# Dark-Field Hyperspectral Microscopy for Carbon Nanotubes Bioimaging
## 3 In Vitro Studies of CNTs
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**System** & **Cell Culture** & **Type of CNTs** & **Size of Tested CNTs** & **Treatment Condition** & **Sample Preparation** & **Results** & **Reference** \\ \hline \multirow{8}{*}{CytoViva enhanced dark-field microscopy setup} & PANC-1 cell line & SWCNTs & L 0.3-3.0 \(\mu\)m, D: 0.7-1.6 nm & 10 \(\mu\)g/mL for 1, 4, 8 and 24 h & Living cell samples & Imaging showed time-dependent cellular uptake/accumulation of SWCNTs started at 4 h of exposure & Imaging showed time-dependent cellular uptake/accumulation of SWCNTs started at 4 h of exposure & Imaging showed time-dependent cellular uptake/accumulation of SWCNTs started at 4 h of exposure & Imaging showed time-dependent cellular uptake/accumulation of SWCNTs & Imaging revealed time-dependent accumulation of CNTs & Imaging revealed time-dependent accumulation of CNTs & Imaging revealed time-dependent accumulation of CNTs & Imaging revealed time-dependent accumulation of CNTs & Imaging confirmed both time-dependent membrane and partial intercalation of SWCNTs & Imaging confirmed both time-dependent membrane and partial intercalation of SWCNTs & Imaging confirmed the time-dependent transmission of SWCNTs & Imaging confirmed the time-dependent transmission of SWCNTs & Imaging confirmed the time-dependent transmission of SWCNTs & Imaging of SWCNTs & Imaging of SWCNTs & Imaging performed time-dependent transmission of SWCNTs & Imaging performed time-dependent transmission of SWCNTs & Imaging performed time-dependent transmission of SWCNTs & Imaging confirmed the time-dependent transmission of SWCNTs \begin{table}
\begin{tabular}{p{10.0 pt} p{108.4 pt} p{108.4 pt} p{108.4 pt} p{108.4 pt} p{108.4 pt} p{108.4 pt} p{108.4 pt}} \hline \hline  & & SWCNTs & (L: 1.08 \(\mu\)m, W: 270 nm), MWCNTs & 0.1 \(\mu\)g/mL for 24 & Fixed with NBF and stained with toluidine blue & Imaging showed that both types of CNTs were co-localized in the cytoplasm of cells or puncturing the cellular and nuclear membranes & [72] \\ \cline{3-6}  & & & MWCNT & & & \\ Cytova & & & & & & \\ Cytova & & & & & & \\ enhanced & & & & & & \\ enhanced & & & & & & \\ dark-field & & & & & & \\ microscopy & & & & & & \\ setup & & & & & & \\ \hline \hline \end{tabular}
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Table 1: _Cont._In addition to Rayleigh scattering, CNTs also exhibit Raman spectra that can be used to detect cellular uptake behaviour in combination with dark-field microscopy. The surface-enhanced Raman scattering (SERS) coupled with EDFM was used when investigating the effect of size and aspect ratio parameters of hydroxylated nanotubes on biocompatibility, which attested the intracellular uptake only of \"short and narrow\" (SN) rather than \"long and narrow\" (LN) or \"long and wide\" (LW) CNTs [55]. Besides dark-field microscopy, intercellular carbon nanotube translocations could also be assessed using flow cytometry imaging of single cells on bright-field, dark-field, and fluorescent channels simultaneously [81]. Interestingly, the fluorescence signal of CNTs-loaded cells was less reliable than light absorbance and scattering data obtained from bright-field and dark-field images.