Interfacial Liquid-Liquid Phase Separation-Driven Polymerization-Induced Electrostatic Self-Assembly

Development of spatially restricted liquid-liquid phase separation (LLPS) systems emulating biomolecular condensates is a major challenge in coacervating materials science, due to lack of approaches for spatially restricted coacervation of sequence-defined zwitterionic segments resembling intrinsically disordered proteins. Herein, we present interfacial LLPS-driven polymerization-induced electrostatic self-assembly, namely, interfacial LLPS-PIESA. The asymmetric charge sequence patterning of zwitterionic growing segments is achieved via spontaneous polymerization of ion-pair monomers within a nanopartide core-shell interface. We show that charge sequence can profoundly affect the self-coacervation, leading to droplet dispersions, dense coacervates, and free-standing hydrogels. Moreover, the interfacial LLPS-PIESA shows a programmed hierarchical condensation self-assembly mechanism involving vesicles-to-lamellae transition, interfacial self-coacervation, lamellae-to-sheets transition, layer-by-layer sheet self-assembly, spatially restricted condensation and agglomeration, and redispersing into fibril network condensates under dynamic evolving surface charge regulation. The spatially restricted asymmetric charge sequence patterning, interfacial self-coacervation, and programmed hierarchical condensation self-assembly, all these elements can serve as the primary principles for the asymmetric charge sequence patterning design of hierarchically nanostructured condensates that emulate cellular biomolecular condensates.

Automated summary

The study introduces a new method called interfacial LLPS-PIESA, which achieves asymmetric charge sequence patterning of zwitterionic growing segments through spontaneous polymerization of ion-pair monomers within a nanoparticle core-shell interface. The research demonstrates that the charge sequence can profoundly impact self-coacervation, leading to different forms of coacervates. Additionally, the study reveals a programmed hierarchical condensation self-assembly mechanism.