Department of Chemistry, University of Massachusetts, Amherst, MA, 01003, USA.
Department of Chemistry, University of Massachusetts, Amherst, MA, 01003, USA.
Anal Chim Acta. 2025 Jan 2;1333:343392. doi: 10.1016/j.aca.2024.343392. Epub 2024 Nov 4.
Cell-generated forces are a key player in cell biology, especially during cellular shape formation, migration, cancer development, and immune response. The measurement of forces exerted and experienced by cells is fundamental in understanding these mechanosensitive cellular behaviors. While cell-generated forces can now be detected based on techniques like fluorescence microscopy, atomic force microscopy, optical/magnetic tweezers, however, most of these approaches rely on complicated instruments or materials, as well as skilled operators, which could limit their potential broad applications in regular biological laboratories.
A new type of smartphone-based electrochemical sensor is developed here for cellular force measurement. In this system, a double-stranded DNA-based force probe, known as tension gauge tether, is attached to the surface of a gold screen-printed electrode, which is then incorporated into a portable smartphone-based electrochemical device. Cellular force-induced DNA detachment on the sensor surface results in multiple redox reporters to reach the surface of the electrode and generate enhanced electrochemical signals. To further improve the sensitivity, a CRISPR-Cas12a system has also been incorporated to cleave the remaining surface-attached anchor DNA strand. Using integrin-mediated tension as an example, piconewton-scale adhesion forces generated by ≤ 10 HeLa cells could now be reliably detected. Meanwhile, the threshold forces of these electrochemical sensors can also be modularly tuned to detect different levels of cellular forces.
These novel DNA-based highly sensitive, portable, cost-efficient, and easy-to-use electrochemical sensors can be potentially powerful tools for detecting different cell-generated molecular forces. Functioning as complementary tools with traction force microscopy and fluorescent probes, these electrochemical sensors can be straightforwardly applied in regular biological laboratories for understanding the basic mechanical principles of cell signaling and for developing novel strategies and materials in tissue engineering, regenerative medicine, and cell therapy.
细胞产生的力是细胞生物学的关键因素，尤其是在细胞形态形成、迁移、癌症发展和免疫反应过程中。测量细胞所施加和所受的力对于理解这些力敏细胞行为至关重要。尽管现在可以基于荧光显微镜、原子力显微镜、光学/磁性镊子等技术来检测细胞产生的力，但这些方法大多依赖于复杂的仪器或材料，以及熟练的操作人员，这可能限制了它们在常规生物实验室中的潜在广泛应用。
本文开发了一种基于智能手机的新型电化学传感器，用于细胞力测量。在该系统中，一种基于双链 DNA 的力探针，称为张力计系链，附着在金丝网印刷电极的表面，然后将其整合到便携式基于智能手机的电化学设备中。细胞力导致传感器表面上的 DNA 脱离，从而使多个氧化还原报告分子到达电极表面并产生增强的电化学信号。为了进一步提高灵敏度，还整合了 CRISPR-Cas12a 系统来切割剩余的表面附着的锚定 DNA 链。以整合素介导的张力为例，现在可以可靠地检测到≤10 个 HeLa 细胞产生的皮牛顿级粘附力。同时，这些电化学传感器的阈值力也可以模块化调节，以检测不同水平的细胞力。
这些新型基于 DNA 的高灵敏度、便携式、低成本、易于使用的电化学传感器有望成为检测不同细胞产生的分子力的强大工具。作为牵引力显微镜和荧光探针的补充工具，这些电化学传感器可以直接应用于常规生物实验室，以了解细胞信号转导的基本机械原理，并为组织工程、再生医学和细胞治疗开发新的策略和材料。
