Stiffness anisotropy coordinates supracellular contractility driving long-range myotube-ECM alignment

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Cell Biology

Background:

• Cellular organization into tissues requires coordinated biological processes.
• Skeletal muscle's inherent mechanical anisotropy influences its development.
• Existing biomaterials struggle to replicate mechanical anisotropy without topographical cues.

Purpose of the Study:

• To investigate the role of substrate stiffness anisotropy in coordinating collective cell dynamics.
• To determine if mechanical anisotropy, independent of topography, can direct tissue patterning.
• To explore the impact of anisotropic biomaterials on C2C12 myotube alignment.

Main Methods:

• Culturing C2C12 myoblasts on mechanically anisotropic and isotropic liquid crystalline polymer networks (LCNs).
• Utilizing LCNs with controlled stiffness anisotropy but lacking surface topography.
• Observing and analyzing collective cellular polarization, migration, and myotube formation.

Main Results:

• Mechanically anisotropic LCNs induced collective cell polarization along the stiffest direction.
• Substrate stiffness anisotropy drove millimeter-scale C2C12 myotube alignment.
• Cell-ECM interactions during fusion amplified global tissue ordering on anisotropic substrates.
• Isotropic LCNs resulted in localized, unaligned myotube domains.

Conclusions:

• Substrate stiffness anisotropy is a key factor in directing large-scale tissue morphogenesis.
• Anisotropic LCNs provide a topography-free platform to study mechanical influences on cell behavior.
• These findings inform the design of biomaterials for advanced tissue engineering applications.