Vaccines and other medicines are often packed in little fat droplets, or lipids. In this form, they are absorbed by cells and release their “cargo” once they are there. The trigger is a change in the pH value in the droplet’s surroundings. Researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have now created a computer simulation of what exactly happens. Their findings may help to optimize the release of the active substances. The results have been published in the journal “Small”*.