All-in-One Phototheranostics: Single Laser Triggers NIR-II Fluorescence/Photoacoustic Imaging Guided Photothermal/Photodynamic/Chemo Combination Therapy

Development of single near-infrared (NIR) laser triggered phototheranostics for multimodal imaging guided combination therapy is highly desirable but is still a big challenge. Herein, a novel small-molecule dye DPP-BT is designed and synthesized, which shows strong absorption in the first NIR window (NIR-I) and fluorescence emission in the second NIR region (NIR-II). Such a dye not only acts as a dual-modal contrast agent for NIR-II fluorescence and photoacoustic (PA) imaging, but also serves as a combined therapeutic agent for photothermal therapy (PTT) and photodynamic therapy (PDT). The single NIR laser triggered all-in-one phototheranostic nanoparticles are constructed by encapsulating the dye DPP-BT, chemotherapy drug DOX, and natural phase-change materials with a folic acid functionalized amphiphile. Notably, under NIR laser irradiation, DOX can effectively release from such nanoparticles via NIR-induced hyperthermia of DPP-BT. By intravenous injection of such nanoparticles into Hela tumor-bearing mice, the tumor size and location can be accurately observed via NIR-II fluorescence/PA dual-modal imaging. From in vitro and in vivo therapy results, such nanoparticles simultaneously present remarkable antitumor efficacy by PTT/PDT/chemo combination therapy, which is triggered by a single NIR laser. Overall, this work provides an innovative strategy to design and construct all-in-one nanoplatforms for clinical phototheranostics.