Reducing Radiation Side Effects

Only one drug, Amifostine, has been approved to date by the federal Food and Drug Administration, to help protect normal tissue from the side effects of chemotherapy and radiation, and researchers would like to develop new and improved agents.

Dr. Dicker and his group from Jefferson Medical College were exploring the molecular mechanisms responsible for cellular damage from radiation. They collaborated with a Houston-based drug company and its radiation-protective agent, CD60_DF1. This is a nanoparticle, a soccer ball-shaped, hollow, carbon-based structure known as a fullerene.

To test how well it worked, they turned to tiny zebrafish embryos, which are transparent and allow scientists to closely observe damage produced by cancer treatments to organs. They gave the embryos different doses of ionizing radiation as well as treatment by either Amifostine, which acted as a control agent, or CD60_DF1. They found that CD60_DF1 given before and even immediately after – up to 30 minutes – exposure to X-rays reduced organ damage by one-half to two-thirds, which was as good as the level of protection given by Amifostine.

“We also showed that the fullerene provided organ-specific protection,” Dr. Dicker notes. “It protected the kidney from radiation-induced damage, for example, as well as certain parts of the nervous system.” He explains that one way that radiation frequently damages cells and tissues is by producing “reactive oxygen species” – oxygen radicals, peroxides and hydroxyls. The research team showed that zebrafish embryos exposed to ionizing radiation had more than 50 percent fewer reactive oxygen species compared to untreated embryos.

He says that the company also has technology enabling certain molecules to be attached to the nanoparticles, which will allow targeting to specific organs and tissues.

COMPAMED.de; Source: Thomas Jefferson University