title: Nonequilibrium fluctuations of mechanically stretched single red blood cells detected by optical tweezers.
abstract: We study the thermal and out-of-equilibrium mechanical dynamics of single, living human red blood cells (RBCs) by combining two-probe passive and active microrheology techniques. Both experiments were performed quasisimultaneously on the same cell using two identical polystyrene probes, biochemically attached to the cell membrane. We obtained compelling evidence of nonequilibrium fluctuations in the RBCs under physiological condition and without the influence of any external chemicals. The spectral distributions of metabolically driven forces and viscoelastic response were evaluated in the relaxed and stretched states, intended to simulate the varying natural environment of the cells during blood circulation. We found that the internally generated forces are more pronounced in the stretched state, suggesting a stress-dependent RBC activity.
authors.affiliation: ICFO-The Institute of Photonic Sciences, Av. Carl Friedrich Gauss, 3, Castelldefels, 08860 Barcelona, Spain. michal.wojdyla@icfo.es
authors.forename: Michal
authors.initials: M
authors.lastname: Wojdyla
authors.forename: Saurabh
authors.initials: S
authors.lastname: Raj
authors.forename: Dmitri
authors.initials: D
authors.lastname: Petrov
mesh_terms: D001696:Biomechanical Phenomena; D002462:Cell Membrane; D004548:Elasticity; D004912:Erythrocytes; D006801:Humans; D055595:Mechanical Phenomena; D052898:Optical Tweezers; D012212:Rheology / Q000379:methods*; D014783:Viscosity