Self-organized Gels in DNA/F-Actin mixtures without Crosslinkers

ORAL

Abstract

Interactions between flexible chains and rigid rods govern a broad range of soft matter systems. As a model system of like-charged rigid rods and flexible chains, we examine mixtures of DNA and filamentous actin (F-actin). Confocal microscopy reveals the formation of elongated nematic F-actin domains reticulated via defect-free vertices into a network embedded in a mesh of random DNA. Synchrotron small-angle x-ray scattering (SAXS) indicates that the DNA mesh squeezes the F-actin domains into a nematic state with an inter-actin spacing that decreases with increasing DNA concentration. Salt strongly influences the domain sizes and transitions the system from a counterion-controlled regime to a depletion-controlled regime, both mechanisms of which are entropic in origin.

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Authors

  • John Butler

    • University of Illinois at Urbana-Champaign

  • G.H. Lai

    • University of Illinois at Urbana-Champaign
    • Dept of Physics

  • Olena Zribi

    • University of Illinois at Urbana-Champaign

  • Ivan Smalyukh

    • University of Colorado at Boulder

  • Thomas Angelini

    • Havard University
    • SEAS, Harvard

  • Kirstin Purdy

    • University of Illinois at Urbana-Champaign

  • Ramin Golestanian

    • University of Sheffield

  • G.C.L. Wong

    • University of Illinois at Urbana-Champaign
    • Depts of Mat. Science Eng. and Physics, and Seitz Materials Research Lab, U of Illinois, Urbana-Champaign
    • Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign