Affiliations: Physics of Complex Fluids, Department of Science & Technology, MESA+ Institute of Nanotechnology, University of Twente, Enschede, The Netherlands
Note: [] Address for correspondence: Yixuan Li, Physics of Complex Fluids, Department of Science & Technology, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands. Tel.: +31 53 489 3097; Fax: +31 53 489 1096; E-mail: Y.Li@tnw.utwente.nl.
Abstract: We studied the dynamics of ballistically injected latex particles (BIP) inside endothelial cells, using video particle tracking to measure the mean squared displacement (MSD) as a function of lag time. The MSD shows a plateau at short times and a linear behavior at longer times, indicating that the BIP are trapped into a viscoelastic network. To reveal more about the molecular constituents and the dynamics of this actin network, we added a variety of drugs. Latrunculin and Jasplakinolide aimed at intervening with the actin network caused a strong increase in MSD, whereas Taxol aimed at microtubules gave no measurable change in MSD. Additional corroborating information about these drug effects were obtained from MSD amplitude and exponent distributions and from fluorescent staining images of the actin and microtubule networks. Our evidence strongly suggests that BIP are primarily embedded in the actin network. Additional drug interventions aimed at disabling non-thermal forces could not conclusively resolve the nature of the forces driving BIP dynamics.
