Date: March 31, 1999
Contact: Tiffany Capuano
757-683-3100
[email protected]
OLD DOMINION ENGINEER AND EVMS SCIENTIST WORKING TO DEVELOP POSSIBLE NEW ELECTRICAL TREATMENT FOR CANCER
An engineering scholar and a medical researcher have turned to an unlikely source in an effort to develop a process that could selectively destroy cancer cells.
The newest hi-tech tool for treating certain cancers may be an incredibly brief pulse of electricity directed at the cancerous tissue, according to Stephen Beebe, associate professor of pediatrics at the Center for Pediatric Research, a joint program of Eastern Virginia Medical School and Children's Hospital of the Kings Daughters, and Karl Schoenbach, eminent scholar of electrical and computer engineering at Old Dominion University.
The two are collaborating on a study of a process called electroporation therapy, or EPT. The EPT process involves injecting a tumor with chemotherapuetic drugs and sending short electrical pulses into the tumor cells via needle electrodes. The pulse causes the cell membranes to become more porous, in turn allowing the injected drugs to kill tumor cells.
"Many tumors become resistant to drugs, and one of the reasons is the cell regulates a pump that pumps the drug back out," Beebe said. "With electroporation these transient holes in the membrane allow large amounts of the drug to go in, and now the cell can't so easily pump it out."
The field has high voltage, yet not enough energy to do real harm to other cells, so researchers say there are no systemic effects as with traditional chemotherapy.
"We cut electricity into extremely short pulses, about 10 billionths of a second, and the energy is not high," said Schoenbach. "There's no heating effects, only electrical effects to modify the cell structure."
Schoenbach's work, which has evolved from technology developed for the Air Force's Strategic Defense Initiative (SDI) anti-ballistic missile project, goes beyond electroporation therapy by using higher voltage pulses exponentially shorter in duration. It is funded by a $700,000 Air Force grant.
Beebe's initial cell analysis shows these ultrashort pulses may have different effects. Longer pulses appear to affect mainly the cell membrane, yet shorter pulses affect the internal components.
"The hope is that we may be able to selectively destroy specific cells without destroying everything around them," Schoenbach said. "This is a long shot. But this new method at least allows us to explore the possibility."
Rather than just affecting the cell membrane, this method may impact the cell nucleus and mitochondria. Beebe also wants to know if cells are more susceptible to electrical damage at certain stages of development. Preliminary experiments with bacteria suggest that cells in a stage of rapid replication and growth may be more susceptible to electrical damage. This agrees with the researchers' electrical model.
"The chromosomes in any rapidly growing cell are more vulnerable because they're unwrapped, being duplicated and copied. So it's conceivable that these pulses do target the nucleus. They damage the chromosomes and the cells die because of that," Beebe said.
The inherent cancer application lies in the premise that rapidly growing cells, such as tumors, could be targeted without harming stationary cells.
(Schoenbach and Beebe will be discussing the process with experts around the country in Norfolk, April 12, at the "ElectroMed99." Schoenbach is chairing the conference, which will bring clinicians, biologists, chemists, and engineers together to discuss the medical potential of ultrashort high electrical power pulses.)
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