Interest in silk has been growing within the biomedical engineering community in recent years, thanks to the remarkable properties of silk proteins and fibers. Silk is strong and durable, can be engineered to be non-immunogenic, and is completely resorbable. We have covered several novel applications of silk in medicine previously, including neural electrode interfaces, nerve repair, bioelectronics, and tissue scaffoling.
Most recently, silk has been incorporated into biosensors. Peter Domachuk, a physicist at the University of Sydney, conceived of using silk as a biosensor component while working with Fiorenzo Omenetto and David Kaplan at Tufts University in Boston. In principle, various biochemically reactive proteins may be embedded in silk fibers, which may then be assembled into “bio-chips”. As a proof-of-concept, Dr. Domachuk and his team have successfully created an oxygen sensor by embedding hemoglobin proteins within silk fibers. In the future, the group hopes to embed a broad range of proteins within a single chip, enabling the simultaneous testing of several parameters at the bedside.
More from the University of Sydney press release:
The protein that underpins the strength of silk, fibroin, can be purified to form a clear material that can be used to display tiny drops of thousands of different biochemical compounds in patterns where they are no farther apart than the width of a human hair. These test compounds can then be simultaneously exposed to and react with body fluids such as human blood.
“The particularly interesting thing about silk,” Peter says, “is that the biochemical compounds it holds retain their activity. This biochemical activity enables extra sensitivity for monitoring and detecting medical conditions. And fibroin is transparent and can be formed into structures to control light which can be then used as a sensitive probe for improved medical testing. What’s more, silk doesn’t trigger the human immune response when it comes into contact with tissue.”
The above combination of factors makes silk a unique candidate for implantable biochips – devices like electronic microchips that can sit in or under the skin and detect chemicals in the blood. This can allow quick and accurate determination of medical conditions without the need for expensive laboratory-based pathology.