Nanoparticle Polymer Image (IMAGE) Johns Hopkins Medicine Caption Microscope image of the cells used to test nanoparticles. The cells here are genetically engineered to fluoresce at points where endosomes carrying nanoparticles into the cell are opened. Credit Jordan Green; Johns Hopkins Medicine Usage Restrictions NA License Original 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.