Tiny Soft Robots Dissolve Painful Kidney Stones with Targeted Drug Delivery

Kidney stones are solid deposits that form inside the urinary tract, affecting about 12% of people and often recurring. Current treatments for uric acid stones include painkillers and oral dissolving medication, which can take weeks or months to work, or surgery in urgent cases when stones block urine flow. Now, researchers have developed a minimally invasive approach to dissolve stones more quickly and help patients pass them in days.

An international research team led by the University of Waterloo (Waterloo, ON, Canada) has created a soft, flexible robotic system to target kidney stones directly in the urinary tract. The technique uses thin, spaghetti-like strips about a centimeter long, fitted with magnets and loaded with the enzyme urease. Operated by doctors through a robotic arm, the robots are guided to the stones, where the enzyme reduces urine acidity, dissolving stones into passable fragments.

The system was tested in a life-size, 3D-printed urinary tract model to simulate real conditions. The magnetic strips can be precisely moved into place using a revolving magnet on a robotic arm, while their soft design allows safe navigation through delicate urinary tissues. A paper on the work appeared in Advanced Healthcare Materials.

The researchers believe this targeted method could be especially valuable for recurring stone formers who cannot tolerate oral medication or face surgical risks from chronic infections or other health conditions. By accelerating stone dissolution, it could reduce pain duration, lower the need for invasive procedures, and ease the burden on healthcare systems.

The next steps for the project include large-animal studies, refining the control system, and integrating real-time ultrasound imaging for precise positioning. The team's goal is to provide a viable alternative for patients who need faster relief without surgery.

“Our goal is to provide an effective alternative to existing treatment methods,” said Dr. Veronika Magdanz, professor at the University of Waterloo. “We hope accelerated stone dissolution will relieve the pain faster and help patients pass stones quicker.”

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