Technologies for EV Surface Modification and its Application in Targeted Therapy

In the new era of precision medicine, a personalized drug delivery system with better biocompatibility and higher drug loading efficiency needs to be established to overcome a series of obstacles in drug delivery to target tissues. As natural nanoscale biological vesicles, extracellular vesicles (EVs) are attractive novel drug carriers due to their inherent low immunogenicity, long circulation time, and an enhanced capacity to cross biological barriers. However, efficient and targetable drug delivery is still the bottleneck for further application of EVs. To solve this problem, various surface modification technologies for EVs have emerged in recent years and can be divided into two main categories: genetic manipulation and direct surface modification. Through design and manipulation, functionalized EVs exhibit more specific biological distributions and enhanced pharmacokinetics, which improve the application potential of EVs in drug loading. In this chapter, we summarize the specific methods of EV surface modification and typical schemes for using functionalized EVs for targeted therapy and discuss the advantages, current limitations, and future development directions of EVs as carriers for targeted drug delivery.