Tsai Shiao-Wen, Liaw Jiunn-Woei, Hsu Fu-Yin, Chen Yi-Yun, Lyu Mei-Jhih, Yeh Ming-His
Institute of Biochemical and Biomedical Engineering, Chang Gung University 259 Wen-Hwa 1st Rd., Kwei-Shan, Tao-Yuan, 333, Taiwan.
Department of Mechanical Engineering, Chang Gung University, 259 Wen-Hwa 1st Rd., Kwei- Shan, Tao-Yuan, 333, Taiwan.
Sensors (Basel). 2008 Oct 24;8(10):6660-6673. doi: 10.3390/s8106660.
In this study, we demonstrate that the uptake rate of the surface-modified gold nanoparticles (GNPs) with folic acid by specific cells can be increased significantly, if the membranes of these cells have sufficient folic-acid receptors. Two human breast cancer cell lines were studied; one is MDA-MB-435S cell, and the other T-47D cell. The expression of the folic acid receptors of the former is much higher than that of the latter. These cells were incubated with media containing bare GNPs or GNPs conjugated with folic acid individually. Due to the unique optical behavior (i.e. surface plasmon resonance) of GNPs, the uptake amount of GNPs by cells can be identified by using the laser scanning confocal microscopy. Our experiments show that the uptake amount of GNPs in MDAMB-435S cells is higher than that in T-47D cells for the same culture time, if the culture medium contains bare GNPs. Moreover, if the GNPs conjugated with folic acid are used for the culture, the uptake rate of GNPs by MDA-MB-435S cells is improved more. In contrast, the uptake rates of both GNPs are almost the same by T-47D cells. The phenomenon indicates that the uptake rate of GNPs can be improved via the ligand-receptor endocytosis, compared with the nonspecific endocytosis. Therefore, the uptake rate of GNPs conjugated with folic acid by MDA-MB-435S cells is higher than that of bare GNPs.
在本研究中，我们证明，如果特定细胞的膜上有足够的叶酸受体，那么用叶酸对表面修饰的金纳米颗粒（GNP）的摄取率可显著提高。我们研究了两种人乳腺癌细胞系；一种是MDA-MB-435S细胞，另一种是T-47D细胞。前者的叶酸受体表达远高于后者。将这些细胞分别与含有裸GNP或与叶酸偶联的GNP的培养基一起孵育。由于GNP具有独特的光学行为（即表面等离子体共振），因此可以使用激光扫描共聚焦显微镜来识别细胞对GNP的摄取量。我们的实验表明，在相同培养时间下，如果培养基中含有裸GNP，MDA-MB-435S细胞对GNP的摄取量高于T-47D细胞。此外，如果使用与叶酸偶联的GNP进行培养，MDA-MB-435S细胞对GNP的摄取率提高得更多。相比之下，T-47D细胞对两种GNP的摄取率几乎相同。该现象表明，与非特异性内吞作用相比，通过配体-受体内吞作用可提高GNP的摄取率。因此，MDA-MB-435S细胞对与叶酸偶联的GNP的摄取率高于裸GNP。
