Active foam dynamics of tissue spheroid fusion

Area of Science:

• Biomaterials Science
• Cell Biology
• Regenerative Medicine

Background:

• Tissue spheroids fuse to form larger structures, governed by their material properties.
• The link between individual cell active behavior and emergent tissue properties during fusion is unclear.

Purpose of the Study:

• To investigate spheroid fusion dynamics in human periosteum-derived cells.
• To understand how cell activity and cytoskeletal contractility influence tissue mechanics and fusion outcomes.

Main Methods:

• Confocal microscopy to measure spheroid granularity.
• Two-photon microscopy to quantify active cell movements during fusion.
• Pharmacological inhibition of cytoskeletal contractility (Y-27632, blebbistatin).

Main Results:

• Inhibiting cytoskeletal contractility increased tissue granularity and reduced cell rearrangements.
• Reduced contractility initially accelerated fusion but slowed it down further.
• Complete spheroid fusion correlated with frequent cell rearrangements.

Conclusions:

• Cellular activity and rearrangements are critical for tissue fluidity and complete spheroid fusion.
• An active foam model can link cell properties to tissue mechanics.
• Findings offer insights into controlling tissue assembly for regenerative medicine applications.