A successful drug delivery device for cancer chemotherapy should ideally be able to load drugs highly, bring the drug preferentially into tumor cells and reduce its distribution in normal tissue to enhance therapeutic efficacy. To this purpose, a novel protocol for DOX-loaded PEGylated nanodiamond (ND-PEG-DOX/NaAc, NPDA) was fabricated using sodium acetate medium. The NPDA nanoparticles exhibited a maximum loading efficiency (99 wt%) with ultra-low drug leakage (7 wt%). Examination by confocal microscope and flow cytometer showed that the NPDA uptake by cells was time-dependent, with a slow and sustained drug release from the lysosomes at a low pH. Also, when CHO (a normal cell) and MCF-7 (a cancer cell) were treated with NPDA, the results demonstrated that NPDA preferentially accumulated much more in tumor cells than in normal cells, which implied that NPDA has the ability to selectively kill tumor cells. In addition, NPDA can inhibit the migration and proliferation of tumor cells and change the cell cycle compared to the free drug. Outcomes from this work suggest that NPDA would be a promising drug delivery platform and the preparation of such a drug delivery system will also have implications in improving the biomedical applications of smart nanodiamond carriers.

中文翻译：

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乙酸根离子增强了阿霉素在聚乙二醇化纳米金刚石上的负载和稳定性，可用于选择性肿瘤细胞内控释和治疗。

一个成功的用于癌症化疗的药物输送装置理想上应该能够高载药，将药物优先带入肿瘤细胞并减少其在正常组织中的分布以增强治疗效果。为了这个目的，使用乙酸钠介质制备了用于DOX负载的PEG化纳米金刚石的新方案（ND-PEG-DOX / NaAc，NPDA）。NPDA纳米颗粒具有最大的装载效率（99重量％）和超低的药物泄漏（7重量％）。共聚焦显微镜和流式细胞仪检查表明，细胞对NPDA的吸收是时间依赖性的，在低pH值下从溶酶体中缓慢而持续地释放药物。同样，当用NPDA处理CHO（正常细胞）和MCF-7（癌细胞）时，结果表明NPDA在肿瘤细胞中的优先积累要比正常细胞中的多，这暗示NPDA具有选择性杀死肿瘤细胞的能力。此外，与游离药物相比，NPDA可以抑制肿瘤细胞的迁移和增殖并改变细胞周期。这项工作的结果表明，NPDA将是一个有前途的药物输送平台，而这种药物输送系统的制备也将对改善智能纳米金刚石载体的生物医学应用产生影响。