Nanoconstruction of curcuminoid boron difluoride dyes with aggregation-induced emission for bright near-infrared fluorescence imaging of malignant tumor†

Abstract

Curcuminoid boron difluoride dyes have garnered significant attention in the realm of bioimaging, primarily owing to their excellent photophysicochemical properties. However, the strong hydrophobicity limits their optimal near-infrared (NIR) fluorescence emission, and the synthesis process is complicated. In this study, Curc-TPA, a curcuminoid boron difluoride derivative with a high fluorescence quantum yield, was facilely synthesized and surprisingly exhibited aggregation-induced NIR emission in a dimethyl sulfoxide/water mixture. The compound self-assembled into stable and homogeneous nanoparticles through hydrophobic interaction with the amphiphilic polymer 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol), which showed enhanced aggregation-induced emission (AIE) capacity in the NIR region. The nanoparticles specifically enriched at the tumor site due to the enhanced penetration and retention effect and exhibited bright fluorescence in vitro and in vivo. Notably, they showed satisfactory hematological compatibility and unobservable cellular and histological toxicity. Therefore, they are of promising clinical significance in the AIE-enhanced NIR fluorescence imaging-visualized precise diagnosis of cancer.