Ultrastructure of a Carbon Nanotube-based Delivery Syste

我们进行了超微结构实验，以研究功能化碳纳米管在口腔癌细胞中的应用。抗癌药物顺铂被共价结合到单壁碳纳米管(SWNTs)上，这些单壁碳纳米管又与口腔癌细胞高水平表达的表皮生长因子(EGF)结合。将功能化纳米颗粒与上皮源性HNSCC细胞孵育后，用戊二醛和四氧化三铯固定，脱水，包埋在EPON中，制备电子显微镜。使用120千伏电子显微镜数字化记录的电子显微镜显示，成束的单壁碳纳米管已经进入细胞。在大多数细胞中，单壁碳纳米管束分布在细胞质中，而一些细胞在靠近细胞核的地方显示出较高浓度的纳米管。结果证实了从共聚焦荧光显微镜获得的较低分辨率的数据，但提供了关于进入纳米管后与亚细胞结构相关的更详细的信息。还进行了扫描电子显微镜(STEM)和X射线纳米分析，以表征单个纳米管并确定结合铂原子的分布。

We have performed ultrastructural experiments to investigate the application of functionalized carbon nanotubes to deliver therapeutic drugs to oral cancer cells. The anti-cancer drug cisplatin was covalently bound to single walled carbon nanotubes (SWNTs) and these were in turn bound to epidermal growth factor (EGF), which is expressed at very high levels by oral cancer cells. Cultured HNSCC cells of epithelial origin incubated with the functionalized nanoparticles were prepared for electron microscopy by fixation in glutaraldehyde and osmium tetroxide, followed by dehydration and embedding in epon. Electron micrographs, recorded digitally using a 120 kV TEM, revealed that bundles of SWNTs had entered the cells. In most cells the SWNT bundles were distributed throughout the cytoplasm, whereas some cells showed a higher concentration of nanotubes adjacent to the cell nucleus. The results confirmed lower resolution data obtained from confocal fluorescence microscopy but provided more detailed information about the subcellular structures associated with the nanotubes after entry. Scanning transmission electron microscopy (STEM) and x-ray nanoanalysis are also being performed to characterize individual nanotubes and to determine the distribution of bound platinum atoms.