The field of materials science witnessed the accomplishment worth several milestones with the advent of CNT or Carbon Nano Tubes in the year 1991, and ever since then they have found several applications across the different fields of engineering and biomedical sciences. These structures have an impressive portfolio of properties including incredible thermal and electrical conductivity, and mechanical strength.  They have been used to synthesize the toughest fiber ever made, computer chips that run at twice the speed of silicon chips and what’s more: they have also been used to create the world’s blackest material – Vantablack. CNTs are several folds stronger than steel, but only one-sixth as heavy, so nano tube fibers can virtually strengthen almost any material – both biotic and abiotic.

Scientists have now demonstrated that these CNTs may have monumental applications in the field of biological sciences as well, more specifically for reconnecting damaged neurons and treating spinal injuries by using CNT as supporting scaffold of sorts.

CNT isn’t the perfect material to build neural interfaces; no such material exists yet, but it is the most suitable option currently and shows great potential.

Until now, for those suffering from spinal injuries there was little to no chance of ever regaining their motor functions again, as after the injury there is a scar that physically blocks any kind of reconnection of the [original] fibers. But now, the idea is to induce the neurons next to the scar to make new connections.

CNTs have shown to prove exceptionally good for growing neurons and improving their ability to reconnect as they are both tissue-friendly and conductive. Hence they can stimulate electrical connections and electrical activity in neurons.

This was demonstrated in a study conducted by a group of researchers led by Laura Bannerili from the International School for Advanced Studies in Italy, where they extracted neurons from the hippocampus of laboratory rats and deposited them on a carbon nanotube mat and after an incubation period at room temperature, the cells were tested for conductivity and compatibility with the carbon nano tube surface.

Initially, there were some safety concerns about the application of CNTs as their fibrous nature places them in the same class as asbestos. However, it was soon proved, although still unsatisfactorily, that nano tubes do not interfere with the composition of lipids (cholesterol in particular) present in the cell membranes of neurons, since they shared the constitution with the biomolecules. The most significant discovery, however remains to concern the fact that neurons reached maturity faster on a surface of carbon nano tubes.

Carbon nano tubes facilitate the full growth of neurons and the formation of new synapses. Having established the fact that this interaction is stable and efficient is an aspect of fundamental contextual importance.

But if this technique is so revolutionary, why isn’t it being used for treating people with spinal injuries and neural disorders?

This is mainly because this procedure is still in its experimental stages and quite a few major issues are yet to be addressed, as it is still not completely understood how the integration of carbon nano tubes impacts the creation and structure of neuronal pathways.

One of the prominent concerns shared by many in scientific community is that carbon nano tubes, being fibrous materials, have been likened to asbestos, a mineral fiber with carcinogenic properties. Despite arguments dismissing this inclination, substantial and convincing proof has not yet been established, as discussed earlier in this writing.

So, this technique would only be able to progress fully ahead only when the impact of CNT on physiological and biochemical pathways has been completely understood and safety of the material has been entirely established in-vivo.

The Future

To test whether CNT had some biocompatibility, Bannerili and her colleagues tested it on living rats. They implanted CNT meshes in the cortices of adult rat brains and examined the animals four weeks later. Both neurons and microglia had grown into the mesh and tissue inflammation had been minimal.

A major milestone in the development of this technique will be achieved when CNT is implanted in-vivo in the spinal cord, after having demolished every roadblock that arises in the process. As for now, this technology continues to promise more innovative health care and is a potential potent weapon in combating spinal cord injuries.

Author: Nikhil More 
Editor: Aastha Munjal
Date of Publishing: 11th Jul 2017
Featured Image Source: Shutterstock
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