Rational Design of a Tandem Activatable Fluorescent Probe for Differential Diagnosis and Therapeutic Assessment of Hepatocellular Carcinoma

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