OTN-NIR Fluorescent Single-Walled Carbon Nanotubes in Murine Colon-26 Cells

Hypothesis: o-SWCNTs may be suitable for cellular labeling with OTN-NIR fluorescence. The data shows that OTN-NIR fluorescence was not observed in the cells after 24-h incubation with the o-SWCNT-PEG but clearly increased with longer incubation time from three days after the treatment (Figure 4). This result was further confirmed by Raman microscopy (Figure 5). OTN-NIR fluorescence intensity was associated with the cellular uptake of the o-SWCNT-PEG. These results suggest that the Colon-26 cells were successfully labeled by the o-SWCNTs-PEG that emit OTN-NIR fluorescence. This delayed concentration followed by a long retention of the o-SWCNT-PEG in cells will facilitate further biotechnological applications of the o-SWCNTs to in vivo deep OTN-NIR fluorescent imaging. These data were gathered using the o-SWCNTs were synthesized by oxygenation of SWCNTs by ozone under ultraviolet irradiation and were dispersed in an aqueous solution of DSPE-PEG to prepare biocompatible o-SWCNTs (o-SWCNT-PEG).

假说：氧化单壁碳纳米管（o-SWCNTs）或可适用于搭载OTN-NIR荧光的细胞标记实验。实验数据显示，经o-SWCNT-PEG孵育24小时后，细胞中未观测到OTN-NIR荧光信号；但在处理后第3天起，随着孵育时间延长，荧光信号显著增强（图4）。拉曼显微成像进一步验证了这一结果（图5）。OTN-NIR荧光强度与o-SWCNT-PEG的细胞摄取量密切相关。上述结果表明，发射OTN-NIR荧光的o-SWCNTs-PEG已成功实现对Colon-26细胞的标记。o-SWCNT-PEG在细胞内先经历摄取延迟、随后长期驻留的特性，将推动氧化单壁碳纳米管在体内深层OTN-NIR荧光成像领域的进一步生物技术应用。本研究所用的o-SWCNTs通过臭氧在紫外辐照下对单壁碳纳米管（SWCNTs）进行氧化合成，并经DSPE-PEG水溶液分散以制备生物相容性的o-SWCNT-PEG。