肝星状细胞靶向的时空稳定可控的类脂质囊泡用于复合siRNA治疗肝纤维化的研究

Hepatic stellate cell (HSC) is a therapeutic target for hepatic fibrosis, because the activation and proliferation of HSC plays a dominant role in the pathological process of hepatic fibrosis. In this project, an amphiphilic hyperbranched thiol lipoid (Cn-PASH) and a long circulation targeting ligand, vitamin A-polyethylene glycol-cholesterol (VA-PEG-Chol), were designed and synthesized. Cn-PASH and VA-PEG-Chol integrated into a controlled spatiotemporal stable lipoid vesicle for the targeting delivery of two kinds of small interfering RNAs (siRNAs), siHSP47 and siTIMP-1, towards HSC. VA on the surface of the vesicle bound with the retinol-binding protein (RBP) in blood, and then the vesicle entered HSC through receptor-mediated internalization by RBP receptor. The PEGylation and disulfide bonds crosslinking of the vesicle protected siRNAs against degradation as well as reinforced its controlled spatiotemporal stability, and the tertiary amine groups of the vesicle helped siRNAs escape from endosome via the proton sponge effect. At last, the lipoid vesicle was decomposed by the intracellular higher concentration of glutathione in the HSC, which accelerated the release of siHSP47 and siTIMP-1, and reduced the expression levels of heat shock protein 47 (HSP47) as well as tissue inhibitor of metalloproteinase 1 (TIMP-1). As a result, the treatment of hepatic fibrosis was achieved by the decreased synthesis and accelerated degradation of extracellular matrix of HSC. The lipoid vesicle presented in this project can deliver combinational siRNAs into HSC specifically, and with further development it can serve as an innovative, safe and efficient vehicle platform for the anti-hepatic fibrosis therapy.

肝星状细胞（HSC）的激活和增生是肝纤维化发生衍化的中心环节，抑制HSC激活并诱导其逆转对肝纤维化治疗意义重大。本项目在前期研究基础上设计合成了两亲性巯基化类脂质和维生素A-聚乙二醇-胆固醇两种新颖的载体材料，并利用自组装方法制备了包载复合siRNA（siHSP47和siTIMP-1）的时空稳定可控的类脂质囊泡。该囊泡表面维生素A与血液中视黄醇结合蛋白（RBP）复合可识别HSC上RBP受体而实现靶向HSC的递送；PEG化和二硫键穿插的“铠甲”可保护siRNA免受破坏并实现其时空稳定可控，囊泡中的叔胺通过“质子海绵”使siRNA逃逸内涵体至细胞质，胞质中较高浓度的谷胱甘肽可断裂二硫键释放复合siRNA沉默热休克蛋白47（siHSP47）和基质金属酶抑制因子（siTIMP-1）发挥“前阻后降”的治疗效果。本项目制备的靶向递送复合siRNA的类脂质囊泡，为肝纤维化的治疗提供安全、高效的载体平台。

肝星状细胞（HSC）的激活和增生是肝纤维化发生衍化的中心环节，抑制HSC激活并诱导其逆转对肝纤维化治疗意义重大。本项目在前期研究基础上设计合成了两亲性巯基化类脂质和维生素A-聚乙二醇-胆固醇两种新颖的载体材料，并利用自组装方法制备了包载复合siRNA（siHSP47和siTIMP-1）的时空稳定可控的类脂质囊泡。该囊泡表面维生素A与血液中视黄醇结合蛋白（RBP）复合可识别HSC上RBP受体而实现靶向HSC的递送；PEG化和二硫键穿插的“铠甲”可保护siRNA免受破坏并实现其时空稳定可控，囊泡中的叔胺通过“质子海绵”使siRNA逃逸内涵体至细胞质，胞质中较高浓度的谷胱甘肽可断裂二硫键释放复合siRNA沉默热休克蛋白47（siHSP47）和基质金属酶抑制因子（siTIMP-1）发挥“前阻后降”的治疗效果。本项目制备的靶向递送复合siRNA的类脂质囊泡，为肝纤维化的治疗提供安全、高效的载体平台。