Viscoelastic behaviour of human mesenchymal stem cells.
BACKGROUND
In this study, we have investigated the viscoelastic behaviour of individual human adult bone marrow-derived mesenchymal stem cells (hMSCs) and the role of F-actin filaments in maintaining these properties, using micropipette aspiration technique together with a standard linear viscoelastic solid model.


RESULTS
Under a room temperature of 20 degrees C, the instantaneous and equilibrium Young's modulus, E0 and Einfinity, were found to be 886 +/- 289 Pa and 372 +/- 125 Pa, respectively, while the apparent viscosity, mu, was 2710 +/- 1630 Pa.s. hMSCs treated with cytochalasin D up to 20 microM at 20 degrees C registered significant drop of up to 84% in stiffness and increase of up to 255% in viscosity. At the physiological temperature of 37 degrees C, E0 and Einfinity have decreased by 42-66% whereas mu has increased by 95%, compared to the control. Majority of the hMSCs behave as viscoelastic solid with a rapid initial increase in aspiration length and it gradually levels out with time. Three other types of non-typical viscoelastic behavior of hMSCs were also seen.


CONCLUSIONS
hMSCs behave as viscoelastic solid. Its viscoelstic behaviour are dependent on the structural integrity of the F-actin filaments and temperature.
Tan
Samuel C W
SC
Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457, Singapore. tanc0101@ntu.edu.sg
Pan
Wen X
WX
Ma
Gang
G
Cai
Ning
N
Leong
Kam W
KW
Liao
Kin
K
D000199:Actins / Q000737:chemistry / Q000378:metabolism; D000328:Adult; D001854:Bone Marrow Cells / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D002460:Cell Line; D015638:Cytochalasin D / Q000378:metabolism; D003599:Cytoskeleton / Q000737:chemistry / Q000378:metabolism; D004548:Elasticity; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000737:chemistry* / Q000166:cytology* / Q000378:metabolism; D008962:Models, Theoretical; D019384:Nucleic Acid Synthesis Inhibitors / Q000378:metabolism; D013314:Stress, Mechanical; D013696:Temperature; D014783:Viscosity
D000199:Actins; D019384:Nucleic Acid Synthesis Inhibitors; D015638:Cytochalasin D