The article "The impact of extracellular matrix viscoelasticity on cellular behavior" by Ovijit Chaudhuri et al. reviews the significant impact of extracellular matrix (ECM) viscoelasticity on cellular processes such as spreading, growth, proliferation, migration, and differentiation. The authors highlight that while linearly elastic materials like polyacrylamide hydrogels and polydimethylsiloxane (PDMS) elastomers have been widely used to study the effects of stiffness on cells, tissues and ECMs exhibit complex mechanical behaviors, including viscoelasticity, mechanical plasticity, and nonlinear elasticity. Recent studies have shown that matrix viscoelasticity can promote behaviors not observed with elastic hydrogels in both 2D and 3D culture microenvironments, providing new insights into cell-matrix interactions and mechanotransduction. The article discusses the complex mechanical behaviors of tissues and ECMs, including viscoelasticity, poroelasticity, plasticity, and nonlinear elasticity. It explains how these properties affect cell behavior and highlights the importance of viscoelasticity in regulating development, homeostasis, regenerative processes, and disease progression. The authors also review the impact of matrix viscoelasticity on cell behavior in 2D and 3D culture, emphasizing the role of viscoelasticity in mechanical confinement and the dynamic nature of cell-matrix interactions. The article further explores the potential applications of viscoelastic biomaterials in regenerative medicine, suggesting that viscoelasticity is a key design parameter for biomaterials used in tissue engineering and organoid formation. It discusses the need for more measurements of viscoelasticity and viscoplasticity in various tissues and the potential therapeutic implications of understanding these properties in disease progression. Finally, the authors outline future research directions, including the need for more tools and approaches to study cell-matrix interactions in viscoelastic and viscoplastic matrices, and the importance of mimicking the mechanical characteristics of developing tissues in biomaterial design. They conclude that the advent of biomaterials with controlled viscoelasticity could be transformative in improving the success of biomaterials applications in regenerative medicine.The article "The impact of extracellular matrix viscoelasticity on cellular behavior" by Ovijit Chaudhuri et al. reviews the significant impact of extracellular matrix (ECM) viscoelasticity on cellular processes such as spreading, growth, proliferation, migration, and differentiation. The authors highlight that while linearly elastic materials like polyacrylamide hydrogels and polydimethylsiloxane (PDMS) elastomers have been widely used to study the effects of stiffness on cells, tissues and ECMs exhibit complex mechanical behaviors, including viscoelasticity, mechanical plasticity, and nonlinear elasticity. Recent studies have shown that matrix viscoelasticity can promote behaviors not observed with elastic hydrogels in both 2D and 3D culture microenvironments, providing new insights into cell-matrix interactions and mechanotransduction. The article discusses the complex mechanical behaviors of tissues and ECMs, including viscoelasticity, poroelasticity, plasticity, and nonlinear elasticity. It explains how these properties affect cell behavior and highlights the importance of viscoelasticity in regulating development, homeostasis, regenerative processes, and disease progression. The authors also review the impact of matrix viscoelasticity on cell behavior in 2D and 3D culture, emphasizing the role of viscoelasticity in mechanical confinement and the dynamic nature of cell-matrix interactions. The article further explores the potential applications of viscoelastic biomaterials in regenerative medicine, suggesting that viscoelasticity is a key design parameter for biomaterials used in tissue engineering and organoid formation. It discusses the need for more measurements of viscoelasticity and viscoplasticity in various tissues and the potential therapeutic implications of understanding these properties in disease progression. Finally, the authors outline future research directions, including the need for more tools and approaches to study cell-matrix interactions in viscoelastic and viscoplastic matrices, and the importance of mimicking the mechanical characteristics of developing tissues in biomaterial design. They conclude that the advent of biomaterials with controlled viscoelasticity could be transformative in improving the success of biomaterials applications in regenerative medicine.