Activatable Phototheranostic Materials for Imaging-Guided Cancer Therapy.

Cancer theranostics, which combines diagnostic and therapeutic effects into one entity, holds promise in precision medicine. Conventional theranostic agents possess always-on imaging signals and cytotoxic effects and thus often encounter poor selectivity or specificity in cancer treatment. To tackle this issue, activatable phototheranostic materials (PMs) have been developed to simultaneously and specifically turn on their diagnostic signals (fluorescence/self-luminescence/photoacoustic signals) and photothermal/photodynamic effects in response to cancer hallmarks. This Review summarizes the recent progress in the design, synthesis and proof-of-concept applications of activatable PMs. The molecular engineering strategy to increase tumor accumulation and enhance treatment efficacy are highlighted. Current challenges and future perspectives in this emerging field are also discussed.