Fig. 4

In vivo biodistribution of RL-NP loading DiD in the SCC7 allograft model (n = 3). a Whole body images of SCC7 tumor-bearing mice after intravenous injection of free DiD, RL-NP-DiD, and NP-DiD. Black dotted circles are tumor regions. b Near-infrared (NIR) fluorescence intensity in tumor area from a. c Fluorescence images of blood samples from mice. d NIR fluorescence intensity in blood from c. e Ex vivo NIR fluorescence images of tumors and major organs. f NIR fluorescence intensity in tumors and major organs in e (****p < 0.0001). g Fluorescence images of cryo-sectioned tumor tissues