The anionic ring-opening polymn. of episulfides has been successfully applied in emulsion. The polymn. proceeded with a living mechanism but was characterized by a limiting conversion, presumably arising from the increase in viscosity in the polymer. To the knowledge of the authors, only two other cases of living anionic polymn. in emulsion are known (silicones and cyanoacrylates); the addnl. novelty presented by episulfides is the ease of end-functionalization. Furthermore, the emulsion polymn. allowed the prepn. of highly stable particles, which, due to their PEGylated surface and their appropriate diam., can be applied in the biomedical field as nanocarriers. [on SciFinder (R)]