"Carbon nanotubes might have a role in targeting drugs to tumour cells or delivery of drugs to the nervous system"
Todd Pappas is co-author of a study published in the May issue of the Journal of Nanoscience and Nanotechnology on the ability of carbon nanotubes to carry electrical signals to nerve cells. He answers Scitizen?s questions.
What is the context of your research?
We were very interested in seeing how nanomaterials, in this case carbon nanotubes, interface with electrically excitable cells. We know that nanomaterials, and especially carbon nanotubes, have very interesting electrical proprieties, including high conductivity or semi-conductivity. They are small and we believe that they are optimal for interfacing with neurons or cardiac cells and passing their electrical proprieties on to neurons and cardiac cells.
What are carbon nanotubes and for what purposes are they used?
Carbon nanotubes are basically extremely small carbon molecules in an interesting configuration, they are like a rolled sheet of graphite. They are small as less than one nanometre in diameter and their length ranges anywhere from twenty nanometres up to two or three hundred nanometres or maybe even more. They are made only of carbon and because of the way they are structured they have different types of conductivity, different types of optical properties. At this point they have mostly been researched for the promise of what they can do. However several applications are now coming out, applications in electronics or applications in strong materials, so a lot is being done and a lot more can be done in nanobiotechnology.
In your report you talk about neuroblastoma cells. What are they?
A neuroblastoma cell is something we use as our model neuron. Usually when we do in vitro studies we start with simple systems that we can control, and neuroblastoma cells are cells that we can grow in culture in an incubator, alone in a dish, and have electrical properties similar to that of real neurons, so that we can pass the proprieties of the carbon nanotubes on the neuroblastoma cell before we commit to the resources on doing work on real neurons.
We imagine that most neurons will work the same. Given an extrinsic electrical stimulus trough the carbon nanotube sheet that we made, we will be able to activate neurons.
What are the results of your research?
The research was kind of broken up into two basic parts. The first was a biocompatibility study. Could we show that neurons will grow and be “happy” growing on nanotubes and, could we control growth by putting functional groups on those nanotubes? Our collaborators at Rice University did the functionalization of those nanotubes.
Part two was actually looking to see if we could pass an electrical signal from the nanotubes to the neurons or to the neuroblastoma cells.
What are the implications of your discovery?
We hope there are implications in biomedicine and that’s where our target is. We hope that carbon nanotubes will used in electrically-active, biocompatible substances or surfaces that interface with neurons in the design of prosthesis or movements or for balance. Also we believe that carbon nanotubes might have a role in targeting drugs to tumour cells, delivery of drugs to the nervous system, or delivery of chemicals for growth of developing neurons. I think the possibilities are endless. Right now we are trying to look at interfacing with neurons and the electrical proprieties.
Can you develop?
We are going several ways actually. There is some work that is being done on the first approximations of developing prosthetic devices by taking the nanotubes and making patterned electrodes with them. Also, we are looking more into using functionalized nanotubes in surfaces and to target single nanotubes for drug delivery, we think that they have the properties that might facilitate this.
Dr. Todd Pappas thank you.
Todd Pappas works at UTMB's Center for Biomedical Engineering.
Interview by Francesca Gilibert