Peptide display on small extracellular vesicles directs tissue-specific tropism and delivery of gene editing machinery

Small extracellular vesicles (EVs) deliver nucleic acid and protein therapeutics that promote tissue repair, however, there are few approaches to direct the tropism of EVs to specific tissues. Here, we address this challenge by engineering EVs to display a peptide library on the surface of EVs that is linked to barcoded guide RNA payloads (gRNAs). We show how these EVs can be administered systemically into mouse models and the cellular uptake of these gRNA-bearing EVs assessed by recovery of the small RNAs followed by PCR amplification and barcode sequencing. Since the design of the peptide library was linked to specific barcodes encoded on the same plasmid, subsequent sequencing of barcode sequences recovered from tissues revealed profiles of EV uptake associated with the display of specific peptide sequences on the surface of EVs. Therefore, candidate peptide motifs were cloned for validation using in vivo and in vitro readouts. In addition to the barcode-based tissue profiling, gRNA-laded EVs mediated functional gene editing in the Cre-loxP R26 LSL-tdTomato reporter mouse model in vivo. These studies demonstrated how EV display linked with barcoded gRNA payloads can address barriers to EV-based delivery of gene editing therapies.