Applications and Functions of Cell Preservation Solutions in Cell Therapy

Cell preservation solutions play a vital role in modern medicine, particularly in cell therapy, a cutting-edge treatment method that utilizes the patient’s own cells or donor cells to repair or replace damaged tissues and organs. To ensure these cells remain viable during storage and transport, cell preservation solutions are widely used.

Applications of Cell Preservation Solutions in Cell Therapy

1. Stem Cell Preservation
   Stem cell therapy is an important branch of cell therapy, especially for hematopoietic stem cell transplantation and mesenchymal stem cell therapy. Hematopoietic stem cells are commonly used to treat blood disorders such as leukemia and lymphoma, while mesenchymal stem cells are widely applied in the treatment of cardiovascular and neurological diseases. In these processes, stem cells are typically frozen for long-term storage, requiring cell preservation solutions that contain cryoprotectants like DMSO (dimethyl sulfoxide) to prevent ice crystal formation, which can damage cell membranes and organelles. These solutions ensure the integrity and viability of the cells during freezing, providing necessary assurance for subsequent transplantation and treatment.
2. Immune Cell Therapy
   Immune cell therapies, such as CAR-T therapy and natural killer (NK) cell therapy, rely on the preservation and transport of large quantities of high-quality immune cells. In CAR-T therapy, T cells are extracted from the patient, genetically modified outside the body, and then reinfused into the patient to combat cancer cells. During the preservation of these immune cells, cell preservation solutions are critical. By using cryopreservation solutions, immune cells can remain viable during long-term storage until the patient is ready for treatment.
3. Tissue Engineering and Regenerative Medicine
   Tissue engineering and regenerative medicine also depend on high-quality cell preservation solutions. In these fields, cells are used to construct the fundamental components of tissues or organs. To ensure these cells remain active in laboratory settings and successfully build functional tissues, scientists often utilize temperature-sensitive cell preservation solutions for short-term or long-term storage.

Functions of Cell Preservation Solutions

1. Preventing Cell Damage
   The primary function of cell preservation solutions is to prevent cell damage during storage. Particularly during cryopreservation, the formation of ice crystals can cause irreversible damage to cell membranes, organelles, and proteins. Cell preservation solutions typically contain cryoprotectants such as DMSO or glycerol, which can reduce the rate of ice crystal formation and protect cell membrane integrity. By utilizing these cryoprotectants, cells can be stored at extremely low temperatures (e.g., -80°C or liquid nitrogen temperatures) while still maintaining their viability upon thawing.
2. Maintaining Metabolic Stability
   During the short-term storage of cells, cell preservation solutions help maintain metabolic stability, reducing the incidence of autophagy and apoptosis. This is particularly important for cells that cannot be used immediately but need to remain active in the short term. The buffering systems and nutrient components in the preservation solution can provide suitable environmental conditions, preventing disruptions to acid-base balance.
3. Protecting Gene Expression
   Cryopreservation not only aims to preserve the structure and viability of cells, but cell preservation solutions also assist in maintaining the stability of gene expression. For therapies like CAR-T cell therapy, cell preservation solutions can ensure that cells do not undergo significant changes in gene expression during storage and transport, thus ensuring the reliability of therapeutic effects.

Precautions

1. Control of Cryoprotectant Concentration
   The concentration of cryoprotectants like DMSO and glycerol is crucial. A concentration that is too high can be toxic to the cells, while a concentration that is too low may not provide adequate protection against freezing. It is generally recommended to operate within a range of around 10% DMSO concentration. Additionally, the cooling and heating rates during storage must be carefully controlled to avoid cell damage due to rapid temperature changes.
2. Selection of Storage Temperature
   The temperature for cell preservation depends on the duration of storage and the type of cells. Short-term storage typically can be done at 4°C, while long-term storage requires freezing at -80°C or liquid nitrogen (-196°C). Different cell types have varying tolerances to temperature, so adjustments should be made based on the characteristics of the cells being preserved.
3. Precise Control of the Thawing Process
   If not done properly, the thawing process can severely damage cells that have been cryopreserved. Generally, rapid thawing is necessary to minimize damage as cells pass through the temperature range where ice crystals form. A common method involves quickly thawing in 37°C water, but it is crucial to transfer the cells to an appropriate culture medium immediately after thawing to ensure the restoration of cellular metabolism.

By effectively utilizing cell preservation solutions, cell therapy can be successfully implemented, ensuring the safety and efficacy of cells throughout the entire process from collection to application.