Fig. 6

a FL images of mice bearing MDA-MB-231 tumors after intravenous injection of free ICG, Lipo/ICG, and Lipo/pB-DOX/ICG at 2, 6, 12, 24, 36, and 48 h. b Ex vivo FL images of major organs and tumors dissected from mice 48 h post injection of different treatment groups. c Semiquantitative biodistribution of free ICG, Lipo/ICG, and Lipo/pB-DOX/ICG in mice determined by the averaged FL intensities of organs and tumor. d PA images of tumor sites on MDA-MB-231-tumor-bearing mice post injection of free ICG, Lipo/ICG, and Lipo/pB-DOX/ICG at 2, 6, 12, 24, and 36 h. e The corresponding PA signals at the tumor sites of MDA-MB-231-tumor-bearing mice post injection of free ICG, Lipo/ICG, and Lipo/pB-DOX/ICG at different time points. (The data are shown as mean ± SD, n = 3 per group, NS, no significance, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001)