Scientists at the University of Massachusetts Amherst have discovered that, when placed inside a charged water-based gel, DNA molecules may stay in place rather than diffusing. The findings could be a breakthrough in several biomedical areas, including gene therapy.
The study, conducted by UMass Amherst polymer scientists Di Jia and professor Murugappan Muthukumar, was published in the journal Nature Communications on Friday.
Researchers placed large, negatively charged DNA molecules in a mesh-form gel with the same charge made of 96 percent water, according to a statement from UMass Amherst. They expected the molecules to move slowly but eventually diffuse. Instead, they found that using the specially-designed gel to capture the DNA, they would not diffuse at all.
Imagine a molecule trapped in cubic mesh with roughly equal-sized compartments. For the molecule to diffuse, one of the compartments has to try to move, but then drag all other compartments with it. The molecule will become “frustrated,” and get stuck in place, according to the statement.
Jia experimented with both synthetic and natural molecules in the gel, and found that both exhibited the same phenomenon.
Muthukumar says this goes against what scientists previously believed about diffusion of polymers in water-based substances.
“The DNA is not anchored because of any chemical bond,” he said. “We are able to manipulate the gel in such a way so there is no chemical interaction between the gel and the DNA.”
Muthukumar said this could have implications for gene therapy, used to replace mutated genes or fight diseases, because the gel traps DNA complexes in place, which could help scientists direct it to places in the body and keep it there.
“We want to keep them for a long time so they can keep on exhibiting their relief properties,” he said.
Additionally, Muthukumar says, the findings may reveal information about a phenomenon that already exists in the natural world that we were previously unaware of.
“The crowded environments in biological systems are acting like a gel and are creating these correlated barriers for different parts of the [polymer] chains to move,” he said. “Biology might be harnessing this feature and we’re just now appreciating it.”Laney Ruckstuhl can be reached at email@example.com. Follow her on Twitter @laneyruckstuhl.