Soft, Dynamic Hydrogel Confinement Improves Kidney Organoid Lumen Morphology and Reduces Epithelial–Mesenchymal Transition in Culture

Abstract

Pluripotent stem cell-derived kidney organoids offer a promising solution to renal failure, yet current organoid protocols often lead to off-target cells and phenotypic alterations, preventing maturity. Here, various dynamic hydrogel architectures are created, conferring a controlled and biomimetic environment for organoid encapsulation. How hydrogel stiffness and stress relaxation affect renal phenotype and undesired fibrotic markers are investigated. The authors observe that stiff hydrogel encapsulation leads to an absence of certain renal cell types and signs of an epithelial-mesenchymal transition (EMT), whereas encapsulation in soft, stress-relaxing hydrogels leads to all major renal segments, fewer fibrosis or EMT associated proteins, apical proximal tubule polarization, and primary cilia formation, representing a significant improvement over current approaches to culture kidney organoids. The findings show that engineering hydrogel mechanics and dynamics have a decided benefit for organoid culture. These structure-property-function relationships can enable the rational design of materials, bringing us closer to functional engraftments and disease-modeling applications.

Viscoelastic hydrogels for interrogating pancreatic cancer-stromal cell interactions

“…While in this work we demonstrated some level of EMT marker expression in viscoelastic hydrogels, a recent work reported by Ruiter et al. demonstrated that stress-relaxing alginate-based hydrogels down-regulated EMT associated proteins in kidney organoids [ 37 ]. Additional studies are needed to obtain conclusive results on the effect of matrix stress-relaxation on pancreatic cancer cells.…”

Dynamic Covalent Hydrogels: Strong yet Dynamic

“…Viscoelastic hydrogels can be used to study the influence of matrix relaxation on cell morphology ( Figure 5 B), migration and proliferation, as well as to understand the cell–cell and cell–ECM interactions ( Figure 5 A). In addition, the hydrogels similar to tissues can be used for organoid incubation ( Figure 5 C) [ 57 , 126 , 127 , 128 ].…”

“…Copyright © The Royal Society of Chemistry 2014 ( B ) Thioester exchange facilitates spreading, proliferation, and migration of hMSCs in 3D scaffolds [ 57 ]. Copyright © 2018 Elsevier Ltd. ( C ) Oxime hydrogels were used to culture kidney organoids [ 126 ].…”

Role of extracellular matrix components and structure in new renal models in vitro

“…Recently, Geunes et al cultured kidney organoids in thiol-ene cross-linked alginate hydrogels and showed a reduction in the onset of aberrant ECM expression and off-target cell populations ( Geuens et al, 2021 ). By engineering gel mechanics and dynamics, ECM deposition and organoid maturation could be tuned, highlighting the role of engineered matrices in stirring organoid commitment ( Ruiter et al, 2022 ).…”