Tubes, visible in light green, are roughly seven nanometers in diameter — about two million times smaller than an ant — and several microns long, or about the length of a dust particle. Credit: Johns Hopkins University
Key Points:
- Researchers at Johns Hopkins University used DNA fragments to create watertight nanotubes that can transport drugs to single cells.
- The nanotubes are microscopic, and just a million times thinner than a single strand of hair.
- The researchers flushed a fluorescent molecule solution through the nanotubes to test how watertight they are.
Thanks to an ambitious effort by researchers at Johns Hopkins University, doctors may soon possess a tool that would allow them to target specialized areas in their patients’ bodies. The research team, who published their study in Science Advances, created microscopic, leak-free pipes that can be used to administer drugs to areas as tiny as a single cell.
The pipes—or nanotubes—are a million times thinner than a strand of human hair, and were designed to self-repair and attach themselves to various biostructures. The researchers achieved this by building the nanotubes with DNA fragments that encourage them to regenerate and search for structures to connect to.
“This study suggests very strongly that it's feasible to build nanotubes that don’t leak using these easy techniques for self-assembly, where we mix molecules in a solution and just let them form the structure we want,” said Rebecca Schulman, who co-led the study. “In our case, we can also attach these tubes to different endpoints to form something like plumbing.”
DNA strands are interlaced between double helices to produce the nanotubes that are just seven nanometers wide and several microns in length. Up until now, researchers had not been able to observe some of the nanotubes’ physical properties due to their microscopic size.
It was unclear, for example, if the nanotubes could efficiently pass along molecules over long distances, whether or not they were watertight, or if small molecules could wedge through apertures in their walls.
The Johns Hopkins researchers solved this problem by capping the ends of the nanotubes with what they call DNA “corks,” and then flushing a fluorescent molecule solution through them. This provided the team with an opportunity to check for leaks, and allowed them to study the rates at which the solution flowed through the nanotubes.
In the future, researchers may be able to use the nanotubes to learn more about how neurons communicate. The team is also optimistic that their findings can impact epidemiology by allowing researchers to further investigate diseases like cancer.