Citation Details

Journal Article

Proteases; pathology; biological markers; fluorescence imaging reagents; in vivo imaging; fluorescence molecular tomography; FMT

Proteases play pivotal roles in the normal function of cells. In addition, the expression and activity of proteases are significantly upregulated in several pathologies, including cancer, arthritis and atherosclerosis, and hence they can be considered to be biological markers for these pathologies. The hydrolyzing activity of proteases has been used to generate a variety of fluorescent imaging reagents, the design and utility of which are reviewed here. The use of imaging reagents to visualize protease activity allows for improved detection of various pathologies as well as the ability to monitor the efficacy of therapies in vivo and provide molecular information regarding the nature of the pathology.

Journal Article

in vivo labelling; breast cancer; in vivo imaging

Bioorthogonal tetrazine cycloadditions have been applied to live cell labeling. Tetrazines react irreversibly with the strained dienophile norbornene forming dihydropyrazine products and dinitrogen. The reaction is high yielding, selective, and fast in aqueous media. Her2/neu receptors on live human breast cancer cells were targeted with a monoclonal antibody modified with a norbornene. Tetrazines conjugated to a near-infrared fluorochrome selectively and rapidly label the pretargeted antibody in the presence of serum. These findings indicate that this chemistry is suitable for in vitro labeling experiments, and suggests that it may prove a useful strategy for in vivo pretargeted imaging under numerous modalities.

Journal Article

in vivo imaging; microvascular morphology; near infrared; phenotype imaging

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Journal Article

pancreatic cancer; matrix metalloproteinases; near-infrared fluorescence; bioluminescence imaging; detection; in vivo imaging

N/A

Journal Article

FMT; in vivo imaging; ProSense; MMPSense

Eosinophils are multifunctional leukocytes that degrade and remodel tissue extracellular matrix through production of proteolytic enzymes, release of proinflammatory factors to initiate and propagate inflammatory responses, and direct activation of mucus secretion and smooth muscle cell constriction. Thus, eosinophils are central effector cells during allergic airway inflammation and an important clinical therapeutic target. Here we describe the use of an injectable MMP-targeted optical sensor that specifically and quantitatively resolves eosinophil activity in the lungs of mice with experimental allergic airway inflammation. Through the use of real-time molecular imaging methods, we report the visualization of eosinophil responses in vivo and at different scales. Eosinophil responses were seen at single-cell resolution in conducting airways using near-infrared fluorescence fiberoptic bronchoscopy, in lung parenchyma using intravital microscopy, and in the whole body using fluorescence-mediated molecular tomography. Using these real-time imaging methods, we confirmed the immunosuppressive effects of the glucocorticoid drug dexamethasone in the mouse model of allergic airway inflammation and identified a viridin-derived prodrug that potently inhibited the accumulation and enzyme activity of eosinophils in the lungs. The combination of sensitive enzyme-targeted sensors with noninvasive molecular imaging approaches permitted evaluation of airway inflammation severity and was used as a model to rapidly screen for new drug effects. Both fluorescence-mediated tomography and fiberoptic bronchoscopy techniques have the potential to be translated into the clinic.