Deep inside a mouse’s body, a swarm of microscopic robots glides through tissue with the quiet precision of a satellite-guided submarine—except these nanorobots are no bigger than a few human cells, and they’re being steered in real time from outside the body. In a lab at The University of Hong Kong, Professor Feifei Wang and her team have achieved what once seemed like science fiction: tracking and guiding magnetic nanorobots through living systems with clarity and speed never seen before. Their breakthrough, published in Science Advances, hinges on a new near-infrared fluorescence platform that functions like a GPS for medicine, offering a clear window into the body’s inner pathways.
The challenge of guiding nanorobots has long plagued medical innovation. While tiny therapeutic carriers can be designed to deliver drugs directly to diseased tissue, seeing them move through the body in real time has been nearly impossible. Traditional imaging either exposes patients to radiation or produces blurry, delayed visuals due to light scattering in tissues. Wang’s team solved this by developing the first NIR-IIb (1,000–3,000 nm) fluorescence vision platform, which cuts through biological noise with remarkable clarity. At these longer wavelengths, light scatters less and natural tissue glow fades, allowing for high-contrast, real-time imaging.
The system supports two-plex imaging—meaning researchers can simultaneously track both the nanorobots and their target organs, like watching a moving dot approach a destination on a live map. In live mouse models, the team guided nanorobots to the peritoneal cavity, liver, spleen, hindlimb, and lower gastrointestinal tract with unprecedented control. The nanorobots, stable even in the harsh acidity of the stomach, delivered drugs directly to inflamed areas of the gut, offering a promising path forward for treating inflammatory bowel disease. Speed and efficiency soared: locomotion was over 100 times faster than with previous methods, and drug delivery efficiency increased by approximately 30%.
“This NIR-II fluorescence navigation offers superior contrast, resolution and penetration depth,” says Dr. Zideng Dai, the study’s first author. The implications stretch far beyond the gut. With this level of precision, tumors could be targeted with minimal collateral damage, chronic inflammation silenced at its source, and therapies delivered exactly where and when they’re needed. The platform doesn’t just track—it guides, enabling active control of nanoscale vehicles deep within the body.
While human trials are still ahead, this technology marks a turning point in how we think about internal medicine. No longer limited to systemic treatments that affect the whole body, we’re moving toward a future where therapy is as precise as a laser. And somewhere in a lab in Hong Kong, tiny robots are already showing us the way.