Reviewed by Danielle Ellis, B.Sc.Nov 28 2024
Researchers from the University of Illinois Urbana-Champaign developed a small, four-fingered “hand” made from a single piece of DNA that can identify the COVID-19 virus with high sensitivity and speed and even prevent viral particles from infecting cells. The research was published in the journal Science Robotics.
An artistic rendering of the NanoGripper’s applications. Sites on the gripper’s fingers recognize the spike protein of a virus, inset, and trigger fluorescent tags to emit light. When coupled with a sensor, individual viruses can be detected for a rapid COVID test, foreground. Alternately, the NanoGrippers can block viruses from entering cells by wrapping around the spike proteins, top right. Image Credit: University of Illinois Urbana-Champaign
Named NanoGripper, this nanorobotic hand can also be programmed to interact with other viruses or identify cell surface markers, enabling precise applications like targeted drug delivery for cancer treatment.
Xing Wang, a Professor of Chemistry and Bioengineering at the University of Indiana, guided the research team.
The researchers created the NanoGripper, a nanostructure made from a single piece of DNA that has four pliable fingers and a palm based on the gripping ability of the human hand and avian claws. Like a human finger, each finger has three joints, and the DNA scaffold's architecture dictates the degree and angle of bending.
We wanted 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. We are using DNA for its structural properties. It is strong, flexible, and programmable. Yet even in the DNA origami field, this is novel in terms of the design principle. We fold one long strand of DNA back and forth to make all of the elements, both the static and moving pieces, in one step.
Xing Wang, Professor, Chemistry and Bioengineering, University of Indiana
Certain parts of the fingers, known as DNA aptamers, are specifically designed to attach to molecular targets, in this case, the spike protein of the COVID-19 virus, and induce the fingers to flex to encircle the target. For biomedical uses like medication distribution or sensing, the NanoGripper can be affixed to a surface or other bigger complex on the opposite side, where the wrist would be.
Wang's team collaborated with a team headed by Brian Cunningham, a biosensing expert and Professor of Electrical and Computer Engineering at Illinois, to develop a sensor to identify the COVID-19 virus.
To develop a quick, 30-minute COVID-19 test that matches the sensitivity of hospital-use gold-standard qPCR molecular tests, which are more accurate than at-home tests but require a lot more time, they combined the NanoGripper with a photonic crystal sensor platform.
Our test is very fast and simple since we detect the intact virus directly. When the virus is held in the NanoGripper’s hand, a fluorescent molecule is triggered to release light when illuminated by an LED or laser. When a large number of fluorescent molecules are concentrated upon a single virus, it becomes bright enough in our detection system to count each virus individually.
Brian Cunningham, Professor, Electrical and Computer Engineering, University of Illinois Urbana-Champaign
By preventing viruses from entering and infecting cells, the NanoGripper may find value in preventative medicine in addition to diagnostics, Wang added. Multiple grippers would encircle the outside of the viruses when NanoGrippers were introduced to cell cultures that were subsequently exposed to COVID-19, the researchers discovered. This prevented infection by blocking the viral spike proteins from engaging with cell surface receptors.
It would be very difficult to apply it after a person is infected, but there is a way we could use it as a preventive therapeutic. We could make an anti-viral nasal spray compound. The nose is the hot spot for respiratory viruses, like COVID or influenza. A nasal spray with the NanoGripper could prevent inhaled viruses from interacting with the cells in the nose.
Xing Wang, Professor, Chemistry and Bioengineering, University of Indiana
According to Wang, it would be simple to modify the NanoGripper to target additional viruses like hepatitis B, HIV, or influenza. Wang also sees the NaoGripper being used for targeted medicine delivery. For instance, grippers may deliver cancer-fighting medications straight to the target cells, and fingers could be programmed to recognize particular cancer indicators.
Wang said, “This approach has bigger potential than the few examples we demonstrated in this work. There are some adjustments we would have to make with the 3D structure, the stability, and the targeting aptamers or nanobodies, but we have 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.”
The National Institutes of Health and National Science Foundation funded this work. Wang and Cunningham have affiliations with the Holonyak Micro and Nanotechnology Lab at the Carl R. Woese Institute for Genomic Biology and the University of I.J.
Journal Reference:
Zhou, L., et al. (2024) Bioinspired designer DNA NanoGripper for virus sensing and potential inhibition. Science Robotics. doi.org/10.1126/scirobotics.adi2084.