Rational Design of a Tandem Activatable Fluorescent\nProbe for Differential Diagnosis and Therapeutic Assessment of Hepatocellular\nCarcinoma

Hepatocellular\ncarcinoma (HCC) is a formidable disease, distinguished\nby its high aggressiveness and dismal outcomes. Although leucine aminopeptidase\n(LAP) has been widely employed as a biomarker in biological imaging\nof HCC, it is still susceptible to interference from false-positive\nsignals activated in injured liver tissues. In this study, based on\nthe significant difference of GSH levels in alcohol-damaged liver\ntissues and tumor tissues, a dual-tandem activatable probe (PCLT)\nwas designed for differential diagnosis and treatment guidance of\nHCC by near-infrared fluorescence (NIRF) imaging. This probe comprised\na dual-locked hemicyanine dye decorated with a tetraethylene glycol\nchain and dual-recognition unit of glutathione (GSH) and LAP, which\ncould be sequentially cleaved by GSH and LAP to restore its NIRF signal.\nPCLT excellently discriminated orthotopic HCC from ALI far earlier\n(7 days) than histological analysis (28 days) and exhibited higher\nspecificity toward early orthotopic HCC than the single-locked probe\n(PCL). In addition, PCLT is capable of accurately delineating the\ntumor contour, assisting in surgical resection of HCC tumors under\nfluorescence visualization, and noninvasively assessing the antitumor\neffect of HCC chemotherapy during ferroptosis, thereby presenting\npromising clinical implications for clinical diagnosis and therapy\nof HCC.