Photovoltaic polymer Photosensitizer-Doped Nano-Therapeutic reagent for in vivo enhanced bioimaging guided photodynamic therapy

For tumor imaging guided photodynamic therapy process, the conundrum of achieving high fluorescence efficiency and singlet oxygen generation efficiency concurrently under the excitation condition of visible light has become a major obstacle to the integration of diagnosis and treatment. For lack of effective methods to resolve this issue, constructing a single photosensitizer with high quantum yield, efficient singlet oxygen generation, stable red emission, excellent photo-stability and low dark toxicity is challenging. In this research, the performance bottleneck is broken by designing an effective donor–acceptor system with excellent imaging and great photodynamic therapy capability through judiciously incorporating a novel polymer (J71) into a hydrophobic conjugated polymer, which is the first time of utilizing this celebrity photovoltaic material as a photosensitizer in photodynamic therapy process. Through fluorescence resonance energy transfer from conjugated polymer to J71, the singlet oxygen production rate of nanoparticles can be enhanced to 0.704. The nanoparticle also exhibits relatively high quantum yield of 0.255. The relatively strong singlet oxygen yield and relatively high fluorescence efficiency of nanoparticle was competitive with other inorganic and organic photosensitizers. Moreover, the J71 as a novel photosensitizer is a kind of 2D-conjugated polymer, which displayed promising photo-stability than traditional porphyrin photosensitizer. The prepared nanoparticles present all desired properties. A series of in vivo and in vitro results revealed the excellent fluorescence imaging capability and noteworthy anti-tumor ability, indicative of this system has great potential application in tumor imaging guided photodynamic therapy.