Tunable Ultrasmall Visible-to-Extended Near-Infrared Emitting Silver Sulfide Quantum Dots for Integrin-Targeted Cancer Imaging

摘要: The large size of many near-infrared (NIR) fluorescent nanoparticles prevents rapid extravasation from blood vessels and subsequent diffusion to tumors. This confines in vivo uptake the peritumoral space results high liver retention. In this study, we developed a viscosity modulated approach synthesize ultrasmall silver sulfide quantum dots (QDs) with distinct tunable light emission 500 1200 nm QD core diameter between 1.5 9 nm. Conjugation tumor-avid cyclic pentapeptide (Arg-Gly-Asp-DPhe-Lys) resulted monodisperse, water-soluble QDs (hydrodynamic < 10 nm) without loss peptide's binding affinity tumor-associated integrins (KI = 1.8 nM/peptide). Fluorescence electron microscopy showed that selective integrin-mediated internalization was observed only cancer cells treated peptide-labeled QDs, demonstrating unlabeled hydrophilic exhibit characteristics negatively charged dye molecules, which typically do not internalize cells. biodistribution profiles intravenously administered different mouse models reveal an exceptionally tumor-to-liver ratio, suggesting small sized evaded conventional opsonization spleen. seamless tunability over wide spectral range increase size, as well ease labeling bright noncytotoxic biomolecules, provides platform for multiplexing information, tracking trafficking single molecules cells, selectively targeting disease biomarkers living organisms premature circulating blood.