Based on this, we hypothesized that dispersing hydrophilic polymers in oil and pouring this mixture in water should induce formation of an aqueous droplet within the oil droplet upon water diffusion to equilibrate osmotic pressure. Here, we demonstrate that this feature indeed occurs using several oils (octanol, tributyrin or oleic acid…) containing various hydrophilic polymers (PEG, bPEI or PVPone), which were successfully solubilized within.