A Fractional Order Standard Linear Solid Model for Extracting the Elastic Moduli of Internal Cell Structures

Area of Science:

• Biophysics
• Cell Mechanics
• Materials Science

Background:

• Cellular mechanical properties, or elastic moduli, are key indicators of cell behavior.
• Measuring these properties typically involves complex micro/nano-scale experimental procedures.

Purpose of the Study:

• To propose a novel fractional-order standard linear solid model for determining the elastic moduli of internal cell structures.
• To simplify the experimental measurement of cell mechanics.

Main Methods:

• A fractional-order standard linear solid model was developed, treating the nucleus, cytoskeleton, and cytoplasm as load-bearing components.
• The model was fitted to cell creep curves obtained via atomic force microscopy (AFM).

Main Results:

• The model successfully extracted elastic moduli for the nucleus, intermediate filaments, microtubules, and a composite membrane-cytoplasm-actin cortex element.
• Fitted elastic moduli were of appropriate magnitude, independent of loading, and showed good agreement (R²: 0.95-0.98) with existing data.
• The proposed model demonstrated lower Akaike Information Criterion (AIC) values compared to traditional Prony models.

Conclusions:

• The developed fractional-order model offers a simplified and effective method for measuring the mechanical properties of internal cell structures.
• This approach eliminates the need for complex experimental setups and can monitor cellular responses to various stimuli.