Fig. 4

An activated excretion-retarded tumor imaging (AERTI) strategy was reported. In vivo verification of the tumor-selectively accumulation, retention and the SNR in tumor imaging of AERTI strategy. A Schematic illustration of the AERTI strategy. The AERTI strategy consisted of RGD, PLGYLG, KLVFFGC, Cy and SSGG. Upon MMP-2 specific enzymatic cleavage, the remaining molecule was triggered to form nanofibril conformation of antiparallel β-sheet. B Representative fluorescence images of 786-O xenograft mice after intravenous injection of M1, M2 and ICG. C Representative fluorescence images of RCC after intravenous administration in the orthotopic RCC xenograft mice at 24 h post injection. Calculate and statistical analyses SNR ratio. The tumor boundary identified by naked eyes, fluorescence imaging, H&E and fluorescence microscopy imaging results. Figure adapted from Da-Yong Hou et al. [89]