Phase separation and gelation of chemically reactive macromolecules.

Abstract

Phase transitions are ubiquitous in inanimate systems, and recent discoveries have shown that they also play a key role in living cells. Many membrane-less, liquid-like organelles (“biomolecular condensates”) have been shown to form via liquid-liquid phase separation (LLPS). Intriguingly, several such condensates display irreversible aging behavior akin to gelation. In this work, we first construct a theoretical framework to investigate the phase behavior of multi-component macromolecular systems in which chemical reactions, phase separation and gelation are present concurrently. We then formulate a thermodynamically consistent phase-field model to study coupled compositional and structural phase transformation phenomena in chemically reactive, multi-component biomolecular systems undergoing LLPS. The mesoscale nature of phase-field models enables the study of spatially extended systems over macroscopic timescales. Results such as phase diagrams that capture LLPS and gelation, size distribution of droplets and morphology of gel-state condensates will be presented.