Ultrasound (IMAGE) Johns Hopkins Medicine Caption When drug-laden nanoparticles (left) absorb energy from ultrasound waves, their liquid center (green) turns to gas and expands the particles (right), loosening their exterior and releasing the drug (blue). Credit Raag Airan Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.