TINY BUBBLES: Oxygen-filled bubbles—3 μm in diameter—are delivered to a tumor via blood vessels. Sonication at the site of the tumor causes the bubbles to explode, releasing oxygen. Enriching tumors with oxygen is thought to enhance radiation treatment.© GEORGE RETSECK
The rapid growth and high metabolic activity of a tumor can cause its cells to become hypoxic due to an insufficient blood supply. Somewhat counterintuitively, however, these sickly, oxygen-starved cells are actually harder to kill with radiation treatment than healthy tissue. Researchers are thus investigating ways to boost oxygen levels in tumors so the cells can be nuked more effectively.
One idea has been to inject tiny oxygen-filled bubbles into a patient’s bloodstream. The bubbles would then enter the tumor—where blood vessel walls tend to be leaky—and burst to locally release the oxygen, explains John Eisenbrey of Thomas Jefferson University in Philadelphia.
Such bubble-based treatment is not as strange as it might sound. Indeed, the ultrasound community has been using gas-filled microbubbles as a contrast ...
