新型高效线粒体靶向多功能脂质体抗癌药物传递系统研究

The lack of stealth, poor stability and non-targeting to organelle are the main problems that liposome-based antitumor drug delivery systems faced. In this project, a novel multifunctional drug delivery system (DDS) based on modified phospholipids was fabricated. Cross-linkable phospholipids were synthesized based on the distearoylphosphatidylethanolamine (DSPE) and sulphydryl compounds. Charge reversal and mitochondrion targeting phospholipids were synthesized based on DSPE, mitochondrion targeting peptide and maleic hydride. The modified phospholipids, natural phospholipids and cholesterol were self-assembled to multifunctional liposomal DDS. This liposomal DDS possessed stealth, good stability, tumor microenvironmental sensitivity and mitochondrion targeting. These integrated functions were expected to resolve the problems that liposomal DDS faced and enhance the antitumor efficacy. The implantation of this project would achieve a novel multifunctional liposomal DDS. It would provide a new strategy for the design and construction of antitumor DDS to promote the development of chemotherapy for cancer.

项目针对脂质体抗癌药物传递系统面临的无隐形功能、稳定性差、无细胞器靶向性等主要问题，设计构建一类基于改性磷脂的新型多功能药物传递系统。以生物相容性好的二硬脂酰基磷脂酰乙醇胺（DSPE）与含巯基化合物构建具有可二硫键交联和细胞内环境敏感的改性磷脂；DSPE、线粒体靶向肽和马来酸酐共同构建具有电荷翻转和线粒体靶向功能的改性磷脂。以上述改性磷脂、天然磷脂和胆固醇，通过自组装，构建同时具有隐形、高稳定性、肿瘤微环境敏感、线粒体靶向的多功能脂质体药物传递系统。利用二硫键交联结构、血液循环中脂质体呈负电荷、在肿瘤弱酸性环境脂质体电荷翻转为正电荷、细胞内高浓度谷胱甘肽破坏二硫键以及(KLAKLAK)2多肽等多种因素共同作用，克服脂质体抗癌药物传递系统面临的诸多问题，实现高效抗癌效果。通过本项目的实施，将获得一类新型的多功能脂质体纳米药物传递系统，为研发具有临床应用前景的脂质体抗癌药物传递系统奠定基础。

该项目成功构建了三种新型的抗癌药物脂质体纳米传递系统，分别是具有肿瘤细胞外微环境弱酸性（pHe 6.8）响应的二硬脂酰磷脂酰（DSPE）-赖氨酸（Lys）-二甲基马来酰胺（DMMA）脂质体；具有pHe响应性、电荷翻转、线粒体靶向和隐形功能的DSPE-KLA-DMMA脂质体以及具有肿瘤细胞和肿瘤新生血管内皮细胞线粒体双靶向功能的RGD/KLA-DSPE-PEG脂质体。系统研究了磷脂结构、组成、性能对脂质体粒径、电位、载药性能、释药性能、pHe响应性、血浆中稳定性、非特异性蛋白吸附等理化性质的影响。选用小鼠乳腺癌细胞系（4T1）、人肺癌细胞系（敏感型A549和耐药型A549/TAXOL）、人脐静脉上皮细胞（原代HUVEC），在细胞和分子水平研究阐明了脂质体结构、组成、性能等对入胞途径、胞内分布、线粒体介导的凋亡途径、细胞增殖抑制的影响规律。构建了Blb/C荷瘤小鼠模型（敏感型和耐药型肿瘤），在动物水平，阐明了脂质体组成和性能对抑制肿瘤生长、克服肿瘤多药耐药性、抑制肿瘤血管新生的影响规律。阐明了改性磷脂材料、脂质体与肿瘤作用的机理，提出对肿瘤具有突出治疗效果的载药脂质体的设计与制备原理，建立了相应的制备方法和调控技术，获得了一系列具有我国自主知识产权的新型磷脂材料和脂质体药物，为拓展脂质体在肿瘤治疗中的应用，促进生物医用材料的发展奠定基础。圆满完成了项目计划任务书所规定的研究内容，达到了预期研究目标。