Flexible Endoscopy: Optical Molecular Imaging

Wheat germ agglutinin (WGA) is a lectin that shows differential binding to Barrett’s oesophagus and dysplasia. Imaging of fluorescently labelled WGA has the potential to increase the sensitivity and specificity of Barrett’s surveillance, but is confounded by tissue autofluorescence in the visible region where commercially available endoscopes are optimised for detection. To address this challenge, WGA was conjugated to a near-infrared fluorophore (IR800) for NIR fluorescence imaging, thus avoiding the visible autofluorescence background, and a bimodal endoscope capable of acquisition and coregistration of white light reflectance images for endoscopic guidance and of NIR fluorescence images for optical molecular imaging of WGA-IR800 was designed and built. This Chapter describes the design and development of this novel endoscope described and the preliminary biological validation carried out using ex vivo mouse and human tissues.