Scientists at Emory University have developed a nanomaterial that can alter its geometry from flat sheets to tubes and back to sheets with near perfect control. Their results are published in the Journal of the American Chemical Society. The research effort was a collaboration between Emory and scientists from the Argonne National Laboratory, the Paul Scherrer Institute in Villigen, Switzerland, and the Center for Cellular Imaging and NanoAnalytics at the University of Basel.
The nanomaterial is developed to form sheets that our 10,000 times thinner than human hair and is comprised of synthetic collagen. Due to the prevalence of collagen in the body, the novel material is very biocompatible. This biocompatibility opens up the potential applications of this nanomaterial to include drug delivery systems and bioengineering.
"No one has previously made collagen with the shape-shifting properties of our nanomaterial," says Vincent Conticello, professor of biomolecular chemistry at Emory and senior author. "We can convert it from sheets to tubes and back simply by varying the pH, or acid concentration, in its environment."
"As far back as 30 years ago, it became possible to control the sequence of collagen," Conticello says. "The field has really picked up steam, however, during the past 15 years due to advances in crystallography and electron microscopy, which allows us to better analyze structures at the nano-scale."
The collagen protein is made up of a triple helix of fibers that wrap around one. The strands are stiff and they pack together tightly in a crystalline array.
"It's particularly interesting that the condition around which the transition occurs is a physiological condition," Conticello says. "That opens the potential to find a way to load a therapeutic into a collagen tube under controlled, laboratory conditions. The collagen tube could then be tuned to unfurl and release the drug molecules it contains after it enters the pH environment of a human cell."
Image Credit: Conticello Lab