Massachusetts Institute of Technology researchers said they discovered gold nanoparticles coated with alternating bands of two different kinds of molecules can quickly pass into cells without harming them, while those randomly coated with the same materials cannot.

"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," said Associate Professor Francesco Stellacci, co-leader of the study with Professor Darrell Irvine.

"No one understands how these biologically derived cell-penetrating materials work," said Irvine. "So we could use the new particles to learn more about their biological counterparts. Could they be analogues of the biological system?"

The research was reported in an advance online publication of the journal Nature Materials.