Team builds effective antibodies from plastic

Posted by Emma Woollacott

UC Irvine researchers have created the first 'plastic antibodies' and  successfully tested them in mice.

Tiny polymeric particles were designed to block bee venom by matching and encasing melittin, a peptide in bee venom that causes cells to rupture. Large quantities of melittin can lead to organ failure and death.

The polymer nanoparticles were prepared by molecular imprinting, a technique similar to plaster casting. The team linked melittin with small molecules called monomers, solidifying the two into a network of long polymer chains.

After the plastic hardened, they removed the melittin, leaving nanoparticles with minuscule melittin-shaped holes.

When injected into mice which had been given high doses of melittin, these precisely imprinted nanoparticles enveloped the matching melittin molecules before they could disperse, greatly reducing deaths among the mice.

"Never before have synthetic antibodies been shown to effectively function in the bloodstream of living animals," says UCI chemistry professor Kenneth Shea. "This technique could be utilized to make plastic nanoparticles designed to fight more lethal toxins and pathogens."

Unlike natural antibodies produced by live organisms and harvested for medical use, synthetic antibodies can be created in laboratories at a lower cost and have a longer shelf life.

"The bloodstream includes a sea of competing molecules – such as proteins, peptides and cells – and presents considerable challenges for the design of nanoparticles,” Shea says. “The success of this experiment demonstrates that these challenges can be overcome."