Targeting drugs inside the body without causing collateral damage has always been a challenge. A new study published in Nature’s Science Journal shows a path forward. Researchers have created tiny, remote-controlled microrobots that can swim through blood vessels, deliver drugs exactly where needed and then safely dissolve. These robots are about the size of a grain of sand. They’re made from gelatine packed with medicine and magnetic nanoparticles so doctors can steer them from outside the body.
The team tested the system in pigs and sheep, both close to humans in vascular size and complexity. Using magnetic fields generated outside the body, the microrobots could roll, swim against blood flow and cruise along vessels at speeds up to 40 centimeters per second. Catheters were used to place them at the starting point, and X-ray imaging allowed real-time tracking with millimeter-level accuracy.
In more than 95 percent of pig trials, the microrobots deposited the drug exactly where it was supposed to go. No more flooding the whole body with drugs that can cause toxic effects. That’s crucial, because nearly one-third of drug candidates fail due to toxicity. What makes this work stand out is scalability. Earlier microrobot systems worked only in tiny animals or narrow lab setups. This one works inside large animals with human-sized anatomy, and the materials used are already known to be biocompatible.
“The demonstrations are compelling but still preclinical, If progress remains continues – the first medical uses could appear within five to ten years.” said Wei Gao of Caltech.”
Researchers controlled drug release using rapidly changing magnetic fields, which heated and broke down the gelatine shell. Only iron-oxide nanoparticles remained, and teams will now investigate how safely the body clears those. This breakthrough took two decades of engineering work. The challenge was finding materials small enough to travel through tiny blood vessels, but responsive enough to strong magnetic control. Although, microrobots aren’t ready for hospitals yet, but this study shows they may soon become a new class of targeted therapy. If human trials succeed, doctors may one day guide tiny robots through the bloodstream to deliver drugs with unmatched precision and safety.
