Researchers have developed a novel way to treat bladder cancer. Powered by urea, a waste substance found in urine, nanobots propel themselves to and penetrate the tumor to deliver their onboard radioactive treatment. After one dose, tumors in mouse models shrank by almost 90%, opening the door to a promising alternative treatment for this cancer, which tends to recur.
@Whelks_chance not sure. The part that would be left over is the silicon delivery module, which will have penetrated the tumour. Which then shrinks. Not clear how the body then disposes of it.