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From drop to protocell : coacervates, vesicles and chirality
Living organisms have always been a source of inspiration for the design of molecular systems with interesting properties. Among the simplest biological models, protocells are assemblies of multiple compartments that enable complex exchanges in aqueous environments. Water-in-water emulsions offer a valuable synthetic platform for probing the principles of biomolecular organization in such systems.
Typically, all-aqueous phase separation occurs when two water-soluble components are mixed together, a process also known as coacervation. In particular, self-coacervation involves a single macromolecular species forming micrometer-sized liquid.
Recently, we have exploited ampholyte polymer chains to create highly stable micrometric droplets (Figure 1A). These droplets spontaneously sequester a wide range of species, from small molecules to macromolecules and colloids. (Figure 1B) Notably, the coacervates can adopt vesicle-like morphologies that define interfaces and compartmentalized domains, reminiscent of primitive cellular membranes (Figure 1C). These structures offer model systems for studying protocell behavior and constructing biomimetic microreactors.
Moreover, we demonstrate that these droplets can selectively sequester enantiomeric species, revealing an unexpected chiral discrimination in the partitioning behavior within the coacervate phase. Such chiral selectivity opens avenues for applications in asymmetric synthesis and chiral separation.