Self-Assembled Charged Hydrogels Control the
Alignment of Filamentous Actin.
Soft Matter, In Press, 2010.
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.