Microtissue Geometry and Cell-Generated Forces Drive Patterning of Liver Progenitor Cell Differentiation in 3D

Area of Science:

• Biomedical Engineering
• Developmental Biology
• Cell Biology

Background:

• 3D microenvironments offer insights into mechanical signaling's role in progenitor cell differentiation.
• Investigating mechanical cues in controlled 3D systems is crucial for understanding developmental processes.

Purpose of the Study:

• To explore how microtissue geometry and resulting mechanical stresses impact early liver progenitor cell differentiation.
• To establish a platform for studying mechanical signaling in liver development.

Main Methods:

• Fabrication of 3D multicellular microtissues in defined geometries (toroids, cylinders) using a hydrogel microwell platform.
• Image segmentation for tracking cell fate and marker distribution.
• Finite element modeling to predict stress distributions and correlate with mechanical measurements.

Main Results:

• Distinct mechanical profiles were generated by toroidal and cylindrical microtissues.
• Hepatocytic markers patterned to the outer shell, excluded from toroid inner surfaces.
• Biliary markers increased in toroidal tissues compared to cylindrical ones.
• Intercellular tension correlated with increased hepatocytic fate; compression correlated with decreased hepatocytic and increased biliary fate.

Conclusions:

• Microtissue geometry can dictate mechanical stress patterns that regulate cell differentiation trajectories.
• This integrated approach demonstrates a link between mechanical forces and cell fate in a liver model.
• The platform can be used for further studies on signaling mechanisms in liver and other developmental systems.