[Construction of engineered exosomes with high loading efficiency of cellular endogenous proteins]

Exosomes have many advantages as natural drug delivery carriers, but their application is limited by the inefficient loading of intracellular drugs (such as proteins and nucleic acids). In this study, mCherry, a red fluorescent protein, was used as the endogenous cargo target. Through gene modification of donor cells and fusion expression of membrane localization elements (PB, CAAX, Palm and CD63), mCherry was specifically sorted into exosomes through biogenesis. Results show that CD63 had the highest sorting efficiency, followed by Palm. PB and CAAX led enrichment of mCherry on the plasma membrane, but not in exosomes. The approach provides an alternative to facilitate packaging of cargo by exosomes and thus to increase the efficient delivery of endogenous protein drugs.