Targeted imaging of colorectal dysplasia in living mice with fluorescence microendoscopy

Area of Science:

• Biomedical optics
• Gastroenterology
• Molecular imaging

Background:

• Colorectal dysplasia is a precancerous condition.
• Early detection of dysplasia is crucial for preventing colorectal cancer.
• Current diagnostic methods can be limited in sensitivity and specificity.

Purpose of the Study:

• To validate the binding activity of a fluorescence-labeled peptide to colorectal dysplasia.
• To assess the utility of a miniature fiber microendoscope for in vivo imaging of dysplasia.
• To evaluate the potential of this technique for early colorectal cancer detection.

Main Methods:

• A fluorescence-labeled peptide (FITC-QPIHPNNM) was applied topically to colonic mucosa in mice.
• A miniature, flexible fiber microendoscope was used to image the colonic mucosa.
• Excitation light at 473 nm was delivered, and fluorescence intensity was measured.
• Imaging was performed at 10 Hz with 4 µm lateral resolution.

Main Results:

• The fluorescence-labeled peptide showed specific binding to colorectal adenomas.
• Adenomas exhibited more than a two-fold greater fluorescence intensity compared to normal mucosa.
• Microendoscope images revealed irregular morphology characteristic of dysplasia in adenomas.

Conclusions:

• The fiber microendoscope effectively visualizes specific binding of a peptide to colorectal dysplasia in living mice.
• This technique demonstrates potential for sensitive, high-resolution imaging of precancerous lesions.
• This approach may offer a novel tool for early detection and diagnosis of colorectal dysplasia.