Scientists from the New York University School of Medicine, the University of Tokyo, and the MIT are developing platinum nanowires, that one day might allow clinicians to monitor individual brain cells. These nanowires, designed to be delivered retrogradely via the arterial tree, might offer in the future new treatment opportunities for chronic neurological disorders:
Writing in the July 5, 2005, online issue of The Journal of Nanoparticle Research, the researchers explain it is becoming feasible to create nanowires far thinner than even the tiniest capillary vessels. That means nanowires could, in principle, be threaded through the circulatory system to any point in the body without blocking the normal flow of blood or interfering with the exchange of gasses and nutrients through the blood-vessel walls.
The team describes a proof-of-principle experiment in which they first guided platinum nanowires into the vascular system of tissue samples, and then successfully used the wires to detect the activity of individual neurons lying adjacent to the blood vessels…
“Nanotechnology is becoming one of the brightest stars in the medical and cognitive sciences,” said Mike Roco, Senior Advisor for Nanotechnology at the National Science Foundation (NSF), which funded the research.
Already, the researchers note, physicians routinely use arterial pathways to guide much larger catheter tubes to specific points in the body. This technique is frequently used to study blood flow around the heart, for example.
Following the same logic, the researchers envision connecting an entire array of nanowires to a catheter tube that could then be guided through the circulatory system to the brain. Once there, the wires would spread into a “bouquet,” branching out into tinier and tinier blood vessels until they reached specific locations. Each nanowire would then be used to record the electrical activity of a single nerve cell or small groups of them.
If the technique works, the researchers say, it would be a boon to scientists who study brain function. Current technologies, such as positron emission tomography (PET) scans and functional magnetic resonance imaging (fMRI), have revealed a great deal about how neural circuits process, say, visual information or language. But the view is still comparatively fuzzy and crude. By providing information on the scale of individual nerve cells, or “neurons,” the nanowire technique could bring the picture into much sharper focus.
“In this case, we see the first-ever application of nanotechnology to understanding the brain at the neuron-to-neuron interaction level with a non-intrusive, biocompatible and biodegradable nano-probe,” said Roco. “With careful attention to ethical issues, it promises entirely new areas of study, and ultimately could lead to new therapies and new ways of treating diseases. This illustrates the new generations of nanoscale active devices and complex nanosystems.”