Fig. 4

A The in vivo biodistribution of IR-780 and IR-780@MPDA at different time points (0, 2, 4, 6, 8, and 12 h) after i.v. injection. B The fluorescence intensities of tumors at different time points after i.v. injection of IR-780 or IR-780@MPDA. Asterisk * indicated p < 0.05. C PA imaging in vivo at 0, 2, 4, 6, 8, and 12 h by using indicated contrast agents. D The relative PA intensities of tumors at different time points after i.v. injection of IR-780, MPDA or IR-780@MPDA