Stabilization of all-in-water emulsions to form capsules as artificial cells.

Building artificial cells using a bottom-up approach is a remarkable challenge that would be of interest for our understanding of the origin of life, the research of the minimal conditions required for life, the formation of bioreactors, but also for industrial applications. To date, capsules as liposomes, including polymersomes are widely used but the lack of membrane permeability and the difficulty to encapsulate biological materials within these structures hamper their use. By contrast, all in water emulsion droplets, including coacervate droplets are promising compartments mainly because they can spontaneously sequester chemicals. However they lack a membrane necessary to control the exchange between the inner and outer medium. Moreover, droplets tend to coalesce with time yielding macroscopic phase separation deleterious for any use as artificial cells. Recent advances, which we presently review, have shown that such droplets can be stabilized by using lipid membranes, liposomes, polymers, proteins but also particles, preventing coalescence. We finally discuss how different strategies could allow the future development of artificial cells from these stabilized all in water emulsion droplets