KU’s World-First Identification of the Cause of Freezing-Driven Cell Injury,

Expected to Revolutionize Biological Sample Preservation Technology 

-Technologies for long-term storage and biopharmaceutical preservation are expected to make advances. 

△ During the freezing process, anions are selectively incorporated into ice crystals and cations accumulate excessively around the cell membrane, which rapidly increases the cell membrane potential and causes microscopic pore formation. 

A KU research group has become the world’s first to identify the causes of freezing-driven cell injury. The results of their research are expected to lead to further advancement of long-term storage and biological sample preservation technologies. 

Professor Ahn Dong-june’s group from the Department of Chemical and Biological Engineering at KU (President Kim Dong-one) has successfully identified the cause of cell membrane injury during the cell freezing process. 

The results of this study were published online on March 2 in Computers in Biology and Medicine (top 2.3% in JCR Mathematical & Computational Biology), a globally renowned journal.

*Article title: Freezing-driven ionic charge imbalance leads to pore formation and osmotic injury of lipid membranes

*DOI: https://doi.org/10.1016/j.compbiomed.2025.109960

Cryopreservation, which preserves biological samples for long periods of time, is a key technology in the fields of pharmaceuticals, organ transplantation, and cell therapy, but the problem of cell injury during the thawing process has not been resolved. Previous studies have shown that ice physically damages cells, but the exact cause of cell injury has not been identified.

Professor Ahn’s research team discovered that when cells are frozen, anions are selectively incorporated into ice crystals, and cations accumulate excessively around the cell membrane. This leads to a drastic increase in the transmembrane potential and the formation of pores, causing osmotic efflux of the water molecules from the cells. As a result, the cells are severely dehydrated, the injury worsens, and the cell viability decreases.

The research team also found that the components of the cell membrane affect the extent of such injury. They discovered that cell membranes containing cholesterol and negatively charged phospholipids are more resistant to freezing. The analytical results showed that cholesterol keeps the cell membrane stable even at low temperatures, and that negatively charged phospholipids alleviate the ionic charge imbalance that occurs during freezing.

This study is the first that has identified the cause of cell injury during the freezing process at the molecular level, and the results are expected to contribute to the development of a new cryopreservation technology that minimizes cell injury by regulating the lipid composition of cell membranes. The results of this study are also expected to be widely applied in various fields of life science and medicine, such as biopharmaceutical preservation, long-term storage, and cell therapy research.

The study was supported by the National Research Foundation of Korea, the Small and Medium Business Administration of Korea, and the Korea Health Industry Development Institute.

[Figure 1]

△ [Figure 1]: (From left) KU Professor Ahn Dong-june (Department of Chemical and Biological Engineering, corresponding author), Jung Woo-hyuk (KU, doctoral student, co-first author), Dr. Lee Sang-yup (KU, co-first author), and Lee Ye-dam (KU, doctoral student, co-first author).

[Figure 2]  

△[Figure 2] : ] Analysis of the pore formation process and osmosis in frozen cell membranes. Pores are formed in the cell membrane due to ionic charge imbalance, and water molecules are discharged through the pores, causing osmosis.

[Figure 3]  

△[Figure 3] :  Observation of the degree of freezing-induced membrane injury depending on the membrane components (left), and analysis using molecular dynamics simulations of the delay in pore formation in the membrane according to lipid components (right).