For the first time, nanorobots controlled by a magnetic field have managed to penetrate the dense substance of the vitreous body of the eye, which in the future can help in the treatment of a variety of eye diseases, from diabetic retinopathy to glaucoma, according to a new study published in Science Advances. Until now, these nanorobots could only move in biological fluids.
Ophthalmologists often face the need to inject drugs into the vitreous body, a transparent protein substance that fills the eye. Traditional methods of punctual injection of drugs make it relatively easy to reach the front of the eye, but not the same with the back of the eye. It also makes no sense to inject eye medications into the blood, since the retinal barrier in the blood will not let them pass.
Researchers from Germany, Denmark and China, under the leadership of Peer Fischer of the Institute of Intelligent Systems of the Max Planck Society, tried to solve this problem with the help of magnetic nanobots, whose movement can be controlled by an external magnetic field.
The scientists created spiral structures of silicon dioxide and nickel with a “head” with a diameter of 500 nanometers and a length of 2 microns. This corresponds roughly to the size of the cells of hyaluronic macromolecules (500 nanometers), which make up the vitreous body.
But the main secret of the nanorobots was a special sliding coating based on perfluorocarbon, which scientists observed in carnivorous plants of the genus Nepenthes. The capture tweezers of these predatory plants are covered with a layer of a very slippery substance that prevents the victim from coming out of the trap. Perfluorocarbon differs from other natural coatings, for example, those that cover lotus leaves, as well as its resistance to pressure and mechanical damage.
During the course of the experiment, the scientists placed water with nanorobots in a syringe and then injected it into the eye of a pig. Then, under the action of an induction magnetic field of approximately 8 milliliters, the nanorobots began to move in the vitreous body at a rate of approximately 10 microns per second. As a result, these robots were able to successfully overcome a distance of approximately 1 centimeter and reach the retina, and their movement could be controlled quite easily.
Recently, a team of researchers at the University of Bar-Ilan in Israel created a method in which they used DNA strands to create nanorobots that can fight diseases from within living beings. In their study, published in the journal Nature Nanotechnology, the researchers describe how they used various nanorobot structures by injecting them into cockroaches, and then observed how they worked together to target one of the insect cells.