Wireless, Deep-Seeing Smart Pill: A NIR-II Fluorescence Imaging Capsule Endoscope for Gastrointestinal Cancer

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Gastroenterology

Background:

• Current capsule endoscopy (CE) faces limitations in penetration depth and signal-to-noise ratio (SNR) due to tissue optical properties.
• These limitations can lead to missed diagnoses of deep or small gastrointestinal lesions.

Purpose of the Study:

• To develop and evaluate a near-infrared-II fluorescent imaging capsule endoscope (NIR-II FICE) for early gastrointestinal cancer detection.
• To leverage NIR-II fluorescence imaging for enhanced sensitivity, resolution, and tissue penetration.

Main Methods:

• Development of a wireless-powered, magnetically controlled NIR-II FICE system.
• Utilization of NIR-II fluorescent nanoprobe (FNP) for targeted fluorescence detection above 900 nm.
• Ex vivo and in vivo experiments to assess imaging performance, including penetration depth, SNR, and contrast.

Main Results:

• NIR-II FICE detected FNP at concentrations as low as 5 µg mL⁻¹.
• Imaging resolution down to 100 µm was achieved.
• Ex vivo experiments demonstrated a penetration depth of 4 mm in porcine gastric tissue with SNR > 13 dB and contrast > 0.5.
• In vivo imaging of lesions in nude mice was successful.

Conclusions:

• NIR-II FICE represents a significant advancement in non-invasive gastrointestinal disease diagnosis.
• This novel platform offers high sensitivity, resolution, and deep tissue penetration for early cancer detection.
• The system's wireless power and magnetic control enhance its clinical applicability.