Chemists have developed a nanomaterial that can change shape. Now scientists are testing its properties.
A leaf-shaped nanomaterial 10,000 times thinner than human hair was made from synthetic collagen. Naturally, occurring collagen is the most abundant protein in the human body, so the new material is also biologically compatible.
No one has ever created collagen that can change shape. We can turn it from leaf to test tube and vice versa by simply changing the pH or acid concentration in the environment.
Name Vincent Conticello, Senior Discovery Author and Emory Professor of Biomolecular Chemistry
Collagen protein consists of a triple helix of fibers that twine around each other like a three-strand rope. The strands are not flexible, they are tough like pencils and fold tightly into a crystalline array.
The leaf is one large two-dimensional crystal, but due to the packaging format of the peptides, it looks like a bunch of pencils. Half of the pencils in the bundle have their ends pointing upward, while the other half is the opposite.
Conticello wanted to refine the collagen sheets so that each side was limited to one function. By analogy with pencils: one surface of the sheet will have all the tips, and the other will have erasers.
So the researchers were able to tune the sheets to change shape at specific pH levels, in a way that could be manipulated at the molecular level by design.
Such properties can be used, for example, in medicine, where a patient needs to load a therapeutic agent into a collagen tube, and then the tube can be uncoupled into molecules that contain the drug.