信息并能够在液体环境中运行的表征技术。近年来，压电响应力显微镜(PFM)显示出了在10 nm以下分辨率的结缔组织和钙化组织的成像结构的潜力。该团队的成员还展示了模型系统在水溶液中的高分辨率压电响应成像。绘制水介质中的机电属性图的能力为在类似自然的条件下表征生物系统开辟了道路。 在这里，我们建议扩展PFM来表征和刺激生理环境中的活细胞。我们的长期愿景是使用机电成像作为一种诊断工具，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，我们将重点研究血管平滑肌细胞的机电特性作为模型系统。 为了实现这个项目的目标，我们将使用电子束诱导腐蚀来制作在生理浓度的电解液中进行PFM成像所需的屏蔽探针。我们将在水介质中对活的VSMC进行PFM成像，并比较它们的合成表型和收缩表型的压电响应。作为这一项目的结果，我们希望开发研究活细胞中局部机电现象所需的实验技术，并创建一种预测细胞在机电刺激下的行为的方法学。 公共卫生相关声明：活细胞的机电成像可以成为在纳米尺度上提供细胞和组织电生理反应信息的独特方法。它还可以在未来用于诊断目的。更广泛地说，可以预见，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得到应用。

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.