Open AccessA comparative study of living cell micromechanical properties by oscillatory optical tweezers
Author(s) -
Ming-Tzo Wei,
Angela Zaorski,
Huseyin C. Yalcin,
Jing Wang,
Samir N. Ghadiali,
Arthur Chiou,
H. Daniel Ou-Yang
Publication year - 2008
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.008594
Subject(s) - optical tweezers , viscoelasticity , materials science , oscillation (cell signaling) , biophysics , optics , cytoskeleton , optical force , optical power , nanotechnology , physics , chemistry , cell , composite material , biology , laser , biochemistry
Micromechanical properties of biological cells are crucial for cells functions. Despite extensive study by a variety of approaches, an understanding of the subject remains elusive. We conducted a comparative study of the micromechanical properties of cultured alveolar epithelial cells with an oscillatory optical tweezer-based cytorheometer. In this study, the frequency-dependent viscoelasticity of these cells was measured by optical trapping and forced oscillation of either a submicron endogenous intracellular organelle (intra-cellular) or a 1.5microm silica bead attached to the cytoskeleton through trans-membrane integrin receptors (extra-cellular). Both the storage modulus and the magnitude of the complex shear modulus followed weak power-law dependence with frequency. These data are comparable to data obtained by other measurement techniques. The exponents of power-law dependence of the data from the intra- and extra- cellular measurements are similar; however, the differences in the magnitudes of the moduli from the two measurements are statistically significant.