Cancer Nanotheranostics - Cancer Nanotheranostics - page 35

Fig. 18 Confocal microscopy images of E. coli ATCC 25922 cells labeled with the C-dots: a
ʻ EX = 458 nm, detected with 475 nm long pass filter; b ʻ EX = 477 nm, detected with 505 nm
long pass filter; c ʻ EX = 488 nm, detected with 530 long pass filter; and d ʻ EX = 514 nm,
detected with 560 nm long pass filter. Adapted from Sun et al., with permission from American
Chemical Society. Copyright 2006
of the available reports on cell imaging applications, suggest that C-dots are mostly
localized in the cytoplasm. However, there have been very few reports on nuclear
uptake of C-dots. In one such report, cellular localization of C-dots within the
nucleus was observed. The internalized C-dots were further able to selectively stain
the nucleoli, thereby achieving organelle selection. The difference of fluorescence
emission between the cytoplasm and nucleus was clearly visible, suggesting the
nuclear uptake (Kong et al. 2014). C-dots have also been used for targeting and
detecting cancer cells. Lee et al. developed an aptamer-conjugated imaging probe
for targeting cancers. Thiol-terminated C-dots (SH-gC-dots) were conjugated
with maleimide-terminated TTA1 aptamer targeting Tnc proteins (TTA1-C-dots).
In order to evaluate the ability of TTA1-C-dots for cancer targeting, cancer cell