Micropatterning of myosin on O-acryloyl acetophenone oxime (AAPO), layered with bovine serum albumin (BSA)

Abstract

This paper describes a simple laser-based method for preparing microchannels in a bilayer system consisting of a UV sensitive polymer, O-acryloyl acetophenone oxime (AAPO), layered with a protein-blocking agent, bovine serum albumin (BSA). Patterned surfaces suitable for biomolecular attachment are achieved through the use of a computer-controled laser ablation system, comprising a research-grade inverted optical microscope, a pulsed nitrogen laser emitting at 337 nm and a programmable X-Y-Z stage. Exposed areas with diameters of 5–20 μm, 1–5 μm, and sub-micron widths are readily achieved by focussing through a 20×dry objective, a 40×dry objective, or a 100×oil immersion lens, respectively. When combined with a sub-micron resolution, high-speed, computer-controlled X-Y-Z stage, well-defined channels or arrays can be patterned in the AAPO, revealing either the underlying hydrophobic primed-glass surface, or pendant amino groups suitable for the covalent binding of biomolecules, depending on the amount of energy delivered to the surface. The subsequent removal of the attached BSA creates well-defined regions with high contrast. Myosin was physically adsorbed to the base of the channels, and fluorescently-labeled actin microfilaments were observed to selectively bind to the myosin following ATP hydrolysis, confirming retention of bioactivity.