COLUMBUS, Ohio -- A newly patented device co-developed by engineers at Ohio State University is helping scientists separate cells in the laboratory for transplant and cancer research.
The device may one day help the military as well, by detecting biological warfare agents, said Jeffrey Chalmers, professor of chemical engineering at Ohio State and co-investigator on this joint project with the Cleveland Clinic Foundation.
The patent represents an improvement on devices already on the market that tag cells with magnetic markers and sort them using magnetic fields. Researchers often use the technique to sort bone marrow cells for transplant, or to find cancer cells in blood samples.
"We didn't invent magnetic cell separation -- we're refining it," explained Chalmers. "This patent covers a method and device for better measuring how well we magnetically label cells and how magnetic they are."
This latest patent is the third Chalmers and his colleagues have received during the last year for related technologies. He conducts this work with Maciej Zborowski and Lee Robert Moore, both of the Cleveland Clinic Foundation.
The device will better enable scientists to evaluate the quality of the magnetic particles, called reagents, that they use to tag cells for separation, Chalmers said.
"No one else can evaluate magnetic reagents like we can," he said.
The researchers use a prototype of the device to look for human stem cells in umbilical cord blood, as well as for transplant and cancer research.
Cancer researchers are currently trying to find out whether cancer cells in the blood can be used as a reliable indicator of whether a patient's cancer has metastasized, Chalmers explained. Some researchers suspect that both metastatic and non-metastatic breast cancer may shed cells in the blood.
This device may aid researchers' efforts by making cancer cells easier to tag and find, Chalmers said. He added that the device may one day be able to separate a large quantity of cells very quickly -- testing the blood of many different patients one after the other, for instance.
The device works by measuring how cells move when suspended in a magnetic field. The researchers target specific cells by attaching magnetic particles to antibodies that will seek out those cells and bind with them. Those cells are then delivered to a region of very high magnetic field. Researchers can identify the type of cell by measuring how fast the cell moves in this high magnetic energy zone.
When they needed to know how different cells flowed in magnetic fields, the researchers were able to take advantage of software already under development at Ohio State for fluid mechanics research.
The greatest challenge came from designing the magnetic fields, Chalmers said, and building upon fundamental mathematical concepts to gauge the interaction between the magnetic fields and individual cells.
Chalmers said the new device represents an improvement because it allows researchers to more carefully measure that interaction.
While more primitive magnetic flow separators are commercially available, laboratories most often separate cells with a flow cytometer, a device that employs a laser beam to examine cells flowing in a stream of water.
Chalmers said the new magnetic cell separator could potentially cost less to manufacture than a flow cytometer, and wouldn't require frequent laser tuning as flow cytometers do.
He sees the new device as a necessary extension of molecular cancer research. "Over the years, we've learned a great deal about cancer on the molecular level, but we're still lacking analytical tools to diagnose and treat cancer," Chalmers said. "We want to take that molecular understanding we've gained and apply it in a practical sense with instrumentation."
He added that many other applications for magnetic cell separation wait to be explored.
For instance, researchers have used magnetic separation techniques to find contaminants in food and water. Chalmers has talked to the U.S. military about turning the new magnetic cell separator into a portable device to test food, water, and air for biological warfare agents.
This work was supported by grants from the National Cancer Institute, National Science Foundation, and the Whitaker Foundation. Some funding was provided by NovaMedics, a for-profit subsidiary founded by the Cleveland Clinic to commercialize technology developed there.
Contact: Jeffery Chalmers, (614) 292-2727;
Chalmers.1@osu.edu
Written by Pam Frost, (614) 292-9475;
Frost.18@osu.edu