文献：Anticancer Efficacy of Targeted Shikonin Liposomes Modified with RGD in Breast Cancer Cells

文献链接：https://pubmed.ncbi.nlm.nih.gov/29382149/

作者：Xianchun Wen, Jiping Li, Defu Cai, Liling Yue, Qi Wang, Li Zhou, Li Fan , Jianwen Sun,Yonghui Wu

相关产品：DSPE-PEG2000-RGD 磷脂-聚乙二醇2000-RGD穿膜肽

原文摘要：Shikonin (SHK) has been proven to have a good anti-tumor effect. However, poor water solubility and low bioavailability limit its wide application in clinical practice. In this study, to overcome these drawbacks, RGD-modified shikonin-loaded liposomes (RGD-SSLs-SHK) were successfully prepared. It exhibited excellent physicochemical characteristics including particlesize,

zeta potential, encapsulation efficiency, and delayed release time. Meanwhile, the targeting activity of the RGD-modified liposomes was demonstrated by flow cytometry and confocal microscopy in the αvβ3-positive MDA-MB-231 cells. Besides exhibiting greater cytotoxicity in vitro, compared with non-targeted shikonin-loaded liposomes (SSLs-SHK), RGD-SSLs-SHK could also evidently induce apoptosis by decreasing the expression of Bcl-2 and increasing the expression of Bax. It could also inhibit cell proliferation, migration, invasion, and adhesion by reducing the expression of MMP-9 and the level of NF-κB p65, but did not affect the expression of MMP-2 in the MDA-MB-231 cells. Therefore, these findings indicated that the strategy to use RGD-modified liposomes as carriers for targeted delivery of shikonin is a very promising approach to achieve breast cancer targeted therapy.

DSPE-PEG2000-RGD是一种具有特殊结构和功能的化合物，DSPE-PEG2000-RGD具有良好的化合物载体潜力，通过将其与化合物结合，可实现化合物的定向传递和控释。在tumorTreatment 、等领域具有优势。紫草素（SHK）具有良好的抗tumor作用。然而，由于水溶性差和生物利用度低，限制了其在临床实践中的应用。为了克服这些缺点，制备了RGD修饰的紫草素脂质体（RGD-SSLs-SHK）。它具有良好的物理化学特性，包括粒径、zeta电位、封装效率和延迟释放时间。以下为具体制备过程：

图为：RGD修饰的紫草素负载脂质体（RGD-SSLs-SHK）的示意图

DSPE-PEG2000-RGD在脂质体RGD-SSLs-SHK制备中的应用：

采用薄膜水化法制备脂质体。通常，EPC、胆固醇、DSPE-PEG2000和SHK的混合物首先溶解在二氯甲烷：乙醇中，放在圆底烧瓶中。随后，在真空下旋转蒸发去除有机溶剂，干燥的脂质膜用PBS或超纯水水合，直到充分溶解，经过超声。然后将悬浮液分散并挤压至聚碳酸酯膜，然后在G-50柱上进行凝胶过滤，以去除未封装的SHK。最后，形成SHK负载脂质体（SSLs-SHK）。同样，EPC、胆固醇、DSPE-PEG2000、DSPE-PEG2000-RGD和SHK的混合物通过上述程序形成了RGD修饰的脂质体（RGD-SSLs-SHK）。采用相同的方法制备装载cou香豆素6（Cou6）的脂质体，以及不添加Cou6或SHK的空白脂质体代替SHK。

图为：SSLs-SHK、RGD-SSLs-SHK和游离SHK在体外累积释放

结论：DSPE-PEG2000-RGD结合了DSPE的磷脂特性、PEG的亲水性和RGD肽的靶向性。RGD肽作为整合素和其配体相互作用的识别位点，能够介导细胞与细胞外基质及细胞间的黏附作用，并具有信号传导功能。因此，DSPE-PEG2000-RGD修饰的脂质体RGD-SSLs-SHK能够主动识别ανβ3整合素受体，增加细胞对脂质体RGD-SSLs-SHK的摄取，从而进一步增加tumor细胞内的化合物浓度，实现化合物的靶向递送。DSPE-PEG2000部分兼有了磷脂的两亲性和PEG的亲水高分子特性，这使得DSPE-PEG2000-RGD修饰的脂质体RGD-SSLs-SHK在生物体内具有良好的稳定性和长循环性。PEG链段能够在脂质体表面形成一层水化膜，减少脂质体与plasma中蛋白、酶等成分的结合，从而延长脂质体在体内中的循环时间。