Tiny robots swim through the eye when propelled by a magnetic field — a technology that could one day be used to deliver drugs to currently inaccessible tissues.
Treatments for the retina, which lies at the back of the eye, usually involve the administration of drugs to the front of the eye. But as medicine diffuses to the retina, it can become less effective.
Tian Qiu and Peer Fischer at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany, and their colleagues created drug-delivery vehicles in the form of microscopic glass corkscrews. The researchers deposited iron on the devices, and then coated each tiny screw with a slippery liquid designed to ease its path through the mesh of collagen inside the eye.
After injecting the 2-micrometre-long corkscrews into a pig’s eyeball, the team used a rotating magnetic field to propel the robots to a targeted region on the retina. The robots reached the back of the eye in one-tenth of the time it would have taken for a drug molecule to diffuse to the same location. The authors say that the devices could allow for faster drug delivery with fewer side effects than those of current methods.