Chang, Chun-YiJohnson, Hunter C.Babb, OliviaFishel, Melissa L.Lin, Chien-Chi2023-08-032023-08-032021Chang CY, Johnson HC, Babb O, Fishel ML, Lin CC. Biomimetic stiffening of cell-laden hydrogels via sequential thiol-ene and hydrazone click reactions. Acta Biomater. 2021;130:161-171. doi:10.1016/j.actbio.2021.05.054https://hdl.handle.net/1805/34724Hydrogels with dynamically tunable crosslinking are invaluable for directing stem cell fate and mimicking a stiffening matrix during fibrosis or tumor development. The increases in matrix stiffness during tissue development are often accompanied by the accumulation of extracellular matrices (e.g., collagen, hyaluronic acid (HA)), a phenomenon that has received little attention in the development of dynamic hydrogels. In this contribution, we present a gelatin-based cell-laden hydrogel system capable of being dynamically stiffened while accumulating HA, a key glycosaminoglycans (GAG) increasingly deposited by stromal cells during tumor progression. Central to this strategy is the synthesis of a dually-modified gelatin macromer – gelatin-norbornene-carbohydrazide (GelNB-CH), which is susceptible to both thiol-norbornene photopolymerization and hydrazone click chemistry. We demonstrate that the crosslinking density of cell-laden thiol-norbornene hydrogels can be dynamically tuned via simple incubation with aldehyde-bearing macromers (e.g., oxidized dextran (oDex) or oHA). The GelNB-CH hydrogel system is highly cytocompatible, as demonstrated by in situ encapsulation of pancreatic cancer cells (PCC) and cancer-associated fibroblasts (CAF). The unique dynamic stiffening scheme provides a platform to study tandem accumulation of HA and elevation in matrix stiffness in the pancreatic tumor microenvironment.en-USPublisher PolicyDynamic hydrogelsHyaluronic acidCancer associated fibroblastsThiol-ene chemistryHydrazone reactionArticle