Figure 3

Activatable aptamer probe (AAP) for in vivo cancer tracking. A) Schematic showing the mechanism of AAP recognition against CCRF-CEM cells. Upon specific binding, the Sgc8 aptamer-containing AAP exhibited conformation alteration, which resulted in fluorescent restoration. B) Flow cytometry data shows the specificity of AAP binding towards CCRF-CEM cells. As comparison, the signal from control probes with no affinity was shown. C) Specific in vivo CCRF-CEM tumor imaging with AAP. One hour following their intravenous injection, AAP accumulated pre-dominantly on CCRF-CEM tumor sites (labeled with pink circle), but not to control Ramos tumors. D) Longitudinal imaging of CCRF-CEM tumor with AAP revealed clear tumor signal between 5 to 120 minutes post-intravenous injection. In comparison, control and “always-on” probe did not show specific fluorescent signal at tumor site. Adapted with permission from ref. [55]. Shi H, He X, Wang K, Wu X, Ye X, Guo Q, Tan W, Qing Z, Yang X, Zhou B: Activatable aptamer probe for contrast-enhanced in vivo cancer imaging based on cell membrane protein-triggered conformation alteration. Proceedings of the National Academy of Sciences 2011, 108:3900–3905. Copyright 2011 by National Academy of Sciences, USA.