A Plastic Cure

UC Irvine’s scientific research has breached a new frontier. Kenneth Shea, professor of chemistry and chemical engineering and material science, and Yu Hoshino, assistant project scientist studying polymer chemistry, were the first to successfully implement “plastic” antibodies in a living organism to stop the spread of melittin, a principle component of honey bee venom. Melittin is a powerful cell lytic agent and if present in large quantities, it could lead to organ failure and death.

Shea explains that for the purpose of their study, melittin serves as a prototype for a family of toxins that are more seriously life-threatening. Their success with melittin opens the door to developing “plastic” antibodies; specifically ones called imprinted polymer nanoparticles, for more serious toxins.

To create their “plastic” antibodies, the research team used a method known as molecular imprinting.

Shea explains what this entails in more detail.

“The process, known as molecular imprinting, is similar to making a plaster cast: small amounts of the imprinting molecule melittin are added to small functional molecules called monomers. A chemical reaction known as polymerization solidifies the two into a network of long polymer chains. When the plastic (polymer) hardens, the melittin is removed, leaving nanoparticles with tiny melittin-shaped holes or binding sites,” Shea said.

After, the living organisms (more specifically mice) were injected with melittin. The toxin was given time to circulate throughout the mouse before the imprinted polymer nanoparticles were injected. In their experiments, the polymer nanoparticles were able to successfully capture the melittin molecules and prevent the detrimental consequences that result from exposure to the toxin.

While the polymer nanoparticles are not ready for testing in humans, there remains  myriad non-therapeutic applications for these “plastic” antibodies that have greater short term potential.

Shea shares what he hopes people will take away from their finding.

“This is the first time that synthetic antibodies have been shown to effectively function in the bloodstream of living animals. This technique could be utilized to make plastic nanoparticles designed to fight dangerous pathogens. Unlike natural antibodies which are produced by living organisms, synthetic antibodies are produced abiotically in the laboratory, at a lower cost and have a longer shelf life than natural antibodies,” Shea said.

For their research on plastic antibodies, the team received a grant from the National Institute of Health.

Others researchers assisting in the study include Takashi Kodama of Stanford University and Hiroyuki Koide, Takeo Urakami, Hiroaki Kanazawa and Naoto Oku of the University of Shizuoka in Japan.

“We are developing plastic antibodies for more important targets than honey bee venom to cure more serious diseases,” Hoshino said. “Additionally, we are also developing methods to create ‘monoclonal’ plastic antibodies.”