Viscoelastic properties of human mesenchymal stem cells.

In this study, we investigated the viscoelasticity of individual bone marrow-derived adult human mesenchymal stem cells (hMSCs), and the role of specific cytoskeletal component-F-actin microfilaments on the mechanical properties of individual hMSCs. The mechanical properties of hMSCs were determined using the micropipette aspiration technique coupled with a viscoelastic solid model of the cell. For the hMSCs under control conditions the instantaneous Young's modulus E₀ was found to be 886plusmn289(Pa), the equilibrium Young's modulus E_infin 372plusmn125(Pa), and the apparent viscosity mu 2714plusmn1626(Pamiddots). After exposed to 2muM of chemical agent-cytochalasin D that disrupt the F-actin microfilaments, the Young's moduli of hMSCs decreased by up to 72% and the apparent viscosity increased by 167%. These findings suggest that microfilaments are crucial in providing the viscoelastic properties of the hMSCs, and changes in the structure and properties of them may influence the mechanical properties of hMSCs significantly.