Development of a Nanoscale DNA Based Force Transducer

Michael W. Hudoba, Carlos E. Castro Introduction Biological cells navigate their environment by exerting a field of traction forces applied via a multitude of localized attachment points to the surrounding extracellular matrix termed focal adhesion sites. During cellular migration, the cell cytoskeleton protrudes forward in the direction of motion, adheres to the extracellular matrix, and then applies contractile forces at these adhesion sites to pull the body of the cell forward (figure 1). Different cells have been shown to exhibit different traction force fields during migration, and understanding these cellular traction forces (CTF) at the molecular scale can allow scientists to engineer systems to manipulate cell migration, for example for cell separation. This research aims to improve upon existing methods of traction force measurement by developing a nanoscale molecular force transducer (NMFT) using a process known as DNA origami. Scaffolded DNA origami is a process of folding single stranded DNA (ssDNA) into 2 and 3 dimensional shapes via molecular self-assembly. The NMFTs will improve upon current CTF measurements by improving resolution (piconewton force resolution with nanometer spatial resolution), and by enabling measurement of single molecule force interactions in a physiologically realistic 3 dimensional environment.