Cai_2020_Angew.Chem.Int.Ed.Engl__

Photodynamic therapy (PDT) exhibits great potential for cancer therapy, but still suffers from nonspecific photosensitivity and poor penetration of photosensitizer. Here, a smart perylene monoimide-based nanocluster with enzyme-triggered disassembly is reported as an activatable and deeply penetrable photosensitizer. A novel carboxylesterase (CE)-responsive tetrachloroperylene monoimide (P1) was synthesized and assembled with folate-decorated albumins into a nanocluster ( FHP ) with a diameter of ~100 nm. Once P1 is hydrolyzed by the tumor-specific CE, FHP disassembles into ultrasmall nanoparticles (~10 nm), facilitating the deep tumor penetration of FHP . Furthermore, such enzyme-triggered disassembly of FHP leads to enhanced fluorescence intensity (~8-fold) and elevated singlet oxygen generation ability (~4-fold), enabling in situ near-infrared fluorescence imaging and promoted PDT. FHP permits remarkable tumor inhibition in vivo with minimal side effects through imaging-guided, activatable, and deep PDT. This work confirms that this cascaded multifunctional control via enzyme-triggered molecular disassembly is an effective strategy for precise cancer theranostics.