Researchers in Japan and California (Stanford, UC Irvine) have developed plastic antibodies capable of seizing and neutralizing dangerous materials in the body. The polymer nanoparticles were injected into live mice after they had been subjected to melittin, the toxin in bee venom. The nanoparticles captured the melittin and carried it to the liver for destruction. As reported in the Journal of the American Chemical Society, nearly 60% of mice treated with the plastic antibodies survived compared to 0% of mice who were injected with just bee venom. I was able to talk briefly with Professor Kenneth Shea at UC Irvine about the experiment and this is the first time such techniques have been used in living animals. The plastic antibodies could eventually be shaped to capture many different antigens including viruses and proteins. In my view, these polymer nanoparticles may be the first step in building an artificial immune system in humans to augment our natural one.
Regenerative medicine may have the potential to regrow organs, or even fight the effects of aging, but it’s nanotechnology that holds truly mind-blowing promise for our bodies. We’ve already seen how Dendreon (with Provenge) has essentially turned the human immune system into a nanotechnology by training it to fight prostate cancer. Now the researchers in the plastic antibody project are providing an artificial expansion of the immune system. While the body naturally forms antibodies to many toxins, the polymer nanoparticle approach let’s us develop synthetic antibodies before we are ever exposed to a substance. Almost any molecule has the potential to be targeted by these plastic antibodies, letting us augment our immune systems for almost any toxic situation. Eventually, this nanotechnology will be joined by others that augment the way we deliver oxygen and food to our cells, regulate our temperatures, and repair damaged tissue. Nanotechnology may one day provide our bodies with unbelievable resilience and longevity.
Yet the plastic antibodies created at UC Irvine are still relatively simple forms of nanotech. In fact, you can think of them as plastic molds. Monomer particles and the melittin toxin were mixed together and the monomers formed a sort of cast around the toxin. The toxin was then removed through dialysis, leaving empty cavities where it once resided. This process, called molecular imprinting (MIP), produces the polymer nanoparticles that have exactly crafted holes for the toxin they were designed to capture. This allows these plastic antibodies to bond to those toxins (such as melittin) but not otherwise interfere with the body.
The research team tested the biocompatibility for the plastic antibodies by exposing them to mice cells in vitro. When that proved successful, they proceeded to test the nanoparticles in live mice. Two weeks after injection the mice hadn’t lost weight and maintained healthy tissues, demonstrating that the plastic antibodies were non-toxic (at least in the short term).
Once the polymer nanoparticles were deemed safe for trial, researchers proceeded to test their efficacy. As mentioned above, mice were injected with bee venom (melittin), the toxin for which the batch of plastic antibodies have been molecularly imprinted. 20 seconds later, mice received either the imprinted antibodies, non-molecularly imprinted antibodies, or nothing. The size of each group was about 30, and several rounds of testing occurred. Mice who received nothing always died (now I know who to bet on in a bee vs. mouse battle). Molecularly imprinted nanoparticles allowed nearly 60% of injected mice to survive. That’s pretty good evidence that the plastic antibodies are doing their job well.