Shea’s plastic antibody targeting melittin performed well in test tubes, but there was still some skepticism whether it would work in the complex environment of the body. This month in Journal of the American Chemical Society, the University of California researchers describe promising studies in mice. The researchers attached different fluorescent imaging probes to melittin and to the plastic antibody, injected them into the mice, and watched what happened in real time. Because the probes were two different colors, the researchers were able to watch as the polymer met its target in vivo, and as the two were then cleared to the liver. In mice given only the toxin and not the antidote, the mice’s symptoms were much worse, and the toxin was more widely distributed throughout the body.
“They show that these materials are biocompatible and really act like antibodies–it’s kind of surprising,” says Ken Shimizu, professor of biochemistry at the University of South Carolina. Researchers had suspected that the body might not recognize the plastic particles as antibodies and thus they would be ineffective, or that they might get gummed up with other particles in the complex mixture that is the bloodstream.
Shea says that he’s been contacted by several pharmaceutical companies that are interested in seeing how the work develops. David Spivak, professor of chemistry at Louisiana State University, agrees that the method is “a general strategy that will work again and again.” “These particles have huge advantages in terms of stability and low cost,” says Spivak. “I just hope this work is reproducible for many different targets.”
The California researchers developed their imprinting methods using melittin because it’s relatively inexpensive and easy to obtain, and it’s a good representative of a class of small protein toxins, some of which are much more deadly. “Our next steps are to pursue more serious toxins,” says Shea.