靶向纳米钻石-甲氨蝶呤药物体系制备及与MCF-7细胞作用

Preparation of Targeting Nanodiamond-metaminopterone Drug System and Its Interaction with MCF-7 Cells

以羧基化纳米钻石(ND-COOH)为基体,通过共价键合方法将聚乙二醇二胺(H2N-PEG-NH2)、叶酸(FA)和缩水甘油(GLY)偶联于ND-COOH表面,赋予纳米钻石载体较好的水溶分散性和靶向性,借助氢键和范德华力等作用力负载甲氨蝶呤(MTX),得到靶向纳米钻石-聚乙二醇二胺-叶酸/缩水甘油/甲氨蝶呤(ND-PEG-FA/GLY/MTX NPF/G/M)纳米药物体系.采用透射电子显微镜、 X射线能量色散谱、粒径及电位测试证实已制备NPF/G/M.体外释药发现NPF/G/M在肿瘤环境(pH=5.5)中的药物释放量为正常生理环境(pH=7.4)中的3倍,表明其具有良好的药物输送特性.此外,利用流式细胞术和MTT毒性测试探究了MCF-7细胞摄取NPF/G/M的机制及动力学特性和细胞毒性,结果表明NPF/G/M以依赖能量、温度、网格蛋白、小窝蛋白和叶酸受体介导的机制进入细胞,从而将药物缓慢释放于细胞内,进而诱导细胞凋亡.研究结果表明, NPF/G/M可作为一种良好的药物输送体系,为其应用于乳腺癌的临床治疗提供理论参考.

We fabricated a targeted nanodiamond drug system(NPF/G/M) through physical adsorption of methotrexate(MTX) using carboxylated nanodiamonds(ND-COOH) modified with polyethylene glycol diamine(H2N-PEG-NH2), folic acid(FA) and glycidol(GLY) as carriers. The preparation of NPF/G/M was verified by morphological observation, energy dispersive spectroscopy(EDS) of the elemental analysis, zeta potential and particle size. The results showed that NPF/G/M can be effectively released in the tumor site, which is three times than in the physiological environment(pH=7.4). Relying on the high affinity between folate and folate receptors, NPF/G/M was uptaken by tumor cells through energy, temperature, clathrin, caveolin-dependent and folate receptor-mediated endocytosis. Interestingly, toxicity tests showed that NPF/G/M can slowly release the drug into the cells and induce cell apoptosis. The above results indicate that NPF/G/M can be used as a good drug delivery system, which will provide a theoretical reference for clinical application in breast cancer.