Photo-click Decellularized Matrix Hydrogels for Generating Pancreatic Ductal Organoids

Pancreatic ductal organoids (PDOs) generated from human induced pluripotent stem cells (iPSCs) can be used to model pancreatic diseases and to conduct drug screening/testing. However, current protocols for generating PDOs rely heavily on tumor-derived Matrigel, which has been shown to upregulate oncogenes. Furthermore, Matrigel has undefined composition and weak mechanical properties that hamper mechanistic studies of cell-material interactions. In this study, we explore photo-clickable decellularized small intestine submucosa-norbornene (dSIS-NB) hydrogels as a Matrigel replacement for generating human iPSC-derived PDOs. To achieve this, pancreatic progenitors (PP) were first differentiated in conventional two-dimensional (2D) culture, aggregated into spheroids, then encapsulated and differentiated within dSIS-NB hydrogels with tunable stiffness. The differentiated organoids were analyzed by morphology, expression of key pancreatic ductal markers, and single-cell RNA sequencing (scRNA-seq). Post-differentiation, PDOs generated in stiffer photo-clickable dSIS-NB hydrogels (shear moduli [~]2.5 kPa) maintained ductal epithelial phenotype and exhibited pronounced forskolin-induced swelling. In contrast, differentiation of PP spheroids in softer dSIS-NB gels (shear moduli [~]0.9 kPa) and Matrigel resulted in a persistent mesenchymal phenotype and failed to generate functional PDOs. Finally, scRNA-seq results revealed that stiffer dSIS-NB hydrogels strongly biased ductal cell differentiation, yielding greater than 97% ductal progeny.