### 基于碳点多功能纳米载药体系的制备及pH响应释药性能研究

1. 华南理工大学发光材料与器件国家重点实验室 华南理工大学材料科学与工程学院 广州 510640
• 投稿日期:2015-12-15 发布日期:2016-02-23
• 通讯作者: 杜方凯, 吴水珠 E-mail:dufangkai501@163.com;shzhwu@scut.edu.cn
• 基金资助:

项目受国家自然科学基金(Nos. 21474031, 21174040, 21025415)、中国博士后科学基金(No. 2015M572305)和国家重大科学研究计划(No. 2013CB834702)资助.

### Preparation of a Multifunctional Nano-carrier System Based on Carbon Dots with pH-Triggered Drug Release

Du Fangkai, Xu Jiangsheng, Zeng Fang, Wu Shuizhu

1. College of Materials Science and Engineering, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640
• Received:2015-12-15 Published:2016-02-23
• Supported by:

Project supported by the NSFC (Nos. 21474031, 21174040, 21025415), China Postdoctoral Science Foundation (No. 2015M572305) and the National Key Basic Research Program of China (Project No. 2013CB834702).

A folated-functionalized nano-carrier system based on carbon dots was successfully synthesized for cancer cell-targeted drug delivery. In this report, using microwave-assisted assay the fluorescent CDots could be obtained via microwave-assisted pyrolysis of glycerol in the presence of 4,7,10-trioxa-1,13-tridecanediamine. The particle size of the CDots was confirmed by AFM and HR-TEM. The finding showed that the average diameter of CDots is about 4 nm. Incorporating (via a cleavable bond) an anticancer drug, which was Doxorubicin (DOX) in this study, and a targeting ligand (folic acid) onto carbon dot produces a more specific anticancer prodrug DOX-CDots-FA. The structure of the DOX-CDots-FA was characterized by 1H NMR and UV-vis analysis. The loading content of DOX was determined by UV-vis analysis to be 13.5 wt%, and the content of the targeting ligand FA was calculated as 3.13 wt% based on 1H NMR measurement. Particle size parameter of DOX-CDots-FA was determined by HR-TEM. The results showed that the average diameter of DOX-CDots-FA is about 6 nm. In addition, DOX-CDots-FA showed pH-dependent release, that is, the drug releases faster in pH=5.2 buffer solution than in pH=7.4 one. The cytotoxicity of DOX-CDots-FA, DOX-CDots nanoparticles and free DOX were evaluated and compared using HeLa and L929 cell lines. For the FR-positive HeLa cells, DOX-CDots-FA nanoparticles exhibit superior cytotoxicity as compared to DOX-CDots nanoparticles. These results showed that the FA moieties in DOX-CDots-FA nanoparticles play an important role in enhancing the cytotoxic effect as they increase the binding to FR-expressing cells. This high affinity binding subsequently increases their intracellular uptake as a result of receptor-mediated endocytosis. The FA molecules present on the surface of the nanoparticle prodrug do not have a remarkable effect on cellular uptake and/or cytotoxicity for FR-negative L929 cell lines. The confocal microscope studies revealed that FA-conjugated prodrug DOX-CDots-FA exhibited higher cellular uptake than FA-free nanosystem DOX-CDots which also led to higher cytotoxicity. Thus, multifunctional nano-carrier system could be a promising nanosize anticancer drug carrier with excellent targeting property.