ABSTRACT
Near-infrared (NIR) fluorescent imaging is a powerful tool for the non-invasive visualization of the inner structure of living organisms. Recently, NIR fluorescence imaging at 1000-1400 nm (second optical window) has been shown to offer better spatial resolution compared with conventional NIR fluorescence imaging at 700-900 nm (first optical window). Here we report lead sulfide (PbS) quantum dots (QDs) and their use for in vivo NIR fluorescence imaging of cerebral venous thrombosis in septic mice. Highly fluorescent PbS QDs with a 1100 nm emission peak (QD1100) were prepared from lead acetate and hexamethyldisilathiane, and the surface of QD1100 was coated with mercaptoundecanoic acid so as to be soluble in water. NIR fluorescence imaging of the cerebral vessels of living mice was performed after intravascular injection (200-300 µL) of QD1100 (3 µM) from a caudal vein. By detecting the NIR fluorescence of QD1100, we achieved non-invasive NIR fluorescence imaging of cerebral blood vessels through the scalp and skull. We also achieved NIR fluorescence imaging of cerebral venous thrombosis in septic mice induced by the administration of lipopolysaccharide (LPS). From the NIR fluorescence imaging, we found that the number of thrombi in septic mice was significantly increased by the administration of LPS. The formation of thrombi in cerebral blood vessels in septic mice was confirmed by enzyme-linked immunosorbent assay (ELISA). We also found that the number of thrombi significantly decreased after the administration of heparin, an inhibitor of blood coagulation. These results show that NIR fluorescence imaging with QD1100 is useful for the evaluation of the pathological state of cerebral blood vessels in septic mice.
Subject(s)
Lead/administration & dosage , Quantum Dots/chemistry , Sepsis/complications , Sulfides/administration & dosage , Venous Thrombosis/diagnostic imaging , Animals , Brain/diagnostic imaging , Disease Models, Animal , HeLa Cells , Humans , Lead/chemistry , Mice , Optical Imaging/methods , Optical Imaging/veterinary , Quantum Dots/administration & dosage , Sulfides/chemistry , Venous Thrombosis/etiologyABSTRACT
Compact SNAP ligand-conjugated quantum dots (<10 nm) with high colloidal stability over a wide range of pH (5-9) have been synthesized as fluorescent probe for the single-molecule imaging of dynein motor protein.
Subject(s)
Dyneins/chemistry , Fluorescent Dyes/chemistry , Quantum Dots , S-Nitroso-N-Acetylpenicillamine/chemistry , Ligands , Spectrometry, FluorescenceABSTRACT
We report a one-step synthetic strategy for the preparation of recombinant protein (EGFP-Protein G)-coated PbS quantum dots for dual (visible and second-NIR) fluorescence imaging of breast tumors at the cellular and whole-body level.
Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Green Fluorescent Proteins/chemistry , Lead/chemistry , Microscopy, Fluorescence, Multiphoton/methods , Quantum Dots , Selenium Compounds/chemistry , Animals , Cell Line, Tumor , Coated Materials, Biocompatible/chemical synthesis , Green Fluorescent Proteins/genetics , Humans , Image Enhancement/methods , Infrared Rays , Lead/radiation effects , Mice , Mice, Nude , Recombinant Proteins/pharmacokinetics , Reproducibility of Results , Selenium Compounds/radiation effects , Sensitivity and Specificity , Whole Body Imaging/methodsABSTRACT
To detect single molecules within the optical diffraction limit (< ca. 200 nm), a multicolored imaging technique is developed using Halo-ligand conjugated quantum dots (Halo-QDs; <6 nm in diameter). Using three types of Halo-QDs, multicolored single-molecule fluorescence imaging of GPCR proteins in Dictyostelium cells is achieved.
