title: Quantifying cellular traction forces in three dimensions.
abstract: Cells engage in mechanical force exchange with their extracellular environment through tension generated by the cytoskeleton. A method combining laser scanning confocal microscopy (LSCM) and digital volume correlation (DVC) enables tracking and quantification of cell-mediated deformation of the extracellular matrix in all three spatial dimensions. Time-lapse confocal imaging of migrating 3T3 fibroblasts on fibronectin (FN)-modified polyacrylamide gels of varying thickness reveals significant in-plane (x, y) and normal (z) displacements, and illustrates the extent to which cells, even in nominally two-dimensional (2-D) environments, explore their surroundings in all three dimensions. The magnitudes of the measured displacements are independent of the elastic moduli of the gels. Analysis of the normal displacement profiles suggests that normal forces play important roles even in 2-D cell migration.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 210-41, Pasadena, CA 91125, USA.
authors.forename: Stacey A
authors.initials: SA
authors.lastname: Maskarinec
authors.forename: Christian
authors.initials: C
authors.lastname: Franck
authors.forename: David A
authors.initials: DA
authors.lastname: Tirrell
authors.forename: Guruswami
authors.initials: G
authors.lastname: Ravichandran
mesh_terms: D000180:Acrylic Resins; D000818:Animals; D057005:Bioengineering; D001696:Biomechanical Phenomena; D002465:Cell Movement / Q000502:physiology*; D003599:Cytoskeleton / Q000502:physiology; D004548:Elasticity; D005109:Extracellular Matrix / Q000502:physiology; D005353:Fibronectins / Q000502:physiology; D005456:Fluorescent Dyes; D021621:Imaging, Three-Dimensional; D051379:Mice; D018613:Microscopy, Confocal; D008863:Microspheres; D008954:Models, Biological; D041701:Swiss 3T3 Cells
chemical_list: D000180:Acrylic Resins; D005353:Fibronectins; D005456:Fluorescent Dyes; C016680:polyacrylamide gels