Extracellular vesicles for targeted drug delivery: advances in surface modification strategies and therapeutic applications.

Extracellular vesicles (EVs) refer to a heterogeneous group of cell-derived membrane structures originating from endosomes or plasma membranes. EVs can be used as excellent medication carriers due to their characteristic as natural carriers for bioactive substances. They can be employed for intercellular communication to transport bioactive lipids, proteins, RNAs, DNA, and peptide segments for releasing into the extracellular surroundings. This paper discusses the biological characteristics of EVs, current methodologies for their isolation and purification, with particular emphasis on emerging strategies for EVs surface engineering. The methods for surface modification can be categorized into two approaches: pre-isolation and post-isolation. Pre-isolation methods involve genetic manipulation or metabolic engineering of the source cells to alter the EVs surface, while post-isolation methods entail physical or chemical modifications after EVs have been isolated. Based on the modification methods mentioned above, we present how these modified EVs can be utilized to treat specific diseases, including brain disorders, tumors, and liver conditions.