3D Hydrogel Encapsulation Regulates Nephrogenesis in Kidney Organoids

Area of Science:

• Biomaterials engineering
• Developmental biology
• Regenerative medicine

Background:

• Stem cell-derived kidney organoids mimic human kidney structures and functions.
• Current differentiation protocols primarily rely on biochemical cues.
• The role of mechanical signals in nephrogenesis remains underexplored.

Purpose of the Study:

• To investigate the hypothesis that mechanical signals regulate nephrogenesis in kidney organoids.
• To explore the impact of hydrogel viscoelasticity on kidney organoid development.
• To understand how mechanical cues influence nephron patterning and morphology.

Main Methods:

• Kidney organoids were encapsulated in viscoelastic alginate hydrogels with varying stress relaxation rates.
• Comparative analysis with organoids in suspension culture.
• Utilized a particle-based computational model to predict mechanical influences.
• Assessed effects of hydrogel-mediated extracellular calcium levels.

Main Results:

• Kidney organoids in hydrogels exhibited significantly more convoluted tubular nephron segments compared to suspension cultures.
• Hydrogel viscoelasticity modulated the spatial distribution of nephron segments.
• Computational modeling indicated that hydrogel-organoid interface deformation regulates nephron morphology.
• Increased extracellular calcium, influenced by hydrogels, reduced the glomerulus-to-tubule ratio.

Conclusions:

• Hydrogel encapsulation and its mechanical properties regulate nephron patterning and morphology in kidney organoids.
• The mechanical microenvironment is a critical factor in kidney organoid development.
• Mechanical cues should be considered as a key design variable in kidney regenerative medicine strategies.