Real-Time GPS for the Body's Tiny Robots
Nanorobots have shown great promise in precision medicine over the past few decades. Yet one key challenge remains: how to track and guide these tiny devices in real time as they move through complex physiological environments.
Existing imaging approaches often require long exposure times to detect ionising radiation or suffer from blurred images due to strong light scattering in living tissues.
The NIR-II Breakthrough
A research team led by Professor Feifei Wang from the Department of Electrical and Computer Engineering at the University of Hong Kong (HKU) has developed the first near-infrared II (NIR-II, 1,000–3,000 nm) fluorescence vision platform for magnetic nanorobot navigation.
This platform enables clear, real-time visual feedback for guiding nanorobots inside living bodies, opening new possibilities for image-guided precision therapy.
"The key question is how we can monitor nanorobots in the body with high specificity, sensitivity and clarity," said Professor Wang. "NIR-II fluorescence navigation offers superior contrast, resolution and penetration depth because light scattering is reduced and tissue autofluorescence is diminished at wavelengths above 1,000 nm."
GPS-Like Map for Navigation
The team's platform supports two-plex NIR-II imaging at different wavelengths, creating a "GPS-like map" for nanorobot navigation. This allows researchers to simultaneously visualise both the nanorobots and their target sites in real time, enabling precise in vivo locomotion with high molecular specificity and sensitivity.
"These NIR-II magnetic nanorobots are highly stable, even in the acidic environment of the stomach," said Dr Zideng Dai, first author of the study. "We successfully achieved targeted drug delivery to the gastrointestinal tract for the treatment of inflammatory bowel disease."
Performance Breakthrough
The NIR-II magnetic nanorobots demonstrated precise locomotion in the peritoneal cavity, hindlimb, liver, spleen and lower gastrointestinal tract in live mouse models. Compared with previous approaches, the platform provided:
- Higher-resolution visual feedback with superior clarity
- Locomotion speeds more than 100 times faster
- Approximately 30% higher delivery efficiency
Implications for Precision Medicine
This NIR-II nanorobot technology offers a promising new strategy for precise, image-guided drug delivery, with potential applications in the treatment of inflammatory diseases, tumours and other conditions requiring targeted therapy.
The research was published in the journal Science Advances, in an article entitled "Real-Time Near-Infrared II Fluorescence Navigation of Magnetic Nanorobots for Image-Guided Therapy".
