文献：UTMD promoted local delivery of miR-34a-mimic for ovarian cancer therapy

文献链接：https://xueshu.baidu.com/usercenter/paper/show?paperid=1t3c0tw0md6k0xd0461w02x0q7648118&site=xueshu_se

作者：Yue Li, Meng Du, Jinghui Fang , Jia Zhou and Zhiyi Chen

相关产品：DSPE-PEG2000-FA 磷脂-聚乙二醇2000-叶酸

原文摘要：MicroRNA-mediated gene therapy is emerging as a promising method for the treatment of ovarian cancer, but the development of miRNA mimic delivery vectors is still in its infancy, where the safety and efficacy of miR-34a-mimic remain unknown. Ultrasound-targeted microbubble destruction (UTMD) can be an effective and minimally invasive tool for the delivery of miR-34a-mimic in vitro and in vivo. Here, we describe a high-efficiency gene delivery strategy by using miR-34a-mimic loaded folate modified microbubbles (miR-34a-FM) with a portable ultrasonic irradiation system. Ultrasonic parameters, including acoustic intensity (AI), exposure time (ET) and duty cycle (DC), were optimized and the optimal acoustic condition (1.0 W/cm2 , 20 s, and 15% DC) was used to deliver miRNA-34a into cells in vitro. MiR-34a mimic was successfully introduced into the cytoplasm and was found to inhibit proliferation and induce apoptosis of SK-OV-3 cells. Next, miR-34a-mimic was delivered to tumor tissue via UTMD, inhibiting tumor growth and prolonging the survival time of mice. In summary, UTMD-mediated miR- 34a-mimic delivery has potential application in the clinical treatment of ovarian cancer.

DSPE-PEG2000-FA以DSPE-PEG2000为基础，DSPE提供了疏水性部分，可与脂质环境相互作用，而PEG2000赋予材料良好的亲水性和稳定性，减少体内非特异性吸附。叶酸作为一种靶向配体，赋予了该材料主动靶向的能力。它可以用于制备纳米脂质体或胶束等载体，将疏水性化合物包裹在内部，借助PEG2000的特性在体内循环中稳定存在。同时，叶酸基团能够特异性地识别叶酸受体高表达的细胞，从而实现靶向性，提高化合物在靶部位的浓度，增强效果，该文献描述了一种基因传递策略，通过使用miR-34a模拟负载叶酸修饰微气泡（miR-34a-FM）和便携式超声辐照系统。过程如下：

图：叶酸受体修饰的微气泡的制备示意图

脂包被miR-34a模拟FA-MBs的制备

脂质涂层超声造影剂按照之前描述的制备阳离子MBs的方案制备。简而言之，利用DSPE-PEG2000-FA将二棕榈酰磷脂酰胆碱（DPPC）（AL，AL）和1,2-二棕榈酰-3-三甲甲基丙烷与氯仿混合，生成FA受体靶向MBs（FM）。在水浴中干燥，在玻璃瓶底部产生脂膜，然后，用甘油杜尔贝科磷酸盐缓冲盐水混合物水合脂质膜。随后，将miR-34a-mimic加入到脂质膜复合物中，并将混合物脱气并重新填充全氟丙烷（C3F8）。miR-34a-mimic-FA-MBs（miR- 34a-FM）通过使用搅拌器强烈机械摇晃然后离心分离未附着的模拟物。

图：miR-34a-FM的大小和浓度

结论：DSPE-PEG2000-FA参与制备了一种miR- 34a-mimic联合叶酸受体修饰的MBs（miR-34a-FM）的策略。miR-34a-mimic利用UTMD快速触发介导基因传递的细胞膜穿孔，可应用于oophoroma细胞。参数的优化和设备的改进提高了基因传递效果。在oophoroma细胞中过表达miR-34a，证实了下调Notch1的表达可激活细胞Apoptosis通路，阻止细胞细胞迁移。