Atomic force pulling: probing the local elasticity of the cell membrane

Area of Science:

• Biophysics
• Cell Biology
• Materials Science

Background:

• Understanding the mechanical properties of the cell membrane is crucial for cell function.
• Existing methods for measuring membrane elasticity have limitations.

Purpose of the Study:

• To develop and validate a novel atomic force microscopy (AFM)-based approach for assessing local elastic properties of the membrane-skeleton complex.
• To determine the bending modulus of the human erythrocyte cell membrane.

Main Methods:

• Utilizing AFM to pull the cell membrane by modifying tip adhesion.
• Acquiring and analyzing force-distance curves, focusing on the withdrawal phase.
• Applying a theoretical model for axisymmetric bending of an annular thick plate to experimental data.

Main Results:

• The novel AFM approach was successfully applied to human erythrocytes.
• The method provides a complementary technique to established methods for elastic property measurement.
• The bending modulus of the human erythrocyte cell membrane was determined to be (2.07 ± 0.32) x 10⁻¹⁹ J.

Conclusions:

• The presented AFM method offers a new way to explore local elastic properties of cell membranes.
• This technique can be valuable for studying membrane mechanics in various cell types.
• The findings contribute to a better understanding of cell membrane biomechanics.