Call it another case of science fiction becoming scientific fact. Researchers have long dreamed of developing tiny robots that could roam about inside our bodies, delivering drugs with unprecedented precision, and hunting down and destroying cancer cells. Scientists from China’s National Center for Nanoscience and Technology (NCNT) and Arizona State University said they had developed robots a few hundred nanometers across — there are 25 million nanometers in an inch — and when they injected them into the bloodstream of mice, the nanorobots could shrink tumors by blocking their blood supply. The nanorobots were made from sheets of DNA rolled into tubes containing a blood-clotting drug. On the outside, the researchers placed a small DNA molecule that binds with a protein found only in tumors. When the bots reached tumors, this molecule attached to the protein, triggering the DNA tube to unroll and release the drug. Most cancer drugs typically have nasty side effects be
