原文献：Galactose-Modified PH-Sensitive Niosomes for Controlled Release and Hepatocellular Carcinoma Target Delivery of Tanshinone IIA

文献链接：https://pubmed.ncbi.nlm.nih.gov/33694067/

作者：Xixi Hu, Jun Zhang, Lulu Deng,Hao Hu,Junjie Hu and Guohua Zheng

摘要：Increasing the drug tumor-specific accumulation and controlling their release is considered one of the most effective ways to increase the efficacy of drugs. Here, we developed a vesicle system that can target hepatoma and release drugs rapidly within tumor cells. This non-ionic surfactant vesicle is biodegradable. Galactosylated stearate has been used to glycosylate the vesicles to achieve liver targeting; replacement of a portion (Chol:CHEMS = 1:1) of cholesterol by cholesteryl hemisuccinate (CHEMS) allows for a rapid release of drugs in an acidic environment. In vitro release experiments confirmed that galactose-modified pH-sensitive niosomes loaded with tanshinone IIA had excellent drug release performance in acid medium. In vitro experiments using ovarian cancer cells (A2780), colon cancer cells (HCT8), and hepatoma cell (Huh7, HepG2) confirmed that the preparation had specific targeting ability to hepatoma cells compared with free drugs, and this ability was dependent on the galactose content. Furthermore, the preparation also had a more substantial inhibitory effect on tumor cells, and subsequent apoptosis assays and cell cycle analyses further confirmed its enhanced anti-tumor effect. Results of pharmacokinetic experiments confirmed that the vesicle system could significantly extend the blood circulation time of tanshinone IIA, and the larger area under the curve indicated that the preparation had a better drug effect. Thus, the results of biodistribution experiments confirmed the in vivo liver targeting ability of this preparation. Niosomes designed in this manner are expected to be a safe and effective drug delivery system for liver cancer therapy.

半乳糖化囊泡的传统方法是连接囊泡表面的糖蛋白。然而，这种外源性生物大分子靶向配体的分子量较高，导致制备的囊泡颗粒尺寸过大，不利于靶向肝细胞。此外，它还能引起身体潜在的免疫反应。因此，合成一种半乳糖基化的两亲性脂质，半乳糖基化的硬脂酸盐所构成的囊泡系统。设计一种低分子量脂质半脂糖化硬脂酸盐（Gal）作为核小体的修饰。该配体的结构类似于非离子表面活性剂的形成，具有水溶性头部和脂溶性尾巴，因此可以有序地排列在双分子层。半乳糖修饰的粒体是用这种配体制备的，脂溶性尾部（通常是长链脂肪酸）在非离子表面活性剂的双分子层“有序排列”，而水溶性半乳糖头倾向于面对水相的一侧。水溶性头部暴露于双分子层表面，可被肝细胞膜上的唾液糖蛋白受体（ASGPR）特异性识别，介导肝细胞内吞作用，从而内化细胞内的半乳糖化的大分子。生产一种唾液糖蛋白配体修饰剂，可以通过脂肪酶将半乳糖和硬脂酸乙烯酯化连接到囊泡表面（Novozym 435）生成半乳糖化硬脂酸盐。制备反应式如下图所示：

半乳糖修饰ph敏感丹参酮IIA载体的制备

将丹参酮的IIA、Span80、胆固醇、CHEMS和半乳糖化硬脂酸酯（摩尔比为1：30：15：15：15：6）放在烧杯中，用乙醇完全溶解。用注射器将乙醇溶液缓慢、均匀地注射入PBS（pH 7.38）中，恒温搅拌。将溶液搅拌一段特定的时间，直到乙醇完全蒸发，当浓缩水合物的温度达到室温后，用超声波电池破碎机将溶液均质，接下来，用脂质体挤出机减少囊泡的颗粒大小。最后，将挤压溶液置于灭菌离心管中，获得装载丹参酮IIA的靶向体。装载丹参酮IIA的靶向体缩写为：半乳糖修饰（Gal）-pH敏感性（pH）-丹参酮IIA（TanIIA）-简单非离子表面活性剂囊泡（NSVs）。

图：半乳糖

结论：体外释放实验证实，半乳糖化硬脂酸酯参与制备的丹糖酮IIA的半乳糖修饰的ph敏感微粒体在酸性培养基中具有良好的化合物释放性能。进行体外实验，与游离化合物相比，该制剂对cancer cell具有特异性的靶向能力，这种能力取决于半乳糖含量。此外，该制剂对tumor cell也有抑制作用，随后的细胞Apoptosis 试验和细胞周期分析进一步证实了其增强的抗tumor作用。化合物代动力学实验结果证实，囊泡系统能延长丹参酮IIA的循环时间。