Forget for a moment the classic image of a robot. No more metal arms, gears and circuits. The future of micro-robotics is built with the power of DNA. This is the starting point of the NanoGripper, a programmable structure of nucleic acids that self-assembles into a “miniature hand” complete with four fingers and a palm. A “molecular origami”, but with a very specific purpose: to grab lethal viruses like SARS-CoV-2 and block them before they infect cells; or to deliver drugs in an ultra-precise way by recognizing specific markers on tumors. Let's see together how this nanoscale engineering development works and why it can revolutionize the medicine of the future.
NanoGripper, a (very) miniature hand made of DNA
Do you know the game of origami? Here, imagine being able to fold a single, very long DNA molecule to obtain a programmable 3D shape. This is exactly what researchers at the University of Illinois led by Professor did. Xing Wang. I link the research here, very interesting, published in Science Robotics.
The result is the NanoGripper: a structure a few nanometers (millionths of a millimeter) in size that resembles a hand with four articulated fingers and a palm. The “secret” is all in the design of the DNA, which is folded back and forth like the page of a book to create both the static and moving parts, in a single step.
Catching viruses with your bare hands
Ok, but what is such a small “hand” for? Simple: to catch virus, just like your hand would with an object. The NanoGripper's fingers, in fact, contain specific DNA sequences called aptamers, programmed to bind like molecular Velcro to specific targets. In the case of the SARS-CoV-2 coronavirus, these “Velcros” recognize the spike protein, the sort of crown that allows the virus to attach to cells. Once the target is hooked, the fingers bend to wrap the virus in a vice.
Practical applications: rapid testing and blocking infections
Capturing viruses with your bare hands is spectacular, but what is it really for? Well, there are many uses. For starters, it allows you to detect the presence of the pathogen super rapidly and sensitively. Researchers they have in fact coupled the NanoGripper to a photonic sensor: when the virus ends up in the “hand”, it triggers the release of fluorescent molecules that make it shine like a firefly. Result: a COVID test which in just 30 minutes reaches the same sensitivity as the molecular swabs used in hospital.
But that's not all. The NanoGripper can also completely block the entry of viruses into cells, effectively preventing infection. Test tube tests showed that, when placed in contact with cells and then exposed to the coronavirus, the NanoGrippers They surround the viral surface, preventing the spike protein from interacting with cellular receptors.
Of course, once infected it would be difficult to use this technology as a cure. But in the future it could open the doors to antiviral nasal sprays based on NanoGripper. After all, the nose is the main “gateway” for respiratory viruses like influenza and COVID, right?
NanoGripper, a nano-postman for anti-cancer drugs
The potential of the NanoGripper goes far beyond viruses. With a few changes to the DNA “code,” you can create fingers that recognize specific markers on tumor cells. This opens the door to a super-targeted delivery of anti-cancer drugs, bringing chemo or other therapies only where they are needed and sparing healthy tissue. An incredible prospect.
We are only at the beginning
Let's be clear: the road to bring the NanoGripper from the test tube to the patient's bed is still long. Many tests and improvements are needed, for example to make it more stable in the biological environment and capable of carrying an adequate pharmacological "load".
We are witnessing the eve of the soft nanorobotics, made of biological molecules, which will have many surprises in store for us. After all, nature itself teaches us that rigid and cumbersome mechanisms are not needed to obtain extraordinary functions. Just look at the complexity of our cells, they themselves are real nanorobots that work incessantly to make us function. Biological inspiration, combined with the programmability of synthetic DNA, promises to open a new era for precision medicine in which tiny "hands" or other molecular devices will be able to detect threats or deliver treatments exactly where needed, making diagnoses and therapies much more precise and effective.
Medicine has a great future, because it will be small. Very, very small.
