Drug treatments can save lives, but sometimes they also carry unintended costs. After all, the same therapeutics that target pathogens and tumors can also harm healthy cells.
To reduce this collateral damage, scientists have long sought specificity in drug delivery systems: A package that can encase a therapeutic and will not disgorge its toxic cargo until it reaches the site of treatment—be it a tumor, a diseased organ or a site of infection.
In a paper published Jan. 15 in the journal Nature Chemistry, scientists at the University of Washington announced that they 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. 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.
Engineered modular biomaterial logic gates for environmentally triggered therapeutic delivery, Nature Chemistry (2018). nature.com/articles/doi:10.1038/nchem.2917
Representation of a simple "YES" gate. The grey and orange bars represent the entire gate, which connects to the polymers that hold the hydrogel together (black and purple wavy lines). The gate will open -- releasing the hydrogel's contents -- only if a specific triggering mechanism (labeled "A") is present and cleaves the orange portion of the gate. Credit: Cole DeForest/University of Washington