Assessment of mechanical properties of adherent living cells by bead micromanipulation: comparison of magnetic twisting cytometry vs optical tweezers.
We compare the measurements of viscoelastic properties of adherent alveolar epithelial cells by two micromanipulation techniques: (i) magnetic twisting cytometry and (ii) optical tweezers, using microbeads of same size and similarly attached to F-actin. The values of equivalent Young modulus E, derived from linear viscoelasticity theory, become consistent when the degree of bead immersion in the cell is taken into account. E-values are smaller in (i) than in (ii): approximately 34-58 Pa vs approximately 29-258 Pa, probably because higher stress in (i) reinforces nonlinearity and cellular plasticity. Otherwise, similar relaxation time constants, around 2 s, suggest similar dissipative mechanisms.
Laurent
Valérie M
VM
INSERM Unité 492, Physiopathologie et Thérapeutique Respiratoires, Faculté de Médecine, Université Paris XII, Créteil, France. v.laurent@creitel.inserm.fr
Hénon
Sylvie
S
Planus
Emmanuelle
E
Fodil
Redouane
R
Balland
Martial
M
Isabey
Daniel
D
Gallet
François
F
D002448:Cell Adhesion / Q000502:physiology; D004548:Elasticity; D005434:Flow Cytometry / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D008280:Magnetics / Q000295:instrumentation; D008863:Microspheres; D055095:Optics and Photonics / Q000295:instrumentation*; D011650:Pulmonary Alveoli / Q000502:physiology; D015203:Reproducibility of Results; D020545:Respiratory Mucosa / Q000502:physiology*; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D014783:Viscosity