Spatiotemporal Control of Formation of Dynamic Protein Fibre Networks via Photophysical Effects of a Focused Laser Beam

Spatiotemporal control of the formation of dynamic microtubule networks via photophysical effects is demonstrated. Focused irradiation with a continuous laser beam at an air/solution interface can accumulate tubulin proteins at/around the laser focus, which leads to the formation of highly aligned microtubule networks. The laser-fabricated microtubule networks can exhibit various dynamic behaviours such as translational motion, bundling, and cilia-like beating in the presence of motor protein and chemical energy, ensuring biological activities of the laser-fabricated microtubule networks. The accumulation of proteins with a focused laser beam is attributed to the local increases in concentration and temperature produced through two photophysical effects, i.e., laser trapping by optical forces and heat generation by photoabsorption, which allow the fabrication of complex microtubule networks without specific photochemical reactions (e.g., the use of photochemically active crosslinkers). We anticipate that this laser method will provide fundamental insights into the structure-motion relationship of biomolecular assemblies (e.g., cytoskeletal networks) and expand the bioengineering of protein-based actuators for macrorobotic systems.