化学学报 ›› 2013, Vol. 71 ›› Issue (05): 782-786.DOI: 10.6023/A13010148 上一篇    下一篇

研究论文

荧光纳米钻石与转铁蛋白的相互作用及其在细胞内的成像应用

王东新a,b, 李英奇a,c, 杨斌盛a   

  1. a 山西大学分子科学研究所 化学生物学与分子工程教育部重点实验室 太原 030006;
    b 山西医科大学公共卫生学院 太原 030001;
    c 山西大学化学化工学院 太原 030006
  • 收稿日期:2013-01-31 出版日期:2013-05-14 发布日期:2013-03-15
  • 通讯作者: 李英奇,wkyqli@sxu.edu.cn;杨斌盛,yangbs@sxu.edu.cn E-mail:wkyqli@sxu.edu.cn;yangbs@sxu.edu.cn
  • 基金资助:

    项目受国家自然科学基金(No. 21071091)、山西省自然科学基金(No. 2009011012-3)、山西省归国留学基金(No. 201011)和山西医科大学青年基金(No. 02201114)资助.

Interaction between Fluorescent Nanodiamond and Human Transferrin and Intracellular Imaging

Wang Dongxina,b, Li Yingqia,c, Yang Binshenga   

  1. a Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China;
    b Public Health College, Shanxi Medical University, Taiyuan 030001, China;
    c College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China
  • Received:2013-01-31 Online:2013-05-14 Published:2013-03-15
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 21071091), the Shanxi Provincial Natural Science Foundation (Grant No. 2009011012-3), Shanxi Scholarship Council of China (201011) and the Youth Foundation of Shanxi Medical University (02201114).

通过电导返滴定法测定经强酸氧化后的荧光纳米钻石(FND, 约140 nm)表面羧基含量为126 μmol/g, 占表面原子数的29.7%. 对FND物理吸附人转铁蛋白(hTf)进行了研究, 其吸附行为符合Langmuir等温吸附, 在PBS(pH 7.4)中最大吸附量为(176.46±2.13) μg/mg, 同时研究了pH对FND吸附hTf的影响, 发现在pH等于hTf的等电点附近有最大吸附. 利用激光共聚焦和流式细胞仪对FND和FND-hTf内吞到人肝癌细胞(HepG2)的差异进行了定性和定量分析, 结果得到FND-hTf比FND容易内吞到细胞中, 利于胞内成像.

关键词: 荧光纳米钻石, 转铁蛋白, Langmuir等温吸附, 细胞成像

Nanodiamond (ND), as a member of carbon nanomaterials family, has recently received increasing attention for their potential applications as imaging and drug delivery agents. Due to several charming properties, such as surface functionalization capability, biocompatibility and chemical stability, ND demonstrates high affinity to biomolecules. In this work, the adsorptive behavior of oxidized fluorescent nanodiamond (FND, with a size of ca. 140 nm) for hTf was investigated. The amount of surface carboxylic acid on oxidized FND was 126 μmol/g determined by conductometric backward titration. This amount is 29.7% of the total surface atoms. HTf physically adsorbed on the surface of FND (FND-hTf) in PBS (pH7.4) shows that the isothermyal adsorption behavior is coincident with Langmuir model and the maximum adsorbed amount is (176.46±2.13) μg/mg. ND coated human transferrin (hTf) can improve the dispersity and stability compared to pristine FND under a physiological environment or in cell culture medium observed through optical microscope and be more suitable for biomedicine applications. Simultaneously, pH effect on hTf adsorbed onto FND is also inquiried. The result exhibits that FND has the greatest adsorption capacity for hTf close to the isoelectric point. Owing to the negatively charged nitrogen- vacancy (N-V)- defect centers, FND can absorb strongly at ca. 560 nm and emit fluorescence efficiently at ca. 700 nm, which can be well quantitatively and qualitatively analyzed by flow cytometry and confocal fluorescence images. In vitro experiments of human liver cancer cells (HepG2) uptake of nanoparticles display that FND-hTf nanoparticles are more easily endocytosed than that of pristine FND. So FND-hTf is conducive to cell imaging. Furthermore, flow cytometry assay indicates cellular uptake of FND-hTf reached a plateau at about 8 h and the uptake half-life is about (1.41±0.22) h at a particle concentration of 100 μg/mL. The results obtained by confocal fluorescent images display that the FND-hTf nanoparticles locate in the cytoplasm and mainly distribute on the surface of the nucleus, however, can not enter the nucleus.

Key words: fluorescent nanodiamond, human transferrin, Langmuir isothermy adsorption, cell imaging