Figure 6.

In vivo cell tracking and active tumor targeting with LGO:Cr nanoparticles. (A-C) Tracking the migration of PEI-LGO:Cr nanoparticles-labeled RAW264.7 cells in subcutaneous 4T1 tumor model. The PEI-LGO:Cr nanoparticles were UV pre-irradiated by a 254 nm UV lamp for 15 min, and then loaded into RAW264.7 cells for a 48 h incubation. The labeled RAW264.7 cells (~1.0×10⁶ cells) were intravenously injected. Whole body luminescence images were acquired before and after illuminating the mouse by a white LED flashlight (for 15 s) at (A) 30 min, (B) 24 h, and (C) 72 h after the cell injection. (D,E) Active tumor targeting with c(RGDyK)-conjugated LGO:Cr nanoparticles in subcutaneous 4T1 tumor model. The c(RGDyK)-LGO:Cr nanoparticles were irradiated by a 254 nm UV lamp for 15 min before the intravenous injection. Luminescence images were acquired before and after illuminating the mouse by a LED flashlight (for 15 s) at (D) 6 h and (E) 24 h after the cell injection. The tumor sites are indicated by pink circles. All images were acquired on an IVIS imaging system in the bioluminescence mode with an exposure time of 3 min.