New Treatment Punches Holes in Tumors

Author:  Falishia Sloan

Institution:  Eastern Virginia Medical School
Date:  July 2007

In a collaborative effort, two engineers and a team of skilled scientists have discovered a way to specifically target and destroy cancer cells using electric pulses. These engineers, Rafael V. Davalos, a faculty member of the Virginia Tech–Wake Forest University School of Biomedical Engineering and Science (SBES), and Boris Rubinsky, a bioengineering professor at the University of California, Berkeley developed a technique, called irreversible electroporation (IRE), by which cancerous cells can be specifically targeted and destroyed.

With electroporation, a cell can go from being impermeable to being reversibly permeable to being irreversibly permeable (IRE), at which stage the cell will die. It is this concept that Davalos and Rubinsky used to target and kill cancer cells.

"IRE removes tumors by irreversibly opening tumor cells through a series of short intense electric pulses from small electrodes placed in or around the body," said Davalos. "This application creates permanent openings in the pores in the cells of the undesirable tissue. The openings eventually lead to the death of the cells without the use of potentially harmful chemotherapeutic drugs."

Electroporation is a well-known tool for increasing the permeability of a cell, allowing substances to pass through the cellular membrane more easily. Methods currently used to annihilate tumors, such as using heat or freezing, can also inflict damage on surrounding healthy tissue or miss some bad cells. The process of IRE, however, is minimally invasive, and the electrical current can be controlled to destroy targeted cells reliably.

"The reliable killing of a targeted area with cellular scale resolution without affecting surrounding tissue or nearby blood vessels is key," Davalos said.

Using livers from male Sprague-Dawley rats, the scientists successfully ablated tissue using IRE pulses. Davalos explained, "We did not use any drugs, the cells were destroyed, and the vessel architecture was preserved."

Davalos noted the importance of what he described as a "minimally invasive, inexpensive surgical technique to treat cancer. It has the advantages that it is easy to apply, is not affected by local blood flow, and can be monitored and controlled using electrical impedance tomography," he added.

Written by Falishia Sloan