We are one step closer to the impossible, it seems!
Researchers at Johns Hopkins University have determined that a system of tiny pipes could possibly deliver medicine straight to individual cells. The team says the “nanochannel plumbing system” could one day funnel drugs, proteins, and molecules to precisely targeted organs and tissues without risk of side effects.
This nanochannel system consists of microscopic tubes that self-assemble and can connect themselves to different biostructures.
What’s more, the study authors engineered a way to ensure that the microscopic pipes are invulnerable to leaks.
“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,” says Rebecca Schulman, an associate professor of chemical and biomolecular engineering at Johns Hopkins in a university release. “In our case, we can also attach these tubes to different endpoints to form something like plumbing.”
It’s a significant step toward creating the first network of its kind to combat a host of life-threatening diseases! If this continues to work the way researchers are hoping it will, a medicine with significant complications (like chemotherapy) could be sent to a specific organ or tissue rather than having to pass through the entire body!
The team worked with tubes two million times smaller than an ant and a million times thinner than a human hair, only a few microns long — equivalent to a particle of dust!
They grew and repaired them, enabling them to seek out and connect to specific cells. It is similar to an established method that repurposes DNA as building blocks. They make “nanopores” to control the transport of chemicals across lab-grown lipids that mimic a cell’s membrane.
But, the short fittings alone can’t reach other tubes. The bio-inspired technology described in the Science Advances journal addresses these problems.
“Building a long tube from a pore could allow molecules not only to cross the pore of a membrane that held the molecules inside a chamber or cell but also to direct where those molecules go after leaving the cell,” Schulman says. “We were able to build tubes extending from pores much longer than those that had been built before that could bring the transport of molecules along nanotube ‘highways’ close to reality.”
The nanotubes form using DNA strands woven between different double helices. Think of the “Chinese finger trap” toy.
However, due to the microscopic dimensions, the researchers haven’t been able to test whether or not they could transport molecules for longer distances without leaking or slipping through gaps in the “wall.”
But, doctoral graduate and co-lead author Yi Li, capped the end of a pipe with special DNA “corks” and turned on a faucet to make sure no water leaked out. Li then ran a solution of fluorescent molecules to track leaks and influx rates. The glowing molecules slid through like water down a chute.
“Now we can call this more of a plumbing system, because we’re directing the flow of certain materials or molecules across much longer distances using these channels,” Li explains. “We are able to control when to stop this flow using another DNA structure that very specifically binds to those channels to stop this transport, working as a valve or a plug.”
DNA nanotubes could help scientists better understand how neurons interact with one another. Researchers could also use them to study diseases like cancer and the functions of the body’s more than 200 types of cells.
Next, the team plans to conduct additional studies with synthetic and real cells and different types of molecules.