A Photostable Far-Red/Near-Infrared Conjugated Polymer Photosensitizer with Aggregation-Induced Emission for Image-Guided Cancer Cell Ablation

Far-red (FR)/near-infrared (NIR) photosensitizer is highly desirable in image-guided photodynamic cancer therapy. Herein, a new conjugated polymer of poly(1,2-bis(4-((6-bromohexyl)oxy)phenyl)-1,2-diphenylethene- co-alt -9,10-anthraquinone) (PTPEAQ) consisting of tetraphenylethylene (TPE), an iconic aggregation-induced emission (AIE) active group as the electron donor, and anthraquinone (AQ) as the acceptor, is prepared for the first time through one-pot Suzuki polymerization. Encapsulation of PTPEAQ with a block copolymer followed by surface functionalization with anti-Her2 affibody yields PTPEAQ-NP-HER2. It shows bright AIE-active FR/NIR emission and efficient singlet oxygen generation under visible light irradiation, which has been successfully used for photodynamic cancer cell ablation using SKBR-3 cells, a type of breast cancer cell with HER2 overexpression on cell membrane, as an example.