Thermodynamic approach to explain cell adhesion to air-medium interfaces

Area of Science:

• Biotechnology
• Bioprocess Engineering
• Cell Culture Technology

Background:

• Cell damage occurs in suspension cell cultures during air sparging.
• This damage is linked to cells adhering to air bubbles.
• Preventing cell-bubble adhesion effectively prevents cell damage.

Purpose of the Study:

• To present a thermodynamic approach for predicting cell adhesion at the air-medium interface.
• To demonstrate how to prevent cell-gas adhesion using protective additives.

Main Methods:

• Developed a thermodynamic relationship based on interfacial tensions (gas-liquid, gas-cell, liquid-cell).
• Quantified free energy changes using experimental data, theoretical, and empirical equations.
• Validated the model's applicability to all cell types.

Main Results:

• Cell-gas adhesion can be prevented by lowering the liquid growth medium's surface tension.
• Surface-active protective additives effectively reduce surface tension.
• The thermodynamic model accurately predicts cell-gas adhesion.

Conclusions:

• The thermodynamic model provides a method to predict and prevent cell damage in bioreactors.
• Surface tension modification is a key strategy for protecting cells during aeration.
• The model's nonspecific nature ensures broad applicability across different cell types.