Fully Synthetic Hydrogels Promote Robust Crypt Formation in Intestinal Organoids.

Initial landmark studies in the design of synthetic hydrogels for intestinal organoid culture identify precise matrix requirements for differentiation, namely decompression of matrix-imposed forces and supplementation of laminin. But beyond stating the necessity of laminin, organoid-laminin interactions have gone largely unstudied, as this ubiquitous requirement of exogenous laminin hinders investigation. In this work, a fast stress relaxing, boronate ester-based synthetic hydrogel is used for the culture of intestinal organoids, and it is fortuitously discovered that unlike all other synthetic hydrogels to date, laminin does not need to be supplemented for crypt formation. This highly defined material provides a unique opportunity to investigate laminin-organoid interactions and how it influences crypt evolution and organoid function. Via fluorescent labeling of non-canonical amino acids, it is further shown that adaptable boronate ester bonds increase deposition of nascent proteins, including laminin. Collectively, these results advance the understanding of how mechanical and matricellular signaling influence intestinal organoid development.