Nanorobotic Hand Made of DNA Grabs Viruses for Detection or Inhibition

Researchers have developed a miniature, four-fingered “hand” from a single piece of DNA, designed to detect the virus responsible for COVID-19 with high sensitivity, and even prevent viral particles from entering cells to cause infection. Known as the NanoGripper, this nanorobotic hand can be customized to interact with other viruses or identify cell surface markers, potentially enabling targeted drug delivery, such as cancer treatments.

Drawing inspiration from the grasping ability of human hands and bird claws, researchers at the University of Illinois Urbana-Champaign (Champaign, IL, USA) designed the NanoGripper, which consists of four flexible fingers and a palm, all formed from one DNA nanostructure. Each finger features three joints, similar to a human finger, with its bending angle controlled by the design of the DNA scaffold. The fingers include DNA aptamers, molecules engineered to specifically bind to targets like the spike protein of the COVID-19 virus, causing the fingers to bend and encircle the target. The NanoGripper's base can attach to surfaces or other complexes, making it suitable for biomedical applications, such as sensing or drug delivery. For COVID-19 detection, the researchers integrated the NanoGripper with a photonic crystal sensor, resulting in a rapid 30-minute COVID-19 test that matches the sensitivity of traditional qPCR tests used in hospitals, which, while accurate, take longer than at-home tests.

Image: In this artist’s rendering, three “NanoGripper” hands wrap around a COVID-19 virus (Photo courtesy of Xing Wang/U. of I.)

Apart from diagnostics, the NanoGripper has potential applications in preventive medicine. The researchers discovered that when NanoGrippers were introduced into cell cultures exposed to COVID-19, the grippers surrounded the viruses, blocking the viral spike proteins from binding to the cell receptors, effectively preventing infection. In their article published in Science Robotics, the researchers explain that the NanoGripper can be easily modified to target other viruses, such as influenza, HIV, or hepatitis B. Additionally, they foresee using the NanoGripper for targeted drug delivery, where the fingers could be engineered to recognize specific cancer markers and deliver therapeutic agents directly to the affected cells.

“This approach has bigger potential than the few examples we demonstrated in this work,” said Xing Wang, a professor of bioengineering and of chemistry at the U. of I., who led the research team. “There are some adjustments we would have to make with the 3D structure, the stability and the targeting aptamers or nanobodies, but we’ve developed several techniques to do this in the lab. Of course it would require a lot of testing, but the potential applications for cancer treatment and the sensitivity achieved for diagnostic applications showcase the power of soft nanorobotics.”