Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zurich, Klingelbergstrasse 48, 4056, Basel, Switzerland.
Nanosurf AG, Gräubernstrasse 12, 4410, Liestal, Switzerland.
Nat Commun. 2024 Feb 26;15(1):1751. doi: 10.1038/s41467-024-46056-7.
The regulation of mass is essential for the development and homeostasis of cells and multicellular organisms. However, cell mass is also tightly linked to cell mechanical properties, which depend on the time scales at which they are measured and change drastically at the cellular eigenfrequency. So far, it has not been possible to determine cell mass and eigenfrequency together. Here, we introduce microcantilevers oscillating in the Ångström range to monitor both fundamental physical properties of the cell. If the oscillation frequency is far below the cellular eigenfrequency, all cell compartments follow the cantilever motion, and the cell mass measurements are accurate. Yet, if the oscillating frequency approaches or lies above the cellular eigenfrequency, the mechanical response of the cell changes, and not all cellular components can follow the cantilever motions in phase. This energy loss caused by mechanical damping within the cell is described by the quality factor. We use these observations to examine living cells across externally applied mechanical frequency ranges and to measure their total mass, eigenfrequency, and quality factor. The three parameters open the door to better understand the mechanobiology of the cell and stimulate biotechnological and medical innovations.
质量的调节对于细胞和多细胞生物的发育和动态平衡至关重要。然而，细胞质量也与细胞力学性质紧密相关，后者取决于测量的时间尺度，并在细胞固有频率处发生剧烈变化。到目前为止，还不可能同时确定细胞质量和固有频率。在这里，我们引入了在埃范围内振荡的微悬臂梁来监测细胞的基本物理性质。如果振荡频率远低于细胞固有频率，所有细胞隔室都跟随微悬臂梁的运动，并且细胞质量测量是准确的。然而，如果振荡频率接近或高于细胞固有频率，细胞的力学响应就会发生变化，并非所有细胞成分都能与微悬臂梁同步运动。这种细胞内机械阻尼引起的能量损失由品质因数来描述。我们利用这些观察结果在外部施加的机械频率范围内研究活细胞，并测量它们的总质量、固有频率和品质因数。这三个参数为更好地理解细胞的机械生物学打开了大门，并激发了生物技术和医学创新。
