University researchers are hoping to add a new weapon in the fight against cancer by using micro-pellets to seek out and destroy cancer cells.
As the second-leading cause of death in the country, cancer will claim more than 550,000 lives this year, and more than 1.4 million new cases of cancer will be diagnosed in the United States, according to the National Cancer Institute.
With the ever-increasing number of cancer patients in the nation, doctors are searching for new therapies to treat the infected individuals.
One such scientist is Raoul Kopelman, an applied physics and chemistry professor at the University, who has proposed a novel solution to combat this deadly disease by using tiny plastic pellets known as PEBBLEs. PEBBLE, which stands for probes encapsulated by biologically localized embedding, are tiny polymer globules that directly target cancerous cells in the body.
Recent clinical trials on rats have shown that a single treatment using PEBBLEs can extend the rats’ lives by 100 percent with no adverse side effects. The reason for its effectiveness is that the pellets only seek out and attack the cancerous cells in the body and then use the body’s own resources to kill the infected cell.
Kopelman makes the micro-pellets with a process called reverse micelle formation. This involves polymerizing oil around a tiny droplet of water into a hollow plastic pellet.
The micro-pellets range from 20 to 600 nanometers in diameter and are then coated with molecules that guide the pellets to the specific cancer cells in the body.
To kill the cancer cells, the pellets are filled with a photocatalyst, a substance that absorbs light and can trigger a chemical reaction within the oxygen in blood cells.
When oxygen in the blood cells is excited by an appropriate wavelength of light, it turns into highly reactive singlet oxygen. The oxygen is so reactive that it kills adjacent cancer cells.
After the micro-pellets are injected into the body, an MRI, also known as Magnetic Resonance Imaging, locates the PEBBLEs to then excite the oxygen. Once located, researchers then would cut a surgical hole in the patient and insert an optical fiber into the body to provide the light needed for the photocatalyst.
Compared to traditional therapies, Kopelman said PEBBLEs does not seem to produce any adverse side effects in part because of the pellets themselves are harmless and when activated only affect cancer cells.
Yong Eun Koo Lee, a research associate in the chemistry department who is working with Kopelman to develop the micro-pellets, said PEBBLEs may be more effective than more traditional cancer treatments.
Oftentimes protein in the body will interfere with cancer treatments, Lee said. But PEBBLEs encases its payload within the micro-pellets, protecting it from proteins that can potentially disrupt the treatment process.
Kopelman and his colleagues have received funding from different government agencies, including the National Cancer Institute, which provided $11.5 million toward the research and development of this technique.
But as of yet, Kopelman said he and his team do not know how safe PEBBLEs is for humans, because all the clinical tests have been on rats. He added that it will take several years before the Food and Drug Administration will approve PEBBLEs for medical use.