An Activatable Fluorescence/Photoacoustic Bimodal Probe for the Detection of Drug-Induced Liver Senescence

Senescence is an intricate physiological progression that can be instigated by a multiplicity of factors. Aberrant cellular senescence is capable of precipitating a substantial array of diseases. During chemotherapy, drugs typically tend to gradually accumulate in the liver, thereby inducing liver senescence and leading to a successive deterioration in its physiological function. β-galactosidase (β-gal), serving as a significant index in the exploration of senescence, has attracted considerable attention. In this study, a fluorescence/photoacoustic (FL/PA) biomodal probe (Gal-QCS) was developed based on a hemicyanine fluorophore for the imaging of β-gal in the process of drug-induced liver senescence. Gal-QCS demonstrates rapid responsiveness, high sensitivity, and remarkable selectivity in detecting β-gal in aqueous solutions. After incubation with β-gal, the fluorescence signal at 810 nm significantly increases, and concurrently, the photoacoustic signal at 775 nm also exhibits a substantial increment. Upon the induction of cell senescence with camptothecin, Gal-QCS can expeditiously and selectively image senescent cells. Moreover, after administering this probe to mice with liver senescence, the FL/PA signals in the livers of senescent mice were enhanced by 10.53-fold and 1.43-fold, respectively. This work robustly substantiates the potential and application prospects of Gal-QCS in detecting drug-induced liver senescence, with β-gal serving as a biomarker.