Fig. 1

Ternary phase diagram of mixed polymer solution （a） （reprinted from Ref. [6]）; Phase diagram of gelatin / maltodextrin mixture （b） （reprinted from Ref. [7]）"

Fig. 2

Schematic diagram of preparation of water-in-water emulsions by capillary microfluidic device （a） （reprinted from Ref. [11]）; （b） （reprinted from Ref. [12]）"

Fig. 3

Confocal optical micrographs showing the microstructure evolution of water-in-water droplets （a） （reprinted from Ref. [16]）; water-in-water droplets produce different morphologies with the change of shear rate （b） （reprinted from Ref. [17]）"

Fig. 4

Polymer fraction of gelatin （a）; relative total polymer concentration calculated in the phase boundary zone for the chemical system （b） （reprinted from Ref. [24]）"

Fig. 5

Schematic diagram of protein stabilized water-in-water emulsion （a） （reprinted from Ref. [31]）; schematic diagram of triblock copolymer stabilized water-in-water emulsion （b） （reprinted from Ref. [30]）; schematic diagram of water-in-water emulsions stabilized by gel method （c） （reprinted from Ref. [32]）"

Fig. 6

Illustration of RNA- and DNA-loaded water-in-water emulsions （a） （reprinted from Ref. [43]）; Proof-of-concept image of single cell encapsulation （b） （reprinted from Ref. [12]）"