Scientists synthesize nanoparticle-antioxidants to treat strokes and spinal cord injuries

An international science team has developed an innovative therapeutic complex based on multi-layer polymer nano-structures of superoxide dismutase (SOD). The new substance can be used to effectively rehabilitate patients after acute spinal injuries, strokes, and heart attacks. 

One of the most devastating forms of trauma to the human body is a spinal cord injury, representing a serious clinical problem around the globe. In addition to the direct damage to nerve fibers, subsequent problems like the overproduction of free radicals (active forms of oxygen) and inflammation also pose serious risk.

Spinal cord injuries, strokes and cardiac arrest are caused by impacts, ruptured blood vessels and tissue necrosis. When blood arteries contract or become clogged inside an organ's adjacent tissues, this leads to hypoxia, a pathological process linked with oxygen shortages. This factor blocks the final link of the respiratory chain at the cellular level and creates an excessive number of so-called free radicals or active forms of oxygen. They, in turn, destroy cellular membranes and initiate a sequence of reactions that damage and destroy body cells and tissues. These complications damage the spinal cord still further and kill neurons, making the clinical picture even more complicated.

A special ferment/anti-oxidant called superoxide dismutase (SOD1) acts as an effective agent which naturally absorbs free radicals. If delivered quickly enough to a damaged organ, this substance can mitigate the stressful oxidization process caused by an excessive number of free radicals and hence stop the process of tissues being destructed. However, this ferment remains unstable inside the bloodstream during intravenous injections; it disintegrates quickly and fails to neutralize free radicals on time.

"In order to create a stable therapeutic complex based on the SOD1 substance, we developed catalytically active forms of superoxide dismutase, or nanozymes. For example, we obtained the SOD1 poly-ion complex for the first time in history. This complex features additional poly (amino acid) block co-polymers and PEG/poly-glutamine acid acting as a surface cover," said Maxim Abakumov, project coauthor, Head of NUST MISIS' Biomedical Nanomaterials Laboratory.

This made it possible to obtain a porous polymer capsule measuring between 40-50 nanometers with a ferment molecule. This capsule acts as a reusable trap that not only absorbs but also neutralizes free radicals.