靶向CAFs的中药脂质体构建及联用抗肝癌脂质微乳复合系统促渗增效作用研究

Carcinoma-associated fibroblasts (CAFs) is a critical tumor-promoted factor in the hepatocellular carcinoma microenvironment. CAFs-induced interstitial tissue hyperplasia in tumor microenvironment leads to the barrier to deep penetration of traditional Chinese medicine (TCM) nano-delivery, resulting in a decreased anti-tumor efficacy. CAFs regulated with TCM component precisely can not only effectively improve the delivery efficiency of nano-formulations, but also inhibit tumor-promoted activity of CAFs, exhibiting an effective strategy to enhance antitumor effects. Based on the previous studies, oxymatrine was capable of reducing the activation of CAFs and liver fibrosis significantly, but still faced challenges in the selective biodistribution. Herein, a FH peptide-modified oxymatrine liposome was developed in this project, which could reduce the interstitial tissue hyperplasia and fibrosis in the hepatocellular carcinoma after administration throughout the treatment. In addition, the icaritin-coix seed oil lipid-microemulsion complex system was introduced in the later stage of the treatment, which could release small-sized microemulsion, and thereby deep penetration of active TCM ingredients to realize a synergistic effect. This study used two-photon laser confocal microscopy and other advanced technologies to multidimensionally characterize the tumor microenvironment, and as well explore the synergistic mechanism of combinational therapy. The project provides a new idea and strategy for improving antitumor efficacy of traditional Chinese medicine nano-delivery systems.

肿瘤相关成纤维细胞（CAFs）是肝肿瘤微环境中重要的促瘤因素，由其引发的肿瘤间质增生和高度纤维化也是导致中药纳米制剂难以深层渗透至瘤内及抗癌药效难以提升的重要原因。精准干预CAFs的生物功能不仅可以抑制其促瘤活性，还能有效改善纳米药物的递送效率，是提高药物疗效的有效策略。前期研究发现，氧化苦参碱可显著降低CAFs活化和肝纤维化但存在体内分布无选择性的缺陷。因此本项目拟采用FH肽修饰技术构建一种可精准靶向CAFs的氧化苦参碱脂质体作为全程干预药物，降低肿瘤间质增生及纤维化程度，畅通递药通道；之后联用课题组前期研究较为成熟的淫羊藿素-薏苡仁油脂质微乳复合系统，将活性组分递送至肿瘤更深层，提升协同抗肝癌药效。本项目还将借助双光子激光共聚焦成像等先进技术多维表征肿瘤微环境特性，剖析联合给药协同增效机制。本项目研究从精准干预CAFs角度为提高中药纳米制剂深层递送及抗肿瘤疗效提供了全新的思路和方法。

肝肿瘤微环境中存在着丰富的肿瘤相关成纤维细胞（CAFs），可引发大量胶原蛋白沉积和支架蛋白重塑，造成组织致密及渗透压升高，是阻碍中药纳米制剂瘤内渗透和疗效发挥的主要原因。针对上述问题，本项目设计构建一种精准靶向CAFs的氧化苦参碱脂质体(CFH/OM-L），通过干预CAFs降低瘤内间质增生，打通递药通道，形成抑瘤微环境；联用抗肝癌淫羊藿素-薏苡仁油脂质微乳复合系统(IC-ML)，以提高抗肝癌疗效。.1、合成了可靶向CAFs的脂质材料，制备了CFH/OM-L，粒径为125nm，电位为-38 mV，包封率和载药量分别为87.12%和2.08%，稳定性良好，且具有缓释效应。CFH/OM-L通过网格蛋白和小窝蛋白介导途径被CAFs摄取，且摄取量显著高于裸药和普通脂质体。该脂质体可降低CAFs特征蛋白Vimentin和α-SMA的表达，调控上皮间质转化抑制CAFs活化和胶原分泌。该脂质体具有优异的肝肿瘤组织靶向性，对肿瘤组织深层的CAFs渗透能力较强，可以促进纳米粒瘤内深层渗透。.2、制备了IC-ML，粒径为81 nm，电位为-30.00 mV，具备微乳包封于脂质体的结构特征。体外释放符合温敏特征。IC-ML通过网格蛋白介导途径被HepG2摄取且摄取量显著高于裸药和微乳。IC-ML 能较好的抑制HepG2细胞及其3D细胞瘤球增殖，显著诱导其凋亡并阻滞细胞周期于G1/G0期，且渗透性能优于微乳。IC-ML可延长药物在体内的循环、增加制剂在肿瘤部位蓄积。IC-ML具有较好的体内抗肿瘤作用，肿瘤出现明显坏死和凋亡；可通过HIF-1α-VEGF轴抑制肿瘤血管异常生成，改善瘤内免疫抑制微环境。此外，血常规指标、肝脾指数、肝肾功能等指标结果均表明该制剂对小鼠无明显毒性。.3、 CFH/OM-L与IC-ML联合给药在肝癌异位瘤模型上表现出最强的抑瘤率，且有效延长荷瘤裸鼠的生存时间。联合给药组的肿瘤组织出现了明显组织坏死和凋亡，肿瘤细胞增殖能力最弱；肿瘤中CAFs和胶原的生成被抑制，上皮间质转化过程被逆转。各实验组血常规指标、肝脾指数、肝肾功能指标、主要脏器H&E染色结果均未见明显异常，表明联合给药的安全性较好。.本项目共发表论文11篇，单篇最高影响因子9.4。申请专利并获得授权1项，获得省级科技奖励2项，培养研究生3名。为提升中药多组分纳米给药系统递药效率和抗肿瘤疗效提供了全新思路和方法。