Chitosan against spinal cord injuries
Spinal cord injuries are among the most severe and poorly treatable conditions, usually leading to irreversible disability, including loss of muscle function, as well as sensitivity and disorders in the autonomic nervous system.
Currently, researchers working on mouse models and primates have already come quite close to successfully treating severe spinal cord injuries by stimulating the restoration of vertebral nerves.
The result of the joint work of researchers from different research institutions in China was the method of treatment and subsequent functional recovery of rhesus monkeys with induced spinal cord injuries using chitosan particles loaded with neurotrophin-3 (chitosan-HT3).
Chitosan is a biodegradable polymer extracted from the shells of shrimps and other crustaceans. It already has a number of applications in medical practice, including as a hemostatic and antibacterial agent. In addition, chitosan is used as a carrier for targeted drug delivery. Neurotrophin-3 is a protein factor that promotes the growth and differentiation of new neurons and interneuronal synapses.
Neurons of the central nervous system regenerate very poorly even in the most favorable conditions, and the process of restoring spinal cord injuries is suppressed by a number of mechanisms. Moreover, after damage, their recovery is suppressed even more due to the effects of inflammatory cytokines and other factors.
Earlier attempts to solve this problem were aimed at making the microenvironment in the area of acute injury more favorable for nerve regeneration. Despite certain positive results of experiments on rodents, they did not justify themselves during clinical trials. Therefore, the authors decided to first reproduce the results of experimental therapy with the chitosan-HT3 complex on primates obtained on rodents.
As part of their study, they injected a complex into 1-centimeter defects of partially dissected in the thoracic spinal cord of adult rhesus macaques. Chitosan acted as a matrix framework containing and gradually releasing neutrophin-3 into the damage zone for a fairly long time. In rodent experiments, this method suppressed the activity of inflammatory cells and stimulated endogenous nerve stem cells to proliferate, differentiate and form neural networks that transmit nerve signals to and from the brain.
Using a combination of non-invasive methods for evaluating the results, including functional magnetic resonance imaging (MRI), diffuse tensor MRI and kinematic walking analysis, the researchers confirmed that the approach provides comparable results on the Rhesus macaque model. They also demonstrated that monkeys with smaller lesions remaining after treatment were characterized by higher mobility. This is most likely due to the anti-inflammatory effect of the chitosan-neurotrophin-3 complex.
The article by Jia-Sheng Rao et al. NT3-chitosan enables de novo regeneration and functional recovery in monkeys after spinal cord injury is published in the journal Proceedings of the National Academy of Science.
Evgenia Ryabtseva, portal "Eternal Youth" http://vechnayamolodost.ru