Alternating Binary Droplets-based Protocell Networks Driven by Heterogeneous Liquid-liquid Phase Separation.

As the emergence of prototissues promotes the evolutionary transformations of protolife, tissue-like networks derived from cytomimetic systems have been studied by using artificial cells as building blocks to mimic prototissues at a higher-organizational level. However, liquid-like networks originating from liquid-liquid phase separation (LLPS), especially heterogeneous LLPS, are less reported. Herein we report a binary liquid droplet-based protocell network composed of coacervates and aqueous two-phase systems (ATPS) droplets arranged in an alternating sequence, integrating both associative and segregative LLPS. This network with worm-like chains can be specifically achieved only when the attached droplets are partially engulfed, mediated by the interfacial tension between coacervate and ATPS droplets. Notably, the interconnected droplets within the network are capable of spatially self-sorting of biomacromolecules into separate domains, thereby facilitating biomacromolecular extraction and biological reactions within designated droplets. Upon changes in the external environment, the network can be reconfigured to enable morphological regulation of tri-enzymatic cascade reactions. Overall, this work highlights that an all-aqueous network, coupling of associative and segregative LLPS, can be engineered as a possible route towards a hybrid prototissue-like system, offering new insights into the design of higher-order biomimetic systems utilizing liquid soft matter.