Tuning interfacial fluidity and colloidal stability of membranized coacervate protocells.

The cell membrane not only serves as the boundary between the cell's interior and the external environment but also plays a crucial role in regulating fundamental cellular behaviours. Interfacial membranization of membraneless coacervates, formed through liquid-liquid phase separation (LLPS), represents a reliable approach to constructing hierarchical cell-like entities known as protocells. In this study, we demonstrate the capability to modulate the interfacial membrane fluidity and thickness of dextran-bound coacervate protocells by adjusting the molecular weight of dextran or utilizing dextranase-catalyzed hydrolysis. This modulation allows for rational control over colloidal stability, interfacial molecular transport and cell-protocell interactions. Our work opens a new avenue for surface engineering of coacervate protocells, enabling the establishment of cell-mimicking structures and behaviours.