Chemical engineer Christine Duval wins U.S. Dept. of Energy Early Career Research Grant
Case Western Reserve’s Christine Duval selected to accelerate work on purifying radioactive isotopes, used in diagnostic imaging, cancer treatment
A Case Western Reserve University chemical engineer who is pioneering a faster and more sustainable means for increasing the national supply of radiotherapies for cancer treatment has been selected to receive an Early Career Research grant by the U.S. Department of Energy’s (DOE) Office of Science.
Christine Duval, an assistant professor in chemical engineering in the Case School of Engineering, is among 75 scientists nationally to receive funding for research as part of the DOE’s Early Career Research Program. The award is for at least $150,000 per year to cover summer salary and research expenses and is planned for five years—or a total of at least $750,000.
Duval is believed to be among only a few researchers ever from Case Western Reserve to win the award and is the first known winner from the Case School of Engineering.
“Dr. Duval is a creative and energetic scientist, and this award recognizes the originality and anticipated impact of her ideas,” said Dan Lacks, chair of the Department of Chemical and Biomolecular Engineering. “She leverages her expertise in two distinct fields—membrane and nuclear sciences—to propose innovative ways to extract the medically important isotopes from natural systems.”
Duval’s proposal to the DOE said “the overall goal of the proposed research is to increase the availability of medical isotopes for fundamental research and clinical trials, which requires transformative change from current production and purification methods,” and that such a change would increase the U.S. supply of medical isotopes—including those used as radiopharmaceuticals.
Radioactive isotopes, or radioisotopes, is the broad term for any unstable radioactive substances; radiopharmaceuticals are a new class of drugs made from specific radioisotopes that can be used to diagnose and treat disease.
“We’re excited about it because it will allow our lab to continue to do this work and improve on it by bringing on more student researchers. It also builds on our existing collaborations with Argonne National Laboratory,” said Duval, who came to Case Western Reserve in 2017 and established a lab that “develops advanced materials to enable radiochemical separations for nuclear forensics and human health.”
Earlier this year, Duval was also tabbed by the DOE to lead a new program awarding graduate research fellowships through the federal Nuclear Energy University Program to support students pursuing graduate degrees in nuclear engineering, nuclear science and related fields that will advance the field of nuclear energy.
What is isotope purification?
The new DOE grant is specifically awarded to support Duval’s current work to try to perfect a signature process for faster, more sustainable purification of the radioisotopes. They are necessary for diagnostic imaging, but also used more frequently in radiotherapy aimed at destroying targeted cells in the body, such as cancer cells.
Radioactive isotopes are atoms that have a proton-to-neutron ratio that is fundamentally unstable, so they will decay over time in a natural progression toward stability. In radio imaging, physicians use the radioisotope as a tracer to examine blood-flow to specific organs and assess organ function or bone growth as it circulates through the body or is taken up only by certain tissues.
While some commercially available isotopes are produced on-demand in nuclear reactors or accelerators, many emerging isotopes for radiopharmaceuticals are manufactured by drawing them out from dissolved radioactive waste.
Scientists push the dissolved material through a column filled with beads, or resin, which binds to desired product, allowing undesired material to drip from the bottom. After separation, the desired product is washed from the column and collected for use.
That process, the accepted method for more than 50 years, can take up to several hours or even three to four days, depending on the radioisotope, Duval said. Further, because the material is radioactive, it diminishes over time because of its half-life.
“It’s literally being done by PhD scientists by hand and it’s expensive and slow,” she said. “The longer you take, the more of it decays and disappears forever.”
Duval develops new process
The Case Western Reserve team is developing a new process that they expect to be 10 to 20 times faster—and produce more product as a result because the material doesn’t have as much time to decay away.
They speed the process by applying membrane adsorbers instead of resins or beads to do the separation. These membranes look like a sheet of filter paper and have much larger pores than the resins, resulting in faster flow.
The membranes are more efficient because the entire surface and pores are coated with a layer of binding materials to selectively capture the desired product. The structure of the membrane (larger pores and higher surface area) sets them apart from the existing resin materials.
“This is the first time anyone has used adsorptive membranes for this purpose,” she said. “Many of the national lab scientists who have to purify these things as part of their job are pretty excited about the possibilities. It’s a really simple approach, but it’s a chemical engineering solution that hasn’t been tried before.”
If it proves successful, it could enhance the production of isotopes used by hospitals worldwide. More than 40 million nuclear medicine procedures are performed annually, according to the World Nuclear Association, and the demand is increasing by about 5% a year. Further, more than 10,000 hospitals worldwide use radioisotopes in medicine, and about 90% of the procedures are for diagnosis, according to the association.
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(This article was originally published June 26, 2020.)