细胞外囊泡的表面修饰及其在中药活性成分递送中的应用

细胞外囊泡（Extracellular vesicles，EVs）是由细胞分泌的脂质囊泡，具有天然、稳定、生物相容性高等特点。近年来，EVs作为纳米仿生药物载体的报道逐渐增加，通过表面修饰技术获得功能化囊泡，进一步拓展了EVs的应用。中医药传承千年，疗效显著，但存在部分有效成分的水溶性差、生物利用度低、细胞毒性高等问题，利用EVs作为载体递送中药活性成分能够使药物的药效得到更好的发挥。该文介绍了EVs的种类、产生机制以及表面修饰方法，并总结了其作为中药活性成分载体的应用进展。 

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.