Dynamics of Dimethyl Sulfoxide Penetration Into L929 Cells and L929-Based Spheroids

Anton Moisieiev,Igor Kovalenko,Olga Gordienko,Svitlana Kovalenko,Galyna Bozhok

doi:10.15407/cryo31.04.316

Abstract

The study proposes an algorithm for calculating of appreciable permeability coefficients for multicellular structures in a cryoprotectant medium using physical and mathematical model of mass transfer. The values of surface-area-to-volume ratio for L929 cells at different temperatures were determined and the thermal expansion coefficient of the surface area of cell membranes was calculated (β = 2.7 × 10-3 /°C). The osmotically inactive volume for L929 cells and their spheroids was determined. Filtration and permeability coefficients to DMSO for L929 cells and in toto spheroids were found from the dynamic curves of relative volume change. The calculated parameters are the highest for individual cells and significantly (p <0.05) decrease for cells in the spheroids with increasing depth of their location, this reduction may be stipulated by a decrease in the available surface of cells in the spheroids for the penetration of extracellular substances. Obtained in this research permeability characteristics of spheroids can be used to develop optimal cryopreservation regimens for them.

Highlights

The study proposes an algorithm for calculating of appreciable permeability coefficients for multicellular structures in a cryoprotectant medium using physical and mathematical model of mass transfer
The coefficient of thermal expansion of the membrane surface area can be influenced by its lipid and protein composition, as well as external factors. This characteristic can be used to monitor the state of cell membranes under different conditions and terms of cultivation
In this research we determined the parameters of individual L929 cells, spheroids in toto, the ones located in their outer and inner layers, needed to estimate the exposure time in cryoprotective solution and the optimal cooling rates of these objects during cryopreservation

Summary

Introduction

The study proposes an algorithm for calculating of appreciable permeability coefficients for multicellular structures in a cryoprotectant medium using physical and mathematical model of mass transfer. The values of surface-area-to-volume ratio for L929 cells at different temperatures was determined and the thermal expansion coefficient of the surface area of cell membranes was calculated (β = 2.7 × 10–3/°C.). The osmotically inactive volume for L929 cells and their spheroids was determined. Filtration and permeability coefficients to DMSO for L929 cells and in toto spheroids were found from the dynamic curves of relative volume change. Тому за останні два десятиліття було здійснено численні спроби для розроблення 3D-моделей культури клітин із метою подолання суперечностей між результатами аналізу клітин та експериментальних досліджень на тваринах та усунення експериментальної невизначеності під час використання моношарових культур. Cells in human body interact with each other and components of the extracellular matrix to create a unique 3D organization.

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Conclusion