Expanding Anti-Stokes Shifting in Triplet–Triplet Annihilation Upconversion for In Vivo Anticancer-Prodrug Activation

摘要

A strategy to expand anti-Stokes shifting from the far-red to deep-blue region in metal-free triplet–triplet annihilation upconversion (TTA-UC) is presented and its utility in the in vivo titration of the photorelease of an anticancer prodrug is demonstrated. This new TTA system has robust brightness and the longest anti-Stokes shift of any reported TTA system. TTA core-shell-structured prodrug delivery capsules that benefit from these properties are developed; they can operate with low-power-density far-red light-emitting diode (LED) light. These capsules contain mesoporous silica nanoparticles preloaded with TTA molecules as the core and amphiphilic polymers encapsulating anticancer prodrug molecules as the shell. When stimulated by far-red light, the intense TTA upconversion blue emssison in the system activates the anticancer prodrug molecules and shows effective tumor growth inhibition in vivo. This work paves the way for the design of new organic TTA upconversion with regard to in vivo photocontrollable drug release and other biophotonic applications.