Shea says that better synthetic antibodies could be used therapeutically in parts of the body where normal antibodies break down quickly, such as the digestive tract. They could also be used in portable devices designed to detect traces of chemical weapons.
The new method for making the artificial antibodies is “a dramatic breakthrough,” says Ken Shimizu, a chemist at the University of South Carolina. “People always say their polymers work a lot like antibodies, but in truth, they never did.” He adds that Shea’s work comes close to living up to this promise. “This is the first time you could imagine these [synthetics] would rival antibodies.”
David Spivak, a chemistry professor at Louisiana State University, agrees that Shea’s work is “the first example of an imprinted polymer acting like an antibody.” Spivak expects that Shea’s method will work with other target molecules, including proteins besides melittin. Indeed, Shea says that he is working on targeting about five more complex proteins.
However, some chemists are skeptical that Shea’s artificial protein is targeting melittin like a real antibody. They suggest that melittin, which has positively charged regions, may simply be attracted to negative charge on the polymer. But Shea says he selected polymer building blocks based on their ability to bind regions of melittin, and that he has performed controlled experiments to demonstrate that the binding is indeed specific. Further, he says that he has unpublished work showing that his polymer binds to melittin in cell cultures and in small animals, suppressing its toxic activity.