Extracellular vesicle-based delivery systems for nucleic acid therapeutics

Nucleic acid-based therapeutics, which involve the manipulation of genetic materials to treat or prevent diseases, have gained considerable attention, leading to the approval of medicines such as COVID-19 vaccines, patisiran (Onpattro), and nusinersen (Spinraza). However, their clinical application is hindered by challenges such as nuclease degradation, poor biodistribution, limited cellular uptake, and inefficient endosomal escape. Extracellular vesicles (EVs), which are natural nanoscale drug delivery systems derived from various eukaryotic and prokaryotic cells, offer a safe, efficient, specifically targeted, and non-pathogenic method for nucleic acid delivery. In this review, we summarize the classical methods and the latest research advances in EV preparation and nucleic acid loading. Additionally, we review the primary administration routes for nucleic acid-loaded EVs, such as intravenous, local, oral, intranasal, and inhalation delivery. By addressing these aspects, this review aims to guide the optimal design and clinical application of nucleic acid-loaded EVs.