中文摘要：

通过共价键合方法 将叶酸配体和化疗药物甲氨蝶呤偶联于PEG化的纳米钻石载体上,获得纳米钻石-PEG-叶酸/甲氨蝶呤（ND-PEG-FA/GLY-MTX,NPFGM）药物输送体系。采用紫外-可见吸收光谱法测定了纳米钻石表面偶联甲氨蝶呤的量为（123±5.8）μg/mg。通过体外释药研究,表明NPFGM纳米颗粒在生理条件下具有良好的稳定性,而在微酸性溶菌酶存在下,酯键水解断裂导致药物甲氨蝶呤被催化释放。以乳腺癌细胞为模型,采用流式细胞技术表明细胞摄取纳米钻石药物体系主要通过小窝蛋白-决定、叶酸受体介导的靶向机制进入细胞。这些研究结果表明NPFGM是一个很有前途的药物递送平台,并为共价偶联药物提供新思路。

英文摘要：

Due to the high biocompatibility and the surface easily modified, nanodiamond has been widely used in drug carriers. The folic acid and chemotherapeutic drug methotrexate were coupled to PEGylated nano-diamond carrier to obtain nanodiamond-PEG-folic acid/methotrexate （ND-PEG-FA/GLY-MTX, NPFGM） drug delivery system through covalent bonding method. The amounts of methotrexate were （123±5.8）μg/mg by UV-Vis spectrophotometry, respectively. The results showed that NPFGM nanoparti- cles had good stability under physiological conditions, and in the presence of slightly acidic lysozyme, the hydrolysis of ester bonds resulted in the release of methotrexate. Using breast cancer cells as a model, flow cytometry was used to show that cellular uptake of the NPFGM system mainly through caveolin-de- pendent and folate receptor-mediated targeting mechanisms into cells. These results suggest that NPFGM is a promising drug delivery platform and provides new ideas for covalent conjugated drugs.