Controlling Circular RNA Encapsulation within Extracellular Vesicles for Gene Editing and Protein Replacement

Extracellular vesicles (EVs) are a population of vesicular bodies originating from cells, and EVs have been proven to have the potential to deliver different cargos, such as RNAs. However, conventional methods are not able to encapsulate long RNAs into EVs efficiently or may compromise the integrity of EVs. In this study, we have devised a strategy to encapsulate long circRNAs (>1000 nt) into EVs by harnessing the sorting mechanisms of cells. This strategy utilizes the inherent richness of circular RNAs in EVs and a genetic engineering method to increase the cytoplasmic concentration of target circRNAs, facilitating highly efficient RNA back-splicing to drive the circularization of RNAs. This allows target circRNAs to load into EVs with high efficiency. Furthermore, we demonstrate the practical applications of this strategy, showing that these circRNAs can be delivered by EVs to recipient cells for protein expression and to mice for gene editing.