A nonlinear elastic description of cell preferential orientations over a stretched substrate.

Area of Science:

• Cell biology
• Biophysics
• Materials science

Background:

• Cellular response to mechanical stimuli is crucial in physiology, pathology, and tissue engineering.
• Cells on cyclically stretched substrates reorient along a defined angle relative to the stretching direction.
• Previous models suggested elastic energy minimization drives this cell reorientation.

Purpose of the Study:

• Investigate nonlinear effects in cell reorientation under cyclic stretching using finite elasticity.
• Analyze cell behavior at high strain levels.
• Explore the influence of anisotropic invariants on cell reorientation dynamics.

Main Methods:

• Applied finite elasticity framework to model cell-substrate interactions.
• Developed a theoretical model for cell reorientation under biaxial deformation.
• Incorporated anisotropic invariants related to the Cauchy-Green strain tensor.

Main Results:

• Identified a linear relationship between biaxial deformation and cell orientation angle ([Formula: see text]) for orthotropic materials.
• Demonstrated that the slope of this linear relationship depends on four nonlinear constitutive parameters.
• Observed deviations from linearity when energy dependence on anisotropic invariants was introduced.

Conclusions:

• Finite elasticity provides a framework to understand nonlinear cell reorientation.
• Cell orientation is predictably linked to deformation, with parameters governing the relationship.
• Deviations from linearity offer insights into complex cellular responses to mechanical cues.