The present invention pertains to an inventive release mechanism for extracellular vesicle (EV)-mediated intracellular and intramembrane delivery of therapeutic polypeptides. More specifically, the invention relates to EVs comprising polypeptide constructs which comprise a therapeutic polypeptide releasably attached to an exosomal polypeptide. Furthermore, the present invention pertains to manufacturing methods, pharmaceutical compositions, medical uses and applications, and various other embodiments related to the inventive EVs.