title: Visualization of pulmonary clearance mechanisms via noninvasive optical imaging validated by near-infrared flow cytometry.
abstract: In vivo optical imaging with near-infrared (NIR) probes is an established method of diagnostics in preclinical and clinical studies. However, the specificities of these probes are difficult to validate ex vivo due to the lack of NIR flow cytometry. To address this limitation, we modified a flow cytometer to include an additional NIR channel using a 752 nm laser line. The flow cytometry system was tested using NIR microspheres and cell lines labeled with a combination of visible range and NIR fluorescent dyes. The approach was verified in vivo in mice evaluated for immune response in lungs after intratracheal delivery of the NIR contrast agent. Flow cytometry of cells obtained from the lung bronchoalveolar lavage demonstrated that the NIR dye was taken up by pulmonary macrophages as early as 4-h post-injection. This combination of optical imaging with NIR flow cytometry extends the capability of imaging and enables complementation of in vivo imaging with cell-specific studies.
authors: Department of Radiology, Washington University School of Medicine, St. Louis, Missouri.
authors: Haiying
authors: H
authors: Zhou
authors: Sean P
authors: SP
authors: Gunsten
authors: Natalia G
authors: NG
authors: Zhegalova
authors: Sharon
authors: S
authors: Bloch
authors: Samuel
authors: S
authors: Achilefu
authors: J
authors: J
authors: Christopher Holley
authors: Daniel
authors: D
authors: Schweppe
authors: Walter
authors: W
authors: Akers
authors: Steven L
authors: SL
authors: Brody
authors: William C
authors: WC
authors: Eades
authors: Mikhail Y
authors: MY
authors: Berezin
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage*; D003952:Diagnostic Imaging / Q000379:methods*; D005434:Flow Cytometry / Q000379:methods*; D008168:Lung / Q000166:cytology*; D051379:Mice; D019265:Spectroscopy, Near-Infrared
chemical_list: D003287:Contrast Media
keywords: alveolar macrophage; flow cytometry; in vivo imaging; lung imaging; near-infrared