Ultrabright NIR-II Emissive Polymer Dots for Metastatic Ovarian Cancer Detection

Intraoperative diagnosis of metastatic tumors is of significant importance to the treatment of ovarian cancer. NIR-II fluorescence imaging holds great promise for facile detection of tumor in situ with high sensitivity and resolution. Herein, a kind of NIR-II fluorescent polymer dots (NIR-II Pdots) with high brightness is developed for real-time detection of metastatic ovarian cancer via NIR-II fluorescence imaging. The NIR-II Pdots are constructed via the self-assembly of NIR-II emissive aggregation induced emission luminogens (NIR-II AIEgens) and poly (styrene)-graft-poly(ethylene glycol) in water. Such NIR-II Pdots show very high fluorophore contents of nearly 30% and high quantum yield of 5.4% at emission maximum near 1020 nm. Further modification of the NIR-II Pdots with targeting peptides yields NIR-II Pdots-GnRH, which can afford enhanced affinity of NIR-II Pdots to ovarian cancer. Upon intravenous injection of the NIR-II Pdots, whole-body organs and vessels, peritoneal and lymphatic metastases of ovarian cancer are clearly visualized by NIR-II fluorescence imaging. Under the guidance of NIR-II fluorescence imaging, the metastatic foci with the diameter down to ≈2 mm can be facilely eliminated. The results indicate preclinical potential value of the NIR-II Pdots for metastatic ovarian cancer detection.