文献：Embryonic Stem Cells-Derived Exosomes Endowed with Targeting Properties as Chemotherapeutics Delivery Vehicles for Glioblastoma Therapy

文献链接：https://xueshu.baidu.com/usercenter/paper/show?paperid=cb709a7ab8e9444aa2b2268c3fd020c4&site=xueshu_se

作者：Qingwei Zhu, Xiaozheng Ling, Yunlong Yang, Juntao Zhang, Qing Li, Xin Niu, Guowen Hu, Bi Chen, Haiyan Li, Yang Wang,and Zhifeng Deng

相关产品：DSPE-PEG2000-cRGDyK 磷脂-聚乙二醇2000-cRGDyK肽

原文摘要：Exosomes are nanosized membrane vesicles (30–100 nm) that can easily penetrate the blood–brain barrier, safely deliver therapeutic drugs, and be modified with target ligands. Embryonic stem cells (ESCs) provide abundant exosome sources for clinical application due to their almost unlimited self-renewal. Previous studies show that exosomes secreted by ESCs (ESC-exos) have antitumor properties. However, it is not known whether ESC-exos inhibit

glioblastoma (GBM) growth. In this study, the anti-GBM effect of ESC-exos is confirmed and then c(RGDyK)-modified and paclitaxel (PTX)-loaded ESC-exos, named cRGD-Exo-PTX are prepared. It is then investigated whether the engineered exosomes deliver more efficiently to GBM cells versus free drug alone and drug-loaded ESC-exos using an in vitro GBM model and in vivo subcutaneous and orthotopic xenografts model. The results show that cRGD-Exo-PTX

significantly improves the curative effects of PTX in GBM via enhanced targeting. These data indicate that ESC-exos are potentially powerful therapeutic carriers for GBM and could have utility in many other diseases.

DSPE-PEG2000-cRGDyK 由 DSPE（1,2-二硬脂酰-sn-甘油-3-磷酸乙醇胺）、PEG2000（聚乙二醇 2000）和 cRGDyK（含有精氨酸-甘氨酸-天冬氨酸序列的环肽）组成。DSPE 赋予产品良好的膜亲和性，PEG2000 提供亲水性和稳定性。而 cRGDyK 能特异性识别并结合整合素受体。可用于构建靶向tumor的纳米化合物载体，通过 cRGDyK 与tumor细胞表面高表达的整合素受体结合，实现化合物的靶向递送。外泌体是一种纳米大小的膜囊泡（30-100纳米），可以被靶配体修饰。ESCs分泌的外泌体（ESC-exos）具有抗tumor特性。引用的文件中提到c（RGDyK）修饰和紫杉醇（PTX）负载的ESC-exos，命名为cRGD-Exo-PTX就具有次特性。制备过程如下：

图：偶联c（RGDyK）肽和PTX加载到ESC-exos中的示意图

Tumor靶向外泌体的制备

c（RGDyK）通过插入后方法纳入ESC-exos中将1,2-二茶酰-sn-甘油-3-磷酸乙醇胺-N-[甲氧基（聚乙二醇）-2000]-c（RGDyK）（DSPE-PEG2000-cRGDyK）溶解在4-（2-羟乙基）-1-哌嗪乙磺酸缓冲液中，形成胶束。然后，将ESC-exos悬浮液与上述悬浮液在混合。冷却到室温后，外泌体立即通过尺寸排除层析纯化，得到crgd修饰的外泌体（cRGD-exos）。然后，通过共孵育法将PTX装载到外泌体中。将PTX溶解在浓度的二甲亚砜中。然后，将上述溶液与外泌体或cRGD-exos悬液混合。将混合物在室内孵育。最后，用超离心法纯化PTX负载的外泌体。

图：免疫组化分析检测不同化合物TUNEL和Ki-67表达的代表性图像。

结论：体内外均证实了ESC-exos对GBM的抑制作用。通过体外GBM模型和体内皮下和原位异种移植模型，研究工程外泌体是否比单独使用游离化合物和载药ESC-exos更有效地传递给GBM细胞。DSPE-PEG2000-cRGDyK参与制备的cRGD-Exo-PTX通过增强靶向性，提高了PTX对GBM的效果。然后将ESC-exos与tumor靶向c（RGDyK）肽偶联，并同步装载PTX。工程外泌体，命名为cRGD-ExoPTX，被证明具有良好的GBM靶向能力，并提高了PTX在GBM模型中的效果。