The development of effective cancer treatment methods has become extremely urgent due to the rapid growth of cancer patients. Comparing to conventional therapeutic methods for cancer, photothermal therapy (PTT) and photodynamic therapy (PDT) are two main noninvasive phototherapies due to the low side-effects, high selectivity and efficiency. PTT and PDT are usually induced by near-infrared (NIR) light then the excited agents inside tumor can generate heat or reactive oxygen species (ROS) to kill tumor cells. However, most of inorganic agents face big challenges of the potential far-reaching toxicity and bio-refractory in clinic. Differently, small molecular organic dyes as photothermal agents usually presents low-toxicity, good biodegradability and fluorescence in biological tissue. 

Herein, we have designed and synthesized a series of NIR-absorbing photosensitizers (PSs), based on DPP and Bodipy derivatives. After self-assembly, organic nanoparticles (NPs), with excellent tumor-targeting performance and high ROS generation ability or photothermal conversion, can be obtained. Moreover, the NPs can be passive targeted to tumor sites by the enhanced permeability and retention (EPR) effect and photoacoustic imaging can visualize the tumor site for real-time monitoring during the therapeutic process. What’s more, by the assistance of pharmacokinetics, the properties and mechanisms of NIR-absorbing Nano-PSs were studied, which provided a more effective and smart method for accurate imaging of cancer tumor and phototherapy.