Block Copolymer Templates for F actin Organization

Symmetric P(S-b-MMA) Short range spatial order achieved (70nm spacing). Geometric variation (5nm) is created with 5 min UV exposure.

Liquid Imaging of F actin In-situ AFM of extracellular F actin bundles and individual fibers. F actin height is 7nm. Double-helical architecture is resolved with pitch of 35-40nm.

PIs: R. J. Composto & Y. Goldman: NBIC Molecular Motors Subgroup

Motivation:

Use spatial and geometric signals to create an array of F actin which acts as tracts for molecular motors.

Goals:

1. Self-assemble block copolymers with short range periodicity commensurate with F actin size.
2. Develop AFM procedure to image fragile F actin.
3. Organize F actin on block copolymer templates.

Block Copolymer Systems:

1. oly(methyl-b-methacrylate)
2. poly(styrene-b-acrylic acid)

Alignment methods:

1. Thermal annealing
2. Solvent annealing
3. Grooved substrates

Results:

Organization of intracellular F actin in BAECs after 1 h.

F actin aligns along ridges of substrate (3mm x 3mm)

Conclusions:

• Intracellular F actin can be aligned by topography.
• Short range block copolymer (bcp) organization has been achieved
• Extracellular F actin has been imaged on substrates.
• Using the long range order of bcp’s to self-assemble extracellular F actin will lead to unprecedented control over molecular motors that convert chemical energy into mechanical energy.