Temperature Dependence of Membrane Permeability Parameters for Five Cell Types Using Nonideal Thermodynamic...

Area of Science:

• Cell biology
• Biophysics
• Cryobiology

Background:

• Cryopreservation requires precise control of cooling/warming and cryoprotective agent (CPA) procedures to minimize cell injury.
• Mathematical modeling of cell volume changes is essential for optimizing cryopreservation protocols.
• Accurate modeling necessitates understanding cell membrane permeability to water and CPA, and the osmotically inactive cell fraction.

Purpose of the Study:

• To develop and validate a novel two-part fitting method for determining key cell osmotic parameters.
• To measure five cell-type-specific parameters, including water and CPA permeability, osmotically inactive fraction, and osmotic virial coefficients.
• To extend previous measurement techniques to include data at 0 °C, accounting for temperature-dependent osmotic parameters.

Main Methods:

• A two-part fitting method was developed using experimental measurements of equilibrium and kinetic cell volume data.
• Measurements were conducted at room temperature and 0 °C for five distinct cell types.
• The method incorporates nonideal solution thermodynamics using the osmotic virial equation.

Main Results:

• Successfully obtained five essential cell-type-specific parameters for HUVECs, H9c2 cells, PCECs, Jurkat cells, and hCMECs/D3 cells.
• The new fitting method effectively addresses technical challenges and expands previous techniques to 0 °C.
• Modeled HUVEC cryopreservation protocol demonstrated the significant impact of nonideal thermodynamic assumptions on predicting cell volume changes.

Conclusions:

• The developed method accurately determines critical cell osmotic parameters, essential for precise cryopreservation modeling.
• Incorporating nonideal solution thermodynamics significantly improves the prediction of cell volume dynamics during cryopreservation.
• This work provides a robust framework for optimizing cryopreservation protocols across various cell types.