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Viscoelastic behaviour of human mesenchymal stem cells.

Tan SC, Pan WX, Ma G, Cai N, Leong KW, Liao K - BMC Cell Biol. (2008)

Bottom Line: 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.Its viscoelstic behaviour are dependent on the structural integrity of the F-actin filaments and temperature.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457, Singapore. tanc0101@ntu.edu.sg

ABSTRACT

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.

Conclusion: hMSCs behave as viscoelastic solid. Its viscoelstic behaviour are dependent on the structural integrity of the F-actin filaments and temperature.

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Related in: MedlinePlus

Micropipette aspiration of hMSCs treated with the highest concentration (20 μM) of cytochalasin D (A – D). Images are displayed at T = 1 s, 15 s, 100 s and 200 s after the application of step aspiration pressure, respectively. The aspiration length of the cell increased significantly due to the disruption of F-actin filaments.
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Figure 5: Micropipette aspiration of hMSCs treated with the highest concentration (20 μM) of cytochalasin D (A – D). Images are displayed at T = 1 s, 15 s, 100 s and 200 s after the application of step aspiration pressure, respectively. The aspiration length of the cell increased significantly due to the disruption of F-actin filaments.

Mentions: The F-actin network of hMSCs was disrupted to certain degree after treatment with cytochalasin D at 20°C (Fig. 5). Under such condition, the hMSCs no longer displayed the typical viscoelastic behaviour of solid materials. The cells experienced a much slower rate of increase in aspiration length with no obvious initial jump, and tended towards a much higher equilibrium length compared to cells tested under the control condition (Fig. 2). The addition of cytochalasin D at various concentrations caused E0 and E∞ to decrease significantly by 67% to 84% from the control (p < 0.001) (Fig. 3). There was no significant change in E0 and E∞ when the concentration was increased from 0.2 μM to 2.0 μM, the IC50 value for hMSC (p > 0.1). The apparent viscosity, μ, increased significantly from the control condition and low concentration of cytochalasin D (0.2 μM) by up to 255% as the concentration was increased to 2.0 μM and 20 μM (p < 0.05) (Fig. 4).


Viscoelastic behaviour of human mesenchymal stem cells.

Tan SC, Pan WX, Ma G, Cai N, Leong KW, Liao K - BMC Cell Biol. (2008)

Micropipette aspiration of hMSCs treated with the highest concentration (20 μM) of cytochalasin D (A – D). Images are displayed at T = 1 s, 15 s, 100 s and 200 s after the application of step aspiration pressure, respectively. The aspiration length of the cell increased significantly due to the disruption of F-actin filaments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2500016&req=5

Figure 5: Micropipette aspiration of hMSCs treated with the highest concentration (20 μM) of cytochalasin D (A – D). Images are displayed at T = 1 s, 15 s, 100 s and 200 s after the application of step aspiration pressure, respectively. The aspiration length of the cell increased significantly due to the disruption of F-actin filaments.
Mentions: The F-actin network of hMSCs was disrupted to certain degree after treatment with cytochalasin D at 20°C (Fig. 5). Under such condition, the hMSCs no longer displayed the typical viscoelastic behaviour of solid materials. The cells experienced a much slower rate of increase in aspiration length with no obvious initial jump, and tended towards a much higher equilibrium length compared to cells tested under the control condition (Fig. 2). The addition of cytochalasin D at various concentrations caused E0 and E∞ to decrease significantly by 67% to 84% from the control (p < 0.001) (Fig. 3). There was no significant change in E0 and E∞ when the concentration was increased from 0.2 μM to 2.0 μM, the IC50 value for hMSC (p > 0.1). The apparent viscosity, μ, increased significantly from the control condition and low concentration of cytochalasin D (0.2 μM) by up to 255% as the concentration was increased to 2.0 μM and 20 μM (p < 0.05) (Fig. 4).

Bottom Line: 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.Its viscoelstic behaviour are dependent on the structural integrity of the F-actin filaments and temperature.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457, Singapore. tanc0101@ntu.edu.sg

ABSTRACT

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.

Conclusion: hMSCs behave as viscoelastic solid. Its viscoelstic behaviour are dependent on the structural integrity of the F-actin filaments and temperature.

Show MeSH
Related in: MedlinePlus