A facile phototheranostic nanoplatform integrating NIR-II fluorescence/PA bimodal imaging and image-guided surgery/PTT combinational therapy for improved antitumor efficacy

Phototheranostic with highly integrated functions is an attractive platform for cancer management. It remains challenging to develop a facile phototheranostic platform with complementary bimodal imaging and combinational therapy capacity. Herein, the small-molecule cyanine IR780 loaded liposomes have been harnessed as a nanoplatform to simultaneously realize photoacoustic (PA)/the second near-infrared window (NIR-II) fluorescence imaging and image-guided surgery/adjuvant photothermal therapy (PTT). This nanoplatform exhibits attractive properties like uniform controllable size, stable dispersibility, NIR-II fluorescence emission, photothermal conversion, and biocompatibility. Benefiting from the complementary PA/NIR-II fluorescence bimodal imaging, this nanoplatform was successfully applied in precise vasculature delineation and tumor diagnosis. Interestingly, the tumor was clearly detected by NIR-II fluorescence imaging with the highest tumor-to-normal-tissue ratio up to 12.69, while signal interference from the liver was significantly reduced, due to the difference in the elimination rate of the nanoplatform in the liver and tumor. Under the precise guidance of the image, the tumor was accurately resected, and the simulated residual lesion after surgery was completely ablated by adjuvant PTT. This combined therapy showed improved antitumor efficacy over the individual surgery or PTT. This work develops a facile phototheranostic nanoplatform with great significance in accurately diagnosing and effectively treating tumors using simple NIR light irradiation.