Systemic chemotherapy is a conventional and important strategy for inhibition of cancer progression, but it is usually accompanied by various adverse effects. Targeting drug delivery systems, effective tools to avoid the adverse effects of chemotherapy, have been intensively studied and developed. Recently, the emerging application of exosomes and exosome-mimics (small extracellular vesicles [sEVs]) in targeted drug delivery and therapeutics has been widely appreciated. The sEVs-based delivery system comprises three basic components: vesicles, cargoes and surface decorations. In this article, we review the current status, existing challenges and future directions in this field from the following aspects: selection and production of vesicles; cargoes and methods to load them into vesicles; modifications to the surfaces of vesicles; as well as ways to prolong the half-life of sEVs in the circulation. Existing and emerging data indicate that sEVs are promising nanocarriers for clinical use, but additional efforts are needed to translate research findings into therapeutic products.

中文翻译：

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癌症治疗中的小细胞外囊泡加载系统：现状和前进方向

全身化疗是抑制癌症进展的常规且重要的策略，但通常伴随着各种不良反应。靶向给药系统是避免化疗不良反应的有效工具，已经得到深入研究和开发。最近，外泌体和外泌体模拟物（小细胞外囊泡 [sEVs]）在靶向药物递送和治疗中的新兴应用已得到广泛认可。基于 sEV 的传递系统包括三个基本组成部分：囊泡、货物和表面装饰。在本文中，我们从以下几个方面回顾了该领域的现状、存在的挑战和未来的方向：囊泡的选择和生产；货物和将它们装入囊泡的方法；对囊泡表面的修饰；以及延长循环中 sEV 半衰期的方法。现有和新出现的数据表明，sEV 是用于临床的有前途的纳米载体，但需要额外的努力将研究结果转化为治疗产品。