The experiments showed that a single nanoparticle is able to very quickly accelerate the neutralization of thousands of active oxygen molecules that are harmful to the body and that are expressed more by the body's cells in response to injury while converting them to neutral oxygen
![Hydrophilic carbon aggregate together with polyethylene glycol developed at Rice University has the potential to moderate the overexpression of harmful superoxides through the conversion of active oxygen species that may harm biological functions into neutral oxygen molecules. [Courtesy of Errol Samuel/Rice University]](https://www.hayadan.org.il/images/content3/2015/02/0216_HCC-1-WEB-465x500.jpg)
[Translation by Dr. Nachmani Moshe]
Injected nanoparticles, the kind that could protect an injured person from further damage following oxidative stress, have been shown to be extremely effective in trials.
Scientists from Rice University and the University of Texas have developed methods to validate their 2012 discovery that combined polyethylene glycol with hydrophilic carbon aggregates, known as PEG-HCCs, a discovery that inhibits the process of over-oxidation that can cause damage in the immediate minutes and hours after injury.
The experiments showed that a single nanoparticle is able to very quickly accelerate the neutralization of thousands of active oxygen molecules that are harmful to the body and which are expressed more by the body's cells in response to injury while converting them to neutral oxygen. These active forms can damage cells and cause genetic mutations, but it seems that the new material (PEG-HCCs) has a great ability to convert them into less active and therefore less harmful substances. The researchers hope that injecting the substance as quickly as possible immediately after an injury to the body, such as a traumatic head injury or a stroke, will be able to mitigate the extent of brain damage by restoring oxygen levels to normal levels. The results of the study have long been published in the scientific journal Proceedings of the National Academy of Sciences.
"Practically, the substances restore oxygen levels in the body to normal levels almost immediately," said chemist James Tour. "This mechanism could be a particularly useful tool for emergency medicine personnel who are required to quickly stabilize victims of car accidents or strokes, or to treat severely wounded soldiers on the battlefield."
Materials from the PEG-HCCs group have a width of 3 nanometers, a length of 40-30 nanometers and contain 5000-2000 carbon atoms. In the experiments conducted, a single nanoparticle was able to accelerate the conversion of 20 thousand to a million active oxygen molecules every second into a neutral oxygen molecule, the same molecule consumed by damaged tissues. The same researchers were also responsible for a previous study that demonstrated that an infusion of the innovative substance is able to quickly stabilize blood circulation in the brain and protect it from active oxygen molecules that are more expressed by the cells during medical trauma, especially when it is accompanied by massive blood loss.
Their research focused on traumatic brain injuries, injuries that cause cells to release a large amount of reactive oxygen species known as superoxide. (Wikipedia, Superoxide) into the bloodstream. These toxic free radicals are molecules with a single unpaired electron that the immune system uses to destroy microorganisms that have invaded the body. In low concentrations, these forms contribute to regulating the normal energy consumption of the cells. Normally, they are regulated by the enzyme superoxide dismutase responsible for the neutralization of these forms. However, even mild contusions may release enough superoxides to damage the brain's natural defense mechanisms. As a result, these forms may create even more harmful oxygen forms (peroxynitrite, Wikipedia) causing further serious damage.
"The current study showed that the substance PEG-HCCs acts catalytically, at an extremely fast rate and is capable of neutralizing thousands of harmful molecules, especially superoxygen and hydroxyl radicals that destroy normal tissues when the concentration of radicals in them is particularly high," explained the lead researcher. "This result is important not only for the treatment of traumatic brain injuries and strokes, but also for the treatment of many serious injuries to any organ or tissue as well as for medical procedures such as organ transplantation," explains the researcher. "In any situation where the tissue is exposed to stress, as a result of which the oxygen concentration decreases, the superoxygen radical may cause additional damage to the environment of the healthy tissue."
The researchers used the method of electron paramagnetic resonance spectroscopy (ESR) through which the structure and rate of formation of superoxygen radicals can be directly obtained by counting the unpaired electrons in the presence of the antioxidant PEG-HCC, or in its absence. "In complete contrast to the known enzyme superoxide dismutase, our substance is not a protein and does not contain a metal atom that helps in the catalytic activity," explains the lead researcher. "The particularly efficient catalytic activity of the material may be due to the conjugated and planar carbon core."
