Phase-field approach to cellular blebbing

Area of Science:

• Cell Biology
• Biophysics
• Computational Biology

Background:

• Cellular blebs, or plasma membrane bulges, are integral to various biological processes.
• The precise mechanisms governing bleb shape and stability are not fully understood.
• Understanding blebbing is key to deciphering cell mechanics and dynamics.

Purpose of the Study:

• To develop a quantitative model for three-dimensional bleb formation.
• To investigate the factors controlling the shape and stability of cellular blebs.
• To elucidate the distinct mechanisms of bleb formation based on plasma membrane or actin cortex behavior.

Main Methods:

• A dual phase-field model with coupled order parameters was developed.
• The model represents the cell cortex and plasma membrane interactions.
• Simulations and sharp-interface analyses were employed to study blebbing dynamics.

Main Results:

• The model quantitatively predicts blebbing in three dimensions.
• Two distinct bleb formation pathways were identified: discontinuous (saddle-node bifurcation) and continuous (cortical tension).
• Model predictions align well with experimental data for laser-induced cortex rupture.

Conclusions:

• The dual phase-field model provides a robust framework for studying cell blebbing.
• Bleb formation dynamics are dependent on whether the plasma membrane detaches or the actin cortex ruptures.
• This study enhances the understanding of cell mechanics and membrane dynamics.