Figure 16.

a) Reaction of QC under MMP-2 catalysis. b) PA images of 4T1 tumors of different sizes after injection of QC or control probe under 680 nm or 730 nm laser irradiation. c) Reaction of AlNc-pep-PEG under MMP-2 catalysis. d) PA images (with and without merged background) of the HT-1080 fibrosarcoma tumor before and after injection of AlNc-pep-PEG or AlNc-PEG under 680 nm or 760 nm laser irradiation. e) Schematic of the synthesis and reaction of PEG-pep-Dox-AuNPs under MMP-2 catalysis. f) PA images (with and without merged US signal) in SCC-7 tumor-bearing mice before and at various time points after injection of EG-Dox-AuNPs or EG-pep-Dox-AuNPs. g) Reaction of AuNS-1 and AuNS-2 with MMP-9. h) 3D PA image in a breast cancer mouse model at 24 hours after injection of saline, control probe and MMP-9 probe. Yellow: skin and surface vasculature; red: aggregated nanoparticles; light blue dashed line: tumor boundary. i) Reaction of P-Dex under uPA catalysis. j) PA images of the MDA-MB-231 tumor (with or without pre-treatment of 4-CPG) or MCF-7 tumor before and at various time after injection of P-Dex or SP. a) and b) are reproduced from ref. 193 with permission from American Chemical Society, Copyright 2019. c) and d) are reproduced from ref. 195 with with permission from American Chemical Society, Copyright 2021. e) and f) are reproduced from ref. 191 with permission from Elsevier, Copyright 2019. g) and h) are reproduced from ref. 196, which is an open-access article distributed under the Creative Commons License, 2021 Elsevier. i) and j) are reproduced from ref. 199 with permission from John Wiley and Sons, Copyright 2020.