A tiny, four-fingered “hand” folded from a single piece of DNA can pick up the virus that causes COVID-19 for highly sensitive rapid detection and may even block viral particles from entering cells to contaminate them, University of Illinois Urbana-Champaign researchers report. Dubbed the NanoGripper, the nanorobotic hand also may very well be programmed to interact with other viruses or to acknowledge cell surface markers for targeted drug delivery, resembling for cancer treatment.
Led by Xing Wang, a professor of bioengineering and of chemistry on the U. of I., the researchers describe their advance within the journal Science Robotics.
Inspired by the gripping power of the human hand and bird claws, the researchers designed the NanoGripper with 4 bendable fingers and a palm, multi function nanostructure folded from a single piece of DNA. Each finger has three joints, like a human finger, and the angle and degree of bending are determined by the design on the DNA scaffold.
“We desired to make a soft material, nanoscale robot with grabbing functions that never have been seen before, to interact with cells, viruses and other molecules for biomedical applications,” Wang said. “We’re using DNA for its structural properties. It is robust, flexible and programmable. Yet even within the DNA origami field, that is novel when it comes to the design principle. We fold one long strand of DNA forwards and backwards to make the entire elements, each the static and moving pieces, in a single step.”
The fingers contain regions called DNA aptamers which can be specially programmed to bind to molecular targets — the spike protein of the virus that causes COVID-19, for this primary application — and trigger the fingers to bend to wrap across the goal. On the alternative side, where the wrist could be, the NanoGripper can attach to a surface or other larger complex for biomedical applications resembling sensing or drug delivery.
To create a sensor to detect the COVID-19 virus, Wang’s team partnered with a bunch led by Illinois electrical and computer engineering professor Brian Cunningham, who focuses on biosensing. They coupled the NanoGripper with a photonic crystal sensor platform to create a rapid, 30-minute COVID-19 test matching the sensitivity of the gold-standard qPCR molecular tests utilized by hospitals, that are more accurate than at-home tests but take for much longer.
“Our test may be very fast and easy since we detect the intact virus directly,” Cunningham said. “When the virus is held within the NanoGripper’s hand, a fluorescent molecule is triggered to release light when illuminated by an LED or laser. When a lot of fluorescent molecules are concentrated upon a single virus, it becomes vivid enough in our detection system to count each virus individually.”
Along with diagnostics, the NanoGripper could have applications in preventive medicine by blocking viruses from entering and infecting cells, Wang said. The researchers found that when NanoGrippers were added to cell cultures that were then exposed to COVID-19, multiple grippers would wrap around the surface of the viruses. This blocked the viral spike proteins from interacting with receptors on the cells’ surface, stopping infection.
“It could be very difficult to use it after an individual is infected, but there is a way we could use it as a preventive therapeutic,” Wang said. “We could make an anti-viral nasal spray compound. The nose is the new spot for respiratory viruses, like COVID or influenza. A nasal spray with the NanoGripper could prevent inhaled viruses from interacting with the cells within the nose.”
The NanoGripper could easily be engineered to focus on other viruses, resembling influenza, HIV or hepatitis B, Wang said. As well as, Wang envisions using the NaoGripper for targeted drug delivery. For instance, the fingers may very well be programmed to discover specific cancer markers, and grippers could carry cancer-fighting treatments on to the goal cells.
“This approach has greater potential than the few examples we demonstrated on this work,” Wang said. “There are some adjustments we’d should make with the 3D structure, the steadiness and the targeting aptamers or nanobodies, but we have developed several techniques to do that within the lab. After all it will require numerous testing, however the potential applications for cancer treatment and the sensitivity achieved for diagnostic applications showcase the ability of soppy nanorobotics.”
The National Institutes of Health and the National Science Foundation supported this work. Wang and Cunningham are affiliated with the Carl R. Woese Institute for Genomic Biology and the Holonyak Micro and Nanotechnology Lab on the U. of I.
Editor’s note: To achieve Xing Wang, email @illinois.edu” title=”mailto:xingw@illinois.edu”>xingw@illinois.edu.
The paper “Bioinspired designer DNA NanoGripper for virus sensing and potential inhibition” is out there from @aaas.org” title=”mailto:robopak@aaas.org”>robopak@aaas.org. DOI: 10.1126/scirobotic
This work was supported partially by NIH grants R21EB031310, R44DE030852 and R21AI166898.
