https://doi.org/10.1140/epjst/e2015-02453-4
Regular Article
Probing cytoskeleton dynamics by intracellular particle transport analysis
1 Fraunhofer Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg, Germany
2 Julius-Maximilians University Würzburg, Chemical Technology of Material Synthesis, Röntgenring 11, 97070 Würzburg, Germany
3 Max-Planck-Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
4 Humboldt University Berlin, Institute of Physics, Unter den Linden 6, 10099 Berlin, Germany
5 Bernstein Center for Computational Neuroscience Berlin, Philippstr. 13, Haus 2, 10115 Berlin, Germany
6 Leiden University, LION Leiden Institute of Physics, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
a e-mail: doris.heinrich@isc.fraunhofer.de
Received: 19 April 2015
Revised: 18 May 2015
Published online: 24 July 2015
All cellular functions arise from the transport of molecules through a heterogeneous, highly dynamic cell interior for intracellular signaling. Here, the impact of intracellular architecture and cytoskeleton dynamics on transport processes is revealed by high-resolution single particle tracking within living cells, in combination with time-resolved local mean squared displacement (I-MSD) analysis. We apply the I-MSD analysis to trajectories of 200 nm silica particles within living cells of Dictyostelium discoideum obtained by high resolution spinning disc confocal microscopy with a frame rate of 100 fps and imaging in one fixed focal plane. We investigate phases of motor-driven active transport and subdiffusion, normal diffusion, as well as superdiffusion with high spatial and temporal resolution. Active directed intracellular motion is attributed to microtubule associated molecular motor driven transport with average absolute velocities of 2.8 μm s−1 for 200 nm diameter particles. Diffusion processes of these particles within wild-type cells are found to exhibit diffusion constants ranging across two orders of magnitude from subdiffusive to superdiffusive behavior. This type of analysis might prove of ample importance for medical applications, like targeted drug treatment of cells by nano-sized carriers or innovative diagnostic assays.
© EDP Sciences, Springer-Verlag, 2015
