Spatial Shifting of Biocondensate Assembly Zone in a Microfluidic Gradient of Dissipative Condition

Pursuing non-equilibrium chemistry with (bio)molecules is of utmost importance for the design of life-like dynamic materials that emerge in a constant flux of energy. Herein, we explore spatial localization of dissipative self-assembly of biocondensate (DNA-histone) via passing chemical fuel (histone) and one fuel-degrading agent (trypsin) through two arms of the Y-shaped microfluidic chip. In this case, a continuous supply of fuel and fuel-degrading agent results self-assembly of biocondensate, maintaining a non-equilibrium steady state (NESS). We find in the presence of gradient of dissipating conditions, the formation zone of biocondensate drifts towards fuel-rich zone (away from dissipating zone). In absence of fuel-degrading agent, diffusive transport of free DNA towards histone channel (perpendicular to advection) is restricted as it formed much larger micron-sized biocondensate at the center of the channel (the meeting point of two flows). However, this sidewise DNA diffusion is operative in the presence of fuel-degrading agent and therefore, the formation zone shifted to histone-rich zone. Furthermore, we demonstrate that in the presence of trypsin, catalytic DNA's peroxidase reactivity can be moved to histone-rich region. Transposition of self-assembly process in a gradient of dissipative conditions will be of importance in the development of spatially-controlled chemistry, reaction-diffusion processes.