• Number 345  |
• September 5, 2011

Team explores new technologies for improving prosthetic limbs

A team of scientists from DOE’s National Energy Technology Laboratory (NETL) and the University of Pittsburgh’s Bioengineering Department are using new forms of nanotechnology to improve neural-controlled prosthetic implants. These technologies are of particular interest to the U.S. military for treating soldiers and veterans who have suffered loss of limb during service. Neural-controlled prosthetics allow recipients to manipulate their artificial limbs by means of microelectrode implants placed in the brain or in other neural tissue. One major barrier limiting the development of these prosthetics is decreased performance over time (due to rejection of the microelectrode implant, the formation of scar tissue at the neural implant, or the loss of neurons in areas surrounding the implant). Microelectrode implants that can deliver anti-inflammatory drugs and other anti-rejection medicines in the vicinity of the electrode are being explored to improve these prosthetic devices.

The NETL and PITT-Bioengineering team have addressed the controlled release of anti-inflammatory drugs for implant applications by using drug delivery devices based on carbon nanotubes. The carbon nanotubes have diameters of about 10 nanometers and lengths of about 50 micrometers, making them attractive for storing and delivering small quantities of drugs directly to the implantation site. Furthermore, these carbon nanotubes are electrically conductive and can be chemically functionalized to facilitate the interaction of the drug with the carbon nanotube. The collaborative research team investigated a series of carbon nanotubes and was able to demonstrate that carbon nanotube-based drug delivery systems outperformed standard delivery systems by improving the amount of drug released during electrical stimulation and increasing the lifetime of the drug delivery device. The released drug was then tested for bioactivity in cultures of microglia, the key player of the implant-induced immune reaction. The anti-inflammatory drug delivered from the carbon nanotube devices effectively deactivated these cells. These results were recently published in the journal, Biomaterials (Vol. 32, pp 6316-6323).

[Linda Morton, 304.285.4543,
Linda.morton@netl.doe.gov]