Surface Modification Strategies of Extracellular Vesicles and Their Applications in Natural Products Delivery

Extracellular vesicles (EVs) are small membrane vesicles secreted from cells， possessing advantages of nature， high stability and favorable biocompatibility. Recently， EVs have been widely employed as biomimetic nano carriers in drug delivery， and surface modification extends their application. Chinese herbal medicines have been used for disease treatment over thousands of years， however， poor solubility， low bioavailability and high cytotoxicity of some of active ingredients limits their therapeutic effects. Therefore， using EVs as carriers of active ingredients in Chinese medicines for drug delivery is an efficient approach to enhance their bioavailability as well as the corresponding therapeutic efficiency. In this review， we summarize different types of EVs and their respective production process， present the surface modification methods to obtain functional EVs， and introduce some of their applications in natural products delivery.