Biochromoendoscopy: molecular imaging with capsule endoscopy for detection of adenomas of the GI tract.
BACKGROUND
Current capsule endoscopy (CE) provides minimally invasive technology for GI imaging but has limited ability to discriminate different types of polyps. Near infrared fluorescent (NIRF) probes activated by biomarkers upregulated in adenomas (eg, cathepsin B) are potentially powerful tools to distinguish premalignant or malignant lesions from benign or inflammatory lesions.


OBJECTIVE
To examine whether CE can be integrated with NIRF probes to detect adenomas and whether cathepsin B-activated NIRF probes are activated by benign or inflammatory lesions.


METHODS
Mouse models of adenomas, hyperplactic/lymphoid polyps, and acute or chronic intestinal inflammation were injected intravenously with a cathepsin B-activated probe (Prosense 680). Dissected intestine was imaged with CE under white or NIRF light. For NIRF excitation (680 nm), dichroic and emission (700 nm) filters were combined with CE when images were recorded. Prosense 680 samples with or without protease were used as positive and negative controls. CE-based imaging data were verified by using and independent imaging system (Xenogen IVIS system).


METHODS
Proof of principal that CE integrated with NIRF probes can detect and discriminate adenomas from other lesions.


RESULTS
CE-based NIRF imaging with Prosense 680 readily visualized adenomas, including in the colitis model. NIRF signals of different intensities were detected. Prosense 680 was not activated by benign or inflammatory lesions.


CONCLUSIONS
Optical filters external to the capsule were used.


CONCLUSIONS
We demonstrate proof of the principle that biochromoendoscopy-CE combined with molecular probes--provides a novel approach that differentiates adenomas from benign polyps and inflammatory lesions.
Zhang
Howard
H
Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Morgan
Douglas
D
Cecil
Gerald
G
Burkholder
Adam
A
Ramocki
Nicole
N
Scull
Brooks
B
Lund
P Kay
PK
D018256:Adenomatous Polyps / Q000175:diagnosis* / Q000473:pathology; D000818:Animals; D053704:Capsule Endoscopy / Q000379:methods*; D002401:Cathepsin B / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003113:Colonoscopy / Q000379:methods*; D003937:Diagnosis, Differential; D003952:Diagnostic Imaging / Q000379:methods; D004195:Disease Models, Animal; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis* / Q000473:pathology; D007275:Injections, Intravenous; D051379:Mice; D008810:Mice, Inbred C57BL; D008967:Molecular Biology; D015336:Molecular Probe Techniques; D015335:Molecular Probes; D011897:Random Allocation; D012307:Risk Factors; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation* / Q000379:methods
D015335:Molecular Probes; D002401:Cathepsin B