Versatile phototheranostic system: Aza-BODIPY-based nanoparticles with B,O-chelated core and diiodine

The heavy atom effect is widely recognized for its ability to enhance the photodynamic effect, but it also gives rise to concerns about fluorescence quenching and low photothermal conversion efficiency. In this study, we introduced iodine atoms into B,O-chelated aza-BODIPY and coated them with DSPE-PEG2000 to achieve high singlet oxygen quantum yields (64.9 %), while simultaneously maintaining excellent fluorescence emission (0 = 0.94 %) and photothermal conversion capability (PCE = 33.8 %). The B,O-chelated aza-BODIPY derivative shows a remarkable synergistic and improved phototherapy therapeutic performance mainly by the innovative enhancement of the ir-conjugated structure from the B,O-chelated structure and partial weakening of intermo-lecular ir-ir stacking from the steric hindrance of iodine atoms, which was validated through in vivo and in vitro tumor diagnosis and elimination experiments, utilizing state-of-the-art fluorescence imaging, photoacoustic imaging, and photothermal imaging for multimodal imaging-guided photodynamic therapy and photothermal therapy. This groundbreaking approach effectively overcomes the limitations of the traditional heavy atom ef-fect, and presents a pioneering perspective on constructing a versatile phototheranostic system for precise and efficient tumor treatment. By effectively addressing the challenges posed by the heavy atom effect and maximizing the capabilities of the photosensitizer, we pave the way for more accurate and effective approaches in combating tumors.

Automated summary

This study successfully overcame the limitations of the heavy atom effect by introducing iodine atoms and innovatively enhancing the structure while weakening stacking behavior, achieving high efficiency and precision in photodynamic therapy and photothermal therapy.