Spinal cord injuries, serious stroke and severe traumatic brain injuries affect more than 5 million Americans at a total cost of $65 billion a year in treatment. Is there any hope?Researchers from MIT and Hong Kong University come to give us hope. The group actually managed to partially restore vision to rodents blinded by damage caused to their brains’ visual system. The secret of success is a tiny biodegradable scaffold invented by MIT bioengineers and neuroscientists. This scaffold is formed by a self assembling peptide peptides being fragments of proteins composed by amino acids and water. In particular Shuguang Zhang, associate director of the MIT Center for Biomedical Engineering (CBE) discovered self-assembling peptides in 1991 by accident and has been working with them ever since. Zhang discovered that placing certain peptides in a salt solution causes them to assemble into thin sheets of 99 percent water and 1% percent peptides. These sheets form a mesh or scaffold of tiny interwoven fibers. Zhang and his team realised that neurons can actually grow through the nanofiber mesh, which is similar to that which normally exists in the extracellular space that holds tissue together.The researchers injected a solution containing 99% water and 1% of this self assembling ionic peptide to the damaged rodent brains. Within six weeks the wounds had completely healed and the rodents had regained the ability to turn their eyes and heads towards a sunflower seed in their peripheral vision, though their turning response was slower than normal. The process does not involve growing new neurons. All it does is creating an environment for existing neural cells to regrow their long spiderly projections called axons through which neurons form synaptic connections to communicate with other neurons.That axon regeneration was responsible for the partial restoration of the rodents’ vision. Rutledge G. Ellis-Behnke, Research scientist in the MIT Department of Brain and Cognitive Sciences and co-author of this study states “If we can reconnect parts of the brain that were disconnected by a stroke, then we may be able to restore speech to an individual who is able to understand what is said but has lost the ability to speak. This is not about restoring 100 percent of the damaged brain cells, but 20 percent or even less might be enough to restore function and this is our goal.” The group’s biological mesh seems to be better than currently available biomaterials since it forms a network of nanofibers similar to the brain’s own matrix of cell growth; it can be broken down into natural amino acids which might be beneficial to surrounding tissue and it appears to be immunologically inert, avoiding the problem of rejection by surrounding tissue.Tissue engineer Kevin Shakesheff at the University of Nottingham, UK, sates that although the work is very exiting, it urges for great caution. The injury caused to the rodents’ brain is not representative of more complicated injury or disease in humans. He also notes that the way the scaffold regenerates tissue is currently a mystery and that delivering stem cells to further boost the regenerative process might be an option. The researchers are now testing the self-assembling peptides on spinal cord injuries and hope to launch trials in primates and eventually humans. This study appears in the Proceedings of the National Academy of Sciences (PNAS).
Votes: 0
E-mail me when people leave their comments –

Dr Vishnu Kiran Manam

You need to be a member of The International NanoScience Community - Nanopaprika.eu to add comments!

Join The International NanoScience Community - Nanopaprika.eu