Spatially-Encoding Hydrogels With DNA to Control Cell Signaling.

Patterning biomolecules in synthetic hydrogels offers routes to visualize and learn how spatially-encoded cues modulate cell behavior (e.g., proliferation, differentiation, migration, and apoptosis). However, investigating the role of multiple, spatially defined biochemical cues within a single hydrogel matrix remains challenging because of the limited number of orthogonal bioconjugation reactions available for patterning. Herein, a method to pattern multiple oligonucleotide sequences in hydrogels using thiol-yne photochemistry is introduced. Rapid hydrogel photopatterning of hydrogels with micron resolution DNA features (≈1.5 µm) and control over DNA density are achieved over centimeter-scale areas using mask-free digital photolithography. Sequence-specific DNA interactions are then used to reversibly tether biomolecules to patterned regions, demonstrating chemical control over individual patterned domains. Last, localized cell signaling is shown using patterned protein-DNA conjugates to selectively activate cells on patterned areas. Overall, this work introduces a synthetic method to achieve multiplexed micron resolution patterns of biomolecules onto hydrogel scaffolds, providing a platform to study complex spatially-encoded cellular signaling environments.