Related Experiment Video
Updated: Jul 19, 2026
Murine Endoscopy for In Vivo Multimodal Imaging of Carcinogenesis and Assessment of Intestinal Wound Healing and Inflammation
Published on: August 26, 2014
Simultaneous fluorescence imaging of protease expression and vascularity during murine colonoscopy for colonic lesion
Martin A Funovics1, Herlen Alencar, Xavier Montet
1Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02129, USA.
Background:
Molecularly targeted fluorescent probes are currently being developed to improve the endoscopic detection of intestinal pathologic conditions.
Objective:
We report on the development and testing of a novel multichannel microendoscope capable of quantitatively reporting such probes simultaneously at different wavelengths in real time. We assessed the feasibility of detecting and quantifying beacons that can be activated by protease and correlating imaging with disease state.
Design:
The microendoscope consisted of a 20-gauge fiberoptic catheter and dichroic beam splitters that simultaneously display visible light, 700 nm and 800 nm near infrared (NIR) fluorescent light. NIR interchannel separation was tested on in vitro phantoms. Two mouse models were used (Apcmin(+/-) mice for colonic adenomas and CT26 murine colon cancer). A perfusion probe and one activated by protease at a separate wavelength were injected before endoscopic evaluation.
Results:
The microendoscope fluorochrome detection limit was approximately 10 fmol; ratio imaging in the NIR was accurate (+/-8% of true probe concentration between 0.3 to 100 microg/ml of a protease sensor). Both colonic adenomas and adenocarcinomas were clearly visible in the NIR channel on protease probe administration in live mice. Ratio imaging of protease activity/perfusion increased from healthy colon to adenomas to adenocarcinomas.
Limitations:
Evaluation across additional spontaneous tumor models may provide more data on the translation of these findings.
Conclusions:
Our data show the feasibility of multichannel microendoscopic imaging of molecular targets in vivo and that ratio imaging may provide a novel means for characterizing colonic lesions. When scaled up clinically, this could aid in increasing lesion detection and quantitative assessment of distinct molecular markers.
Insights
A new multichannel microendoscope can detect molecular targets in the intestine in real time. This technology shows promise for improved detection and characterization of colonic lesions during endoscopy.
Area of Science:
- Biomedical Engineering
- Gastroenterology
- Optical Imaging
Background:
- Molecularly targeted fluorescent probes are crucial for enhancing endoscopic detection of intestinal diseases.
- Current methods require advanced imaging techniques for accurate diagnosis.
Purpose of the Study:
- To develop and test a novel multichannel microendoscope for simultaneous, real-time quantitative reporting of molecular probes.
- To assess the feasibility of detecting protease-activated beacons and correlating imaging with disease states.
Main Methods:
- A 20-gauge fiberoptic catheter microendoscope was designed with dichroic beam splitters for visible and near-infrared (NIR) fluorescence detection (700 nm and 800 nm).
- In vitro phantom testing evaluated NIR interchannel separation.
- Two mouse models (Apcmin(+/-) and CT26) were used, with injected perfusion and protease-activated probes before endoscopic evaluation.
Main Results:
- The microendoscope achieved a fluorochrome detection limit of approximately 10 fmol.
- Accurate ratio imaging in the NIR (+/-8%) quantified protease sensor concentrations.
- Colonic adenomas and adenocarcinomas were visualized in the NIR channel, with increased ratio imaging of protease activity/perfusion correlating with disease progression.
Conclusions:
- Multichannel microendoscopic imaging of molecular targets in vivo is feasible.
- Ratio imaging offers a novel method for characterizing colonic lesions.
- Clinical translation could improve lesion detection and quantitative assessment of molecular markers.
