Background

Radiation therapy is one of the many tools that oncologists use for the treatment of cancer because it excels at killing cells in a localized area, namely, the site of the tumor.  Like any other therapy, radiation therapy, while efficient, is not always effective.  Often, there are cells from the tumor that are resistant to radiation and survive to become new tumors once the therapy has stopped.  There are multiple factors that contribute to a cell’s resistance to radiation.  One of the biggest among these causes is the fact that most tumors exist in hypoxic (oxygen poor) environments.  Research conducted under Dr. Margaret Wheatley has produced ultrasound contrast agents containing oxygen.  These contrast agents can be injected into the body and fragmented once they are at the site of the tumor, releasing the oxygen contained within the outer shell.  These contrast agents are small, with an average diameter of 1.8 microns (1.8 micrometers).  The small size of these contrast agents allows them to get to all parts of the body safely, but limits their ability to deliver oxygen to the tumor site, and therefore limits the beneficial effects of oxygenating the tumor.  The goal of this project then, is to produce contrast agents with a diameter in excess of 1.8 microns in order to increase the volume of oxygen being delivered to the tumor and as a result, the beneficial effects of oxygenating the tumor.