With each issue, Trib+Health brings you an interview with experts on issues related to health care. Here is this week's subject:
Matteo Pasquali is the A. J. Hartsook Professor and chairman of the Department of Chemistry at Rice University, and a professor in chemical and biomolecular engineering, chemistry, and materials science and nano-engineering. Pasquali directs the laboratory of complex flows of complex fluids, which studies the interaction of flow and liquid micro- and nano-structure in complex fluids, with a focus on the processing of multifunctional materials and the manufacturing of soft conductors, particularly based on carbon nanotubes and graphene. The lab created carbon nanotube fibers, with potential for application in brain surgeries.
Editor's note: This interview has been edited for length and clarity.
Trib+Health: How did these carbon nanotubes come about?
Matteo Pasquali: We’ve been making materials that have a unique combination of properties. When you think about all the textile materials that we know — cotton, silk, polyester — none of them conduct electricity. When you think about materials that conduct electricity — copper, aluminum, steel — they are all stiff and pretty fragile when you make them really thin. Then they break easily.
What that means is that we don’t really have materials that are very well suited to make electrical contact with the body. We can’t use the soft materials because they don’t conduct electricity. But the hard materials have a lot of issues. They scar, they can break.
What we created are carbonite fibers. If you look at them, if you have them in your hand, you would think you have silk strands, but they are highly conductive, about as conductive as metal. These materials are great to provide an interface for the electrical functions of the body.
The way our brain communicates with the rest of our nervous system is all through electrical signals. These fibers that we’ve made are great as an interface material for the brain. And specifically, one of the things that has been really difficult to do with metal was using both to deliver stimulation to the brain and send signals. We are able to do that with these fibers. They work really well from the electrical point of view. They don’t scar the tissues. They are very stable. They can be implanted over weeks and they deliver steady signal.
It is exciting. The material was actually developed for aerospace and military purposes, and can be used for medical purposes.
Trib+Health: What type of procedure would warrant using these fibers?
Pasquali: There is a sector of procedures that right now are done on animals to study cognition. These are interesting from the mental point of view. There is already protocol for stimulating the brain of patients who have Parkinson’s. Right now, this is done with very invasive, large metal electrodes. What we hope is that the kind of materials that we are making allow us to make much smaller electrodes that are much less invasive. They can be much more precise in sensing the signal that comes from the brain and arrive as Parkinson’s tremors, and then deliver a signal in the right location of the brain, a counteracting stimulus that could then stabilize symptoms.
Trib+Health: If this was created for an aerospace application, what led to finding this material for medical uses?
Pasquali: It was speculated pretty widely for a long time that carbon nanotubes should be strong, electrically conductive and lightweight. That is based on measurements and theoretical concentrations that were made on carbon nanotube, about 20 years ago. That is why the Air Force was interested, because the idea of having a material that can be both electrically conductive as well as strong and lightweight is important for aerospace applications because it can create weight savings and performance improvement and aircraft systems.
What was not expected at all was that the material was so flexible. Pretty much all of us thought it would behave like a carbon fiber, quite stiff and brittle. Instead, it behaves just like silk or cotton. It is very flexible, very pliable and it was just unexpected.
Trib+Health: What is the timeline to see these fibers used in procedures?
Pasquali: It is going to take several years. It is still pretty early research. If we don’t try these out, nothing will ever happen. It will take not only time but considerable funding and multiple researchers to really get this done.
The brain is very important and it is the first thing we went after, but this is really something that is much broader and could be used in the whole central nervous system as well as the heart. We are really looking at these as a very general interface material to work with any of the electrical systems of the body.