June 9, 2010 | 4
A sting from a tiny bee triggers a long chain of events. In addition to promoting inflammation and inhibiting coagulation, the molecular hodge-podge that is bee venom can actually cause cells to split open. The toxin responsible for this effect is melittin, and in high enough concentrations, it can be deadly.
When toxins, bacteria and viruses enter the body, they’re eventually met by antibodies uniquely designed to recognize and remove intruders. At least they should be. In some instances antibodies are produced slowly or not at all, leaving foreign invaders free to circulate in the blood unchecked, spreading infection and leaving host cells open to attack.
But scientists may have come up with a solution: plastic antibodies—artificial versions of the lymphocyte-produced proteins—that work just like the real thing. In collaboration with researchers at the University of Shizuoka, Japan, and Stanford University, Yu Hoshino and Kenneth Shea from the University of California, Irvine, made plastic nanoparticles, barely one fifty-thousandth the width of a human hair, that latch onto antigens (molecular flags on foreign invaders) like natural antibodies.
Using molecular imprinting—a process akin to leaving a footprint in wet cement—the researchers created melittin-shaped craters in tiny plastic dots. When injected into mice after a lethal dose of melittin, the plastic antibodies diminished melittin’s toxic effects and enhanced survival. "These results establish for thefirst time that a simple, nonbiological synthetic nanoparticle with antibodylike affinity and selectivity (that is, a plastic antibody) can effectively function in the bloodstream of living animals," the researchers wrote in their report published online April 26 in the Journal of the American Chemical Society.
"This opens the door to serious consideration for these nanoparticles in all applications where antibodies are used," Shea said in a prepared statement, suggesting the technique could be used to generate plastic antibodies tailored to fight any number of troublesome antigens.
Photo of plastic antibodies courtesy of Kenneth Shea