Construction of pH-Triggered DNA Hydrogels Based on Hybridization Chain Reactions

As a novel type of bio-functional material, DNA hydrogels have attracted more and more attention due to their successful applications in 3D cell culturing and tissue engineering for the designable and programmable responsiveness. Herein, we have developed a pH-triggered DNA hydrogel based on a clamped hybridization chain reaction(C-HCR). In this system, a DNA switch was designed, which can release the initiator strand in a controllable way via the formation of the C-G·C+ triplex under the pH stimuli. While the pre-gelation solution is stable in neutral environment, the C-HCR will trigger the sol-gel transition as the pH decreased to 5.0. This strategy has endowed the DNA hydrogel with good controllability for triggering, which also shows potential in intellectual responsiveness to certain stimuli.