Icing on the Cake: Integrating Optical Fiber with Second Near‐Infrared Aggregation‐Induced Emission Luminogen for Exceptional Phototheranostics of Bladder Cancer

Abstract Bladder cancer is a common urological malignancy characterized by high morbidity, high recurrence rate and high mortality, imposing heavy burdens on patients mentally and financially. The research pioneers a diagnostic and therapeutic approach that integrates a second near‐infrared (NIR‐II) multimodal phototheranostic platform with optical fiber‐mediated interventional phototherapy strategy, to implement a comprehensive diagnosis and “inside‐out” treatment of bladder cancer. The proposed molecule, namely BTO‐TTQ, is elaborately designed through electron donor/π‐bridge engineering and demonstrates satisfying NIR‐II emission with aggregation‐induced emission features, high photothermal conversion efficiency, and prominent generation of type I reactive oxygen species. Quantum chemical calculations and molecular dynamics simulations are employed to deeply elucidate the energy dissipation pathways of the excited state and the impact of intramolecular motion on their photophysical properties. Furthermore, under the guidance of NIR‐II fluorescent‐photoacoustic‐photothermal trimodal imaging, hyaluronic acid‐modified BTO‐TTQ nanoparticles exhibit exceptional performance in optical fiber‐mediated interventional phototherapy for air‐pouch bladder cancer models. This study thus brings a new insight into the development of superior versatile phototheranostics for clinical theranostics of bladder cancer.