Researchers from University of Jyväskylä and Aalto University in Finland have developed a customized DNA nanostructure that can perform a predefined task in human body-like conditions. To do so, the team built a capsule-like carrier that opens and closes according to the pH level of the surrounding solution. The nanocapsule can be loaded—or packed—with a variety of cargo, closed for delivery and opened again through a subtle pH increase.