Efficient RNA drug delivery using red blood cell extracellular vesicles

TLDR

Current programmable RNA therapies suffer from low uptake and high cytotoxicity, while extracellular vesicles offer a natural delivery mode but are limited by scarce, potentially unsafe cellular sources; human red blood cells, especially group O, provide a readily available, DNA‑free, universal donor source for large‑scale EV production. The study aims to develop a scalable method to produce RBC‑derived extracellular vesicles for delivering RNA therapeutics. The authors describe a strategy to generate large‑scale amounts of these EVs capable of carrying antisense oligonucleotides, Cas9 mRNA, and guide RNAs. RBCEVs achieved robust microRNA inhibition and efficient CRISPR‑Cas9 genome editing in human cells and xenograft mouse models, with no detectable cytotoxicity.

Abstract

Most of the current methods for programmable RNA drug therapies are unsuitable for the clinic due to low uptake efficiency and high cytotoxicity. Extracellular vesicles (EVs) could solve these problems because they represent a natural mode of intercellular communication. However, current cellular sources for EV production are limited in availability and safety in terms of horizontal gene transfer. One potentially ideal source could be human red blood cells (RBCs). Group O-RBCs can be used as universal donors for large-scale EV production since they are readily available in blood banks and they are devoid of DNA. Here, we describe and validate a new strategy to generate large-scale amounts of RBC-derived EVs for the delivery of RNA drugs, including antisense oligonucleotides, Cas9 mRNA, and guide RNAs. RNA drug delivery with RBCEVs shows highly robust microRNA inhibition and CRISPR-Cas9 genome editing in both human cells and xenograft mouse models, with no observable cytotoxicity.