(657i) Enhanced Polymer Transport in a Crowdier Nanoslit Micropost Array

We
found enhanced transport of DNA molecules in more crowded nanoslit micropost
arrays, contrary to the expectation of slower diffusion in more crowded
environments. The nanofabricated post arrays are weakly attractive and emulate
crowded interactive environments, resulting in weak DNA adsorption. The
coupling between DNA diffusion with adsorption to the microposts results in
increased mobility with increasing post density, in contrast to studies of
decreased DNA/protein mobility in dense gels. Hidden Markov analysis was
employed to identify the apparent free energy barriers, which is in agreement
with theoretical estimates of based on polymer conformation fluctuations
between posts. We also performed Langevin dynamics simulations of
macromolecular transport in micropost arrays to verify the enhanced diffusion
in denser arrays. Faster DNA diffusion and hopping in crowded systems have
important implications for biological systems and for technological
applications such as macromolecule purification, and targeted drug delivery.