Nanoparticles that can penetrate a cell without harming its membrane have been developed by engineers at the Massachusetts Institute of Technology (MIT).
The researchers say that their work attains significance as it raises the hope of realising drug delivery systems based on nanoparticles.
They have revealed that gold nanoparticles coated with alternating bands of two different kinds of molecules were found to have the ability of quickly pass into cells without poking a hole in their protective membranes.
"We've created the first fully synthetic material that can pass through a cell membrane without rupturing it, and we've found that order on the nanometer scale is necessary to provide this property," Nature Materials quoted Francesco Stellacci, an associate professor in the Department of Materials Science and Engineering, as saying.
The researchers tested the practical applications of the nanoparticles for drug delivery by using them to deliver fluorescent imaging agents to cells.
Apart from such applications, the team adds, the tiny spheres might also help study what enables some biological materials like peptides to enter cells.
"No one understands how these biologically derived cell-penetrating materials work. So we could use the new particles to learn more about their biological counterparts. Could they be analogues of the biological system?" said the study's co-author Darrell Irvine, the Eugene Bell Career Development Associate Professor of Tissue Engineering.
He says that the feat is quite similar to a phenomenon kids can discover.
"If you have a soap film and you poke it with a bubble wand, you'll pop it. But if you coat the bubble wand with soap before poking the film, it will pass through the film without popping it because it's coated with the same material," he said.
According to Stellacci, the coated nanoparticles have properties similar to the cell membrane, not identical, but the analogy is still apt.
Stellacci, who first reported the creation of the striped nanoparticles in a 2004 Nature Materials paper, said: "(At the time), we noticed that they interacted with proteins in an interesting way."
"Could they also have interesting interactions with cells?" was the question they had yet to determine at the time.
The researcher now says that he and his colleagues have found the answer to that question in the affirmative.