Phthalocyanine-Based Nanoassembly with Switchable Fluorescence and Photoactivities for Tumor Imaging and Phototherapy

Switchable theranostics are of great interest for accurate tumor imaging and targeted therapy. Here, we develop smart engineering to construct nanostructured phthalocyanines self-assembled by amphiphilic zinc phthalocyanines (ZnPcs) and hydrophobic copper phthalocyanines (CuPcs) (ZnPc(PEG)5:CuPc-N, where ZnPc(PEG)5 is monosubstituted ZnPcs with pentaethylene glycol as the substituent). The fluorescence and reactive oxygen species generation of ZnPc(PEG)5:CuPc-N can be triggered depending on the membrane of the tumor cells for the imaging and photoactivities. Concerning the stability in blood circulation, the surface of the nanocomplex is coated with polydopamine, which responds to the tumor acidic microenvironment. ZnPc(PEG)5 and CuPc focus on photodynamic and photothermal properties, respectively, and can be stimulated by a single laser beam, endowing ZnPc(PEG)5:CuPc-N a combined antitumor effect from evaluations both in vitro and in vivo. In our study, the mechanism of switchable theranostics, the strategy of combined photodynamic and photothermal therapy, and the smart nanoengineering technology of phthalocyanines with poor water solubility can be applied to other phthalocyanines or phthalocyanine-like phototherapy agents.