Single-molecule Force Microscopy: A Powerful Tool for Studying the Mechanical Properties of Cell Membranes

Abstract

Background: Cell membrane is a physical barrier for cells, as well as an important structure with complex functions in cellular activities. The cell membrane can not only receive external mechanical signal stimulation and respond (e.g., cell migration, differentiation, tumorigenesis, growth), but it can also spontaneously exert force on the environment to regulate cellular activities (such as tissue repair, tumor metastasis, extracellular matrix regulation, etc.). Methods: This review introduces single-molecule force methods, such as atomic force microscopy, optical tweezers, magnetic tweezers, micropipette adhesion assay, tension gauge tethers, and traction force microscopy. Results: This review summarizes the principles, advantages, and disadvantages of single-molecule force methods developed in recent years, as well as their application in terms of force received and generated by cells. The study of cell mechanics enables us to understand the nature of mechanical signal transduction and the manifestation of the cell's movement. Conclusion: The study of the mechanical properties of the cell microenvironment leads to a gradual understanding of the important role of cell mechanics in development, physiology, and pathology. Recently developed combined methods are beneficial for further studying cell mechanics. The optimization of these methods and the invention of new methods enable the continuing research on cell mechanics.