A Versatile Theranostic Nanoplatform with Aggregation‐Induced Emission Properties: Fluorescence Monitoring, Cellular Organelle Targeting, and Image‐Guided Photodynamic Therapy

Abstract Photosensitizers (PSs) play a key role in the photodynamic therapy (PDT) of tumors. However, commonly used PSs are prone to intrinsic fluorescence aggregation‐caused quenching and photobleaching; this drawback severely limits the clinical application of PDT, necessitating new phototheranostic agents. Herein, a multifunctional theranostic nanoplatform (named TTCBTA NP) is designed and constructed to achieve fluorescence monitoring, lysosome‐specific targeting, and image‐guided PDT. TTCBTA with a twisted conformation and D‐A structure is encapsulated in amphiphilic Pluronic F127 to form nanoparticles (NPs) in ultrapure water. The NPs exhibit biocompatibility, high stability, strong near‐infrared emission, and desirable reactive oxygen species (ROSs) production capacity. The TTCBTA NPs also show high‐efficiency photo‐damage, negligible dark toxicity, excellent fluorescent tracing, and high accumulation in lysosome for tumor cells. Furthermore, TTCBTA NPs are used to obtain fluorescence images with good resolution of MCF‐7 tumors in xenografted BALB/c nude mice. Crucially, TTCBTA NPs present a strong tumor ablation ability and image‐guided PDT effect by generating abundant ROSs upon laser irradiation. These results demonstrate that the TTCBTA NP theranostic nanoplatform may enable highly efficient near‐infrared fluorescence image‐guided PDT.