Sensors to Detect Illness From Within
Building Built-In Bio-Sensors
Tiny Device in Blood Could Warn of Radiation or Illness
By Paul Eng
July 12 — One day, the eyes will be more than just windows to someone's soul. They'll also be the portal to a person's health.
Nanotechnology could one day lead to tiny sensors that can be embedded within an astronaut's blood cells to help monitor for signs of hidden radiation damage that can occur during extended stays in outer space. (NASA TV/AP Photo)
At least, that's what Dr. James R. Baker, Jr. and a team of scientists at the University of Michigan hopes will happen with the help of nanotechnology — microscopic devices that are thousands of times thinner than a human hair.
And the concept, an extension of years of research conducted by Baker and others at the university's Center of Biological Nanotechhnology to find new ways to detect and fight cancer, sounds fairly simple.
At the heart of the new detection method would be tiny spheres of synthetic polymers called dendrimers.
Each sphere, or nanosensor, measures a mere five nanometers — or five billionths of a meter — in diameter. (By comparison, the diameter of a typical pinhead is a million nanometers wide.) That means billions of nanosensors can be packed within a small amount of space.
The nanosensors would then be delivered into a human through a skin patch or even digested with food. Once in the body, the tiny nanosensors embed themselves within lymphocytes — the white blood cells that provide the body's defenses against infection and disease.
As lymphocytes fight certain disease and conditions — say a common cold or the body's exposure to radiation — the protein composition within the cells change. Each nanosensor, coated with special chemical agents, would fluoresce or glow in the presence of those protein changes.
And to see the glowing signs of the nanosensors, Baker has an ingenious solution.
"Our plan is to develop a retinal-scanning device with a laser capable of detecting fluorescence from lymphocytes as they pass one-by-one through narrow capillaries in the back of the eye," says Baker. "If we can incorporate the tagged sensors into enough lymphocytes, a 15-second scan should be sufficient to detect cell damage."
Backed by NASA for Further Study
The concept hasn't gone far beyond the research stage. But it has warranted the attention — and funding — of NASA.
The government space agency recently bestowed a three-year, $2 million grant to Baker and the Center for Biological Nanotechnology to research the concept further.
"Radiation-induced illness is a serious concern in space travel," says Baker. "Our goal is to develop a non-invasive system that, when placed inside the blood cells of astronauts, will monitor continuously for radiation exposure or infectious agents." Baker believes that the concept could work, given that it's based on similar nanotechnolgy the team has been working on for cancer detection.
But he admits that a lot of research has to be done.
For example, he says it's still unclear if the fluorescent glow of the nanosensors in the white blood cells could be picked up amid the sea of darker red blood cells. And although he and the research team at the university have had some success in cell cultures in a lab setting, the real test will be if the concept works in virto.
Baker says he hopes to begin testing the process with lab animals, perhaps sometime later this year.