丹参-甘草不同极性组分受体介导肝主动靶向脂质体构建评价及共性问题探讨

The couplet medicines Salvia Miltiorrhiza - Liquorice derive from the clinical. Studies have shown that the conjunction of them can shorten the normalization time of liver function, reduce harmful side effects and produce synergy effects. Depending on their properties of being dissolved in phospholipid bilayer and inner aqueous phase of the liposomes respectively, this project creatively choose salvianolic acid B, tanshinone IIA and glycyrrhetinic acid which have different polarties, anti-hepatic fibrosis action pathways and mechanisms to be included into the liposomes. This kind of liposomes can increase the quantity of drug loading and increase drug effects. To increase the targeting rates to hepatic parenchymal cells of liposomes, we link glycyrrhetinic acid to the surface of the liposomes as a hepatic targeting molecule. Meanwhile, key elements such as size, surface morphology, envelop rate etc. are studied to determine the best preparation methods. Then the quality, pharmacokinetics, liver target and in vitro efficacy of the liposome are studied systematically. This project is expected to provide new ideas to the combination of TCM theory and novel drug delivery systems and to the synergistic therapeutic effects of multiple components. It is also expected to provide experimental foundation for the exploration of common problem of new anti-hepatic fibrosis hepatic active targeting liposomes.

丹参－甘草为来源于临床的肝纤维治疗药对，研究表明二者联合使用可缩短肝功能复常时间，减少副作用，产生协同增效的效果。本课题首次选择丹参－甘草中的丹参酚酸B、丹参酮IIA和甘草次酸三种不同极性、抗肝纤维化作用显著但作用环节、作用机理不同的单体药物，利用三者分别相溶于脂质体磷脂双分子层和内水相的特性，同时将三者包载于脂质体中，以增加脂质体的总体载药量，使其产生抗肝纤维化的协同增效作用；同时选择甘草次酸作为脂质体主动靶向肝实质细胞的导向分子，结合于脂质体表层，提高脂质体肝实质细胞靶向性。通过探讨影响脂质体粒径及其分布、表面形态、载药量、包封率以及体外渗透率的关键因素，确定最佳制备方法，并对脂质体质量、体内药代动力学、肝靶向性及体外药效进行系统研究。通过本课题的研究，为促进中医药理论与新型给药系统结合提供新的研究思路，并为探讨新型抗肝纤维化主动肝靶向高效脂质体的共性问题提供实验依据。

作为药物载体与其他剂型相比，脂质体拥有诸多优点，但由于受到载药量、包封率等因素的影响，脂质体所载药物多为单一成分，载药负荷低。目前未见有将不同极性、协同作用的三种组分分别承载于脂质体脂膜及内水相中，以提高脂质体总体载药量，利于药物到达靶器官，且链接主动靶向肝实质细胞的配体起到介导作用的肝主动靶向多成分复方脂质体相关研究。.本课题制备得到的复方脂质体(GTS-lip)工艺稳定、重现性好，三种药物Sal B、TSN和GA包封率均达80%以上，粒径控制在100~200nm，实现了不同极性三组分共同包载于脂质体的工艺。同时，合成具有疏水端和亲水端的两亲性导向配体3-琥珀酸-30-硬脂醇甘草次酸酯 (18-GA-Suc)，将18-GA-Suc掺入该复方脂质体作为靶头，制备甘草次酸衍生物受体介导的主动靶向脂质体（Suc-GTS-lip），以期提高药物的肝靶向性。该工艺稳定可控。.静注给药的药代动力学结果显示，与溶液组相比，脂质体组中Sal B的AUC由20.37±1.58 μg·h ·mL-1增至636.06±27.73 μg·h ·mL-1，MRT由0.28±0.01 h延长至1.97±0.09 h，TSN的AUC也有一定程度增加；比较GTS-lip与Suc-GTS-lip，SalB的AUC由636.06±27.73 µg·h·mL-1降至550.39±12.34 µg·h·mL-1，TSN的AUC由1.08±0.72 µg·h·mL-1降至0.65±0.04 µg·h·mL-1 ，GA的AUC由43.64±3.10 µg·h·mL-1增至96.21±3.75 µg·h·mL-1，说明配体的掺入改变了脂质体中三种药物在小鼠体内的生物利用度。.肝组织分布药动学参数显示，GTS-lip中Sal B、TSN、GA在肝组织中的AUC分别是普通溶液的2.11、9.07、2.59倍，Cmax分别是普通溶液的1.76、2.08、1.73倍，提示脂质体能够同时提高三种药物的肝靶向性。Suc-GTS-lip组在肝脏中SalB的AUC为26.03±4.66µg·h·mL-1，Cmax为22.40±3.15µg·mL-1，分别是GTS-lip组的10.21倍和4.44倍；相较于Suc-GTS-lip组的其他脏器，肝脏中SalB的AUC分别为脾、肺、肾中的AUC的1.35倍、1.95倍、4.70倍。