title: Targeted detection of murine colonic dysplasia in vivo with flexible multispectral scanning fiber endoscopy.
abstract: Gastrointestinal cancers are heterogeneous and can overexpress several protein targets that can be imaged simultaneously on endoscopy using multiple molecular probes. We aim to demonstrate a multispectral scanning fiber endoscope for wide-field fluorescence detection of colonic dysplasia. Excitation at 440, 532, and 635 nm is delivered into a single spiral scanning fiber, and fluorescence is collected by a ring of light-collecting optical fibers placed around the instrument periphery. Specific-binding peptides are selected with phage display technology using the CPC;Apc mouse model of spontaneous colonic dysplasia. Validation of peptide specificity is performed on flow cytometry and in vivo endoscopy. The peptides KCCFPAQ, AKPGYLS, and LTTHYKL are selected and labeled with 7-diethylaminocoumarin-3-carboxylic acid (DEAC), 5-carboxytetramethylrhodamine (TAMRA), and CF633, respectively. Separate droplets of KCCFPAQ-DEAC, AKPGYLS-TAMRA, and LTTHYKL-CF633 are distinguished at concentrations of 100 and 1 μM. Separate application of the fluorescent-labeled peptides demonstrate specific binding to colonic adenomas. The average target/background ratios are 1.71 ± 0.19 and 1.67 ± 0.12 for KCCFPAQ-DEAC and AKPGYLS-TAMRA, respectively. Administration of these two peptides together results in distinct binding patterns in the blue and green channels. Specific binding of two or more peptides can be distinguished in vivo using a novel multispectral endoscope to localize colonic dysplasia on real-time wide-field imaging.
authors.affiliation: University of Michigan, Department of Internal Medicine, Division of Gastroenterology, 109 Zina Pitcher Pl. BSRB 1522, Ann Arbor, Michigan 48109-2200, USA.
authors.forename: Sharon J
authors.initials: SJ
authors.lastname: Miller
authors.forename: Cameron M
authors.initials: CM
authors.lastname: Lee
authors.forename: Bishnu P
authors.initials: BP
authors.lastname: Joshi
authors.forename: Adam
authors.initials: A
authors.lastname: Gaustad
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Seibel
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Wang
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000818:Animals; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000473:pathology*; D020776:Endoscopes, Gastrointestinal; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007089:Image Enhancement / Q000295:instrumentation*; D051379:Mice; D018345:Mice, Knockout; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation*; D057054:Molecular Imaging / Q000295:instrumentation*