Nanofibers prevent neurons from dying
Traumatic brain injury (TBI) usually leads to disruption of normal brain function. In 2014, 2.5 million people were admitted to emergency departments in the United States with this diagnosis.
In a report to be presented at the annual conference of the American Chemical Society in San Diego this week, researchers report on the development of a self-organizing peptide hydrogel that, when injected into the brain of rats with TBI, increases the growth of blood vessels and promotes the survival of damaged neurons.
With TBI , two processes are noted: primary damage that directly results from mechanical damage to neurons and other brain cells, as well as blood vessels, and secondary damage that occurs a few seconds after injury and can last for many years. It is associated with oxidative stress, inflammation and violation of the blood-brain barrier. Secondary trauma creates a neurotoxic environment that can lead to long-term cognitive impairment. For example, patients who survived TBI may develop motor disorders, depression, etc. Currently, there is no effective restorative treatment for the consequences of TBI.
The researchers suggested that for the treatment of secondary injuries, it is necessary to restore adequate blood supply in the area of damage in order to restore impaired gas exchange and create a favorable environment for the restoration of neuronal function.
Researchers from the New Jersey Institute of Technology have developed peptides that can independently assemble into hydrogels when injected into the body. By including fragments of certain amino acid sequences into peptides, various functions can be given to them. For example, earlier the same group developed angiogenic peptide hydrogels that caused the growth of new blood vessels when injected under the skin of mice.
To adapt their technology for use in the brain, Biplap Sarkar and Vivek Kumar modified peptide sequences to give the hydrogel properties closer to brain tissue, which is softer than most other body tissues. They also included a sequence from the neuroprotective protein ependymine.
Self-assembling peptide nanofibers. Source: Biplab Sarkar and Vivek Kumar.
The researchers tested a new peptide hydrogel on a rat model of TBI. When injected into the site of injury, peptides self-organize into a hydrogel, which acts as a neuroprotective base to which neurons can attach. A week after administration, they tested the brains of rats and found that in the presence of hydrogel, the survival of brain cells significantly improves, this leads to a doubling of the number of neurons at the site of injury compared to animals of the control group. In addition, the researchers noticed signs of the formation of new blood vessels.
According to the authors, one of the next steps will be to study the behavior of experimental animals to assess their functional recovery after treatment with TBI hydrogel. They are also studying a method of treating rats with a combination of a previously developed angiogenic peptide and their new neurohydrogel to see if this will help speed up recovery after TBI. In addition, it is planned to find out whether peptide hydrogels work in the case of diffuse injuries, such as concussion.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru according to EurekAlert: Peptide hydrogels could help heal traumatic brain injuries.