Pausing Crystal Symmetry (IMAGE) Drexel University Caption Researchers from Drexel University have discovered a way to grow hollow crystal spheres, and pause they're symmetrical growth so they form with holes -- a significant advance for their use in encapsulating targeted drug therapies. Credit Drexel University 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.