Nanotube Fibers Could Restore Electrical Health to Hearts

Soft, flexible nanotube fibers could be used to bridge scar tissue and restore electrical conductivity to damaged heart tissue, according to a new study.

Developed by researchers at Rice University (Rice, Houston, TX, USA) and the Texas Heart Institute (Houston, TX, USA), the fibers are miniscule, about a quarter of the thickness of a human hair, but still contain millions of microscopic nanotubes made of pure carbon. Since the fibers are soft, flexible, and extremely tough, the researchers claim they should be far more suitable to fulfill the biological requisites needed to deliver electrical power to devices such as pacemakers.

The nanotube fibers exhibit low impedance, which allows electricity to move from tissue across the scar-tissue bridge and back with ease, far better than with the metal leads currently used. According to the researchers, the fibers have potential for many other applications, including helping patients with Parkinson's disease (PD) who require brain implants to treat their neurological conditions. The researchers are continuing to test the fiber's biocompatibility, and expect that human trials are just a few years away.

“Though the fibers were developed to replace the miles of cables in commercial airplanes to save weight, their potential for medical applications became quickly apparent,” said chemist and chemical engineer Matteo Pasquali, PhD, of Rice University. “We didn’t design the fiber to be soft, but it turns out to be mechanically very similar to a suture, and it has all the electrical function necessary for an application like this.”

“They’re like extension cords; they allow us to pick up charge from one side of the scar and deliver it to the other side. Essentially, we’re short-circuiting the short circuit,” said Mehdi Razavi, PhD, director of electrophysiology clinical research at the Texas Heart Institute. “Should these more extensive studies confirm our initial findings, a paradigm shift in treatment of sudden cardiac death will be within reach, as for the first time the underlying cause for these events may be corrected on a permanent basis.”

“Metal wires themselves can cause tissue to scar; if you think about inserting a needle into your skin, eventually your skin will react and completely isolate it, because it’s stiff,” added Flavia Vitale, a research scientist in Pasquali’s lab who is developing nanotube fiber applications. “Scar will form around the needle. But these fibers are unique; They’re smaller and more flexible than a human hair and so strong that they can resist flexural fatigue due to the constant beating of the heart.”

Related Links:
Rice University
Texas Heart Institute