It is also possible to use latex particles for Ramsden stabilization and then fuse these particles to form a permeable shell or capsule, called a colloidosome. Moreover, Ramsden emulsion droplets are also suitable templates for micro-encapsulation and the formation of closed, non-permeable capsules. This form of encapsulation can also be applied to water-in-water emulsions (dispersions of phase-separated aqueous polymer solutions), and can also be reversible. Pickering-stabilized microbubbles may have applications as ultrasound contrast agents.