“Theranostics” is a combination of diagnostics and therapy in medicine. It can be useful, e.g., in cancer treatment. Most theranostic prodrugs reported to date rely on the release of the active chemotherapeutic agent accompanied with a fluorescence signal. Chemiluminescence, however, would be more sensitive than fluorescence because of its high signal-to-noise ratio.

Doron Shabat, Tel Aviv University, Israel, and colleagues have developed a theranostic prodrug with a chemiluminescence effect. As a model system, the team prepared a prodrug (pictured) from the chemotherapeutic agent monomethyl auristatin E, which is designed for activation by β‐galactosidase. The activation of the prodrug in the presence of β‐galactosidase was accompanied by the emission of a photon in the green region of the spectrum.

The prodrug could be used to selectively image cells that overexpress (i.e., produce a lot of) β-galactosidase in culture. The light intensities observed with increased concentrations of the prodrug were linearly correlated with decreased cell viability. Sharp chemiluminescence images of enzymatic activity in mice with β-galactosidase-overexpressing tumors could also be produced.

• Real-Time Monitoring of Prodrug Activation by Direct-Mode of Chemiluminescence,
  Doron Shabat, Samer Gnaim, Anna Scomparin, Sayantan Das, Ronit Satchi-Fainaro,
  Angew. Chem. Int. Ed. 2018.
  https://doi.org/10.1002/anie.201804816