Surfactant-stripped J-aggregates of azaBODIPY derivatives: All-in-one phototheranostics in the second near infrared window

Development of multifacted phototheranostics with bright fluorescence and absorbance in the second near infrared (NIR-II) window is very appealing for precise cancer diagnosis and treatment, but still challenging nowadays. Herein, we synthesize a hydrophobic annularly fused azaBODIPY (termed as HBP) molecule with sharp NIR absorbance peaked at 878 nm and bright NIR-II fluorescence. With Pluronic F127 as the surfactant and hydrophobic paclitaxel (PTX) as the spacer, such HBP molecule would self-assemble to form surfactant-stripped HBP/PTX micelles with absorption peak red-shifted to 1012 nm and intrinsic NIR-II fluorescence negligibly disturbed. We found that such HBP/PTX micelles can be utilized as a bimodal NIR-II nano-probe to enable real-time tracking of lymph nodes and tumors under an NIR-II fluorescence imaging system, as well as clear visualization of tumor microvasculatures under an NIR-II photoacoustic imaging system. Furthermore, together with 1064 nm laser exposure, such HBP/PTX micelles would synergistically suppress the growth of tumors grown on the mice upon tumor accumulation. This work highlights the concise preparation of a type of all-in-one NIR-II phototheranostics from the newly synthesized HBP molecules, thereby enables NIR-II fluorescence/photoacoustic bimodal imaging guided synergistic cancer treatment via the NIR-II laser boosted photothermal therapy and chemotherapy.