Synthetic Photoresponsive Hydrogels Enable In Situ Control Over Murine Intestinal Monolayer Differentiation and Crypt Formation

As a model of the intestinal epithelium, intestinal stem cells (ISCs) are grown and differentiated as monolayers on materials where stochastic organization of the crypt and villi cells occurs. An allyl sulfide crosslinked photoresponsive hydrogel with a shear modulus of 1.6 kPa is developed and functionalized with GFOGER, Bm‐binder peptide ligands for monolayer growth of ISCs. The allyl sulfide chemistry allows in situ control of mechanics in the presence of growing ISC monolayers and structured irradiation affords spatial regulation of the hydrogel properties. Specifically, ISC monolayers grown on 1.6 kPa substrates are in situ softened to 0.29 kPa, using circular patterns 50, 75, and 100 µm in diameter, during differentiation, resulting in control over the size and arrangement of de novo crypts and monolayer cellularity. These photoresponsive materials should be useful in applications ranging from studying crypt evolution to drug screening and transport across tissues of changing cellular composition. Spatiotemporal softening enables control over the size and arrangement of de novo crypts within intestinal monolayers.