载中药双组分的功能化中空介孔二氧化硅递送系统的构建及抗肿瘤机制的研究

For cancer therapy by traditional Chinese medicine, Curcuma and Astragalus membranaceus were always used in combination. Based on the matching principle of them which aims to “promoting circulation of qi while nourishing one’s vitality”, a multi-functionalized and degradable hollow mesoporous silica nanoparticles (HMSNs) was innovatively designed as carriers of β-elemene and Astragalus polysaccharides which are active components extracted from Curcuma and Astragalus membranaceus, respectively. And the novelty of this research mainly lies in 1)The morphology and pore structure of HMSNs could be adjusted to achieve high drug loading and stability. 2)By introducing the disulfide containing organosiloxane into the skeleton of HMSNs, the degradation rate of carrier and the release kinetics of the drug molecules could be well controlled. 3)Furthermore, a zwitterionic poly-lysine was synthesized and modified on the surface of the carrier in order to reduce the burst release of drug and facilitate the activation of carrier under the mild acidic tumor microenvironment thus achieving the specific uptake of drug delivery systems by tumor cells. 4) Since β-elemene could inhibit tumor proliferation and astragalus polysaccharides could promote immunity, by co-delivery of these two components to the tumor area could achieve chemo-immunotherapy with enhanced therapeutic efficacy. Moreover, techniques from cytology and immunology will be applied to further optimize the synergistic regimen and illuminate the molecular mechanism behind the synergistic effect of β-elemene and astragalus polysaccharides. This present research provided innovative ideas for developing drug delivery systems to co-encapsulate multiple active components of traditional Chinese medicine with distinct properties, and specifically delivering them to the tumor area achieving chemo-immunotherapy. And this study will also help to enlighten the scientific connotation of matching principle in traditional Chinese medicine.

在癌症的中医治疗中，莪术与黄芪配伍能够发挥“行中有补，补中有行”的效果，研究根据此配伍原则，创新性地设计了功能化可降解型中空介孔二氧化硅（HMSNs）作为莪术的有效成分β-榄香烯和黄芪的有效成分黄芪多糖的载体，1）通过调整载体的形貌、介孔孔道结构以实现不同中药成分的高效装载与稳定分散。2）将含二硫键的有机硅氧烷掺入到载体骨架中以调控载体降解速率和药物释放速率；3）在载体表面进一步修饰两性聚赖氨酸，在减少药物突释的同时，使递送系统在肿瘤弱酸性的微环境中活化，从而被肿瘤细胞所特异性摄取。4）将β-榄香烯和黄芪多糖共同递送至肿瘤组织，在杀伤肿瘤细胞的同时改善其免疫抑制的微环境，提高治疗效果。利用细胞学及免疫学研究手段进一步优化β-榄香烯和黄芪多糖的配伍方案，同时阐明其联合增效的分子机制。研究为构建载中药多组分的肿瘤微环境响应型递送系统，实现协同增效，以及探索中药配伍的科学内涵提供新的借鉴和思路。

在癌症的中医治疗中，莪术与黄芪经常配伍使用。研究将二者的主要成分β-榄香烯（ELE）与黄芪多糖（APS）共同装载于长循环脂质体中，构建了ELE/APS-LCL。根据体外结果，APS未能提高ELE对肺癌肿瘤细胞的毒性。体内药效学结果显示ELE对肿瘤生长的抑制作用不显著，而且与APS没有表现出协同作用。机理研究发现ELE无法诱导LLC细胞产生ICD效应，还会阻碍CD8+T淋巴细胞的增殖。而APS对DC的熟化、CD8+T淋巴细胞的增殖与迁移以及抗肿瘤细胞因子的分泌均无促进作用，说明ELE与APS不能通过激活和增强免疫，发挥协同抗肿瘤作用。. 为了提高ELE的抗肿瘤效果，研究制备了共载ELE与光敏剂（IR780）的长循环脂质体（IR780-ELE-LCL）。IR780-ELE-LCL在近红外激光的照射下，表现出良好的光热和光动力效果。体外细胞毒结果显示，IR780-ELE-LCL在激光照射下能够显著提高对LLC肿瘤细胞的杀伤力。另外，IR780-ELE-LCL能够利用EPR效应提高化疗药物和光敏剂在小鼠肿瘤组织中的分布。体内药效学结果证明，IR780-ELE-LCL能够实现光-化疗联合治疗，提高抗肿瘤疗效，而且安全性良好。. 为了构建肿瘤微环境响应的纳米给药系统，研究制备了载ELE的PLGA纳米粒，通过预先包覆的聚单宁酸（pTA）在纳米粒表面进一步修饰了聚赖氨酸（PLL），制得ELE-PLGA-pTA-PLL。虽然该纳米粒能够根据环境pH改变自身的表面电位，但纳米粒的细胞摄取却没有差别，未达到预期。实验中发现pTA具有良好的光热转化能力，是一种理想的光热材料。因此，研究制备了ELE-PLGA-pTA纳米粒，在近红外激光的照射下，pTA表现出良好的升温效果和光稳定性。体、内外实验结果显示ELE-PLGA-pTA能够实现光热-化疗相结合，显著提高对LLC肿瘤细胞的杀伤力，并且提高抗肿瘤效果。