Viscoelasticity of ECM and cells-origin, measurement and correlation

The extracellular matrix (ECM) and cells are crucial components of natural tissue microenvironments, and they both demonstrate dynamic mechanical properties, particularly viscoelastic behaviors, when exposed to external stress or strain over time. The capacity to modify the mechanical properties of cells and ECM is crucial for gaining insight into the development, physiology, and pathophysiology of living organisms. As an illustration, researchers have developed hydrogels with diverse compositions to mimic the properties of the native ECM and use them as substrates for cell culture. The behavior of cultured cells can be regulated by modifying the viscoelasticity of hydrogels. Moreover, there is widespread interest across disciplines in accurately measuring the mechanical properties of cells and the surrounding ECM, as well as exploring the interactive relationship between these components. Nevertheless, the lack of standardized experimental methods, conditions, and other variables has hindered systematic comparisons and summaries of research findings on ECM and cell viscoelasticity. In this review, we delve into the origins of ECM and cell viscoelasticity, examine recently developed methods for measuring ECM and cell viscoelasticity, and summarize the potential interactions between cell and ECM viscoelasticity. Recent research has shown that both ECM and cell viscoelasticity experience alterations during in vivo pathogenesis, indicating the potential use of tailored viscoelastic ECM and cells in regenerative medicine.