Novel PET Imaging Probe for Quantitative Detection of Senescence In Vivo

Real-time detection of cellular senescence remains a
clinical challenge.
Here, we aimed to develop a positron emission tomography (PET) imaging
probe targeting senescence-associated β-galactosidase (SA-β-Gal),
the most widely used biomarker of cellular senescence, and investigate
its performance for real-time in vivo quantitative detection of cellular
senescence. A stable PET imaging agent [68Ga]­Ga-BGal was obtained with a high labeling yield
(90.0 ± 4.3%) and a radiochemical purity (>95%). [68Ga]­Ga-BGal displayed high
sensitivity and specificity for β-Gal both in vitro and in vivo.
The reaction and uptake of the probe correlated with the β-Gal
concentration and reaction time. In PET imaging, high β-Gal-expressing
CT26.CL25 tumors and doxorubicin-treated HeLa tumors showed high signals
from [68Ga]­Ga-BGal, while a low signal was observed in CT26.WT and untreated HeLa tumors.
In summary, we showcased successful PET imaging of senescence in preclinical
models using probe [68Ga]­Ga-BGal. This finding holds the potential for translating senescence imaging
into clinical applications.