A new advancement in nanotechnology has emerged from the University of Illinois Urbana-Champaign: a remarkable four-fingered “hand” intricately crafted from a single strand of DNA. This innovative NanoGripper is designed to detect the COVID-19 virus with exceptional sensitivity and even prevent viral particles from infiltrating human cells to cause infection.
Researchers envision this nanorobotic marvel being programmable to interact with various viruses and identify specific cell surface markers, paving the way for targeted drug delivery, particularly in cancer therapies. Under the leadership of Xing Wang, a prominent professor in bioengineering and chemistry, these findings are now detailed in the prestigious journal Science Robotics.
Drawing inspiration from the extraordinary, gripping abilities of human hands and bird claws, the NanoGripper features four flexible fingers and a palm, all integrated into a single, sophisticated nanostructure.
Each finger possesses three joints, mimicking human anatomy, with the design on the DNA scaffold meticulously determining the angle and flexibility of each joint. This innovative design holds immense potential for transformative applications in medicine and beyond.
“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,” Wang said. “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.”
The NanoGripper features innovative fingers embedded with DNA aptamers, meticulously engineered to bind to specific molecular targets—specifically, the spike protein of the virus responsible for COVID-19. When these aptamers connect with the target, they prompt the fingers to flex and encase the molecule securely.
On the other end, where the wrist would normally be, the NanoGripper can secure itself to a surface or a larger structure for biomedical uses like sensing or drug administration. In order to develop a virus detection sensor for COVID-19, Wang’s team collaborated with a group led by Professor Brian Cunningham from Illinois, who is an expert in biosensing technologies.
By combining the NanoGripper with a cutting-edge photonic crystal sensor platform, they have produced a rapid COVID-19 test that delivers results in just 30 minutes. This test matches the sensitivity of the gold-standard qPCR molecular tests utilized in hospitals, which are known for their high accuracy but require significantly more time than this innovative solution.
“Our test is very fast and simple since we detect the intact virus directly,” Cunningham said. “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.”
The NanoGripper has the potential to revolutionize preventive medicine by effectively blocking viruses from entering and infecting cells, as highlighted by Wang. The researchers discovered that when NanoGrippers were introduced to cell cultures exposed to COVID-19, several grippers would encircle the viruses, hindering the viral spike proteins from interacting with the receptors on the surface of cells and preventing infection.
“It would be very difficult to apply it after a person is infected, but there’s 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 hot spot for respiratory viruses like COVID-19 or influenza. A nasal spray with the NanoGripper could prevent inhaled viruses from interacting with the cells in the nose.”
Wang also mentioned that the NanoGripper could easily be tailored to target additional viruses, including influenza, HIV, or hepatitis B. Moreover, Wang imagines employing the NanoGripper for precise drug delivery. For instance, the fingers could be programmed to detect specific cancer markers, enabling grippers to transport cancer-fighting medications directly to the designated cells.
“This approach has bigger potential than the few examples we demonstrated in this work,” Wang said. “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.”
Journal reference:
- Lifeng Zhou, Yanyu Xiong, Abhisek Dwivedy, Mengxi Zheng, Laura Cooper, Skye Shepherd, Tingjie Song, Wei Hong, Linh T. P. Le, Xin Chen, Saurabh Umrao, Lijun Rong, Tong Wang, Brian T. Cunningham, Xing Wang. Bioinspired designer DNA NanoGripper for virus sensing and potential inhibition. Science Robotics, 2024; DOI: 10.1126/scirobotics.adi2084
