Exosomes are natural carriers of signaling molecules including miRNA.
Membrane proteins including tetraspanins are selectively enriched on membrane of exosomes.
Homing peptides targeting unknown receptors in vivo can be displayed on the surface of exosomes.
Surface display of homing peptides can be easily achieved by fusion with tetraspanins using overlapping PCR.
Engineered exosomes can be loaded with therapeutic miRNAs to realize targeted delivery in vivo.