Scientists have built and tested a new biomaterial-based delivery system — known as a hydrogel — that will encase a desired cargo and dissolve to release its freight only when specific physiological conditions are met.

For a hydrogel with logic gates, a specific environmental trigger can open the gates, dissolving the hydrogel and releasing its contents.
(Credit: Cole DeForest/University of Washington)

These environmental cues could include the presence of an enzyme or even the acidic conditions that could be found in a tumor microenvironment. Critically, the triggers that cause dissolution of the hydrogel can be switched out easily in the synthesis process, allowing researchers to create many different packages that open up in response to unique combinations of environmental cues.

The key to the team’s innovation lies in the way the hydrogels were synthesized. When researchers assembled the polymer network that comprises the biomaterial, they incorporated chemical cross-link gates that are designed to open and release the hydrogel’s contents in response to user-specified cues.

These hydrogel gates use simple principles of Boolean logic, which centers on inputs to simple binary commands: “YES,” “AND” or “OR.”