Recently, bioengineers at the University of Michigan used a nanoparticle to help avoid paralysis caused by spinal cord injuryAnimal experiments have shown that injecting the nanoparticles after injury in mice can effectively promote nerve regeneration in the spinal cord and help restore motor abilityThe study was published in the Proceedings of the National Academy of Sciences (PNAS)the nanoparticles work because they can effectively "intercept" immune cellsImmune cells don't help repair wounds? Usually this is the caseActivated immune cells gather around the wound and actively remove dead cell fragments, a process that promotes tissue healing and initiates regeneration and repairhowever, things are different in the central nervous system, which is made up of the brain and spinal cordNormally, the blood-brain barrier isolates disturbed immune activity from nerve cellsWhen the spinal cord is injured, the barrier is broken, and immune cells are able to enter the injured area and release inflammatory cytokinesThe active immune response not only does not help, but also causes greater damage to the nerve tissue of the spinal cord, which is not accustomed to this "treatment", leading to the rapid death of neuronsis the nerve's myelinMyelin is wrapped outside the nerve fibers and helps the nerves transmit signals, but the inflammatory response creates scars in the myelin and becomes a major impediment to nerve regeneration in the spinal cordHowhow to prevent the immune system from overreacting to nerve damage? Professor Lonnie Shea came up with an idea: "Instead of overcoming the immune response, we can also use the immune response to help us promote the therapeutic response."with this purpose, the researchers devised a novel nanoparticle therapyThey let nanoparticles act as fragments of injured cells, combine them with the immune cells in the circulatory system that cause inflammation, and transfer them to the spleen, indirectly reducing the burden on the spinal cord-injured areathese nanoparticles are made from polylactic acid-hydroxyacetic copolymers, a biodegradable polymer organic compound that has been approved by the FDA as reabsorbable sutures Because nanoparticles work through physical properties such as size and charge, they do not attach to the drug themselves, thus avoiding the adverse reactions that the drug may have researchers tested the effects of nanoparticles in mice with spinal cord injuries Nanoparticles are injected into the mice through intravenous injections as soon as the mice are injured For one week of continuous injections, the researchers observed a significant reduction in congenital immune cells that accumulate at the trauma site, compared with only a quarter of the control group! Accordingly, after 4 weeks of injury, the scars of nerve fibers were also reduced by half compared to the control group mice immediately after spinal cord injury injection nanoparticles, reducing the concentration of inflammatory immune cells at the injured site (Picture source: References) on the other hand, due to improved microenvironment, some cells in the immune system with lower degrees of inflammation, such as some macrophages, successfully reached the site of the injury after injection of nanoparticles, to help with healing and nerve regeneration about three months after the spinal cord injury in mice, the researchers observed a marked improvement in nerve regeneration in mice that injected nanoparticles immediately after injury About 40% of the neuromyeloids recovered from myelin, almost the same as the uninjured side At the same time, the movement of the hind limbs of the mice showed a significant improvement post-limb motor function score showed that mice injected with nanoparticles after injury achieved significant improvement compared to the control group (Image source: References) researchers compared the injectable nanoparticles to emergency drugs for the central nervous system, hoping to help prevent more severe damage in the first time after a patient's brain or spinal cord injury this treatment strategy is even more promising, it may have a wider range of applications Because it effectively targets immune cells, it may benefit more patients with inflammatory diseases, in addition to introducing new therapies for patients with spinal cord injuries "Almost all major diseases, such as autoimmune diseases, cancer, regeneration, are based on the immune system, " says Professor Shea If there are tools that can target immune cells and redirect them to achieve the desired response, there is much to be done to treat or manage disease "
References: ' Jonghyuck Park et al., (2019) Intravascular innate immune cells reprogrammed via intravenous nanoparticles to promote yn rhoi fod yn cyhoeddus Proceedings of the National Academy of Sciences 10.1073/pnas.1820276116 'EpiPen' for spinal cord s Retrieved Jul 18, from the original title: Repairing spinal cord injuries, these nanoparticles may be the first to help