Plastic antibodies are able to fight antigens in the body like real antibodies

A group of researchers from the University of California at Irvine together with researchers from the University of Shizuoka from Japan made a huge breakthrough in the field of plastics. The group found a use for plastic at the microscopic level and even at the nanoscopic level. The researchers showed that if we use nanoparticles of the order of 50,000/XNUMXth the width of a human hair, it is possible to create "plastic antibodies"

We use plastic to make everything from plastic bags, containers, appliances and almost every product in the home. However, a group of researchers from the University of California at Irvine together with researchers from the University of Shizuoka from Japan made a huge breakthrough in the field of plastics. The group found a use for plastic at the microscopic level and even at the nanoscopic level. The researchers showed that if we use nanoparticles of the order of 50,000 times the width of a human hair, it is possible to create "plastic antibodies" (that is, simple and synthetic organic PNP polymer nanoparticles the size of a protein). The plastic antibodies function successfully in the bloodstream of living animals, when they manage to recognize and fight a variety of antigens (proteins identified as foreign substances by the immune system, which produces antibodies to fight them).

First of all, antibodies are the proteins in our body that are created by the immune system to distinguish and neutralize foreign threats, such as infections, allergens, viruses and bacteria. These can sometimes just be annoying and harmless things like pollen and dust particles or allergens from foods and even the other toxins that are less pleasant and sometimes dangerous. Our body produces antibodies in considerable quantities. Sometimes it is not possible to deal with certain antigens. Like for example, a severe infection - our natural antigens simply give up.

To deal with this deficiency of the immune system, the researchers took tiny plastic nanoparticles and decided to create antibodies from them. The following problem arises when synthetic substances are injected into a biological environment: if we inject foreign substances such as the polymeric nanoparticles PNP into the bloodstream, a layer of proteins is immediately formed on the surface, and these can change, or even suppress, the immune response to the foreign substance.

Therefore, the researchers first decided to test and demonstrate the ability of the PNP outside the living body and thus try and imitate natural antibodies. That is, they first and foremost decided to test the biocompatibility of the PNP, the reaction of the biological tissues to the PNP. Then they decided to use the melittin antigen, a peptide that is one of the main components of bee venom. It has been found to be non-toxic in cultured cells in the laboratory in small amounts. Then, the researchers injected a small amount of the substance into a vein directly into the bloodstream of lab mice. For two weeks there was no difference in the weight of the mice that received the melittin. In addition, no signs of poison or signs of allergy were found. In high doses, melittin causes cell destruction in the animal, a process that ends in death due to kidney failure or cardiological complications.

The researchers then used a process known as molecular imprinting to imprint the shape of the hemelitin antigen onto the PNP antibody. By embedding tiny melittin-shaped niches into the individual particles, plastic antibodies, the researchers finally tuned the plastic antibodies to attach themselves to the melittin antigens in the blood.

The researchers injected into the vein of the mice that received the lethal amounts of hemelitin by injection plastic antibodies of two types: 1) there were mice that received PNP with the shape of the hemelitin antigen imprinted on it and 2) there were other mice that received PNP of the exact same composition but they were synthesized so that they did not apply the imprint of hemelitin. In addition to this group of mice, there was a control group.

In this last group, a 100% death rate was observed in the mice that received melittin in high amounts. The mice that received the plastic antibodies imprinted with the shape of the melittin antigen survived at a much higher rate than those who received plastic antibodies without the melittin imprint. And this led to the conclusion that, while the PNPs are found in the bloodstream, the PNPs embedded with melittin noticed the melittin poison and neutralized its activity. Therefore, the study concluded that well-targeted plastic antibodies can indeed follow the antigen and destroy threats inside a living body.

The success of the molecular imprinting procedure, along with the high survival rate of the mice that received the plastic antibodies, suggested that researchers could design a variety of such plastic nanoparticles for use whenever the body relies on antibodies to fight threats. This opens the door to a powerful synthetic immune booster that could potentially be used to treat a myriad of allergies, diseases and infections.