Fig. 5

In vivo biodistribution. (a) Fluorescence images of 4T1 tumor-bearing mice after intravenous injection of FessMOF-PEG@ICG and ICG. (b) Comparison of fluorescence intensity at tumor sites upon injection of FessMOF-PEG@ICG and ICG. (c) Representative fluorescence images of major organs and tumors after intravenous injection of FessMOF-PEG@ICG and ICG at 24 h (He, Li, Sp, Lu, Ki, Br, and Tu indicate the heart, liver, spleen, lung, kidney, brain, and tumor, respectively). (d) Quantification of fluorescence intensity in tumors and major organs at 24 h. All data were presented as mean ± standard deviation. Statistical differences were calculated using two-tailed Student’s t test. Differences were considered significant when the p-value was less than or equal to 0.05. *** p < 0.001