Volume 80, Number 4, November 2007
Article Number 48004
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 23 October 2007
EPL, 80 (2007) 48004
DOI: 10.1209/0295-5075/80/48004

Dynamics of fibers growing inside soft vesicles

D. Marenduzzo1 and E. Orlandini2

1  SUPA, School of Physics, University of Edinburgh - Mayfield Road, Edinburgh, EH9 3JZ, UK
2  Dipartimento di Fisica and Sezione INFN, Università di Padova - Via Marzolo 8, 35121 Padova, Italy

received 27 March 2007; accepted in final form 20 September 2007; published November 2007
published online 23 October 2007

We present 3D stochastic dynamic simulations of the growth of a semiflexible polymer inside a soft vesicle. We find that very stiff fibers stall soon and lock the membrane into a strongly deformed prolate shape. Fibers of intermediate stiffness buckle and form a toroidal configuration which distorts the membrane into an oblate shape. Finally, more flexible polymers form massive spool-like condensates with ordered domains, while the vesicle inflates isotropically. We discuss our results with respect to observations on cell shape in sickle red blood cells, developing erythrocytes, and genome packing inside bacteriophages. We quantify how the force felt by the fiber tip, and the vesicle aspect ratio, change during growth, and we discuss possible "synthetic biology" experiments to validate our results.

82.35.Lr - Physical properties of polymers.
36.20.Ey - Conformation (statistics and dynamics).
82.35.Pq - Biopolymers, biopolymerization.

© Europhysics Letters Association 2007