The study, which was coordinated by the International School for Advanced Studies (SISSA) in Trieste, in collaboration with the University of Rome Tor Vergata and the University of Trieste, also observed biocompatibility in vivo of the material, demonstrating that implanting it into the brain of small rodents does not cause large scars or a marked immune response. The study, published in Science Advances (an important relative of the prestigious journal, Science) demonstrate that the material shows promise for biomedical implementation and could be evaluated for prosthetic nervous system applications.
«Under the microscope, it looks like a knotted tangle of tubes. It was initially studied by Maurizio De Crescenzi’s team at the University of Rome Tor Vergata for cleaning up spilled hydrocarbons in the sea," explains Laura Ballerini, SISSA Professor and coordinator of the
In the present study, Ballerini and her team first investigated the material’s reaction to nerve tissue in vitro. «We explanted two spinal cord segments and cultured them together but separated by 300 microns," says Sadaf Usmani, a PhD student at the School and first author of the study. «In those conditions, without any scaffolds reconstructing the space between the two explants, we observed growth of nerve fibers which extended in a straight bundles in any direction, but not necessarily towards the other tissue. If we insert a small piece of the carbon sponge into the space between the two, however, we see dense growth of nerve fibers that fill the structure and intertwine with the other sample.»
«Observing fiber reaching the contralateral explant is not enough, however," points out University of Trieste researcher and one of the authors of the study, Denis Scaini. «You have to show that there is a functional connection between the two populations of neurons." For this, SISSA Professor, David Zoccolan and his team’s contribution was crucial. «With signal analysis techniques they had already developed, we were able to demonstrate two things: first, that spontaneous nervous activity in the two samples was actually correlated, indicating a connection, that was not there when the sponge was absent, and second, that by applying an electrical signal to one of the samples, the activity of the second sample could be triggered, but only when the nanotubes were present.»
Tests for Biocompatibility
The results in the lab were extremely positive. But this was not sufficient for Ballerini and her colleagues. «In order to continue to invest additional energy and resources to the study for potential applications, is crucial to test if the material is accepted by living organisms without negative consequences," says Ballerini.
To perform these tests, Ballerini’s team worked closely with SISSA
«In conclusion," says Ballerini, «the excellent results at the structural and functional level in vitro and in vivo showed biocompatibility are encouraging us to continue this line of research. Thesematerials could be useful for covering electrodes used for treating movement disorders likeParkinson’s because they are well accepted by tissue, while the implants being used today become less effective over time because of scar tissue. We hope this encourages other research teams with multidisciplinary expertise to expand this type of study even further.»
Source: http://www.sissa.it/sites/default/files/images/A%20bridge%20of%20carbon.pdf
