Gadolinium-Functionalized Aggregation-Induced Emission Dots as Dual-Modality Probes for Cancer Metastasis Study

Abstract

Understanding the localization and engraftment of tumor cells at postintravasation stage of metastasis is of high importance in cancer diagnosis and treatment. Advanced fluorescent probes and facile methodologies for cell tracing play a key role in metastasis studies. In this work, we design and synthesize a dual-modality imaging dots with both optical and magnetic contrast through integration of a magnetic resonance imaging reagent, gadolinium(III), into a novel long-term cell tracing probe with aggregation-induced emission (AIE) in far-red/near-infrared region. The obtained fluorescent-magnetic AIE dots have both high fluorescence quantum yield (25%) and T1 relaxivity (7.91 mM-1 s-1) in aqueous suspension. After further conjugation with a cell membrane penetrating peptide, the dual-modality dots can be efficiently internalized into living cells. The gadolinium(III) allows accurate quantification of biodistribution of cancer cells via intraveneous injection, while the high fluorescence provides engraftment information of cells at single cellular level. The dual-modality AIE dots show obvious synergistic advantages over either single imaging modality and hold great promises in advanced biomedical studies. A dual-modality imaging probe is developed through integration of gadolinium(III) into fluorescent dots with aggregation-induced emission (AIE). The obtained fluorescent-magnetic AIE dots allow accurate quantification of biodistribution and engraftment in organ tissues with single cell resolution, which provide vital information of cancer cell behavior at postintravasation stage of metastasis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.