Madani Seyed Yazdan, Tan Aaron, Naderi Naghmeh, Seifalian Alexander M
UCL Centre for Nanotechnology and Regenerative Medicine, University College London, London NW3 2PF, UK.
J Nanosci Nanotechnol. 2012 Dec;12(12):9018-28. doi: 10.1166/jnn.2012.6746.
Single walled carbon nanotubes (SWCNTs) have distinctive physical and chemical properties. Additionally, innovative properties can be established to match the clinical need by attachment of functional groups to the SWCNT. In this experiment SWCNT was functionalized with OctaAmmonium-POSS. Evidence suggests that functionalization of SWCNT with OctaAmmonium-POSS would augment the dispersion of SWCNT. We further postulate that functionalization of SWCNT with OctaAmmonium-POSS would enhance the temperature increase of SWCNT upon exposure to NIR laser irradiation.
Functionalization of SWCNT was conferred by refluxing with acid and OctaAmmonium-POSS. Fourier Transform Infrared (FTIR) test UV-visible spectroscopy and morphology analysis using Transmission Electron Microscopy (TEM) confirmed successful functionalization of SWCNT. NIR irradiation of samples was conducted using an 808 nm laser at 1 watt. Temperature changes were documented using a thermal camera. A HT-29 colorectal cancer cell line was used as a model for photothermal ablation. Cell viability test was performed using trypan blue and fluorescence activated cell sorting (FACS) technique. Graph plotting and statistical analysis was conducted using Graph Pad Prism.
Following the functionalization process, TEM images showed a layer on the surface of the SWCNT. In the FTIR experiment, results illustrated the presence of the -COOH group on the functionalized SWCNTs. Upon further functionalization of SWCNT with OctaAmmonium-POSS, various peaks determined the formation of amide bond between the POSS molecule and functionalized SWCNT. The UV-visible spectra also determine the successful functionalization of the SWCNT following its treatment with acid and OctaAmmonium-POSS. Upon exposure to NIR, OctaAmmonium-POSS-SWCNT was the only treatment group that illustrated significantly higher temperature increase than the other treatment groups. Additionally cell death of NIR irradiated OctaAmmonium-POSS-SWCNT was statistically significant compared to other treatment groups.
OctaAmmonium-POSS was used to render SWCNT biocompatible and water dispersible. Observation from this study determines that functionalization with OctaAmmonium-POSS show greater temperature increase compared to pristine SWCNTs upon its exposure NIR. This significant temperature increase is due to increasing the solubility of SWCNT following its functionalization with OctaAmmonium-POSS.
单壁碳纳米管（SWCNTs）具有独特的物理和化学性质。此外，通过将官能团连接到SWCNT上，可以赋予其创新性质以满足临床需求。在本实验中，SWCNT用八铵基倍半硅氧烷（OctaAmmonium-POSS）进行了功能化处理。有证据表明，用OctaAmmonium-POSS对SWCNT进行功能化处理会增强SWCNT的分散性。我们进一步推测，用OctaAmmonium-POSS对SWCNT进行功能化处理会增强SWCNT在近红外激光照射下的升温效果。
通过用酸和OctaAmmonium-POSS回流对SWCNT进行功能化处理。傅里叶变换红外光谱（FTIR）测试、紫外可见光谱以及使用透射电子显微镜（TEM）进行的形态分析证实了SWCNT功能化处理的成功。使用1瓦的808纳米激光对样品进行近红外照射。使用热成像仪记录温度变化。使用HT-29结肠癌细胞系作为光热消融模型。使用台盼蓝和荧光激活细胞分选（FACS）技术进行细胞活力测试。使用Graph Pad Prism进行绘图和统计分析。
经过功能化处理后，TEM图像显示SWCNT表面有一层物质。在FTIR实验中，结果表明功能化的SWCNT上存在-COOH基团。在用OctaAmmonium-POSS对SWCNT进一步功能化处理后，各种峰表明在POSS分子与功能化的SWCNT之间形成了酰胺键。紫外可见光谱也确定了SWCNT在用酸和OctaAmmonium-POSS处理后功能化处理的成功。在近红外照射下，OctaAmmonium-POSS-SWCNT是唯一显示出比其他处理组显著更高升温的处理组。此外，与其他处理组相比，近红外照射的OctaAmmonium-POSS-SWCNT导致的细胞死亡具有统计学意义。
OctaAmmonium-POSS用于使SWCNT具有生物相容性和水分散性。本研究的观察结果表明，与原始SWCNT相比，用OctaAmmonium-POSS进行功能化处理后在近红外照射下升温更大。这种显著的升温是由于用OctaAmmonium-POSS对SWCNT进行功能化处理后其溶解度增加所致。
