Self-Assembled Charged Hydrogels Control the Alignment of Filamentous Actin

We demonstrate a novel route to control attachment of filamentous actin (F-actin) on hydrogel films. By incorporating an amine-terminated silane, the hydrogel surface charge and surface topography are varied. With increasing silane content, F-actin reorients from perpendicular to parallel to the hydrogel surface, ceases to wobble, and forms mainly elongated or cyclic structures. F-Actin coverage reaches a maximum at 2.5 vol% silane and declines at higher silane content. This biphasic behavior is explained by the simultaneous increase in surface charge and the self-assembly of a micron scale pattern of positively charged islands. Our approach provides guidelines for constructing nanoscale tracks to guide motor proteins underlying nano-engineered devices such as molecular shuttles. Disciplines Engineering | Materials Science and Engineering Comments Suggested Citation: Park, J.H., Y. Sun, Y.E. Goldman and R.J. Composto. (2010). "Self-assembled charged hydrogels control the alignment of filamentous actin." Soft Matter. Vol. 6:5. pp. 915-921 © 2010 Royal Society of Chemistry http://dx.doi.org/10.1039/B918304C This journal article is available at ScholarlyCommons: http://repository.upenn.edu/mse_papers/184 Self-assembled charged hydrogels control the alignment of filamentous actin† Jung Hyun Park, Yujie Sun, Yale E. Goldman and Russell J. Composto* Received 4th September 2009, Accepted 30th November 2009 First published as an Advance Article on the web 21st December 2009 DOI: 10.1039/b918304c We demonstrate a novel route to control attachment of filamentous actin (F-actin) on hydrogel films. By incorporating an amine-terminated silane, the hydrogel surface charge and surface topography are varied. With increasing silane content, F-actin reorients from perpendicular to parallel to the hydrogel surface, ceases to wobble, and forms mainly elongated or cyclic structures. F-Actin coverage reaches a maximum at 2.5 vol% silane and declines at higher silane content. This biphasic behavior is explained by the simultaneous increase in surface charge and the self-assembly of a micron scale pattern of positively charged islands. Our approach provides guidelines for constructing nanoscale tracks to guide motor proteins underlying nano-engineered devices such as molecular shuttles.