Activatable nanoscale metal-organic framework for ratiometric photoacoustic imaging of hydrogen sulfide and orthotopic colorectal cancer in vivo

Nanoscale metal-organic frameworks(nano MOFs)have emerged as a promising biomedical nanoplatform because of their unique properties.However,the exploration of nano MOFs in photoacoustic(PA)imaging is still limited.Here,a novel hydrogen sulfide(H2 S)-activated nano copper-based MOF(Cu-MOF)was developed as a near-infrared(NIR)ratiometric PA probe for in vivo monitoring of endogenous H2 S level and orthotopic colorectal cancer imaging via in situ reaction of nano Cu-MOFs with endogenous H2 S that is closely associated with tumor growth and proliferation in colon cancer.The synthesized nano Cu-MOFs displayed excellent PA responsiveness towards tumor H2 S level with high selectivity and rapid kinetics.The result suggests the developed probe may provide a unique opportunity to investigate the malignant behaviors of H2 S-associated events in vivo.