A new technology may help doctors bring beneficial drugs to injured areas of the brain without invasive means, helping address traumatic brain injuries that span from mild concussions to violent accidents leading up to memory loss.
Researchers from the Sanford Burnham Prebys Medical Discovery Institute (SBP) led the study. They said the technology was based on a peptide sequence of four amino acids — cysteine, alanine, glutamine and lysine (CAQK) — that can recognize brain tissue injury.
Traumatic brain injuries affect around 2.5 million Americans every year, usually from car crashes, falls, and violent events. The initial injury can hardly be repaired, but the lasting damage of breaking open brain cells as well as blood vessels in the following hours and days can be managed.
"This peptide could be used to deliver treatments that limit the extent of damage," reported senior study author and professor Dr. Erkki Ruoslahti.
According to first author and postdoc researcher Aman Mann, current therapies for acute brain injuries seek to stabilize the victim through reducing intracranial pressure and keeping blood flow. However, there is yet to be any approved drug to halt the events leading up to a secondary injury.
In preclinical trials, more than 100 compounds are being tested to decrease brain damage after injury — they aim to block secondary damage such as high free radical levels, inflammation, over-excitation of brains and signaling that results in cell death.
The team had the goal of finding an alternative to inject therapeutics into the brain directly — an invasive move that can lead to complications. They studied the peptide to deliver drugs and nanoparticles in a way it can be given intravenously, but still able to get to the injury site in helpful quantities.
The CAQK peptide binds to parts of the chondroitin sulfate proteoglycans, which are large and sugar coated proteins that increase around the injury site. After binding to them, the peptide carries drug-filled packages to the areas of damage — an effect seen in both mouse and human subjects.
The peptide could also help devise ways to identify a mild brain injury when it attaches to materials detectable by medical imaging devices, Ruoslahti added. Since it can provide nanoparticles that are loadable with large molecules, the peptide could prompt new enzyme or gene-silencing treatments.
The researchers are currently testing their technology in central nervous system injuries, such as multiple sclerosis, in animal models.
The findings were detailed in the journal Nature Communications.