BYU engineers have developed an instrument that measures the electronic properties of material and could be used to differentiate cancer from healthy tissue.
"It's basically measuring the resistance to an applied voltage. Cancerous tissue has a different resistance when it's measured," said Aaron Hawkins, associate professor of electrical and computer engineering at Brigham Young University, who has been working on the project.
The goal is to hone the instrument, as yet unnamed, to the point where it could examine living cells to learn many things, including how the cells respond to particular medical treatments.
The project started because another assistant professor of electrical engineering, Travis Oliphant, wanted to look at cells "all the way down to the cellular level, to detect things you couldn't normally see with an optical microscope," Hawkins said. "He wanted to measure, for instance, what water flow looks like within a cell. We think water would have different electrical properties at different parts of the cell. To see that, you have to see very, very small features."
When the project started, they could get high-resolution images of material as small as 200 microns in size. They've refined it to the point they can get images at 30 microns and hope eventually to be able to see clearly below 1 micron.
Pathologists use stains to differentiate cancerous and healthy tissue. And the cells are all dead at the time. The prototype instrument they've created uses a completely different marker system based on the variations in resistance to the electrical voltage. Because of that, it can be applied to live cells, not just dead ones.
Because cancer resists voltage differently than healthy tissues, their technology, which creates black and white images, shows previously unseen aspects of the tissue or anything else being examined, Hawkins said.
"The real goal is to get down to looking at individual cells. If we can make that work, we can unlock a lot of things in biology that are a mystery in how cells function and communicate, inside the cell itself."
He said there's so much to learn about how cells work that "we don't even know what questions to ask yet."
At its current capability, he said, "I could see it being used for biopsies, looking at tissue slices and trying to determine whether something is healthy or not. But we're not really pursuing that that heavily. We are more interested in going to a smaller and smaller scale."
Oliphant told the BYU news service it might help overcome a barrier in diagnosing illness.
"One of the real difficulties in diagnosing illness is looking at an image and having it tell you something meaningful about what's going on with injured or sick cells," he said. "But if you could see that a cell was producing the wrong kind of protein based on the change in electrical resistance, you could more easily determine what was going wrong in a patient's body. Once you understand how things work, it's much easier to combat or fix things that are wrong."
Hawkins, Oliphant and Stephen Schultz, also on the engineering faculty, developed the prototype, which is described in "Applied Physics Letters." They wrote the paper, along with Hongze Liu, a graduate student. The project involved a team of undergraduate engineering students, as well.
Because they're seeing things that can't otherwise be observed, they don't know what it will ultimately mean. They expect that it could open many doors in biology and medicine for research and discovery.
A professor of biophysics at the Mayo Clinic College of Medicine, James P. Greenleaf, called it a "very important and novel method of imaging" and said it provides information that usually can't be imaged.
To create an image with the prototype, engineers put a sample on a flat aluminum-coated silicone wafer that sits in a container filled with water. A tiny probe goes in right above the sample and moves across it like a scanner attached to a computer, but this probe takes voltage measurements. Since electrical current is resisted differently by different things, it creates an image of light and dark hues. Cancer shows up much darker than healthy tissue.A new generation of both the instrument and the probe are being created even as this one is being introduced.
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