"We can make collagen that duplicates nature exactly, but we can diverge from that when it is desirable," says Ronald T. Raines, a UW-Madison professor of biochemistry who, with postdoctoral fellow Frank W. Kotch, authored the new PNAS study.
Scientists have been seeking a way to make synthetic collagen for at least 30 years. In clinical settings, human collagen would be preferred over bovine collagen because the material now gleaned from cows can prompt an unwanted immune response in patients and it can harbor animal pathogens that might infect humans.
The Wisconsin team discovered a way to make the long, slender collagen molecules, in essence, by having the protein assemble itself. What was required, Raines explains, was a way to give the collagen snippets that scientists could easily make a way to "self assemble" into the long, thin fibers of native collagen. The Wisconsin team was able to modify the ends of the snippets so they could fit together and stick to form long collagen fibers.
"Now we can make synthetic collagen that's longer than natural collagen," says Raines, who previously authored a paper in the journal Nature that demonstrated how to make synthetic collagen that is stronger than natural collagen. "We just don't have to take what nature gives us. We can make it longer and stronger."
In medicine, synthetic human collagen could be used as "solder" to speed healing of large wounds. In the context of nanotechnology, collagen has appeal as a type of nanowire because it is thin -- thinner even than the vaunted carbon nanotubes hailed by nanotechnologists -- and long.
Coated with gold or silver, human collagen could form the basis of implantable electric sensors. By attaching certain biological molecules to the wire, it would be possible to create sensors that might, for example, quickly alert a diabetic to falling insulin levels.
Source:University of Wisconsin-Madison