Sustained, reversible and adaptive non-equilibrium steady states of a dissipative DNA-based system

Inspired by nature, researchers have developed several chemical fuel-driven supramolecular systems aimed at achieving improved kinetic control over their formation and functions. Alongside, DNA-based systems regulated by energy-dissipating mechanisms have been reported. However, these systems typically rely on batch additions of chemical fuels to closed reactors, generating transient non-equilibrium states, which contrast the sustained and highly adaptable non-equilibrium steady states (NESS) achieved by living systems through continuous energy dissipation. Here, we demonstrate sustained NESS of a dissipative DNA strand-displacement reaction achieved through the continuous supply of an RNA fuel to a stirred semi-batch reactor, using a custom automated setup that enables tuneable fuel infusion rates and in situ fluorescence monitoring. Similar to biological NESS, our system dynamically adapts (in real-time) to subtle variations in fuel supply, approaching different steady-state levels of the strand-displacement reaction on-the-fly. Using a kinetic model of the reaction network, we confirm that the obtained NESS correspond to actual non-equilibrium compositions of the system.